The present invention relates to a high capacity electrochemical cell including an anode, a cathode, and a separator disposed between the anode and cathode. The anode is configured to operate in combination with a quantity of an oxide of copper in the cathode. The cell is capable of operating at a discharge voltage greater than 1.05 volts for at least an initial 5% of a cell discharge period at a current density of at least 5 mA/g, and can include a cathode active material that includes an oxide of copper.