RESUMO
Novel 2D material-based supercapacitors are promising candidates for energy applications due to their distinctive physical, chemical, and electrochemical properties. In this study, a dandelion-like structure material comprised of Sm2O3, Co3O4, and 2D reduced graphene oxide (rGO) on nickel foam (NF) was synthesised using a hydrothermal method followed by subsequent annealing treatment. This dandelion composite grows further through the tremella-like structure of Sm2O3 and Co3O4, which facilitates the diffusion of ions and prevents structural collapse during charging and discharging. A substantial number of active sites are generated during redox reactions by the unique surface morphology of the Sm2O3/Co3O4/rGO/NF composite (SCGN). The maximum specific capacity the SCGN material achieves is 3448 F g-1 for 1 A g-1 in a 6 mol L-1 KOH solution. Benefiting from its morphological structure, the prepared composite (SCGN) exhibits a high cyclability of 93.2% over 3000 charge-discharge cycles at 10 A g-1 and a coulombic efficiency of 97.4%. Additionally, the assembled SCGN//SCGN symmetric supercapacitors deliver a high energy density of 64 W h kg-1 with a power density of 300 W kg-1, which increases to an outstanding power density of 12 000 W kg-1 at 28.7 W h kg-1 and long cycle stability (80.9% capacitance retention after 30 000 cycles). These results suggest that the manufactured SCGN electrodes could be viable active electrode materials for electrochemical supercapacitors.
