Aspects of the present invention provide a high capacity electrochemical cell having an anode, a cathode, and a separator disposed between the anode and cathode. The cathode includes a mixture having a first component, a second component and a third component. The first component includes a first element, the second component includes a second element, and the third component includes the first element and the second element. The mixture can, for instance, be a mixed metal oxide. The separator is configured to provide suitable ionic transport between the anode and the cathode.