Apr. 9, 2013 ? New research from the University of Cincinnati shows how some things you do to make your lawn green might not be conducive to "going green."
Amy Townsend-Small, a UC assistant professor of geology and geography, will present her research, "Carbon Sequestration and Greenhouse Gas Emissions in Urban Ecosystems," at the Association of American Geographers annual meeting to be held April 9-13 in Los Angeles. The interdisciplinary forum is attended by more than 7,000 scientists from around the world and features an array of geography-related presentations, workshops and field trips.
At the meeting, Townsend-Small will discuss the effects lawn-management techniques have on greenhouse gas production in urban landscapes. She says there's a high energy cost associated with common lawn-care methods such as mowing, irrigation and fertilization due to the processing and transport required for these products and services.
"Landscaping is something everyone can understand," Townsend-Small says. "You probably have your own maintenance routine you do. To make your lawn look nice, you need to use fossil fuels, which emit carbon dioxide. Depending on the management intensity, lawns could either be a small sink -- meaning they store carbon -- or a small source of greenhouse gases to the atmosphere."
Fossil fuels are used to power lawn mowers and trimmers, to pump irrigation water, and to make fertilizers -- and all of these activities emit carbon dioxide.
For her research, Townsend-Small monitored the carbon uptake and storage -- known as carbon sequestration -- in the soil of urban lawns in Los Angeles and Cincinnati. Despite the extreme climate variation between the two regions, she found the lawns had surprisingly similar abilities to absorb carbon and store it in soils. But there's a stark contrast in how those lawns are managed, leading to differences in their ecological impact.
Townsend-Small found that while having a well-cared-for lawn will improve its carbon-quelling capacity, intensive lawn care isn't worth the atmospheric side effects. For example, in California's arid environment, the management required and fossil fuel energy expended to keep lawns looking lush consumes so much energy that it counteracts the soil's natural carbon sequestration abilities. But if you head nearly 2,500 miles east to Cincinnati, rainfall is more plentiful. This means more lawns don't require irrigation, helping reduce the carbon cost of lawn maintenance and preserve the carbon sequestration benefits.
This study is the first of its kind to compare the environmental cost of making urban lawns rich and productive with leaving them unmanaged and undisturbed. Two undergraduate students in UC's Women In Science and Engineering program gathered hundreds of local soil samples at different sites and analyzed the emission of powerful greenhouse gases such as nitrous oxide and methane. The University of Cincinnati proved to be an ideal location for Townsend-Small's project thanks to the proximity of the managed green spaces on campus and the natural environment of nearby city parks.
"That's one thing that's special about UC. It's in the middle of the city, and it's a great research site for us because of the access to urban green spaces," Townsend-Small says. "Now we're exploring whether you can reduce the amount of energy you need to make a lawn pretty and preserve the carbon storage in soils."
Townsend-Small's research could prove useful to cities, businesses and urban universities, such as UC, that are interested in reducing their greenhouse gas emissions. Her data offer an important warning to such groups: When measuring your carbon footprint, remember to thoroughly evaluate what's underfoot.
"Urban green space usually gets a lot of credit for all the benefits to the atmosphere," Townsend-Small says. "But most people don't consider the positive influxes of carbon dioxide from lawn maintenance."
Additional contributors to Townsend-Small's research paper were professor Claudia Czimczik (University of California, Irvine) and UC undergraduate researchers Rebecca Ransohoff and Lily Soderlund.
Funding for the Ohio research was provided by Townsend-Small's start-up funding in UC's McMicken College of Arts & Sciences.
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The above story is reprinted from materials provided by University of Cincinnati. The original article was written by Tom Robinette.
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By Larry Fine AUGUSTA, Georgia, April 8 (Reuters) - Guan Tianlang answered questions about his readiness to play the Masters at the record-setting age of 14 when he gave two-times champion Ben Crenshaw a putting lesson at the 18th hole at Augusta National on Monday. The 61-year-old Crenshaw, whose career was built on his ability as a putter, mentored the precocious Chinese during their practice round, advising the Asia-Pacific Amateur champion about the notoriously fast, sloping greens of Augusta. ...
TSX posts year's biggest jump on upbeat China data
TORONTO (Reuters) - Canada's main stock index recorded its biggest one-day percentage jump in more than four months on Tuesday as positive economic data from China fueled hopes for a global economic recovery and drove gains in the material and energy sectors. The sharpest reaction came from gold producers, which were buoyed by a rise in the price of bullion and jumped 3.4 percent.
Agrium sweeps proxy vote, Jana cries foul
CALGARY, Alberta (Reuters) - Canadian fertilizer company Agrium Inc said on Tuesday its entire slate of directors had been elected to its board, defeating a rival slate nominated by dissident U.S. shareholder Jana Partners. Jana, the hedge fund that is Agrium's biggest single shareholder, said the vote was tainted and should be investigated. Agrium said the result was "fair and square".
Penney, Macy's court fight comes down to plastic pitchers
NEW YORK (Reuters) - The legal battle between Macy's and J.C. Penney over who gets to sell what Martha Stewart products took a comedic turn on Tuesday when lawyers asked a judge to weigh two pitchers in his hands, one from each of the rival retailers. At stake is the question of whether Penney violated the judge's order not to sell certain Stewart products.
Exclusive: Thermo bids for Life Technologies as buyout firms circle - source
NEW YORK (Reuters) - Thermo Fisher Scientific Inc made a binding offer for Life Technologies Corp on Tuesday as private equity firms raced to finalize a consortium to take the genetic testing equipment maker private, several people familiar with the matter said. Thermo Fisher met a bid deadline on Tuesday but private equity firms working on a joint bid missed it and were working late into the evening to secure the equity required to support an offer, the people said.
Porter Airlines expansion plan could hit hurdles
TORONTO (Reuters) - Canadian regional carrier Porter Airlines is expected to announce an order for 12 of Bombardier Inc's new CSeries jets on Wednesday, a likely challenge to flight restrictions at its Toronto Island airport base. The privately held airline, which says it will announce "expansion plans" at a morning press conference, could create a third cross-country carrier with the deal, ratcheting up competition for Canada's No. 1 and No. 2 airlines, Air Canada and WestJet Airlines Ltd .
Capmark's $147 million lawsuit against Goldman thrown out
NEW YORK (Reuters) - A federal judge halted a bid by real estate lender Capmark Financial Group to recover $147 million from Goldman Sachs in connection with alleged conflicts of interest stemming from Capmark's debt restructuring. In a written ruling on Tuesday, U.S. District Judge Robert Sweet in Manhattan said Capmark's arguments were barred because they contradicted statements it made in 2010, while bankrupt.
Canada ready for Canadian $1 billion sanctions against U.S. over labels
OTTAWA (Reuters) - Canada is prepared to impose sanctions of up to C$1 billion ($980 million) a year against the United States unless it complies with a WTO order to redesign its meat labels, Agriculture Minister Gerry Ritz said on Tuesday. The United States introduced country of origin labels for meat in 2009. Mexico and Canada successfully argued before the World Trade Organization that the labels were discriminatory and Washington has until May 23 this year to change them.
FBI probes trading as KPMG quits Herbalife, Skechers audits
(Reuters) - In a blow to one of the world's largest accounting firms, KPMG said it resigned as auditor of two U.S. corporations amid an FBI investigation into insider trading allegations involving leaked information and a former senior partner. The two California-based companies - nutritional products group Herbalife Ltd and footwear maker Skechers USA Inc - said separately on Tuesday that KPMG had quit as their auditor in connection with the leaks.
Scotiabank CEO sees Canadian housing slowdown, not crash
TORONTO (Reuters) - Bank of Nova Scotia Chief Executive Rick Waugh said on Tuesday that mortgage delinquencies have risen at Canada's third-biggest bank, but that he does not foresee a U.S.-style housing crash. "We still anticipate what I would call in terms of housing, a soft landing, and all the metrics which we watch daily confirm that," Waugh told the bank's annual general meeting in Halifax, Nova Scotia.
United Airlines plans earlier flights with Boeing 787
(Reuters) - United Airlines said on Tuesday that it planned to begin flying Boeing's 787 Dreamliner five days sooner than previously expected, a sign of confidence in the jet's return to service after regulators grounded it in January over safety concerns. United, a unit of United Continental Holdings Inc , said it planned to use Boeing's newest jet on its Denver-Houston route starting May 31 and on the Denver-Tokyo's Narita route beginning on June 10.
Quick: what's the difference between a broadcast TV network (Fox, CBS, ABC and NBC) and a cable channel (TBS, TNT, ESPN, etc.)? Oh, only millions and millions of viewers. Nevertheless, Fox's COO Chase Carey is perturbed enough by the mere thought of Aereo getting its way, that he's already claiming that the network will go dark in favor of becoming a cable channel -- if and when OTA network streaming over the internet is completely legalized, that is. Causticism aside, Carey's remarks are certainly indicative of how the networks feel about the potential disruption of their revenue stream, and moreover, showcases just how far we are from living in a world that isn't dominated by the same old processes when it comes to entertainment.
Carey stated: "We need to be able to be fairly compensated for our content. This is not an ideal path we look to pursue, but we can't sit idly by and let an entity steal our signal. We will move to a subscription model if that's our only recourse."
