Recent advances in garnet-based electrolytes for solid-state lithium metal batteries: interfacial challenges and engineering strategies

Solid-state lithium metal batteries (SSLMBs) are recognized as the most efficient and promising energy storage devices due to their enhanced safety and high energy density. As a key component in solid-state lithium metal batteries, solid-state electrolytes (SSEs) are critical for the development of batteries. Garnet-type SSEs have been employed as the most critical component of inorganic electrolytes and fillers for composite electrolytes. To date, significant research on garnet-based electrolytes has been carried out and numerous breakthrough results have been achieved. However, poor interfacial contacts between garnet-based electrolytes and electrodes still lead to Li dendrite growth and unsatisfactory electrochemical performance of batteries. Herein, recent developments of the interfaces for garnet based SSLMBs, including the strategies of garnet types and composite electrolytes as well as Li metal anode stabilizations are presented. Moreover, interfacial engineering strategies between electrolytes and cathodes are also discussed. Meanwhile, advanced techniques and electrochemical approaches for interfacial characterization are also introduced. This work provides insights into the interfacial engineering of garnet-based electrolytes, contributing to the understanding of interfaces in solid-state batteries.