Preparation and characterization of quaternized poly (2,2,2‐trifluoroethyl methacrylate‐co‐N‐vinylimidazole) membrane for vanadium redox flow battery

Abstract

Aiming to develop a suitable ion exchange membrane for vanadium redox flow battery (VRB), a new kind of imidazolium salt type anion exchange membrane based on the copolymer of N‐vinylimidazole and 2,2,2‐trifluoroethyl methacrylate has been prepared. The membrane is characterized by means of water uptake, ion‐exchange capacity, ionic conductivity, and thermal stability. Furthermore, a VRB with this membrane is assembled, and the performance of such VRB is evaluated. The permeability experiments show that this membrane has reasonable low permeability of vanadium ions. The coulombic efficiency (CE) and energy efficiency (EE) of VRB with the synthesized membrane are 99.5% and 75.0%, whereas the CE and EE of the VRB with Nafion® 117 membrane are 82.6% and 72.6%, respectively. The synthesized membrane shows good chemical stability in VRB via more than 4000 cycles test. Therefore, this membrane shows good applicable potential in VRB. Copyright © 2012 John Wiley & Sons, Ltd.

Novel sulfonated polyimide/ZrO2composite membrane as a separator of vanadium redox flow battery

“…Permeability of vanadium ions was measured by a method similar to that of the literature . The sample solution from right reservoir was measured at a regular time, and the concentration of VO 2+ was determined by ultraviolet–visible spectroscopy (UV‐1100, MAPADA, Shanghai, China).…”

Composite anion exchange membranes based on quaternized cardo-poly(etherketone) and quaternized inorganic fillers for vanadium redox flow battery applications

“…When the current density was increased, it took less time for a full charge or discharge in the VRFBs, which resulted in higher CEs. The retention time for a single charge-discharge cycle is a dominant factor that determines the CE in a VRFB system [34]. Longer times to charge and discharge the battery leads to more cation (vanadium) cross-mixing via transport through the membrane separator.…”

“…poly(arylene ether) [20], poly(fluorenyl ether) [27], poly(ether ether ketone) [28], poly(ether sulfone) [29], polysulfone [22,30], poly(phthalazinone ether ketone) [31], poly(phthalazinone ether ketone ketone) [32], poly(tetramethydiphenyl ether ether ketone) [25], and cardo-poly(ether ketone) (PEK-C) [33]. Several efforts have been made to achieve the desired properties by employing: (a) copolymers, and (b) organic/inorganic composite membranes [4,13,[34][35][36].…”

“…They found that the proton conductivity increased from 76 to 131 mS cm -1 when the block length (of the BPSH-BPS block copolymer) increased from 3000 to 10,000 g mol -1 . Fang et al prepared AEMs based on copolymers of N-vinylimidazole and 2,2,2-trifluoroethylmethacrylate and tested them in a VRFB obtaining EEs of 75% at a current density of 50 mA cm -2 ; Under similar conditions, Nafion ® 117 resulted in an EE of 72.6% [34].…”

“…Li et al prepared organic/inorganic composite AEMs with quaternized poly(arylene ether sulfone) (QPAES) and ZrO 2 filler, and demonstrated that the ZrO 2 crystalline phase facilitated the formation of ionic channels in the hydrated membranes due to the fixed functional groups on the crystalline phase [24]. The hydroxide conductivity increased from 9.5±0.6 mS cm -1 for the non-modified polymer to 23.1±2.1 mS cm -1 for the composite membrane with 10 wt% [34] and poly(tetrafluoroethylene) [43] for use as separators in VRFBs. When employing these composite membrane as separators in a VRFB, their observed EE was approximately 80% , and the battery capacity remained constant over 40 charge-discharge cycles.…”