Electrode and current collector for electrochemical capacitor having double electric layer and double electric layer electrochemical capacitor formed therewith

An electrode and a DEL capacitor formed therewith. The electrode will typically be a polarizable electrode, and may be formed of an activated carbon material having a substantially zero ash percentage and a low percentage of transition metals. In constructing a DEL capacitor employing such an electrode, a non-polarizable electrode formed from a lead dioxide/lead sulfate compound is preferably also used. The DEL capacitor may utilize an acid-based electrolyte, such as an aqueous sulfuric acid electrolyte. Consequently, the present invention also includes a current collector that preferably comprises a base material formed from a lead or a lead compound and a protective coating material that is resistant to an acid-based electrolyte. Preferably, the protective coating material is formed from a polymer base and a conductive dope that may thereafter be applied to the current collector base material by a variety of methods.