A low vanadium permeability sulfonated polybenzimidazole membrane with a metal-organic framework for vanadium redox flow batteries. (10th February 2022)

• Record Type: Journal Article
• Authors: Liang, Dan; Wang, Shuang; Ma, Wenjia; Wang, Di; Liu, Geng; Liu, Fengxiang; Cui, Yinghe; Wang, Xiaodong; Yong, Zhipeng; Wang, Zhe
• Is Part Of: Electrochimica acta. Volume 405(2022)
• Publication Date: 2022-02-10
• Subjects: Metal-organic framework -- Vanadium redox flow battery -- Low vanadium transmittance -- Sulfonated polybenzimidazole; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.139795
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: Controllable degree of sulfonated polybenzimidazole membrane was prepared for VRFB. H + /V n+ sieving was achieved by appropriate pore size (0.55 nm) of MOF. High conductivity and low area resistance were achieved. 4.VRFB shows improved efficiency and long-term cycle stability. Abstract: A proton selective membrane based on a metal-organic framework (MOF) and polybenzimidazole (PBI) with a controllable sulfonation degree is designed for vanadium redox flow battery (VRFB) applications. The size of UiO-66 is between hydrated multivalent vanadium ions and stokes radius of protons, and its suitable pore size can obstruct the penetration of vanadium ions, resulting in a high vanadium resistance rate. Simultaneously, the imidazole groups and sulfonic acid groups in the sulfonated polybenzimidazole compose the acid-base pairs, which block the penetration of vanadium ions. Therefore, sulfonated PBI together with UiO-66 forms a denser network structure for as a vanadium ion barrier. Compare with the Nafion117 film, the vanadium transmittance of prepared composite film is lower (5.15 × 10 −7 cm 2 min −1 vs. 2.95 × 10 −9 cm 2 min −1 ). Compare with the Nafion117 membrane, VRFB with MOF polymer exhibits higher voltage efficiency (94.54%–74.93%) and energy efficiency (84.82%–73.98%) at 40-200 mAcm −2 . Graphical Abstract: Image, graphical abstract