JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Xinli Zhang,Shoutao Gong,Long Han,Quan Jin,Xiaoming Yan,Gaohong He,Fengxiang Zhang
Polyarylpiperidinium anion exchange membranes (AEMs) have been widely studied in anion exchange membrane fuel cells and alkaline electrolyzed water due to their excellent alkali resistance stability. In this work, we report the design and fabrication of poly(p-triphenylene-piperidinyl) (PTP) AEMs quaternized and cross-linked by bromo-β-cyclodextrin (β-CD-Br 7 ). In this type of membranes, the densely cross-linked and quaternized sites derived from β-CD-Br 7 can help to construct continuous ion transport channels to facilitate ion conduction. Although the ion exchange capacity (IEC) tended to decrease with increasing cross-linking degree, the qPTP-CD 5 membrane with 5 % cross-linking (IEC = 2.3 mmol g −1 ) produced the most significant microphase separation and the highest conductivity (125.6 mS cm −1 at 80 °C). The membrane also exhibited impressive alkaline stability, with 94.6 % conductivity retention in 1 M NaOH at 80 °C after 1000 h and 90.7 % conductivity retention after 1500 h. Finally, the peak power density of the fuel cell assembled with qPTP-CD 5 membranes was 1.216 W cm −2 at 80 °C and there was no significant voltage degradation when operated at 200 mA cm −2 current density for 40 h. This work demonstrates that β-CD can function as a good “platform” for simultaneous cross-linking and quaternization to fabricate high performance AEM.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Ning Xie,Tao Wang,Haowei Kang,Yiting Liu,Xinli Li,Qiang Weng,Xingming Ning,Pei Chen,Xinbing Chen,Zhongwei An
High-performance anion exchange membranes (AEMs) have garnered increasing attention in recent years. However, commercial progress of the AEM for fuel cells is still hindered by its low ionic conductivity and inadequate alkaline stability. In this study, we propose the incorporation of a hydrophobic rigid-flexible coupled side chain into a polycarbazolyl AEM as an innovative approach to enhance both the conductivity and stability. The results demonstrate that the AEMs with hydrophobic rigid-flexible coupled side chains exhibit superior conductivity and stability compared with those without (PQMC-0). For example, the ion exchange capacity of PQMC-10 is reduced by 11% than PQMC-0, but its conductivity is enhanced by 14%, dimensional change is decreased by almost half, and oxidative stability is increased by more than four times. Improved conductivity of the AEMs can be attributed to the presence of hydrophobic rigid-flexible coupled side chains, making it easier for AEM to construct microphase separation to facilitate ion transport. Furthermore, the introduction of hydrophobic side chains reduces water absorption of the membrane, thereby enhancing its dimensional stability while minimizing the intake of free radicals or hydroxide ions present in water. Consequently, this modification significantly improves the oxidative and alkaline stability as well. Finally, the PQMC-10 shows a maximum power density of 649 mW cm–2 in a single fuel cell, which is three times bigger than that of PQMC-0, indicating a promising application in the field of fuel cells.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2024
·Vol. 10
·期 42
·
IF 11.7
Yanling Ma,Jiaheng Peng,Jiakang Tian,Wenpei Gao,Jialiang Xu,Fan Li,Peter Tieu,Hao Hu,Yi Wu,Wenlong Chen,Lei Pan,Wen Shang,Peng Tao,Chengyi Song,Hong Zhu,Xiaoqing Pan,Tao Deng,Jianbo Wu
