Solid-State Batteries and Interface Issues

All-solid-state lithium batteries (ASSLBs) based on solid-state electrolytes have become the most sought-after candidates for next-generation electrochemical storage systems due to their high safety and energy density, simple packaging, and wide operable temperature range. In the past few decades, all-solid-state batteries have developed rapidly, and remarkable achievements have been made. However, their widespread applications are inhibited by many critical challenges. The core of a solid-state battery is a solid-state electrolyte. Therefore, the performances of all-solid-state batteries are directly related to the fundamental properties of solid-state electrolyte materials and the condition of the electrode/electrolyte interfaces. In this chapter, we provide and discuss the typical three types of solid-state batteries based on the chemical composition of solid electrolytes, including oxide-based solid-state batteries, sulfide-based solid-state batteries, and polymer-based solid-state batteries. Here, the ion conductivities and ion-transport mechanisms of solid-state electrolytes are reviewed. Then, we focus on the compatibilities of electrode/electrolyte interfaces. In particular, the interface physics (contact and wettability) and interface chemistry (passivation layer, ionic transport, dendrite growth) are paid attention to and discussed, as well as the characterization methods and strategies to solve the above concerns. At the end of each section, based on the current challenges and opportunities of all-solid-state batteries, possible research directions, and future perspectives are proposed.