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, heat transfer mode of this kind of composite 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. The GP/GFSAC/GP composite possesses a high thermal conductivity of 1.72 Wm(-1)K(-1) (with 0.53 wt % graphene loading), and an excellent effective thermal effusivity of 18.45 Jcm(-3/2)m(-1/2)s(-1/2)K(-1/2). The GP/GFSAC/GP composite is shown to be an ideal material for thermal energy storage and renewable. Additionally, the low thermal resistance connection is achieved between 3D GFSAC and 2D GP, which plays a key role in the improvement of the composite's thermal effusivity. Compared to other samples, the maximum temperature of the GP/GFSAC/GP composite is significantly lower and its temperature uniformity is much better, under the same heating condition. More importantly, after stop heating, the GP/GFSAC/GP composite shows the best temperature maintenance capacity. (C) 2020 Elsevier Ltd. All rights reserved.