Pristine and modified porous membranes for zinc slurry–air flow battery

The membrane is a crucial component of Zn slurry–air flow battery since it provides ionic conductivity between the electrodes while avoiding the mixing of the two compartments. Herein, six commercial membranes (Cellophane™ 350PØØ, Zirfon®, Fumatech® PBI, Celgard® 3501, 3401 and 5550) were first characterized in terms of electrolyte uptake, ion conductivity and zincate ion crossover, and tested in Zn slurry–air flow battery. The peak power density of the battery employing the membranes was found to depend on the in-situ cell resistance. Among them, the cell using Celgard® 3501 membrane, with in-situ area resistance of 2 Ω cm$^{2}$ at room temperature displayed the highest peak power density (90 mW cm−2). However, due to the porous nature of most of these membranes, a significant crossover of zincate ions was observed. To address this issue, an ion-selective ionomer containing modified poly(phenylene oxide) (PPO) and N-spirocyclic quaternary ammonium monomer was coated on a Celgard® 3501 membrane and crosslinked via UV irradiation (PPO-3.45 + 3501). Moreover, commercial FAA-3 solutions (FAA, Fumatech) were coated for comparison purpose. The successful impregnation of the membrane with the anion-exchange polymers was confirmed by SEM, FTIR and Hg porosimetry. The PPO-3.45 + 3501 membrane exhibited 18 times lower zincate ions crossover compared to that of the pristine membrane (5.2 × 10$^{-13}$ vs. 9.2 × 10$^{-12}$ m$^{2}$ s$^{-1}$). With low zincate ions crossover and a peak power density of 66 mW cm$^{-2}$, the prepared membrane is a suitable candidate for rechargeable Zn slurry–air flow batteries

Development of anion exchange membranes for aqueous organic redox and zinc slurry-air flow batteries

Les batteries à flux redox, en particulier, les batteries à flux redox aqueux organiques (AORFB) et les batteries Zn-air sont considérées comme des candidats très intéressants pour le stockage d'électricité à grande échelle en raison de leur sécurité élevée, de leur impact environnemental faible, de leur faisabilitééconomique et de leur forte capacité de stockage. Dans ces batteries, la membrane permet le transport des ions entre l’anolyte et le catholyte tout en assurant une barrière physique entre les deux compartiments afin d'éviter les courts-circuits électriques. Les performances, la durée de vie et le coûtde ces batteries sont fortement affectés par les propriétés physico-chimiques des membranes employées. Cependant, l’étude de l’état de l’art montre que la recherche et le développement de membranes spécifiques pour ces batteries ne sont encore pas assez importants.Dans ce manuscrit, visant à mettre en évidence les corrélations entre les propriétés des membranes et les performances en systèmes, des membranes denses échangeuses d'anions et des membranes poreuses commerciales modifiées par un ionomère ont été préparées, caractérisées et testées dans les batteries AORFB et Zn-air. Cette étude a été menée sur différentes familles de membranes, obtenues par diversesstratégies de synthèse ou de modifications de membranes poreuses, afin d’obtenir des membranes à forte conductivité et faiblement perméables aux espèces actives et ainsi améliorer les performances en batterie. Les résultats de ces travaux contribuent non seulement à avancer dans la compréhension de la relation entre les propriétés de la membrane et les performances des RFB, mais également audéveloppement futur des RFB à faible coût et hautes performances.Redox flow batteries, in particular, aqueous organic redox flow batteries (AORFBs) and Zinc (Zn) slurry-air flow batteries are considered to be very attractive candidates for large-scale electricity storage due to their safety and environmental friendliness, economic feasibility and high storage capacity. Inthese batteries, the membrane allows the transport of ions between the catholyte and the anolyte while providing a physical barrier between the two compartments in order to prevent electrical short circuits. The performance, lifespan and cost of these batteries are greatly affected by the physicochemical properties and type of the employed membrane. However, a critical discussion of the state-of-the-artstudies on membranes showed that the research and development of appropriate membranes for these batteries has received insufficient attention. In this PhD thesis, aiming at first understanding the correlations between the membranes properties and cell performances, commercial porous and prepared anion exchange membranes were ex-situ characterized and tested in the Zn slurry-air flow battery and AORFB, respectively. This was followed by various membrane synthesis and modification strategies to prepare membranes with reduced activespecies crossover and improved battery performances. The results in this work not only contribute to the basic understanding of the relationship between membrane properties and RFBs performances but also greatly contribute to the future market of the RFBs with low cost and high performance

Prospects for Anion-Exchange Membranes in Alkali Metal–Air Batteries

Rechargeable alkali metal–air batteries have enormous potential in energy storage applications due to their high energy densities, low cost, and environmental friendliness. Membrane separators determine the performance and economic viability of these batteries. Usually, porous membrane separators taken from lithium-based batteries are used. Moreover, composite and cation-exchange membranes have been tested. However, crossover of unwanted species (such as zincate ions in zinc–air flow batteries) and/or low hydroxide ions conductivity are major issues to be overcome. On the other hand, state-of-art anion-exchange membranes (AEMs) have been applied to meet the current challenges with regard to rechargeable zinc–air batteries, which have received the most attention among alkali metal–air batteries. The recent advances and remaining challenges of AEMs for these batteries are critically discussed in this review. Correlation between the properties of the AEMs and performance and cyclability of the batteries is discussed. Finally, strategies for overcoming the remaining challenges and future outlooks on the topic are briefly provided. We believe this paper will play a significant role in promoting R&D on developing suitable AEMs with potential applications in alkali metal–air flow batteries

