Optimization of interfacial contacts in all-solid-state lithium-metal batteries under pressure and temperature modulation and its effect on cycling performance

All-solid-state lithium metal batteries (ASSLIBs) are emerging as promising candidates for next-generation energy storage devices due to their high energy density and safety. However, poor interfacial contact between electrodes and solid-state electrolytes severely limits their performance. This study investigates the effects of pressure and temperature on the interfacial contact coefficient and battery performance in a lithium metal cathode/LiPON electrolyte/LCO anode system using a multi-physics field coupling model integrated with Persson's contact mechanics theory. Results show that a high contact coefficient reduces interfacial impedance, suppresses lithium dendrite formation, and achieves a capacity retention rate of 92 % after 500 cycles. In contrast, poor contact leads to rapid capacity degradation and accelerates solid electrolyte interface (SEI) film thickening. Increasing the temperature to 20 °C reduces the potential drop by 30 %, while high pressure (70 MPa) enhances the lithium concentration dynamics. This study elucidates the synergistic effects of interfacial contact, pressure, and temperature, thereby providing a theoretical foundation for the interface design of solid-state batteries.