Toward alkaline-stable anion exchange membranes in fuel cells: cycloaliphatic quaternary ammonium-based anion conductors

Xue, Jiandang; Zhang, Xiangwen; Liu, Xin; Huang, T. C.; Jiang, Hongmei; Yin, Yan; Guiver, Michael D.

doi:10.1007/s41918-021-00105-7

Cited by 81 publications

(94 citation statements)

References 307 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In recent years, several new quaternary ammonium salts have been proposed to address this challenge, [92] but while they perform well in ex-situ chemical studies, their performance is very limited under normal operating conditions in electrolyzer cells. Two quaternary ammonium (QA) salts were reported to be reasonably stable in alkaline media: trimethylbenzylammonium (TMBA) and 6-azonia-spiro [5,5]undecane (ASU), both of which have been shown to react with hydroxide ions in reasonable times.…”

Section: Anion-exchange Membranesmentioning

confidence: 99%

What is Next in Anion‐Exchange Membrane Water Electrolyzers? Bottlenecks, Benefits, and Future

et al. 2022

View full text Add to dashboard Cite

As highlighted by the recent roadmaps from the European Union and the United States, water electrolysis is the most valuable high‐intensity technology for producing green hydrogen. Currently, two commercial low‐temperature water electrolyzer technologies exist: alkaline water electrolyzer (A‐WE) and proton‐exchange membrane water electrolyzer (PEM‐WE). However, both have major drawbacks. A‐WE shows low productivity and efficiency, while PEM‐WE uses a significant amount of critical raw materials. Lately, the use of anion‐exchange membrane water electrolyzers (AEM‐WE) has been proposed to overcome the limitations of the current commercial systems. AEM‐WE could become the cornerstone to achieve an intense, safe, and resilient green hydrogen production to fulfill the hydrogen targets to achieve the 2050 decarbonization goals. Here, the status of AEM‐WE development is discussed, with a focus on the most critical aspects for research and highlighting the potential routes for overcoming the remaining issues. The Review closes with the future perspective on the AEM‐WE research indicating the targets to be achieved.

show abstract

Section: Anion-exchange Membranesmentioning

confidence: 99%

What is Next in Anion‐Exchange Membrane Water Electrolyzers? Bottlenecks, Benefits, and Future

et al. 2022

View full text Add to dashboard Cite

show abstract

“…The more recently emerging anion exchange membrane fuel cells (AEMFCs) present a number of distinct advantages in relation to PEMFCs, which may favor a broad applicability. The basic conditions in the AEMFC are less corrosive and potentially allow the use of less expensive cell components, including nonfluorinated membranes, low alloy bipolar plates, and non-precious-metal catalysts, as well as a more flexible choice of fuels. − However, the presence of the basic and highly nucleophilic hydroxide ion in the anion exchange membranes (AEMs) presents a serious challenge on the chemical stability of the polymer backbones and, in particular, the cationic moieties of the AEMs.…”

Section: Introductionmentioning

confidence: 99%

“…The rationale for the high stability is the low ring strain of the six-membered rings in combination with a high activation energy of the transition states in the Hofmann β-elimination and substitution reactions induced by hydroxide attack . Inspired by this influential work, many different AEMs based on DMP and ASU cations have been prepared and studied by us ,, and other research groups. ,, The results have shown high alkaline stability in both ex situ experiments − and fuel cell evaluations. − For example, we , and others ,,, have prepared and investigated poly(arylene piperidinium) by polyhydroxylalkylations involving piperidone, which provides an ether-free polymer incorporating DMP cations in the backbone after methylation of the piperidine rings. Alternatively, cyclo-quaternization with 1,5-dibromopentane results in spirocyclic ASU cations. , …”

Section: Introductionmentioning

confidence: 99%

Poly(arylene piperidine) Anion Exchange Membranes with Tunable N-Alicyclic Quaternary Ammonium Side Chains