Is it possible that Fox would suddenly vanish from over-the-air antennas everywhere, screwing up countless programming agreements with a near-endless amount of partners? Sure... but it's also possible that the ninth circle of Hades will be converted into an NHL arena. We're calling your bluff, Carey.
A sub-$1,000 price tag makes any product a relative steal on the floor of NAB -- impressive specs and industry standard compatibility are just icing on the cake. If such figures are any indication, however, Blackmagic's new Pocket Cinema Camera, which leaked earlier today and ships in July, is potentially a very solid buy at $995, with a Super-16 Cinema 1080HD sensor with 13 stops of dynamic range, CinemaDNG RAW recording, SD card storage, Micro HDMI monitoring and a Micro Four Thirds lens mount. We got an early look at the shooter on the showroom floor, and the compact size is truly striking -- the body is comparable in size to any other mirrorless camera, though it definitely pushes the limits of what we'd consider pocketable. The design is very similar to Blackmagic's larger Cinema Camera launched at last year's NAB, with the same Micro Four Third lens mount. There's a very sharp built-in matte LCD for viewing footage and adjusting settings, and the build is quite solid -- it's significantly heavier than you'd expect.
Naturally, the camera isn't as capable as Blackmagic's pricier NAB model, the Production Camera 4K, which also made its debut today and ships in July. With that flavor, $3,995 buys you a Super 35 sensor with native Ultra HD and 4K support, a built-in SSD recorder, compressed CinemaDNG RAW and compatibility with EF lenses. We spent a few minutes with that model as well, and were equally impressed. The screen was very bright, sharp and not at all reflective, and the camera includes your standard array of inputs and outputs, including dual mic jacks, an SDI port, power and control. Both models are very competitively priced, as you might expect from Blackmagic, and with this wide range of appeal, there's now a little something for everyone. Be sure to head past the break to check out our hands-on video as we take a closer look at both models.
Petitioning to come to the United States as a foreign national is complicated. There?s visa paperwork, quotas in many cases, and lengthy wait times. One misstep could mean a lengthy separation from your loved ones.
And that's just for straight people.?
As pro-reform interest groups prepare to fight for their specific priorities in pending immigration reform legislation, LGBT activists aren?t standing on the sidelines.
?There is a shared struggle among the immigrant and the LGBT communities,? said Steve Ralls of Immigration Equality, an organization that offers legal aid to LGBT immigrants. ?There is a growing recognition that if we can get fair immigration reform through Congress we can work on a lot of issues together moving forward.?
Gay rights activists say there are several fronts in the immigration fight -- from specific provisions for gay Americans and permanent residents seeking to bring a non-citizen partner to the country, to protections for undocumented LGBT individuals, to a broader call for equal rights.
?We?re investing in immigration reform because it is a social justice issue and we have a responsibility to advocate for the kind of world we want to live in,? said Maya Rupert, policy director for the National Center for Lesbian Rights. ?But beyond that, there are LGBT people who are going to be directly impacted by every provision in the ultimate legislation, so we have to make sure that it?s being done in a way that is inclusive and conscious of their needs.?
Border security has become one of the most contentious and difficult issues that lawmakers must resolve for a comprehensive immigration deal to be struck. USA Today's Alan Gomez discusses.
That means both legal and undocumented immigrants, Rupert said.
The number of LGBT immigrants is difficult to count, but researcher Dr. Gary Gates of UCLA?s Williams Institute used existing Census, Gallup and Pew Research Center data to calculate it. Gates estimates that about 900,000 LGBT immigrants live in the United States. About two-thirds of those are documented -- meaning that they are naturalized citizens, legal permanent residents or holders of a temporary visa. One-third -- about 267,000 -- are undocumented according to the estimate.
For documented LGBT immigrants, a key provision that activists have focused on is the inclusion of legislation called the Uniting American Families Act (UAFA) in a final comprehensive reform bill.
Partial victory with DOMA? Currently, a U.S. citizen or permanent legal resident can petition for a visa for a foreign-born spouse -- but only if the spouse is of the opposite sex. That applies even if the same-sex couple is legally married in another country or in a U.S. state that recognizes gay marriage.
UAFA would make same-sex spouses or permanent partners of U.S. citizens eligible to petition for a family-based visa.
(Proponents of UAFA could win a partial victory of this issue if the U.S. Supreme Court overturns the Defense of Marriage Act this summer, but, unless UAFA passes, same-sex foreign national spouses would still only be eligible for a visa petition if they get married in a state that recognizes their relationship.)
Activists point to an ally in Senate Judiciary Committee Chairman Patrick Leahy, an original Senate sponsor of the UAFA legislation and the head of the panel that will first review a draft immigration bill. The White House also specifically included the provision for same-sex immigrant permanent partners in a January fact sheet outlining the president?s priorities for reform.
A path to citizenship for undocumented immigrants is also getting heavy support from LGBT groups, who note that a significant portion of undocumented LGBT people in the United States may be here because they faced discrimination in their country of origin.
?You can imagine the fear that an undocumented person faces with the uncertainty in current law if their deportation would mean the return to a home country where they cannot be out, where they cannot have a relationship or they would be subject to intense persecution,? says Ralls. ?So a path to citizenship is critical for all undocumented people, and ?for undocumented LGBT people it is in many cases a critical safety issue for them.?
Public opinion shifting Since 1994, the U.S. has classified persecution on the basis of sexual orientation as grounds to seek asylum. But the process can be arduous and confusing, and asylum-seekers have to offer rigorous documentation of hardship. Those whose claims are denied risk deportation.
Although many Latino groups heavily involved in the immigration reform movement -- including the League of United Latin American Citizens,?the?National Council de la Raza and the Congressional Hispanic Caucus -- have offered support for the inclusion of LGBT protections in any final legislation, there?s opposition within the Latino community as well as from outside groups.
Susan Walsh / AP
In this March 12, 2013 file photo, Sen. Marco Rubio, R-Fla. speaks on Capitol Hill in Washington.
In February, Sen. Marco Rubio -- a key player in the Senate Gang of Eight -- said that the inclusion of LGBT protections could hamper passage of the legislation. (Arizona?s Sen. John McCain has echoed that concern as well.)
"I think if that issue becomes a central issue in the debate it's going to become harder to get it done because there will be strong feelings on both sides,? Rubio said at an event sponsored by Buzzfeed.?
As recently as a decade ago, the Hispanic and LGBT communities could have been considered quite the opposite of allies.
In 2006, a Pew Research Center study found that just 31 percent of Hispanics favored allowing gay marriage, compared to 56 percent who opposed it.
But in 2012, those numbers were almost a mirror image, with 52 percent of Hispanics backing gay marriage and about a third saying they are not in favor of legal marriage for gays and lesbians.
Amid the legal complications and the data, and regardless of how any final legislation reads, those involved in the issue say that the debate is raising awareness about a long-ignored population.
?Having a number that indicates that this is a sizable group -- more than 250,000 LGBT undocumented, nearly a million LGBT immigrants -- it?s not so much the overall number that?s important, it?s the fact that there is an estimate,? says Dr. Gates of the Williams Institute. ?Unless you?re counted, you tend not to count.?
Related:?
Religious groups, pro-reform organizations brace for family-based visa fight
This story was originally published on Sun Apr 7, 2013 4:24 AM EDT
Apr. 8, 2013 ? A multidisciplinary team of researchers at Mayo Clinic has developed a new software tool to noninvasively characterize pulmonary adenocarcinoma, a common type of cancerous nodule in the lungs. Results from a pilot study of the computer-aided nodule assessment and risk yield (CANARY) are published in the Journal of Thoracic Oncology.
"Pulmonary adenocarcinoma is the most common type of lung cancer and early detection using traditional computed tomography (CT) scans can lead to a better prognosis," says Tobias Peikert, M.D., a Mayo Clinic pulmonologist and senior author of the study. "However, a subgroup of the detected adenocarcinomas identified by CT may grow very slowly and may be treatable with less extensive surgery."
CANARY can noninvasively stratify the risk lung adenocarcinomas pose by characterizing the nodule as aggressive or indolent with high-sensitivity, specificity and predictive values.
CANARY uses data obtained from existing high-resolution diagnostic or screening CT images of pulmonary adenocarcinomas to match each pixel of the lung nodule to one of nine unique radiological exemplars. In testing, the CANARY classification of these lesions had an excellent correlation with the microscopic analysis of the surgically removed lesions that were examined by lung pathologists, Dr. Peikert says.
Lung cancer is the leading cause of cancer-related deaths in the United States.
"Without effective screening, most lung cancer patients present with advanced stage disease, which has been associated with poor outcomes," Dr. Peikert says. "While CT lung cancer screening has been shown to improve patient survival, the initiation of a nationwide screening program would carry the risk of overtreatment of slow growing tumors and would be associated with substantial health care costs. CANARY represents a new tool to potentially address these issues."
