Novel amphoteric ion exchange membranes by blending sulfonated poly(ether ether ketone)/quaternized poly(ether imide) for vanadium redox flow battery applications

Abstract

For vanadium redox flow battery (VRB) applications, novel amphoteric ion exchange membranes (AIEMs) are prepared using sulfonated poly(ether ether ketone) (SPEEK) and quaternized poly(ether imide) (QAPEI) by a facile method. Different from other AIEMs synthesized by multiple steps, SPEEK/QAPEI (S/Q) membranes are directly prepared by blending. It offers a reduction in cost and leads to a high degree of micro-phase separated structure which could facilitate ion transport. The mechanical properties, thermal stability and oxidative stability of S/Q blend membranes are examined. In addition, increasing the content of QAPEI in the blend membranes could reduce water uptake and vanadium ion permeability effectively and improve the proton selectivity. In VRB single cell tests, the VRBs with S/Q blend membranes show higher coulombic efficiency and energy efficiency (EE) than pristine SPEEK and Nafion 115 membranes.Furthermore, the blend membranes present stable performance up to 100 cycles without significant decline in EE. All experimental results indicate that the S/Q blend membranes show promising prospects for VRB applications.

Electrospun polyacrylonitrile nanofiber mat protected membranes for vanadium flow batteries

“…22,25 Therefore, it is significant to improve the mechanical durability and chemical stability of the SPEEK membrane to meet the demand of VFB. To accomplish this goal, various strategies have been used, such as incorporating inorganic llers, 26,27 blending with other polymers, 28,29 and reinforcing by porous skeletons. 30 Compared with above microscopic modication approaches, macroscopic protection is another effective method.…”

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

“…50 Liu et al reported that SPEEK and quaternized poly(ether imide) could be mixed to prepare AIEMs. 51 The resulting AIEMs exhibited better vanadium ion resistance than SPEEK and Naon117 and maximum EE of 88.45% in VRBs. He's group explored a number of AIEMs obtained from SPEEK and imidazolium-based PSF, which possessed close area resistance and lower vanadium permeability compared with Naon212.…”

“…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.…”

Novel Anion Exchange Membrane Based on Poly(Pentafluorostyrene) Substituted with Mercaptotetrazole Pendant Groups and Its Blend with Polybenzimidazole for Vanadium Redox Flow Battery Applications

“…Open circuit voltage (OCV) measurements can be used to indirectly measure the vanadium ion cross-over [36], as the cross-over through the membrane results in self-discharge, which corresponds to a OCV drop in the performance of the VRFB [37]. Thus, self-discharge was monitored as a function of time.…”