In this work, copper oxide thin films have been evaluated for use as electrodes in thin film batteries. The films were deposited by dc sputtering at low power, in order to produce nanoparticulated films. Samples were deposited onto unheated or heated (420°C) substrates. Both kind of samples are nanoparticulated, with distinct grain sizes, and amorphous. The potential profiles and cycling capacity in lithium electrolyte were investigated and are similar to those obtained for copper oxide in powder form. The discharge capacity for samples deposited onto heated substrates depends on the previous treatment of the samples, and the stabilized capacity values are higher than for the samples deposited without intentional heating of the substrates, and suitable for use in lithium-ion microbatteries.