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Journal Reference:
Fabien Maldonado, Jennifer M. Boland, Sushravya Raghunath, Marie Christine Aubry, Brian J. Bartholmai, Mariza deAndrade, Thomas E. Hartman, Ronald A. Karwoski, Srinivasan Rajagopalan, Anne-Marie Sykes, Ping Yang, Eunhee S. Yi, Richard A. Robb, Tobias Peikert. Noninvasive Characterization of the Histopathologic Features of Pulmonary Nodules of the Lung Adenocarcinoma Spectrum using Computer-Aided Nodule Assessment and Risk Yield (CANARY)?A Pilot Study. Journal of Thoracic Oncology, 2013; 8 (4): 452 DOI: 10.1097/JTO.0b013e3182843721
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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.
Where you work can be an excellent predictor of your health, happiness and stress levels. A recent Gallup poll demonstrates the extent to which workers in different professions tend to have similar levels of overall well-being. According to the 2012 results of the Gallup-Healthways Well-Being Index, physicians had the highest level of well-being of any major profession, while transportation workers, including drivers, pilots, flight attendants and air traffic controllers had the lowest.
Gallup-Healthways asked more than 170,000 workers a series of 55 questions covering physical and emotional health, life evaluation and workplace environment. Gallup assigned a score between 0 to 100 to each of 14 major professional categories, with 100 representing ideal well-being. Based on Gallup's score, these are the most and least satisfied professions.
24/7 Wall St.: America's Most Content (and Miserable) Cities
While each of the 55 questions had some impact on the profession?s final well-being score, certain measures highly contribute to workers' health. These include such factors as getting regular exercise, not smoking, learning something new every day, and being treated well by their employers, to name a few.
In an interview with 24/7 Wall St., Dan Witters, research director for the Gallup-Healthways Well-Being Index, explained that the professions with high levels of obesity and related conditions like heart attacks and chronic physical pain were more likely to have much lower overall well-being. Just 14 percent of physicians were considered obese, compared to the more than 37 percent of transportation workers.
The majority of health insurance coverage in the United States is provided by employers, resulting in some dramatic differences between professions. Virtually all physicians surveyed (97 percent) reported having health insurance, while just 77 percent of transportation workers could say the same. Witters explained that health insurance, besides making people more likely to receive treatment they need, ?has a lot of influence on the proactive nature of which people tend to their health.?
Conventional wisdom suggests that working long hours has long-term negative mental and physical health effects. In fact, Witters explained, the data do not support this. While working long hours can lead to stress, many of the jobs with the longest hours, including doctors, professionals such as lawyers and engineers, and business owners, have among the highest levels of well-being. One reason for this, Witters noted, is that long hours translate to higher income in these positions. Higher income, he explained, has a very high correlation with well-being, as it gives people access to basic needs.
One group that may surprise some with its high level of well-being is teachers, which ranked only behind physicians for well-being. ?Teachers are a lot higher than a lot of people would guess. They are good eaters, their obesity, while too high, is well below the national average, and they have good workplace well-being. They get to use their strengths a lot.?
24/7 Wall St. reviewed the 14 professional categories surveyed by the Gallup-Healthway?s Well-Being Index in 2012. On top of calculating an overall national level of well-being, the index also calculates the well-being for each profession, assigning scores from 0 to 100, with 100 representing ideal well-being. In generating the rank, Gallup combined six separate indices, measuring access to basic needs, healthy behavior, work environment, physical health, life evaluation and optimism, and emotional health. In addition to the index, we considered income data and job descriptions from the Bureau of Labor Statistics Occupational Outlook Handbook.
Physicians ranked higher than every other profession due to top marks in life evaluation, healthy behaviors, emotional and physical health, as well as access to basic needs. Physicians were by far the most likely professionals to be described by Gallup as ?thriving." They were also less likely than any other workers to have felt sad or angry in the past day, and the most likely to have the energy needed to be productive. Physicians are often exceptionally well-paid. According to the Medical Group Management Association, primary care physicians earned a median annual compensation of more than $200,000, while for those with medical specialties the figure exceeded $350,000.
2. Teacher
? Job types: High school, special education teacher, teacher assistants
? Well-being index score: 73.6
? Obesity: 79.4 percent
? Percent with health insurance: 95.7 percent
? Percent satisfied with job: 91.1 percent
Teachers had higher self-evaluations of their lives than workers in every other occupation beside physicians. Nearly 70 percent of teachers qualifying as ?thriving? based on their current and expected future quality of life. Teachers were also the most likely workers to report they smiled or laughed, experienced enjoyment or experienced happiness within the past day. Teachers surveyed also regularly practiced healthy behaviors. More than 64 percent ate at least five servings of fruits and vegetables at least four days a week, second only to nurses, and just under 6 percent smoked, less than only physicians. According to the BLS, median pay for ?education, training and library occupations" was just over $45,000 in 2010 -- higher than the median for all occupations.
3. Business Owners
? Job types: Contractor, store owner, entrepreneur
? Well-being index score: 73.4
? Obesity: 79.5 percent
? Percent with health insurance: 77.6 percent
? Percent satisfied with job: 93.3 percent
Business owners are more likely than any other class of workers to rate their work environment highly. Over 93 percent of business owners said they were satisfied with their job or the work they did, higher than any occupation except for physician. Additionally, nearly 89 percent of business owners reported their work environment was trusting and open -- by far the highest of any type of worker. According to the BLS, as of February there were almost 14.5 million self-employed workers, down from nearly 15.9 million five years prior.
24/7 Wall St.: Companies Paying the Least in Taxes
The Least Satisfied Professions
1. Transportation
? Job types: Bus drivers, flight attendants, air traffic controllers
? Well-being index score: 63.3
? Obesity: 62.9 percent
? Percent with health insurance: 77.0 percent
? Percent satisfied with job: 84.8 percent
Just over 80 percent of transportation employees believe that they use their strengths at work, lower than any other occupation except for clerical workers. Many transportation jobs, such as bus drivers and cab drivers, pay low wages, possibly contributing to a lower sense of well-being. Other positions in the industry pay quite well. For instance, air traffic controllers had a median pay of $108,040 in 2010, a pretty good haul considering that the position only needs an associate?s degree. However, the position involves a high amount of stress due to the intense concentration necessary and the nights and weekends involved.
2. Manufacturing or Production
? Job types: Assembly line workers, bakers, machine workers
? Well-being index score: 64.3
? Obesity: 70.4 percent
? Percent with health insurance: 78.8 percent
? Percent satisfied with job: 83.4 percent
Manufacturing and production employees -- such as factory workers, food preparation workers, garment or furniture manufacturers -- had lower ratings of their work environments than nearly all other occupations. They were less likely to feel satisfied in their job and among the least likely to be satisfied with how their supervisor treated them. Many of these jobs are low wages jobs. The median annual salaries of bakers and food processors were $23,450 and $23,950, respectively in 2010. The median 2010 salaries of assemblers, metal and plastic machine workers, and printing workers were all below the national median for all occupations. Manufacturing and production employees also ranked as the nation?s worst for healthy behavior due to high rates of smoking and low rates of exercise.
Installation and repair workers, such as linesmen, mechanics, as well as maintenance and repair workers, were less likely to practice healthy behaviors. They were among the least likely employees to regularly eat fruits and vegetables, and among the most likely to smoke. Additionally, these workers also provided lower self-evaluations of their current lives than all occupations except for transportation workers. Many of these positions require no more than a high school diploma alongside moderate or long-term on-the-job training and do not pay considerably more than the median pay of $33,840 for all occupations.
Click here to read the rest of 24/7 Wall St.'s The Most (and Least) Satisfied Professions
Lithium-ion battery technology topic of dozens of new scientific reports this weekPublic release date: 7-Apr-2013 [ | E-mail | Share ]
Contact: Michael Bernstein
m_bernstein@acs.org
504-670-4707 (New Orleans Press Center, April 5-10)
202-872-6042
Michael Woods
m_woods@acs.org
504-670-4707 (New Orleans Press Center, April 5-10)
202-872-6293
American Chemical Society
NEW ORLEANS, April 7, 2013 With lithium-ion batteries in the news for grounding the Boeing 787 Dreamliner fleet and as a fixture in many consumer electronics products li-ion technology is the topic of dozens of potentially newsworthy scientific reports that begin here today. The presentations are part of the 245th National Meeting & Exposition of the American Chemical Society, the world's largest scientific society.
Abstracts of some key reports scheduled for the meeting appear below.
###
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Abstracts
High efficiency low temperature recycling technology for lithium ion batteries
Yan Wang, Worcester Polytechnic Institute
Phone: 508-831-5453
Email: yanwang@wpi.edu
Lithium ion (Li ion) batteries are extensively used because of their high energy density, good cycle life, high capacity, etc. The rechargeable Li ion battery market was ~ $4.6 billion in 2006 and is expected to grow to more than $6.3 billion by 2012. Also lithium ion batteries are gradually being used for large applications, such as hybrid or electrical vehicles and grid systems. At present, Li ion batteries such as the ones used in cell phones and laptops are not widely recycled. We believe that such an open loop industrial cycle is not sustainable; it is our strong conviction that we must develop and establish viable Li ion battery recycling methodologies. In this project, we recycle Li ion batteries through low temperature chemical methods and active materials can be synthesized during recycling process; this will reduce energy usage, environmental damage, lead to economically viable processes, and strengthen our national security position.
