Scalable Polymer-Infiltrated Boron Nitride Nanoplatelet Films with High Thermal Conductivity and Electrical Insulation for Thermal Management

The development of thermally conductive polymer composites (TCPCs) of high filler loads holds great promise for thermal management in electronics and power systems. However, achieving high filler loads in TCPCs is still a great challenge because of the processing difficulties for the traditional melt blending or solution mixing methods. Herein, we proposed a scalable methodology to fabricate high-performance polymer-infiltrated boron nitride nanosheet (BNNS) composite films embedded with high filler loads for efficient thermal management. The polymer-infiltrated BNNS films exhibited excellent heat conduction performance, and the maximal in-plane thermal conductivity was as high as 20.65 W/(m·K), which was increased by 258% compared to that of the conventional BNNS/PU films with the identical BNNS content. Moreover, the polymer-infiltrated BNNS films also showed high electrical insulation, good mechanical performance, and excellent thermal stability. More importantly, the polymer-infiltrated BNNS films were demonstrated to have strong heat dissipation capability for thermal management in high-power light-emitting diode modules and power batteries. The findings provide valuable guidance for developing advanced TCPCs with high filler loads for thermal management.