Optimised energy storage device having capacitor material on lead based negative electrode

A lead-acid battery comprising:

• at least one negative electrode comprising lead-based battery electrode material and at least one region of capacitor material overlying the lead-based battery electrode material, each electrode being in electrical connection to an outer terminal of the battery, and
• at least one positive lead-dioxide based battery electrode without a capacitor material, each positive electrode being in electrical connection to a second outer terminal of the battery,
• separator interleaving the facing electrodes
• electrolyte filling at least the space of the electrodes and separators
• wherein the capacitor material overlying the lead-based battery electrode material comprises 34-65% by weight of a high electrical conductivity carbonaceous material, 35-52% of a high specific surface area carbonaceous material, at least 0.1% lead and binder, and a polymeric fiber reinforcement material in an amount up to 10% by weight, and
• wherein the capacitor material of each negative electrode constitutes between 1 and 15% by weight of the lead-based battery electrode material.

A lead-acid battery comprising:

• at least one negative electrode comprising lead-based battery electrode material and at least one region of capacitor material overlying the lead-based battery electrode material, each electrode being in electrical connection to an outer terminal of the battery, and
• at least one positive lead-dioxide based battery electrode without a capacitor material, each positive electrode being in electrical connection to a second outer terminal of the battery,
• separator interleaving the facing electrodes
• electrolyte filling at least the space of the electrodes and separators
• wherein the capacitor material overlying the lead-based battery electrode material comprises 34-65% by weight of a high electrical conductivity carbonaceous material, 35-52% of a high specific surface area carbonaceous material, at least 0.1% lead and binder, and a non-conductive polymeric fiber reinforcement material in an amount up to 10% by weight, and
• wherein the capacitor material of each negative electrode constitutes between 1 and 15% by weight of the lead-based battery electrode material.