Rate-dependent stress evolution in nanostructured Si anodes upon lithiation

Zheng Jia, Wing Kam Liu, Rate-dependent stress evolution in nanostructured Si anodes upon lithiation, Applied Physics Letters, 109, 163903 (2016) (DOI:http://dx.doi.org/10.1063/1.4964515)

Development of stresses and fracture in Si-based anodes for lithium-ion batteries are strongly affected by lithiation-induced plasticity. Recent experiments indicate that the nature of plasticity of lithiated silicon is rate-dependent. We establish a theoretical model to capture the viscoplastic mechanical behavior of Si anodes during two-phase lithiation. It is demonstrated that the lithiation-induced stress field is determined by the migration speed of the Li-Li3.75 Si interface and the characteristic size of the Si anodes. If experimentally measured interface velocity data in Si nanoparticle is available, the mechanistic model can directly predict the rate-sensitive spatiotemporal stress profile, which is hardly measured in experiments.