高温质子交换膜燃料电池用离子液体聚合物电解质的研究进展

综述了近十几年来高温质子交换膜燃料电池用离子液体聚合物电解质的研究进展及其在高温质子交换膜燃料电池中的应用进展,指出了此类电解质目前存在的亟待解决的两个问题：咪唑类离子液体毒化Pt基催化剂和复合膜中离子液体的长期稳定性。最后对高温质子交换膜燃料电池用离子液体聚合物电解质的发展前景作了展望,即开发与Pt基催化剂相容的离子液体聚合物电解质以及预防复合膜内离子液体的流失,即提高高温质子交换膜燃料电池的性能及长期稳定性,最终提高高温燃料电池的寿命。     

离子液体嵌段聚合物的应用研究进展

对聚合离子液体嵌段共聚物在电解质、CO2分离膜、聚偏氟乙烯(PVDF)膜改性剂等方面的最新应用研究进展进行综述。最后讨论了目前离子液体嵌段聚合物在发展中存在的问题,并展望了离子液体嵌段聚合物的发展前景。     

氮杂环离子液体及其衍生物在高温质子交换膜中的应用研究进展

回顾了近年来氮杂环类离子液体作为离子传导介质在高温质子交换膜中的应用,主要体现在直接物理掺杂、高分子主链修饰改性、采用无机有机复合技术在膜内锚固3个方向。采用离子液体与聚合物电解质直接掺杂所制备的质子交换膜在高温条件下表现出了优异的质子传导性能,但离子液体容易随电极反应生成的水而流失,进而造成电池性能下降的缺点限制了其实际应用;采用离子液体单元对高分子主链进行修饰可以实现离子液体在质子交换膜内的固定,而复杂的合成工艺以及离子液体单元的低柔顺性导致的低电导率是其存在的缺点;通过离子液体修饰的无机纳米氧化物与聚合物电解质的掺杂也可以实现离子液体在质子交换膜中的固定,这类膜材料的制备难点在于连续质子传导相的形成以及提高离子液体单元的可移动性。在对上述3个主要研究方向的特点进行概括和评述的基础上,指出通过有机无机复合技术实现离子液体在质子交换膜内的固定并提高离子液体的局部柔顺性是未来高温质子交换膜的重点研究方向。     

燃料电池用碱性膜材料的研究进展

碱性膜直接甲醇燃料电池因为结合了质子交换膜燃料电池和液体碱燃料电池的优点而产生自身独特的性质,使其可以在一定程度上弥补质子交换膜燃料电池以及液体碱燃料电池的缺点而尤其引人关注。其中碱性膜电解质为碱性膜燃料电池的核心组件,其性能直接关系到燃料电池的性能及寿命。截至目前,关于碱性膜材料的制备及应用方面的报道较多,涉及的碱性膜电解质的种类也较多。本文以燃料电池用碱性膜电解质为综述内容,对国内外关于碱性膜电解质的研究报道进行系统的梳理和介绍。     

燃料电池高温质子交换膜研究进展

高温质子交换膜燃料电池具有反应动力学快、CO耐受性高等特点,但磷酸掺杂的高温质子交换膜因磷酸的流失和聚合物的降解等原因导致燃料电池的输出功率发生衰减。本文通过介绍聚苯并咪唑衍生物的高温质子交换膜、聚苯并咪唑的复合型质子交换膜、新型芳基聚合物的高温质子交换膜,阐明聚合物的主链结构、官能团结构以及复合填料对高温质子交换膜性能的影响。在近期的研究报道中,提高膜性能的主要策略包括提升自由体积、建立交联结构、嵌段共聚、复合掺杂（ILs、MOFs、PIMs、MO_x）、阳离子官能团修饰等。文章指出,在未来的研究中应该加强对磷酸基高温质子交换膜质子传输通道结构的进一步理解,关注聚合物化学降解和物理性能衰败的原因,并开发更多的新型聚合物材料。     

用于燃料电池的聚合物电解质膜及其改性方法

聚合物电解质膜是质子交换膜燃料电池的核心部件.目前广泛使用的全氟质子交换膜(如Nafion(R)系列)存在着价格昂贵、使用温度有限、甲醇渗透率高以及降解再生困难等缺点.对聚合物基质材料进行物理或化学改性,可以提高质子传导率、改善机械强度等性能,获得高性能、低成本的质子交换膜.从聚合物材料改性的角度,综述了燃料电池用聚合物电解质膜的制备方法和电化学性能,并对各种改性方法进行了比较.     

