How Stacking Pressure and Temperature Regulate Lithium Plating and Stripping in Solid-State Lithium Metal Batteries

The stable integration of solid-state electrolyte (SSE) with lithium metal anode is critical for constructing high-energy-density solid-state lithium metal batteries (SSLMBs). However, the uncontrolled lithium filament growth and continuous dead lithium accumulation still severely restrict practical applications. Stacking pressure and operating temperature significantly influence ion transport, interfacial reactions, and stress responses, but the dynamic regulation mechanisms for lithium deposition and stripping remain poorly understood. Therefore, we develop an electrochemical, mechanical, and phase-field coupled model to characterize lithium plating and stripping in SSLMBs. We reveal the influence mechanisms of stacking pressure and operating temperature on the morphological evolution of lithium filaments and the formation/distribution of dead lithium and clarify the effect of internal short-circuit risk and irreversible capacity loss. The phase diagrams of stacking pressure, temperature, normalized lithium filament height, and irreversible capacity loss rate are constructed, elucidating the regulatory mechanisms of stacking pressure and operating temperature on internal short-circuit risk and cyclic capacity loss. The lithium deposition morphology and dead lithium formation exhibit a strong dependency, emphasizing the critical importance of favorable deposition morphology for cycling performance. This study provides theoretical guidance for external physical field (stacking pressure and temperature) regulation strategies to enhance the safety and cycling stability of solid-state lithium metal batteries.