Ultrafast metal corrosion engineering facilitates the construction of CoSx derived from MOFs as enhanced supercapacitor electrodes

Abstract

The rational design and fabrication of self-supporting composites based on metal–organic frameworks (MOFs) are essential for employing MOFs as precursors. However, the weak contact between the current collector and MOF precursors limits the full utilization of their performance. In this study, we employed a rapid self-induced intermetallic corrosion effect to modify a nickel foam current collector. This modification not only provided nucleation sites for MOF precursors but also contributed to additional capacitance. Furthermore, the energy-storage capability of the composites was enhanced by sulfurizing the modified current collector in synergy with MOF precursors. In addition, the entire preparation process required only 1 hour of thermal energy consumption. The resulting CoS_x@NiFe-S@NF composite possessed an ultrahigh specific capacitance of 4.1 F cm⁻² and could retain 54.4% of its initial capacity even at 20 mA cm⁻², demonstrating exceptional rate performance. Moreover, the assembled asymmetric supercapacitor achieved an outstanding energy density of 29 W h kg⁻¹ at a power density of 800 W kg⁻¹ and retained 80.7% of its initial capacity after 5000 cycles at 10 A g⁻¹. This strategy of current collector modification and synchronous sulfurization provides a new design concept for enhancing the electrochemical performance of MOF-derived materials.