Shape-controlled alloy nanoparticle catalysts have been shown to exhibit improved performance in the oxygen reduction reaction (ORR) in liquid half-cells. However, translating the success to catalyst layers in fuel cells faces challenges due to the more demanding operation conditions in membrane electrode assembly (MEA). Balancing durability and activity is crucial. Here, we developed a strategy that limits the atomic diffusion within surface layers, fostering the phase transition and shape retention during thermal treatment. This enables selective transformation of platinum-iron nanowire surfaces into intermetallic structures via atomic ordering at a low temperature. The catalysts exhibit enhanced MEA stability with 50% less Fe loss while maintaining high catalytic activity comparable to that in half-cells. Density functional calculations suggest that the ordered intermetallic surface stabilizes morphology against rapid corrosion and improves the ORR activity. The surface engineering through atomic ordering presents potential for practical application in fuel cells with shape-controlled Pt-based alloy catalysts.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Joule
·
2024
·
IF 38.6
Jiandang Xue,John C. Douglin,Karam Yassin,Tong Huang,Haifei Jiang,Junfeng Zhang,Yan Yin,Dario R. Dekel,Michael D. Guiver
Over the last decade, anion-exchange membrane fuel cells (AEMFCs) have continued to show steady power output and durability improvements at low temperatures of 60°C–80°C. However, AEMFC durability still lags, largely due to the critical issue of water management. High-temperature operation (≥100°C) enables simplified water management, but additional material stability challenges remain, particularly concerning the chemical stability of the anion-exchange membranes (AEMs). Herein, we report the synthesis of lightly branched poly(arylene piperidinium) AEMs, leading to balanced water management and sufficient stability. The optimized membranes demonstrate high-temperature H 2 /O 2 AEMFC operation at 100°C, with a peak power density of ∼2 W cm −2 and durability over a 195-h period under a constant current density of 600 mA cm −2 with only ∼4% voltage decay. This work illustrates an effective AEM design strategy through high-temperature operation to resolve water management issues, thereby improving AEMFC performance and durability.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2021
·Vol. 15
·期 4
·3195-3203
·
IF 8.897
Wang Yan,Gao Hexiang,Wu Wenjia,Zhou Zhuofan,Yang Zhiwei,Wang Jingtao,Zou Yecheng
Porous laminar membranes hold great promise to realize ultrafast ion transfer if efficient and stable transfer channels are constructed in vertical direction. Here, metal-organic framework (MOF) nanosheets bearing imidazole molecules in the pores were designed as building blocks to assemble free-standing MOF laminar membrane. Then, Nafion chains were threaded into the pores induced by electrostatic attraction from imidazole molecules by slowly filtering dilute Nafion solution. We demonstrate that the threaded Nafion chains lock adjacent MOF nanosheets, affording highly enhanced structural stability to the resultant laminar membrane with almost no water swelling. Significantly, abundant acid-base pairs are formed in the pores along Nafion chains, working as efficient, continuous conduction pathways in vertical direction. Proton conductivities as high as 110 and 46 mS·cm −1 are obtained by this membrane under 100% and 40% relative humidity (RH), respectively, which are two orders of magnitude higher than that of pristine MOF membrane. The conductivity under low humidity (40% RH) is even over 2 times higher than that of commercial Nafion membrane, generating the maximum power density of 1,100 mW·cm −2 in hydrogen fuel cell (vs. 291 mW·cm −2 of Nafion membrane). Besides, the influence of water state on proton transfer in confined space is investigated in detail.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 22
·47603
·
IF 2.188
