Role of graphene in NiSe2/graphene composites - Synthesis and testing for electrochemical supercapacitors

Nickel selenide and its nanocomposites (Nickel selenide-graphene; NiSe2/G, nitrogen and boron doped graphene designated as NiSe2/NG & NiSe2/BG respectively) were prepared using hydrothermal route and these materials were further exploited for its activity towards energy storage. The prepared materials were investigated with various analytical and morphological analysis like X-ray diffractometer and FESEM analysis. Further the prepared materials were probed for its electrochemical characteristics with various tools like voltammetric and controlled potentiostatic test to calculate the capacitance, energy and power density of the fabricated electrode. The electrochemical behavior of nickel selenide graphene nanocomposites were tested in KOH electrolyte. It was found that NiSe2/NG showed a high specific capacitance of 99.03 Fg−1 with 0.55 W kg−1 and 51.43 Wh kg−1 power and energy density respectively. A detailed study has been carried out to know the role of graphene and doped graphene towards capacitance. Hence, results proved that doping of graphene showed a synergistic effect thus proving a good electrode for storage applications. [Display omitted] •NiSe2 nanocomposites with undoped and doped graphene (B & N) were synthesized by hydrothermal method.•The composites (NiSe2/NG) show a maximum capacitance of 99.03 F/g vs. Ag/AgCl.•NiSe2 and doped graphene show a synergic effect thus, a suitable material for supercapacitor applications.