Lithium Ion batteries are used in most, if not all, electronic devices. Li-ion batteries can be made up of a single battery unit or made up of several units called cells.
Lithium ion batteries are the most popular type of batteries for electronics and even in electric cars because of its long battery life and performance. This is due to to their energy density slow loss of charge when not in use.
The American Chemical Society as part of the 245th National Meeting & Exposition of the American Chemical Society had several presentations on the study and resulting developments in lithium ion battery technology. Various scientific and educational organizations presented their studies during the event.
Abstracts of these studies are enumerated below and in separate articles (see related links).
Lithium-ion battery technology topic of dozens of new scientific reports this week
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 are listed below and posted in separate articles.
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 163,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
Video: Lithium-ion batteries: How do they work?
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 less than 2.0 V vs. Li/Li+. For most anodes, mechanical properties are dominated and controlled by Li-host interactions. Graphite, Si, and a Au model system exhibit compressive stress resulting from Li insertion. Calculations support these experimental results. Anodes experience tensile stress resulting from Li removal. This tensile stress may create cracks, and cause capacity loss.
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 less than 5 mm without failure and degradation of its electrochemical performance.
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 lithiated—by 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 (<10 nm thickness), which can be achieved by complete exfoliation, would allow more extensive interactions between lithium ions and the active MX2 material, and thus better battery capacity performance. We present electrode fabrication and coin cell test results for MoS2, TaSe2, WSe2, NbSe2, TiS2 and TiSe2.
Lithium ion batteries are the most popular type of batteries for electronics and even in electric cars because of its long battery life and performance. This is due to to their energy density slow loss of charge when not in use.
The American Chemical Society as part of the 245th National Meeting & Exposition of the American Chemical Society had several presentations on the study and resulting developments in lithium ion battery technology. Various scientific and educational organizations presented their studies during the event.
Abstracts of these studies are enumerated below and in separate articles (see related links).
Lithium-ion battery technology topic of dozens of new scientific reports this week
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 are listed below and posted in separate articles.
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 163,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
Video: Lithium-ion batteries: How do they work?
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 less than 2.0 V vs. Li/Li+. For most anodes, mechanical properties are dominated and controlled by Li-host interactions. Graphite, Si, and a Au model system exhibit compressive stress resulting from Li insertion. Calculations support these experimental results. Anodes experience tensile stress resulting from Li removal. This tensile stress may create cracks, and cause capacity loss.
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 less than 5 mm without failure and degradation of its electrochemical performance.
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 lithiated—by 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 (<10 nm thickness), which can be achieved by complete exfoliation, would allow more extensive interactions between lithium ions and the active MX2 material, and thus better battery capacity performance. We present electrode fabrication and coin cell test results for MoS2, TaSe2, WSe2, NbSe2, TiS2 and TiSe2.
RELATED LINKS
American Chemical Society
Studying Lithium Transport and Kinetics To Develop High Energy Conversion Electrodes for Li-Ion Batteries
Silicon and Carbon Composite Material In Lithium Ion Batteries for High Capacity and Long Cycle Life
Studying Lithium Ion Intercalation Properties Using Nanostructures, Vanadium Pentoxide and Lithium Titanate
Ultrathin Coating of Aluminum Oxide As Negative Electrode for Lithium Ion Batteries
Flame Retardant Ions (FRIons) As Alternative Anion For Lithium Ion Batteries
University of Wisconsin-Milwaukee Research on Using Silicon as Alternative Anode Materials
University of Kentucky Reports on Heteroaromatic Molecules (Redox Shuttle) as Electrolyte Additives in Lithium Ion Batteries
National Taiwan University of Science and Technology Presents Properties of Graphene and Graphite as Materials for Lithium Ion Batteries
Oak Ridge National Laboratory Uses In Situ X-Ray Diffraction (XRD) in Studying Voltage Fading Pathways in Li-Ion Batteries
Nanodiamond-derived carbon nano-onions (N-CNOs) As Material for Lithium Ion Batteries
University of Houston Presents Improving Energy Density and Cycle of Life of Silicon Anodes with Nanotechnology
University of Southern California Presents Research on Porous Structured Silicon as Anode Material In Li-Ion Batteries
Michigan Technological University Research on Nanostructured Anode Materials in Lithium Ion Batteries
University of Texas at Austin Abstract on Organic Cathode Materials on Lithium Ion Batteries
Argonne National Laboratory Presents Research on Surface and Interface Performance on Lithium Ion Batteries
Rochester Institute of Technology Abstract on Replacing Metal Current Collectors with Carbon Nanotubes
University of Missouri Abstract on Using Titanium Dioxide (TiO2) on Lithium Ion Batteries
University of Houston Abstract on Using Polymer Electrolytes on Lithium Ion Batteries
University of Kentucky Abstract on Protecting Batteries From Overcharge Using Redox Shuttles
National Renewable Energy Laboratory Abstract on Multi-Scale Multi-Domain (MSMD) model framework and Lithium Ion Batteries
UC-Riverside Abstract On Using LiFePO4 Nanorods As A Cathode Lithium Ion Batteries
Stiftung GRS Batterien Abstract on Collection and Recycling of Lithium Ion Batteries
Silicon Anodes For Three Times More Efficient Lithium Ion Batteries Being Developed
Piezoelectricity Allows Pacemaker To Operate Without A Battery
Advances in Lithium Ion Batteries: 1 Week Power on a 15 Minute Charge
Rechargeable Battery That Can Be Painted On Any Surface Developed
Renewable Battery Cathode Produced from Pulp and Paper Waste
Nanobiodevice Captures Cancer Cells in Bloodstream
Bio Nanotech Transient Electronics For Medical and Commercial Use Dissolve After Completing Its Task
Damaged and Impure Carbon Nanotubes Provide Attractive, Low-cost Alternative Catalysts In Fuel Cells.
Using Graphene And Nanotechnology To Build A Faster Edison Battery