Potential induced structural changes and solid electrolyte interphase (SEI) decomposition in Sn anodes for Li ion batteries
Hadi Tavassol, University of Illinois Urbana Champaign
Phone: 217-333-8720
Email: tavasso2@illinois.edu
We report measurements of electrochemical surface stress of thin film Sn electrodes for Li-ion battery anodes at potentials
In contrast, Sn surfaces exhibit significant changes in compressive and tensile surface stress even before Li insertion. Since these features occur in potential regions where there is no major interaction between Li and Sn, these features originate in changes in the Sn material itself. During the cathodic scan, an intense compressive feature at ca. 0.7 V vs. Li/Li+ is observed. A major tensile release at ca. 0.6 V vs. Li/Li+ follows this compressive feature. These features have a structural origin in a phase change in the Sn anode. This phase change impacts the ability of Sn and its alloys to serve as an anode material for a Li ion battery.
We also report the results of matrix assisted laser desorption (MALDI) time of flight (TOF) mass spectrometry (MS) analysis of Sn electrodes. In a mixture of ethylene carbonate and dimethyl carbonate, long chain oligomers are observed following the first cycle. These oligomers decompose in the subsequent cycles showing that Sn surfaces form an unstable SEI. This decomposition produces oligomerized species, which are different from those formed at the end of the first cycle. We discuss potential and solvent dependent oligomerization mechanisms and their effect on the mechanical properties of Sn electrodes.
Chemically induced stresses in Li ion battery electrodes
Brian W. Sheldon, Brown University
Phone: 401-863-2866
Email: Brian_Sheldon@brown.edu
Lithiation induced volume changes in battery electrode materials lead to a variety of chemo-mechanical phenomena. It is difficult to investigate these mechanisms directly in complex electrode microstructures that consist of powdered active components, conductive filler, and binders. Thin films provide an opportunity to more directly investigate fundamental processes, by combining in situ stress data with conventional in situ electrochemical measurements. Three examples that demonstrate this approach will be highlighted: (1) the formation of the solid-electrolyte interphase (SEI) layer on graphitic carbon films, where disruption of the near surface leads to stresses that impact the SEI stability; (2) the stress-induced response of interfaces in model Si-based nanocomposite structures, (3) the role of stress and oxygen non-stoichiometry on phase transformations in vanadium oxide films.
New low-temperature, non-flammable polyelectrolyte systems for lithium ion batteries
Joseph M DeSimone, University of North Carolina at Chapel Hill
Phone: 919-962-5468
Email: desimone@unc.edu
Renewable lithium-ion batteries are promising sustainable alternatives to non-renewable energy resources like petroleum. However, safety concerns, electrochemical stability, and narrow temperature range of operation remain persisting challenges that impede their prominence. In order to circumvent these shortcomings, we will describe herein a new class of lithium ion electrolytes composed of perfluoropolyethers (PFPE) and poly(ethylene oxide) (PEO) mixtures. These polymeric blends are amphiphilic, transparent, homogeneous and demonstrate the ability to solvate different lithium salts. The flammability, degree of crystallinity, ionic conductivity and electrochemical stability of these carbonate-free systems will be discussed.
Vanadium oxide mesocrystals: Synthesis, formation mechanism, and application in lithium-ion battery
Evan Uchaker, University of Washington
Phone: 206-543-2600
Email: uchaker@uw.edu
An additive and template free process was developed for the synthesis of mesocrystalline VO2(B) nanostars via the solvothermal reaction of oxalic acid and V2O5. Microscopy results demonstrate that the six-armed star architectures are composed of stacked nanosheets that are homoepitaxially oriented along the [100] crystallographic register with respect to one another. The mesocrystal formation mechanism is proposed to proceed through classical as well as non-classical crystallization processes and was possibly facilitated or promoted by the presence of a reducing/chelating agent. The product was tested as cathode for lithium-ion batteries and show good capacity at discharge rates ranging from 150-1500 mA g-1 and a cyclic stability of 195 mA h g-1 over fifty cycles. The exposed (100) facets lead to fast lithium intercalation, and the homoepitaxial stacking of nanosheets offers a strong inner-sheet binding force that leads to better accommodation of the strain induced during cycling.
High-performance lithium-ion battery anode based on core-shell heterostructure of silicon-coated vertically aligned carbon nanofibers
Jun Li, Kansas State University
Phone: 785-532-0955
Email: junli@ksu.edu
A high-performance hybrid lithium-ion anode material was developed using coaxially coated Si shells on vertically aligned carbon nanofiber (VACNF) cores. The bush-like VACNFs serve as conductive cores to effectively interface with Si shells for Li+ storage. The open core-shell nanowire structure allows the Si shells to freely expand/contract in the radial direction during Li+ insertion/extraction. A high specific capacity of 3000-3650 mAh(gSi)-1, comparable to the maximum value of amorphous Si, has been achieved. About 89% of capacity is retained after 100 charge-discharge cycles at C/1 rate. After long cycling, the electrode material becomes even more stable, showing the invariant Li+ storage capacity as the charge-discharge rate is increased by 20 times from C/10 to C/0.5 (or 2C). The ability to obtain high capacity at significantly improved power rates while maintaining the extraordinary cycle stability demonstrates that this novel structure could be a promising anode material for high-performance Li-ion batteries.
Used Li-ion batteries recycling: Lithium recovery for a new utilization
Richard Laucournet, CEA Grenoble
Phone: 33 438 781 178
Email: richard.laucournet@cea.fr
The French Alternative Energies and Atomic Energy Commission has been starting a key program on the development of Li-ion technologies for applications such as green transportation and stationary energy storage. Among them, the technologies based on LFP and LTO active materials are now transferring at industrial scale. In parallel, the recycling has to be considered for production scrap and batteries end of life.
In this domain, two main issues arise:
The European regulation fixes at 50% the minimal recycling rate,
The economical balance of current recycling processes is threatened by materials without Co, Ni or Mn.
A study has been initiated on the recycling of such materials by hydrometallurgy in order to maximize the value of main elements by reintroducing them in the new active materials synthesis. Lithium and Iron were recovered, separated and turned into phosphates or carbonates with high purity and high recovery rate.
Redox Shuttle Additives for High Voltage Lithium-Ion Battery Cathodes
Susan A. Odom, University of Kentucky
Phone: 404-805-1799
Email: susan.odom@uky.edu
Preventing overcharge in lithium-ion batteries is critical for extending battery lifetimes and preventing safety issues. When batteries connected in series have non-equivalent capacities, one or more batteries will become fully charged before the battery pack is completely charged, thus resulting in an overcharged state, which lead to irreversible reactions of the electrode and electrolyte. Redox shuttles can mitigate excess charge by acting as an internal shunt for excess current. We are developing new redox shuttles with the aim of increasing oxidation potentials for higher voltage cathodes. It is also critical to have long cycle lifetimes to ensure many overcharge cycles. We report new N-ethylphenothiazine derivatives as redox shuttle additives. The presentation will include synthesis of new derivatives, comparisons of oxidation potentials from cyclic voltammetry to energy levels obtained from DFT calculations, and battery cycling studies.
Non-flammable electrolytes for high performance lithium-ion batteries
Christopher Rhodes, Lynntech, Inc.
Phone: 979-764-2313
Email: chris.rhodes@lynntech.com
Rechargeable lithium-ion batteries with improved safety and high performance are needed for numerous applications including electric vehicles and consumer electronics. Current lithium-ion batteries utilize a flammable electrolyte which can combust and release highly toxic chemicals. Non-flammable electrolytes based on ionic liquids, phosphates, phosphonates, and other fire retardant additives have been developed, however, most non-flammable electrolytes developed to date result in decreased battery performance particularly under high rate and low temperature conditions. Compositions were developed to allow the electrolyte to be both non-flammable and provide high performance under wide temperature ranges and high rates. The electrolyte properties and electrochemical performance of cells containing the electrolyte were evaluated. Testing showed that electrolytes containing specific flame retardant additives and components provide batteries with significantly lower flammability and similar capacities, rates, cycle lives, and temperature ranges as batteries containing conventional flammable electrolytes.
Graphene-based flexible supercapacitors and lithium ion batteries
Hui-Ming Cheng, Institute of Metal Research, Chinese Academy of Sciences
Phone: 0086-24-2397-1611
Email: cheng@imr.ac.cn
Graphene has high specific surface area, good chemical stability, high electrical and thermal conductivity, and excellent flexibility. Therefore, graphene and its composite materials can be used as free-standing and binder-free electrodes for flexible energy storage devices.
