Abbas, Saleem Sheeraz, Mehboob Shin, Hyun Jin Syed Bilal Hasan Rizvi Kim, Jaewon Henkensmeier, Dirk Ha, Heung Yong 2024-01-12T06:34:56Z 2024-01-12T06:34:56Z 2023-05-08 2023-08 0169-4332 https://pubs.kist.re.kr/handle/201004/79869 The surface chemistry of carbon electrodes plays a vital role towards the kinetics of vanadium redox reactions of vanadium redox flow batteries (VRFB). In this study, O2, CO2, N2, and NH3 plasmas have been employed to modify the surface chemistry of graphite felt electrodes, and the effect of various surface functional groups on negative and positive electrode reactions of VRFB has been explored. Various analytical techniques, electrochemical characterizations and asymmetric charge？discharge experiments reveal that the surface functional groups have a specific role towards vanadium redox reactions on each side of a VRFB cell. The C=O and O-C=O groups show catalytic effects while the C-O group has an inhibiting effect on the kinetics of negative and positive electrode reactions. Pyrrolic-N shows catalytic effects on the positive electrode reactions whereas oxidized-N has catalytic effects on the negative electrode reactions. Amine groups introduced by NH3 plasma worsen the sluggish kinetics of the negative electrode reactions by boosting hydrogen evolution reaction. Based on the specific behavior, an optimal arrangement of each plasma-treated felt has also been proposed by either utilizing it as negative electrode, positive electrode or both in a VRFB cell, leading to an overall improved performance. English Elsevier BV Tunable surface chemistry of carbon electrodes and the role of surface functionalities towards vanadium redox reactions Article 10.1016/j.apsusc.2023.157331 1 Applied Surface Science, v.628 Applied Surface Science 628 Y scie scopus 000990773400001 Chemistry, Physical Materials Science, Coatings & Films Physics, Applied Physics, Condensed Matter Chemistry Materials Science Physics Article FENTONS REAGENT TREATMENT GRAPHITE FELT ELECTRODES FLOW BATTERY APPLICATION ELECTROCHEMICAL PERFORMANCE POSITIVE ELECTRODE NEGATIVE ELECTRODE FIBER ELECTRODES GRAPHITIZATION GRAPHENE Vanadium redox flow battery Plasma treatment Surface chemistry Carbon electrode Ammonia plasma CO2 plasma