The present invention relates to a double electric layer heterogeneous electrochemical supercapacitor (HES) and a method of manufacture. Single-cell or multi-cell versions of the HES can be produced. Output characteristics of the HES are optimized by carefully controlling particular parameters of the HES' design and construction. For example, the ratio between the charging capacities of the positive electrode and negative electrode of the HES is carefully selected and controlled, an active material of higher efficiency than the active material used by typical electrochemical capacitors is preferably utilized in the construction of both the positive and negative electrodes, a separator with improved operating parameters is used, and the negative electrode current collector is preferably manufactured from a material having a matching layer--which ensures high conductivity, high hydrogen gassing overpotential, and high stability within a range of negative electrode operating potentials within the electrolyte environment of the HES.