Morphogenic electrochemical solid-state interfaces

Solid-state batteries (SSBs) with lithium (Li) metal anodes have emerged as promising candidates for next-generation energy storage technologies, offering higher energy density and improved safety over conventional Li-ion systems. However, achieving a stable Li metal-solid electrolyte (SE) interface remains a persistent challenge, as nonuniform electrodeposition can lead to morphological instabilities, filament growth, and eventual short circuits. In this work, we demonstrate mechanics-driven morphogenesis of the Li-SE interface during plating at zero external pressure, where chemo-mechanical coupling drives self-organized patterns analogous to growth processes observed in biological systems. The change in reaction kinetics due to the mechanical overpotential alters the free energy landscape, lowering the deposition barrier at peaks and accelerating filament growth. In contrast, the stress gradients give rise to an additional ionic flux toward valleys, resulting in uniform morphology and reaction homogenization. By investigating the interplay between mechanics-dependent kinetics and stress-driven transport, we show how different electrochemical, thermodynamic, and mechanical descriptors can together bring a stability shift from unstable to stable evolution. Under optimized conditions, these mechanisms result in a self-regulating interface morphology and suppress the onset of filament growth. The insights from this study provide a mechanistic basis for designing stable Li-SE interfaces, offering guidance for SE selection and interface engineering in SSBs.