Exploring Electrolyte Corrosion and Compatibility Across Lithium-Ion and Lithium-Metal Batteries

Developing next-generation electric vehicle (EV) batteries remains challenging regarding improving energy density, cycle life, and safety. Efforts are required to understand the materials' failure mechanisms quantitatively and develop new battery chemistry that breaks the energy density bottleneck. In this presentation, I will first talk about a systematic re-evaluation of the low-concentration ether-based electrolyte (LCEE), which is a promising, low-cost electrolyte system for lithium metal batteries (LMBs) but has long been believed to have “inferior” anodic stability. We identify the true failure mechanism of this electrolyte to be various electrochemical corrosion reactions with different working electrodes, while the intrinsic anodic stability window of LCEE is above 4.5 V, a value feasible for practical LMB operation. We also provide and verify design rationales to mitigate electrode corrosion and thus improve the full-cell performance of LMBs under realistic conditions. I will then introduce our recent work in designing electrolytes that are compatible with both graphite and lithium metal, enabling controlled lithium metal plating on graphite to realize hybrid lithium-ion/lithium-metal batteries with improved energy density (> 300 Wh/kg) and cycle life (> 1000 cycles) at fast charging conditions (up to 4C).