Analysis of the reasons for the self-discharge of valve-regulated lead-acid batteries

The self-discharge of the battery refers to the phenomenon that the battery discharges through the internal circuit during storage, which causes the capacity to decrease. Self-discharge is usually critical at the negative electrode, because the negative electrode active material is a more active spongy lead electrode, which can undergo displacement reactions. If there are metal impurities with low hydrogen evolution overpotential in the electrode, these impurities and the negative electrode active material can form a corrosive micro-battery. As a result, the negative electrode metal self-dissolves and hydrogen gas is precipitated, thereby reducing the capacity. Impurities in the electrolyte serve the same harmful purpose. Generally, the self-discharge of the positive electrode is not large. The positive electrode is a strong oxidant. If there are impurities that are easily oxidized in the electrolyte or on the separator, it will also cause the reduction of the positive electrode active material, thereby reducing the capacity. 2 Self-discharge of the positive electrode The self-discharge of the positive electrode is due to the analysis of the positive electrode active material during the storage period, the formation of lead sulfate and the precipitation of oxygen. 3 When the negative electrode self-discharge battery is in an open circuit state, the self-dissolution of lead leads to capacity loss. There are many factors that cause self-discharge, such as impurities in the electrolyte and plate materials, which cause local battery effect self-discharge; separators are broken and active materials fall off; there is infiltrating dust on the battery cover, and the electrolyte or water forms a self-discharge circuit. What we can do is to keep the battery cover dry and clean. The storage battery that is moved from outside the house to the house in winter will have condensed water, which can be wiped or left to evaporate before recharging. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: Failure mode of valve-regulated lead-acid batteries