EUROPEAN POLYMER JOURNAL
·
2016
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IF 3.485
Quan Yuan,Guo-Hua Sun,Ke-Fei Han,Jing-Hua Yu,Hong Zhu,Zhong-Ming Wang
A series of copolymers, which can also be regarded as ABPBIs containing phenoxyl in the main chain, were synthesized by copolymerization of two kinds of self-polycondensation monomers: 3,4-diaminobenzoic acid (DABA) and 4-(3,4-diamino-phenoxy)-benzoic acid (DPBA). The phenoxyl-containing ABPBIs exhibit better processability and acid stability than original ABPBI, despite their affinities towards acid decrease with the addition of phenoxyl moieties. By adjusting the phenoxyl content of the polymer, we made a tradeoff between acid doping levels and proton conductivity, with mechanical properties. The optimal polymer therein, PO-AB-50 (50 M percentages of DPBA in total monomers), exhibits considerable proton conductivity (53.47 mS/cm at 160 °C) and tensile strength (1.9 MPa) after doped with phosphoric acid. In addition, the oxidation stability, water uptake and swell ratio properties of the polymers were also improved with the introduction of phenoxyl moieties.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Polymer-Plastics Technology and Materials
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2020
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IF 0
Shanshan Wang,Qifeng Li,Fanghui Wang
Designed and synthesized a series of imidazolium-functionalized Poly (2, 6-dimethyl-1, 4-phenylene oxide) (Im-PPO) containing pendant imidazole groups, which were used to supply functional sites for acid–base interaction with the doping phosphoric acid. The imidazolium-functionalized Poly (2, 6-dimethyl-1, 4-phenylene oxide) membranes obtained by the solution-casting method were doped with phosphoric acid (PA). The PA content, swelling, and tensile strength of the different membranes doped with PA were measured. With the increase of the length of side chains on the imidazole groups, the membrane showed different properties. The proton conductivity at a level of 3.7 × 10−2 S/cm was achieved at 160°C by the MeIm-PPO imidazolium composite membrane.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 2
·024502
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IF 4.386
Chao Meng,Dongmei Han,Shan Ren,Shuanjin Wang,Min Xiao,Yuezhong Meng
In the present work, a cross-linked high-temperature proton exchange membrane based on poly [2, 2'-(p-oxydiphenylene)-5, 50-benzimidazole] (OPBI), imidazole (Im) and hexachlorocyclotriphosphazene (HCCP) was prepared and characterized, aiming at their future application in fuel cell devices. The composite membranes were characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), energy dispersive X-ray (EDX) and thermogravimetric analysis (TGA). The results show that the PBI are successfully cross-linked by the cross-linking agent, and the membranes are uniform and compact, with excellent thermal stability. Phosphoric acid (PA) doped crosslinked membranes have excellent mechanical properties and proton conductivities. The tensile strength of PA-doped PBI-ImCCP-20% at room temperature is 20 MPa, and the proton conductivity reaches 53 mS cm−1 at 160 °C without humidification. H2/O2 fuel cell assembled with PA-doped PBI-ImCCP-20% membrane delivered a peak power density of 749 mW cm−2 at 160 °C under anhydrous conditions. The excellent performance of PBI-ImCCP series cross-linked membranes makes them potential candidate for HT-PEMFC applications.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 28
·17243-17251
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IF 10.7
Sifan Chen,Zhuang Ma,Jialin Zhang,Jianchun Niu,Shuomeng Zhang,Qinghua Zhang,Shiyuan Chen,Shanfu Lu,Miao Wang,Qinggang He
Proton-exchange membranes are considered the core of high-temperature proton-exchange membrane fuel cells (HT-PEMFCs) and determine the output power of the cells. However, current HT-PEMs, which are mainly doped with phosphoric acid (PA), face challenges such as low conductivity and loss of PA during cell operation. In this study, cardo poly(biphenyl indole) membranes (POXIA-QA) with quaternary ammonium salt terminals and tunable side-chain lengths were designed at the molecular level. The rational structural design enabled PA to form a continuous hydrogen-bonding network in POXIA-QA, which could be effectively immobilized and retained. The proton conductivity and activation energy patterns were found to be inconsistent with the PA doping level, suggesting that proton transportation depends not exclusively on the amount of PA but also on the PA distribution induced by the acidic spacer. The polymer membrane bearing a hexyl side chain spacer exhibited excellent proton conductivity (0.113 S cm−1 at 180 °C) and single-cell power density (1001.3 mW cm−2 at 180 °C). This study provides insights into the microphase separation, PA distribution, proton transfer, and high-temperature fuel cell performance of phosphonic acid-doped HT-PEMs with side chains and establishes structure–performance relationships. This study is expected to provide a theoretical basis and suitable candidate materials for the design of HT-PEMs.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2020
