Chen, Ruiyong Henkensmeier, Dirk Kim, Sangwon Yoon, Sang Jun Zinkevich, Tatiana Indris, Sylvio 2024-01-19T21:32:14Z 2024-01-19T21:32:14Z 2021-09-04 2018-11 2574-0962 https://pubs.kist.re.kr/handle/201004/120754 Through controlling the cross-linking and thickness of low-cost methylated polybenzimidazole anion exchange membranes and by using imidazolium chloride as a catholyte additive, we improved the energy efficiency at a current density of 100 mA cm(-2) for all-vanadium redox flow batteries (RFBs) to 82%, compared to 76% with a Nafion 212 membrane and 6778% for previously reported polybenzimidazole membranes with standard electrolyte. Moreover, thermal stability analysis of the charged catholytes, by direct observations of vanadium precipitation and variable temperature V-51 nuclear magnetic resonance, confirmed an optimized content of 0.16 M of the electrochemically inert additive in 1.6 M vanadium solution, consistent with the electrochemical data. The imidazolium chloride additive with such a low concentration is sufficient to induce interaction with vanadium species in catholyte. This explains the improved electrolyte stability and enhanced cycling efficiency. English AMER CHEMICAL SOC Improved All-Vanadium Redox Flow Batteries using Catholyte Additive and a Cross-linked Methylated Polybenzimidazole Membrane Article 10.1021/acsaem.8b01116 1 ACS APPLIED ENERGY MATERIALS, v.1, no.11, pp.6047 - 6055 ACS APPLIED ENERGY MATERIALS 1 11 6047 6055 N scopus 000458706700033 2-s2.0-85058163681 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Chemistry Energy & Fuels Materials Science Article ION-EXCHANGE MEMBRANES HIGH-ENERGY DENSITY POSITIVE ELECTROLYTE HIGHLY EFFICIENT SELECTIVITY GENERATION STABILITY CAPACITY LINKING BLENDS energy storage redox flow batteries vanadium electrolyte imidazolium chloride temperature stability