What are the influencing factors of battery self-discharge?

Influencing factors of self-discharge 1 cathode material The influence of the cathode material is important because the transition metal and impurities of the cathode material precipitate in the anode and cause an internal short circuit, thereby increasing the self-discharge of lithium batteries. Yah-MeiTeng et al. studied the physical and electrochemical properties of two LiFePO4 cathode materials. The study found that batteries with high iron impurities in the raw materials and during the charging and discharging process have high self-discharge rate and poor stability. The reason is that iron is gradually reduced and precipitated in the negative electrode, piercing the diaphragm, causing a short circuit in the battery, resulting in high self-discharge . 2 Anode material The influence of the anode material on self-discharge is mainly due to the irreversible reaction between the anode material and the electrolyte. As early as 2003, Aurbach et al. proposed that the electrolyte is reduced to release gas, which exposes part of the graphite surface to the electrolyte. In the process of charging and discharging, when lithium ions are inserted and extracted, the graphite layered structure is easily destroyed, which leads to a higher self-discharge rate. 3 Electrolyte The important performance of the electrolyte is: the corrosion of the negative electrode surface by the electrolyte or impurities; the dissolution of the electrode material in the electrolyte; the electrode is covered by the insoluble solid or gas decomposed by the electrolyte to form a passivation layer. At present, a large number of scientific researchers are committed to developing new additives to suppress the influence of electrolyte on self-discharge. Jun Liu et al. added VEC and other additives to the MCN111 battery electrolyte and found that the high temperature cycle performance of the battery improves, and the self-discharge rate generally decreases. The reason is that these additives can improve the SEI film, thereby protecting the negative electrode of the battery. 4 Storage state The general influencing factors of storage state are storage temperature and battery SOC. Generally speaking, the higher the temperature, the higher the SOC and the greater the self-discharge of the battery. Takashi et al. conducted capacity decay experiments on lithium iron phosphate batteries under static conditions. The results show that with the increase of temperature, the capacity retention rate gradually decreases with the shelf time, and the battery self-discharge rate increases. 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 article: What are the advantages of vanadium storage batteries?