Facile synthesis of a two-dimensional layered Ni-MOF electrode material for high performance supercapacitors

Abstract

Recently, various metal–organic framework (MOF)-based supercapacitors (SCs) have received much attention due to their porosity and well-defined structures. Yet poor conductivity and low capacitance in most MOF-based devices limit their wide application. As an electrode material, 2D MOFs exhibit a rapid electron transfer rate and high specific surface area due to their unique structures. In this work, a 2D layered Ni-MOF is synthesized through a simple solvothermal method and serves as an electrode material for SCs. Electrochemical studies show that the Ni-MOF exhibits low charge transfer resistance, excellent specific capacitance of 1668.7 F g⁻¹ at 2 A g⁻¹ and capacitance retention of 90.3% after 5000 cycles at 5 A g⁻¹. Moreover, Ni-MOF//AC asymmetric SCs are assembled. The device exhibits high specific capacitance of 161 F g⁻¹ at 0.2 A g⁻¹ and the energy density reached 57.29 W h kg⁻¹ at a power density of 160 W kg⁻¹. The high electrochemical performance can be ascribed to the inherent porosity of MOFs and the 2D layered structure.