ACT/SGER: Improving the Lifetimes of Batteries: NMR Studies of Structure and SEI Formation

Suny At Stony Brook, Stony Brook NY

Investigators

Abstract

Two related exploratory projects will be performed, which will provide information concerning the mechanisms of cell failure and will aid in the development of new, improved electrode materials for use in lithium-ion batteries: (i) The preparation and investigation of nano-sized LiCoO2 cathode materials, and (ii) the development of nuclear magnetic resonance (NMR) methods to study thin-film electrodes such as amorphous silicon. Through these projects, we will explore correlations between size, morphology and structure, and the effect of these parameters on electrochemical performance. Systems where the solid electrolyte interphase (SEI) is a much higher fraction of the bulk will be prepared allowing the SEI to be readily investigated by NMR spectroscopy, the primary characterization method used in this research program. The SEI is the film that forms on the electrode particles on battery assembly and grows on cycling, and is a source of capacity loss (and eventually cell failure). Longer lasting, lighter and more compact electrochemical power sources are required to power many of the devices used by the intelligence community. Lithium-ion batteries represent one such power source. In order to improve these batteries, both an increased understanding of the battery failure mechanisms and the development of new, higher capacity electrodes are required. The Approaches to Combat Terrorism Program in the Directorate for Mathematics and Physical Sciences supports new concepts in basic research and workforce development with the potential to contribute to national security.