| 1. |
- Khataee, Amirreza, et al.
(författare)
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Anion exchange membrane water electrolysis using Aemion membranes and nickel electrodes
- 2022
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Ingår i: Journal of Materials Chemistry A. - 2050-7488. ; 10:30, s. 16061-16070
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Tidskriftsartikel (refereegranskat)abstract
- Anion exchange membrane water electrolysis (AEMWE) is a potentially low-cost and sustainable technology for hydrogen production that combines the advantages of proton exchange membrane water electrolysis and traditional alkaline water electrolysis systems. Despite considerable research efforts in recent years, the medium-term (100 h) stability of AemionTM membranes needs further investigation. This work explores the chemical and electrochemical durability (>100 h) of AemionTM anion exchange membranes in a flow cell using nickel felt as electrode material on the anode and cathode sides. Remixing the electrolytes between the AEMWE galvanostatic tests was very important to enhance electrolytes refreshment and the voltage stability of the system. The membranes were analyzed by NMR spectroscopy after the AEMWE tests, and the results showed no sign of severe chemical degradation. In a separate experiment, the chemical stability and mechanical integrity of the membranes were studied by soaking them in a strongly alkaline electrolyte for a month (>700 h) at 90 °C, followed by NMR analysis. A certain extent of ionic loss was observed due to chemical degradation and the membranes disintegrated into small pieces.
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| 2. |
- khataee, Amirreza, et al.
(författare)
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Anion exchange membrane water electrolysis using Aemion™ membranes and nickel electrodes
- 2022
-
Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 10:30, s. 16061-16070
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Tidskriftsartikel (refereegranskat)abstract
- Anion exchange membrane water electrolysis (AEMWE) is a potentially low-cost and sustainable technology for hydrogen production that combines the advantages of proton exchange membrane and traditional alkaline water electrolysis systems.
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| 3. |
- Salmeron-Sanchez, Ivan, et al.
(författare)
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Zwitterionic poly(terphenylene piperidinium) membranes for vanadium redox flow batteries
- 2023
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 474
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Tidskriftsartikel (refereegranskat)abstract
- Over recent years, non-fluorinated ion exchange membranes based on poly(terphenylene) backbones carrying different functional groups have shown potential application for vanadium redox flow batteries (VRFBs). Generally, the ion exchange membrane in VRFBs is a critical component in terms of the output power, long-term stability and cost. Yet, the shortcomings of commercial membranes (e.g., Nafion) have become a substantial barrier to further commercializing VRFBs. After successfully fabricating and testing poly(terphenylene)-based membranes carrying piperidinium and sulfonic acid groups, respectively, for VRFBs, we have in the present work combined both these ionic groups in a single zwitterionic membrane. A series of poly(terphenylene)-based membranes containing zwitterionic (sulfoalkylated piperidinium) and cationic (piperidinium) groups in different ratios (40–60%) were synthesized and investigated. The VRFB using the zwitterionic membranes showed competitive performance compared to Nafion 212 regarding ionic conductivity, capacity retention, and chemical stability. In addition, it was shown that the VRFB performance was improved by increasing the content of zwitterionic groups within the membrane. A self-discharge time of more than 800 h and 78.7% average capacity retention for 500 VRFB cycles were achieved using a membrane with an optimized ratio (60% zwitterionic and 40% piperidinium groups). Furthermore, the chemical stability was promising, as there was no change in the chemical structure after 500 cycles. Our results represent a critical step for developing novel and competitive ion exchange membranes as an excellent alternative to the Nafion benchmark.
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| 4. |
- Shirole, Anuja, et al.
(författare)
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Hydroxide Ion Conducting Membranes Dually Functionalized with Cationic and Zwitterionic Groups
- 2023
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Ingår i: ACS Applied Energy Materials. - 2574-0962. ; 6:13, s. 7240-7249
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Tidskriftsartikel (refereegranskat)abstract
- A series of ether-free poly(p-terphenyl piperidinium)s carrying both cationic and zwitterionic groups were prepared and evaluated as anion-exchange membranes (AEMs). First, a zwitterionic monomer (zwPip) was synthesized by sulfoalkylation of N-methyl-4-piperidone (Pip) using 1,4-butane sultone. Pip and zwPip were then employed in superacid-mediated polyhydroxyalkylations with p-terphenyl to prepare precursor copolymers containing 20, 30, and 40 mol % of zwPip units. Next, the Pip units were fully quaternized in a Menshutkin reaction with iodomethane. AEMs cast from these copolymers with ion-exchange capacities between 1.8 and 2.2 m equiv g–1 displayed excellent hydroxide ion conductivities, reaching up to 171 mS cm–1 at 80 °C. At lower temperatures, 20 and 40 °C, the water uptake decreased with increasing zwitterionic content, most probably because of the increased ionic cross-linking through piperidinium–sulfonate complexes. AEMs containing 30 and 40% zwPip units showed only a minor ionic loss (<10%) when stored in 1 M aq NaOH solution at 80 °C over a period of 720 h. The overall results show that the co-introduction of zwitterionic and cationic groups is an efficient strategy to initiate ionic cross-linking and improve the performance of hydroxide-conducting AEMs.
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| 5. |
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