Poly(phthalazinone ether ketone ketone) anion exchange membranes with pyridinium as ion exchange groups for vanadium redox flow battery applications

Abstract

Poly(phthalazinone ether ketone ketone) anion exchange membranes with pyridinium as anion exchange groups (PyPPEKK) were prepared by reacting chloromethylated poly(phthalazinone ether ketone ketone) membranes with pyridine in solution. The reaction conditions including diluent solvents, pyridine concentration, reaction time and temperature were investigated. Under the optimized reaction condition, PyPPEKK anion exchange membranes with IEC values in the range of 0.96-1.55 mmol g À1 and water uptake in the range of 10.2-16.5% were obtained. The swelling ratio of PyPPEKK membranes in deionized water and VOSO 4 solution were in the range of 3.2-10.6% and 2.5-7.8%, respectively.PyPPEKK membranes showed good chemical stability in VO 2 + solution. Notably, PyPPEKK membranes had higher coulombic efficiencies of VRB and much lower vanadium permeability compared with Nafion117 membrane. The energy efficiency of VRB with PyPPEKK membrane reached 83.6% at 80 mA cm À2 while the energy efficiency of VRB with Nafion117 membrane was 80.7% at the same chargedischarge current density. Furthermore, PyPPEKK membrane exhibited good performance in the 100cycle charge-discharge VRB test.

Poly(phenyl sulfone) anion exchange membranes with pyridinium groups for vanadium redox flow battery applications

“…% solution, the solution was casted onto a smooth glass plate and evaporating the solvent at 60 C for 9 h to obtain base membrane, and then the base membrane was treated with the method according to Zhang et al [28]. The base membrane was immersed in 1 mol L À1 pyridine water solution at 40 C for 72 h to obtain poly(phenyl sulfone) anion exchange membrane with pyridinium groups (PyPPSU) (Scheme 1).…”

“…Anion exchange membranes were obtained by utilizing the high reactivity of the chloromethyl groups with pyridine to form pyridinium groups [28]. The membranes derived from the chloromethylated poly(phenyl sulfone) base membranes were named PyPPSU-1 and PyPPSU-2, respectively ( Table 2).…”

“…Both traditional quaternary ammonium group and pyridinium group can be served as ion exchange groups for anion exchange membrane. Pyridinium group showed more stability than quaternary ammonium group in oxidative vanadium electrolyte [28]. Moreover, pyridinium group, as a weak alkaline, can promote proton transport of membrane due to acidebase interactions [27].…”

Hybrid membranes with low permeability for vanadium redox flow batteries using in situ sol-gel process

“…However, sulfonated aromatic polymer membranes exhibit degradation due to backbone oxidation, which cannot tolerate the cyclic environment in VRFBs [16]. Several research groups have also studied anion exchange membranes as potential membranes for VRFBs due to their low cost and low permeability [17][18][19][20]. However, the low ionic conductivity and stability of anion exchange membranes in VRFBs exhibits low performance.…”

Densely quaternized anion exchange membranes synthesized from Ullmann coupling extension of ionic segments for vanadium redox flow batteries

“…The VO 2+ permeability of the membranes was measured according to a conventional method since it is one of the key parameters for VRFB separators [30,48] ). This is probably because that the ).…”