A novel amphoteric ion-exchange membrane prepared by the pore-filling technique for vanadium redox flow batteries

Abstract

A novel amphoteric ion-exchange membrane (AIEM) was prepared through the pore-filling technique, for vanadium redox flow battery (VRBs) applications. Their physico-chemical properties including vanadium ion permeability and electrochemical properties were investigated as a function of cross-linking degrees. Vanadium ion permeability was effectively suppressed by the quaternary ammonium group-induced Donnan exclusion effect and was only 7.7% of that of Nafion117. Finally, open circuit voltage measurements showed that VRBs assembled with the AIEM maintained voltages >1.3 V for over 43 h, which was superior to the cation exchange membranes (CEMs), studied. In addition, the VRBs with AIEM-4 exhibited higher columbic efficiency (ca. 98%) and energy efficiency (ca. 89%) than those with CEMs. Therefore, it may be concluded that pore-filled AIEMs are more suitable for use in VRBs than pore-filled CEMs. This work provides a convenient method for preparing new types of IEMs for various applications.

Improved chemical stability and proton selectivity of semi‐interpenetrating polymer network amphoteric membrane for vanadium redox flow battery application

“…Obviously, the amphoteric membranes exhibit much better resistance to VO 2+ than SPAES and Nafion117. The lower vanadium ions permeability of amphoteric membranes could be explained by the formal comments reported elsewhere 49–51 . The vanadium ion permeability of SPAES membrane (10.9 × 10 −7 cm 2 min −1 ) is lower than that of Nafion117 (21.1 × 10 −7 cm 2 min −1 ) because the channels of SPAES membrane are narrower and more branched than that of Nafion117, due to the higher dispersed sulfonic groups and the unapparent hydrophilic/hydrophobic microphase separation of SPAES.…”

“…The lower vanadium ions permeability of amphoteric membranes could be explained by the formal comments reported elsewhere. [49][50][51] The vanadium ion permeability of SPAES membrane (10.9 × 10 −7 cm 2 min −1 ) is lower than that of Nafion117 (21.1 × 10 −7 cm 2 min −1 ) because the channels of SPAES membrane are narrower and more branched than that of Nafion117, due to the higher dispersed sulfonic groups and the unapparent hydrophilic/hydrophobic microphase separation of SPAES. As shown in Scheme 4, the Donnan exclusion effect of imidazolium cations can limit vanadium ion permeating through amphoteric membranes.…”

A review of all‐vanadium redox flow battery durability: Degradation mechanisms and mitigation strategies

“…In order to reduce the cost and extend the lifetime of VRFB membranes, great efforts have been made by researchers in the VRFB research and development community. In addition to modifying Nafion membranes, alternative membranes have also been developed, including other polymeric CEMs, such as polyether ether ketone (PEEK) and sulfonated diels‐alder poly (phenylene), AEMs, amphoteric ion exchange membranes, and microporous separators such as Daramic membranes and Amer‐Sil membranes . Even if modifying Nafion membranes could enhance the chemical stability, it would not reduce the overall cost of the membrane itself; thus, research efforts are being focused on alternative perfluorinated acid membranes, new anion‐exchange membranes, and other types of polymer membranes.…”

Sulfonated component-incorporated quaternized poly(phthalazinone ether ketone) membranes with improved ion selectivity, stability and water transport resistance in a vanadium redox flow battery

“…Compared with Naon117, the resulting AIEM exhibited 92.3% decrease in vanadium ion permeability. 34 Layer-by-layer self-assembly was also employed to fabricate AIEMs. 35,36 The performance of the resulting AIEMs depended on the count of bilayers for negatively and positively charged polymers.…”

“…The VRB performance of Q/S-x was compared with that of various AIEMs reported in the current literatures. 32,34,37,39,[46][47][48][50][51][52][53][74][75][76][77][78][79] At both low and high currents, Q/S-1.37 exhibited increased CE (>96.0%), thus revealing good vanadium ion resistance. Despite varied experimental conditions in different labs, the VE and EE values of Q/S-1.37 at both low and high currents remained at a relatively high level.…”