Slow-Scan anodization of copper in alkaline Solution: Synthesis, performance Evolution, and theoretical analysis of Cu(OH)2 nanowires for High-Performance supercapacitors

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2025-02, Vol.312, p.117841, Article 117841
• Main Authors: Daamouche, Mosbah, Guitoume, Djamal Eddine, Lahmar, Halla, Bouheroum, Sofiane, Boudissa, Mokhtar, Farh, Hichem
• Format: Article
• Language: English
• Subjects: Binder free electrode; Cu(OH)2; CuO; Cyclic Stability; Potentiodynamic anodization; Supercapacitor
• ISSN: 0921-5107
• DOI: 10.1016/j.mseb.2024.117841

[Display omitted] •Fabrication of binder-free Cu/Cu(OH)2 nanowire bundles electrodes via simple anodization.•Anodization at 0.1 mV/s yielded the highest capacitance of 22.5 mF/cm2 at 1 mA/cm2.•The electrode retained 120% of capacitance after 10,000 charge–discharge cycles.•Phase transformation from Cu(OH)2 nanowire bundles to CuO nanosheets observed after cycling stability tests.•Strong correlation between supercapacitor performance, electrode surface morphology and diffusion coefficients (D). In this work, a binder-free Cu/Cu(OH)2 NwBs electrode was fabricated using a simple potentiodynamic anodization method. The effect of anodization scan rates of 3, 0.5, and 0.1 mV/s on the structural, morphological, and supercapacitive properties was thoroughly investigated. An areal capacitance of 22.5 mF/cm2 at 1 mA/cm2 was achieved at scan rate of anodization 0.1 mV/s. The Cu/Cu(OH)2 electrode demonstrates excellent retention cyclic stability of 120 % after 10,000 cycles. Post-cycling analysis revealed a phase transformation from Cu(OH)2 to CuO, accompanied by significant morphological changes. A theoretical model based on Fick’s law was employed, which aligned well with the experimental data. The diffusion coefficient values were calculated from charge/discharge data, and the results indicated that higher diffusion coefficients corresponded to higher specific capacitance, demonstrating improved supercapacitor performance.