In-situ strain characterization and stress analysis of SnO2@graphite@CNT electrodes for lithium-ion batteries by digital image correlation method

In this study, SnO2@graphite@CNT composite was synthesized by growing SnO2 nanoparticles within the interconnected three-dimensional network of graphite and carbon nanotubes using an acoustic chemistry method and a followed annealing treatment. As anode material for lithium-ion batteries, the composite exhibits high specific capacity and excellent cycling stability. The deformation behavior of the SnO2@graphite@CNT electrodes was in-situ monitored and recorded during discharge-charge process, and the strain fields onto the electrode surface was analyzed using digital image correlation technique. The dynamic evolution of plane stress in the electrode was evaluated by combining strain data with a mechano-electrochemical constitutive equation, and the contributions of mechanical and electrochemical parts to the plane stress also be discussed, respectively. The results provide valuable insights into the volume deformation behavior and mechano-electrochemical failure mechanism of SnO2-based electrodes for lithium-ion batteries.