Saad Ahmed,Muhammad Ali,Yangben Cai,Yunhua Lu,Zaheer Ahmad,Santosh Khannal,Shiai Xu
In the present study, multi-walled carbon nanotubes (MWCNTs) were sulfonated by 1,3-propane sultone and distillation–precipitation polymerization, respectively, and then incorporated into chitosan (CS) to prepare CS/MWCNTs composite membranes for fuel cell applications. CS/MWCNTs membranes show better thermal and mechanical stability than pure CS membrane due to the strong electrostatic interaction between the SO 3 H groups of MWCNTs and the NH 2 groups of CS, which can restrict the mobility of CS chain. The sulfonated MWCNTs provide efficient proton hopping sites ( SO 3 H, SO 3 − …. 3 + HN ), thereby resulting in the formation of continuous proton conducting channels. The composite membranes with 5 wt % of MWCNTs modified by two different ways show a proton conductivity of 0.026 and 0.025 S·cm −1 , respectively. In conclusion, CS/MWCNTs membrane is a promising proton exchange membrane for fuel-cell applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47603.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Xiang Qiu,Mitsuru Ueda,Huayuan Hu,Yuqian Sui,Xuan Zhang,Lianjun Wang
To improve proton conduction properties of conventional sulfonated poly(ether ether ketone) (SPEEK), poly(2,5-benzimidazole)-grafted graphene oxide (ABPBI-GO) was prepared to fabricate nanocomposite membranes, which then were further doped with phosphoric acid (PA). The ABPBI-GO was synthesized through the reaction of 3,4-diaminobenzoic acid with the carboxyl acid groups present on the GO surface. The simultaneous incorporation of ABPBI-GO and PA into SPEEK did not only improve the physicochemical performance of the membranes in terms of thermal stability, water uptake, dimensional stability, proton conductivity, and methanol permeation resistance but also relieve PA leaching from the membranes though acid–base interactions. The resulting composite membranes exhibited enhanced proton conductivities in extended humidity ranges thanks to the hygroscopic character of PA and the increased water uptake. Moreover, the unique self-ionization, self-dehydration, and nonvolatile properties of PA improved the high-temperature proton conductivities (σ) of PA-doped membranes. The PA-doped SPEEK/ABPBI-GO-3.0 delivered a σ of 7.5 mS cm–1 at 140 °C/0% RH. This value was fourfold higher than that of pristine SPEEK membranes. The PA-doped SPEEK/ABPBI-GO-3.0 based fuel cell membranes delivered power densities of 831.06 and 72.25 mW cm–2 at 80 °C/95% RH and 120 °C/0% RH, respectively. By contrast, the PA-doped SPEEK membrane generated only 655.63 and 44.58 mW cm–2 under the same testing conditions.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2018
·
IF 2.21
Wenjing Tu,Yue Sun,Dan Wu,Huibo Wang,Hui Huang,Mingwang Shao,Yang Liu,Zhenhui Kang
The engineering of electrocatalysts with high performance for methanol oxidation reaction (MOR) is of great urgency for the development of direct methanol fuel cells (DMFCs). Here, we designed and fabricated cobalt oxyhydroxide and carbon dots modified by platinum (Pt-CoOOH-CDs/C) hybrids with low content of Pt (13 wt%) as electrocatalyst, which exhibit high activity (856.3 mA·mg −1 Pt ), stability (3 h) and better anti-poisoning ability for MOR. The Pt-CoOOH-CDs/C was synthesized by precipitate method followed with photochemical deposition. In the catalytic system, the Pt nanoparticles serve as the active center toward MOR, CoOOH-CDs use as the co-catalyst to oxidize CO-like poisonous species to CO 2 on neighbouring Pt sites, and the cost-efficient carbon black enhances the conductivity for the system. The cost-efficient Pt-CoOOH-CDs/C system with improved kinetics for anodic methanol oxidation has promising application in alkaline DMFCs.
