Thermal runaway problem of lead-acid batteries

- Aug 16, 2019-

(1) The oxygen "channel" becomes clear, and the oxidation generated by the positive electrode easily reaches the negative electrode through the "channel";

(2) The heat capacity is reduced. The largest heat capacity in the battery is water. After the water is lost, the heat capacity of the battery is greatly reduced, and the generated heat causes the battery temperature to rise rapidly;

(3) Due to the shrinkage of the ultra-fine glass fiber separator in the battery after water loss, the adhesion to the positive and negative plates is deteriorated, the internal resistance is increased, and the heat generation during charging and discharging is increased. After the above process, the heat generated inside the battery can only be dissipated through the battery slot. If the heat dissipation is less than the heat generation, the temperature rise occurs. When the temperature rises, the battery's gassing overpotential decreases, the gassing amount increases, and a large amount of oxidation of the positive electrode passes through the "channel", reacting on the surface of the negative electrode, emitting a large amount of heat, causing the temperature to rise rapidly, forming a vicious circle, so-called "thermal runaway ".


(1) The oxygen "channel" becomes clear, and the oxidation generated by the positive electrode easily reaches the negative electrode through the "channel";

(2) The heat capacity is reduced. The largest heat capacity in the battery is water. After the water is lost, the heat capacity of the battery is greatly reduced, and the generated heat causes the battery temperature to rise rapidly;

(3) Due to the shrinkage of the ultra-fine glass fiber separator in the battery after water loss, the adhesion to the positive and negative plates is deteriorated, the internal resistance is increased, and the heat generation during charging and discharging is increased. After the above process, the heat generated inside the battery can only be dissipated through the battery slot. If the heat dissipation is less than the heat generation, the temperature rise occurs. When the temperature rises, the battery's gassing overpotential decreases, the gassing amount increases, and a large amount of oxidation of the positive electrode passes through the "channel", reacting on the surface of the negative electrode, emitting a large amount of heat, causing the temperature to rise rapidly, forming a vicious circle, so-called "thermal runaway ".