Tiny Ni0.85Se nanosheets modified by amorphous carbon and rGO with enhanced electrochemical performance toward hybrid supercapacitors

Abstract

• Ni 0.85 Se@C/rGO composite was synthesized via programmed temperature controlling. • The dual carbon modified structure ensures the electric connection. • The combination of dual carbon provides confinement to inhibit disintegration. • The device exhibits high specific energy, specific power and long-term cycling stability. Considering that electrode materials for supercapacitors suffer poor cycling stability and low electrons transfer at high current density, combination with carbonaceous materialhas has been devoted to strengthen the conductivity and improve the specific power and specific energy. Herein, the Ni 0.85 Se@C/rGO composite with tiny Ni 0.85 Se nanosheeets anchoring on rGO and coated by amorphous carbon has been successfully synthesized via programmed temperature controlling. As combined with dual modified carbon, which not only can ensure the electric connection of all the tiny Ni 0.85 Se nanosheets, but also provide confinement to inhibit disintegration, the Ni 0.85 Se@C/rGO//AC supercapacitor device shows a thrilling specific energy of 45.6 Wh kg −1 and 31.4 Wh kg −1 at specific power of 463.5 W kg −1 and 9.4 kW kg −1 , respectively. With the dual carbon modification of amorphous carbon and rGO, Ni 0.85 Se@C/rGO//AC hybrid supercapacitor device shows satisfactory cycling stability and high specific energy and specific power