Oxide-based all-solid-state batteries using aerosol deposition

Oxide-based all-solid-state batteries (OX-SSBs) have been expected as next generation rechargeable batteries. In the OX-SSBs, charge transfer reaction occurs at electrode-solid electrolyte interface and then both of them must adhere well with smaller interfacial ion transfer resistance. Although various kinds of electrodes and solid electrolytes have been proposed, most of them are composed of different elements and concentrations, and, in addition, they have different thermal stability. Thus, sintering process frequently provide mutual diffusion layer around the interface, which often induce highly resistive interface and then degrade the performance of the OXSSBs. To overcome this problem, we have focused on aerosol deposition (AD), a room temperature ceramics densification technology, to develop electrode-solid electrolyte interface at lower temperature. By applying the AD process, we have developed 4 V- and 5 V-class electrode-solid electrolyte composite electrodes and investigated their electrochemical properties as OX-SSBs at 100°C. Moreover, the AD can realize inverted-stack Li-free thin-film OX-SSBs, where crystalline LiCoO2 electrode is formed on amorphous LiPON film. Our recent works on OX-SSBs using the AD will be introduced in this review.