Reduction of the dependence of modern society on fossil fuels is urgent. Electric power from wind and solar energy can be stored in a rechargeable battery. What is needed to reduce greenhouse gases is a safe, low-cost rechargeable battery with a high volumetric energy density and long cycle life for powering an all-electric road vehicle that is competitive in performance and in convenience with today's automobiles. The ability to plate dendrite-free alkali-metal anodes from a solid glass alkali-ion electrolyte with negligible anode/electrolyte interface impedance for transport of the working cation and a long cycle life at high rates has invited exploration of reversible plating of the alkali metal of the anode onto the cathode current collector. The voltage is limited by the energy difference between the Fermi levels of the anode and the cathode current collector, but the voltage can be tuned by a catalytic relay. Investigation of the concept with a copper current collector and an S8 or MnO2 catalytic relay has demonstrated proof of concept; with γ-MnO2 and a lithium anode, a discharge voltage of 3.08 V at commercial rates has been cycled over 250 times at room temperature with no lowering of the energy density.