▎ 摘　　要

Homogeneous ZnCo2O4 nanoflowers have been synthesized on a 3D layered structure of carbon nanotubes/nitrogen-doped graphene (NGN/CNTs) film by a hydrothermal process and subsequent calcination method. The ZnCo2O4 nanoflowers have an average diameter of 4 mu m, and are composed of petals less than 100 nanometers. The as-synthesized ZnCo2O4/NGN/CNT film can be directly used as a flexible electrode with a high specific capacitance of 1802 F g(-1) at 1 A g(-1) and excellent cycling stability (almost 0% fade after 4000 sustaining charge/discharge at 10 A g(-1)). These results suggest that the obtained electrode has a promising application prospect in flexible energy conversion/storage devices. In addition, a binder-free asymmetric supercapacitor has been synthesized with the ZnCo2O4/NGN/CNT film as the positive electrode and the NGN/CNT film as the negative electrode. This demonstrates superior energy density (approximate to 37.19 W h kg(-1) at 750 W kg(-1)) and power density (approximate to 14.992 kW kg(-1) at 14.16 W h kg(-1)).