双钙钛矿型电极材料在中低温固体氧化物燃料电池中的应用

Double Perovskite Material as An Electrode for Intermediate-Temperature Solid Oxide Fuel Cells Application

近年来固体氧化物燃料电池（SOFCs）由于高效率（高达80%）、环境友好和燃料适用广泛等优点得到了人们的广泛关注。但是,由于其通常需要1000℃以上的工作温度才能达到所需的性能,其商业化及产业化应用受到了严重制约。中低温固体氧化物燃料电池（IT-SOFCs）的研发是固体氧化物燃料电池进一步商业化的必然趋势。降低工作温度（从高温1000℃以上降低至中低温500-800℃）可提高燃料电池的稳定性、降低电池运行成本、增加系统材料可选性,而研发出中低温下性能优异的燃料电池电极材料是实现固体氧化物燃料电池中低温化的关键。作为混合离子-电子导体材料之一,双钙钛矿型氧化物材料可以成功地将燃料反应活性区域从传统的电极-电解质-反应气体三相界面扩展到整个电极的表面,进而降低材料的极化电阻并大大提高电极在中低温条件下对氧的催化活性。由于双钙钛矿结构材料良好的氧离子传输能力、较低的热膨胀系数、优异的催化活性、较强的抗硫中毒和抗碳沉积能力,近年来成为非常有发展潜力的SOFCs电极材料。本文综述双钙钛矿型氧化物材料作为SOFCs电极材料的最新研究进展,指出目前双钙钛矿电极材料存在的主要问题,并提出SOFCs未来的主要研究发展方向。

Solid oxide fuel cells（ SOFCs） have attracted considerable attention because of their high energy conversion efficiency（ reach up to 80%）, low emission of pollutants, and excellent fuel flexibility.Conventional SOFCs need to be operated at high temperature typically at - 1000 ℃ to obtain the required performance. This high operating temperature leads to the degradation of fuel cell performance,interfacial reactions among the components,and limited choice of materials. Therefore,intermediate temperature solid oxide fuel cell（ IT-SOFCs） w ould be a development trend for the next generation of SOFCs which could becommercialized in the future. Low ing the operating temperature from traditional 1000 ℃ to 500 - 800 ℃ or even low er not only significantly prolongs the lifetime of materials and reduces the SOFCs system costs,but also provides a broader range for material selection. Therefore,it is necessary to develop a new electrode material with high electrochemical activity in intermediate temperature range to improve electrochemical performance. As one of the mixed ionic-electronic conductors（ MIECs）,the reaction sites of double perovskite materials extend the active sites from the three phase boundary to the entire exposed surface,which affords low polarization resistance and high performance at intermediate operating temperature. Meanw hile,due to the high ability of transporting oxygen ions,the low thermal expansion coefficient,good catalytic activity and high tolerance to sulfur poisoning and strong resistance against carbon deposition, the double-perovskite oxide becomes a promising electrode material for the IT-SOFCs. This review focuses on the structure stability,electronic and ionic conductivity as well as catalytic activity of perovskite materials. The main concerns about current double perovskite based electrode materials are summarized and the main future research directions are proposed.