Interface Engineering of Nickel Selenide and Graphene Nanocomposite for Hybrid Supercapacitor

Nickel selenide is an emerging electrode material for high-performance hybrid supercapacitors; however, poor electrical conductivity and sluggish ion kinetics limit its application. Herein, a unique architecture by decorating NiSe nanoparticles on reduced graphene oxides (rGO) is developed. The synergistic effect of NiSe and rGO facilitated by the optimized addition of rGO results in significant improvement in the electrochemical performance. The physicochemical characterizations suggest that the enhancement can be attributed to increased interfacial interaction and access to the electrochemically active sites. The NiSe/rGO hybrid delivers a specific capacity of 351 mAh g(-1) at 1 A g(-1), which is significantly higher than that for bare NiSe. Later, the hybrid supercapacitor based on NiSe/rGO hybrid as positive and activated carbon as negative electrode delivers a maximum energy density of 49.6 Wh kg(-1) at a power density of 748.37 W kg(-1). In addition, the device shows good cyclic stability of 83.3% over 5000 cycles. Thus, an innovative approach to the development of high-performance hybrid supercapacitors is offered.