Deformation and failure behaviors of anode in lithium-ion batteries: Model and mechanism

Deformation and failure behaviors of the anode material play important roles in internal short-circuit and thermal runaway behaviors of lithium-ion batteries. In previous research, we discovered that anode behaves significantly different in constitutive behaviors at various strain rates. To unravel the fundamental mechanism, a multiscale detailed computational model describing anode behavior is established in the present study. Numerical simulation results of anode material show that the established model has a good correlation with the experiments for the description of the mechanical behaviors of the anode at strain-rates from 5 × 10⁻⁴/s to 1 × 10⁻¹/s. This model shows that the high strain-rate dependency of the failure of the active material should be responsible for the observed deformation behavior of the anode material. Meanwhile, it is found that the particle size distribution and mechanical properties of the binder have an influential effect on the yield strength value of the anode. Results clarify the fundamental reasons for the behaviors of anode material, which may support the design of safer and more robust batteries.