Progress in Forming Thin-Film Solid Electrolytes Based on Li7La3Zr2O12 by Tape Casting

Abstract

All-solid-state batteries are in great demand worldwide. Particular attention is paid to the development of materials and the design of these batteries. Solid electrolytes have lower total conductivity compared to liquid electrolytes, so it is assumed that the transition to thin-film electrolytes can significantly reduce the internal resistance of the cell. Solid electrolytes of the garnet family based on Li7La3Zr2O12 (LLZ) are considered as promising ceramic membranes for such power sources. In the presented review, different methods for film formation of LLZ and their features are discussed. The tape casting method is considered in more detail as a promising approach for the formation of thin films of LLZ. The slurry components and heat treatment conditions for the formation of solid electrolyte films with thicknesses ranging from 10 to 500 μm and high values of conductivity (10–3–10–4 S · cm–1 at room temperature) are analyzed. Thus, the tape casting method can be used to obtain films with lithium-ion conductivity and relative density values comparable to those of bulk ceramic samples. However, the problem of organizing the electrode | solid electrolyte interface and the design of all-solid-state batteries remains very relevant for their development.