Hydroxide Conductivity Research Articles

Novel polyaryl isatin polyelectrolytes with flexible monomers for anion exchange membrane fuel cells

The stability of the anion exchange polyelectrolytes is closely tied to the durability of anion exchange membrane fuel cells. Given their excellent alkali resistance, ether-free polymer backbones have attracted considerable attention for use in anion-exchange polyelectrolytes. Herein, a series of side-chain-type poly(terphenylene-co-dibenzyl N-(6-bromohexyl)-isatin) copolymers (QAPTDBHI-n) were synthesized via superacid-catalyzed polymerization and a subsequent quaternization reaction. The cyclic cardo groups in the backbones enabled the formation of nanovoids, which facilitated ionic clusters’ self-aggregation. The introduction of flexible bibenzyl monomers provided the polymers with a spatially foldable structure, promoting the aggregation of ion clusters and strengthening interchain interactions. Compared with the membrane without flexible monomers, QAPTDBHI-n membranes exhibited higher hydroxide conductivity (>115 mS cm−1 at 80 °C), outstanding mechanical stability (tensile strength: 50.91–60.76 MPa, elongation at break: 14.27%–26.06%), and superior alkali resistance (1 M NaOH at 80°C for >1500 h and <9.5% OH− conductivity loss). Regarding fuel cell performance, the AEMFC based on QAPTDBHI-40 ionomer achieved a peak power density of 1.14 W cm−2 (H2–O2) and 0.86 W cm−2 (H2-Air, CO2 free) at 80 °C due to its higher water uptake, OH− conductivity, and lower phenyl concentration.

How can we design anion-exchange membranes to achieve longer fuel cell lifetime?

The substantial advancements and availability of new cost-effective materials have drawn significant attention to the anion-exchange membrane fuel cell (AEMFC) technology. The anion exchange membrane (AEM) is a core component in AEMFCs, essential for conducting hydroxide ions and controlling water transport between the fuel cell electrodes. In this study, we apply a numerical model to investigate the relationship and sensitivity of AEMFC performance and its stability to key AEM properties. Our findings show that membrane maximum hydration level (λmax) has the most significant impact on AEMFC lifetime, followed by membrane ion-exchange capacity, water diffusivity, and membrane thickness. We also demonstrate the significance of improving the stability of the functional group to AEMFC lifetime, while AEM hydroxide conductivity shows a negligible effect on AEMFC lifetime. Finally, we provide a simple algebraic functional relationship between key dimensionless parameters as well as a machine learning-based analysis of the relationship between AEM parameters and AEMFC lifetime. Through these analyses, we calculate the lifetime of selected membranes from the literature and compare them to the measured operation time. This study summarizes and highlights important AEM property targets suggested to improve AEM design to boost the performance stability of AEMFCs.

Fabrication of dense anion exchange membranes by filling polymer matrix into quaternized branched polyethyleneimine @cellulose aerogel through in-situ polymerization

In order to construct interconnected three-dimensional ion transport structures within anion exchange membranes (AEMs), we proposed the idea of preparing AEMs by filling the aerogel three-dimensional network skeleton by in-situ polymerization. First, quaternized branched polyethyleneimine (QBPEI) with a large number of quaternary ammonium groups was cross-linked with cellulose to construct an aerogel with a three-dimensional network. Then, poly(4-vinylbenzyl chloride) (PVBC) was filled into the aerogel network through in-situ polymerization. Finally, dense AEMs with internal three-dimensional ion transport networks were prepared by hot pressing PVBC/QBPEI@cellulose. The prepared AEMs have low ion exchange capacity (IEC) values and high ionic conductivities, with the membrane with the best overall performance (IEC value of 1.58 meq./g) having a maximum hydroxide conductivity of 38.88 mS/cm at 80 °C. In addition, the optimized membrane has good chemical and dimensional stability, and the maximum power density of the fuel cell assembled based on it is 46.32 mW/cm2. Although the performance of the prepared composite membranes needs to be further improved due to the preparation process, the design idea in this work provides a feasible solution for the construction of continuous ion fast transport channels in AEMs.

