Flexible insulating phase change composite film with improved thermal conductivity for wearable thermal management

Phase change materials (PCMs) are extensively employed as media for thermal energy storage and temperature regulation due to their remarkable capacity to absorb or release significant amounts of latent heat at constant phase transition temperatures. However, the inherent low thermal conductivity, solid-state rigidity and electric insulation issues of PCMs greatly limit their practical applications in the field of wearable thermal management of flexible electronic devices. Herein, we have developed a flexible composite PCM film with improved thermal conductivity by incorporating paraffin wax (PW) with a porous structure of polyvinylidene fluoride-boron nitride (PVDF-BN) film as a substrate. Remarkably, the composite film exhibits outstanding electric insulation properties and excellent cycle stability, further enhancing its suitability of thermal management in wearable electronics for safe and long-term applications. The obtained flexible composite PCM film exhibits a superior melting enthalpy of 105.63 J·g−1, along with a 200% improvement in thermal conductivity compared to the pure PW. Furthermore, this flexible composite film can not only retain its remarkable flexibility at room temperature but also demonstrate attractive shape recovery capabilities during phase transition process. The flexible insulating PCM film developed in this work may hold substantial promise for applications in the field of wearable thermal management for next-generation electronic devices.