氧化石墨烯在燃料电池质子交换膜中的应用

保护环境，开发环保型能源，对人类和社会具有重要意义。质子交换膜燃料电池由于其能量转化率高，可实现零排放，近年来引起了电池领域研究者们的兴趣。氧化石墨烯（GO）由于存在活性氧官能团，可以和离子型聚合物进行复合以制备复合质子交换膜。氧化石墨烯类的复合质子交换膜应用于燃料电池时可以提高膜在高温低湿度条件下的质子传导率，降低甲醇渗透率，提高电池的功率密度。本文首先介绍了氧化石墨烯的制备方法，然后从不同的离子型聚合物基质复合质子交换膜的类别出发，详细介绍了氧化石墨烯在Nafion、聚醚醚酮、聚苯并咪唑和壳聚糖等不同种类的离子型聚合物中的应用现状及作用机理，同时对其在质子交换膜的应用方面存在的问题及应用前景做了评论和展望。     

用于质子交换膜的高质子传导率聚合物研究进展

质子传导率超过Nafion膜的质子交换膜是近年来研究的焦点。质子交换膜的质子传导率与它们的IEC值和形态有关。形成离子通道是开发高质子传导率的质子交换膜的一种有效方法。形成离子通道主要有3种:1)用嵌段共聚物的微相分离;2)侧链和支链磺化的聚合物;3)局部区域的高密集磺化。此外,与无机纳米材料形成纳米复合材料的质子交换膜也能提高质子交换膜的质子传导率及质子交换膜的机械强度、尺寸稳定性、耐氧化稳定性等性能。综述了关于用于高质子传导率的燃料电池质子交换膜(PEM)的聚合物的研究进展。对高质子传导率的燃料电池膜聚合物的发展趋势进行了展望。     

聚醚砜-聚乙烯吡咯烷酮高温聚合物电解质膜及燃料电池堆性能研究

基于磷酸掺杂聚苯并咪唑膜（PA/PBI）的高温聚合物电解质膜燃料电池具有高的输出功率和优异的稳定性,然而PBI膜昂贵的价格和复杂的制备工艺限制了高温聚合物电解质膜燃料电池的商业化应用。本研究以成本低和制备工艺简单的聚醚砜-聚乙烯吡咯烷酮（PES-PVP）膜的商业化应用为目标,小规模制备了幅宽为40 cm的PES-PVP复合膜,证实了流延法放大制备PES-PVP复合膜的可行性。PES-PVP膜中每个PVP重复单元的吸附量达4.9个磷酸（PA）分子,且在180℃的质子电导率达85 mS·cm^-1。此外,尺寸为165 cm²的PA/PES-PVP高温膜电极在150℃的输出功率达0.19 W·cm^-2@0.6 V,与同尺寸的商业化PA/PBI高温膜电极的输出功率相当,并在近3000 h的寿命测试中展示出良好的稳定性。最后,将PA/PES-PVP高温膜电极（单片有效面积200 cm²）组装高温膜燃料电池短堆,其中基于3片膜电极的短堆展现出良好的电堆启停稳定性;基于20片膜电极电堆的峰值功率达1.15 kW。以上结果表明所制备的PA/PES-PVP是一种性能优良、价格便宜的高温聚合物电解质膜材料,并且基于该膜材料组装的高温聚合物电解质膜电池和电堆性能优异。本研究工作为高温聚合物电解质膜燃料电池关键材料和电堆的国产化提供了研究基础。     

直接甲醇燃料电池用阻醇质子交换膜研究进展

直接甲醇燃料电池是近十年兴起的新型燃料电池,并以其独特的优点引起了人们广泛的关注。作为其重要组成部分的质子交换膜的性质是影响电池性能的关键因素。本文在介绍近两年质子交换膜研究最新进展的基础上,综述了天然聚合物用作质子交换膜材料的研究情况,并分析了其优劣势及应用前景。     

A synthesis study of phosphonated PSEBS for high temperature proton exchange membrane fuel cells

