What are the important reasons for the bulging of lithium-ion batteries

1. Poor packaging: The proportion of bloated battery cells caused by poor packaging has been greatly reduced. Any poor packaging will lead to battery cells. Topsealing and Degassing are the most common. Topsealing is mainly due to poor sealing of the Tab position. Degassing is mainly due to delamination (including the separation of pp and Al due to the influence of electrolyte and gel). Poor packaging causes moisture in the air to enter the battery core, causing the electrolyte to decompose and produce gas. 2. Surface damage: The battery cell is abnormally damaged or artificially broken during the flow process, which causes the pocket to be damaged (such as pinholes) and moisture enters the battery cell. 3. Corner damage: due to the deformation of the aluminum at the corners of the folded edge, the air bag shaking will twist the corner and cause Al damage (the larger the battery cell, the larger the air bag, the easier it is to break) and lose its use as a barrier to water. Wrinkle glue or hot melt glue can be added to the corner to relieve it. In addition, it is forbidden to move the battery cells with air bags in each process after the top-sealing. Pay more attention to the operation method to prevent the battery cells from swinging on the aging board. 4. The internal water content of the battery core exceeds the standard: there are certain requirements for the water content in the battery core. Once the water content exceeds the standard, the electrolyte will fail and gas will appear after formation or degassing. The main reasons that cause the internal water content of the battery to exceed the standard are: the electrolyte water content exceeds the standard, the water content of the bare cell after Baking exceeds the standard, and the humidity exceeds the standard. If it is suspected that excessive water content causes flatulence, a retrospective inspection of the process can be carried out. 5. Long-term use and improper storage of any product If it is not used for a long time, the original performance will basically decline, the battery is not used for a long time, and then there is no better storage treatment. Do not use it when exposed to the air for a long time, and the battery is fully charged. Since air is conductive to a certain extent, too long a long time is equivalent to direct contact between the positive and negative electrodes of the battery, and a chronic short-circuit occurs. Once short-circuited, it will heat up, and some electrolytes will decompose or even vaporize, resulting in bulging. 6. The daily use habits of users are the users themselves. If users use lithium-ion battery products improperly, such as overcharging and over-discharging, or continuous use in extremely harsh environments, they may also cause swelling of lithium-ion batteries. . 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 should I do if the 18650 battery pack is broken?