Vol.:(0123456789) 1 3 Journal of the Korean Ceramic Society (2020) 57:585–596 https://doi.org/10.1007/s43207-020-00057-6 ORIGINAL ARTICLE Surface modifcation and electrochemical per formance of KMnO 4 ‑ultra‑surface area activated carbon (USAC) composites as cathode material Zambaga Otgonbayar 1  · K amrun Nahar Fatema 1  · Md Nazmodduha Rafat 1  · Jihyeon Ryu 4  · Sun‑Hye Yang 2  · Ick‑Jun Kim 2  · Won‑Chun Oh 1,3 Received: 14 March 2020 / Revised: 30 April 2020 / Accepted: 6 May 2020 / Published online: 20 May 2020 © The Korean Ceramic Society 2020 Abstract The goal of this study was to analyse the impact of a combination of a sub-active material (KMnO 4 ) with surface modifca- tion to the activated carbon surface for enhanced cathode performance. Activated carbon with ultra-specifc surface area (USAC, TCK-PBM, 2560.4 m 2 /g) was used for the preparation of our composite with potassium permanganate (KMnO 4 ). The physical characteristics of this As-treated USAC sample were analysed through XRD, SEM and EDX analysis. The XRD analysis was used to examine structural properties; surface analysis undertaken by SEM; EDX analysis was used to measure the metal content of the sample as well as the content after treatment with KMnO 4 . It was shown USAC treated with KMnO 4 had more than a 10.5 μg acidic group by the Boehm titration method. The electrochemical properties of KMnO 4 -USAC were investigated for varying electrolyte concentration (0.1, 0.5, 1.2 and 6 M) at ambient temperature (25 °C) and the electrode showed great electrochemical performance after ten cycles. Keywords Ultra-surface area activated carbon (USAC) · Sub-active material · Secondary battery electrode · Electrochemical performance 1 Introduction Activated carbon is a type of graphitic material, it has high specifc sur face area, good porosity, low preparation cost and its raw material is plentiful. In addition, activated car- bon has shown high stability in acidic conditions [1–3]. Carbon-based materials have been used as electrode mate- rials for decades [4, 5]. The properties of activated carbon themselves can be modifed to develop several advantageous activation characteristics. The modifcation of AC alters the exterior of the carbon and improves its surface area and porous structure [6–8]. Graphitic materials are mostly used as high-capacity electrode materials. Some researchers syn- thesize carbon-based electrodes with some transition metals [9], but these kinds of materials still have some problems such as high price, insufcient electrochemical stability and the fact they block ion-transfer in the pore structure of the trans-metal covered carbon material. When it comes to enhancing the properties of activated carbon, surface mod- ifcation is one of most widely used method, specifcally there have been many attempts to create an artifcial layer on the exterior of active-material to prevent any side reac- tion mechanism between the electrode and electrolyte, if this attempt is successful the result is good long-term cycling performance. Surface modifcation generally uses chemical reagents such as H 2 O 2 , NaOH among others [10–12], this is due to the diferent requirements for the chemical activity of activated carbon [13–15]. Among these reagents, potassium permanganate (KMnO 4 ) has shown good properties such as being * Won-Chun Oh wc_oh@hanseo.ac.kr 1 Department of Advanced Materials Science and Engineering, Hanseo University, Seosan-si 356-706, Chungnam, Korea 2 Korea Electrotechnology Research Institute, Changwon-si 641-120, Kyungnam, Korea 3 College of Materials Science and Engineering, Anhui University of Science and Technology, Huainan 232001, People’s Republic of China 4 Department of Electro-Functionality Materials Engineering, University of Science and Technology (UST), Daejeon 34113, Republic of Korea