Three-dimensional phloretin-functionalized graphene aerogel for high-performance supercapacitors and phase change materials

Graphene aerogels have attracted considerable attention owing to their significantly higher electrical and thermal conductivity compared with conventional materials. To further enhance the surface functionality of graphene aerogels, we prepared three-dimensional multi-functional aerogels via hydrothermal treatment and freeze-drying using natural green organic small-molecule compound phloretin and graphene oxide. This aerogel has excellent electrochemical properties, with a specific capacitance as high as 433 F g-1 (at a current density of 1 A g-1). In addition, symmetrical supercapacitors (SCs) assembled with this electrode material exhibit excellent energy storage performance with an energy density of 13.33 W h kg-1, power density of 399.9 W kg-1 and capacitance retention rate of 88% after 10 000 cycles. Furthermore, a phase change material prepared using the aerogel and pure paraffin wax shows significantly higher energy conversion efficiency than sole paraffin wax and exhibits good thermal stability. Overall, owing to its unique physicochemical properties and environmental friendliness, the prepared multi-functional aerogel has good application prospects in the fields of SCs and thermal management.