ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

CoSe₂-based composite as electrode for hybrid symmetric supercapacitor

Shweta Tanwar, Nirbhay Singh, Ritesh Kumar, Anurag Gaur, and A. L. Sharma

Department of Physics, Netaji Subhas University of Technology, New Delhi, India

E-mail: sh1994t@yahoo.in

Received: 25 March 2026  Accepted: 19 May 2026

Abstract:

The rising worldwide energy need, coupled with the rapid exhaustion of fossil fuels, has intensified the hunt of efficient and maintainable energy storage devices. In this study, the role of post-stability testing on the morphology and the electrochemical characteristics of cobalt selenide (CoSe₂) ternary composites as symmetric supercapacitor electrodes is explored. Excellent theoretical capacitance and good electrical conductivity, which are desirable features in a supercapacitor electrode material, are exhibited by CoSe₂. The ternary composite was prepared via a hydrothermal cum physical blending technique. The Galvanostatic charge-discharge (GCD) tool was used for long-term cycling of the electrodes. It showed a specific capacitance shift from 188 F g⁻¹ to 175 F g⁻¹ at 1 A g⁻¹. Morphological post-cycle analysis showed surface roughening and particle agglomeration, leading to a reduction in conductivity and capacitance. Partial structural transformation was shown by the X-ray diffraction graph. Electrochemical impedance spectroscopy study indicates high charge transfer resistance (increased from 1.8 to 2.7 ohms) and internal resistance after the stability test. Further, red LED glow using both pre- and post-stability-based symmetric cells has been studied. The above discussions bring out the urgent requirement to develop synthesis protocols and practical methods for improving the structural stability and practical relevance of CoSe₂-based electrodes for energy storage applications.

Keywords: Symmetric supercapacitor; Cobalt diselenide; Cyclic stability; Electrochemical

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05088-7

Chemical Papers 80 (10) 11741–11750 (2026)