Recent Advancements in Interface between Cathode and Garnet Solid Electrolyte for All Solid State Li-ion Batteries

Abstract

All-solid-state lithium battery (ASSLB) with inorganic solid state electrolytes is one of promising candidates for electric vehicles and large-scale smart grids for storage of alternative energy resources due to their benefits in safety, energy density, operable temperature range, and longer cycle life. As the key component in ASSLB, inorganic lithium-ion-based solid-state electrolytes (SSEs), especially the garnet-type solid electrolytes that own ionic conductivities in the order of 10-3 S•cm-1 at room temperature and are relative safe vs. Li metal, have obvious advantages in ASSLB. However, interfacial instability and their poor solid-solid contact between garnet and cathode result in high interfacial resistance, low efficiency, and poor cycle performance. Based on these understandings and analyses of interface characteristics and issues, this work presents a brief review on modification of interface, covering composite cathode, composite electrolyte, interface engineering, and interface layer.Some approaches of improving interface wettability and future research directions of ASSLB are given as well, which endeavor to realize the practical applications of ASSLB.