·
IF 7.183
Yiming Xiao,Shihao Wang,Guiying Tian,Jun Xiang,Lei Zhang,Penggao Cheng,Jianping Zhang,Na Tang
Phosphoric acid-doped polybenzimidazole membranes have exhibited great potential in high-temperature proton exchange membrane applications, but proton conductivity and stability should be further improved for high performance fuel cells . Herein, a series of grafted polybenzimidazoles containing benzimidazole type side pendant were successfully prepared by facile N-substitution reaction without any catalyst. These grafted polybenzimidazole membranes with side chains of benzimidazole group exhibit excellent properties in the doping level of phosphoric acid, retention stability of phosphoric acid and proton conductivity under certain mechanical properties , oxidation resistance and thermal stability. Importantly, the phosphoric acid (PA) retention stability and proton conductivity can be preciously controlled by adjusting the length of side chain and the number of benzimidazole groups. With the acid doping level of 19.3, the grafted membrane exhibits a high conductivity of 101 mS cm −1 and a great power density of 305 mW cm −2 at 160 °C without humidification. The molecular dynamics simulation show that the improved performance of the grafted membrane is mainly due to the increase in the free volume of the polymer membrane, the enhancement of the binding energy and the densification of the hydrogen bond network structure between the polymer membrane and phosphoric acid.
研究领域:
材料科学
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燃料电池研究
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
Yu Bai,Dongmei Han,Min Xiao,Zhiheng Huang,Chengxin Wang,Shuanjin Wang,Yuezhong Meng
Polypyrrolone (PPy) possesses excellent heat resistance and mechanical properties , moreover, the N-heterocycle contained in the PPy allows the absorption of phosphoric acid (PA) for proton conduction. In the present work, PPy is synthesized by a two-step method and evaluated for the first time as the polymeric material for high temperature proton exchange membranes (HT-PEMs). The PA-doped PPy membrane reaches a peak power density of 582 mW cm −2 at 160 °C under fully anhydrous conditions, besides, the fuel cell exhibits excellent durability over a period of 300 h with a load voltage decay of only 0.032% per hour and remains 0.647 V after the test. Further, the PPy-impregnated polyimide (PI) nanofiber mat composite membrane (PI@PPy) with an optimal thickness is fabricated with enhanced dimensional stability, of which acid swelling ratio noticeably declined by 51% in area and 25% in volume. A higher peak power density (634 mW cm −2 ) and less cell voltage reduction is also observed in the composite membrane, benefits from the trade–off between proton conductivity and PA retention ability. The results of the present study may contribute to further studies on polypyrrolone-based HT-PEMs and composite membranes.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Xue Tian,Shuang Wang,Jinsheng Li,Fengxiang Liu,Xu Wang,Hao Chen,Hongzhe Ni,Zhe Wang
Polybenzimidazole (PBI)/ionic liquid (IL) functional Si–O–Si network composite membranes are prepared from PBI with 1-(3-trimethoxysilylpropyl)-3-methylimidazolium chloride. The IL can be hydrolyzed to form Si–O–Si network structure under acidic conditions. And such IL functional Si–O–Si network (NP) in the composite membranes could improve phosphoric acid doping levels and proton conductivities simultaneously. The ability of retaining more PA is also reflected in the high proton conductivity value of PBI/NP-15% membrane which shows almost three-fold increment compared to the pristine PBI. All the PBI/NP-X composite membranes display excellent chemical stability and improved mechanical strength . This is attributed to Si–O–Si network structure. Moreover, PBI/NP composite membranes have demonstrated high thermal stability up to 250 °C, which is attractive for high-temperature (>200 °C) proton exchange membrane fuel cells.
