The main reason for the bulging of the mobile power polymer battery is the gas generated inside the lithium-ion battery. Almost all lithium-ion batteries have the first performance when they are damaged. The gas is generated inside the battery. The core, which is manifested as the swelling of the battery, so the swelling of the battery is also an early warning of damage to the battery or possible safety problems. 

    1. The battery cell is overcharged. As mentioned above, when the battery cell voltage exceeds 4.2V, a series of chemical reactions will generate gas inside. If the battery is slightly overcharged for many times, the gas inside the battery cell Gradually gather and swell the battery core.

    2. The cell is over-discharged. When the cell is over-discharged and stored for a long time, due to the electrolytic reaction inside the cell, the copper in the anode current collector decomposes to generate gas, which will generate gas inside the cell.

    3. The gas generated by the polymer lithium battery cell in the normal working voltage range. When the battery cell is just made, we will perform several cycles of charging and discharging to produce a layer of compound on the surface of the electrode to protect the pole piece , And will no longer participate in the reaction in the future charge and discharge process.

    4. When the sealing of the polymer lithium battery core packaging material is damaged, water molecules in the air enter the battery core, which will also cause serious swelling inside the battery core.

    5. The quality of the lithium battery itself is not good enough. The manufacturer of the lithium battery is cost-saving, or the process technology is not mature, and all aspects of the production of the lithium battery cannot meet the standards. This will cause the problem of the swelling of the lithium battery and even a serious safety hazard.