Construction of complex copper-cobalt selenide hollow structures as an attractive battery-type electrode material for hybrid supercapacitors

The application of battery-like electrode materials with complex hollow structures, huge surface areas, and good redox properties is an appealing approach towards the boosting performance of hybrid supercapacitors. This work proposes a facile strategy for the fabrication of copper-cobalt selenide hollow spheres (CCSe-HSs) as a new battery-type electrode for hybrid supercapacitors. Benefiting from the considerable electrical conductivity and rationally porous structures, this electrode exhibits a higher capacitance/capacity of 1775.4F g−1/295.9 mAh g−1 compared with copper-cobalt sulfide hollow spheres (CCS-HSs) and copper-cobalt oxide hollow spheres (CCO-HSs). Besides, an advanced device (CCSe-HSs//AC) constructs by combining copper-cobalt selenide hollow spheres (positive electrode) and activated carbon (AC, negative electrode). Our device reflects reasonable energy and power densities (53.86 W h kg−1 at 800 W kg−1, respectively), and desirable cyclability. Our current study provides a rationale and efficient design strategy to engineer new bimetallic selenides with complex hollow structures for different applications.