A series of novel phosphonated proton exchange membranes has been prepared using poly(styrene‐ethylene/butylene‐styrene) block copolymer (PSEBS) as base material. Phosphonic acid functionalization of the polymer was performed by a simple two‐step process, via chloromethylation of PSEBS followed by phosphonation utilizing the Michaels–Arbuzov reaction. The successful phosphonation of the polymers were characterized by NMR and Fourier transform infrared. The phosphonated ester form of the membranes were obtained by solvent evaporation method and hydrolyzed to get a proton conducting membrane. The membrane properties such as ion exchange capacity, water uptake and proton conductivity at various temperatures were examined for their suitability to be utilized as a high temperature polymer electrolyte. Additionally, the morphology, thermal, and mechanical properties of the synthesized membranes were investigated, using scanning electron microscope, thermogravimetric analysis, and tensile test, respectively. The effective (anhydrous) proton conductivity was studied with respect to various degrees of functionalization. From the studies, the membranes were found to have a comparatively good conductivity and one of the membranes reached the maximum value of 5.81 mS/cm² at 140 °C as measured by impedance analyzer. It was found that the synthesized membranes were mechanically durable, chemically, and thermally stable. Hence, the synthesized phosphonated membranes could be a promising candidate for high temperature polymer electrolyte fuel cell applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45954.     

Polymer membranes for high temperature proton exchange membrane fuel cell: Recent advances and challenges

Proton-exchange membrane fuel cells (PEMFCs) are considered to be a promising technology for efficient power generation in the 21st century. Currently, high temperature proton exchange membrane fuel cells (HT-PEMFC) offer several advantages, such as high proton conductivity, low permeability to fuel, low electro-osmotic drag coefficient, good chemical/thermal stability, good mechanical properties and low cost. Owing to the aforementioned features, high temperature proton exchange membrane fuel cells have been utilized more widely compared to low temperature proton exchange membrane fuel cells, which contain certain limitations, such as carbon monoxide poisoning, heat management, water leaching, etc. This review examines the inspiration for HT-PEMFC development, the technological constraints, and recent advances. Various classes of polymers, such as sulfonated hydrocarbon polymers, acid-base polymers and blend polymers, have been analyzed to fulfill the key requirements of high temperature operation of proton exchange membrane fuel cells (PEMFC). The effect of inorganic additives on the performance of HT-PEMFC has been scrutinized. A detailed discussion of the synthesis of polymer, membrane fabrication and physicochemical characterizations is provided. The proton conductivity and cell performance of the polymeric membranes can be improved by high temperature treatment. The mechanical and water retention properties have shown significant improvement., However, there is scope for further research from the perspective of achieving improvements in certain areas, such as optimizing the thermal and chemical stability of the polymer, acid management, and the integral interface between the electrode and membrane.     

Trends for fuel cell membrane development

Fuel cells are considered a promising energy conversion technology of the future owing to inherent advantages of electrochemical conversion over thermal combustion processes. In the polymer electrolyte fuel cell (PEFC) a proton-conducting polymer membrane is utilized as solid electrolyte, having to allow the transport of protons from anode to cathode yet block the passage of reactants (e.g. H₂, O₂) and electrons. Although PEFC technology has matured substantially over the past two decades, technological barriers, such as insufficient durability and high cost, still delay commercialization in many applications. In this contribution, we review current fuel cell membrane technology and outline approaches that are taken to improve the functionality as well as the chemical and mechanical stability of proton conducting polymers in fuel cells.     

Synthesis and Characterization of a New Fluorine‐Containing Polybenzimidazole (PBI) for Proton‐Conducting Membranes in Fuel Cells

A new type of fluorine‐containing polybenzimidazole, namely poly(2,2′‐(2,2′‐bis(trifluoromethyl)‐4,4′‐biphenylene)‐5,5′‐bibenzimidazole) (BTBP‐PBI), was developed as a candidate for proton‐conducting membranes in fuel cells. Polymerization conditions were experimentally investigated to achieve high molecular weight polymers with an inherent viscosity (IV) up to 1.60 dl g^–1. The introduction of the highly twisted 2,2′‐disubstituted biphenyl moiety into the polymer backbone suppressed the polymer chain packing efficiency and improved polymer solubility in certain polar organic solvents. The polymer also exhibited excellent thermal and oxidative stability. Phosphoric acid (PA)‐doped BTBP‐PBI membranes were prepared by the conventional acid imbibing procedure and their corresponding properties such as mechanical properties and proton conductivity were carefully studied. The maximum membrane proton conductivity was approximately 0.02 S cm^–1 at 180 °C with a PA doping level of 7.08 PA/RU. The fuel cell performance of BTBP‐PBI membranes was also evaluated in membrane electrode assemblies (MEA) in single cells at elevated temperatures. The testing results showed reliable performance at 180 °C and confirmed the material as a candidate for high‐temperature polymer electrolyte membrane fuel cell (PEMFC) applications.     

