As the core component of the energy storage system, the safe operation of the lithium battery is extremely important. However, the temperature rise during the discharge process will seriously affect battery safe operation and cycle life, and even lead to accidents. Therefore, it is necessary to study the influence of the working temperature of lithium batteries on safety.
1. During a single charge-discharge cycle of a lithium battery, when the charging rate remains unchanged, as the discharge rate increases, the maximum temperature of the lithium battery is also increasing. Heat dissipation measures need to control the temperature no more than the highest ideal operating temperature.
2.Under the constant current discharge of different currents, the heat generation power of the lithium battery is not the same, and its maximum temperature is also different. From the inner center of the lithium battery to the four corners, the temperature gradually decreases.
3.Under normal temperature 25℃, charging rate 0.5C, and natural heat dissipation, when the lithium battery performs a single charge-discharge cycle, the discharge rate within the ideal operating temperature range shall not exceed 1.50 C. When the lithium battery discharge rate exceeds 2.74 C, the maximum temperature of the battery to complete a single charge-discharge cycle will exceed the safety limit. Therefore, to prolong the service life of lithium batteries, the discharge rate needs to be controlled within a reasonable range.
4.In addition to changing the discharge rate of the lithium battery, the external ambient temperature is also one of the significant factors affecting the internal thermal environment during continuous charge-discharge cycles. To maintain the temperature of the lithium battery within the ideal operating range, it is necessary to continuously reduce the external temperature through ventilation and heat dissipation when the discharge rate of the lithium battery increases uniformly. And the lithium battery can continue to work.