First, flexible graphene/polyaniline paper was prepared by in situ anodic electropolymerization of polyaniline on a graphene membrane, and it shows a stable large electrochemical capacitance and excellent cyclibility. Second, we fabricated graphene-cellulose paper membranes which are used as freestanding and binder-free electrodes for flexible supercapacitors with good performance. Finally, we developed template-directed CVD to synthesize a three-dimensional interconnected graphene framework (GF). An anode and cathode were made by coating active materials on the GF to assemble a thin, lightweight and flexible lithium ion battery. The battery has high rate capability and capacity, and can be repeatedly bent down to
Silicon nanowire core aluminum shell coaxial nanocomposites for lithium ion battery anodes grown with and without a TiN interlayer
David Mitlin, University of Alberta
Phone: 780-492-1542
Email: dmitlin@ualberta.ca
We investigated the effect of aluminum coating layers and of the support growth substrates on the electrochemical performance of silicon nanowires (SiNWs) used as negative electrodes in lithium ion battery half-cells. Extensive TEM and SEM analysis was utilized to detail the cycling induced morphology changes in both the Al-SiNW nanocomposites and in the baseline SiNWs. We observed an improved cycling performance in the Si nanowires that were coated with 3 and 8 wt.% aluminum. After 50 cycles, both the bare and the 3 wt.% Al coated nanowires retained 2600 mAh/g capacity. However beyond 50 cycles, the coated nanowires showed higher capacity as well as better capacity retention with respect to the first cycle. Our hypothesis is that the nanoscale yet continuous electrochemically active aluminum shell places the Si nanowires in compression, reducing the magnitude of their cracking/disintegration and the subsequent loss of electrical contact with the electrode. We combined impedance spectroscopy with microscopy analysis to demonstrate how the Al coating affects the solid electrolyte interface (SEI). A similar thickness alumina (Al2O3) coating, grown via atomic layer deposition (ALD), was shown not to be as effective in reducing the long-term capacity loss. We demonstrate that an electrically conducting TiN barrier layer present between the nanowires and the underlying stainless steel current collector leads to a higher specific capacity during cycling and a significantly improved coulombic efficiency. Using TiN the irreversible capacity loss was only 6.9% from the initial 3581 mAh/g, while the while the first discharge (lithiation) capacity loss was only 4%. This is one of the best combinations reported in literature.
Materials challenges and opportunities of lithium-ion batteries
Arumugam Manthiram, University of Texas at Austin
Phone: 512-471-1791
Email: rmanth@mail.utexas.edu
Lithium-ion batteries have revolutionized the portable electronics market, but their adoption for transportation and stationary electrical energy storage applications is hampered by high cost and safety concerns. The success of lithium-ion technology for these applications relies heavily on the development of low-cost, safe cathode and anode materials with high energy and power along with long cycle life. After providing an overview of the pros and cons of the existing cathode and anode materials, this presentation will focus on high-capacity, high-voltage layered and spinel oxide cathodes as well as nano-engineered alloy anodes. With the oxide cathodes, the importance of surface structure and chemistry to realize a robust electrode-electrolyte interface and superior electrochemical performance will be focused. With the alloy anodes, the importance of nanoarchitectures to avoid particle growth and realize long cycle life will be discussed.
Silicon and Germanium nanowires for next generation high capacity lithium ion batteries
Brian A Korgel, University of Texas at Austin
Phone: 512-471-5633
Email: korgel@che.utexas.edu
Lithium (Li)-ion batteries have the highest energy and power density of any available rechargeable battery technology and they are widely used to power portable electronics. Still, Li-ion batteries are needed with lower cost, lighter weight, higher energy density, and better performance at fast charge/discharge rates. The most demanding Li-ion batteries applications of in battery-powered electric vehicles and large-scale (or grid) energy storage require unprecedented enhancements in energy and power density. One way to increase the energy density of a Li-ion battery is to replace the graphite anode with silicon (Si) or germanium (Ge). Si and Ge have significantly higher lithium storage capacities than graphite (3,579 mA h g-1 and 1,384 mA h g-1 compared to 373 mA h g-1). Si and Ge, however, undergo massive volume expansions when lithiatedby about 280%. Nanowires are being explored for Li-ion batteries because they can more or less tolerate these volume changes without degradation. Battery performance, however, relies on all of the constituents of the anode, including electrolyte and binder formulations. Seeds used to grow the nanowires can also influence the battery performance. Here, we present battery results using large quantities of Si and Ge nanowires grown by solution-based methods. The highest performance Si nanowires have been grown using tin seeds, which is also electrochemically active, and Ge nanowires have exhibited the best rate capability with capacities near the theoretical capacity due to its reasonably high electrical conductivity and fast Li diffusion.
Lithium-ion batteries: Ageing processes and surface/interface phenomena
Remi Dedryvere, University of Pau
Phone: 33 5 59 40 75 97
Email: remi.dedryvere@univ-pau.fr
Lithium-ion batteries are the well-established power source of portable electronic devices. Research efforts are now mainly motivated by the quest for improved energy storage systems for renewable energies and urban transportation. Future Li-ion battery applications such as electric vehicles require higher energy or power densities. Other applications require a good electrochemical behavior at high temperatures.
The reactivity at electrode/electrolyte interfaces is a very important issue. Common Li-ion batteries can work only because a passivation layer is formed at the surface of graphite that prevents this electrode from side reactions towards electrolyte. The use of new nanosized electrode materials, or operating at unusual temperatures, increases the importance of these electrode/electrolyte interface issues that directly impact the safety and the life span of batteries. In this presentation I will show some of the latest results obtained in the study of ageing processes in Li-ion batteries by X-ray Photoelectron Spectroscopy (XPS).
Lithium single-ion conducting polymers with unusual high-voltage stabilities for battery applications
Ryan L. Weber, University of Wisconsin Madison
Phone: 330-414-6897
Email: rweber@chem.wisc.edu
Polymeric lithium single-ion conductors (PLSICs), in which mobile Li-ions are associated with a polyanionic backbone, mitigate problems with electrolyte polarization in Li-ion batteries. We have synthesized an electrochemically stable PLSIC by acyclic diene metathesis (ADMET) polymerization of a diolefin monomer containing a lithium bis(malonato)borate functionality. Electrochemical studies of this polymer reveal moderate lithium conductivity and an unusually wide electrochemical window (0.05-8.0 V vs. Li/Li+) due to the formation of a stable solid-electrolyte interphase (SEI) layer.
Nanosheets of layered transition metal dichalcogenides for lithium-ion batteries
Timothy R Pope, University of Georgia
Phone: 470-214-7834
Email: timpope@uga.edu
Layered transition metal dichalcogenides, MX2, where M is a transition metal from groups 4 to 6 and X is S, Se, or Te, have potential as high discharge capacity materials in lithium-ion batteries. In these materials, individual layers of MX2 are held together by van der Waals forces, which permits the intercalation of ions or small molecules, as well as separation into mono-or multilayer nanomaterials. To date, studies with MoS2 nanoplatelets (>10 nm thickness) have shown that this MX2 material does not performed as well as expected in lithium-ion battery applications. We propose that the higher surface area of MX2 nanosheets (
Conversion reactions for lithium ion battery cathodes
Jason Graetz, Brookhaven National Laboratory
Phone: 631-344-3242
Email: graetz@alumni.caltech.edu
Materials that undergo a conversion reaction with lithium (e.g., metal fluorides) often accommodate more than one Li atom per transition-metal, and are promising candidates for high-capacity electrodes for lithium batteries. However, little is known about the mechanisms involved in the conversion process, the origins of the large polarization during electrochemical cycling, and why some materials are reversible (FeF2) while others are not (CuF2). A better understanding of the conversion reaction mechanism requires tracking the local phase nucleation and evolution with lithiation, which is extremely challenging due to the complexity of the reaction and presence of multiple phases within nano-scale domains. This work provides new insights into the inter- and intra-particle Li transport and kinetics of lithium conversion reactions, and may help to pave the way to develop high-energy conversion electrodes for lithium-ion batteries.
Fundamental microstructural designing concepts for high capacity and long cycle life of anode materials based on carbon and silicon for lithium ion battery
Chongmin Wang, Pacific Northwest National Laboratory
Phone: 509-371-6268
Email: Chongmin.wang@pnnl.gov
For lithium ion battery, a range of materials has a high theoretical capacity, while in reality, this type of materials cannot be used directly due to a fast capacity fading. It is believed that the capacity fading and short cycle life of the battery using this type of materials are directly related to the overall large volume expansion and anisotropic accommodation of the volume change. Carbon is a commonly used conductor additive in the lithium electrode materials and it has a range of tailorable structures, ranging from nanofiber, graphene, and particles. Therefore, it is a natural approach to rationally design a composite materials based on Si and carbon. Due to their nanoscale dimensions, the lithiation induced volume expansion and shape change can be accommodated, therefore, reducing the chance of the failure of the battery. In this presentation, we review some of the fundamental designing concepts and associated challenges for tailoring composite materials based on Si and carbon as anode materials with high capacity and long cycle life.
Nanostructured electrodes for lithium ion batteries
Guozhong Cao, University of Washington
Phone: 206-616-9084
Email: gzcao@u.washington.edu
Lithium-ion batteries store electrical energy in the form of chemical potential like primary batteries; however, the charge-discharge process in lithium-ion batteries is more complex as it involves not only Faradaic reactions at the interface between electrodes and electrolyte, but also is accompanied with mass and charge transport and volume change of the electrodes that commonly possess low electrical conductivity. Electrodes away from thermodynamic equilibrium include nanostructures with high surface energy, poor-crystalline materials, and materials with significant surface or bulk defects. Such materials are in higher energy state and, thus, easier for phase transfer and nucleation; such materials also have less closely packed structure, permitting faster mass transport and accommodating more lithium-ions as well as tolerating more volume change. This presentation will take vanadium pentoxide and lithium titanate as two model materials to illustrate the influences of doping, surface defects and carbon coating, and nanostructures on the lithium-ion intercalation properties.
