Investigation on physico-chemical and electrochemical performance of poly(phenylene oxide)-based anion exchange membrane for vanadium redox flow battery systems. (1st December 2019)

• Record Type: Journal Article
• Authors: Roh, Sung-Hee; Lim, Min-Hwa; Sadhasivam, T.; Jung, Ho-Young
• Is Part Of: Electrochimica acta. Volume 325(2019)
• Publication Date: 2019-12-01
• Subjects: Poly(phenylene oxide) -- Anion exchange membrane -- Vanadium redox flow battery -- Permeability -- Donnan exclusion effect; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2019.134944
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Efficient and cost-effective membranes to increase sustainability of electrochemical energy conversion systems consisting of vanadium redox flow batteries (VRFBs) have received wide-range of attention. In this research, to investigate the feasibility of an anion exchange membrane for VRFBs, we fabricated a cost-effective poly(phenylene oxide)-based Im-bPPO membrane through facile preparation techniques. Physico-chemical and electrochemical measurements proved that the Im-bPPO membrane could be considered as a membrane candidate for VRFB applications. The Im-bPPO membrane exhibited good water uptake behavior and an ion exchange capacity of 0.71 meq/g. The anion exchange properties of the Im-bPPO membrane showed a reasonable proton conductivity of 12 mS/cm, which can facilitate proton transportation during unit cell operation. The presence of –OH functional group and water molecules in the membrane can induce proton transportation. Moreover, vanadium (V 4+ ) ion crossover was significantly prohibited by the Im-bPPO membrane, which was considerably lower than the Nafion membrane. Vanadium permeability of the Im-bPPO membrane is 0.0678 × 10 −7 cm 2 min −1 . A unique advantage of the Im-bPPO membrane is raising the Donnan exclusion effect during the unit cell operation, where the same charge of vanadium ion is repulsed by the Im-bPPO membrane. Furthermore, a reasonable VRFB unit cell performance was obtained by the Im-bPPO membrane. The coulombic efficiency of the Im-bPPO membrane (99.5%) is higher than that of the Nafion membrane (93%) under identical conditions during the 5th cycle, which can enhance the overall VRFB performance. This research work provides an insight into Im-bPPO-based anion exchange membranes for VRFB systems. Graphical abstract: Image 1 Highlights: A cost-effective poly(phenylene oxide)-based Im-bPPO membrane for VRFB. Vanadium permeability of the Im-bPPO membrane is lower. The Im-bPPO membrane exhibited higher selectivity than the Nafion membrane. Coulombic efficiency of Im-bPPO membrane is higher than Nafion membrane. Unique advantage of Im-bPPO membrane is raising the Donnan exclusion effect.