Preparation of covalently cross-linked sulfonated polybenzimidazole membranes for vanadium redox flow battery applications (original) (raw)
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Composite Polybenzimidazole Membrane with High Capacity Retention for Vanadium Redox Flow Batteries
Molecules
Currently, energy storage technologies are becoming essential in the transition of replacing fossil fuels with more renewable electricity production means. Among storage technologies, redox flow batteries (RFBs) can represent a valid option due to their unique characteristic of decoupling energy storage from power output. To push RFBs further into the market, it is essential to include low-cost materials such as new generation membranes with low ohmic resistance, high transport selectivity, and long durability. This work proposes a composite membrane for vanadium RFBs and a method of preparation. The membrane was prepared starting from two polymers, meta-polybenzimidazole (6 μm) and porous polypropylene (30 μm), through a gluing approach by hot-pressing. In a vanadium RFB, the composite membrane exhibited a high energy efficiency (~84%) and discharge capacity (~90%) with a 99% capacity retention over 90 cycles at 120 mA·cm−2, exceeding commercial Nafion® NR212 (~82% efficiency, capa...
Preparation of sulfonated composite membrane for vanadium redox flow battery applications
Journal of Membrane Science, 1995
In the present studies, Daramic, which consists of ultrahighmolecular polyethylene, amorphous silica and mineral oil, was crosslinked with divinylbenzene (DVB) as a crosslinking agent and further sulfonated to obtain a cation exchange membrane for the vanadium redox cell. It was shown that the average pore size of Daramic was reduced from 0.1 to 0.02 /~m after crosslinking . The preparation and characterisation of the modified ion exchange membrane from the composite membrane with subsequent sulfonation are described. The membrane modification process results in a dramatic reduction in solvent transfer across the membrane when used in the vanadium redox cell. The ion exchange capacity (IEC) of the sulfonated composite membrane was also evaluated. The sulfonation reaction was found to be able to incorporate cation exchange groups into the composite membrane. Water transport measurements across the sulfonated composite membrane showed promising results compared with those across the composite membrane. A detailed FESEM and ~3C NMR analysis of the composite membrane and the sulfonated composite membrane have been carried out.
Highly conductive and low vanadium permeable crosslinked sulfonated poly(ether ether ketone) (cSPEEK) membranes were prepared by electrophilic aromatic substitution for a Vanadium/Air Redox Flow Battery (Vanadium/Air-RFB) application. Membranes were synthesized from ethanol solution and crosslinked under different temperatures with 1,4-benzenedimethanol and ZnCl 2 via the Friedel-Crafts crosslinking route. The crosslinking mechanism under different temperatures indicated two crosslinking pathways: (a) crosslinking on the sulfonic acid groups; and (b) crosslinking on the backbone. It was observed that membranes crosslinked at a temperature of 150°C lead to low proton conductive membranes, whereas an increase in crosslinking temperature and time would lead to high proton conductive membranes. High temperature crosslinking also resulted in an increase in anisotropy and water diffusion. Furthermore, the membranes were investigated Membranes 2014, 4 2 for a Vanadium/Air Redox Flow Battery application. Membranes crosslinked at 200°C for 30 min with a molar ratio between 2:1 (mol repeat unit:mol benzenedimethanol) showed a proton conductivity of 27.9 mS/cm and a 100 times lower VO 2+ crossover compared to Nafion.
Membranes, 2013
Highly conductive and low vanadium permeable crosslinked sulfonated poly(ether ether ketone) (cSPEEK) membranes were prepared by electrophilic aromatic substitution for a Vanadium/Air Redox Flow Battery (Vanadium/Air-RFB) application. Membranes were synthesized from ethanol solution and crosslinked under different temperatures with 1,4-benzenedimethanol and ZnCl 2 via the Friedel-Crafts crosslinking route. The crosslinking mechanism under different temperatures indicated two crosslinking pathways: (a) crosslinking on the sulfonic acid groups; and (b) crosslinking on the backbone. It was observed that membranes crosslinked at a temperature of 150°C lead to low proton conductive membranes, whereas an increase in crosslinking temperature and time would lead to high proton conductive membranes. High temperature crosslinking also resulted in an increase in anisotropy and water diffusion. Furthermore, the membranes were investigated Membranes 2014, 4 2 for a Vanadium/Air Redox Flow Battery application. Membranes crosslinked at 200°C for 30 min with a molar ratio between 2:1 (mol repeat unit:mol benzenedimethanol) showed a proton conductivity of 27.9 mS/cm and a 100 times lower VO 2+ crossover compared to Nafion.
Polymers, 2020
In order to evaluate the performance of the anion exchange membranes in a vanadium redox flow battery, a novel anion exchange polymer was synthesized via a three step process. Firstly, 1-(2-dimethylaminoethyl)-5-mercaptotetrazole was grafted onto poly(pentafluorostyrene) by nucleophilic F/S exchange. Secondly, the tertiary amino groups were quaternized by using iodomethane to provide anion exchange sites. Finally, the synthesized polymer was blended with polybenzimidazole to be applied in vanadium redox flow battery. The blend membranes exhibited better single cell battery performance in terms of efficiencies, open circuit voltage test and charge-discharge cycling test than that of a Nafion 212 membrane. The battery performance results of synthesized blend membranes suggest that those novel anion exchange membranes are promising candidates for vanadium redox flow batteries.
J. Mater. Chem. A, 2013
Synthesis of chloromethylated polysulfone (CMPSF) and PSF-TMA + Cl-. CMPSF was synthesized via the Friedel-Crafts reaction following the procedure described by Avram and coworkers. 1 Details describing the chloromethylation procedure and fabrication of PSF-TMA + Clused in our lab is given in our previously published work. 2 Note: higher molecular weight PSF (~75,000), Acros Organics, was used rather than the lower molecular weight PSF (~35,000) documented in our previous work. 2 The PSF-TMA + Clfilm was then ion-exchanged to sulfate form by immersing in 1 M Na 2 SO 4 solution at room temperature during 24 hours. The 1 M Na 2 SO 4 solution was changed several times over a 24 hour period to improve the ion exchange process. The PSF-TMA + in the sulfate form was immersed and rinsed with DI water for several hours (at least 3 hours) to remove excess ions. Ionic conductivity. Electrochemical impedance spectroscopy (EIS) was used to determine the in-plane conductivity of the membrane. A membrane (in sulfate form) was placed in the conductivity cell (Teflon ® cell) in contact with 4 platinum wires. The external wires were connected to the working and counter electrodes of the potentiostat and the inner electrodes were used as working sense and reference.
Surface Modification of Sulfonated Poly(phenylene oxide) Membrane for Vanadium Redox Flow Batteries
Journal of Nanoscience and Nanotechnology, 2020
Sulfonated poly(phenylene) oxide (sPPO) polymer is coated in a dopamine hydrochloride solution to prepare a highly durable, low-price polymer membrane for vanadium redox flow batteries (VRFBs). The polydopamine (PDA) coating on the sPPO membrane is confirmed using SEM and EDX analysis. sPPO coated with PDA exhibits decreased proton conductivity due to high resistance. However, VO+2 reducibility tests shows that the chemical stability is improved due to the introduction of the PDA coating layer on the sPPO membrane, which has a chemical structure with poor durability in VO+2 solution under the operating conditions of a VRFB. These results show that this polymer electrolyte membrane based on PDA-coated sPPO is a candidate for application in the long-term operation of VRFBs.