In-situ study of mechano-electrochemical coupling properties of symmetrical SnO2/Gr electrodes for lithium-ion batteries using digital image correlation

SnO 2 /Gr composite as anode material for lithium-ion batteries was synthesized by an acoustic-chemical method followed by an annealing treatment. The composite exhibits high crystallinity and purity, and the weight ratio of SnO 2 is controllable. Benefit from the compound effect between material components, the SnO 2 /Gr anodes give notable reaction kinetics and cycling stability. The specific capacity of the composite with 27.4 wt% SnO 2 remains 649.9 mA h g −1 after 170 cycles at 200 mA g −1 . The strain field features in the symmetrical SnO 2 /Gr electrodes were in-situ measured during electrochemical cycles by digital image correlation technique . The distribution and variation characterizations of diffusion induced stress in the symmetrical SnO 2 /Gr electrodes were obtained by using mechano-electrochemical coupling constitutive equation. Furthermore, the contributions of the electrochemical and mechanical stress parts to the plane stress in the symmetrical SnO 2 /Gr electrodes also be discussed, respectively. The results and analytical method are critical for further revealing the failure mechanism and optimizing architecture of the SnO 2 /Gr electrodes for lithium-ion batteries.