Dual reinforced composite membranes from in-situ ionic crosslinked quaternized chitosan filled quaternized polyvinylidene fluoride nanofiber for alkaline direct methanol fuel cell

The main obstacle of high-performance cationic functionalization chitosan (CS) as anion exchange membranes (AEMs) is the trade-off between mechanical stability and ionic conductivity. Here, in-situ ionic crosslinking between the deprotonated hydroxyl group and quaternary ammonium group under alkaline conditions was ingeniously applied to improve the mechanical stability of highly quaternized CS (HQCS) with high IEC (>2 mmol g−1). Meanwhile, to further reduce the swelling and enhance the hydroxide conductivity, a mechanically robust hydroxide ion conduction network, quaternized electrospun poly(vinylidene fluoride) (QPVDF) nanofiber, was subsequently used as the filling substrate of in-situ crosslinked HQCS to prepare dual reinforced thin AEMs. The introduction of a robust QPVDF nanofiber mat can not only greatly improve the mechanical properties and limit swelling, but also create facile ion transport channels. Notably, the HQCS/QPVDF-74.0 composite membrane demonstrates perfect dimensional stability, high mechanical performance and excellent alkaline stability, as well as superior ionic conductivity of 66.2 mS cm−1 at 80 °C. The thus assembled alkaline direct methanol fuel cell displays a maximum power density of 132.30 mW cm−2 using 5 M KOH and 3 M methanol as fuels at 80 °C with satisfactory durability.

Model of Hydrogen Production by Combination of Water Electrolysis and Unstable Sources of Energy

Water electrolysis is accepted as direct method for hydrogen production from water. The emission pathway of hydrogen is related to the source of electric energy and process of water electrolysis just define energy efficiency or amount of hydrogen produced from energy supplied. For green hydrogen production almost exclusively, renewable energy sources are necessary. But unstable production is typical for most frequently mentioned wind and solar power station. Currently four types of water electrolyzers are available: Proton exchange membrane water electrolysis (PEMWE), Alkaline water electrolysis (AWE), Membrane alkaline water electrolysis (MAWE) and high temperature solid oxide water electrolysis (SOWE). Each of mentioned type exhibits different properties and requirements if operated in combination with renewable power sources. Proper selection of electrolyzer type and its size is crucial for economic production of hydrogen.PEMWE shows higher flexibility in operation changes. Its warming up to operating temperature is only few minutes or seconds due to the high current densities, thin ion conductive membrane and circulation only of demineralized water. Its production range is limited by hydrogen permeation through membrane at low production and electrolyzer stability at high production. The production range starts usually from 5% and finish at short term 120% of designed capacity.AWE represents oldest technology with high durability proved by large number of installations. But old electrolysers were designed for continual operation with limited possibility to moderate its production. Newly developed units are better adapted to intermittent operation. Parasitic currents in electrolyte distribution channels are main reason for efficiency decrease at low loading. Their minimum operation range varies from 1% up to 30% depending of manufacturer and size. Despite it, the request for circulation of concentrated hydroxide and low conductivity of separator make warm up period significantly slower with low efficiency. Therefore, frequent phase off and on affect the total amount of produced hydrogen.MAWE is newest electrolyzer type. It combines the concept of ion selective membrane usage as separator and alkaline environment to avoid platinum metals need. Thanks to the ion-selective membrane the startup dynamics is faster but durability of membrane limits its operation temperature.SOWE as process with operating temperature 800 °C is not suitable for irregular operation. But it high efficiency make this process interesting for combination of power sources to keep permanent run. Nuclear and renewable power sources are one of possible combination.Mathematical model capable to calculate actual and integral production of hydrogen on the base of known power sources production and elektrolyzer parameters was created. Input data of elektrolyzer behavior for the model come from an in-house measurement and from literature. Various data of for unstable power sources involve a photovoltaic power-plant and train recuperation energy from braking on the 15 min interval were taken.Created model indicates production capacity of given combination and also the running time and amount of utilized energy. With consideration of investment cost i tis able to estimate most suitable sizes.Acknowledgment:This project is financed by the Technology Agency of the Czech Republic under grant TO01000324, in the frame of the KAPPA programme, with funding from EEA Grants and Norway Grants.

Poly(Ethylene Piperidinium)s for Anion Exchange Membranes.

The lack of anion exchange membranes (AEMs) that possess both high hydroxide conductivity and stable mechanical and chemical properties poses a major challenge to the development of high-performance fuel cells. Improving one side of the balance between conductivity and stability usually means sacrificing the other. Herein, we used facile, high-yield chemical reactions to design and synthesize a piperidinium polymer with a polyethylene backbone for AEM fuel cell applications. To improve the performance, we introduced ionic crosslinking into high-cationic-ratio AEMs to suppress high water uptake and swelling while further improving the hydroxide conductivity. Remarkably, PEP80-20PS achieved a hydroxide conductivity of 354.3 mS cm-1 at 80 °C while remaining mechanically stable. Compared with the base polymer PEP80, the water uptake of PEP80-20PS decreased by 69 % from 813 % to 350 %, and the swelling decreased substantially by 85 % from 350.0 % to 50.2 % at 80 °C. PEP80-20PS also showed excellent alkaline stability, 84.7 % remained after 35 days of treatment with an aqueous KOH solution. The chemical design in this study represents a significant advancement toward the development of simultaneously highly stable and conductive AEMs for fuel cell applications.

