Mesoporous nickel cobalt manganese sulfide yolk-shell hollow spheres for high-performance electrochemical energy storage

Electrode materials with complex hollow architectures, large specific surface area, and porosity as well as more inner cavities are widely employed for high-performance supercapacitors. In the current work, we report a simple self-templating strategy to prepare a complex nickel cobalt manganese sulfide yolk-shell hollow sphere. Uniform nickel cobalt manganese glycerate solid spheres are first prepared as the template and subsequently transformed into nickel cobalt manganese sulfide yolk-shell hollow spheres by a sulfidation process. When utilized as electrode materials for electrochemical supercapacitors, the resultant nickel cobalt manganese sulfide yolk-shell hollow spheres exhibited a large specific capacitance of 1360 F g(-1) at 1.0 A g(-1) and superior rate capability. Furthermore, an asymmetric supercapacitor device was assembled using the nickel cobalt manganese sulfide yolk-shell hollow spheres and activated carbon. The device showed a high energy density of 49.8 W h kg(-1) at a power density of 1700 W kg(-1) and long-term cycling life (only 1.8% loss after 6000 cycles), suggesting their potential application in high-performance electrochemical energy storage.