Some Aspects of Gas Recombination in Lead-Acid Systems

Abstract

It is shown that in a structurally controlled lead-acid cell the electrodes, in addition to their electrochemical function, also provide evolved gas re-combination sites. The reaction kinetics and the transport properties in the acid electrolyte solution are making the process possible at practical rates. Typical recombination rates for oxygen are of the order of 15 mA/cm 2 (C/10). For hydrogen, the observed starting rate of recombination exceeds self-discharge evolution in a lead-calcium system by a factor of at least 30. A review of various operational characteristics is given including half-cell potentials, cell voltages, internal pressures, and hydrogen partial pressures.