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

1) The problem of manufacturing level Lithium battery bulging may be a problem of the manufacturing level of lithium iron phosphate battery pack. The electrode coating is uneven and the processing technology is relatively rough. (2) Overcharge of the lithium battery 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 factor in the decrease of the power of the lithium iron phosphate battery The reason. 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 battery pack swell. (3) The bulging phenomenon of the lithium iron phosphate battery pack will also 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) Bulging caused by over-discharge. During the first charge and discharge of a liquid lithium battery, the electrode material and the electrolyte react at the solid-liquid interface to form a passivation layer overlying the surface of the electrode material. The formed passivation film can effectively prevent the passage of electrolyte molecules, but Li+ can be freely inserted and extracted through the passivation layer, which has the characteristics of a solid electrolyte, so this passivation film is called SEI. The SEI film is not static, there will be a little change during the charging and discharging process, the most important thing is that some organic matter will undergo reversible changes. The over-discharge of the lithium iron phosphate battery pack causes the SEI film to be reversibly broken, and the SEI that protects the negative electrode material collapses after the destruction of the negative electrode material, thereby forming a bulging phenomenon. (5) The violent reaction of the short circuit generates a lot of heat, which in turn causes the electrolyte analysis to vaporize, and the battery bulges. (6) Reasons for the poor quality of lithium iron phosphate battery chargers. The charger uses inferior materials, innovative or low-quality components, heat generation, and inaccurate parameter drift, which makes the charging voltage limit out of control, causing the internal gas of the lithium battery to knead and cause the battery shell to deform and crack or even burst. (7) Long-term storage of lithium iron phosphate battery packs will also cause bulging. Since the air is conductive to a certain extent, if the battery is left for too long, it is equivalent to touching the positive and negative poles of the battery directly and slowly. 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: Lithium battery protection board wiring method and analysis of matters needing attention