Interfaces in Oxide‐Based Li Metal Batteries*

The introduction of new, safe, and reliable solid–electrolyte chemistries and technologies can potentially overcome the challenges facing their liquid counterparts while widening the breadth of possible applications. Through tech-historic evolution and rationally analyzing the transition from liquid-based Li-ion batteries (LIBs) to all-solid-state Li-metal batteries (ASSLBs), we introduce a roadmap for the development of a successful oxide-based ASSLB focusing on interfacial challenges, while accounting for five parameters: energy density, power density, long-term stability, processing, and safety. Taking a strategic approach, this review discusses the overriding challenges associated with the pairing of the solid electrolyte with oxide-based cathodes and Li-metal anode, leading to the limited performance of solid-state batteries are extensively addressed and possible strategies to mitigate these issues are presented. Finally, future perspectives, guidelines, and selective interface engineering strategies toward the resolution of these challenges are analyzed and discussed as outlined.