What are the basic reasons for the bulging of lithium batteries?

One. Overcharge caused by overcharge 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 the lithium battery pack. 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, causing the battery to 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 charging and discharging process, the important thing is that some organic matter will undergo reversible changes. After the battery is over-discharged, the SEI film will be reversibly broken, and the SEI protecting the negative electrode material will collapse after the destruction of the negative electrode material, thereby forming the bulging phenomenon of the lithium battery. If the charger used does not meet the requirements, it may cause the battery to swell at the slightest degree, and may cause a safety accident or even an explosion. 3. Processing and manufacturing process issues: The manufacturing level of lithium battery packs is uneven, the electrode coating is not uniform, and the processing technology is relatively rough. These three factors lead to a violent reaction similar to a short circuit in the lithium battery pack during use, generating a lot of heat, which in turn causes the electrolyte to decompose and vaporize, and the battery bulges. 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: What are the disadvantages of lithium battery electric vehicles?