Structurally Tailored Boron Nitride Networks With Pore‐Engineered and Interfacial Compatibility for Highly Thermally Conductive Epoxy Composites

ABSTRACT The rapid advancement of artificial intelligence technology has driven continuous enhancement in chip power density, making thermal management of high‐power components a critical challenge constraining reliability and energy efficiency improvement. However, the micro‐nano interfacial mismatch in boron nitride (BN)/polymer composites has restricted their broader application in thermal management. In the present work, an epoxy resin composite with adjustable pore structure and designed functionalization of BN nanosheets (FBN) was fabricated by pre‐freezing regulation‐ice templating strategy. Benefiting from the optimization of FBN interface compatibility and the regulation of three‐dimensional (3D) pore structure, the epoxy resin/FBN (EBN) composite exhibits highly through‐plane thermal conductivity of 3.07 W m ⁻¹ K ⁻¹ with 7 wt% FBN loading, representing a 13‐fold enhancement over pure epoxy, while maintaining robust mechanical properties with a compressive strength of 93 MPa. The radial rapid‐freezing method induced the self‐organization of FBN fillers into well‐aligned interpenetrating networks, substantially maximizing interfacial contact between fillers and enabling optimized directional heat flux transfer. Furthermore, finite element simulations confirm the exceptional thermal transfer capability of EBN composites in practical applications, highlighting their suitability for thermal management in highly integrated electronic devices. This study offers novel design strategies for advanced thermal interface materials in next‐generation devices.