Challenges and Strategies of Low-Pressure All-Solid-State Batteries

All-solid-state batteries (ASSBs) are regarded as promising next-generation energy storage technology owing to their inherent safety and high theoretical energy density. However, achieving and maintaining solid-solid electronic and ionic contact in ASSBs generally requires high-pressure fabrication and high-pressure operation, posing substantial challenges for large-scale production and application. In recent years, significant efforts are made to address these pressure-related challenges. In this review, the impact of pressure on ASSBs is explored. First, the categories, origins, and challenges associated with pressure in ASSBs are outlined. Second, an overview of recent advancements in addressing pressure-related issues in ASSBs is provided, focusing on electrode materials and their interfaces with various solid-state electrolytes (SSEs). Third, advanced characterizations and simulations employed to unravel the intricate electrochemical-mechanical interactions in ASSBs are examined. Finally, existing strategies and the insights on achieving low-stack-pressure ASSBs are presented.