Electrochemical investigations of rare earth orthochromite (SmCrO₃) nanosponges for energy storage application

Abstract In this study, the electrochemical energy storage capability of hydrothermally synthesized samarium chromite (SmCrO₃) nanoparticles was thoroughly investigated, highlighting their potential application as electrode material in supercapacitor. Comprehensive structural, optical, morphological, and functional analyses were conducted using x-ray diffraction, UV-visible spectroscopy, Fourier-transform infrared spectroscopy, Photoluminescence spectroscopy, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy to confirm the successful formation of SmCrO₃ nanoparticles. The electrochemical performance was evaluated in a three-electrode configuration employing 1 M KOH as the aqueous electrolyte, where cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy were carried out. The SmCrO₃ nanoparticle electrode exhibited a high Cs of 1264.2 Fg⁻¹ at a scan rate of 4 mVs⁻¹, along with an energy density of 573.7 Whkg⁻¹ and a power density of 18 775 Wkg⁻¹, indicating excellent pseudocapacitive behavior. Furthermore, the synthesized electrode demonstrated outstanding cycling stability, retaining 93% of its initial capacitance even after 1000 charge-discharge cycles. These findings suggest that SmCrO₃ nanoparticles are a promising candidate for advanced supercapacitor applications, offering a favorable combination of high electrochemical performance and long-term stability.