Causes of bulging polymer lithium battery packs

　　 1. The problem of the manufacturing level of lithium battery packs, the electrode coating is not uniform, and the production process is relatively rough;

　　2. The violent short-circuit reaction generates a lot of heat, which causes the electrolyte to decompose and vaporize, and the lithium battery bulges;

3. In addition, the bulging phenomenon of polymer lithium battery pack will occur if it is not used for a long time, because the air is conductive to a certain extent, therefore, if the battery is left for too long, it is equivalent to the direct contact of the positive and negative electrodes of the battery, and the chronic Short circuit.

　　 4. Reasons for the poor quality of lithium battery chargers. The charger uses inferior materials, refurbished or inferior components, heat generation, and parameter drift is more accurate, causing the charging voltage limit to be out of control, resulting in the compression of the internal gas of the lithium battery, which causes the battery shell to deform and crack or even explode.

　　 5. The charging time is too long. If overcharging will cause a large amount of gas to wash the plates, cause the active material inside the lithium battery pack to fall off, shorten the battery life, make the battery lose water faster, affect the decomposition of the electrolyte, increase the temperature of the battery, and make it full!

　　 One, preparations

　　 Find a ventilated place, prepare the polymer lithium battery pack, scissors, bill holder, toothpicks, 705 transparent silicone rubber, scotch tape, syringe, and infusion needle with a section of plastic tube (must be relatively small);

　　 2. Pumping preparation

　　Connect the syringe to the infusion needle, hold the needle in a suitable position at the seal of the lithium battery pack, and then fix the needle with tape to keep it from shifting. Use a toothpick to take a small amount of 705 silicone rubber and apply it near the needle to prevent air leakage.

　　 Three, gas extraction

Pull the syringe to extract the gas from the battery. After a tube is filled, clamp the plastic tube of the needle with a bill holder to separate the syringe from the needle and discharge the gas. (Although the gas in the battery is non-toxic, it smells bad, so look for one A ventilated place), then connect the syringe to the needle and repeat the operation.

　　Four. Seal

　　After many operations, the aluminum encapsulation film of the battery will gradually tighten and close to the battery body, and the polymer lithium battery pack will also become very hard. When the gas cannot be pumped out and the inside of the battery is close to the vacuum state, clamp the plastic tube behind the needle with a clip, cut a small piece (1cm square) of transparent tape with scissors, stick it to the needle hole, press it and set the needle, the operation is complete.

　　 Five, quality inspection

　　Because the pinhole is very small, and it is sealed with silicone rubber and transparent tape, the gas will not enter the battery again. After a few hours after the silicone rubber is cured, test the lithium battery pack. First, use a small current to fully charge and discharge it several times. If the problem of outgassing no longer occurs, the treatment is completed. If there is still gas generated, you can follow the above process again and operate again. If it still cannot be solved, it means that the battery has been scrapped. After the above-mentioned treatment, the more than ten swollen polymer lithium batteries that I bought at a low price on the shopping network have been restored to normal use with good results.