Synthesis of urchin-like NiCo 2 S 4 electrode materials based on a two-step hydrothermal method for high-capacitance supercapacitors

The specific capacity of urchin-like NiCo 2 S 2 is 1352 F g −1 at a current density of 1 A g −1 . The NiCo 2 S 4 //AC ASC device provides high energy density at a power density of 2025 W kg −1 . The capacitance retention of NCS-1.5//AC is 81.98% after 10 000 cycles of charging and discharging.