One-dimensional flexible supercapacitors based on ZnCo2O4/MnCoP composite electrodes with enhanced electrochemical performance

Abstract

The increasing demand for flexible electronics in modern applications intensifies the need for adaptable, high-performance energy storage systems. Among them, one-dimensional flexible supercapacitors gain considerable attention for their structural integrity and mechanical flexibility. In this work, a ZnCo₂O₄@MnCoP (ZCO/MCP) composite is synthesized on nickel wire (NW) via a two-step hydrothermal method, while helical carbon fibers are grown on copper wire (CW) using chemical vapor deposition. The hierarchical structure of ZCO nanosheets decorated with MCP nanoparticles effectively enlarges the electroactive surface area and provides abundant redox sites. The synergistic interaction between the metal oxide and phosphide phases further enhances electrical conductivity and charge storage capability. An asymmetric flexible supercapacitor is assembled using NW@ZCO@MCP and CW@CF as the positive and negative electrodes, respectively. The device achieves volumetric and areal capacitances of 3.515 F cm⁻³ and 0.0185 F cm⁻² at 0.2 A cm⁻³, with an energy density of 2.5 mWh cm⁻³ and a power density of 320.011 mW cm⁻³. It also exhibits excellent cycling stability, retaining 85.54% of its initial capacitance after 7500 charge-discharge cycles. These results demonstrate the strong potential of the NW@ZCO@MCP//CW@CF architecture for flexible and miniaturized energy storage applications.