Battery-Type Electrodes for Hybrid Supercapacitors Made from Heterostructured NiSe ₂ /MoSe ₂ /NF Hollow Microspheres

The hollow structure of transition metal selenides can significantly boost the energy storage capability thanks to their attractive two-dimensional nanostructure and large exposed surface area. In this study, the heterostructured NiSe 2 /MoSe 2 /NF microspheres with cavity structure were obtained via a hydrothermal selenization process. The duration of the selenization process significantly affected both the electrode materials’ morphology and capacity properties. Electrochemical testing conveyed that the NiMoSe-6 microspheres (NiSe 2 /MoSe 2 ) treated with selenium for 6 h were the best, measuring 275 mAh g –1 at 1 A g –1 . In addition, the NiSe 2 /MoSe 2 //AC device presented an impressive specific energy density of 53.7 Wh kg –1 at a density of 749.9 W kg –1 . Furthermore, the two homemade pieces of the NiSe 2 /MoSe 2 //AC device in series (2 × 2 cm 2 ) successfully powered multicolored LED lights or an electronic timer. The strategy of enhancing performance by regulating selenization time serves as a valuable guideline for designing advanced transition metal selenides.