Construction of hierarchical layered hydroxide grown in situ on carbon tubes derived from a metal–organic framework for asymmetric supercapacitors

Abstract

Electrode materials are very important for the performance of supercapacitors (SCs). Therefore, preparation of hybrid electrode materials is an effective way to develop high-performance SCs. We firstly design and prepare metal organic framework (MOF) derived carbon nanotubes as the core skeleton to support the shell of a nickel gallium layered hydroxide nanosheet (NiGa-LDH). MOF derived carbon nanomaterials have high conductivity and a large specific surface area, which can promote electron transfer and improve the agglomeration of LDH. The deposited LDH can provide high specific capacitance and the layered structure can further enhance the reaction site. The NiGa-LDH@CNT-500@CC has an excellent specific capacitance of 2580 F g⁻¹ at 1 A g⁻¹ and a high capacitance retention rate of 83.3% at 5 A g⁻¹ due to the synergistic effect of two materials. The assembled NiGa-LDH@CNT-500@CC//carbon NS asymmetric supercapacitor (ASC) has an operating voltage of 1.6 V and a high energy density of 52 W h kg⁻¹ at a power density of 952 W kg⁻¹. Therefore, the core–shell structure composed of LDH and carbon nanomaterials provides an effective way for the design of high-performance electrodes.