Facile synthesis of three-dimensional nanostructured Ni(HCO3)2/(Cu0.2Ni0.8)O as high-performance pseudo-capacitance electrode

The novel three-dimensional (3D) Ni(HCO3)2/(Cu0.2Ni0.8)O nanomaterials with granular and needle-like structures are synthesized as electrode materials for supercapacitors by a facile one-step solvothermal method. In this work, nickel-copper bimetallic oxide obtained by introducing copper ions is committed to accelerating charge transport and improving the electronic conductivity of the composites to thereby obtain high-performance electrode materials. Herein, further optimization of material properties are obtained by revealing the optimum molar ratio between nickel and copper. The maximum specific capacitance of the prepared electrode materials are 2000 F g−1 at current density of 1 A g−1, which is evidently higher than that of the sample prepared without copper incorporation. An asymmetric supercapacitor device is fabricated using NC-d as the positive electrode and activated carbon as the negative electrode. The NC-d//AC device has high energy density and power density (52.9 Wh kg−1 at 160 W kg−1, and 22.2 Wh kg−1 at 8000 W kg−1), indicating the great potential of NC-d to practical application as supercapacitor electrode materials.