Tunable Diffusion-Induced Stresses in Bilayer Li-Based Battery Electrodes with Graphene Origami-Enabled Auxetic Metamaterial Current Collectors

Lithium-based batteries face critical challenges from diffusion-induced stresses (DIS) and bending deformations in bilayer electrodes, both arising from lithium-ion intercalation and deintercalation, which limit cycle life and energy density. This study introduces, for the first time, a graphene origami (GOri)-enabled copper matrix auxetic metamaterial as a tunable current collector to mitigate these issues. By exploiting the origami-induced negative Poisson’s ratio (NPR), tunable through the GOri folding degree and graphene content, the design promotes synclastic deformation and efficient load transfer, thereby alleviating stress concentrations. The effective properties of the GOri/Cu metamaterial (Young’s modulus, Poisson’s ratio and density) were predicted using a genetic programming-assisted micromechanical model. Analytical solutions based on classical thin-plate theory were then developed to quantify DIS and curvature evolution under galvanostatic and potentiostatic charging, with lithium concentration fields governed by Fick’s law. Numerical results reveal the peak interfacial compressive stress in the active layer decreases by 26%, tensile stress in the collector by 20% and electrode curvature by 15% compared with pristine Cu. These enhancements are achieved without compromising conductivity, while delivering a 12% lighter electrode and improved resistance to delamination and fracture. This auxetic strategy not only advances current collector design but also enables high-performance lithium batteries with extended cycle life, offering a scalable pathway toward next-generation energy storage.