In-operando deformation studies on the mechano-electrochemical mechanism in free-standing MWCNTs/V ₂ O ₅ lithium ion battery electrode

Free-standing MWCNTs/V ₂ O ₅ nanobelts composite architecture electrodes for lithium ion batteries (LIBs) are prepared based on hydrothermal method, electrostatic self-assembly approach and vacuum filtration deposition technique. Such kind of nanoarchitecture enhances the electrochemical kinetics and structural stability of V ₂ O ₅ cathodes. The distribution and evolution features of plane strains in free-standing MWCNTs/V ₂ O ₅ cathodes surface are in-operando monitored by using digital image correlation method and systematically discussed. The strain results show that the evolution of strain against potential obeys general Arrhenius relation under galvanostatic charge-discharge cycling. Considering the effect of lithium ion concentration, the elastic modulus of 20 wt% MWCNTs/V ₂ O ₅ electrode is confirmed via nanoindentation. The evolutions of average plane stresses in the free-standing MWCNTs/V ₂ O ₅ electrodes, as well as the contributions of mechanical and electrochemical components, are evaluated and discussed by mechano-electrochemical constitutive equation during electrochemical process. The analytical methods used in this article are universal for revealing the electrode mechano-electrochemical failure mechanism in LIBs.