A method for making a solid state cathode comprises the following steps: forming an alkali-free first solution comprising at least one transition metal and at least two ligands; spraying this solution onto a substrate that is heated to about 100 to 400° C. to form a first solid film containing the transition metal(s) on the substrate; forming a second solution comprising at least one alkali metal, at least one transition metal, and at least two ligands; spraying the second solution onto the first solid film on the substrate that is heated to about 100 to 400° C. to form a second solid film containing the alkali metal and at least one transition metal; and, heating to about 300 to 1000° C. in a selected atmosphere to react the first and second films to form a homogeneous cathode film. The cathode may be incorporated into a lithium or sodium ion battery.