Fabrication of novel coral reef-like nanostructured ZnFeNiCo2S4 on Ni foam as an electrode material for battery-type supercapacitors

• Novel quaternary sulfides (ZnFeNiCo 2 S 4 /NF) were prepared by the facile hydrothermal method. • ZnFeNiCo 2 S 4 /NF nano-coral reefs electrode exhibited a high specific capacity of 1778 C g −1 . • ZnFeNiCo 2 S 4 /NF//ZnFeNiCo 2 S 4 /NF battery-type symmetric supercapacitor displayed superior electrochemical performances. • The battery-type symmetric device exhibited high specific energy and good cycling stability. Battery-type electrode materials have recently been explored as a novel class of high-capacity cathode materials in the development of hybrid supercapacitors. In the study, a novel nano coral-reef ZnFeNiCo 2 S 4 quaternary sulfide was synthesized in two easy hydrothermal stages on a Ni Foam (NF) substrate for advanced battery-type supercapacitors. In three or two electrode systems, the ZnFeNiCo 2 S 4 /NF was applied as a potential electrode for battery-type supercapacitors. According to the result, the ZnFeNiCo2S4/NF electrode was successfully synthesized as a binder-free electrode on the Ni foam. The electrochemical investigation of the ZnFeNiCo 2 S 4 /NF showed a high specific capacity of 1778 C g −1 at a current density of 3 A g −1 with excellent cycling stability of 86.1% capacity retention and 100% coulombic efficiency at 6 M KOH as the electrolyte. The battery-type symmetric supercapacitor measured a specific capacitance of 162.3 C g −1 at a current density of 2 A g −1 with a specific energy of 33.8 Wh kg −1 at a specific power of 2519.25 W kg −1 . On the contrary, asymmetric supercapacitors exhibit excellent cycling stability, approximately 94.7% capacity retention after 6000 cycles, and a 100% coulombic efficiency. Due to their excellent electrochemical characteristics, the high-performance ZnFeNiCo 2 S 4 nano coral reef-like structure is a promising electrode material for high-performance supercapacitors.