Pan

Pham

Jannasch

2021

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

To develop anion exchange membranes (AEMs) that combine high chemical stability and hydroxide conductivity, we have designed and prepared poly(arylene piperidine)s carrying tunable mono- or dicationic side chains. Poly(biphenyl piperidine) and poly(biphenyl N-methylpiperidine), respectively, were first synthesized by superacid-catalyzed polyhydroxylalkylations. Subsequently, the piperidine rings of these polymers were reacted with bromoalkylated N,N-dimethylpiperidinium (DMP) and 6-azonia-spiro[5.5]undecane (ASU) cations, respectively. This gave two series of AEMs in which the polymer backbone contained tertiary and quaternary piperidine rings, respectively, resulting in mono- and dicationic side chains in series 1 and 2, respectively. In series 1, both the piperidine rings in the backbone and the pendant cations in the side chains showed excellent alkaline stability, resulting in AEMs, which retained more than 92% of the cations after storage in 2 M NaOH at 90 °C during 30 days. In addition, these AEMs reached a hydroxide conductivity up to 131 mS cm–1 at 80 °C. Benefiting from a high local ionic concentration through the dicationic configuration, the AEMs in series 2 reached a higher conductivity, almost 170 mS cm–1 at 80 °C at moderate water uptake and swelling. Still, these AEMs were more vulnerable to hydroxide attack than the ones in series 1 because of the quaternary piperidinium groups placed in the polymer backbone. In conclusion, the AEMs in series 1 can be employed in electrochemical devices that operate under harsh alkaline conditions, while those in series 2 should be preserved for less aggressive alkaline conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

“…[35] This has spurred the recent, intense effort into the development of AEIs and AEMs both with the competitive OH − conductivities and alkaline stabilities that has led to a notable improvement in operational H 2 /O 2 AEMFC durabilities. [36][37][38][39][40][41][42][43][44] However, AEMFC durabilities that are high enough for commercial deployment is still far away compared to PEMFCs. [14,15] In this context, this critical limitation is not exclusively due to the materials making up the MEAs, but also due to a poor understanding and control over the nature of the interface between the AEM and AEI-containing catalyst layers (CLs) in the MEAs.…”

Section: Introductionmentioning

confidence: 99%

3D‐Zipped Interface: In Situ Covalent‐Locking for High Performance of Anion Exchange Membrane Fuel Cells

Liang

et al. 2021

Advanced Science

View full text Add to dashboard Cite

Polymer electrolyte membrane fuel cells can generate high power using a potentially green fuel (H 2 ) and zero emissions of greenhouse gas (CO 2 ). However, significant mass transport resistances in the interface region of the membrane electrode assemblies (MEAs), between the membrane and the catalyst layers remains a barrier to achieving MEAs with high power densities and long-term stabilities. Here, a 3D-interfacial zipping concept is presented to overcome this challenge. Vinylbenzyl-terminated bi-cationic quaternary-ammonium-based polyelectrolyte is employed as both the anionomer in the anion-exchange membrane (AEM) and catalyst layers. A quaternary-ammonium-containing covalently locked interface is formed by thermally induced inter-crosslinking of the terminal vinyl groups. Ex situ evaluation of interfacial bonding strength and in situ durability tests demonstrate that this 3D-zipped interface strategy prevents interfacial delamination without any sacrifice of fuel cell performance. A H 2 /O 2 AEMFC test demonstration shows promisingly high power densities (1.5 W cm −2 at 70 °C with 100% RH and 0.2 MPa backpressure gas feeds), which can retain performances for at least 120 h at a usefully high current density of 0.6 A cm −2 .

show abstract

Toward alkaline-stable anion exchange membranes in fuel cells: cycloaliphatic quaternary ammonium-based anion conductors

Cited by 81 publications

References 307 publications

What is Next in Anion‐Exchange Membrane Water Electrolyzers? Bottlenecks, Benefits, and Future

What is Next in Anion‐Exchange Membrane Water Electrolyzers? Bottlenecks, Benefits, and Future

Poly(arylene piperidine) Anion Exchange Membranes with Tunable N-Alicyclic Quaternary Ammonium Side Chains

3D‐Zipped Interface: In Situ Covalent‐Locking for High Performance of Anion Exchange Membrane Fuel Cells

Contact Info

Product

Resources

About