Bui, Trung Tuyen Mingyu Shin Yongchai Kwon Henkensmeier, Dirk 2024-11-04T12:30:14Z 2024-11-04T12:30:14Z 2024-10-31 2024-08-22 https://pubs.kist.re.kr/handle/201004/150951 https://www.mcare2024.org/03web03.php Vanadium redox flow battery is one of the best options to store intermittent renewable energy because it demonstrates intrinsic safety, long lifespan, scalability, and high recyclability.[1] Although Nafion membrane is commonly used in VRFBs to separate anolyte and catholyte, it is expensive and exhibits high vanadium crossover.[2] Herein, we present an alternative novel polybenzimidazole based trilayer membrane assembly for use in VRFBs. The assembly consists of a highly selective 1 ？m thin cross-linked poly[2,2’-(p-oxydiphenylene)-5,5’- bibenzimidazole] (OPBI) membrane sandwiched between two highly conductive 20 ？m thick porous OPBI membranes (p-OPBI) as protective layers. Notably, this trilayer membrane assembly exhibits remarkable properties including high conductivity and a low area specific resistance (ASR) of 51 mS cm-1 and 81 mΩ cm2 , respectively. In contact with vanadium electrolyte, the ASR of the membrane assembly only increases to 158 mΩ cm2 , whereas the ASR of Nafion reaches 193 mΩ cm2 . VO2+ permeability is 2.73x10-9 cm2 min-1 , about 150 times lower than that of Nafion NR212. In addition, the membrane exhibits remarkable mechanical robustness and high chemical stability against VO2 +. In the VRFB, the low resistance and low vanadium permeability translates into excellent performance, revealing high coulombic efficiency (CE) (> 99%), high energy efficiency (EE) at the world level (90.8% at current density of 80 mA cm-2 ), and long-term durability.[3] English KICHE & The American Ceramic Society Trilayer polybenzimidazole membrane assembly for highly efficient vanadium redox flow batteries Conference 1 MCARE 2024 (Materials Challenges in Alternative and Renewable Energy 2024) MCARE 2024 (Materials Challenges in Alternative and Renewable Energy 2024) KO Jeju, South Korea 2024-08-19 Abstracts