Cost effective cation exchange membranes: A review

This paper will look at developments of new polymer electrolyte membranes to replace high cost ion exchange membranes such as Nafion^®, Flemion^® and Aciplex^®. These perfluorinated polymer electrolytes are currently the most commercially utilized electrolyte membranes for polymer electrolyte fuel cells, with high chemical stability, proton conductivity and strong mechanical properties. While perfluorinated polymer electrolytes have satisfactory properties for fuel cell applications, they limit commercial use due to significant high costs as well as reduced performance at high temperatures and low humidity. A promising alternative to obtain high performance proton-conducting polymer electrolyte membranes is through the use of hydrocarbon polymers. The need for inexpensive and efficient materials with high thermal and chemical stability, high ionic conductivity, miscibility with other polymers, and good mechanical strength is reviewed in this paper. Though it is difficult to evaluate the true cost of a product based on preliminary research, this paper will examine several of the more promising materials available as low cost alternatives to ion exchange membranes. These alternative membranes represent a new generation of cost effective electrolytes that can be used in various ion exchange systems. This review will cover recent and significant patents regarding low cost polymer electrolytes suitable for ion exchange membrane applications. Promising candidates for commercial applications will be discussed and the future prospects of cost effective membranes will be presented.     

Aliphatic SPI charge‐transfer complex hybrid films for high temperature polymer electrolyte membrane fuel cells

A new method to synthesize polymer electrolyte membranes based on charge‐transfer (CT) complexes for high temperature fuel cells is investigated. Aliphatic sulfonated polyimide (SPI) CT complex hybrid films are prepared. Aliphatic units are introduced into the SPI main chain to increase the elasticity compared with aromatic SPI films. Electron‐donating compounds are included to form a CT complex, resulting in improved control over mechanical strength, water uptake, and thermal stability. The resulting thermal properties of the SPI CT films are sufficient to operate at elevated temperature (up to 120 °C), and the proton conductivity is comparable to that of Nafion 115. These films are thus promising alternative membranes for high temperature polymer electrolyte fuel cell applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46087.     

Organic-inorganic composite membranes as addition of SiO2 for high temperature-operation in polymer electrolyte membrane fuel cells (PEMFCs)

Organic-inorganic composite membranes for operation above 100 °C in polymer electrolyte membrane fuel cells (PEMFCs) were prepared, characterized and cell-tested. Composite membranes were obtained by mixing organic polymers, which have a SO₃H group as a proton conductor with inorganic material, SiO₂, using the sol-gel process. Electron probe micro analyser (EPMA) was used to show the homogeneous and uniform distribution of SiO₂. The physico-chemical properties of all membranes were investigated regarding their tensile strength, water uptake and thermogravimetric analyzer (TGA). Due to a higher water uptake and thermal stability of composite membranes, the cell performances at high temperatures above 100 °C, were improved. In addition, the SiOH group in the composite membrane was shown to play a major role in capturing water strongly and maintaining proton conductivity even at high temperature. Furthermore, the fuel cell performance of organic-inorganic composite membranes was superior to that of the Nafion membrane at high current density over all ranges of temperature.     

Proton-conducting polymer electrolyte membranes based on hydrocarbon polymers

This paper presents an overview of the synthesis, chemical and electrochemical properties, and polymer electrolyte fuel cell applications of new proton-conducting polymer electrolyte membranes based on hydrocarbon polymers. Due to their chemical stability, high degree of proton conductivity, and remarkable mechanical properties, perfluorinated polymer electrolytes such as Nafion^®, Aciplex^®, Flemion^®, and Dow membranes are some of the most promising electrolyte membranes for polymer electrolyte fuel cells. A number of reviews on the synthesis, electrochemical properties, and fuel cell applications of perfluorinated polymer electrolytes have also appeared during this period. While perfluorinated polymer electrolytes have satisfactory properties for a successful fuel cell electrolyte membrane, the major drawbacks to large-scale commercial use involve cost and low proton-conductivities at high temperatures and low humidities. Presently, one of the most promising ways to obtain high performance proton-conducting polymer electrolyte membranes is the use of hydrocarbon polymers for the polymer backbone. The present review attempts for the first time to summarize the synthesis, chemical and electrochemical properties, and fuel cell applications of new proton-conducting polymer electrolytes based on hydrocarbon polymers that have been made during the past decade.     

Preparation and DMFC performance of a sulfophenylated poly(arylene ether ketone) polymer electrolyte membrane

A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily prepared PEEKK by post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported similarly structured analogues and MEAs derived from comparative Nafion^® membranes.