Poly(Ethylene Piperidinium)s for Anion Exchange Membranes

AbstractThe lack of anion exchange membranes (AEMs) that possess both high hydroxide conductivity and stable mechanical and chemical properties poses a major challenge to the development of high‐performance fuel cells. Improving one side of the balance between conductivity and stability usually means sacrificing the other. Herein, we used facile, high‐yield chemical reactions to design and synthesize a piperidinium polymer with a polyethylene backbone for AEM fuel cell applications. To improve the performance, we introduced ionic crosslinking into high‐cationic‐ratio AEMs to suppress high water uptake and swelling while further improving the hydroxide conductivity. Remarkably, PEP80‐20PS achieved a hydroxide conductivity of 354.3 mS cm−1 at 80 °C while remaining mechanically stable. Compared with the base polymer PEP80, the water uptake of PEP80‐20PS decreased by 69 % from 813 % to 350 %, and the swelling decreased substantially by 85 % from 350.0 % to 50.2 % at 80 °C. PEP80‐20PS also showed excellent alkaline stability, 84.7 % remained after 35 days of treatment with an aqueous KOH solution. The chemical design in this study represents a significant advancement toward the development of simultaneously highly stable and conductive AEMs for fuel cell applications.

Synergistic interaction and alkali resistance of N-spirocyclic cations with piperidine cations for poly(biphenyl piperidine) membranes

The conformation of N-spirocyclic cations has a high alkaline stability and the construction of microphase-separated structures with poly(biphenyl piperidine) (PBP) is one way to improve the performance of AEM. Here, a variety of N-spirocyclic cations were prepared and formed into polycationic side chains with the PBP main chain via the -(CH2)4- spacer group. The ion transport efficiency was greatly enhanced by the synergistic effect of the main chain piperidine cations, and the hydroxide conductivity and peak power density of the MDSU-MPBP membrane reached 132.7 mS cm-1 and 295.2 mW cm-2 at 80 °C, respectively. The BM-DSU cation was degraded to a single cation mainly by the SN2 reaction after 96 h in a 5 M NaOH/D2O solution at 80 °C. The N-spirocyclic mono-cation has extremely high alkali resistance, especially the MDSU cation without significant degradation at 80 °C for 1008 h. The B-MDSU double cation tends to undergo the SN2 reaction at the C2 and C4 positions. The asymmetrically grafted main-chain piperidine cations exhibit poor chemical stability due to the electron-absorbing effect of the phenyl group. the degradation of the MDSU cations increases the hydrophobicity of the side chains, and the MDSU-MPBP membrane has the best alkali resistance, with a conductivity residual of more than 92.8% after immersion in a 5 M NaOH solution at 80 °C for 480 h.

An effective alkaline solid electrolyte with magnetic field-aligned Fe3O4–GO nanofillers in a polybenzimidazole membrane for methanol fuel cells

In this work, alkaline-doped polybenzimidazole/magnetite–graphene oxide (PBI/Fe3O4–GO) nanocomposite membranes are successfully synthesized for enhanced ion conduction and suppressed alcohol permeation for use in direct methanol alkaline fuel cells (DMAFCs). The structural, morphological, and magnetic properties of Fe3O4–GO nanofillers are thoroughly investigated. During the membrane drying step, the Fe3O4–GO nanofillers are aligned in a polymeric PBI matrix using an applied magnetic field (MF). Without an MF, the nanofillers are randomly distributed in the PBI matrix. The composite membrane with the MF demonstrates a 2- to 3-fold increase in hydroxide conductivity (7.6 × 10−2 S cm−1) and a one-order of magnitude reduction in fuel permeability (9.96×10−7 cm2 s−1) compared to the other samples. The potassium hydroxide (KOH)-doped PBI/Fe3O4–GO composite with MF achieves a higher maximum power density (Pmax) of 226 mW cm−2 at 80 °C than the other samples. The composite membrane with an MF demonstrates good long-term durability of 107 h with low voltage decay (6.5 × 10−4 V h−1) at high alkaline concentrations (6 M KOH). The results indicate that a small amount (0.5 wt%) of Fe3O4–GO nanofillers has an extensive effect on membrane properties in DMAFCs.

