Thermally insulating and fire‐retardant bio‐mimic structural composites with a negative Poisson's ratio for battery protection

Abstract Battery safety has attracted considerable attention worldwide due to the rapid development of wearable electronics and the steady increase in the production and use of electric vehicles. As battery failures are often associated with mechanical‐thermal coupled behaviors, protective shielding materials with excellent mechanical robustness and flame‐retardant properties are highly desired to mitigate thermal runaway. However, most of the thermal insulating materials are not strong enough to protect batteries from mechanical abuse, which is one of the most critical scenarios with catastrophic consequences. Here, inspired by wood, we have developed an effective approach to engineer a hierarchical nanocomposite via self‐assembly of calcium silicate hydrate and polyvinyl alcohol polymer chains (referred as CSH wood). The versatile protective material CSH wood demonstrates…