In-operando deformation studies on the mechano-electrochemical mechanism in free-standing MWCNTs/V2O5 lithium ion battery electrode

Free-standing MWCNTs/V2O5 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 V2O5 cathodes. The distribution and evolution features of plane strains in free-standing MWCNTs/V2O5 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/V2O5 electrode is confirmed via nanoindentation. The evolutions of average plane stresses in the free-standing MWCNTs/V2O5 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. (C) 2019 Elsevier Ltd. All rights reserved.