(Invited) Optimization of Carbonate Electrolytes for Lithium Metal Anodes

Abstract

A solid electrolyte interphase (SEI) is generated on the anode of lithium ion batteries during the first few charging cycles. While the SEI generated for LiPF6/carbonate based electrolytes is stable on graphite anodes, the stability of the SEI is poor for LiPF6/carbonate based electrolytes with lithium metal anodes. However, modification of the carbonate based electrolytes via incorporation of alternative salts and/or electrolyte additives significantly improves the stability of the SEI and the cycle life of lithium metal anodes. Investigations of the SEI structure have been conducted via a combination of XPS, IR-ATR, SEM, and TEM. Mechanisms for the generation of the complicated mixture of products are presented along with the differences in the SEI structure and function.