Batteries and methods of forming the same include an anode structure, a cathode structure, and a conductive overcoat. The anode structure includes an anode substrate, an anode formed on the anode substrate, and an anode conductive liner that is in contact with the anode. The cathode structure includes a cathode substrate, a cathode formed on the cathode substrate, and a cathode conductive liner that is in contact with the cathode. The conductive overcoat is formed over the anode structure and the cathode structure to seal a cavity formed by the anode structure and the cathode structure. At least one of the anode substrate and the cathode substrate is pierced by through vias that are in contact with the respective anode conductive liner or cathode conductive liner.