Carambola-like Ni@Ni_1.5Co_1.5S₂ for Use in High-Performance Supercapacitor Devices Design

Studies on supercapacitor devices constitute one of the most meaningful research topics in hastening the industrialization of electrode materials. Herein, uniform nanosheet-based carambola-like Ni@Ni_1.5Co_1.5S₂ was successfully synthesized and assembled into an asymmetric supercapacitor device with a high specific capacitance of 109 F g^–1 at a current density of 1 A g^–1. The large mass loading of this device, at ∼20 mg cm^–2, is compatible with the industry standard and considerably higher than those obtained in previous reports. The Ni@Ni_1.5Co_1.5S₂-based supercapacitor device exhibited excellent cycling stability with virtually no decrease in capacitance after 2000 cycles, and achieved a high energy density of 65.7 W h kg^–1 at a power density of 22.2 W kg^–1 and a high power density of 3 kW kg^–1 at energy density of 6.2 W h kg^–1. These outstanding characteristics of Ni@Ni_1.5Co_1.5S₂ as an electrode material for supercapacitor devices verify its promising applicability in the energy storage field.