研究领域:
化学
·
能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2020
·
IF 9.567
Xiaobai Li,Hongwei Ma,Peng Wang,Zhenchao Liu,Jinwu Peng,Wei Hu,Zhenhua Jiang,Baijun Liu,Michael D. Guiver
Phosphoric acid-doped polybenzimidazole (PA-PBI) used in high-temperature proton exchange membranes (HT-PEMs) frequently suffers from a serious loss of mechanical strength because of the “plasticizing effect” of the dopant acid. Conventional cross-linking approaches generally enhance membrane stability. However, acid doping levels (ADLs) and consequently proton conductivity inevitably decrease. This is due to the formation of more compact molecular structures and a reduced amount of functional imidazole units, caused by their consumption in introducing the cross-linker. To resolve the common problems of current PA-PBI-based HT-PEMs, herein, a highly acidophilic imidazole-rich cross-linked network with superior “antiplasticizing” ability is constructed based on a novel multifunctional cross-linker. This unique bischloro/bibenzimidazole (“A2B2-type”) molecular structure has extremely high reactivity, including “self-reaction” among the cross-linkers and “inter-reaction” between the cross-linker and PBI molecules. The resulting imidazole-rich cross-linked membranes exhibit the desired combination of high ADLs, high conductivity, outstanding dimensional–mechanical stability, and excellent fuel cell performance. In comparison to a corresponding linear PBI membrane, one membrane with a high content of the cross-linker of 30% has a 100 wt % increased acid uptake, a doubling in proton conductivity at 200 °C, and a maximum power density of 533 mW·cm–2 at 160 °C without humidification.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Xiaomeng Li,Ming Wen,Dandan Wu,Qingsheng Wu,Jiaqi Li
For the exploration of catalysts with excellent performance in alkaline fuel cells, high-performance two-dimensional (2D) Pd-on-NiCu nanosheets were synthesized through the kinetics controlling synthesis of NiCu nanosheets followed by Pd nanoparticles (NPs) embedding treatment at room temperature. In which case, well-dispersed Pd NPs with the average diameter of ∼4 nm are embedded on NiCu nanosheets (BET surface area of 180.7 m 2 g −1 ). Pd-on-NiCu nanosheets exert remarkable high performance in electrocatalytic activity, methanol-tolerance and stability, the electrocatalytic mass activity of Pd-on-NiCu nanosheets is 1827 mAmg −1 , which is over 6-fold higher than that of commercial Pd/C (289 mAmg −1 ), and the current density of the electrocatalyst decreases after 300 cycles of only 6%. Therefore, Pd-on-NiCu nanosheets can be considered as one of the most promising candidates for fuel cells applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2014
·
IF 1.552
Li Meng,Fangzhong Wang,Ao Wang,Jian Pu,Bo Chi,Jian Li
La 0.8 Sr 0.2 MnO 3 (LSM)-coated Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3 (BSCF) composite powder (LSM-BSCF) was synthesized by a novel solid-solution method and investigated electrochemically as a cathode material for intermediate temperature solid oxide fuel cells. The cathode combined the merits of LSM and BSCF cathodes through an extended triple phase boundary and stabilized microstructure and demonstrated a polarization resistance between 0.61 and 0.09 Ω cm 2 at 600 to 750 °C. Compared with high performance cathodes prepared by solution impregnation, this LSM-BSCF cathode greatly improved performance stability.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Nature Energy
·
2022
·Vol. 7
·期 2
·153-162
·
IF 67.439
Tang Hongying,Geng Kang,Wu Lei,Liu Junjie,Chen Zhiquan,You Wei,Yan Feng,Guiver Michael D.,Li Nanwen
Conventional proton exchange membrane fuel cells (PEMFCs) operate within narrow temperature ranges. Typically, they are run at either 80‒90 °C using fully humidified perfluorosulfonic acid membranes, or at 140‒180 °C using non-humidified phosphoric acid (PA)-doped membranes, to avoid water condensation-induced PA leaching. However, the ability to function over a broader range of temperature and humidity could simplify heat and water management, thus reducing costs. Here we present PA-doped intrinsically ultramicroporous membranes constructed from rigid, high free volume, Tröger’s base-derived polymers, which allow operation from −20 to 200 °C. Membranes with an average ultramicropore radius of 3.3 Å show a syphoning effect that allows high retention of PA even under highly humidified conditions and present more than three orders of magnitude higher proton conductivity retention than conventional dense PA-doped polybenzimidazole membranes. The resulting PA-doped PEMFCs display 95% peak power density retention after 150 start-up/shut-down cycles at 15 °C and can accomplish over 100 cycles, even at −20 °C.
研究领域:
材料科学
·
能源工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）