I. Introduction
The phenomenon of lithium evolution is an important problem affecting the capacity of lithium batteries. This article will discuss the impact of lithium analysis on battery capacity with you in detail, and analyze its causes and solutions.

Second, the impact of lithium on battery capacity

1. Loss of active lithium ions
Lithium evolution causes some of the lithium ions to form lithium metal on the surface of the negative electrode, rather than being embedded in the negative electrode material. This means that the number of active lithium ions available for charging and discharging is reduced, resulting in a reduced battery capacity.
2. Growth of lithium dendrites
Lithium dendrites are needle-like crystals that grow on the surface of the negative electrode, which can penetrate the diaphragm and cause a short circuit inside the battery, further reducing the battery capacity. In addition, the growth of lithium dendrites will also increase the internal resistance of the battery and reduce the charge and discharge efficiency of the battery.
3. The battery performance deteriorates
Lithium evolution will lead to an increase in the internal resistance of the battery, reduce the efficiency of charge and discharge, and thus affect the performance of the battery. In addition, lithium evolution will also lead to an increase in the self-discharge of the battery and shorten the storage life of the battery.
4. Security risks

Serious lithium evolution may lead to internal short circuit of the battery, cause thermal runaway, and even burn or explosion, posing a threat to the life and property safety of the user.

Equivalent circuits for lithium-ion batteries

3. Factors that lead to lithium evolution
1. Charging speed is too fast
The high charging rate will cause the deposition rate of lithium ions on the negative surface to exceed its embedding rate, thus triggering lithium evolution.
2. Low temperature environment
At low temperatures, the diffusion rate of lithium ions slows down, and it is easy to precipitate on the negative surface to form lithium dendrites.
3. Overcharge and overdischarge
Overcharge will make the negative electrode potential too low, resulting in the reduction of lithium ions to lithium metal on the negative electrode surface; Overdischarge will make the positive electrode potential too high, resulting in lithium ions from the positive electrode can not be embedded in the negative electrode, and precipitation on the negative surface.

4. The battery is aging

With the use and aging of the battery, the structure and performance of the negative electrode material will change, making it more prone to lithium evolution.
Fourth, the solution to the problem of lithium analysis
1. Optimize battery design
By improving the structure and material of the battery, such as using a more stable negative electrode material, optimizing the aperture and thickness of the diaphragm, the occurrence of lithium evolution can be reduced.
2. Control charging conditions
The use of appropriate charging strategies, such as constant current and constant voltage charging, intelligent charging, etc., can control the charging rate and voltage, avoid overcharge and overdischarge, thereby reducing the risk of lithium evolution.
3. Improve the use environment
When the battery is used in a low temperature environment, appropriate insulation measures can be taken to increase the temperature of the battery to reduce the occurrence of lithium evolution.
4. Regular maintenance and testing
Regular maintenance and testing of the battery, timely detection and treatment of battery aging and other problems can extend the service life of the battery and reduce the risk of lithium analysis.

V. Conclusion
Lithium evolution of lithium batteries has a significant impact on battery capacity, resulting in the loss of active lithium ions, the growth of lithium dendrites, the deterioration of battery performance and the increase of safety risks. In order to reduce the occurrence of lithium evolution, it is necessary to take comprehensive measures to improve the performance and safety of the battery from the aspects of battery design, charging conditions, use environment and maintenance testing. Through in-depth research and continuous innovation, it is believed that the problem of lithium battery analysis can be better solved in the future, and the development and application of lithium battery technology can be promoted.