Fused aromatic heterocycles for overcharge protection in lithium-ion batteries
Corrine N. F. Elliott, University of Kentucky
Phone: 859-257-9545
Email: Corrine.Elliott@stu.fayette.kyschools.us
Derivatives of the aromatic molecule phenothiazine have been used in batteries due to their ability to form the corresponding radical with minimal degradation, allowing them to redirect excess energy and prevent overcharge. This project aimed to find more efficient molecules for use as overcharge protectors in batteries. Specifically, oxidation potential, determined via cyclic voltammetry, was used to identify derivatives that could be used for higher end-of-charge potential cathodes, and the reversibility of the oxidation was examined. Derivatives of phenothiazine were synthesized in which alternate groups were substituted for the hydrogen molecules at junctions two and seven, as were molecules with 2,7-cyano groups but alternate base compounds. More broadly, the x-ray crystal structure was determined for each molecule to determine relative planarity in the hopes of discovering a relationship between planarity and efficiency. This experiment provides a basis for determining the accuracy of planarity as an indicator of a compound's effectiveness as an overcharge protector; results may also suggest the most efficient base molecules to serve as said additives.
Ultrathin coating of Al2O3 on negative electrode for lithium ion batteries
Minho Yang, Korea Advanced Institute of Science and Technology
Phone: 82-42-350-1152
Email: minho.yang@kaist.ac.kr
Next generation lithium ion batteries have required the high energy/power density and long cycling stability for powering transportation and grid systems. The silicon has been expected as a suitable negative electrode to apply these areas due to high theoretical energy capacity (4200 mAh/g). However, the silicon suffers from huge volume expansion, which cause loss of electrical contact among active materials and finally capacity fading. Here, we demonstrated the ultrathin coating of Al2O3 on patterned silicon wafer (p-Si) as a negative electrode for lithium ion batteries by surface sol-gel method. Al2O3 coated p-Si was characterized by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The TEM and XPS data revealed that the p-Si was conformably coated with 5 nm of Al2O3. The electrochemical behavior and cycle performance were examined by cyclic voltammetry, electrochemical impedance spectroscopy, and battery cycler.
Bicyclic-borate synthesis for use in lithium ion batteries
Ryan J Kowalski, Case Western Reserve University
Phone: 414-899-5845
Email: rjk151@case.edu
Bicyclic-borate complexes have been synthesized for use as an alternative anion for lithium ion batteries in hopes that they will provide insight into more flame retardant types of ions, or FRIons. This synthesis has been done through azeotropic distillations and solvent-free methods utilizing boronic acids. The current bicyclic compounds being produced were inspired by creating derivatives of lithium bis(oxalato) borate, also known as LiBOB.
Carbon cross-linked Si/SiC nanosphere as advanced anode of lithium-ion batteries
Junhong Chen, University of Wisconsin-Milwaukee
Phone: 414-229-2615
Email: jhchen@uwm.edu
Silicon-based materials have been demonstrated as promising alternative anode materials with a specific capacity as high as around 4,200 mAh g-1 at a relative low discharge potential; however, the conventional Si-based anode suffers from rapid degradation in capacity due to its poor electrical conductivity and huge volume change during charging-discharging processes. We herein report a rational design and controllable route to fabricate carbon cross-linked Si/SiC nanospheres, in which the carbon not only functions as the network building block but also acts as a conducting film. The preparation was realized through thermal reduction of cross-linked SiO2@C using magnesium powders as a reducing agent. The hierarchical Si/SiC/C nanostructures exhibited a capacitance of around 860 mAh g-1 after cycling for 100 cycles with capacity retention of above 65%. The as-developed method is envisaged to pave a promising way to prepare high performance Si-based anode materials for lithium-ion batteries.
Stability and reactivity of redox shuttle additives for lithium-ion batteries
Selin Ergun, University of Kentucky
Phone: 859-257-9545
Email: selin.ergun@uky.edu
Derivatives of fused heteroaromatic molecules have been studied as electrolyte additives, also called redox shuttles, for overcharge protection in lithium-ion batteries with varying degrees of success. These additives fail as they decompose in their radical cation state, reacting with other shuttle molecules, electrodes, or electrolyte. Our goal is to study new redox shuttles that can undergo extended overcharge cycles. Therefore we are studying the stability of the radical cations formed in situ through spectroscopic techniques and performing DFT calculations simultaneously in order to observe a trend between experimental and computational results. The lack of extended cycles is not only due to stability of radical cations, but can also originate from possible reactions that can occur in battery conditionsintramolecular or intermolecular. Here we report results on radical cation stability and reactivity for possible redox shuttles in order to understand the possible mechanisms for the shuttle reaction in batteries.
DFT design and study of lithium-ion battery electrolytes and anode
Jyh-Chiang Jiang, National Taiwan University of Science and Technology
Phone: 288627376653
Email: jcjiang@mail.ntust.edu.tw
The modification of edges in both graphene and graphite can significantly alter the electronic properties as well as the lithium diffusion mechanism. Our finding illustrate the importance of controlling the edges of these carbonaceous materials with atomic precision in order to take full advantage of their potential for high density applications in lithium ion batteries.
With regard to the electrolyte, the thermodynamic and kinetic data for the oxidative decomposition of PC show that the major oxidative decomposition products are independent of the type of lithium salt. Furthermore, the most possible components of the film formed on the cathode surface are polycarbonate, acetone, diketone, 2-(ethan-1-ylium-1-yl)-4-methyl-1,3-dioxolan-4-ylium and CO2. Similarly the major products which are responsible for the formation of protective SEI film when ES is used as an additive are Li2SO3, (CH2OSO2Li)2, CH3CH(OSO2Li)CH2OCO2Li and ROSO2Li. While, the products from the termination reactions of the primary radical of PS would build up an effective solid electrolyte interphase.
Investigating the voltage fading mechanism in Li1.2Co0.1Mn0.55Ni0.15O2 lithium-ion battery cathode by in situ x-ray diffraction studies
Debasish Mohanty, Oak Ridge National Laboratory
Phone: 865-576-0813
Email: mohantyd@ornl.gov
In this study, in situ x-ray diffraction (XRD) technique was implemented to investigate the voltage fading pathways in lithium-rich Li1.2Co0.1Mn0.55Ni0.15O2 cathode in a lithium-ion battery. A custom designed coin-cell with Kapton film window of ~ 13mm in diameter opening was fabricated for in situ XRD experiment. The in situ XRD was collected during electrochemical charge/discharge process performed in 2.4-4.8 V voltage window at 10 mA/g rate in fist cycle and after subsequent cycles (16 and 36). The collected in situ XRD patterns were simulated and lattice parameters were calculated to correlate with the electrochemical profile. The results show increase in c-lattice parameter during initial charging up to 4.4 V and subsequently decreases beyond 4.4 V. The a-lattice parameter remains constant at the first cycle plateau region. After 16(36) cycles, (440) cubic spinel reflections were observed which indicate a layer to spinel-like phase transformation and believed to suppress the voltage profile.
Nanodiamond-derived carbon nano-onions as negative electrode materials for lithium-ion batteries
Mahendra K Sreeramoju, University of Kentucky
Phone: 859-257-5393
Email: mksree2@uky.edu
Nanodiamond-derived carbon nano-onions (N-CNOs) were prepared by annealing of nanodiamonds at 1650 C under flow of helium. The morphology and structure of N-CNOs were investigated by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction, Raman spectroscopy and BET nitrogen adsorption. Due to their smaller size and number of surface defects, they exhibit higher surface area (520 m2/g) and mesoporosity. Due to their smaller size, high surface area and number of surface defects, these N-CNOs exhibit high capacity and stable cycling performance as anode materials for lithium-ion batteries at slower (C/10) and higher (C) charge-discharge rates compared with that of mesocarbon microbead (MCMB) graphite particles.
High energy density silicon anodes for lithium-ion batteries: Combining hollow nanospheres with conductive polymer binder
Yan Yao, University of Houston
Phone: 713-743-4432
Email: yyao4@uh.edu
The alloying reaction of Si with lithium causes significant volume expansion during lithiation process and lead to the fracture of Si particles because of huge lithiation-induced mechanical stress. Various approaches with different focus, such as nanoengieering Si anode structures, stabilizing solid-electrolyte interphases between Si and organic electrolyte, and synthesizing new polymer binders to accommodate the volume change, have been shown successfully improving the energy density and cycle life, bringing Si anodes one step closer into practical Li-ion batteries. In this preprint, we show that both the active hollow nanospheres Si anode structure and the inactive conductive polymer binder have significant impact on the anode cycling performance. Combining the hollow nanospheres with conductive polymer binder, long cycle life Si anode is demonstrated at high energy density.
