Synthesis and fabrication of CoS-embedded AC nanocomposites for an efficient asymmetric supercapacitor application

Natesan K.; Rengarajan S.K.; Cohaila A.B.Q.; Pichan K.; Sacari Sacari E.J.; Viswanathan M.R. · Journal of Materials Science: Materials in Electronics (2026) · DOI: 10.1007/s10854-026-17391-w

Resumen

Recent research has emphasized the potential of combining different electrode materials to enhance the performance of asymmetric supercapacitors for energy storage applications. In this study, an asymmetric supercapacitor was developed using cobalt sulfide (CoS)-embedded activated carbon (AC), denoted as CoS@AC, as the positive electrode, while AC alone served as the negative electrode. Initially, micro-flower morphology of CoS was synthesized via a hydrothermal method, and layered morphology of AC was prepared through the carbonization of Acorus calamus. Then CoS@AC nanocomposite was fabricated using a wet impregnation method and its structural, morphological analysis was carried out. The morphological analysis of CoS@AC nanocomposites confirmed the presence of both micro-flower morphology of CoS and layered morphology of AC structures. The TEM analysis of CoS@AC nanocomposite revealed the presence of both micro-flower-like (CoS) and layered-like structure (AC), and the HRTEM analysis showed an interplanar spacing of 0.236 nm related to CoS (101) XRD diffraction. The BET analysis of CoS@AC nanocomposites shows a nearly type-I isotherm with a surface area of about 1145 m2/g, an average pore size of about 4.23 nm, and a pore volume of 0.451 cc/g. Finally, the CoS@AC‖AC electrode demonstrated enhanced electrochemical performance, achieving a specific capacitance of approximately 234 F/g, an energy density of 83.2 Wh/kg, and a power density of 16,089 W/kg. Further, the stability analysis was carried out for 2000 cycles, which showed better stability performance. These results strongly recommend that the CoS@AC‖AC system is favorable for asymmetric supercapacitor applications. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026.

Instituciones: Universidad Nacional de Ingeniería; Universidad Nacional Jorge Basadre Grohmann