Fabrication of NiCo2O4 and carbon nanotube nanocomposite films as a high-performance flexible electrode of supercapacitors

Herein, we demonstrated facile fabrication of NiCo2O4 nanoparticles on a CNT film by a chemical deposition method, followed by thermal annealing treatment processing. The synthesized NiCo2O4/CNT nanocomposite films were still highly flexible, porous, and conductive. Scanning electrical microscopy (SEM) and transmission electronic microscopy (TEM) observation showed that the web-like structure of the films is still preserved and each carbon nanotube in the film was uniformly wrapped by ball-like nanoparticles (ca. 5 nm). X-Ray Diffraction (XRD) measurement confirmed that spinel NiCo2O4 was successfully synthesized during the experiment. The contents of NiCo2O4 in the composite films could be controlled by tuning the deposition times. The flexible, porous and conductive nanocomposite films could be employed as high-performance flexible energy saving installments. The three-pole measurements illustrated that the composite films possessed a capacitance of 828 F g(-1) at 1 A g(-1), and retained over 99% of their capacitance after 3000 cycles of charge/discharge at 5 A g(-1), showing high-performance electrochemical properties. Finally, an asymmetric supercapacitor installment was assembled by using the composite film as the positive electrode and commercially available activated carbon (AC) as the negative electrode. The measurement gave an energy density of 28.58 W h kg(-1) at a power density of 0.7 kW kg(-1).