【摘要】 铬酸镧(LaCrO3)材料具有良好的高温化学稳定性与物理稳定性,被认为是理想的高温电解制氢的连接体隔板材料,然而其高温下电导性能的主要影响因素仍有待研究。采用固相法合成掺杂CaCO3和B4C铬酸镧粉体,并研究了掺杂量对铬酸镧陶瓷的烧结性能、电阻率的影响。应用X射线衍射(XRD)、扫描电子显微镜(SEM)、四探针法和排水法分析了铬酸镧连接体的结构、微观形貌、晶相组成、电阻率以及密度。研究表明:加入CaCO3,B4C能够促进晶粒细化,但B4C的加入不利于铬酸镧陶瓷致密化烧结。加入CaCO3能降低材料电阻率,B4C的加入可能改变晶界电阻,从而对陶瓷的电阻率形成影响。CaCO3=20%,B4C=0.1%(摩尔分数)配比的铬酸镧作为连接体材料,高温下具有较低且稳定的电阻率。更多还原

【Abstract】 The LaCrO3 was considered as an ideal interconnector of solid oxide electrolysis cell because of its chemical and physical stability at high temperature.However,the main effect of its conductivity performance at high temperature was unknown.The powders of LaCrO3 doped with CaCO3 and B4C were prepared by the solid state reaction,and the affect of doping amount on the sintering properties and resistivity was studied.The structure,micrographs,phase composition,resistivity and density were analyzed by XRD,SEM,four-probe measurement and drainage method.The research showed that the addition of CaCO3 and B4C could promote grain refinement,but the addition of B4C was not conducive to densification of sintered for LaCrO3.Moreover,the CaCO3 could reduce the electrical resistivity,and B4C might change the grain boundary resistance,which affected on resistivity of ceramic.The LaCrO3 doped with CaCO3=20 mol% and B4C=0.1 mol% as the interconnector had more lower and stable resistivity at high temperature.更多还原