A multiphysics electrochemical–thermal–mechanical model for predicting the lifetime and degradation pathways of hierarchical Co3O4/graphene anodes in sustainable lithium-ion batteries

Abstract

The sustainable advancement of lithium-ion batteries relies on understanding and mitigating degradation in high-capacity anodes. This study develops a coupled electrochemical–thermal–mechanical model to elucidate the degradation behavior of hierarchical Co₃O₄/graphene anodes. Using COMSOL Multiphysics® software, lithium diffusion, stress evolution, Joule heating, and solid electrolyte interphase (SEI) growth were simultaneously simulated to capture their complex interdependence. Results indicate that repeated cycling generates localized temperature rises of up to 12 °C and mechanical stresses exceeding 100 MPa, which accelerate SEI thickening and interfacial resistance growth. A novel Anode Lifetime Index (ALI) was introduced to quantify cumulative degradation by integrating mechanical and interfacial variables over time. Sensitivity analyses revealed that thinner electrodes (20–40 µm) and optimized Co₃O₄/graphene ratios (0.7–0.8) enhance durability, reducing lifetime degradation by up to 40%. The model accurately reproduces experimental electrochemical trends, validating its predictive capability. This integrated framework provides a powerful tool for designing thermally and mechanically stable oxide-based anodes. By linking fundamental multiphysics mechanisms with macroscopic lifetime prediction, the study contributes to the rational design of durable, safe, and energy-efficient lithium-ion batteries aligned with sustainable energy goals.