What are the general reasons for the bulging of lithium iron phosphate batteries?

1. Lithium-ion battery swelling caused by overcharging. Too much charging 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. This is also the decrease in the power of the lithium iron phosphate battery pack. An important reason. In this process, there are more and more lithium ions in the negative electrode. Too much extraction causes the lithium atoms to grow out of the tree stump crystals, which makes the lithium ion battery pack swell. 2. Bulging caused by over-discharge During the first charge and discharge process of the liquid lithium-ion battery, the electrode material and the electrolyte reverberate at the solid-liquid interface, forming a passivation layer surrounding the surface of the electrode material. The formed passivation film can effectively prevent the passage of electrolyte molecules, but Li+ can freely embed and escape the passivation layer, which has the characteristics of a solid electrolyte, so this passivation film is called SEI. The SEI film is not always stable, and there will be a little change in the charging and discharging process. The important thing is that the departmental organic matter will produce reversible changes. Too much discharge of the lithium iron phosphate battery pack causes the SEI film to be reversibly broken, and the SEI of the negative electrode material is crushed, which causes the negative electrode material to collapse, thereby forming a bulging phenomenon. 3. The problem of manufacturing degree The bulge of lithium ion battery is probably the problem of the degree of manufacturing of lithium iron phosphate battery pack. The electrode coating is uneven and the production process is relatively rough. Four. Lithium iron phosphate battery packs will also produce swelling if they are not eliminated for a long time, because the atmosphere is conductive at a certain level. Therefore, if the battery is left for too long, it is equivalent to direct war between the positive and negative electrodes of the battery, causing a chronic problem. Short circuit. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: How to use lithium-ion battery electric vehicles correctly?