Interfacial modification for high-power solid-state lithium batteries

Interfaces between LiCoO 2 and sulfide solid electrolytes were modified in order to enhance the high-rate capability of solid-state lithium batteries. Thin films of oxide solid electrolytes, Li 4Ti 5O 12, LiNbO 3, and LiTaO 3, were interposed at the interfaces as buffer layers. Changes in the high-rate performance upon heat treatment revealed that the buffer layer should be formed at low temperature to avoid thermal diffusion of the elements. Buffer layers of LiNbO 3 and LiTaO 3 can be formed at low temperature for the interfacial modification, because they show high ionic conduction in their amorphous states, and so are more effective than Li 4Ti 5O 12 for high-power densities.