Phenomenon analysis of the natural loss of lithium-ion battery capacity

Li-ion battery self-discharge analysis Li-ion battery self-discharge refers to the natural loss of battery capacity when the battery is not in use. Under normal circumstances, the degree of self-discharge of the battery is mainly affected by factors such as cathode material, battery manufacturing process, electrolyte performance, temperature and time. Self-discharge will cause the battery to lose some capacity. The self-discharge of the battery is greatly affected by temperature and state of charge. If the negative electrode is in the state of charging and discharging and the positive electrode self-discharges, it will destroy the internal capacity balance of the battery and cause capacity loss*. During long-term or frequent self-discharge, lithium may be deposited on the carbon, exacerbating the capacity imbalance between the two electrodes. In practice, battery self-discharge also includes the power consumed by the battery management system. Lithium-ion batteries are battery packs discharged from automobiles. A single battery test module tests the voltage and temperature of each battery. The touch screen module detects the total voltage and current of the battery pack and controls the charging process of the battery pack. The number of batteries in each battery pack of low-voltage electric vehicles is 16, connected in series. totalvoltage is a touch screen module, used to detect the total voltage and total current of the battery pack, and display the total voltage, total current, cell voltage, temperature and other important information on the touch screen module in real time. The touch screen module communicates with the charger, balance module, and motor controller through the CAN bus at the same time to monitor the charging and discharging process of the power supply battery pack, which is the core of the management system. Through the analysis of the charge-discharge mechanism and self-discharge of lithium-ion batteries, the lithium iron phosphate cathode material has a regular olive-shaped structure. Lithium iron phosphate battery refers to a lithium ion battery using lithium iron phosphate as the positive electrode material. During charging and discharging, the polymer film separates the positive and negative electrodes, preventing electrons from passing through, and allowing lithium ions to pass through. The charge-discharge reaction mechanism can be known from the formula, and the charge-discharge reaction is carried out between the two phases of LFePODFeP04. During the charging process, lithium ions escape from UFeP0 and 4 and migrate to the negative electrode through the diaphragm, and the positive electrode forms FeP0 and 4 phases. During the discharge process, lithium ions escape from the negative electrode, migrate to the positive electrode through the separator, and insert FeP04 to form UFeP04. Since the coordination relationship of ferro-oxygen does not change much during charging and discharging, although there is a phase change in the process of removing lithium, there is no volume effect that affects the electrochemical performance of lithium. 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: What are the methods for charging lithium-ion battery electric vehicles?