Low-temperature sintering of Li4SiO4 spheres with high crushing load using mesoporous silica as Si sources

Abstract

Li4SiO4 has been widely studied as tritium breeder and high temperature CO2 capture material. Tritium breeding rate and CO2 adsorption capacity are closely related to lithium content and microstructure. Since high sintering temperatures result in grain coarsening and lithium sublimation, it is a great challenge to prepare Li4SiO4 ceramics with a satisfactory mechanical strength at low sintering temperature. In this work, mesoporous silica was used as Si source to prepare Li4SiO4 spheres. The mesoporous structure might provide more reaction sites for lithium ions, thereby facilitating the reaction between LiOH and mesoporous silica. The sintering temperature of Li4SiO4 spheres was greatly reduced by using mesoporous silica as Si source. The Li4SiO4 spheres with a homogenous fine-grained microstructure (the average grain size of 2.2 ?m) and high crushing load (41.65N) could be obtained at 675?C.