▎ 摘　　要

Efficient heat dissipation is essential for further improving the integration of high-power electronic packaging equipment. Through-plane direction aligned three-dimensional boron nitride nanosheets/graphene(3D-BNNS/ Gr) aerogels are designed as heat transferring skeletons for epoxy nanocomposites. Graphene was in-situ synthesized on BNNS by a combustion synthesis method to ensure good contact, and subsequent aligning of BNNS/ Gr nanofillers by a self-assembly ice-templating strategy to reduce contact resistance between individual BNNS. At a relatively low 3D-BNNS/Gr loading of 11.2 vol%, the composites exhibit superior through-plane thermal conductivities of 2.23 and 1.09 W m(-1) K-1, demonstrating a 1073% and 1069% thermal conductivity enhancement at room temperature (RT) and liquid nitrogen temperature (77 K) compared with pure epoxy resin. Meanwhile, the mechanical properties of the composites at RT and 77 K were synchronously enhanced. Furthermore, the 3D-BNNS/Gr-epoxy nanocomposite film then acts as a heat spreader for heat dissipation of high-power LED modules and exhibits superior cooling efficiency.