Synthesis of porous Ag <sub>2</sub> S−NiCo <sub>2</sub> S <sub>4</sub> hollow architecture as effective electrode material with high capacitive performances
Diab Khalafallah, Chong Ouyang, Mingjia Zhi, Zhanglian Hong
Abstract
Abstract Fabrication of highly reactive and cost-effective electrode materials is a key to efficient functioning of green energy technologies. Decorating redox-active metal sulfides with conductive dopants is one of the most effective approaches to enhance electric conductivity and consequently boost capacitive properties. Herein, hierarchically hollow Ag 2 S−NiCo 2 S 4 architectures are designed with an enhanced conductivity by a simple solvothermal approach. With the favorable porous characteristics and composition, the optimized Ag 2 S−NiCo 2 S 4 -5 electrode exhibits higher specific capacitance (276.5 mAh g −1 at a current density of 1 A g −1 ), a good rate performance (56.3% capacity retention at 50 A g −1 ), and an improved cycling stability (92.4% retention after 2000 cycles). This finding originates from the enhanced charge transportation ability within the hierarchical structure, abundant electroactive sites, and low contact resistance. In addition, a battery supercapacitor device constructed with the Ag 2 S−NiCo 2 S 4 -5 as a positive electrode displays a maximum energy density of 63.3Wh kg −1 at an energy density of 821.8 W kg −1 with an excellent cycling stability (89.4% capacity retention after 10 000 cycles). Therefore, the present work puts forward new possibility to develop composite electrodes for energy storage battery-supercapacitor.