Fabricating a capacitor includes performing an oxide formation operation on a sheet of material. The oxide formation operation forms an anode metal oxide on an anode metal. A thermal compression is performed on the sheet of material after the oxide formation operation is performed. The thermal compression applies thermal energy to the sheet of material while applying pressure to the sheet of material. After the thermal compression, the capacitor is assembled such that at least one electrode in the capacitor includes at least a portion of the sheet of material.