Learning The Self discharge Of Lithium-ion Battery
The self-discharge of lithium-ion batteries is a concern that needs attention. It is mainly caused by internal chemical reactions and physical processes, such as extreme electric-consuming reactions and impurities in materials. Testing methods like resting test and cycling test can be used to evaluate the level of self-discharge.
Jul 12th,2023543 Views
Lithium-ion batteries, being one of the most widely used batteries, are preferred for many electronic devices and energy storage systems due to their high energy density and long lifespan. However, a concern that needs attention and resolution is the self-discharge of lithium-ion batteries when they are not in use.
Self-discharge refers to the phenomenon where the charge of a lithium-ion battery gradually diminishes without any charging or discharging operation taking place. This is primarily caused by internal chemical reactions and physical processes within the battery. So let’s figure out the main reasons behind the self-discharge of lithium-ion batteries.
Reasons On the one hand, electrochemical reactions affect self-discharge of lithium-ion battery deeply. Within the battery, the electrolyte undergoes reactions with the electrode materials, leading to the loss of charge in the electrode materials. Extremely electric consuming reaction happens during this process.
On the other hand, impurities in materials is the factor causing self-discharge of lithium-ion battery possibly. During the manufacturing process of battery materials, impurities may be present, which can induce self-discharge in the battery. In particular, there may exist a small conductivity between the positive and negative electrodes, causing a gradual loss of charge.
Methods To determine the level of self-discharge in lithium-ion batteries, some testing methods can be employed. Usually, we determine how much self-discharge of battery is within unit time by K value. So what is K value? In the battery field, K value is the judgement that how much the battery discharges spontaneously within unit time. Ufine New Energy as a professional Lithium-ion Cell Manufacturer, devote itself to developing rechargeable Lithium-polymer battery pack. It has testing methods to test the level of self-discharge.
1. Resting test: The battery is placed at room temperature without any charging or discharging operation, and the loss of charge is periodically measured. By comparing the charge loss at different time intervals, the level of self-discharge can be assessed.
2. Cycling test: The battery undergoes a series of charging and discharging cycles, followed by a resting period at room temperature, and the loss of charge is measured again. By comparing the charge loss before and after cycling, the self-discharge of the battery can be evaluated.
It is worth mentioning that, UFX605080 3000mah, a battery 3.7v, is one of our typical product which calls professional customized hand warmer rechargeable LiPo Battery. It has passed above tests and shows a excellent performance on alleviating self-discharge of battery.
Improvement
As known as the self-discharge of lithium-ion battery unavoidable, to mitigate the self-discharge issue in lithium-ion batteries, various improvement measures can be implemented:
1. Optimize battery design: By improving the battery structure and using high-purity battery materials, the self-discharge of the battery can be reduced. Low-purity battery material is easy to make SEI thicker, which will increase the loss of active lithium. High-purity battery material is conductive to preventing the loss of active lithium.
2. Control the manufacturing process: During battery manufacturing, strict control over material purity and manufacturing processes can minimize factors that may cause self-discharge. It is necessary to strictly control the dust into the production workshop, reduce the impurities in the raw materials as much as possible, and do a good job of cleaning the production area.
3. Lower storage temperature: Storing the battery at lower temperatures can slow down the rate of self-discharge. Low temperature is fit for storing battery because the activity of lithium ion in low temperature environment is relatively negative. The lithium ion moves slower in low temperature comparing the normal temperature.
4. Reduce moisture: By optimizing the baking process of the pole core, developing roll baking process and controlling water absorption during battery injection, the moisture should be reduced as much as possible.
Conclusion In conclusion, self-discharge is a concern that needs attention and resolution in lithium-ion batteries. By understanding the reasons behind self-discharge, employing testing methods for evaluation, and implementing appropriate improvement measures, the self-discharge of lithium-ion batteries can be minimized, thereby enhancing battery performance and lifespan.