Porous structured silicon for lithium-ion battery anode
Chongwu Zhou, University of Southern California
Phone: 213-740-4708
Email: chongwuz@usc.edu
Silicon is a promising anode material for lithium ion battery, because of its highest theoretical capacity (4200 mAh/g). However, intrinsic drawbacks of silicon, e.g. pulverization due to repeating volume change in cycling, and low lithium ion diffusivity in silicon, set hindrances for silicon to be used in high power-density battery. Here we find porous structured silicon a promising anode material for lithium ion battery. Theoretical study shows the pores can help to stabilize the structure by means of providing additional spaces to accommodate large volume change during cycling, and therefore release the stress and strain inside silicon. In addition, the large surface area that accessible to electrolyte helps to shorten the diffusion length for lithium ions, which enables fast charge/discharge. Experimentally, we have employed porous silicon nanowires as a prototype to show the advantages of using porous structured silicon as lithium-ion battery anode. By combining with alginate binder, the porous silicon nanowire shows capacity larger than 1000 mAh/g after 2000 cycles at current rate of 4 A/g. Beyond that, we have developed a scalable and cost-efficient method to produce nano and micron porous silicon particles, which shows decent battery performance.
New directions in rechargeable lithium-ion batteries: Lessons from in situ electron microscopy
Reza Shahbazian-Yassar, Michigan Technological University
Phone: 906-487-3581
Email: reza@mtu.edu
Nanostructured anode materials have received considerable attention in energy storage devices due to the enhanced electrochemical reactions at the surface and their unique electrical and mechanical properties. Silicon and titanate nanostructures are promising anode materials because of their energy capacity and safer performance for Li-ion batteries. One of the hurdles in developing better and long lasting batteries is the lack of scientific knowledge on the electrochemical reactions that happen inside a battery under charging and discharging conditions. Using real-time microscopy at atomic resolutions should shed light into some of the fundamental questions in this field. This presentation focuses on the in-situ observation of lithiation and delithiation in Si nanorods and TiO2 nanotubes. The electrochemical testing of these low dimensional structures were conducted inside a transmission electron microscope equipped with a novel in-situ electrical probing holder. The intercalation of Li-ions in Si nanorods was monitored during charging and the fracture of nanorods was quantified in terms of size. In addition, the intercalation of crystalline anatase and amorphous TiO2 was studied and their fracture events were monitored in real time.
Quino(triazene)s: A new class of organic cathode materials for the lithium ion battery
Charles Daniel Varnado, The University of Texas at Austin
Phone: 512-471-1419
Email: cdvarnado@cm.utexas.edu
There has been much interest in the development of organic cathode materials for lithium ion batteries as a green alternative to the expensive lithium cobalt oxide. Previously, our group has reported a novel class of compounds derived from the reaction of quino(imidazolylidene)s and a variety of azidoarenes. In this presentation, we report the synthesis and characterization of a series of quino(triazene)s as cathodes for lithium ion batteries. Furthermore, we describe their solid state structure, electrochemistry, electrochromic properties, and battery performance.
First principles atomistic modeling of surface and interfacial effects in lithium ion battery materials
Maria K Y Chan, Argonne National Laboratory
Phone: 630-252-4811
Email: mchan@anl.gov
Surfaces and interfaces play an important role in the performance of lithium ion batteries, including such effects as surface orientation-dependent lithiation, surface chemistry-dependent lithiation capacity, and the formation of the solid-electrolyte interphase (SEI). Computational modeling, especially first principles atomistic approaches, provides significant insight into these surface and interfacial effects. A significant challenge in such modeling is the construction of atomistic models to accurate describe the complexity of the surfaces and interfaces.
In this talk, I will discuss using a variety of first principles approaches to tackle the challenge of building accurate atomistic models of surfaces and interfaces in lithium ion battery materials. I will describe how such approaches are used to study: orientation-dependence, and the lack thereof, of lithiation in silicon and germanium; the effects of surface chemistry on the lithiation of silicon; the deposition of lithium on gold; and the formation of SEI on silicon.
Enhanced lithium ion battery energy density with carbon nanotube current collectors
Matthew J Ganter, Rochester Institute of Technology
Phone: 315-778-1465
Email: mjg9074@rit.edu
Traditional battery electrodes consist of composites coated onto high density, inactive metal current collectors which can limit battery energy density. Conventional methods of increasing energy density include the use of higher capacity materials. However, when electrodes are paired in a full battery, only a small increase in energy density is realized due to the capacity limited cathode compared to novel anode materials. A more significant increase in energy density can be realized by reducing or eliminating the mass of the current collector. This work investigates the replacement of metal current collectors with carbon nanotube (CNT) papers using traditional composites to reduce electrode mass and increase energy density. The results show that CNTs can replace metal current collectors on both the anode and cathode and achieve expected specific capacities. The electrode specific capacity, including current collector mass, increased up to 28% for the cathode and 188% for the anode using CNTs.
Surface-disordered hydrogenated TiO2 nanocrystals for lithium ion battery
Xiaobo Chen, University of Missouri
Phone: 816-235-6420
Email: chenxiaobo@umkc.edu
TiO2, mainly known for photocatalysis, has also been studied as a safer anode material for lithium ion batteries compared to graphite, while with the limited lithium ion diffusion within the host and the structural distortion during lithium insertion/extraction. Here, we demonstrate that a thin layer of hydrogenated surface disorder on the crystalline TiO2 electrode may induce better electrochemical energy storage performance, better charge/discharge rate performance, larger capacity and longer stability. The reasons for these improvements are proposed in terms of the facilitation of easier lithium ion transport within the disordered layer and the less structural distortion during the lithium insertion/extraction process.
Next generation polymer nanocomposite electrolytes for lithium ion batteries
Haleh Ardebili, University of Houston
Phone: 713-743-4500
Email: hardebili@uh.edu
Polymer electrolytes offer many advantages compared to liquid electrolytes used in lithium ion batteries, including safety, stability and thin film manufacturability. Nanoscale fillers can enhance Li ion conductivity as well as the mechanical properties of polymer electrolytes. In this study, we investigate the role of nanofillers in enhancing ion conductivity including experimental results as well as insights from our continuum-level model and molecular dynamics (MD) simulations. Novel nanoscale fillers including hybrid clay-carbon nanotubes (CNTs) for next generation polymer electrolytes will also be discussed. We show that CNTs grown and insulated within clay layers can work as effective hybrid 3D nanofillers and improve Li ion conductivity of PEO electrolyte by almost two orders of magnitude with significant enhancement in tensile strength. Ion conductivity enhancement can be attributed to the high surface density of the hybrid fillers and the strong interactions between the CNT's negative electron cloud and positive lithium ions.
Increasing redox shuttle oxidation potentials to match high voltage cathodes in lithium-ion batteries
Susan Odom, University of Kentucky
Phone: 859-257-3294
Email: susan.odom@uky.edu
Electrolyte additives called redox shuttles can protect batteries in series from experiencing overcharge, a condition in which one or more fully charged cells continue to receive applied current. Derivatives based on 1,4-dimethoxybenzene, N-alkylphenothiazine, and TEMPO cores have been reported as superior additives for overcharge protection. Eventually these electrolyte additives fail, presumably due to decomposition of their radical cation forms. Increased electron deficiency makes radical cations more susceptible to nucleophilic attack, which may result in reactions with electrolyte components. Few examples of stable redox shuttles for high voltage cathodes have been reported, presumably due to their high reactivity. Our work focuses on improving the stability of redox shuttles for high voltage cathodes. We have synthesized a variety of carbazole, diphenylamine, phenothiazine, and phenoxazine derivatives containing electron-withdrawing groups. This study focuses on the electrochemical analysis of the new derivatives and the stability of their radical cation forms.
Multiscale multiphysics lithium-ion battery model with multidomain modular framework
Gi-Heon Kim, National Renewable Energy Laboratory
Phone: 303-275-4437
Email: gi-heon.kim@nrel.gov
Lithium-ion batteries (LIBs) powering recent wave of personal ubiquitous electronics are also believed to be a key enabler of electrification of vehicle powertrain on the path toward sustainable transportation future. Over the past several years, National Renewable Energy Laboratory (NREL) has developed the Multi-Scale Multi-Domain (MSMD) model framework, which is an expandable platform and a generic modularized flexible framework resolving interactions among multiple physics occurring in varied length and time scales in LIB[1]. NREL has continued to enhance the functionality of the framework and to develop constituent models in the context of the MSMD framework responding to U.S. Department of Energy's CAEBAT program objectives. This talk will introduce recent advancements in NREL's LIB modeling research in regards of scale-bridging, multi-physics integration, and numerical scheme developments.
Solvothermal synthesis, growth mechanism, and performance of LiFePO4 nanorods used as a cathode material in lithium ion batteries
David Kisailus, University of California-Riverside
Phone: 951-827-2260
Email: david@engr.ucr.edu
We report the use of water-triethylene glycol (TEG) as a solvent to synthesize LiFePO4 (LFP) nanorods with uniform size. TEG, a reducing agent in the reaction, promotes the formation of LiFePO4. Crystal phase and growth behavior were monitored by powder X-ray diffraction (XRD), synchrotron X-ray Diffraction, as well as transmission electron microscopy (TEM), while particles morphologies were investigated with scanning electron microscope (SEM). Three crystal growth mechanisms during the synthesis were interpreted based on the time study of the samples. Initially, the nucleation of LFP (20nm thick sheets) occurred accompanying with the formation of Fe3(PO4)28H2O (vivianite). This metastable phase evolved into spindle-like olivine LiFePO4 through oriented attachment (OA) of LFP primary nanosheets. With the increasing reaction time, the pH decreased with the concurrent formation of LiFePO4. The dissolution-recrystallization process, i.e. Ostwald ripening (OR), results in evenly distributed
LiFePO4 nanorods due to the increased solubility of LiFePO4. The mechanism (from nanosheet to spindle to rod) revealed by this study will help develop guidelines to control the size and morphological features of LFP more precisely.
