Direct growth of NiCo2O4 nanosheet arrays on 3D-Ni-modified CFs for enhanced electrochemical storage in flexible supercapacitors

Abstract

The rapid development of wearable and portable smart equipment has led to a research boom in flexible energy storage devices. Herein, NiCo2O4 nanosheet arrays have been successfully grown on carbon fibers (CFs), which was firstly modified by the three-dimensional Ni (3D-Ni) to repair the cracks and grooves in the surface of CF. The obtained CFs@3D-Ni/NiCo2O4 electrode possesses a high specific capacity of 736 F/g at 1 A/g current density in the three-electrode system. More importantly, the composite showed excellent electrochemistry stability after temperature plummets. The all-solid-state asymmetric supercapacitor device (ASC) assembled by CFs@3D-Ni/NiCo2O4 delivers a wonderful specific capacity of 176 F/g, a high energy density 55 W h/Kg at 750 W/Kg, excellent cycling stability (about 97.84% after 2000 cycles), and high flexibility (almost no influence in electrical performance at various bending angles). This work has provided a promising method to prepare high performance of the flexible and lightweight energy storage equipment.