One-step salt-assisted solution combustion synthesis of Ni-based composites for use as supercapacitor electrodes

Low cost mass production of Ni-based composites on an industrial scale with high electrochemical performance is of practical interest for supercapacitors. In this report, various Ni-based composites containing Ni2(CO3)(OH)2, Ni3(NO3)2(OH)4, NiC2O4 or NiO have been successfully synthesized via a one-step salt-assisted solution combustion synthesis at a temperature of 215 °C. The morphology and chemical composition of the as-obtained products can be controlled by monitoring the reaction parameters inclusive of the initial concentration of salt solution, and salt species. NC-1.0 composite obtained by salt-assisted solution combustion synthesis delivers higher specific capacitance (1420 F g−1 at 1 A g−1), and better cycling performance (60.0% after 2000 cycles) than those of NC-0.0 (1260 F g−1 at 1 A g−1, 53.6% after 2000 cycles) achieved by conventional solution combustion synthesis. Hybrid supercapacitor with NC-1.0 composite as positive electrode and active carbon as negative electrode delivers high energy density (32.5 Wh kg−1 at a power density of 310.2 W kg−1). The performance of the obtained Ni-based composites as supercapacitor electrodes demonstrates their potential for upcoming electronic devices.