(415e) Salt-Ceramic Composite Electrolytes for Lithium Metal Batteries

Lithium metal based all solid state batteries are promising candidates for next generation energy storage system due to their high energy densities. A key challenge for lithium metal batteries is the development of a solid electrolyte because they have good chemical and thermal stability, robust mechanical strength, and are able to stop dendrite growth of Li anodes. However, present processing method of solid electrolytes requires high temperature to sinter ceramic powder, which limits opportunities for integration soft materials and leads to high processing costs. Here, we developed salt-ceramic composite electrolytes through a cold sintering process that utilizes a small amount of solvent and uniaxial pressure to sinter ceramics at low temperatures (~130 ^oC). By synthesizing salt-LATP composite electrolytes with various lithium salts, conductivities at room temperature close to 8 × 10^-4 S/cm were achieved; this is one of the highest value obtained from LATP electrolytes so far. In addition, we also found out that a lithium salt was able to improve the sinterability of LATP, resulting in increased relative density of composite electrolytes. We believe that our approach of salt-ceramic composites through cold sintering may make an impact in a variety of fields, including solid electrolytes, composite cathodes, and tough or responsive structural materials.