Performance based design alternatives for conductive fiber products in monopolar and bipolar lead-acid batteries

Abstract

Advances in rechargeable battery systems have been made which provide next generation lead-acid batteries superior to nickel cadium and conventional state-of-the-art lead-acid batteries. Major advances have resulted in the fields of electrically conductive additives for monopolar batteries and high power, high capacity bipolar lead-acid batteries. The advances in conductive additives have taken the practical form of a conductive fiber additive that improves electrical conductivity and electronic network maintenance within the positive active material. The additives can be readily incorporated into the positive active material (PAM) used in monopolar lead-acid batteries to significantly improve battery performance. The conductive additive allows higher active material utilization efficiency i.e. increased battery capacity at various states of discharge, faster recharge and higher finishing currents that minimize excess gassing and grid corrosion, longer life from more efficient battery charge and discharge cycles, i.e. less positive plate shedding and softening and lower battery manufacturing costs from faster formation and lower input energy requirements. The high capacity, high power bipolar lead-acid battery represents a major technology advance. It is characterized by six important features: (1) High capacity and energy, (2) 50+% reduction in weight and volume, (3) High power, (4) Lightweight bipolar polymer composite structure and ruggedness - no heavy lead grids -no heavy intercell connects, (5) Large cross section areas and low internal resistance, and (6) Maintenance free no watering system - no high temperature thermal insulation - no hydrogen gassing. The Bipolar Energy Storage battery has excellent voltage design flexibilty for the production of from 6 to 48 volt batteries. Typically a 12 volt battery has a thickness of from 3/4 inch to a 1 1/2 inch and length/width which can vary from 3 inches to 14 inches on each side. Performance values developed to date for nonoptimized 4, 6 and 12 volt batteries (ENSCI -(EV) 1) show performance superiority of the Bipolar batteries in specific power and energy as compared to monopolar batteries. It is projected based on current design data that optimized ENSCI - EV 2 batteries in current prototype manufacture will have a specific energy from 55 to 60 Wh/Kg.