热扩散对Li电池空心球形颗粒电极的影响  

Effects of thermal diffusion in hollow lithium ion battery with spherical particle electrode

作　　者：陈兵兵[1] 周剑秋[1] 刘振[1] 

机构地区：[1]南京工业大学机械与动力工程学院,江苏南京211800

出　　处：《南京工业大学学报（自然科学版）》2016年第3期1-7,共7页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：国家自然科学基金(10872087);江苏省科技支撑计划(BE2009170);湖北省优秀中青年人才项目(Q20111501);霍英东青年教师基金(101005)

摘　　要：空心球体模型被用来研究热扩散机制对空心球形纳米颗粒电极中应力变化的影响。在锂化过程中,电极材料的体积膨胀和应力变化将随着载荷和热扩散的变化而变化。随着温度的增加,径向应力的中间区域变化明显,而环向应力在空心球形电极的内部和外部的部分变化明显。当最大拉伸环向应力热量的减少量比临界断裂强度大得多时,可能会发生裂纹形核和断裂。因此电极充放电过程中的浓度和温度的变化对电极材料的扩散应力产生重要的影响。A new hollow spherical model was established to account for thermal diffusion effect on hollow electrode,focusing on the effect of the mechanism of temperature on stress variation in the hollow spherical nanoparticles electrode. Concentrated load and heat caused the volume expansion with the radius changing. With the increase of temperature,the radial stress changed significantly in the middle area,while the hoop stress changed obviously in the both internal and external part of the hollow spherical electrode.When the maximum tensile ring＇ s reduction of heat stress was much larger than the critical fracture strength,crack nucleation and fracture might occur. A combination of concentration and temperature stress intensity was considered as an important factor for electrode material.

关 键 词：Li离子电池 扩散应力 热扩散 空心球形颗粒 

分 类 号：TM912[电气工程—电力电子与电力传动]