Semi-Interpenetrating Network Anion Exchange Membranes by Thiol-Ene Coupling Reaction for Alkaline Fuel Cells and Water Electrolyzers.

In this work, a thiol-ene coupling reaction was employed to prepare the semi-interpenetrating polymer network AEMs. The obtained QP-1/2 membrane exhibits high hydroxide conductivity (162.5 mS cm-1 at 80 °C) with a relatively lower swelling ratio, demonstrating its mechanical strength of 42 MPa. This membrane is noteworthy for its improved alkaline stability, as the semi-interpenetrating network effectively limits the attack of hydroxide. Even after being treated in 2 M NaOH at 80 °C for 600 h, 82.5% of the hydroxide conductivity is maintained. The H2/O2 fuel cell with QP-1/2 membrane displays a peak power density of 521 mW cm-2. Alkaline water electrolyzers based on QP-1/2 membrane demonstrated a current density of 1460 mA cm-2 at a cell voltage of 2.00 V using NiCoFe catalysts in the anode. All the results demonstrate that a semi-interpenetrating structure is a promising way to enhance the mechanical property, ionic conductivity, and alkaline stability of AEMs for the application of alkaline fuel cells and water electrolyzers.

High Performance Anion Exchange Membranes with Confined Sub‐2‐nm Ion Channel

AbstractAs a key component of low‐cost anion exchange membrane fuel cells (AEMFCs), anion exchange membranes (AEMs) are far from commercial application, because of dissatisfactory alkaline stability and conductivity. Herein, a new insight is proposed to prepare high performance AEMs by constructing of confined ion channel. With an intermediate oligomer produced before the main copolymerization, novel poly(vinyl‐carbazolyl aryl piperidinium) AEMs with confined sub‐2‐nm ion channel are successfully prepared. The unique sub‐2‐nm ion channel enable membranes ultrahigh hydroxide conductivity of 261.6 mS cm−1, and the state‐of‐the‐art chemical stability over 5000 h. Moreover, the AEMs also exhibit good mechanical stability with lower water uptake and dimensional swelling. Based on the as‐prepared AEMs and ionomer, fuel cells exhibit outstanding peak power density of 1.8 and 0.2 W cm−2 with Pt‐based catalysts and completely non‐precious metal catalysts, respectively.

Dithiol cross-linked polynorbornene-based anion-exchange membranes with high hydroxide conductivity and alkaline stability

Vinylic-addition polynorbornenes possess high thermal stability, excellent mechanical integrity, and chemically inert backbones. Herein, we conveniently synthesize a series of vinylic-addition polynorbornene copolymers containing pendant alkenes from commercial vinyl-substituted norbornene (VNB) and alkyl-bromide-substituted norbornene (BrNB). Subsequently, the copolymers are photo-crosslinked with dithiol reagents through UV-initiated thiol-ene click reactions followed by quaternization to prepare the cross-linked anion-exchange membranes (AEMs). The extent of cross-linking and the hydrophobicity of the cross-linkers can be easily controlled, so that the absorption of excess water can be inhibited with enhanced membrane strength. The resultant AEMs have ultrahigh hydroxide conductivities (up to 199 mS/cm at 90 °C under humidified conditions) and excellent alkaline stability in 1 M KOH at 80 °C for 1200 h. The vinylic-addition AEMs are also successfully applied in alkaline anion-exchange membrane water electrolyzers with commercial noble-metal-free electrocatalysts.

Constructing lamellar low temperature anion exchange membranes based on polymerized ionic liquid and graphene oxide nanosheets

