Advanced Energy Research and Technology Center (AERTC)

Lithium Batteries for High-Power Applications

PI: Clare Grey

New applications such as hybrid electric vehicles, power backup and power tools, require rechargeable batteries that combine high energy density with high charge and discharge rate capability. The current generation of lithium-ion batteries, while meeting many of the criteria required for lap-tops and other portable electronics, are too slow to charge and discharge, and are associated with safety issues.

My group is engaged on a joint synthesis and characterization program, aimed at understanding how electrode materials (anodes and cathodes) function, why they fail, and how to make better materials. In particular we use solid-state lithium NMR (nuclear magnetic resonance) to track the Li ions as they move through the lattices.

Our current DOE-supported work focuses on the cathode material Li(NiMn)oS02. This material is of particular interest, because it is free of cobalt, unlike the commercial Li-ion battery, which uses LiC002 as the cathode. Cobalt is undesirable both from a toxicity and cost standpoint. Our joint research program with our collaborator at MIT, Prof. Gerbrand Ceder, has lead to an improved cathode material with much higher discharge and charge rates. The work was featured this week in the journal Science (17 February 2006: Vol. 311, pp. 977 - 980) (DOE, Office of FreedomCAR)

In a related program supported by an NSF Approaches to Combating Terrorism
Grant, we synthesize and characterize nanoparticles of LiC002, Li(NiMn)Q.S02 and related materials. The smalier nanoparticles are expected to show much higher rate capabilities, and may be suitable for HEV applications.

Our NSF-DMR program work is more exploratory and high risk. Here, we are looking at a variety of novel and potential electrode materials, which include oxysulfides, fluorides and oxynitrides. Novel strategies are required if batteries with much higher capacities are to be found. (NSF)