In-situ synthesis of three-dimensionally flower-like Ni3V2O8@carbon nanotubes composite through self-assembling for high performance asymmetric supercapacitors

To develop a high-performance positive electrode for asymmetric supercapacitor (ASC), a novel Ni3V2O8@carbon nanotubes (CNTs) composite with three-dimensionally (3D) flower-like structure is designed and prepared through an in-situ hydrothermal method. The particularly open architecture self-assembled by interlacement of Ni3V2O8 nano-petals with a high surface area provides interconnected ion diffusion channels and highly exposed active centers for ion absorption. The electrical conductivity and charge transport are greatly improved by anchoring CNTs on Ni3V2O8. The synergistic effect between Ni3V2O8 and CNTs gives rise to an improved electrochemical performance with high specific capacitance (1054 F g(-1) at 1 A g(-1)), good rate capability and excellent cycling stability (89% capacitance retention after 10,000 cycles). An ASC equipped with a Ni3V2O8@CNTs positive electrode and an activated rice husk carbon (ARHC) negative electrode achieves a remarkable energy density of 45.5 Wh kg(-1) at 795 W kg(-1) and outstanding cycling stability after 10,000 cycles in a wide operating voltage window of 1.6 V. The impressive performance of the Ni3V2O8@CNTs composite makes it a promising candidate for commercial application.