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

25 Oct 2021
Why do lithium battery packs undergo an aging test 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 aged at room temperature or at high temperature. The effect is to stabilize the properties and composition of the SEI film formed after the initial charge.

Lithium battery packs have a normal temperature aging temperature of 25 degrees, and high temperature aging varies from factory to factory, some are 38 degrees or 45 degrees, and the time is between 48-72 hours.

   There are several main purposes for the aging of lithium battery packs before leaving the factory. One is to make the electrolyte infiltration better, which is conducive to the stability of lithium battery performance;

   The second is that the active materials in the positive and negative materials can accelerate the progress of some side effects after aging, such as gas production, electrolyte decomposition, etc., so that the electrochemical performance of the lithium battery can quickly stabilize;

  The third is to screen the consistency of lithium battery packs after aging for a period of time. After the formation, the voltage of the cell is unstable, and the measured value will deviate from the actual value. The voltage and internal resistance of the cell after aging are more stable, which facilitates the selection of batteries with high consistency.

   There are two main factors that affect the performance of the lithium battery pack by the aging system, namely, the aging temperature and the aging time. In addition, it is also important whether the battery is sealed or opened during aging.

  The performance of lithium batteries after high temperature aging is more stable. Most lithium-ion battery manufacturers adopt high temperature aging operation mode in the production process, and the temperature is 45~50 degrees Celsius for 1 to 3 days, and then put 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 this batch of batteries.

  The impact of aging of lithium battery pack on battery performance

  1. stable performance

   At room temperature or high temperature, leave the lithium battery pack for a period of time for aging. This is beneficial for the electrolyte to fully infiltrate the pole pieces, which is convenient for stabilizing the performance of the lithium battery pack.

  2. SEI structure reorganization

After the lithium battery undergoes a pre-forming process, a certain amount of SEI film will be formed on the graphite negative electrode inside the battery, but this film has a compact structure and small pores. The battery will be aged at high temperature, which will help the SEI structure to reorganize and form a loose porous film. .

   3. Speed up side reactions

  Aging treatment will help the lithium battery pass the unstable stage of the battery voltage after formation as soon as possible. After the active material in the positive and negative electrode materials is aged, it can accelerate the progress of some side reactions, so that the electrochemical performance of the lithium battery pack can be stabilized more quickly.

It is normal for lithium battery packs to age, but they are often not used up to a limit. If they are not fully charged in time, they will age quickly. You can change the battery electrode or change the charging method to improve the unified charging and discharging process, thereby extending the battery life.


The aging test of the solar controller is to avoid any functional defects?

1. Overcharge protection: When the charging voltage is higher than the protection voltage, the battery will be automatically turned off to charge the battery. After that, when the voltage drops to the maintenance voltage, the battery will enter the floating charge state. When the voltage is lower than the recovery voltage, the float charge will be turned off and enter the equal charge state. .

2. Over-discharge protection: When the battery voltage is lower than the protection voltage, the controller automatically turns off the output to protect the battery from damage; when the battery is recharged, it can automatically restore power.

3. Load over-current and short-circuit protection: After the load current exceeds 10A or the load is short-circuited, the fuse is blown, and it can be used after replacement.

4. Overvoltage protection: When the voltage is too high, the output is automatically turned off to protect the electrical appliances from damage.

5. With anti-reverse charging function: Schottky diodes are used to prevent the storage battery from charging the solar battery.

6. With anti-lightning function: when there is a lightning strike, the varistor can prevent the lightning strike and protect the controller from damage.

7. Solar battery reverse connection protection: The solar battery "+" and "-" are connected reversely, and can continue to be used after correction.

8. Battery reverse connection protection: the battery "+" and "-" are connected in reverse polarity, the fuse is blown, and it can be used after replacement

9. Determine the lighting mode of the controller

The aging of solar lamps is critical to the yield of lamps

Yuefeng's controller is independently developed. After the controller is successfully developed, we will also assemble it with the lamp to verify it. The aging of solar lamps is a major inspection of the entire system. It will verify whether the battery is losing power or whether it is operating properly, the charging problem of the photovoltaic panel, and the problem of the controller setting. Quality control has been the unshakable cornerstone of Yuefeng for nearly 30 years, achieving 100% inspection. Serve more people and bring light to them.

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