超声检测技术用于评估锂离子电池的荷电状态和健康状态,受到了广泛的关注,但是在大倍率、高温升条件下电池声学响应特征及放电条件与声学信号的关系尚不清楚.基于以上问题,通过搭建磷酸铁锂电池电-声-热综合检测平台,分析电池超声信号温度作用机制,引入与荷电状态相关的温度耦合系数以实现声学传播特性的温度解耦,并分析了不同温度和放电倍率下锂离子电池循环过程中的声学响应特性.实验结果表明,解耦温度的声学时域特征能够准确表征电池内部结构变化,为磷酸铁锂电池的检测和超声技术用于更多场景提供了研究方法.
Ultrasonic analysis has been widely used to evaluate the state of charge and health of lithium ion batteries,but the relationship between acoustic response characteristics and dis-charge conditions and acoustic signals under high magnification and high temperature rise is still unclear.Based on the above problems,this paper analyzes the temperature mechanism of the ultrasonic signal of the battery by building the electric-acoustic-thermal integrated detec-tion platform for lithium iron phosphate battery,introduces the temperature coupling coeffi-cient related to the state of charge to realize the temperature decoupling of the acoustic propaga-tion characteristics,and also analyzes the acoustic response characteristics of the lithium ion battery during the cycle at different temperatures and discharge rates.The experimental results show that the acoustic time domain characteristics of decoupling temperature can accurately characterize the internal structure changes of the battery,which provides a research method for the detection of lithium iron phosphate battery and ultrasonic technology for more scenes.