Analyze the internal structure and charging and discharging requirements of lithium batteries

Internal structure of lithium batteries: Lithium batteries usually have two shapes: cylindrical and rectangular. The inside of the battery adopts a spiral wound structure, and uses a very fine and permeable polyethylene film to block the data between the positive and negative distances. The positive electrode includes a lithium ion collector composed of lithium and cobalt and a current collector composed of aluminum film. The negative electrode is composed of a lithium ion collector made of carbon sheet data and a current collector made of copper film. The battery is charged with an organic electrolyte solution. Equipped with other safety valves and PTC components to protect the battery from damage when the battery is abnormal and the output is short-circuited. The voltage of a single lithium battery is 3.6V, and the capacity is not unlimited. Therefore, a single lithium battery is often processed in series and parallel to meet the requirements of different occasions. Lithium battery charging and discharging requirements; 1. Lithium battery charging: According to the structural characteristics of the lithium battery, the maximum terminal voltage for charging is 4.2v, which cannot be overcharged. Otherwise, the battery will become obsolete because too much lithium ions are carried away from the positive electrode. It has high charging and discharging requirements and can be charged with a dedicated constant current and constant voltage charger. Constant current charging is generally converted to constant voltage charging after 4.2v/node. When the constant voltage charging current drops to less than 100mA, the charging should be stopped. Charging current (mA) u003d 0.1~1.5 times the battery capacity (such as 1350mAh battery, the charging current can be controlled between 135~2025mA). The normal charging current can be selected at 0.5 times the battery capacity, and the charging time is about 2 to 3 hours. 2. Lithium battery discharge: Due to the internal structure of the lithium battery, the discharge of lithium ions may not be all moved to the positive electrode. Lithium ions must be kept in a part of the negative electrode to ensure that the next rechargeable lithium ion can be embedded in the channel smoothly. Otherwise, the battery life will be shortened accordingly. In order to ensure that some lithium ions remain in the graphite layer after discharge, the minimum voltage at which the discharge is terminated should be strictly limited, that is, the lithium battery cannot be over-discharged. The discharge termination voltage is generally 3.0v/node, and the minimum is not less than 2.5v/node. The length of battery discharge time is related to battery capacity and discharge current. Battery discharge time (hours) u003d battery capacity/discharge current. The discharge current (mA) of lithium batteries should not exceed 3 times the battery capacity. (Such as 1000mAH battery, the discharge current is strictly controlled within 3A) Otherwise, the battery will be damaged. Lithium battery packs currently on the market are all sealed with a matching charge and discharge maintenance board. Just control the external charge and discharge current. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous article: Why does high temperature cause lithium battery explosion?