Self-Discharge Process in a Lead-Acid Battery

4 REACTION THERMODYNAMICS AND KINETICS 1.4.1 Self-Discharge Process in a Lead-Acid Battery [Pg.12]

The self-discharge process in a lead-acid battery is initiated by the mixed potentials of the negative and positive electrodes, and E , at open circuit. The open-circuit potential of the electrodes is determined by the two partial reactions on each negative and positive electrode. [Pg.12]

For a negative electrode, the equilibrium potential of the PbSOVPb is 0.35 V, which is more negative than the equilibrium potential of the H+/H2. This potential difference causes the following reactions to proceed on the negative electrode with no electron or ion transfer to the positive electrode [Pg.12]

On open circuit, when no current flows through the electrode, the active material reacts with sulfuric acid, which leads to the evolution of H2. When pressure builds up, the H2 escapes the cell through the release valve hence, the negative electrode undergoes an irreversible self-discharge reaction. [Pg.12]