Cathode catalyst layers （CLs） with varying ionomer （Nation） contents were prepared and the direct methanol fuel cell structure and catalytic behavior were investigated as a function of ionomer content. CL roughnes...Cathode catalyst layers （CLs） with varying ionomer （Nation） contents were prepared and the direct methanol fuel cell structure and catalytic behavior were investigated as a function of ionomer content. CL roughness and thickness increased with increasing Nation content. Contact angle measurements determined that CL hydrophilicity also increased as a function of Nation content. Poor bonding between the CL, microporous layer, and the proton exchange membrane was obtained when the ionomer content was too low. The electrochemical surface areas （ESAs） were found to increase with increasing Nation content before reaching an asymptote at elevated loading levels. However, upon increasing the ionomer content above 30 wt.%, the water and oxygen mass transler properties were difficult to control. Considering the above conditions, N30 （：30 wt.% Nation） was found to be the optimal level to effectively extend the three-phase boundaries and enhance cell performance.展开更多
基金supported by the National Basic Research Program of China(973 Program,2012CB932800)the National Natural Science Foundationof China(21433003,21373199)the Science&Technology Research Programs of Jilin Province(20150101066JC,20160622037JC)
文摘Cathode catalyst layers （CLs） with varying ionomer （Nation） contents were prepared and the direct methanol fuel cell structure and catalytic behavior were investigated as a function of ionomer content. CL roughness and thickness increased with increasing Nation content. Contact angle measurements determined that CL hydrophilicity also increased as a function of Nation content. Poor bonding between the CL, microporous layer, and the proton exchange membrane was obtained when the ionomer content was too low. The electrochemical surface areas （ESAs） were found to increase with increasing Nation content before reaching an asymptote at elevated loading levels. However, upon increasing the ionomer content above 30 wt.%, the water and oxygen mass transler properties were difficult to control. Considering the above conditions, N30 （：30 wt.% Nation） was found to be the optimal level to effectively extend the three-phase boundaries and enhance cell performance.
