What should be paid attention to when assembling lithium battery pack?

Matters needing attention in the cell composition of the battery pack: including cell screening, aluminum-plastic composite film, top sealing (edge u200bu200bsealing at the end of the pole), side sealing, protection of the pole, and measures to guard against mechanical shocks and short circuits. 1. The problem of battery screening, how to distinguish between good and bad after the battery is in hand. It is necessary to use internal resistance detectors and capacity detectors. Detect how much MH is nominal and how much MH is actually. If the gap from the nominal parameters is greater, the quality is worse. The lower the internal resistance of the battery, the better. The battery core is a pit. Check and detect if you have equipment. If you don’t have equipment, you can buy a lottery ticket. 2. Aluminum-plastic composite film outer packaging protection: It is important to be wary of being damaged by sharp parts. For this reason, the surrounding environment of the battery should be cleaned up from time to time, sharp parts are forbidden to touch or collide with the battery cell, and gloves can be worn when taking it, and beware of fingernail scratches on the battery cell surface. 3. Top sealing and side sealing protection: in order to guard against damage to the top sealing and side sealing and destroy the sealing effect, it is forbidden to bend the top sealing and the side sealing; at the same time, the cell design must adopt reliable insulation isolation The measure is to guard against the short circuit of the negative electrode and the aluminum-plastic composite film. 4. Pole handle protection: The positive lead terminal of the polymer lithium battery cell adopts an aluminum pole handle, and the negative lead terminal uses a nickel pole handle. Since the pole handle is thin, bending should be prohibited; at the same time, the pole handle should be kept in contact with the aluminum-plastic composite film during the processing, and the ferrule film should be used to strictly isolate it. 5. Insulation protection: When assembling multiple single cells in series, in order to prevent the battery polarity short circuit, insulation solution is required. Use PC film or silicone film to separate the battery lugs and then wrap multiple layers of insulation. Tape to fix it, and then add an insulating layer to the position of the welding wire, and then add striped glue to fix it. 6. Beware of mechanical shocks, such as falling, hitting, bending the battery cell and accidentally trampling on the battery. 7. It is forbidden to short-circuit the positive and negative poles with metal objects or wires. 8. Waterproof protection: The lithium battery is well packed, and then packed with insulating glue as a whole. Or choose a waterproof battery box. 9. The battery pack is required to be shockproof! Electric vehicles cannot be used as off-road vehicles in use! The outer skin of the battery pack cannot be used to buffer the collision, and deformation will cause a short circuit! Try to use the grille bracket + cushion + outer box. Without the grille bracket, the battery pack will cause the nickel sheet to fall off under the squeeze of many years of activities! 10. Do a good job of heat dissipation, use a thermal conductive silicone grease pad as a medium to guide the heat to the stainless steel shell. Or the battery pack has conditional supply of heat conduction channels, and during energy conversion, timely heat conduction can optimize the battery. Steel outer box + fan assist are all conventional methods. 11. Anti-corrosion problem. The battery will rust after being left for a long time. If possible, try to take anti-corrosion measures. After a cell is completed, the next step is to correctly combine the shell and cell protection circuit module to make it a polymer battery. The precautions in this process are as follows: 1. Shell design: (1) Sufficient mechanical strength Beware of mechanical damage to the cell by external forces. (2) When the cell is installed in the shell, be wary of the sharp edges and corners of the shell scratching the cell; (3) Beware of the short circuit caused by the contact between the pure aluminum of the aluminum-plastic composite film and the outside. 2. It is necessary to design the battery protection circuit: including the scientific setting of the highest/lowest voltage, over-current protection, the battery unit (single battery) must be protected from overcharge and over-discharge when the battery is used in combination. 3. The transfer of the positive aluminum pole handle through the nickel strip, and the connection between the battery cell and the circuit board should be performed by ultrasonic welding or spot welding technology. 4. Reliable positioning of the battery cell. After the battery cell is assembled, it should be fastened firmly in the shell, and will not loosen randomly, so that the entire lithium battery structure is in a consolidated state. 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: What kind of flexible packaging materials are required for polymer lithium batteries?