Aging generally refers to the placement of the battery after the first charging and forming after the battery is assembled and injected. 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 charging.
The room temperature aging temperature is 25 degrees, and the high temperature aging is different from each factory, some are 38 degrees and 45 degrees. The time is between 48-72 hours.
Aging is divided into two situations: opening and sealing:
Regarding the battery formed by opening, if the relative humidity can be controlled below 2% for room temperature aging, it is better to seal after aging.
Regarding high temperature aging, aging after sealing is better.
However, it is certain that the aging process has electrochemical kinetic changes, which is of great help to the stability of SEI and can promote the stability of the electrochemical system.
The purpose of aging
In fact, the principle is similar. One reason is to allow the electrolyte to be fully infiltrated, and the other is that some active components in the positive and negative active materials are deactivated through a certain reaction, which makes the overall performance of the battery more stable. Many companies make this process Speed up and adopt high-temperature aging, but pay attention to controlling time and temperature for high-temperature aging, because high-temperature aging will cause more degradation to active substances than room-temperature aging. Uses are well controlled, active ingredients are fully reacted, and battery characteristics are stable and poorly controlled. , Overreaction, then the electrical performance will decrease, the capacity will decrease, the IR increase, or even leakage will occur.
The performance of the battery after high temperature aging is more stable. Most lithium-ion battery manufacturers adopt high temperature aging operation mode during the production process. The temperature is 45~50 degrees Celsius for 1~3 days, and then put it aside 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 directly test the comprehensive indicators of the safety and electrochemical performance of these batteries.
Nowadays, most battery companies use low-quality and low-end domestic separators for mass production. High temperature aging has also become a hidden rule for the safety performance of the internal structure of the battery.
