Why do lithium iron phosphate batteries have swelling and leakage?

Reasons for the bulging of lithium iron phosphate battery pack one. Overcharge caused by overcharging will cause all the lithium atoms in the positive electrode material to run into the negative electrode material, causing the original full grid of the positive electrode to deform and collapse, which is also an important reason for the decline in the power of lithium-ion batteries. In this process, there are more and more lithium ions in the negative electrode, and the excessive accumulation makes the lithium atoms grow out of the tree stump crystals, which makes the lithium ion battery pack swell. two. The bulging SEI film caused by over-discharge will have a protective effect on the negative electrode material, so that the material structure is not easy to collapse, and the cycle life of the electrode material can be increased. The SEI film is not static, there will be a little change during the charge and discharge process, the important thing is that some organic matter will undergo reversible changes. The over-discharge of the lithium iron phosphate battery causes the SEI film to be reversibly broken, and the destruction of the SEI protecting the negative electrode material causes the negative electrode material to collapse, thereby forming a bulging phenomenon. The reason for the leakage of the lithium iron phosphate battery pack is that the sealant is aging and there are cracks in the seal; the lithium iron phosphate battery is seriously overcharged, and different types of lithium ion battery packs are mixed, and the battery gas recombination efficiency is poor; the acid splashes during the acid filling, Cause false leakage. Usually the output current is too large, the continuous discharge time is too long, and the temperature of the soft-packed lithium iron phosphate battery rises. There are also batteries that have been used for a long time with low current, and they may also leak. When welding the shell and cap of the lithium-ion battery pack, the welding is not firm, not sealed, there are problems such as missing welding, false welding, and cracks and cracks in the welding seam. How to deal with the bulging of the lithium iron phosphate battery pack 1. Please do not continue to use the bulging lithium iron phosphate battery. If the bulging situation occurs, replace the lithium ion battery pack with a new one as soon as possible. Try not to rely on some methods taught on the Internet to continue using the battery. 2. In normal times, don't charge while playing with your mobile phone. Regularly adhere to the battery condition to avoid dangerous situations. 3. Normally, when charging, pay attention to the choice of charger. For example, the rated charging voltage of the battery is 3.7V, and the limit voltage is 4.2V. Try not to choose a charger that exceeds this voltage. It is best to maintain a constant current. How to solve the leakage of lithium iron phosphate battery pack? 1. Discard these batteries. 2. Sell the leakage of lithium iron phosphate batteries to businesses that recycle batteries.