Why do lithium battery packs undergo aging detection before they leave the factory?

Lithium battery pack aging generally refers to the placement of the battery after the battery is assembled and injected after the second charge. It can be aging at room temperature or high temperature. The purpose is to stabilize the properties and composition of the SEI film formed after the initial charge. The normal temperature aging temperature of lithium battery pack is 25 degrees, and the high temperature aging is different from each factory. Some are 38 degrees and 45 degrees, and the time is between 48-72 hours. There are several important purposes for the aging of lithium battery packs before they leave the factory. One is to make the electrolyte infiltration better, which is conducive to the stability of the performance of the lithium battery; the other is that the active materials in the positive and negative materials are aged, which can promote the acceleration of some secondary uses. Carry out, such as gas production, electrolyte analysis, etc., so that the electrochemical performance of the lithium battery pack can quickly stabilize; the third is to screen the consistency of the lithium battery pack after a period of aging. After formation, the voltage of the battery cell is unstable, and its measured value will deviate from the actual value. The voltage and internal resistance of the battery cell after aging are more stable, which is convenient for screening batteries with high consistency. The aging system has two important factors affecting the performance of lithium battery packs, namely, aging temperature and aging time. In addition, it is also important whether the battery is sealed or opened during aging. After high temperature aging, the performance of lithium batteries is more stable. Most lithium battery manufacturers use high temperature aging operation methods during processing, and they are aged at 45 to 50 degrees Celsius for 1 to 3 days, and then they are left at room temperature. Potential undesirable phenomena of the battery will be exposed after high temperature aging: for example, voltage changes, thickness changes, and internal resistance changes are a direct test of the comprehensive indicators of the safety and electrochemical performance of this batch of 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 post: Decompose the difference between lithium iron batteries and alkaline batteries