物理化学学报 >> 2021, Vol. 37 >> Issue (9): 2009049.doi: 10.3866/PKU.WHXB202009049

所属专题: 燃料电池

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催化层掺杂共价有机框架材料提升高温聚电解质膜燃料电池性能

田立亮1, 张玮琦1, 解政1, 彭凯1, 马强1, 徐谦1, Pasupathi Sivakumar2, 苏华能1,*()   

  1. 1 江苏大学,能源研究院,江苏 镇江 212013
    2 西开普大学,南非先进材料化学研究所,开普敦 7535,南非
  • 收稿日期:2020-09-15 录用日期:2020-10-18 发布日期:2020-10-23
  • 通讯作者: 苏华能 E-mail:suhuaneng@ujs.edu.cn
  • 基金资助:
    国家重点研发计划(2018YFE0121200);国家自然科学基金(21676126);江苏高校优势学科建设工程项目(PAPD)

Enhanced Performance and Durability of High-Temperature Polymer Electrolyte Membrane Fuel Cell by Incorporating Covalent Organic Framework into Catalyst Layer

Liliang Tian1, Weiqi Zhang1, Zheng Xie1, Kai Peng1, Qiang Ma1, Qian Xu1, Sivakumar Pasupathi2, Huaneng Su1,*()   

  1. 1 Institute for Energy Research, Jiangsu University, Zhenjiang, 212013, Jiangsu Province, China
    2 South African Institute for Advanced Materials Chemistry, University of the Western Cape, Bellville 7535, South Africa
  • Received:2020-09-15 Accepted:2020-10-18 Published:2020-10-23
  • Contact: Huaneng Su E-mail:suhuaneng@ujs.edu.cn
  • About author:Huaneng Su, Email: suhuaneng@ujs.edu.cn; Tel.: +86-511-88799500
  • Supported by:
    the National Key Research and Development Program of China(2018YFE0121200);the National Natural Science Foundation of China(21676126);the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions

摘要:

基于磷酸掺杂聚苯并咪唑(PBI)高温聚电解质膜燃料电池(HT-PEMFC)具有环境耐受性好、水热管理简单等优点,被认为是未来PEMFC的发展方向。而减少其运行过程中磷酸电解质的流失是维持HT-PEMFC性能稳定性的关键因素。在本工作中,我们提出在电极催化层中引入一种席夫碱型(SNW-1)共价有机框架(COF)材料的策略来减少膜电极(MEA)中的磷酸流失,从而增强HT-PEMFC的耐久性。由于该COF材料中大量与磷酸分子匹配的微孔和特定的官能团结构,使其不仅拥有优越的磷酸保留能力,而且具有良好的质子传导能力,因此该HT-PEMFC在电池加速老化测试中展现出很好的稳定性。此外,发现在催化层中引入5%–10%的COF材料,可有效提高电极电化学活性面积并降低电池的欧姆内阻和电荷转移电阻,从而可进一步提高HT-PEMFC放电性能。在150 ℃、氢/空和常压操作条件下,工作电压0.6 V时催化层中添加10% COF材料的电池电流密度达到0.361 A·cm-2,较常规电池性能提升30%左右。该工作说明在催化层中掺杂适量COF材料有希望成为提升HT-PEMFC性能和耐久性的一种有效策略。

关键词: 高温聚电解质膜燃料电池, 膜电极, 共架有机框架, 磷酸流失, 稳定性

Abstract:

Proton exchange membrane fuel cells (PEMFCs) are considered one of the most promising technologies for efficient power generation in the 21st century. However, several challenges for the PEMFC power technology are associated with low operating temperature, such as complex water management and strict fuel purification. PEMFC operating at high temperature (HT, 100–200 ℃) has in recent years been recognized as a promising solution to meet these technical challenges. At present, HT-PEMFC based on phosphoric acid (PA)-doped polybenzimidazole (PBI) is considered to be the trend of PEMFC future development due to its good environmental tolerance and simplified water/ thermal management. In this HT-PEMFC system, the proton transfer in both catalyst layer (CL) and membrane relies on liquid PA. Thus, a proper amount of PA is required to impregnate the membrane and the CL in order to achieve good proton conductivities in an HT-PEMFC system. Therefore, reducing the loss of PA electrolyte in the membrane electrode assembly (MEA) is crucial to maintaining the good durability of HT-PEMFC. In this work, a Schiff base networks (SNW)-type covalent organic framework (COF) material is proposed as the CL additive to enhance the durability of HT-PEMFC. The well-defined porous structure and tailored functional groups endow the proposed COF network with not only excellent PA retention capacity but also good proton transfer ability, thus leading to the superior durability of the HT-PEMFC in an accelerated stress test (AST). After 100 h operation at heavy load (0.2 V) and high flow rate of air purge, the accumulative PA loss of the COF-based MEA was ~4.03 mg, which is almost an order of magnitude lower than that of the conventional MEA (~13.02 mg), consequently leading to a much lower degradation rate of current density (~0.304 mA·cm-2·h-1) than that of the conventional MEA (~1.01 mA·cm-2·h-1). Moreover, it was found that the electrode incorporating a proper amount (5%–10%, mass fraction) of the COF material possessed a higher electrochemical surface area (ECSA) and lower ohmic and charge transfer resistances, which further improved the performance of the HT-PEMFC. At the usual operating voltage of 0.6 V, the current density of the MEA containing 10% COF was up to 0.361 A·cm-2, which is ~30% higher than that of the conventional MEA at 150 ℃, H2/Air and ambient pressure. These results indicate that incorporating COF materials into CL is a promising strategy to enhance the performance and durability of HT-PEMFC.

Key words: High temperature polymer electrolyte fuel cell, Membrane electrode assembly, Covalent organic framework, Phosphoric acid leakage, Durability

MSC2000: 

  • O646