锂离子电池三维层级循环寿命对应关系研究

The corresponding relationship of cycle life for LIB from three-dimensional

动力电池寿命极大程度上影响电动汽车使用寿命,是决定车辆经济效益的重要因素。除已有研究的单体寿命外,模组和电池系统寿命接近整车使用状态,更具有研究意义。在电池单体基础上,增加模组和电池系统,率先构建单体-模组-电池系统三维层级。以锰酸锂软包单体电池为最小电池单元,研究以此构成的两个型号、三维层级间电池循环老化过程中电化学特性、容量衰减和循环温度变化情况。结果表明,特定冷却环境下,在循环容量衰减方面,三个层级间关系为电池系统衰减>模组衰减>单体衰减;在循环温度方面,模组温度>单体温度>系统温度。电池三维层级关系构建的结果,说明了循环容量衰减和循环温度两方面的层级间构效关系,为锰酸锂动力电池体系循环老化过程研究提供参考。

Cycle life of power batteries greatly affects the service life of electric vehicles,which is an important factor of economic benefits.In addition to the cycle life studies of lithium-ion battery cells,the cycle life of module and battery system is more significative due to they are close to practical application.In this paper,using lithium manganate pouch cells as smallest testing unit,the electrochemical characteristics,capacity attenuation and temperature variation of monomer-modulebattery system are systematic analyzed.Results show that in the cooling condition,the relationship among the attenuation of three levels is battery system>module>cell;in terms of cycle temperature,module>cell>system.The results of three-dimensional hierarchical relationship illustrate the interfacial structure-activity relationship in capacity attenuation and temperature variation,which provides a reference for the study of cycle aging process of lithium traction battery system.