循环充放电条件下锂离子电池的温度模拟

摘要

The heat generation for lithium-ion batteries is composed of the reversible heat caused by the electrochemical reaction and the irreversible heat due to polarization during charge-discharge cycling. The materials of cobalt acid lithium battery begin to decompose once the internal temperature of the battery reached 82oC. A series of uncontrolled chemical reactions are triggered, resulting in releasing a large amount of heat. With the aid of finite element technology, the reversible, irreversible heat and the decomposition heat are both considered in this work to simulate the internal temperature variation of lithium-ion batteries under different cooling conditions and ambient temperatures, which can provide theoretical basis to disclose the thermal runaway mechanism for this kind of battery.%锂离子电池在充放电过程中产生的热量主要为两部分，即因电化学反应而产生的可逆热和由极化产生的不可逆热。若电池内部温度达到82℃以上时，钴酸锂电池材料将发生热分解，引发一系列不可控化学反应，释放出大量的反应热。本论文在可逆热和不可逆热的基础上，耦合电池材料分解热，采用有限元技术，模拟锂离子电池在充放电过程中不同对流条件以及不同外界温度下电池内部温度的变化，为揭示锂离子电池热失控机制提供理论依据。