Proton Conducting Organic-Inorganic Composite Membranes for All-Vanadium Redox Flow Battery.

Content Provider	Europe PMC
Author	Sreenath, Sooraj Sreelatha, Nayanthara P. Pawar, Chetan M. Dave, Vidhiben Bhatt, Bhavana Borle, Nitin G. Nagarale, Rajaram Krishna
Editor	Henkensmeier, Dirk
Copyright Year	2023
Abstract	The quest for a cost-effective, chemically-inert, robust and proton conducting membrane for flow batteries is at its paramount. Perfluorinated membranes suffer severe electrolyte diffusion, whereas conductivity and dimensional stability in engineered thermoplastics depend on the degree of functionalization. Herein, we report surface-modified thermally crosslinked polyvinyl alcohol-silica (PVA-SiO2) membranes for the vanadium redox flow battery (VRFB). Hygroscopic, proton-storing metal oxides such as SiO2, ZrO2 and SnO2 were coated on the membranes via the acid-catalyzed sol-gel strategy. The membranes of PVA-SiO2-Si, PVA-SiO2-Zr and PVA-SiO2-Sn demonstrated excellent oxidative stability in 2 M H2SO4 containing 1.5 M VO2+ ions. The metal oxide layer had good influence on conductivity and zeta potential values. The observed trend for conductivity and zeta potential values was PVA-SiO2-Sn > PVA-SiO2-Si > PVA-SiO2-Zr. In VRFB, the membranes showcased higher Coulombic efficiency than Nafion-117 and stable energy efficiencies over 200 cycles at the 100 mA cm−2 current density. The order of average capacity decay per cycle was PVA-SiO2-Zr < PVA-SiO2-Sn < PVA-SiO2-Si < Nafion-117. PVA-SiO2-Sn had the highest power density of 260 mW cm−2, while the self-discharge for PVA-SiO2-Zr was ~3 times higher than Nafion-117. VRFB performance reflects the potential of the facile surface modification technique to design advanced membranes for energy device applications.
Volume Number	13
PubMed Central reference number	PMC10303046
Issue Number	6
PubMed reference number	37367778
Journal	Membranes (Basel)
e-ISSN	20770375
DOI	10.3390/membranes13060574
Language	English
Publisher	MDPI
Publisher Date	2023-06-01
Access Restriction	Open
Rights License	Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). © 2023 by the authors.
Subject Keyword	polyvinyl alcohol silica sol-gel metal oxide tin dioxide zirconium dioxide proton-conducting membrane vanadium redox flow battery
Content Type	Text
Resource Type	Article
Subject	Chemical Engineering Process Chemistry and Technology Filtration and Separation