Hierarchical copper selenide nanoneedles grown on copper foil as a binder free electrode for supercapacitors

•Copper selenide were grown on Cu foil via hydrothermal route.•FE-SEM analysis showed the formation of CuSe2 nanoneedles.•CuSe2/Cu binder-free electrode delivered a high specific capacitance of 1037 F/g.•The CuSe2/Cu electrode possesses a high energy density of about 51.85 Wh/kg.

In this communication, we demonstrated the use of CuSe2 nanoneedles grown on copper foil as a binder-free electrode for supercapacitors. Studies using X-ray diffraction, laser Raman spectroscopy and field emission scanning electron microscopy confirmed the formation of crystalline CuSe2 nanoneedles on the surface of copper foil. Cyclic voltammetry and electrochemical impedance spectroscopy revealed the pseudocapacitive nature of the CuSe2/Cu electrode. The galvanostatic charge–discharge analysis showed that the CuSe2/Cu binder-free electrode delivered a high specific capacitance of about 1037.5 F/g at a constant current density of 0.25 mA/cm2.