One-step solvothermal in situ synthesis of NiMOF nanosheets for high-performance supercapacitor applications†

Abstract

In this study, NiMOF nanosheets were successfully synthesised on nickel foam using a simple solvothermal method. The nanosheets self-assembled on the nickel foam to form a uniform open pore structure, which allowed the electrode material to expose more active sites. This method avoided the use of insulating binders and additional electrode treatments, simplified the preparation process of NiMOFs, and improved the conductivity and mechanical stability of the electrode materials. The prepared NMF-1 electrode exhibited a specific capacitance of 1238 F g⁻¹ at 1 A g⁻¹ and maintained a high specific capacitance of 840 F g⁻¹ at 5 A g⁻¹. The assembled asymmetric supercapacitor (ASC) exhibited a specific capacitance of 126.56 F g⁻¹ at 1 A g⁻¹, specific capacitance retention rate of 81.2% at 5 A g⁻¹, and an energy density of 45 W h kg⁻¹ at a power density of 800 W kg⁻¹. These results indicate that mixed solvent-modulated in situ growth of NiMOF nanosheets on nickel foam has great potential in supercapacitor applications.