Lithium battery working principle and charging and discharging requirements analysis

What are the positive electrode materials for the working principle of lithium batteries: LiMn2O4, negative electrode material: Li+ in the positive electrode and Li+ in the electrolyte are concentrated on the negative electrode when the graphite is charged, and electrons are obtained, which are reduced to Li and embedded in the carbon material of the negative electrode. During discharge, Li embedded in the carbon material of the negative electrode loses electrons and enters the electrolyte, and the Li+ in the electrolyte moves to the positive electrode. The positive and negative materials of lithium batteries are both mixed conductor intercalation compounds of ions and electrons, and electrons can only move in the positive and negative materials. The charging and discharging process requires the common use of lithium ions and electrons, which requires the lithium ion electrode material to have good conductivity and ion diffusion ability to ensure that electrons are quickly conducted to the external circuit through the electrode tabs during the discharge process. Lithium ions rapidly diffuse into the electrolyte after being deintercalated from the negative electrode material; the lithium ions in the electrolyte are delivered to the positive electrode material by the carrier, and combine with electrons to form an intercalation compound. Lithium battery.jpg Lithium battery charging and discharging requirements 1. Lithium battery charging The maximum end-of-charge voltage of a single-cell lithium battery is 4.2V, which cannot be overcharged, otherwise the battery will be scrapped due to the loss of too much lithium ions in the positive electrode. When charging the lithium battery, a dedicated constant current and constant voltage charger should be used. First, charge with constant current until the voltage at both ends of the lithium battery is 4.2V, then switch to constant voltage charging mode; when the constant voltage charging current drops to 100mA, Charging should be stopped. 2. Discharge of lithium batteries Due to the internal structure of lithium batteries, all lithium ions cannot move to the positive electrode during discharge, and some lithium ions must be retained in the negative electrode to ensure that lithium ions can be inserted into the channel smoothly during the next charge. Otherwise, the battery life will be shortened. In order to ensure that some lithium ions remain in the graphite layer after discharge, it is necessary to strictly limit the minimum discharge termination voltage, which means that the lithium battery cannot be over-discharged. The discharge termination voltage of a single-cell lithium battery is usually 3.0V, and the minimum cannot be lower than 2.5V. The length of battery discharge time is related to battery capacity and discharge current. 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: Characteristics and current situation of my country's lithium battery manufacturing industry