Preparation of phase change material filled hybrid 2D/3D graphene structure with ultra-high thermal effusivity for effective thermal management

Graphene-based energy storage and renewable material has increasingly attracted research interest, due to its high thermal conductivity and light weight. Researchers fill phase change material (PCM) into three-dimensional graphene foam, to obtain a composite with high energy storage capability and moderate thermal conductivity. However, this kind of composite's heat transfer mode is single and cannot maximize the advantages of graphene. Herein, a stearic acid filled graphene-foam composite (GFSAC) connected with graphene paper (GP) through gravity-assisted wetting attaching process is demonstrated in this paper. GP is obtained by thermal reduction of graphene oxide (GO) paper. Its in-plane thermal conductivity can reach up to 938 Wm(-1) K-1. By controlling the preparation process of GO paper, the in-plane thermal conductivity of GP can be adjusted. GFSAC is consisted of GF and SA, GFSAC with different heat transfer properties can be prepared by adjusting the degree of reduction of GF. A novel gravity-assisted wetting attaching process has been developed to prepare GP/GFSAC/GP composite, which can effectively reduce the thermal resistance between GP and GFSAC. The effective thermal effusivity of the final GP/GFSAC/GP composite reaches 18.45 J cm(-3/2) m(-1/2) s(-1/2) K-1/2, showing an excellent thermal management capability. (C) 2021 The Authors. Published by Elsevier B.V.