Fracture damage of nanowire lithium-ion battery electrode affected by diffusion-induced stress and bending during lithiation

Abstract

Lithium-ion battery electrode materials generally experience significant volume changes during lithium diffusion in charging and discharging. These volume changes lead to diffusion-induced stress and defect nucleation. By analyzing the stress, the bending associated with lithiation, we find that size reduction of the electrode can avoid the phenomenon of volume change. In this work, we build a relationship among the stress, bending, strain energy and size of the electrode. Also, the fracture energy of the electrode materials, which can be evaluated further by the strain energy, has been derived to optimize the electrode size for maximizing the battery life. Finally, a critical electrode size determination method is proposed.