Ultra-high thermal conductivity multifunctional composites with uniaxially oriented boron nitride sheets for future wireless charging technology
Yiwei Zhou, Yandong Wang, Maohua Li, Yue Qin, Rongjie Yang, Kang Xu, Yingying Guo, Linhong Li, Zhenbang Zhang, Jianxiang Zhang, Boda Zhu, Cheng‐Te Lin, Yixiang Xu, Kazuhito Nishimura, Nan Jiang, Jinhong Yu
Abstract
The rapid advancement of wireless charging systems (WCSs), fifth-generation (5G) technology, electric vehicles (EVs), and artificial intelligence (AI) systems result in a critical need for more efficient thermal management materials. h-BN, characterized by its ultra-high theoretical thermal conductivity and excellent electrically insulating properties, serves as a promising filler for blending with polymers to develop high-performance thermally conductive composites. However, it is still a challenge to attain a high through-plane thermal conductivity of over 40 Wm −1 K −1 at filler content at 80 vol%. This persistent limitation is mainly attributed to the fact that most current h-BN used in the manufacture of thermal conductive composites has relatively smaller lateral size (below 40 µm). Additionally, the effective orientation strategy (e.g., ice-template strategy) usually results in difficulties in mass production. Here, a two-step process involving blade coating and lamination is used to prepare BN/TPU composites with an through-plane thermal conductivity of 43 Wm −1 K −1 at h-BN content of 67 vol%. With upper-level electric insulating properties and wave-transparent characteristic, the multifunctional BN/TPU composite shows excellent thermal management ability in the high-power wireless charging area and also has the potential to be used in the 5G communication technology field.