Polymerized ionic liquid (PIL) of poly(1-vinyl-3-methylimidazolium) chloride (poly(vmim)Cl) and graphene oxide (GO) nanosheets were respectively deposited on the surface of Kevlar aramid nanofibers (KANFs) substrates to construct anion exchange membranes (AEMs). The multilayered microstructure resulted in orderly distributed components, which thus improved the mechanical properties and dimension stability of the lamellar low-temperature AEMs. The imidazolium cations in PIL and the polar oxygen functional groups in GO nanosheets constituted the interconnected hydroxide ion conduction channels in the prepared Kevlar/(PIL/GO)60 membrane. Relative to the ionic liquid (IL) monomer of 1-vinyl-3-methylimidazolium chloride, the PIL with polymerized molecular chains could be embedded in GO nanosheets with the formation of a stable microstructure. The Kevlar/(PIL/GO)60 membrane exhibited the enhanced alkaline stability relative to the Kevlar/(IL/GO)60 membrane. Furthermore, the hydroxide conduction behavior in the AEMs at subzero temperatures has been researched in consideration of the long-term exposure in colder conditions of the vehicles equipped with fuel cells. As a result, the Kevlar/(PIL/GO)60 membrane exhibited a hydroxide conductivity of 0.94 mS/cm at −25 °C, 5.25 mS/cm at 30 °C, and 64.7 mS/cm at 80 °C. Meanwhile, good alkaline stability was revealed from the ten-cycle hydroxide conductivities and long-time hydroxide conductivities. In addition, the PIL enhanced the mechanical strength of the Kevlar/(PIL/GO)60 membrane, with the tensile stress at break increasing by 31.3% compared with that of the Kevlar/(IL/GO)60 membrane.

Direct Insertion Polymerization of Ionic Monomers: Rapid Production of Anion Exchange Membranes

AbstractThe limited number of methods to directly polymerize ionic monomers currently hinders rapid diversification and production of ionic polymeric materials, namely anion exchange membranes (AEMs) which are essential components in emerging alkaline fuel cell and electrolyzer technologies. Herein, we report a direct coordination‐insertion polymerization of cationic monomers, providing the first direct synthesis of aliphatic polymers with high ion incorporations and allowing facile access to a broad range of materials. We demonstrate the utility of this method by rapidly generating a library of solution processable ionic polymers for use as AEMs. We investigate these materials to study the influence of cation identity on hydroxide conductivity and stability. We found that AEMs with piperidinium cations exhibited the highest performance, with high alkaline stability, hydroxide conductivity of 87 mS cm−1 at 80 °C, and a peak power density of 730 mW cm−2 when integrated into a fuel cell device.

Direct Insertion Polymerization of Ionic Monomers: Rapid Production of Anion Exchange Membranes.

The limited number of methods to directly polymerize ionic monomers currently hinders rapid diversification and production of ionic polymeric materials, namely anion exchange membranes (AEMs) which are essential components in emerging alkaline fuel cell and electrolyzer technologies. Herein, we report a direct coordination-insertion polymerization of cationic monomers, providing the first direct synthesis of aliphatic polymers with high ion incorporations and allowing facile access to a broad range of materials. We demonstrate the utility of this method by rapidly generating a library of solution processable ionic polymers for use as AEMs. We investigate these materials to study the influence of cation identity on hydroxide conductivity and stability. We found that AEMs with piperidinium cations exhibited the highest performance, with high alkaline stability, hydroxide conductivity of 87 mS/cm at 80 °C, and a peak power density of 730 mW/cm2 when integrated into a fuel cell device.

Highly Ion-Conductive and Alkaline Stable Anion Exchange Membranes Containing Bulky Aryl Units and Symmetric bis-Piperidinium Branches

The challenge in developing high-performance anion exchange membranes (AEMs) involves achieving high ion conductivity while maintaining sufficient alkaline and mechanical stability. In this work, an aromatic monomer [bis(4′-(1,5-dibromopentan-3-yl)phenyl)-1,4-terphenyl (BBTP)] with a bulky aryl unit and symmetric dibrominated branches was first designed and synthesized. Then, BBTP was used to prepare aryl ether-free AEMs (QPTPDP-x-OH) via the superacid-catalyzed polyhydroxyalkylation and Menshutkin reactions. Due to the several structural advantages of BBTP, QPTPDP-x-OH membranes reached high hydroxide conductivity up to 161.5 mS cm–1 at 80 °C while maintaining good dimensional stability. Moreover, the membranes exhibited high alkaline stability with the conductivity retention above 80% after soaking in 5 M NaOH at 80 °C for 1200 h. In addition, QPTPDP-30-OH membranes achieved a peak power density of 407.8 mW cm–2 in H2–O2 fuel cells at 60 °C. The design strategy used in this work provided insights into the development of next-generation AEMs with high performance.

