Facile Electrochemical Deposition of Porous NiCo2S4 on FeCo2O4 Array as a Positive Material for Battery-Supercapacitor Hybrid Device

Electrode design is of significant importance in the construction of enhanced electrochemical performance, and nanoarray is an attractive architecture for energy storage devices with a large specific surface area. Herein, we report the development of binary FeCo 2 O 4 @NiCo 2 S 4 array tubes on Ni foam (Ni@FeCo 2 O 4 @NiCo 2 S 4 ) as an efficient non-noble-metal electrode material for battery-supercapacitor hybrid device in alkaline electrolytes. Meanwhile, the unique 3D structure provides a desirable large electroactive area and rapid electron conductivity, resulting in remarkable electrochemical behavior in terms of high specific capacity (5.99 W cm −2 with a 260 mWh cm −2 of energy density for Ni@FeCo 2 O 4 @NiCo 2 S 4 ). The long-term cycling stability of 76.9% capacity retention after 5000 cycles at 50 mA cm −2 for Ni@FeCo 2 O 4 @NiCo 2 S 4 could be obtained. These results demonstrate that the fabricated high-performance electrode materials can be a promising candidate for battery-supercapacitor hybrid devices.