A hydrocarbon/Nafion bilayer membrane with a mechanical nano-fastener for vanadium redox flow batteries

Abstract

A hydrocarbon/Nafion bilayer membrane is fabricated using a three-dimensionally interlocked interfacial layer for improved cycling durability of VRFBs.

A phosphotungstic acid coupled silica-Nafion composite membrane with significantly enhanced ion selectivity for vanadium redox flow battery

“…6 (b) (particularly, 86.13% at 40 mA cm −2 and 93.66% at 100 mA cm −2 for Nafion-(SN@APTES-PWA) −4.5 wt%, while 82.31% at 40 mA cm −2 and 90.32% at 100 mA cm −2 for recast Nafion). Additionally, the CE increases for both cells with the increased current densities due to the faster charge-discharge at higher current densities, which implies weaker permeation of vanadium ions [53] . Benefiting from the preferable proton conductivity, the voltage efficiency (VE) of Nafion-(SN@APTES-PWA) −4.5 wt%-based VRB shows a higher value than that with recast Nafion.…”

“…In terms of the stability of discharge capacity, the single cell based on recast Nafion shows a quick capacity decay at the beginning of the cycle, which is a frequently encountered problem. The serious issue could be ascribed to the unequal transfer of water molecules and vanadium ions, which may affect the durability of the battery arising from vanadium electrolyte precipitation [53,62] . Yet the single cells based on Nafion-(SN) −4.5 wt% and Nafion-(SN@APTES-PWA) −4.5 wt% perform more stably.…”

Ultra‐High Ion Selectivity of a Modified Nafion Composite Membrane for Vanadium Redox Flow Battery by Incorporation of Phosphotungstic Acid Coupled UiO‐66‐NH2

“…The VRB with Nafion‐(UiO‐66‐NH 2 @PWA)‐3 wt% presents higher charge capacity and discharge capacity versus recast Nafion, and the coulombic efficiency (CE) shows a much higher value due to the suppressed vanadium crossover as displayed in Figure b (particularly, 85.26% at 40 mA cm −2 and 93.28% at 100 mA cm −2 for Nafion‐(UiO‐66‐NH 2 @PWA)‐3 wt%, while 82.17% at 40 mA cm −2 and 90.11% at 100 mA cm −2 for recast Nafion). Besides, the CE increases for both cells with the increased current densities due to the faster charge‐discharge at higher currents, which reveals weak crossing of vanadium ions . Benefiting from the preferable proton conductivity, the voltage efficiency (VE) of Nafion‐(UiO‐66‐NH 2 @PWA)‐3 wt%‐based VRB is higher than the cell with recast Nafion.…”

“…As presented in Figure c, the single cell with recast Nafion shows a quick capacity decay at the beginning of the cycle, which is a frequently encountered problem. The serious issue could be ascribed to the unequal transfer of water molecules and vanadium ions, which may affect the durability of the battery ,. In contrast, the single cell with Nafion‐(UiO‐66‐NH 2 @PWA)‐3 wt% performs more stably.…”

A Study to Enhance the Nitrate-Nitrogen Removal Rate without Dismantling the NF Module by Building a PFSA Ionomer-Coated NF Module

“…It is expected that these PFSA ionomers will be coated on the NF membrane module in a dispersed form in an aliphatic alcohol-water mixture to prevent the permeation of nitrate-nitrogen. In addition, as PFSA ionomers have higher reliability than hydrocarbons in chemical and thermal stability, as demonstrated in several kinds of literature [ 16 ], Nafion dispersions (e.g., 5 wt% Nafion D521, DuPont, USA) are commonly used [ 17 ]. However, Nafion dispersions have difficulties controlling the particle size and dispersibility characteristics, and attempts have been made to control particle size or dispersibility through chemical and physical routes [ 18 ].…”