NOVELTY - A hybrid lead acid battery and porous carbon supercapacitor energy storage device comprises a lead electrode comprising an active lead-based mass applied to a lead-based current collector (1) and a low conductivity sheet of porous material; carbon-based electrode comprising a sheet of highly conductive material sealed between two sheets of electrically conductive shield (2) material that is chemically resistant to the acid electrolyte, and highly porous carbon; and a casing that applies and maintains compression forces against the faces of the lead electrode and carbon-based electrodes.    USE - As a hybrid lead acid battery and porous carbon supercapacitor energy storage device.    ADVANTAGE - The device is easily assembled into multi-plate cells and manufacturable by conventional processes and with economical materials, provides a flexible and economical method of creating a multi-plate hybrid battery/supercapacitor energy storage device, provides chemically compatible highly conductive interface to the porous carbon electrode, and is highly inert with respect to the chemical interactions with the electrolyte.    DETAILED DESCRIPTION - A hybrid lead acid battery and porous carbon supercapacitor energy storage device comprises at least one lead electrode, at least one carbon-based electrode, a separator, a casing, and an acid electrolyte. The lead electrode comprises an active lead-based mass applied to a lead-based current collector, and a low conductivity sheet of porous material that envelops the lead based mass and the lead-based current collector to insulate the same and to permit passage of electrolyte and lead-based ions. The carbon-based electrode comprises a sheet of highly conductive material sealed between two sheets of electrically conductive shield material that is chemically resistant to the acid electrolyte, and highly porous carbon in electrical contact with the sheet of highly conductive material. The casing applies and maintains compression forces against the faces of the lead electrode and carbon-based electrodes, when assembled, and to provide a void space in the interior of an assembled energy storage device.    DESCRIPTION OF DRAWING(S) - The figure is an exploded view showing current collector subassembly elements.    Current collector (1)    Conductive shield (2)    Tab feature (3)    Seal area (4)