Cross-linked polyelectrolyte for direct methanol fuel cells applications based on a novel sulfonated cross-linker

• Published in: Journal of power sources Vol. 255; pp. 101 - 107
• Main Authors: Li, Mingyu, Zhang, Gang, Xu, Shuai, Zhao, Chengji, Han, Miaomiao, Zhang, Liyuan, Jiang, Hao, Liu, Zhongguo, Na, Hui
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2014; Elsevier
• Subjects: Applied sciences; Crosslinking; Direct energy conversion and energy accumulation; Direct methanol fuel cells; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Mechanical properties; Membranes; Methyl alcohol; Polyelectrolytes; Proton exchange membrane; Sulfonated cross-linker; Sulfonated poly(ether ether ketone); Sulfonic acid; Trimers; Sulfonated cross-linker; Direct methanol fuel cells; Proton exchange membrane; Sulfonated poly(ether ether ketone); Polyetheretherketone; Alcohol fuel cells; Ether copolymer; Crosslinking; Crosslink agent; Primary alcohol; Ketone copolymer; Sulfonate copolymer; Crosslinked copolymer; Polyelectrolyte; Sulfonate polymer; Cation exchange membrane; Application; Proton exchange; Methanol
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2013.12.116

A novel type of cross-linked proton exchange membrane of lower methanol permeation and high proton conductivity is prepared, based on a newly synthesized sulfonated cross-linker: carboxyl terminated benzimidazole trimer bearing sulfonic acid groups (s-BI). Compared to membranes cross-linked with non-sulfonated cross-linker (BI), SPEEK/s-BI-n membranes show higher IEC values and proton conductivities. Meanwhile, oxidative stability and mechanical property of SPEEK/s-BI-n membranes are obviously improved. Among SPEEK/s-BI-n membranes, SPEEK/s-BI-2 exhibits high proton conductivity, low swelling ratio (0.122 S cm−1 and 15.2% at 60 °C, respectively) and low methanol permeability coefficient. These results imply that the cross-linked membranes prepared with the newly sulfonated cross-linker are promising for the direct methanol fuel cells (DMFCs) application. •Cross-linker with proton conductive group was designed and synthesized.•A comparison between the sulfonated and non-sulfonated cross-linkers was made.•By using the sulfonated cross-linker, SPEEK has been successfully modified.•The result membranes showed low methanol crossover as well as high conductivity.•The oxidative stability of the result membranes was much improved also.