Cu-Ag-C@Ni3S4 with core shell structure and rose derived carbon electrode materials: An environmentally friendly supercapacitor with high energy and power density

Transition metal sulfides (TMS) are extraordinary electrode materials for supercapacitors inasmuch as their champion stability and conductivity when paired with carbon-based materials. In this study, we report the technology of creating core-shell Cu-Ag-C@Ni3S4 (CAC-NS) nanocomposites by carbon coating and solvothermal processing of 2D Cu-Ag NWs (CA NWs). The conductive carbon covering, huge specific surface area of the nanowires, and cross-connecting Ni3S4 (P-NS) nanoparticles give the CAC-NS electrode outstanding electrochemical conductivity and stable cycling behavior. Thus, high cycle performance (83 % capacity retention after 5000 cycles at 20 A g−1) and specific capacitance (2507.2 F g−1 at 1 A g−1) are attributes of the CAC-NS. In contrast, the main reason why the specific capacitance of CAC-NS is higher than that of Cu-Ag-C@Ni3S4 (CA-NS) (1937.2 F g−1 at 1 A g−1) is due to the conductivity of the glucose carbon layer. A device with rose-derived carbon (RDC) and CAC-NS as the anode and cathode electrodes performs well at high current density (capacitance retention rate of 90.4 % after 10000 cycles at 20 A g−1) and exhibits a large specific capacitance (366.2 F g−1 at 1 A g−1). The device (CAC-NS//RDC) can display both a high power density (4494.3 W kg−1 at 24.4 Wh kg−1) and a satisfactory energy density (224.8 W kg−1 at 69.8 Wh kg−1), suggesting that it has a wide variety of practical applications. The broad range of applications for CAC-NS nanocomposites in extremely effective supercapacitors is further illustrated by these encouraging findings. [Display omitted] •A core-shell heterostructure Cu-Ag-C@Ni3S4 nanocomposite is designed.•Rose-derived carbon is prepared by salt activation and high-temperature calcination.•The device Cu-Ag-C@Ni3S4//RDC has exceptional cycle performance and high energy density.•The device exhibits 366.2 F g−1 specific capacitance at 1 A g−1.•After 10,000 cycles, the capacity retention rate of the device reaches 90.4 %.