两种不同阴极材料的固体氧化物燃料电池

研制了两种不同阴极材料的固体氧化物燃料电池Pt|YSZ|Ag和LSM |YSZ|Ag ,并测试了电池的开路电压与运行温度的变化关系。由实验可知 ,随着温度的升高电池的开路电压增大 ,它们的变化趋势不仅受温度的影响 ,还与阴极材料的结构、导电性能和反应机制有关。Pt|YSZ|Ag中电池Pt阴极具有电子导电性 ,电化学反应有效区域局限在三相界面 ,但Pt催化活性高 ,Pt|YSZ|Ag具有较好的中温输出性能。LSM |YSZ|Ag电池中LSM阴极具有电子 离子混合导电性 ,其电化学反应有效区域由三相界面扩展到两相界面 ,但在温度较低时LSM催化活性较低 ,在较高温度下才有高催化活性 ,因而LSM |YSZ|Ag在高温下输出性能明显提高

Solid oxide fuel cells with different cathode materials

Pt|YSZ|Ag and LSM|YSZ|Ag, the two types of fuel cells with different cathode materials were developed, and the relation between their open circuit voltage (OCV) and operating temperature was investigated. The experimental results show that the OCV of the cells increases with the temperature rising,and the OCV is also influenced by cathode structure, conductive property and reaction mechanism. The Pt cathode in Pt|YSZ|Ag fuel cell has electronic conductivity and its electrochemical reaction effective area is limited at the three phase boundary. The PT|YSZ|Ag fuel cell has good medium temperature output performance due to the high catalyzing activity of Pt. However, the LSM cathode in LSM|YSZ|Ag fuel cell has the electronicionic mixed conductivity and its electrochemical reaction effective area is extended to the two phase boundary. The output performance of LSM|YSZ|Ag fuel cell is improved obviously only at high temperature because the catalyzing activity of LSM is high at high temperature but is low at low temperature.