Branched, Side-Chain Grafted Polyarylpiperidine Anion Exchange Membranes for Fuel Cell Application

Bai, Lei; Ma, Lingling; Lv, Li; Zhang, Anran; Yan, Xiaoming; Zhang, Fengxiang; He, Gaohong

doi:10.1021/acsaem.1c01037

Cited by 70 publications

(38 citation statements)

References 70 publications

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“…Meanwhile, the mechanical properties of PPO-QG-x AEMs under hydrated state were investigated. As shown in Table 1 and Figure S29, PPO-QG-x AEMs exhibited the tensile strength of 12.9 to 17.8 MPa and elongation at break of 18.4% to 27.6%, which is comparable with some branch-type AEMs 13,15,16,[22][23][24][25]27,29,32,40 and crosslink-type AEMs. 41,49 Overall, these results indicate that PPO-QG-x AEMs have good thermal and mechanical stability, which is desirable for the applications in AEMFCs.…”

Section: Thermal Stability and Mechanical Propertiesmentioning

confidence: 76%

“…At 60 C, the SR of PPO-QG-12 AEM (1.95 mmol g À1 , 30%) is about 3.8 times lower than that of DQ-PPO-26-OH (2.06 mmol g À1 , 115%). Furthermore, PPO-QG-x AEMs exhibited competitive dimensional stability, compared with some branch-type AEMs, 23,24,28,[30][31][32] densitytype AEMs, 17,46 and crosslink-type AEMs [47][48][49] at similar IEC values. The good dimension stability is probably because the introduced dendrons can effectively separate the hydrophilic ionic segments from the hydrophobic polymer backbones, and thus restrict redundant water molecules from permeating into the membranes, 24 as well as provide larger free volume to inhibit excessive SR. 31 Meanwhile, the low degree of functionalization of PPO backbones (<13%) and welldeveloped microphase separated structure also the dimensional stability of PPO-QG-x AEMs.…”

Section: Ion Exchange Capacity Water Uptake and Swelling Ratiomentioning

confidence: 99%

“…But the reported conductivities are unsatisfactory. Hyperbranched structures may be an alternative to further improve the conductivity of AEMs, [27][28][29][30][31][32] however, the synthesis of hyperbranched polymers is kind of tedious and less controllable. 28,32 Furthermore, hyperbranched polymers usually exhibit poor film processability due to the weak chain entanglement.…”

Section: Introductionmentioning

confidence: 99%

“…Hyperbranched structures may be an alternative to further improve the conductivity of AEMs, [27][28][29][30][31][32] however, the synthesis of hyperbranched polymers is kind of tedious and less controllable. 28,32 Furthermore, hyperbranched polymers usually exhibit poor film processability due to the weak chain entanglement. 31 As macromolecules with regular branched structures, dendronized polymers (DPs) are a particular class of linear comb polymers with pendant dendrons.…”

Section: Introductionmentioning

confidence: 99%

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Improving the conductivity and dimensional stability of anion exchange membranes by grafting of quaternized dendrons

Wei

Jiang

et al. 2022

Journal of Polymer Science

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High conductivity is critical for the practical applications of anion exchange membranes (AEMs) in fuel cells. In this study, a new strategy for enhanced conductivity and dimensional stability of AEMs by incorporating quaternized dendrons is proposed. Thanks to the introduced quaternized dendrons, distinct nanoscale phase separation and well-connected ion conductive channels are formed in the as-prepared membranes (PPO-QG-x). As a result, PPO-QG-x AEMs achieve high hydroxide conductivities up to 65.5 mS cm À1 at 20 C and 121.5 mS cm À1 at 80 C (IEC = 1.95 mmol g À1 ), while possessing good dimensional stability. Meanwhile, PPO-QG-x AEMs show good alkaline stability with the maximum loss in conductivity of 15.1% after treated in 2 M NaOH at 80 C for 960 h. In addition, the single-cell assembled with PPO-QG-12 membrane exhibit a peak power density of 249.4 mW cm À2 at 60 C. Overall, this work provides a new insight to achieve high conductivity of AEMs.

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Section: Thermal Stability and Mechanical Propertiesmentioning

confidence: 76%

Section: Ion Exchange Capacity Water Uptake and Swelling Ratiomentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improving the conductivity and dimensional stability of anion exchange membranes by grafting of quaternized dendrons

Wei

Jiang

et al. 2022

Journal of Polymer Science

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“…Investigation of the effect of polymer topology on AEMs would also enrich the field, as this is rarely explored, and most polymers for AEMs have been simple linear or crosslinked network structures. Some recent studies have revealed that AEMs with branched polymer structures show significantly enhanced PPDs in the fuel cells, [85,114] demonstrating the effect of polymer topology on AEM performance. However, most state-of-the-art AEMs consist of simple PA or PE backbones with no functional groups except for cations, so it is difficult to modify their chemical structures.…”

