温度自适应的锂离子电池低温自加热方法

Temperature-adaptive internal heating strategy for lithium ion battery at low temperature

低温下锂离子电池峰值功率和可用能量急剧下降,且难以充电,已成为制约电池应用的瓶颈之一。基于等效电路模型构建电池温升模型,从缩短加热时间和避免电压超限两个方面分析了加热电流幅值和频率的选取原则,提出了随温度自适应调整脉冲电流幅值的低温自加热方法。该方法可在7 min内将电池均匀地从-10.5℃加热到1.4℃,温升速率为1.7℃/min,验证了模型的准确性,加热后电池可充入更多的电能,有助于解决低温下电池性能差、充电难等问题。

The peak power and available energy of lithium ion batteries are decreased significantly at low temperatures,which has been one of the bottlenecks of battery applications in the cold climate.Based on the first-order RC equivalent circuit model,the lumped temperature-rise model is developed.The heating time and battery voltage limitation are carefully considered when selecting amplitude and frequency of pulse current.A novel temperature-adaptive internal heating strategy based on stepwise increasing pulse charge-discharge current is proposed to enhance battery performance at low temperature.The battery can be uniformly heated from-10.5℃to1.4℃within 7 min,with the average temperature-rise rate of 1.7℃/min,implying the accurate simulation model.The charging performance of the battery after heating is significantly improved.The experimental and simulation results show that the proposed heating method can quickly heat the battery to a proper temperature,contributing to rapidly improve battery performance at low temperature.