 Li-6 plus XM-XAs1, XS5i, M equals psi, SM, has been proposed as a new type of sulfide solid-state electrolyte for use in all solid-state batteries. This material shows excellent stability in humid air environments and can be used in conjunction with lead oxide positive electrodes and Li in negative electrodes. Testing of this material showed that it can provide good cycling performance, power density, and energy density when used in combination with these components. This article was authored by Pusher and Lu, Yuxia, Quacheng Sun, and others.