Safe collection and high value recycling of li-ion batteries
Legal obligations for producers and distributors of batteries in Germany
Collection and recycling of batteries in Germany
Risks and safety issues
Potential risks in end-of-live chain
First nationwide take-back system for industrial Li batteries in Europe
Logistic solutions: collection, packaging, transport of Li batteries
Recycling strategy for Li batteries
Market volumes
Li batteries: applications and end-of-life volumes
Material contents
Content of valuable materials in Li batteries
Recycling technologies
Thermo metallurgical technologies
Hydro metallurgical technologies
Mechanical chemical technologies
Mechanical technologies
Recycling products and markets
Economical valuation
Conclusions for European recycling strategy
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Lithium-ion battery technology topic of dozens of new scientific reports this weekPublic release date: 7-Apr-2013 [ | E-mail | Share ]
Contact: Michael Bernstein
m_bernstein@acs.org
504-670-4707 (New Orleans Press Center, April 5-10)
202-872-6042
Michael Woods
m_woods@acs.org
504-670-4707 (New Orleans Press Center, April 5-10)
202-872-6293
American Chemical Society
NEW ORLEANS, April 7, 2013 With lithium-ion batteries in the news for grounding the Boeing 787 Dreamliner fleet and as a fixture in many consumer electronics products li-ion technology is the topic of dozens of potentially newsworthy scientific reports that begin here today. The presentations are part of the 245th National Meeting & Exposition of the American Chemical Society, the world's largest scientific society.
Abstracts of some key reports scheduled for the meeting appear below.
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Abstracts
High efficiency low temperature recycling technology for lithium ion batteries
Yan Wang, Worcester Polytechnic Institute
Phone: 508-831-5453
Email: yanwang@wpi.edu
Lithium ion (Li ion) batteries are extensively used because of their high energy density, good cycle life, high capacity, etc. The rechargeable Li ion battery market was ~ $4.6 billion in 2006 and is expected to grow to more than $6.3 billion by 2012. Also lithium ion batteries are gradually being used for large applications, such as hybrid or electrical vehicles and grid systems. At present, Li ion batteries such as the ones used in cell phones and laptops are not widely recycled. We believe that such an open loop industrial cycle is not sustainable; it is our strong conviction that we must develop and establish viable Li ion battery recycling methodologies. In this project, we recycle Li ion batteries through low temperature chemical methods and active materials can be synthesized during recycling process; this will reduce energy usage, environmental damage, lead to economically viable processes, and strengthen our national security position.
Potential induced structural changes and solid electrolyte interphase (SEI) decomposition in Sn anodes for Li ion batteries
Hadi Tavassol, University of Illinois Urbana Champaign
Phone: 217-333-8720
Email: tavasso2@illinois.edu
We report measurements of electrochemical surface stress of thin film Sn electrodes for Li-ion battery anodes at potentials
In contrast, Sn surfaces exhibit significant changes in compressive and tensile surface stress even before Li insertion. Since these features occur in potential regions where there is no major interaction between Li and Sn, these features originate in changes in the Sn material itself. During the cathodic scan, an intense compressive feature at ca. 0.7 V vs. Li/Li+ is observed. A major tensile release at ca. 0.6 V vs. Li/Li+ follows this compressive feature. These features have a structural origin in a phase change in the Sn anode. This phase change impacts the ability of Sn and its alloys to serve as an anode material for a Li ion battery.
We also report the results of matrix assisted laser desorption (MALDI) time of flight (TOF) mass spectrometry (MS) analysis of Sn electrodes. In a mixture of ethylene carbonate and dimethyl carbonate, long chain oligomers are observed following the first cycle. These oligomers decompose in the subsequent cycles showing that Sn surfaces form an unstable SEI. This decomposition produces oligomerized species, which are different from those formed at the end of the first cycle. We discuss potential and solvent dependent oligomerization mechanisms and their effect on the mechanical properties of Sn electrodes.
Chemically induced stresses in Li ion battery electrodes
Brian W. Sheldon, Brown University
Phone: 401-863-2866
Email: Brian_Sheldon@brown.edu
Lithiation induced volume changes in battery electrode materials lead to a variety of chemo-mechanical phenomena. It is difficult to investigate these mechanisms directly in complex electrode microstructures that consist of powdered active components, conductive filler, and binders. Thin films provide an opportunity to more directly investigate fundamental processes, by combining in situ stress data with conventional in situ electrochemical measurements. Three examples that demonstrate this approach will be highlighted: (1) the formation of the solid-electrolyte interphase (SEI) layer on graphitic carbon films, where disruption of the near surface leads to stresses that impact the SEI stability; (2) the stress-induced response of interfaces in model Si-based nanocomposite structures, (3) the role of stress and oxygen non-stoichiometry on phase transformations in vanadium oxide films.
New low-temperature, non-flammable polyelectrolyte systems for lithium ion batteries
Joseph M DeSimone, University of North Carolina at Chapel Hill
Phone: 919-962-5468
Email: desimone@unc.edu
Renewable lithium-ion batteries are promising sustainable alternatives to non-renewable energy resources like petroleum. However, safety concerns, electrochemical stability, and narrow temperature range of operation remain persisting challenges that impede their prominence. In order to circumvent these shortcomings, we will describe herein a new class of lithium ion electrolytes composed of perfluoropolyethers (PFPE) and poly(ethylene oxide) (PEO) mixtures. These polymeric blends are amphiphilic, transparent, homogeneous and demonstrate the ability to solvate different lithium salts. The flammability, degree of crystallinity, ionic conductivity and electrochemical stability of these carbonate-free systems will be discussed.
Vanadium oxide mesocrystals: Synthesis, formation mechanism, and application in lithium-ion battery
Evan Uchaker, University of Washington
Phone: 206-543-2600
Email: uchaker@uw.edu
An additive and template free process was developed for the synthesis of mesocrystalline VO2(B) nanostars via the solvothermal reaction of oxalic acid and V2O5. Microscopy results demonstrate that the six-armed star architectures are composed of stacked nanosheets that are homoepitaxially oriented along the [100] crystallographic register with respect to one another. The mesocrystal formation mechanism is proposed to proceed through classical as well as non-classical crystallization processes and was possibly facilitated or promoted by the presence of a reducing/chelating agent. The product was tested as cathode for lithium-ion batteries and show good capacity at discharge rates ranging from 150-1500 mA g-1 and a cyclic stability of 195 mA h g-1 over fifty cycles. The exposed (100) facets lead to fast lithium intercalation, and the homoepitaxial stacking of nanosheets offers a strong inner-sheet binding force that leads to better accommodation of the strain induced during cycling.
High-performance lithium-ion battery anode based on core-shell heterostructure of silicon-coated vertically aligned carbon nanofibers
Jun Li, Kansas State University
Phone: 785-532-0955
Email: junli@ksu.edu
A high-performance hybrid lithium-ion anode material was developed using coaxially coated Si shells on vertically aligned carbon nanofiber (VACNF) cores. The bush-like VACNFs serve as conductive cores to effectively interface with Si shells for Li+ storage. The open core-shell nanowire structure allows the Si shells to freely expand/contract in the radial direction during Li+ insertion/extraction. A high specific capacity of 3000-3650 mAh(gSi)-1, comparable to the maximum value of amorphous Si, has been achieved. About 89% of capacity is retained after 100 charge-discharge cycles at C/1 rate. After long cycling, the electrode material becomes even more stable, showing the invariant Li+ storage capacity as the charge-discharge rate is increased by 20 times from C/10 to C/0.5 (or 2C). The ability to obtain high capacity at significantly improved power rates while maintaining the extraordinary cycle stability demonstrates that this novel structure could be a promising anode material for high-performance Li-ion batteries.
Used Li-ion batteries recycling: Lithium recovery for a new utilization
Richard Laucournet, CEA Grenoble
Phone: 33 438 781 178
Email: richard.laucournet@cea.fr
The French Alternative Energies and Atomic Energy Commission has been starting a key program on the development of Li-ion technologies for applications such as green transportation and stationary energy storage. Among them, the technologies based on LFP and LTO active materials are now transferring at industrial scale. In parallel, the recycling has to be considered for production scrap and batteries end of life.
In this domain, two main issues arise:
The European regulation fixes at 50% the minimal recycling rate,
The economical balance of current recycling processes is threatened by materials without Co, Ni or Mn.
A study has been initiated on the recycling of such materials by hydrometallurgy in order to maximize the value of main elements by reintroducing them in the new active materials synthesis. Lithium and Iron were recovered, separated and turned into phosphates or carbonates with high purity and hig
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Public release date: 7-Apr-2013
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