Preparation and Evaluation of Proton Conductive Membranes for Medium Temperature Fuel Cells

中温燃料电池质子传导膜的制备与评价

基本信息

批准号：
14550669
负责人：
MATSUDA Atsunori
金额：
$ 2.3万
依托单位：
Toyohashi University of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

Solid state proton-conductive membranes with high conductivity in the medium temperature range (100-200ーC) even under low humidity are highly required as the electrolytes for PEFCs. Since the operation of PEFCs in the medium temperature range improves the utilization of total electric power generated in the cells. and depresses the poisoning of Pt catalysts with CO in the fuel gases. In addition, working of PEFCs under low humidity permits to reduce the weight and volume of humidifiers. In the present work, proton conducting membranes based on sol-gel derived phosphosilicate (P_2O_5-SiO_2) gel have been fabricated for the application to medium temperature fuel cells as an electrolyte.Two types of proton conductive membranes, which show high conductivities even at medium temperatures with low humidity, have been successfully prepared. One is a composite sheet composed of phosphosilicate gel powder and organic polymer such as heat resistant polyimide. The other is a hybrid sheet in which inorganic and organic components derived from an organosilane such as 3-Glycidoxypropyltrimethoxysilane and phosphoric acid are covalently bonded.Fuel cells using a composite sheet composed of phosphosilicate (P_2O_5-SiO_2, P/Si=1 in mole ratio) gel powder and polyimide operated up to 150ーC under a relatively low water vapor, pressure. Maximum power density of the fuel cell increased with increasing operation temperature and was 28 mW cm^<-2> at 150 ℃ and 18 %RH. With respect to the hybrid type, fuel cells using a hybrid sheet derived from 3-Glycidoxypropyltrimethoxysilane and phosphoric, acid also continuously operated at 130 ℃.It was found that the addition of tin and tantalum as well as aluminum improved the chemical durability of phosphosilicate gels by depressing the leaching of phosphoric acid from the gels. At the same time, the improvement of durability of the gels resulted in a decrease in the proton conductivity.

由于PEFC在中温范围内运行提高了总电的利用率，因此非常需要在中温范围（100-200℃）甚至在低湿度下也具有高电导率的固态质子导电膜作为PEFC的电解质。此外，PEFC 在低湿度下工作还可以减少加湿器的重量和体积。目前的工作，基于溶胶-凝胶衍生的磷硅酸盐（P_2O_5-SiO_2）凝胶的质子传导膜已被制备用于中温燃料电池作为电解质。两种类型的质子传导膜，即使在中温下也表现出高电导率一种是由磷硅酸盐凝胶粉末和有机聚合物（例如耐热聚酰亚胺）组成的复合片材，另一种是无机聚合物的混合片材。源自有机硅烷（如3-缩水甘油氧基丙基三甲氧基硅烷）和磷酸的有机成分以共价键结合。使用由磷硅酸盐（P_2O_5-SiO_2，摩尔比P/Si=1）凝胶粉末和聚酰亚胺组成的复合片的燃料电池可在高达150℃的温度下运行-C在相对较低的水蒸气压力下，燃料电池的最大功率密度随着工作温度的升高而增加，为28。在150℃和18％RH下的mW cm^ -2 对于混合型，使用源自3-缩水甘油氧基丙基三甲氧基硅烷和磷酸的混合片的燃料电池也在130℃下连续运行。锡、钽以及铝的添加通过抑制磷酸从凝胶中的浸出而提高了磷硅酸盐凝胶的化学耐久性。同时，凝胶耐久性的提高导致质子电导率的降低。