Lithium-ion batteries are widely used in portable electronic devices, electric vehicles, and energy storage systems. They are popular due to their high energy density, low self-discharge, and long cycle life. However, high temperatures can negatively affect the performance and lifespan of these batteries.
The optimal operating temperature for lithium-ion batteries is between 15°C and 25°C. When exposed to temperatures above 40°C, the battery's capacity and cycle life gradually decrease. If the temperature goes beyond 60°C, irreversible damage to the battery occurs, leading to a permanent loss of capacity and a shorter lifespan.
When high temperatures affect lithium batteries, they can lead to several problems.
1. Capacity loss: The capacity of a battery gradually decreases in a high-temperature environment. This phenomenon occurs because high temperatures intensify chemical reactions inside the battery and ultimately lead to a less efficient electrochemical reaction. Consequently, the amount of energy that the battery can store is reduced.
2. Shorter battery life: High temperatures can accelerate the process of battery aging. This is because at elevated temperatures, the chemical reactions within the battery occur at a faster pace, causing material degradation and electrolyte decomposition. As a result, the overall life of the battery is significantly reduced.
3. Increased safety risk: Elevated temperatures can intensify the pressure and heat produced within the battery, leading to a higher risk of thermal runaway, leakage, expansion, or even explosion. Thermal runaway can be triggered by internal and external factors, including overcharging, mechanical damage, and exposure to high temperatures. Consequently, this presents a potential hazard to the user and the environment in close proximity.
4. Decreased charging efficiency: High temperatures can enhance electrolyte activity, thereby facilitating faster ion migration. Nonetheless, if the temperature exceeds a certain threshold, the electrolyte's viscosity increases, which in turn slows down ion migration. High temperatures accelerate the evaporation of the electrolyte and structural changes in the electrode material, leading to a decrease in the charging efficiency of the battery and a longer charging time.
Conclusion
To mitigate the impact of high temperatures on lithium-ion batteries, proper storage, and usage are crucial. It is recommended to keep the batteries in a cool and dry place, away from direct sunlight, and avoid exposing them to high temperatures for extended periods. When using electronic devices, it is best to avoid charging the batteries under direct sunlight or in hot environments.
