Rational design of NiSe2@rGO nanocomposites for advanced hybrid supercapacitors

Hybrid supercapacitors represent a promising candidate for grid-scale energy storage devices because of their excellent high-power density, inherent safety and low cost. Here we report a novel NiSe2@rGO nanocomposite (reduced graphene oxide decorated NiSe2 nanoparticles), which shows high specific capacity of 467 C g−1 at 1 A g−1 and superior rate performance (∼72.8% of the capacity retention at 20 A g−1). Moreover, a hybrid supercapacitor (HSC) assembled from the NiSe2@rGO positive electrode and rGO negative electrode delivers high energy density (34.3 Wh kg−1) and splendid cycling lifespan (∼93% of the capacity retention over 6500 cycles). This study provides a novel insight on high-performance hybrid supercapacitors.