The dead lithium formation under mechano-electrochemical coupling in lithium metal batteries

Abstract

Lithium metal is one of the most promising anode materials for next-generation high-energy-density rechargeable batteries. A fundamental mechanism understanding of the dead lithium formation under the interplay of electrochemistry and mechanics in lithium metal batteries is strongly considered. Herein, we proposed a mechano-electrochemical phase-field model to describe the lithium stripping process and quantify the dead lithium formation under stress. In particular, the rupture of solid electrolyte interphase and the shift of equilibrium potential caused by stress are coupled into stripping kinetics. The impact of external pressure on dead lithium formation with various electrolyte properties and initial electrodeposited morphologies is revealed. The overlooked detrimental effect of external pressure on Li stripping affords fresh insights into cell configuration and pressure management, which is critical for practical applications of lithium metal batteries.