Professor John Newman has been selected to receive the Acheson Award of The Electrochemical Society. This prestigious award will be given to Professor Newman at the next meeting of the Society, to be held in Las
Vegas during the week of October 10-15, 2010. Professor Newman’s greatest contribution to the “objects, purposes or activities of The Electrochemical Society” (i.e., the definition of the Acheson Award, as spelled out below)” has been his seminal approach to the analysis and design of electrochemical systems.
Archives for May 2010
Low Cost Method for Improving Battery Capacity
Lithium Nitride for Prelithiating Anodes to Reduce Capacity Losses in Li-Ion Batteries
The Richardson Lab has developed a new method for prelithiating anodes to compensate for the first-cycle capacity loss associated with conventional lithium-ion batteries. The prelithiated anodes supply lithium for the irreversible reactions that occur upon initial charging, such as decomposition of the electrolyte to form a solid electrolyte interphase (SEI) layer on the anode. Since lithium ions from the cathode are not consumed in SEI formation, the battery capacity is retained.
The Fate of Ethylene Carbonate in Lithium-Ion Battery Electrolytes
A Reactive Molecular Dynamics Simulation Study of Single-Electron Reduction Pathways
The Smith Group, at the University of Utah, has identified reaction products of the single-electron reduction of ethylene carbonate (EC), an important component in lithium-ion battery electrolytes. Reactive force field (ReaxFF) simulations were used to discover the fate of EC, which provides insight into the structure of the solid electrolyte interphase (SEI) – a thin film covering carbon anodes that limits the charge/discharge rate. Reactive force fields allow for the making/breaking of chemical bonds during classical molecular dynamics simulations. Because electronic degrees of freedom are treated in a simplified manner, these reactive molecular dynamics (RMD) simulations allow for the study of chemical reactions in much larger collections of molecules over much longer times than can be studied using ab initio methods.
Iron Doping Improves Cathode Stability
Passivation of Spinel Cathode Surface through Self-Segregation of Iron
The Manthiram Lab has developed an iron-doped, high-voltage cathode based on lithium nickel manganese oxide that results in extended cyclability and improved electrochemical performance. The cathode’s spinel structure enables 3-D Li+-ion diffusion and direct metal-metal interaction across the shared octahedral edges, which supports high power capability for HEV and PHEV applications at high operating voltages (> 4.3 V vs. Li/Li+). The iron-enrichment on the cathode surface prevents surface-electrolyte instability at these high operating voltages.
High Capacity and Faster Charging Batteries
New Material for High-Voltage Anodes in Lithium-Ion Batteries
The Goodenough Lab has synthesized a new anode material that can operate at voltages between 1.0 and 1.6 V vs. Li+/Li0. This TiNb2O7 (TNO) anode joins the ranks of the spinel lithium titanate (Li4Ti5O12) in being an anode material that operates within the window of thermodynamic stability for an organic-liquid carbonate electrolyte. Existing lithium-ion batteries have carbon anodes that operate at voltages below this window of stability, thereby resulting in decomposition of the electrolyte and formation of a thin passivating film on the anode surface. This solid electrolyte interphase (SEI) layer traps Li+ ions, causing the battery to irreversibly lose capacity on the first charge; it also limits the charge/discharge rate. Since the TNO anode does not form an SEI layer, it does not rob capacity from the cathode and is capable of a fast battery charge.
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