Bio-inspired honeycomb core integrated into fiber metal laminates for enhanced impact resistance of lithium-ion battery modules: A numerical study

Ensuring the mechanical safety of lithium-ion batteries is a critical challenge in the electric vehicle industry, particularly under high-velocity impact scenarios. This study proposes a novel protective structure by integrating bio-inspired honeycomb cores into fiber metal laminates (FMLs). Using a validated LS-DYNA finite element (FE) framework, the crashworthiness of a battery-integrated FML panel was investigated under intermediate-velocity impact. Eight distinct core topologies – including regular hexagonal and seven bio-inspired designs, such as Spider, Snail, and Grass Stem – were rigorously evaluated under equal geometric constraints. The results demonstrated that bio-inspired architectures significantly outperform conventional designs in mitigating impact energy. Most notably, the Grass Stem configuration emerged as the superior design, achieving a 24.09% reduction in central battery deformation compared to the baseline, effectively maintaining the cell compression below the critical safety threshold of 4 mm. While designs like Snail and Hierarchical also met safety criteria, the Grass Stem topology offered the optimal balance between mass efficiency and structural protection. These findings provide a concrete engineering guideline for the design of next-generation, lightweight, and impact-resistant battery housings.