Thin-film Li3InCl6 electrolyte prepared by solution casting method for all-solid-state batteries

All-solid-state batteries (ASSBs) with solid-state electrolytes (SSEs) have become a hot research topic in recent years due to their high energy density and safety. However, most research is limited to the use of electrode and electrolyte powders pressed together for testing purposes, and it is impossible to achieve the goal of mass production by manufacturing complete batteries only via compression. Such a method might need extremely high pressure to obtain a fully dense system composed of both electrodes separated by the electrolyte and the largest the battery surface the highest the pressure demanded. Therefore, how to achieve mass production of SSEs while maintaining quality control is the focus of current research. In this work, we selected Li3InCl6 (LIC) as a solid-state electrolyte added with a small amount of ethyl cellulose as the binder. A wet method was developed accordingly using acetonitrile as solvent to fabricate thin LIC composite film SSE (LIC-ACE) directly on filter membrane deposition. The prepared SSEs showed the following characteristics: easy to peel off from the deposition support while maintaining structural integrity, and a high ionic conductivity of 0.76 mS cm−1 at room temperature. The structure, porosity and other properties were determined by SEM, XRD, and BET characterization. Finally, it can withstand more than 1000 h cycles without short circuit in symmetrical LiLi cell test and shows good electrochemical performance in the ASSBs test.