Towards highly conducting and stable poly(fluorenyl biphenyl)-based anion exchange membranes by grafting dual Y-shaped side-chains

High hydroxide conductivity and sufficient dimensional/alkaline/mechanical stability are highly desired for practical applications of anion exchange membranes (AEMs). Herein, a new di-quaternized side-chain precursor (EDQA) was firstly designed and synthesized. Then novel AEMs (DBTF-4QA-x) based on poly(fluorenylene alkylene)s containing dual Y-shaped side-chains were prepared from EDQA by an efficient click reaction. Benefiting from several structural advantages of EDQA, DBTF-4QA-x membranes possessed high hydroxide conductivities up to 154.8 mS cm−1 at 80 °C, while maintained high dimensional stability. The membranes exhibited robust mechanical properties with tensile strengths and elongation at break up to 107.4 MPa and 46.4%, respectively. Furthermore, the membranes showed high alkaline stability with the conductivity loss below 11.4% after immersing in 4 M aq. NaOH at 80 °C for 40 days. In addition, DBTF-4QA-0.5 membrane achieved the maximum peak power density of 836.4 mW cm−2 in H2/O2 fuel cells at 60 °C.

Block poly(arylene ether nitrile ketone)s with comb-shaped alkyl chains as anion exchange membranes

A new approach is presented here for constructing higher-performance anion exchange membranes (AEMs) by combining block-type and comb-shaped architectures. A series of quaternization fluorene-containing block poly (arylene ether nitrile ketone)s (QFPENK-m-n) were synthesized by varying the length of hydrophobic segment as AEMs. The well-designed architecture, which involved grafting comb-shaped C10 long alkyl side chains onto the block-type main chains, formed efficient ion-transport channels, as confirmed by atomic force microscopy. As a result, the AEMs showed high hydroxide conductivities in the range of 34.3–102.1 mS⋅cm−1 from 30 to 80 °C at moderate ion exchange capacities (IECs). Moreover, the hydrophobic segment with nitrile groups also exhibited a profound anti-swelling property for the AEMs, resulting in ultralow swelling ratios ranging from 4.7% to 7.1% at 30 °C and 7.5%–9.8% at 80 °C, as well as superb conductivity-to-swelling ratios at 80 °C. In addition, the AEMs displayed good mechanical properties, thermal and oxidative stability, and optimizable alkaline stability.

Construction of alkali-stable anion exchange membranes with hydrophilic/hydrophobic microphase separation structure by adjusting side chain length

A series of side-chains anion exchange membranes were assembled by poly (arylene ether ketone) with amino groups (Am-PAEK) which was grafted different length of side chains by Friedel-Crafts acylation and then imidazole cationic groups were introduced by bromination reaction. The side-chain membranes exhibited excellent mechanical properties, thermal stability and alkali stability. In addition, swelling ratios of side chain membranes were lower than 10% even at 100 °C. And the alkali stability of Im-AP-6 (where Am-PAEK was grafted with 6-bromohexanoyl chloride and then grafted with 1,2-dimethylimidazole.) was higher than 87% after immersing in 1 M NaOH for 168 h at 60 °C. Hydroxide conductivities of the membranes were in the range of 43.5 ∼ 49.8 mS cm−1 at 30 °C and 87.3 ∼ 126.6 mS cm−1 at 80 °C. The open circuit voltage (OCV) and peak power density of Im-AP-6 were 1.13 V and 389.71 mW cm−2 (80 °C, 100% RH), respectively. The results showed side-chain membranes have good comprehensive properties and substantially possible as AEMs.

The design and synthesis of a long-side-chain-type anion exchange membrane with a hydrophilic spacer for alkaline fuel cells

Outstanding alkaline stability and high conductivity make side-chain-type anion exchange membranes (AEMs) become one of the ideal materials for AEM fuel cells (AEMFCs). However, the hydrophobic alkyl spacer between polymer backbones and cationic groups in AEMs limited their performance in AEMFCs. Herein, we demonstrated the design and synthesis of long-side-chain-type AEMs containing a hydrophilic ethylene oxide (EO) spacer using an appropriate EO-based monomer via click reaction. The obtained PPO-O-40 membrane with EO spacers showed higher hydroxide conductivity (52.1 mS cm−1 at 20 °C) than its counterpart with an alkyl spacer (PPO–C-40). The improved chemical stability of the PPO-O-x membrane was validated by an alkaline stability test for soaking in 1 M NaOH at 60 °C for 864 h. More importantly, an AEMFC assembled with the PPO-O-40 membrane displayed an outstanding peak power of 690 mW cm−2 at 60 °C under the optimal relative humidity of the anode. The short-term durability test observed a voltage decay rate of 6.1 mV h−1 during the continuous operation for 8 h at 200 mA cm−2. This work provides an alternative way to design highly conductive and durable side-chain-type AEMs containing a hydrophilic spacer for alkaline fuel cell application.