直接甲醇燃料电池溶胶-凝胶流动相的制备及性能

以硅酸钠或硅酸乙酯与甲醇、硫酸为原料,采用改性溶胶-凝胶法制备了溶胶-凝胶流动相.以SEM观察流动相的形貌,测定了其甲醇渗漏和电化学性能,并研究了流动相的制备温度及组分对成胶速率及甲醇渗漏的影响.结果表明,溶胶-凝胶流动相具有多孔结构,改变了甲醇的传质途径和传质机理,与相同浓度的甲醇和硫酸液相流动相相比,渗漏率下降了90%以上,流动相制备的最佳温度为30℃,流动相中SiO2最佳质量分数为4%.

Preparation and Performance of the Sol-Gel Flux Phase of Direct Methanol Fuel Cell

The sol-gel flux phase of direct methanol fuel cell was prepared by the modified sol-gel method by using Na2SiO3 or Si（OC2H5）4 and methanol,sulfuric acid.The sol-gel flux phase was characterized by SEM.The methanol permeability,electrochemical characteristics of the sol-gel flux phase,the influence of the preparing temperature and the composition of the sol-gel flux phase on the gel-formed rate and methanol permeability were investigated,which showed that the sol-gel flux phase had porous structure that changed the mass transfer mechanism and process of methanol.The methanol permeability of the sol-gel flux phase decreased more than 90%,compared with the liquid flux phase of the same concentration of CH3OH and H2SO4.Therefore,it can be concluded that the best preparing temperature of the sol-gel flux phase is 30 ℃ and the best mass concentration of SiO2 in the sol-gel flux phase is 4%.