Constructing flower-like NiCo-MOFs with different ratio of DMF-methanol mixed solvent as electrode materials for asymmetric supercapacitor device

DMF-CH 3 OH solvothermal mixed solvent. • High capacitance value of 2495 F/g at 1 A/g. • Capacitance value 175 F/g at 1 A/g of the ASC device. • Energy density of 54.3 Wh·kg −1 at power density of 744.5 W kg −1 of ASC device. Metal-organic frameworks (MOFs) have attracted great research attention as electrode materials for supercapacitors due to their unique advantages. In this work, a series of NiCo-MOFs were synthesized through a simple solvothermal method. This work mainly adopts DMF and methanol as the mixed solvent in the solvothermal process. By adjusting the ratio of DMF to methanol (1:1-4:1), NiCo-MOFs with similar morphologies but different electrochemical properties were obtained. Among the four solvent ratios, NiCo 21 -MOF (DMF:CH 3 OH = 2:1) exhibits excellent electrochemical performance with a specific capacitance of 2495 F/g at 1 A/g. The NiCo 21 -MOF//AC asymmetric supercapacitor (ASC) device exhibits a specific capacitance of 175 F/g at 1 A/g, and the energy density and power density are 54 Wh kg −1 and 744 W kg −1 , respectively. After 5000 cycles, the ASC device still retains 85% of its initial capacitance, with good stability. In conclusion, this work achieves excellent electrochemical performance of NiCo-MOFs by adjusting the solvent ratio, providing a new strategy for synthesizing NiCo-MOFs with excellent electrochemical properties. Download: Download high-res image (313KB) Download: Download full-size image