Abstract: A nickel alloy material for use as a cathode of an electrochemical charge storage device (10) provides significantly higher charge densities than available in prior art devices. The nickel alloy electrode (30) includes a host matrix material such as nickel, molybdenum, chromium, and combinations thereof, and at least one modifier element selected from the group consisting of cobalt, iron, aluminum, titanium, tungsten, vanadium, zirconium, niobium, and combinations thereof. The rechargeable electrode material may be incorporated into a charge storage device such as an electrochemical capacitor, and including an electrode fabricated of the material (30), an anode (20), and an electrolyte (40) disposed therebetween.