ZIFs derived multiphase CoSe2 nanoboxes induced and fixed on CoAl-LDH nanoflowers for high-performance hybrid supercapacitor

Reasonable structures are beneficial to improve the electronic transfer efficiency of the electrode. A novel two/three-dimensional structure with multiphase CoSe 2 (M-CoSe 2 ) nanoboxes fixed on CoAl-LDH nanoflowers on carbon paper (CP) is reasonably designed. The formation mechanism of M-CoSe 2 is systematically studied through the gradient change of the selenization conditions. Benefitting from the hollow structure of the ZIFs derivatives (carbon-nitrogen frameworks, CNFs), numerous charge transfer channels are provided. Furthermore, M-CoSe 2 with enhanced conductivity can furnish abundant active sites and a synergistic effect. The specific capacity of the optimal anode M-CoSe 2 /CNFs/CoAl-LDO/CP can reach 343.6 mAh g −1 at 1 A g −1 , which is equivalent to twice that of the monomer material. The hybrid-supercapacitor (M-CoSe 2 /CNFs/CoAl-LDO/CP//activated carbon) can provide a high energy density of 50.8 Wh kg −1 at 800 W kg −1 , and high stability (capacity loss rate of 3.2%, 10,000 cycles). Besides, LEDs can be lit by HSCs, demonstrating their application potential.