Xiao Yiming, Chen Haoran, Sun Ranxin, Zhang Lei, Xiang Jun, Cheng Penggao, Han Huaiyuan, Wang Songbo, Tang Na
Department of Chemical Engineering and Material Science, Tianjin University of Science & Technology, Tianjin 300457, China.
Tianjin Key Laboratory of Brine Chemical Engineering and Resource Eco-Utilization, Tianjin University of Science & Technology, Tianjin 300457, China.
Polymers (Basel). 2023 Jul 27;15(15):3197. doi: 10.3390/polym15153197.
Despite the outstanding proton conductivity of phosphoric acid (PA)-doped polybenzimidazole (PBI) membranes as high-temperature proton exchange membranes (HT-PEMs), chemical stability is a critical issue for the operation life of PEM fuel cells (PEMFCs). Herein, we introduced polymerized [HVIM]HPO ionic liquids (PIL) into an OPBI membrane to accelerate proton transfer and enhance the chemical stability of the membrane. Based on the regulation of the intrinsic viscosity of PIL, the entanglement between PIL chains and OPBI chains is enhanced to prevent the loss of PIL and the oxidative degradation of membrane materials. The PIL/OPBI membrane with the intrinsic viscosity of 2.34 dL·g (2.34-PIL/OPBI) exhibited the highest proton conductivity of 113.9 mS·cm at 180 °C, which is 3.5 times that of the original OPBI membrane. The 2.34-PIL/OPBI membrane exhibited the highest remaining weight of 92.1% under harsh conditions (3 wt% HO; 4 ppm Fe at 80 °C) for 96 h, and a much lower attenuation amplitude than the OPBI did in mechanical strength and proton conductivity performance. Our present work demonstrates a simple and effective method for blending PIL with OPBI to enhance the chemical durability of the PA-PBI membranes as HT-PEMs.
尽管磷酸（PA）掺杂的聚苯并咪唑（PBI）膜作为高温质子交换膜（HT-PEMs）具有出色的质子传导性，但化学稳定性是质子交换膜燃料电池（PEMFCs）使用寿命的关键问题。在此，我们将聚合的[HVIM]HPO离子液体（PIL）引入到OPBI膜中，以加速质子转移并提高膜的化学稳定性。基于对PIL特性粘度的调控，增强了PIL链与OPBI链之间的缠结，以防止PIL的流失和膜材料的氧化降解。特性粘度为2.34 dL·g的PIL/OPBI膜（2.34-PIL/OPBI）在180°C时表现出最高的质子传导率，为113.9 mS·cm，是原始OPBI膜的3.5倍。2.34-PIL/OPBI膜在苛刻条件（80°C下3 wt% HO；4 ppm Fe）下96小时后表现出最高的剩余重量，为92.1%，并且在机械强度和质子传导性能方面的衰减幅度远低于OPBI膜。我们目前的工作展示了一种将PIL与OPBI共混以提高PA-PBI膜作为HT-PEMs化学耐久性的简单有效方法。
