This disclosure provides systems, methods, and apparatus related to an all-solid-state battery including a solid electrolyte. In one aspect, a device includes a first layer of an ionically conducting oxide, a second layer of the ionically conducting oxide disposed on the first layer, and an anode disposed on the second layer of the ionically conducting oxide. The first layer defines through pores having a tortuosity of about 1. The first layer includes transition metal oxide particles and an ionically conducting solid disposed in the through pores. The transition metal oxide particles are a cathode. The first layer and the ionically conducting solid are an electrolyte. The second layer does not define any through pores. The second layer is a separator.