Membranes échangeuses d’anions pour technologies de batteries à flux : batterie redox-organique et zinc-air

Redox flow batteries, in particular, aqueous organic redox flow batteries (AORFBs) and Zinc (Zn) slurry-air flow batteries are considered to be very attractive candidates for large-scale electricity storage due to their safety and environmental friendliness, economic feasibility and high storage capacity. Inthese batteries, the membrane allows the transport of ions between the catholyte and the anolyte while providing a physical barrier between the two compartments in order to prevent electrical short circuits. The performance, lifespan and cost of these batteries are greatly affected by the physicochemical properties and type of the employed membrane. However, a critical discussion of the state-of-the-artstudies on membranes showed that the research and development of appropriate membranes for these batteries has received insufficient attention. In this PhD thesis, aiming at first understanding the correlations between the membranes properties and cell performances, commercial porous and prepared anion exchange membranes were ex-situ characterized and tested in the Zn slurry-air flow battery and AORFB, respectively. This was followed by various membrane synthesis and modification strategies to prepare membranes with reduced activespecies crossover and improved battery performances. The results in this work not only contribute to the basic understanding of the relationship between membrane properties and RFBs performances but also greatly contribute to the future market of the RFBs with low cost and high performance.Les batteries à flux redox, en particulier, les batteries à flux redox aqueux organiques (AORFB) et les batteries Zn-air sont considérées comme des candidats très intéressants pour le stockage d'électricité à grande échelle en raison de leur sécurité élevée, de leur impact environnemental faible, de leur faisabilitééconomique et de leur forte capacité de stockage. Dans ces batteries, la membrane permet le transport des ions entre l’anolyte et le catholyte tout en assurant une barrière physique entre les deux compartiments afin d'éviter les courts-circuits électriques. Les performances, la durée de vie et le coûtde ces batteries sont fortement affectés par les propriétés physico-chimiques des membranes employées. Cependant, l’étude de l’état de l’art montre que la recherche et le développement de membranes spécifiques pour ces batteries ne sont encore pas assez importants.Dans ce manuscrit, visant à mettre en évidence les corrélations entre les propriétés des membranes et les performances en systèmes, des membranes denses échangeuses d'anions et des membranes poreuses commerciales modifiées par un ionomère ont été préparées, caractérisées et testées dans les batteries AORFB et Zn-air. Cette étude a été menée sur différentes familles de membranes, obtenues par diversesstratégies de synthèse ou de modifications de membranes poreuses, afin d’obtenir des membranes à forte conductivité et faiblement perméables aux espèces actives et ainsi améliorer les performances en batterie. Les résultats de ces travaux contribuent non seulement à avancer dans la compréhension de la relation entre les propriétés de la membrane et les performances des RFB, mais également audéveloppement futur des RFB à faible coût et hautes performances

Prospects for Anion-Exchange Membranes in Alkali Metal–Air Batteries

International audienceRechargeable alkali metal–air batteries have enormous potential in energy storage applications due to their high energy densities, low cost, and environmental friendliness. Membrane separators determine the performance and economic viability of these batteries. Usually, porous membrane separators taken from lithium-based batteries are used. Moreover, composite and cation-exchange membranes have been tested. However, crossover of unwanted species (such as zincate ions in zinc–air flow batteries) and/or low hydroxide ions conductivity are major issues to be overcome. On the other hand, state-of-art anion-exchange membranes (AEMs) have been applied to meet the current challenges with regard to rechargeable zinc–air batteries, which have received the most attention among alkali metal–air batteries. The recent advances and remaining challenges of AEMs for these batteries are critically discussed in this review. Correlation between the properties of the AEMs and performance and cyclability of the batteries is discussed. Finally, strategies for overcoming the remaining challenges and future outlooks on the topic are briefly provided. We believe this paper will play a significant role in promoting R&D on developing suitable AEMs with potential applications in alkali metal–air flow batteries

Stability of polyethersulfone membranes to oxidative agents: A review

© 2018 Elsevier Ltd Polyethersulfone (PES) is one of the most commonly used polymers for preparation of ultrafiltration and nanofiltration membranes. However, oxidative degradation of PES-based membranes, which results from exposing the membranes to oxidative agents, is limiting their operational lifespan and possible areas of application. Despite the high need for a fundamental understanding of the detailed oxidative degradation mechanism(s) of PES membranes in order to improve the effectiveness of cleaning/disinfecting agents and/or develop PES membranes with a higher tolerance to oxidative agents, it still remains an insufficiently understood topic. Therefore, this review aims at analyzing and critically discussing the recent state-of-the-art on the degradation mechanisms of PES membranes, focusing on the effects of chlorine-based oxidants (mainly NaOCl) and H2O2. Strategies that can be useful for minimizing/preventing oxidative PES membranes attack are presented. Finally, further prospective study possibilities to fill in the existing research gaps in this area are highlighted.status: publishe

Anion Exchange Membranes for High Performance Neutral Aqueous Organic Redox Flow Battery

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High-Performance Anion Exchange Membrane for Aqueous Organic Redox Flow Battery

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Design of Monovalent Ion Selective Membranes for Reducing the Impacts of Multivalent Ions in Reverse Electrodialysis

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