High-performance membrane for vanadium redox flow batteries: Cross-linked poly(ether ether ketone) grafted with sulfonic acid groups via the spacer

Styrene-co-DVB grafted PVDF proton exchange membranes for vanadium redox flow battery applications

“…This low crossover of the VO 2+ ion helps the redox pair to remain in their respective chambers, thus the capacity retention will be higher. Table 3 shows the performance of the prepared membrane in terms of cell efficiency and vanadium permeability compared with membranes reported in the literature, under similar VRFB operating environments, which were comparable to the reported data 28,32,34,[51][52][53] 4. Conclusion DPVDF based St-DVB semi-interpenetrating network type membranes were successfully synthesized via free radical polymerization with various amounts of St and DVB followed by sulfonation using CSA.…”

“…26 Crosslinked PEEK, SPEEK, and polyetherimide (PEI) based zwitterionic membranes showed high ionic conductivity, minimal vanadium permeability, enhanced mechanical strength, and chemical inertness for the VRFB application. 34,35 The vanadium crossover of the membranes was addressed by reducing free volume using a nano-filler, which also enhanced mechanical stability and showed a blocking effect for vanadium ions across the membrane. 36 Modified Nafion membrane has also been studied for the VRFB application using different techniques.…”

A Chemistry and Microstructure Perspective on Ion‐Conducting Membranes for Redox Flow Batteries

“…As mentioned in Section 2.1.1, covalent-crosslinking is as traightforward approach to suppress the excessive swelling of IEMs,b ut is accompanied by adverse effects such as low ionic conductivity.T od isentangle the dilemma, recently,anew cross-linker grafted with -SO 3 Hgroups via aflexible spacer was applied to synthesize across-linked sulfonated poly(ether ether ketone) by Shahi and co-workers (CrSPK-S in Figure 3). [44] In this artful design, the -SO 3 Hg roups on the crosslinker compensate for the consumption of ion exchange groups during the crosslinking process,t hus keeping the density of charged groups constant. As ar esult, the prepared IEM demonstrated adecent comprehensive performance in VRFBs,i .e., high ionic conductivity,h igh chemical stability,r educed swelling ratio along with low vanadium crossover.…”

Advanced Functional Membranes for Energy Applications

“…Membranes containing cationic and anionic selective membranes that have the combined features of AEMs and CEMs are known as amphoteric ion selective membranes (AISMs). CEMs exhibit better resistance to chemical degradation and higher conductivity, while AEMs exhibit lower V cross-over rates [96]. Sulphate and vanadium species can be made less permeable by adding both AEM and CEM properties at the same time [97].…”