Prolonged Life and Fast Secondary Formation of the Electrodes of Lead-Acid Battery during Charge-Discharge Cycle under High-Pressure Crystallization

Abstract

To make larger capacity of charge–discharge of lead-acid batteries at high pressure after the initial formation of Plante-type electrodes, we studied the effect of high pressure on prolonged life testing. Electrode life was evaluated by determining the time of detachment of active crystals (Pb, PbOx and PbSO4) or the drop in ampere-hour efficiency during the charge–discharge cycle. Prolonged life testing, active crystals (Pb, PbOx and PbSO4) on the electrodes used in charge–discharge cycles at atmospheric pressure were easily detached when the electric current was increased to 2.7 mA/cm2, but the electrodes used at 100 MPa remained very tough until 8.0 mA/cm2 was reached. To increase the electric capacity of electrodes (i.e. in the second formation process), long-term charge–discharge was performed at a high electric current (5.3 mA/cm2). Faster second formation of electrodes at this high current was impossible at a charge of 3.6 As under atmospheric pressure, but it was possible at 6 As and 100 MPa.