A cathode configured for a solid-state battery includes a body having grains of inorganic material sintered to one another, wherein the grains comprise lithium. A thickness of the body is from 3 μm to 100 μm. The first major surface and the second major surface have an unpolished granular profile such that the profile includes grains protruding outward from the respective major surface with a height of at least 25 nm and no more than 150 μm relative to recessed portions of the respective major surface at boundaries between the respective grains.