Journal of Physics and Chemistry of Solids 180 (2023) 111473 Available online 27 May 2023 0022-3697/© 2023 Elsevier Ltd. All rights reserved. Growth of AgCoS@CNTs composite on nickel foam to enrich the redox active sites for battery-supercapacitor hybrid energy storage device A Al Ojeery a, * , Haseeb ul Hassan b , S.A. Al Balawi a , Muhammad Waqas Iqbal b, ** , Amir Muhammad Afzal b , N.M.A. Hadia c a Department of Physics, College of Science, University of Jeddah, Jeddah, Saudi Arabia b Department of Physics, Riphah International University, Campus Lahore, Pakistan c Physics Department, College of Science, Jouf University, Al-Jouf, Sakaka, P.O. Box 2014, Saudi Arabia A R T I C L E INFO Keywords: Energy storage devices Asymmetric devices Carbon nanotube Silver cobalt sulfde Supercapattery ABSTRACT Supercapacitors are recognized as reliable energy storage technologies, despite obstacles such as inadequate energy density and comparatively small capacitance. In this study, we employed a hydrothermal synthesis method to fabricate silver cobalt sulfde (AgCoS) and doped it with carbon nanotubes (CNTs). The surface area of 19.35 m 2 /g was achieved with AgCoS@CNT//AC using BET measurements. The galvanostatic charge-discharge (GCD) measurements revealed a specifc capacity of 1023 C/g for AgCoS@CNT. To construct an asymmetric device (AgCoS@CNT//AC), the best-performing AgCoS@CNT composite was employed as the positive electrode, while activated carbon (AC) served as the negative electrode. The specifc capacity of the asymmetric device AgCoS@CNT//AC was measured to be 104 C/g, accompanied by a high power density of 750 W/kg and an impressive energy density of 32 Wh/kg. Notably, the columbic effciency of the AgCoS@CNT//AC device reached 100% after 5000 consecutive cycles, while maintaining a capacity retention of 82%. These fndings indicate that the AgCoS@CNT composite might serve as an intriguing material as an electrodes for super- capacitor applications. Author contribution A Al-Ojeery, M. waqas Iqbal, Haseebul Hassan, worked on experi- ments, data collection, analysis, and interpretation of results. S. A. Al- Balawi, M. waqas Iqbal and N.M.A. Hadia performed the calculation and wrote the manuscript. Amir Muhammad Afzal, Haseebul Hassan helped with the calculation and reviewed the manuscript. All the au- thors read the approved fnal manuscript. 1. Introduction Due to the scarcity of fossil fuels and worry about climate change, there is an immediate need to develop alternative energy resources and innovative practices related to energy conversion and storage [1]. Since electrochemical energy conversion and storage technologies are currently quite practical, supercapacitors (SCs) and electrolysis of water splitting have attracted much interest [2–5]. The development of electrochemical storage technologies, such as batteries, SCs, and fuel cells, has considerably increased the energy supply for smart devices and electric cars [6–8]. Superior power density, extended cyclic stability, and safe usage are all features of supercapacitors. Reducing the energy density of supercapacitors in aqueous electrolytes is one of their main issues [9–11]. Additionally, certain electrode materials can provide hybrid capac- itance, which combines fast reversible faradaic dynamics (pseudocapa- citance) with surface ion adsorption to give the desired characteristics of a quick charge/discharge mechanism, high power density, and extended lifetime [6,12]. Nanocomposites with hierarchical structures have been used extensively in electrochemical applications [13–15]. In contrast to bulk structures, these complicated mixed nanomaterials have a sub- stantial particular surface area that allows active species transport with rapid succeeding surface kinetics [16–18]. Graphene, conducting polymers, activated carbon, NiO, V 2 O 5 , RuO, Co 3 O 4, and MnO 2 are extensively studied as electrode materials for SC * Corresponding author. ** Corresponding author. E-mail addresses: aaalaegiry@uj.edu.sa (A.A. Ojeery), waqas.iqbal@riphah.edu.pk (M.W. Iqbal). Contents lists available at ScienceDirect Journal of Physics and Chemistry of Solids journal homepage: www.elsevier.com/locate/jpcs https://doi.org/10.1016/j.jpcs.2023.111473 Received 29 March 2023; Received in revised form 8 May 2023; Accepted 26 May 2023