Fracture predictions based on a coupled chemo-mechanical model with strain gradient plasticity theory for film electrodes of Li-ion batteries

• Published in: Engineering fracture mechanics Vol. 253; p. 107866
• Main Authors: Chen, Yaoxing, Sang, Mengsha, Jiang, Wenjuan, Wang, Yan, Zou, Youlan, Lu, Chunsheng, Ma, Zengsheng
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.08.2021; Elsevier BV
• Subjects: Concentration gradient; Deformation; Diffusion effects; Diffusion-induced stress; Dislocation density; Elastoplasticity; Electrode materials; Finite element model; Interfacial damage; Li-ion battery; Lithium-ion batteries; Plastic properties; Rechargeable batteries; Size effects; Strain; Strain gradient plasticity; Substrates; Thickness; Diffusion-induced stress; Finite element model; Strain gradient plasticity; Interfacial damage; Li-ion battery
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/j.engfracmech.2021.107866

Schematic of a film electrode on a rigid substrate subject to Li+ insertion [Display omitted] •A model coupling the electrochemical reaction with strain gradient plasticity is developed.•The evolution and distributions of electrochemical-reaction dislocations are analyzed.•High-density dislocations can induce high stresses at the lithiation front.•This model could predict the damage and fracture of the electrode interface. High-capacity electrodes in Li-ion batteries inevitably undergo a large volume deformation originating from high diffusion-induced stresses during charging and discharging processes. In this paper, we firstly develop a new elastoplastic model for describing diffusion-induced deformation in the framework of high-density dislocation defects generated due to the migration of Li atoms. Then, we analyze the film size effect, diffusion-induced stress, plastic yielding, and hardening of electrode materials based on the evolutions of Li concentration by a strategy combining the strain gradient plasticity theory and finite element simulations. Finally, according to the traction-separation law, interface damage and debonding are characterized in the active film materials (with a thickness of 150, 200, and 250 nm, respectively) on a rigid substrate.