研究领域:
材料科学
·
燃料电池技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2022
·
IF 9.794
Yiming Xiao,Xiaoyu Shen,Ranxin Sun,Songbo Wang,Jun Xiang,Lei Zhang,Penggao Cheng,Xinjun Du,Zhen Yin,Na Tang
Polybenzimidazole (PBI) membrane doped with phosphoric acid (PA) usually requires the high PA doping level (ADL) to ensure excellent proton conductivity , however, the loss of PA can lead to dramatical attenuation of fuel cell performance . Herein, we develop a facile way to enhance the proton conductivity and stability of poly[2,2′-(p-oxydiphenylene)-5,5′-benzimidazole (OPBI) membranes at much low ADL (about 80% of OPBI membrane) via construction of proton transport pathways between ionic liquids (ILs), carbon nanotubes (CNTs) and PA. Owing to the anionic and cationic structures of ILs and the adsorption of CNTs on PA, abundant proton transport pathways can be constructed to guarantee superior proton conductivity and durability of hybrid OPBI membrane (ILs/CNTs/OPBI) with low ADL. The as-prepared 10%-ILs/NH 2 -CNTs/OPBI hybrid membrane exhibits the highest proton conductivity (130.8 mS cm −1 ) and stability (above 119 mS cm −1 after 228 h test) at 160 °C, much better than other ILs/CNTs/OPBI hybrid membranes and OPBI membranes. More importantly, a fuel cell based on ILs/NH 2 -CNTs/OPBI membrane achieves the highest power density of 508 mW cm −2 at 160 °C, 2.7 times higher than that of OPBI membranes (189 mW cm −2 ). Good durability of a single cell with ILs/NH 2 -CNTs/OPBI membranes is also confirmed in steady-state and restart tests.
研究领域:
材料科学
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燃料电池技术
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Han Sun,Shuang Wang,Yinghe Cui,Zhipeng Yong,Dan Liang,Xiaodong Wang,Xiaorui Wang,Chenglong Li,Feng Pan,Zhe Wang
Branched polymers have unique three-dimensional dendritic structures, so they have received a lot of attention in the application of high temperature proton exchange membranes . In this work, we synthesize BOPBI-X (X = 3%, 6%, 9%) membranes with different branched ratios based on the synthesis of OPBI, due to the introduction of a rigid triazine structure with a larger free volume, the membranes could absorb more phosphoric acid (PA) while maintaining sufficient mechanical strength . Among them, the BOPBI-6% membrane obtains splendid comprehensive performance, when the PA doping level (ADL) is 9.55, it achieves a proton conductivity of 99.2 mS cm −1 at 180 °C, which is 1.8 times higher than OPBI (54.8 mS cm −1 ), and it performs well in long-term oxidation stability test after 144 h, it still has a mass retention rate of 90%. For the sake of further boost the performance of the membrane, cross-linkable polymeric ionic liquid (PIL) is introduced to the system. Among them, BOPBI-PIL-30% membrane has sufficient mechanical properties (5.50 ± 0.8 MPa), and the proton conductivity (146.9 mS cm −1 ) at 180 °C is also excellent, so BOPBI-PIL-30% membrane is expected to be a promising candidate as HT-PEMs.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2018
·
IF 6.945
Xiaobai Li,Peng Wang,Zhenchao Liu,Jinwu Peng,Chengying Shi,Wei Hu,Zhenhua Jiang,Baijun Liu
Phosphoric acid-doped polybenzimidazole membranes offer great potential for high-temperature proton exchange membrane applications due to their high proton conductivity at high-temperature and low-humidity conditions. However, it remains a major challenge in fabricating high-performance membranes with both high proton conductivity and good mechanical strength . Here, a series of polybenzimidazoles with increased imidazole groups are obtained by incorporating some benzimidazole groups onto an arylether-type polybenzimidazole backbone via a simple and efficient N-substituted reaction without catalyst. This arylether-type polybenzimidazole is verified to exhibit