Development of efficient low-cost SOFC/SOEC protonic cathodes for reliable energy distribution

氧化物质子导体是低温固体氧化物燃料和电解电池（SOFC/SOECs）中很有前途的电解质。这是因为它们在低温下离子电导率相对较高。目前工作的主要目标是开发高效，低成本的SOFC/SOEC质子阴极，以实现可靠的能量分配。在过去的一年里，我在两个方面都取得了进步。第一阶段的主要任务是合成、评价和筛选新型质子阴极材料，同时采用带铸法制备三层半电池和单电池组件，以评估电极性能。通过固相反应和湿化学溶液法制备了一系列不同成分（BaPrCo2-xNbxO6-δ、BaLaCo1-xNbxO3-δ和BaLaCo2O6-δ，其中x =0-0.2）的富铌双、单钙钛矿，考察了铌含量对电极性能的影响。研究了复合材料的微观结构和电化学性能，并与母材（BaPrCo2O6-δ和BaLaCoO3-δ）进行了比较。为了彻底理解和验证预测正极材料质子和/或氧输运性质的模型，我们特别关注了母材料。通过同位素交换实验（18O和2D2O示踪剂）和飞行时间二次离子质谱深度分析对这两种材料的质子动力学的研究正在进行中，但由于目前的COVID-19大流行而被推迟。

Oxide proton conductors are promising electrolytes for low-temperature solid oxide fuel and Electrolysis cells (SOFC/SOECs). This is because of their relatively high ionic conductivities at low temperatures. The main objective of the current work is the development of efficient, low-cost SOFC/SOEC protonic cathodes for reliable energy distribution. During the past year, I have made progress in two front. Firstly, the synthesis, evaluation, and screening of new protonic cathode materials, which is the primary task of phase 1, conducted in parallel with the fabrication of tri-layered half and single-cell assemblies using tape casting to evaluate the electrode performances. A series of Co-rich double and single perovskites oxide with different compositions (BaPrCo2-xNbxO6-δ, BaLaCo1-xNbxO3-δ, and BaLaCo2O6-δ where ×=0-0.2) were prepared via solid-state reaction and wet chemical solution procedures to investigate the effect of Nb content on the electrode performance. The microstructure, as well as the electrochemical properties, are also investigated and compared with those of the parent materials (BaPrCo2O6-δ, and BaLaCoO3-δ). Particular attention has been focus on the parent material to thoroughly understand and validate models for predicting protonic and/or oxygen transport properties of the cathode material. Work on proton kinetics through the bulk of both materials by isotope exchange experiments (18O and 2D2O tracers) and Time-of-Flight Secondary Ion Mass Spectrometry depth profiling is ongoing, but has been delayed by the present COVID-19 pandemic.