Strong dependency of lithium diffusion on mechanical constraints in high-capacity Li-ion battery electrodes

作     者：Yi-Fan Gao Min Zhou 

作者机构：The George W. Woodruff School of Mechanical EngineeringThe School of Materials Science and EngineeringGeorgia Institute of Technology Atlanta GA30332-0405 USA WCU Program on Multiscale Mechanical DesignSchool of Mechanical and Aerospace EngineeringSeoul National University Seoul Korea 

出 版 物：《Acta Mechanica Sinica》 (力学学报（英文版）)

年 卷 期：2012年第28卷第4期

页      面：1068-1077页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 0808[工学-电气工程] 08[工学] 

基　　金：supported by the National Research Foundation of Korea through WCU(R31-2009-000-10083-0) 

主　　题：Li-ion battery - Inelastic flow Lithiation in- duced softening Changing rate 

摘      要：The effect of external constraints on Li diffusion in high-capacity Li-ion battery electrodes is investigated using a coupled finite deformation theory. It is found that thinfilm electrodes on rigid substrates experience much slower diffusion rates compared with free-standing films with the same material properties and geometric dimensions. More importantly, the study reveals that mechanical driving forces tend to retard diffusion in highly-constrained thin films when lithiation-induced softening is considered, in contrast to the fact that mechanical driving forces always enhance diffusion when deformation is fully elastic. The results provide further proof that nano-particles are a better design option for nextgeneration alloy-based electrodes compared with thin films.