good solubility under extremely high molecular weight , and it provides the possibility for fabricating the high mechanical strength membranes at high phosphoric acid doping levels. It is of interest to find that the introduction of additional bulky benzimidazole moieties even enhance the mechanical strength of the membranes, and at the same time, significantly improve their acid doping levels, acid doping rate and proton conductivity. Importantly, the acid-doped grafted membranes show superior dimensional-mechanical stability even at high acid loading. With an acid doping level of 22.1, the grafted membrane displays a high conductivity of 212 mS cm −1 at 200 °C without humidification . A H 2 /O 2 fuel cell based on this membrane has a peak power density of 443 mW cm −2 at 160 °C.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2020
·
IF 7.183
Jiayu Yang,Xiaobai Li,Chengying Shi,Bairun Liu,Kaiyue Cao,Cengliang Shan,Wei Hu,Baijun Liu
Because of the harsh operating circumstances of high temperature over 100 °C and strong acidity, it is of great significance to explore some new methods on the developments of high-performance membrane materials using in high-temperature proton exchange membrane fuel cells (HT-PEMFCs). In current work, with the assistance of newly designed sulfonated poly (aryl ether ketone) (SPAEK) compatibilizer , some hydrophilic and acidophilic polyhedral-oligosilsesquioxane nanoparticles bearing sulfuric acid groups (SPOSS) were successfully incorporated into a soluble arylether-type polybenzimidazole (Ph-PBI) matrix via an in situ sol-gel process to obtain a new family of hybrid membranes with an improved overall performance. As a result, these hybrid membranes exhibited enhanced acid absorption ability and doping levels at 120 °C, improved acid retention ability and attractive mechanical-dimensional stability. More importantly, the proton conductivity of a phosphoric acid doped hybrid membrane reached 126 mS cm −1 at 200 °C. This membrane was also suitable for membrane electrode assemblies (MEAs), and a maximum power density of 300 mW cm −2 could be achieved at 160 °C without humidity.
研究领域:
材料科学
·
燃料电池技术
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Chang Dong,Xin Xu,Jin Zhang,Haining Wang,Yan Xiang,Haijin Zhu,Maria Forsyth,Shanfu Lu
Introduction of porous structure to high temperature polymer electrolyte membranes is one of effective pathways to increase their proton conductivity under elevated temperature. However, the effect of the porous structure on the proton diffusion mechanism of these membranes is still unclear. In this work, the proton transport behaviour of a series of porous triazole-polysulfone (PSf) membranes under elevated temperature is comprehensively investigated. The functional triazole ring in the framework of porous triazole-PSf acts a proton acceptor to form acid-base pair with phosphoric acid (PA). In addition, the proton diffusion coefficient and proton conductivity of PA-doped porous triazole-PSf is an order of magnitude higher than that of the PA-doped dense triazole-PSf membrane. Percolation theory calculation convinces that the high proton conductivity of PA-doped porous triazole-PSf is due to the formation of continuous long-range proton diffusion channels under high pore connectivity and porosity. On the contrary, excessive pore connectivity also results in high gas permeability , leading to decrease of the open circuit voltage and cell performance of the single cell. Consequently, the optimum porosity for the PA-doped porous triazole-PSf membrane is 75% for fuel cell operating with the maximum peak power density of 550 mW·cm −2 and great durability for 120 h under 140 °C.
研究领域:
材料科学
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能源科学
✓ 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）