This study presents the hydrothermal synthesis and characterization of cobalt-doped strontium titanate (Co-doped SrTiO3) nanostructures directly grown on nickel foam (NiF) as high-performance binder-free electrode materials for supercapacitor applications. The incorporation of cobalt into the SrTiO3 lattice aims to improve the electrical conductivity of the material and enhance its electrochemical behavior, thereby enabling more efficient charge storage and energy transfer. A facile hydrothermal method was employed for the direct growth of Co-doped SrTiO3 on Ni foam, which acted as both a structural support and current collector, enabling a binder-free configuration that improved electrical connectivity and active material utilization. The successful formation of the Co-doped SrTiO3 phase on the Ni foam was confirmed by X-ray diffraction (XRD) analysis, which provided insights into its crystalline structure and phase purity. Further chemical bonding and functional group analyses were performed using Fourier-transform infrared spectroscopy (FTIR), which confirmed the presence of characteristic metal–oxygen stretching vibrations corresponding to the Co–O and Ti–O bonds, supporting the successful doping and incorporation of cobalt into the SrTiO3 matrix. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses were used to investigate the surface morphology and nanostructure, which revealed a well-defined hierarchical architecture. The electrochemical performance was evaluated in a three-electrode setup using a 1 M Na2SO4 aqueous electrolyte. Cyclic voltammetry (CV) revealed prominent redox peaks, confirming the pseudocapacitive nature of the electrode. Galvanostatic charge–discharge (GCD) tests demonstrated a high specific capacitance, while electrochemical impedance spectroscopy (EIS) indicated low internal resistance and good charge-transfer characteristics. Among the prepared samples, NC3 exhibited the best electrochemical performance because it had an optimal amount of cobalt and a well-connected porous structure. NC3 delivered a high specific capacitance of 403.17 F g⁻1 at a scan rate of 5 mVs⁻1 and maintained 85.44% capacitance retention after 10,000 cycles, indicating excellent cycling stability. Furthermore, the assembled device achieved a maximum energy density of 15.24 Wh kg−1. These findings highlight that the binder-free, nanostructured Co-doped SrTiO3 directly grown on Ni foam is promising for use in next-generation high-performance supercapacitors, owing to its enhanced electrical properties and robust structural integrity.

Facile hydrothermal growth of co-doped SrTiO₃ on 3D nickel foam for advanced binder-free supercapacitor electrodes

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发表日期：

2025年7月23日

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Vaibhav R. Shrikhande,
Santosh J. Uke,
Satish P. Mardikar,
Gajanan N. Chaudhari,
Anjali B. Bodade

摘要

This study presents the hydrothermal synthesis and characterization of cobalt-doped strontium titanate (Co-doped SrTiO₃) nanostructures directly grown on nickel foam (NiF) as high-performance binder-free electrode materials for supercapacitor applications. The incorporation of cobalt into the SrTiO₃ lattice aims to improve the electrical conductivity of the material and enhance its electrochemical behavior, thereby enabling more efficient charge storage and energy transfer. A facile hydrothermal method was employed for the direct growth of Co-doped SrTiO₃ on Ni foam, which acted as both a structural support and current collector, enabling a binder-free configuration that improved electrical connectivity and active material utilization. The successful formation of the Co-doped SrTiO₃ phase on the Ni foam was confirmed by X-ray diffraction (XRD) analysis, which provided insights into its crystalline structure and phase purity. Further chemical bonding and functional group analyses were performed using Fourier-transform infrared spectroscopy (FTIR), which confirmed the presence of characteristic metal–oxygen stretching vibrations corresponding to the Co–O and Ti–O bonds, supporting the successful doping and incorporation of cobalt into the SrTiO₃ matrix. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses were used to investigate the surface morphology and nanostructure, which revealed a well-defined hierarchical architecture. The electrochemical performance was evaluated in a three-electrode setup using a 1 M Na₂SO₄ aqueous electrolyte. Cyclic voltammetry (CV) revealed prominent redox peaks, confirming the pseudocapacitive nature of the electrode. Galvanostatic charge–discharge (GCD) tests demonstrated a high specific capacitance, while electrochemical impedance spectroscopy (EIS) indicated low internal resistance and good charge-transfer characteristics. Among the prepared samples, NC3 exhibited the best electrochemical performance because it had an optimal amount of cobalt and a well-connected porous structure. NC3 delivered a high specific capacitance of 403.17 F g⁻¹ at a scan rate of 5 mVs⁻¹ and maintained 85.44% capacitance retention after 10,000 cycles, indicating excellent cycling stability. Furthermore, the assembled device achieved a maximum energy density of 15.24 Wh kg⁻¹. These findings highlight that the binder-free, nanostructured Co-doped SrTiO₃ directly grown on Ni foam is promising for use in next-generation high-performance supercapacitors, owing to its enhanced electrical properties and robust structural integrity.