Anisotropic graphene films with improved thermal conductivity and flexibility for efficient thermal management

Abstract

The rapid development of miniaturization and densification of electronic devices brings substantive needs for highly thermally conductive and flexible thermal interface materials (TIM) to ensure service reliability and prolong the lifetime of electronic components. Herein, we proposed highly thermally conductive and flexible graphene (Gr) films by a vacuum-assisted filtration strategy. Driven by the strong vacuum shear force and the dispersing effect of Polyvinyl pyrrolidone (PVP), the Gr sheets stacked layered-by-layered owing to hydrogen bond (H-bond). The highly laminated Gr/PVP films (GPVP-F) exhibited high in-plane thermal conductivity of 81.2 W m−1 K−1 and through-plane thermal conductivity of 5.1 W m−1 K−1. In actual applications, the GPVP-F cooled the light-emitting diode (LED) chip by 4.3 °C (from 46.1 °C to 41.8 °C) when being used as flexible TIM, which was at an advanced level for room-temperature device (＜ 50 °C) cooling. Besides, GPVP-F still performed excellent thermal conductivity (68.1 W m−1 K−1) even at 100 °C and splendid stability after 10 times of heating-cooling cycles. More importantly, the meritorious flexibility ensured GPVP-F being capable of applying in the device with irregular shapes. All the above results bring GPVP-F a promising prospect in thermal management of electronic devices.