Section: Ionic Conductivitymentioning

confidence: 99%

Anion Exchange Membranes for Fuel Cells: State‐of‐the‐Art and Perspectives

Chen

Tao

Bang

et al. 2022

Advanced Energy Materials

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Technological developments showed that fuel cells are effective sources of power for medium-to large-scale backup power and vehicular applications (e.g., automobiles and buses). [4] In particular, fuel-cellpowered electric vehicles have a longer driving range and shorter refueling time than rechargeable battery-powered vehicles. For example, Toyota has reported that its hybrid fuel cell vehicle can drive up to 830 km powered by 5 kg of H 2 at a pressure of less than 700 bar. [5,6] In this Perspective, we analyze progress in the development of fuel cells fabricated from polymer electrolyte membranes, which run at relatively low temperature (60-90 °C), start up fast, and are portable, and have thus drawn much attention for their potential commercial applications. [7] Proton exchange membrane fuel cells (PEMFCs) have proven successful for transportation and power generation applications, owing to their high power output, compact design, and lightweight cells. Their high performance is due to their use of Nafion, a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer with outstanding chemical stability [8] and excellent proton (H + ) conductivity. [9] PEMFCs' high power output has been demonstrated in stationary, portable, and high-demand devices, and in consumer vehicles. [10][11][12] However, PEMFC membranes and catalysts are expensive, and this has hindered the broader adoption of PEMFC technology by the market. Specifically, PEMFC stacks (i.e., combinations of multiple PEMFCs) are expensive due to their requirement for platinum-group metal (PGM) catalysts and fluorocarbon membranes, which account for 40% and 11% of a cell's cost, respectively, and translate to high vehicle prices. [13,14] As a result, manufacturers are attempting to meet market demand for cheaper PEMFCs by lowering their content of PGM catalysts (or eschewing PGM catalysts entirely) and avoiding their use of fluorocarbon membranes. As an alternative to the use of H + in ion transport, the corresponding redox reactions of hydroxide (OH − ) ions have received attention. Fuel cells with OH − -transporting membranes are termed anion exchange membrane fuel cells (AEMFCs). The working principles of AEMFCs are slightly different from those of PEMFCs, but their overall redox bases are the same. In an AEMFC, water and oxygen are fed into the cathode for reduction to OH − , which then travel through the AEM to the anode to meet the fuel, H 2 , which is oxidized to generate electricity, with water as a byproduct. [15][16][17][18] In contrast to PEMFCs, AEMFCs use cationic Fuel cell technology is a clean way of generating energy and should enable carbon neutrality. However, although traditional proton exchange membrane fuel cells (PEMFCs) have made a commercial impact, their high cost hinders their wider adoption. Fuel cells that use anion exchange membranes (AEMs) are a promising alternative to PEMFCs, as they can achieve the same performance at a lower cost. In this Perspective, recent trends in the fabrication of polymer-based high-performance AEM...

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Poly(aryl piperidinium)‐Based AEMs Utilizing Spirobifluorene as a Branching Agent

Ryoo,

Shin,

Song

et al. 2024

Adv Funct Materials

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The high‐performance anion exchange membranes (AEMs) are developed by incorporating 9,9′‐spirobifluorene as a 3D branching agent, addressing the common trade‐off between ion conductivity and dimensional/mechanical stability. By fine‐tuning the ratio of terphenyl to biphenyl and the amount of the branching agent, the AEM is refined, achieving high conductivity (≈190 mS cm−1 at 80 °C in 1 m KOH) with decent dimensional/mechanical properties, comparable to the recently reported state‐of‐the‐art membranes. Investigations using gas pycnometer and atomic force microscopy demonstrated that spirobifluorene enhances the fractional free volume around the membrane's backbone and more precisely modulates the separation between hydrophobic and hydrophilic domains, thus boosting both ion conductivity and mechanical stability. This membrane also displayed excellent chemical stability, with negligible degradation at 80 °C in 1 m KOH over 1,000 h. With such a membrane, an excellent cell performance is achieved, with a current density of 11.2 A cm−2 at 80 °C and 2 V in 1 m KOH, and 1.8 A cm−2 at 80 °C and 2 V in pure water conditions. The in situ membrane stability test, conducted at a constant current density of 1 A cm−2 for 500 h, showed no significant degradation.

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Branched, Side-Chain Grafted Polyarylpiperidine Anion Exchange Membranes for Fuel Cell Application

Cited by 70 publications

References 70 publications

Improving the conductivity and dimensional stability of anion exchange membranes by grafting of quaternized dendrons

Improving the conductivity and dimensional stability of anion exchange membranes by grafting of quaternized dendrons

Anion Exchange Membranes for Fuel Cells: State‐of‐the‐Art and Perspectives

Poly(aryl piperidinium)‐Based AEMs Utilizing Spirobifluorene as a Branching Agent

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