Wonmi Lee1 Chanho Noh1 Yonjin Chung2 Yongchai Kwon1

1, Seoul National University of Science and Technology, Seoul, , Korea (the Republic of)
2, Korea National University of Transportation, Chungju, , Korea (the Republic of)

In this work, we introduce new electrode catalyst for vanadium redox flow batteries (VRFBs) and new activated organic species and electrode catalyst including improved redox reactivity by adoption of new catalyst for aqueous organic redox flow batteries (AORFBs). First, in terms of the catalysts for VRFB, new hydroxamic acid functionalized carbon nanotube (HAA-CNT) catalyst is suggested to evaluate its impact on redox reactions of vanadium ions and performance of VRFB with comparison with them using pure CNT and carboxylic acid functionalized CNT catalysts [1]. With the associated measurements, it is proved that HAA-CNT indicates excellent catalytic activity and reaction reversibility because of chelation ability of hydroxamic acid included in the HAA-CNT. Second, regarding the activated species for AORFB, modified form of alloxazine (M-Alloxazine) that is initially suggested by Aziz and Gordon group [2] is used as the species and its optimized synthetic conditions are determined with improved redox reactivity and cell potential. According to the related measurements, performance and durability of the AORFB using the species are compatible with previous result [2]. In addition, when the acidified CNT (A-CNT) catalyst is further involved, the redox reactivity and cell potential of the M-Alloxazine is more improved due to electron transfer promoted by proper difference in electronegativity between the M-Alloxazine and A-CNT. The effects of the new electrode catalysts and activated organic species on performance and durability of AORFB and VRFB are more introduced in this MRD meeting presentation.

[1] C. Noh, S. Moon, Y. Chung and Y. Kwon, Journal of Materials Chemistry A, 5, 21334, 2017.
[2] K. Lin, R. Gomez-Bombarelli, E.S. Beh, L. Tong, Q.Chen, A. Valle, A. AspurGuzik, M.J. Aziz, and R.G. Gordon, Nature Energy, 1, 1, 2016.