The Synthesis And Characterization Of Lanthanum Germanate-based As Ceramic Electrolyte

With the development of society, the clean and efficient energy has achievedconsiderable worldwide interest due to the people’s new demands for energy. Solidoxide fuel cells (SOFCs) as a clean and efficient energy have gained people’sattention, and the electrolyte has become a research hotspot because whichdetermines the energy conversion efficiency of SOFCs. Recently, the lanthanumgermanate-based ceramic electrolyte have been the potential choose of electrolyteowing to relatively low working temperature, good chemical stability and highenergy efficiency.In this case, we investigated the proper doped lanthanum germanate-basedceramic by a facile molten-salt synthesis method using NaCl as a eutectic salt. Wehave successfully synthesized the apatite-type La9.37Ge5.9Co0.1O26,La9.4Ge5.9Mg0.1O26, La9.4Ge5.9Ni0.1O26, La9.38Ge5.9Mn0.1O26, La9.4Ge5.9Cu0.1O26andLa9.4Ge5.8Co0.2O26, La9.47Ge5.8Mg0.2O26, La9.47Ge5.8Ni0.2O26, La9.42Ge5.8Mn0.2O26andLa9.47Ge5.8Cu0.2O26under the different doping content and sintering time. Here, wehave studied how the sintering time affects the growth process of samples, and thebest time of8h has been determined. The synthesized samples are homogeneous,nano-size, and well crystallized particles with the clean apatite-type phase. Thedense pellets of La9.37Ge5.9Co0.1O26, La9.47Ge5.8Mg0.2O26and La9.47Ge5.8Cu0.2O26have been sintered for once or two times at1100°C, which conductivity values arereached10-2magnitude at850°C and all display the higher conductivity than theundoped La9.33Ge6O26. Electrical tests showed that the conductivity of the samplesintered for once at1100°C is better than others. In this case,La9.37Ge5.9Co0.1O26andLa9.47Ge5.8Cu0.2O26display the similar conductivity values and all display the higherconductivity than La9.47Ge5.8Mg0.2O26.