Sintering Properties of Apatite-Type Lanthanum Silicate Electrolytes

The sintering properties of appetite-type lanthanum silicate La10Si6O27prepared by sol-gel process were studied. The precursor powder was sintered by one-step sintering (OSS) process, two-step sintering (TSS) process and spark-plasma sintering (SPS) process. The phase structure, microstructure, relative density, thermal expansion properties, electrochemical properties of the samples were investigated by means of the techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), Archimedes method, dilatometer, and AC impedance spectroscopy. The experimental results show that the samples sintered by SPS process can decrease the sintering temperature, shorten the sintering time, increase the density, and reduce the particle size. The appetite-type lanthanum silicate La10Si6O27 sintered by SPS process shows better sintering properties than of sintered by OSS process and TSS process, which can beneficial to the thermal expansion properties and conductivity.