Waste stainless steel mesh anodized under hydrothermal environment for flexible negative electrode of supercapacitor

Fe2O3/NiO nanocomposites were fabricated by anodising waste stainless-steel mesh under hydrothermal environment with high specific surface area and were then used as a flexible negative electrode. The as-prepared composites were studied by powder X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy and N2 adsorption–desorption measurements. Electrochemical evaluations in 1 mol l−1 KOH solution confirmed that the anodised stainless-steel mesh as a negative electrode exhibited a maximum areal capacitance of 1.22 F cm−2 and remarkable cycling stability with 93.3% initial-capacitance retention after 10,000 charging and discharging cycles, indicating promising flexible-supercapacitor applications.