A thin film lithium-ion battery unit includes a positive current collecting substrate, a positive electrode active material layer on an inner surface of the positive current collecting substrate, a negative current collecting substrate, a negative electrode active material layer on an inner surface of the negative current collecting substrate, a separator between the positive electrode active material layer and the negative electrode active material layer, and electrolyte retained at least in the separator. The positive electrode active material layer, the separator and the negative electrode active material layer constitute a laminated electric core. An outer conductive frame is spaced apart from the positive current collecting substrate and encompasses the positive current collecting substrate.