One-Step Synthesis of Tough and Superelastic Ceramic Fibrous Sponges for Battery Thermal Runaway Protection

The escalating risk of thermal runaway propagation poses a major challenge for high-energy-density lithium-ion battery modules. Current passive thermal protection materials struggle to combine robust mechanical resilience with exceptional thermal insulation. Herein, we present a one-step, dual-templating electrospinning strategy inspired by the interwoven and curling structure of pumpkin vines to directly synthesize centimeter-thick, superelastic ceramic fibrous sponges. These sponges, composed of hierarchical micro-belt and submicro-fiber assemblies, exhibit outstanding compression resilience (>80%) across a wide temperature range from −196°C to 1100°C, alongside excellent shape adaptability. Their hierarchical porosity yields a low thermal conductivity of 31.98 mW·m⁻¹·K⁻¹. Consequently, a mere 3-mm-thick sponge layer can effectively quench the thermal runaway propagation in a high-energy battery module assembled from four 55Ah individual cells, delaying propagation by 729 s—a critical time window for emergency response. This work establishes a new paradigm for fabricating tough, superelastic ceramics, showcasing immense potential for safe battery design and thermal management in extreme environments.