We next analyze the reactivity of the argyrodite electrolyte, Li 6 PS 5 Cl with the chloride catholytes listed in Table . Li 6 PS 5 Cl has a high Li-ion conductivity in the range of 1-10 mS cm -1 at room temperature, and can be processed using a simple cold-pressing method, making it a viable SE for ASSBs. Our results suggest that in the SI. This could be due to the common (3+) oxidation state of the transition metal in the chloride catholytes containing In, Y, or Al. In the case of LGPS, its reaction with Li 3 InCl 6 is redox in nature, as revealed by the apparent changes in the oxidation states of the P (+5 in LGPS to +4 in In 2 (PS 3 ) 3 ) and S (-2 in LGPS to -1 in P 2 S 7 ) species.