Resolving the mechanism of lithium anode decay and recovery during rest
Rechargeable Li-metal batteries (LMBs) have the potential to more than double the specific energy of the state-of-the-art rechargeable Li-ion batteries, making LMBs a prime candidate for next-generation high-energy battery technology. However, LMB's high-capacity loss per cycle hinders its widespread commercial adoption. Two major capacity depleting byproducts contribute to LMB's performance decay during cycling: 1) the solid electrolyte interphase (SEI) derived from the reduction of electrolyte on Li metal and 2) isolated Li (i-Li) which is metallic Li that has become electrically disconnected from the Cu current collector. Unfortunately, byproduct generation has been found to further increase when LMB cells are rested in the charged state, leading to additional cycle performance degradation. This dissertation aims to better understand the mechanisms driving capacity loss during rest and present strategies to mitigate and recover byproducts. The following chapters will cover 1) dynamics and stability of SEI during rest, 2) how discharged state resting can be used advantageously to promote recovery of lost capacity in LMBs, and 3) the effect spatially heterogeneous Li deposition has on capacity loss during charged state resting. These insights emphasize the marked impact rest, cycling strategies and deposition uniformity have on LMB capacity loss as well as highlight pathways to promote better cycle performance
論文、學位論文, English, 2024
[Stanford University], [Stanford, California], 2024