A Low-Temperature Heat Output Photoactive Material-Based High-Performance Thermal Energy Storage Closed System

Designing and synthesizing photothermal conversion materials with better storage capacity, long-term stability as well as low temperature energy output capability is still a huge challenge in the area of photothermal storage. In this work, we report a brand new photothermal conversion material obtained by attaching trifluoromethylated azobenzene (Azo(F)) to reduced graphene oxide (rGO). Azo(F)-rGO exhibits outstanding heat storage density and power density up to 386.1 kJ·kg(−1) and 890.6 W·kg(−1), respectively, with a long half-life (87.7 h) because of the H-bonds based on high attachment density. Azo(F)-rGO also exhibits excellent cycling stability and is equipped with low-temperature energy output capability, which achieves the reversible cycle of photothermal conversion within a closed system. This novel Azo(F)-rGO complex, which on the one hand exhibits remarkable energy storage performance as well as excellent storage life span, and on the other hand is equipped with the ability to release heat at low temperatures, shows broad prospects in the practical application of actual photothermal storage.