(Invited) Oxide-Based All-Solid-State Batteries Prepared By Aerosol Deposition

Abstract

Oxide-based all-solid-state batteries (OX-SSBs) have been expected as next generation rechargeable batteries. Although various kinds of high Li+ conductive solid electrolytes have been prepared such as Li7La3Zr2O12 (LLZ), NASICON-structured Li1.3Al0.3Ti2(PO4)3 (LATP), LiTaPO4 etc, there are serious problems to develop low-resistive positive electrode/high Li+ conductive solid electrolyte interface. Because these high Li+ conductive solid electrolytes are crystallized at 800-1000 ℃, high temperature sintering is common way to combine them with conventional crystalline insertion electrode materials (LiCoO2 (LCO), LiNi1/3Co1/3Mn1/3O2 (NCM111) etc). However, both electrodes and solid electrolytes are composed of different elements with different concentrations, such high temperature sintering process frequently provide mutual diffusion region around the interface in addition to structural degradation and then seriously impede the interfacial resistance. Thus, one strategy to prevent those side reactions will be to apply low temperature sintering or densification process. We have focused on aerosol deposition, AD, a room temperature ceramic coating process. AD can realize quick speed and wide area ceramic coating and has been estimated as a cost-effective process technology for oxide-based energy conversion devices. AD make it possible to prepare electrode-solid electrolyte composite electrodes at room temperature and LiCoO2 film electrode on LiPON film. In addition, AD enables us to investigate the effects of annealing temperature on the interfacial resistances and then limiting temperature for sintering.In this presentation, our recent works on Ox-SSBs using the AD will be introduced 1) 4V- and 5V-class bulk-type Ox-SSBs, 2) effects of annealing temperature on interfacial resistivity, an example of LCO-LATP system to determine limiting temperature for sintering.