Introduce the internal structure of lithium-ion batteries

The internal structure of the lithium-ion battery is spirally wound inside the battery, and there is a very fine permeable polyethylene film separator between the positive electrode and the negative electrode. The positive electrode includes a lithium ion collector composed of lithium and cobalt and a current collector composed of aluminum film. The cathode is composed of a carbon sheet lithium ion collector and a copper film current collector. The battery is charged with an organic electrolyte solution. Safety valves and PTC components are also supplied to protect the battery from damage and output short-circuit under abnormal conditions. Lithium-ion batteries usually have two shapes: cylindrical and rectangular. The charging and discharging of lithium-ion batteries requires the discharge of lithium-ion batteries: due to the internal structure of lithium-ion batteries, lithium ions cannot move to the positive electrode during discharge, and some lithium ions must be maintained in the negative electrode to ensure smooth insertion of lithium ion channels in the future. Otherwise, the battery life will be shortened accordingly. In order to ensure that some lithium ions remain in the graphite layer after discharge, it is necessary to strictly limit the minimum voltage at which the discharge is terminated, that is, the lithium ion battery cannot be over-discharged. The discharge termination voltage is generally 3.0V/node, and the minimum should not be less than 2.5V/node. The battery discharge time is related to the battery capacity and discharge current. Battery discharge time (hours) u003d battery capacity/discharge current. Li-ion battery discharge current (mA) 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. Charging current (mA)u003d0.1~1.5 times battery capacity (such as 1350mAh battery, its charging current can be controlled between 135~2025mA). The traditional charging current is about 0.5 times the battery capacity, and the charging time is about 2 to 3 hours. Lithium-ion battery charging: According to the structure and characteristics of the lithium-ion battery, the highest end-of-charge voltage is 4.2v, and it cannot be overcharged, otherwise the battery will be scrapped due to excessive lithium ions in the positive electrode. It has high charging and discharging requirements and can be charged with a dedicated constant current and constant voltage charger. Under normal circumstances, constant current charging is converted to constant voltage charging after 4.2v/knot. When the constant voltage charging current is lower than 100mA, the charging should be stopped. 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: Explain the principle of over-discharge protection of lithium-ion batteries