A study of lithium ion intercalation induced fracture of silicon particles used as anode material in Li-ion battery

Abstract

The fracture of Si particles due to internal stresses formed during the intercalation of lithium ions was described by means of thermal analogy model and brittle fracture damage parameter. The stresses were calculated following the diffusion equation and equations of elasticity with appropriate volumetric expansion term. The damage parameter takes into account triaxiality of the stress state and change in elasticity upon tension and compression, and represents the probability of fracture under given stress state, - an approach suitable for brittle materials. The results were compared with the acoustic emission data from the experiments on electrochemical cycling of Li ion half-cells with silicon electrodes. A good correlation between experiment and prediction was observed.