| When assembling lithium battery, we must pay attention to these problems |
| Date：2020-12-22 Hits：519 |
| 1、 The matters needing attention in the use of the cell include the selection of the cell, the aluminum-plastic composite film, the top edge sealing (pole end sealing), the side sealing, the pole handle protection and the measures to avoid mechanical impact and short circuit. 1. The problem of battery screening is how to distinguish the good from the bad after the cell is in hand. Internal resistance tester and capacity tester must be used. Test the nominal MH and the actual MH. The larger the difference from the nominal parameter, the worse the quality. The lower the internal resistance of the battery, the better. The battery cell is a pit. If you have equipment, you can check and test it. If you don't, you will buy lottery tickets 2. Aluminum plastic composite film packaging protection: mainly to avoid being stabbed by sharp parts and damage. Therefore, it is necessary to clean the surrounding environment of the battery from time to time. Sharp parts are not allowed to contact or collide with the battery cell. Gloves can be worn when taking the battery to avoid scratching the surface of the battery cell by fingernails. 3. Top sealing and side sealing protection: in order to avoid damage of top sealing edge and side sealing edge and damage sealing effect, bending top sealing edge and side sealing edge shall be prohibited; meanwhile, reliable insulation and isolation measures must be taken in the design of cell to avoid short circuit between negative electrode and aluminum plastic composite film. 4. Pole handle protection: aluminum electrode handle is used for positive lead-out terminal of polymer lithium battery cell, and nickel electrode handle is used for negative electrode lead-out terminal. Because the pole handle is thin, bending should be prohibited; at the same time, the pole handle should be avoided from contacting with the aluminum plastic composite film in the production process, and the ferrule film should be strictly isolated. 5. Insulation protection: when assembling multiple single cells in series, in order to prevent the battery polarity short circuit, insulation treatment should be carried out. At the battery pole ear position, PC film or silica gel sheet should be used to separate and then multi-layer insulating tape should be wrapped to fix it. After that, a layer of insulation layer should be added at the position of welding wire, and then the stripe glue should be added to fix it. 6. Avoid mechanical impact, such as falling, striking, bending the cell and trampling on the battery. 7. It is forbidden to short circuit the positive and negative poles with metal objects and wires. 8. Waterproof protection: lithium battery is assembled, and then packaged after pouring insulating glue. Or choose waterproof battery box 9. Shock proof battery pack required! Electric vehicle in use, can not be used as an off-road vehicle! Also can't use the battery pack skin to achieve buffer collision, deformation will cause short circuit! Try to use grille bracket + cushion + outer box. Without grid support, the battery pack will fall off after years of active extrusion! 10. Heat conduction is conducted on the shell with silicone grease. Or, the battery pack can provide the optimal thermal conduction channel in time. Steel box + fan auxiliary, are conventional solutions. 11. Anti corrosion problem: the battery rusts after being put away for a long time. 2、 After a cell is finished, the next step is to correctly combine it with the shell and the 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 to avoid mechanical damage of cell under external force, (2) When the cell is installed in the shell, the sharp edges and corners of the shell shall not scratch the cell; (3) To prevent the aluminum plastic composite film sandwich pure aluminum and external contact and short circuit. 2. Cell protection circuit must be designed, including scientific setting of maximum / minimum voltage, over-current protection, overcharge and over discharge protection for battery cell (single cell) when combined. 3. The connection of positive aluminum pole handle through nickel bar and the connection between cell and circuit board shall be carried out by ultrasonic welding or spot welding technology. 4. After the cell is assembled, the cell shall be firmly fixed in the shell, and will not be loosened at will, so that the whole lithium battery structure is in a consolidated state. |
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