Structurally engineered 3D porous graphene based phase change composite with highly efficient multi-energy conversion and versatile applications

Micro-nano encapsulation strategy combining three-dimensional (3D) porous carriers and phase change materials (PCMs) has been widely investigated due to its structure stability, high efficiency, and designability. However, the current 3D scaffolds suffering from structure regularity are hard to meet the urgent requirements of high energy conversion efficiency and versatile applications. Herein, a 3D porous graphene scaffold (2LrGO@LIG), which is fabricated from polybenzoxazine/graphene oxide (GO) composite using laser irradiation that structurally engineers a gully-shaped surface and a 3D overlapped graphene networks, was employed for PCMs encapsulation. The addition of GO is proved to enhance the quality of produced laser induced graphene (LIG), which could also be reduced into laser-reduced graphene oxide (LrGO) and connect the adjacent LIGs as thermal bridges. As a consequence, the obtained phase change composite (2LrGO@LIG/MA) showed photo-thermal and electro-thermal conversion efficiency of 94.1 % and 99.1 %, respectively. In addition, benefiting from the surface hydrophobicity (135°), high energy storage density (167.7 J/g) and electrical conductivity (307.9 S/m), 2LrGO@LIG/MA also demonstrated great potential in smart building materials and wearable electronic devices. This study provides a facile method for designing advanced PCM composites with multi-energy conversion capacity and application versatility. [Display omitted] •A 3D porous graphene scaffold with a gully-shaped surface and enhanced networks is employed for PCMs encapsulation.•In-situ reduced LrGO connects adjacent LIG sheets and improves LIG quality.•A high energy density (167.7 J/g) and extraordinary solar-/electro-thermal conversion efficiencies (94.1 % and 99.1 %) are realized.•2LrGO@LIG/MA with self-cleaning and EMI shielding abilities exhibits potential applications in construction materials and wearable electronic devices.