Preparation And Performance Research Of Lanthanum Chromites As Solid Oxide Electrolysis Cell Connector Material

In order to meet the requirements of the connector for solid oxide electrolysis cells (SOEC), the performance of lanthanum chromites and the hydrogen production efficiency of lanthanum chromites system were researched in this paper. We had an important comparison of the performance between lanthanum chromites and stainless steel material in this study,but also the quality of the hydrogen production efficiency were analysised.In the paper, we have prepared La1-xCaxCrO3powder by solid phase method. CaCO3and B4C adjusted the material composition. This paper considered the SOEC connector electrical conductivity, thermal expansion, mechanical strength and sealing function requirement.Based on CaCO3and B4C as sintering additives, this paper studied two kinds of sintering additives on the influence of crystal structure, sintering properties of LaCrO3, room temperature resistivity, high temperature resistance rate, the thermal expansion property and mechanical properties. The LaCrO3material doped with a small amount of two divalent alkaline earth metal ions (Ca2+, Sr2+), the conductive properties of the material can be greatly improved. Traces of ions B can effectively reduce the melting point of the material system, and bring out the impact of semiconductor electrical properties of alkali metals (Na+) ions from the material. Under high temperature and high humidity environment, the main factors influencing the LaCrO3connector conductivity performance were not perfectly clear. The influence of two kinds of sintering additives for LaCrO3products, especially the conductivity properties and the effect of thermal expansion performance were lacked of study.The above contents of study is the innovation point of this article.The LaCrO3connector doped with25mol%of CaCO3and0mol%of B4C has high performance. The powder of LaCrO3was produced SOEC connector by cold isostatic pressing sintering,but also its performance was compared with stainless steel material. The LaCrO3connector system has less resistance and higher stability than stainless steel system in high temperature between850℃and950℃. The LaCrO3connector has high chemical stability.Its resistance was keeped low level after oxygenized at800℃.But the surface reistance of the stainless steel increased explicitly after the same oxygenized process. The study found that LaCrO3connector than stainless steel connector has a higher average density of hydrogen production. The average hydrogen density of LaCrO3connector was about0.7ml/min. cm2, and that was about20%higher than stainless steel connector. LaCrO3is feasible as a SOEC connector,which has a good promotion prospects.