Charging principle of lead-acid battery
The anode (PbO2) and cathode (Pb) in the lead battery are immersed in the electrolyte (dilute sulfuric acid), and 2V power will be generated between the two poles, which is based on the principle of the lead battery, through charging and discharging, the anode and cathode and electrolyte will undergo the following changes:
(anode) (electrolyte) (cathode)
PbO2 2H2SO4 Pb -- PbSO4 2H2O PbSO4 (Electric Discharge Reaction)
(lead peroxide) (sulfuric acid) (spongy lead)
The valence of Pb in PbO2 is reduced and the negative charge flows. The valence of Pb in spongiform lead increases and the positive charge flows.
(anode) (electrolyte) (cathode)
PbSO4 2H2O PbSO4 -- \"PbO2 2H2SO4 Pb (Charging reaction) (must be under energized conditions)
(lead sulfate) (water) (lead sulfate)
In the first lead sulfate, the valence of lead increases, it is oxidized, and positive charge flows into the positive electrode. The valency of lead in the second lead sulfate is reduced, and the negative charge flows into the negative electrode.
The battery obtains power from other DC sources, which is called charging. When charging, lead sulfate on the positive and negative plates will be decomposed and reduced to sulfuric acid, lead and lead oxide, while hydrogen is produced on the negative plate and oxygen is produced on the positive plate.
The concentration of acid in the electrolyte gradually increases, and the voltage at both ends of the battery rises. When the lead sulfate on the positive and negative plates are reduced to the original active substance, the charging ends.