Systematic Characterizations of All-Vanadium Redox Flow Battery Employing Pore-Filled Ion-Exchange Membranes

2015 ◽  
Vol 3 (34) ◽  
pp. 17590-17597 ◽  
Author(s):  
Shuai Liu ◽  
Lihua Wang ◽  
Dan Li ◽  
Biqian Liu ◽  
Jianjun Wang ◽  
...  

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.


Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 867
Author(s):  
Ha-Neul Moon ◽  
Hyeon-Bee Song ◽  
Moon-Sung Kang

In this work, we developed pore-filled ion-exchange membranes (PFIEMs) fabricated for the application to an all-vanadium redox flow battery (VRFB) by filling a hydrocarbon-based ionomer containing a fluorine moiety into the pores of a porous polyethylene (PE) substrate having excellent physical and chemical stabilities. The prepared PFIEMs were shown to possess superior tensile strength (i.e., 136.6 MPa for anion-exchange membrane; 129.9 MPa for cation-exchange membrane) and lower electrical resistance compared with commercial membranes by employing a thin porous PE substrate as a reinforcing material. In addition, by introducing a fluorine moiety into the filling ionomer along with the use of the porous PE substrate, the oxidation stability of the PFIEMs could be greatly improved, and the permeability of vanadium ions could also be significantly reduced. As a result of the evaluation of the charge–discharge performance in the VRFB, it was revealed that the higher the fluorine content in the PFIEMs was, the higher the current efficiency was. Moreover, the voltage efficiency of the PFIEMs was shown to be higher than those of the commercial membranes due to the lower electrical resistance. Consequently, both of the pore-filled anion- and cation-exchange membranes showed superior charge–discharge performances in the VRFB compared with those of hydrocarbon-based commercial membranes.


Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1482 ◽  
Author(s):  
Yu Cui ◽  
Xibang Chen ◽  
Yicheng Wang ◽  
Jing Peng ◽  
Long Zhao ◽  
...  

A series of poly(vinylidene difluoride)-based amphoteric ion exchange membranes (AIEMs) were prepared by preirradiation-induced graft copolymerization of styrene and dimethylaminoethyl methacrylate in an aqueous emulsion media followed by solution casting, sulfonation, and protonation. The effects of absorbed dose and comonomer concentration on grafting yield (GY) were investigated. The highest GY of 44.5% at a low comonomer concentration of 0.9 M could be achieved. FTIR, TGA, and X-ray photoelectron spectroscopy (XPS) confirmed the successful grafting and sulfonation of the as-prepared AIEMs. Properties of the AIEMs such as water uptake, ion exchange capacity (IEC), ionic conductivity, and crossover behavior of VO2+ ions prepared by this novel technique were systematically investigated and compared with those of the commercial Nafion 115 membrane. It was found that at a GY of 28.4%, the AIEMs showed higher IEC and conductivity, lower permeability of VO2+ ions, and a longer time to maintain open circuit voltage than Nafion 115, which was attributed to their high GY and elaborate amphoteric structure. Consequently, this work has paved the way for the development of green and low-cost AIEMs with good performance for vanadium redox flow battery applications.


2016 ◽  
Vol 29 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Ling Zhao ◽  
Fuzhen Li ◽  
Yanqing Guo ◽  
Yilun Dong ◽  
Jinying Liu ◽  
...  

Sulfonated polyether ether ketone (SPEEK)/polyvinylidene fluoride (PVDF) blends are employed to prepare the ion-exchange membranes for vanadium redox flow battery (VRB) application. The addition of the highly crystalline and hydrophobic PVDF effectively confines the swelling behavior of SPEEK. The vanadium ion permeability of SPEEK/PVDF membranes is one order of magnitude lower than that of Nafion117 membrane and SPEEK membrane. In VRB single-cell test, the SPEEK/PVDF binary membranes exhibit higher energy efficiency (EE) than recast SPEEK and Nafion117 at 30 mA cm−2. The blend membrane with 30 wt% of PVDF (S0.7P0.3) shows EE of 83.2% at 30 mA cm−2, which is superior to that of the Nafion117 and recast SPEEK membranes. In the self-discharge test, S0.7P0.3 membrane also possesses twice longer duration in open circuit decay test. These results indicate that the addition of PVDF is a simple and efficient way to improve the ion selectivity of SPEEK. With all the good properties and low cost, the SPEEK/PVDF membranes are expected to have excellent commercial prospects as ion-exchange membranes for VRB system.


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