A high power density energy storage device having enhanced operation voltage is provided. Such a device can include a cathode having a structured surface on a conductive substrate, an anode positioned adjacent to the cathode, where the anode includes a silicon substrate having a structured surface, and wherein the structured surface of the cathode is oriented toward the structured surface of the anode. The device can further include a dielectric material applied to the structured surface of the anode, a conductive material or a pseudocapacitive material applied to the structured surface of the cathode, and an electrolyte disposed between the cathode and the anode.