Abstract: A method of fabricating a flexible battery comprises forming a first substrate on a first release liner, forming at least one current collector layer on each of the first and second substrate, forming an anode side of the battery by forming an anode on the current collector of the first substrate, forming a cathode side of the battery by forming a cathode on the current collector of the second substrate, depositing electrolyte on one or both of the anode and cathode, adhering and sealing the anode side and cathode side together such that the anode and cathode face one another with the electrolyte In between, and removing the flexible battery from the release liners. The battery may be a primary battery or a secondary battery. The method may be implemented using a roll-to-roll process.