In last two decades, acid doped polybenzimidazole as polymer electrolyte membrane (PEM) has been widely recognized and envisioned as “ideal” proton conducting materials for application in high temperature PEM fuel cell (HT-PEMFC). The majority of research and developmental work is mainly focused on poly (2,2´-m-phenylene-5,5´-bibenzimidazole), However, it is neither easy-processed nor inexpensive component of the respective family. On the other hand, among the various members belonging to benzimidazole family, poly (2,5-benzimidazole) is unique because it possesses a cost-attractive, single-step synthesis process, high extent of doping as well as good chemical and thermal stability. In the recent years this material has proved its potency in the earlier research. Thus this review puts special emphasis on poly (2,5-benzimidazole) and epitomizes the on-going breath-taking progress and achievements on the fabrication of poly (2,5-benzimidazole) based membranes. The write-up describes the effect of blending, cross-linking, ionic liquids and incorporation organic/inorganic nano-fillers. In addition, incorporating other protonic dopants such as heteropoly acids into the chain of poly (2,5-benzimidazole) molecular skeleton is also overviewed. Moreover, the critical interpretation of different causes responsible for earlier degradation and their effect towards the fabrication of high temperature membrane electrode assembly are visualized herein.

• Highlights

• Current developments and existing challenges of ABPBI in PEMFC have been reviewed.

• PEM Modification and addition of protonic dopants has been discussed.

• Proton migration, permeability, stability and reliability are thoroughly illustrated.

• Different ABPBI-based membranes and their performance are comparatively analyzed.

中文翻译：

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聚（2,5-苯并咪唑）（ABPBI）作为潜在的PEM在HT-PEMFC中的应用的当前情况

在最近的二十年里，酸掺杂的聚苯并咪唑作为聚合物电解质膜（PEM）已被广泛认可并被设想为用于高温PEM燃料电池（HT-PEMFC）的“理想”质子传导材料。大部分研究和开发工作主要集中在聚（2,2´-间亚苯基-5,5´-联苯并咪唑）上，但是，它既不是易加工的产品，也不是各自家族的廉价产品。另一方面，在苯并咪唑家族的各个成员中，聚（2,5-苯并咪唑）具有独特的优势，因为它具有成本低廉，一步合成的过程，高掺杂程度以及良好的化学稳定性和热稳定性。 。近年来，这种材料已经在较早的研究中证明了其潜力。因此，这篇评论特别强调了poly（2，（5-苯并咪唑）代表了基于聚（2,5-苯并咪唑）膜的制造过程中令人叹为观止的进步和成就。文章描述了混合，交联，离子液体和掺入有机/无机纳米填料的效果。此外，还概述了将其他质子掺杂剂（例如杂多酸）掺入聚（2,5-苯并咪唑）分子骨架的链中。此外，本文显示了引起较早降解的不同原因的关键解释及其对高温膜电极组件制造的影响。离子液体和掺入有机/无机纳米填料。此外，还概述了将其他质子掺杂剂（例如杂多酸）掺入聚（2,5-苯并咪唑）分子骨架的链中。此外，本文显示了引起较早降解的不同原因的关键解释及其对高温膜电极组件制造的影响。离子液体和掺入有机/无机纳米填料。此外，还概述了将其他质子掺杂剂（例如杂多酸）掺入聚（2,5-苯并咪唑）分子骨架的链中。此外，本文显示了引起较早降解的不同原因的关键解释及其对高温膜电极组件制造的影响。

• 强调

• 回顾了PEMFC中ABPBI的当前发展和现有挑战。

• 已经讨论了PEM改性和质子掺杂剂的添加。

• 质子迁移，渗透性，稳定性和可靠性得到了充分说明。

• 对不同的基于ABPBI的膜及其性能进行了比较分析。