La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)钙钛矿结构固体氧化物燃料电池阴极材料的制备与性能研究

A Study of Preparation and Cathode Properties in La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)Provskite Materials for Solid Fuel Cells

双碳目标背景下,新能源材料与技术开发是绿色能源发展面临的主要课题之一,中低温下Fe基钙钛矿结构阴极材料是固体燃料电池阴极材料的潜在热点材料。利用固相反应法,以La_(0.5)Ba_(0.5)FeO_(3)为基质材料,Ca离子以掺杂方式替换部分Ba原子,实现Ba、Ca双离子比例调节,合成了La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)(x=0.1,0.25,0.4,0.5)系列阴极材料,对其相结构、热膨胀行为、导电性、电催化活性及电池性能进行了系统研究。样品整体为立方钙钛矿结构。La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)与电解质的热膨胀系数具有良好的热匹配性,La_(0.5)Ba_(0.1)Ca_(0.4)FeO_(3)呈现最大电导率187.7 S/cm。Ca元素掺杂大大提高了La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)作为电极的电池输出功率密度,且输出功率密度较为稳定,800℃时峰值功率密度达到595 mW/cm^(2)。Ca离子的掺杂对La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)阴极材料性能起到促进作用,是中温固体燃料电池阴极候选材料。

Under conditionof the dual-carbon target background,the development of new energy materials and technologies is one of the main issues.Fe-based perovskite cathode materials are potential hot materials for cathode materials of solid fuel cells at medium and low temperatures.Taking La_(0.5)Ba_(0.5)FeO_(3)as matrix materials,Ca ion is doped by replacing some Ba atoms to make the ratio of Ba and Ca double ions adjusted,and a series of cathode materials La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)(x=0.1,0.25,0.4,0.5)are synthesized by a solid state reaction method.And the phase structure,thermal expansion behavior,conductivity,electrocatalytic activity and battery electrode performance are systematically studied.The overall structure of the sample is of cubic perovskite.La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)is characterized by a good thermal compatibility with the thermal expansion coefficient of electrolyte.The maximum conductivity of La_(0.5)Ba_(0.1)Ca_(0.4)FeO_(3)is 187.7 S/cm.The Ca doping is to greatly improve the output power density of cell with La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)as electrode to make the output power density stable relatively,and the peak power density reaches 595 mW/cm^(2)at 800℃.The doping of Ca ion can promote the performance of La_(0.5)Ba_(0.5-x)Ca_(x)FeO_(3)cathode material,and such doping material is a good candidate material for intermediate temperature solid oxide fuel cell(IT-SoFc)cathode.