A comparative study on the properties of Li2TiO3 powders and pebbles fabricated by different routes

Abstract

Lithium titanate (Li2TiO3) is one of the promising candidate breeders for tritium self-sufficiency of deuterium(D)-tritium(T) fusion reaction. The differences in powder synthesis methods have a great impact on the properties of Li2TiO3 powders and the performance of Li2TiO3 ceramic pebbles. In this study, the Li2TiO3 powders were successfully synthesized by hydrothermal method and solid-state method, and then the pebbles were fabricated by the agar-based wet method. The mechanism of hydrothermal synthesis of Li2TiO3 powder was discussed. For the hydrothermal method, the Li2TiO3 powder with single phase can be obtained when the rate of Li/Ti = 2.4, and the powder presented two different morphology, which involved two reaction mechanisms, including in-situ phase transformation mechanism and dissolution-precipitation mechanism, the phase transformation from α-Li2TiO3 to β-Li2TiO3 accomplished at 400°C, which is lower than that of 750°C for solid-state method. Li2TiO3 pebbles prepared by the hydrothermal-wet method had a uniform pore distribution, an optimal grain size of 2.7 μm, a crushing load of 58.6 N, and relative density of 90.2%, respectively. In comparison, pebbles prepared by the solid-state-wet method also had better mechanical properties, which the crushing load and relative density were 53.9 N and 86.9% respectively under the optimal fabrication conditions.