Facet-Dependent Mechanical-Electrochemical Coupling of Lithium Metal Anodes in All-Solid-State Batteries

Abstract Interfacial failure driven by mechano-electrochemical coupling between lithium (Li) metal anodes and solid-state electrolytes (SSEs) remains a critical bottleneck restricting the application of all-solid-state lithium metal batteries. Current studies predominantly focus on polycrystalline Li, yet the effect of crystallographic anisotropy on interfacial stability remains unexplored. Herein, the impact of the intrinsic crystallographic anisotropy of Li facets was investigated for their critical mechanical properties and electrochemical stripping performance under varied stack pressures and current densities. Li(110) possesses the lowest yield strength (0.5 MPa) and highest power-law creep exponent (6.95) among the three typical facets, exhibiting stronger stress sensitivity than Li(200) and Li(211). Under identical stack pressure, the accelerated creep rate of Li(110) better accommodates current-induced interfacial Li flux. This mechano-electrochemical matching correlates with a 34−68% improvement in stripping capacity and sustains an extended duration of conformal contact before failure. This work verifies crystallographic engineering as a viable approach to optimize Li anode stability and boost battery performance.