Synthesis, CO2 absorption property and densification of Li4SiO4 powder by glycine-nitrate solution combustion method and its comparison with solid state method

Abstract

Phase pure Lithium orthosilicate (Li4SiO4) nanopowder was synthesized by solution combustion method using glycine as the fuel and silicic acid as a silica source. The effect of the fuel-to-oxidizer ratio (Φe) (0.6–1.0) in the combustion process and phase evolution was studied. We found that by controlling the fuel-to-oxidizer ratio of the starting solution phase purity can be achieved at 700 °C. Li4SiO4 powder was also prepared by solid state method and phase purity was achieved at 800 °C. The surface area, powder morphology, sintering behavior and CO2 capture properties of the Li4SiO4 were investigated. The powder synthesized by solution combustion route showed higher surface area, sinterability and CO2 absorption capacity compared to the solid state route powder. It could be attributed to the nanostructured morphology of the particles. The grain size in the sintered sample could be kept well below 5 μm. The current report provides a novel method to fabricate lithium orthosilicate, and shows promise for application as high temperature CO2 absorption as well as solid breeder in fusion reactor.