Design Fundamentals of High Power Density, Pulsed Discharge, Lead Acid Batteries: I . Experimental

The design of a battery with maximum specific power to be discharged for 0.01s or less was explored. Key elements of the design are bipolar construction, using thin components with high electronic conductivity in the bipolar separator and high ionic conductivity in the electrolyte, and the use of an electrochemical couple with high open‐circuit potential and fast electrode kinetics. Bipolar lead‐acid stacks were assembled which showed specific powers of 100–800 kW/kg with current densities of up to 10–40 A/cm2 for up to 100 μs. Single lead‐acid cell tests showed that acid concentration, separator thickness and conductivity, discharge potential, and formation time all had a major impact on the cell power output. Tests showed that these cells are capable of well over a million shallow discharge/charge cycles. Evidence indicates that formation severely reduces cell current densities after 200–400 μs of discharge. In the first 200 μs, concentration depletion at the reaction interface appears to be a factor in current decline.