Preparation of Li4SiO4-xLi2O powders and pebbles for advanced tritium breeders

Li4SiO4 pebbles and Li2O pebbles have been considered as the potential candidates for tritium breeders. Li2O exhibits higher lithium density whereas worse lithium loss and hygroscopicity compared with Li4SiO4. It is anticipated to obtain an advanced breeder by combining Li4SiO4 with Li2O. The coexistence of Li4SiO4 and Li2O powders could not be obtained by solid state reaction using Li2CO3 as lithium source, while the biphasic Li4SiO4-xLi2O (x=0.1, 0.2, 0.3, 0.4) powders were prepared by sol-gel method in this experiment. Meanwhile, the biphasic Li4SiO4-xLi2O pebbles were fabricated by a wet method for the first time. The Li2O aggregated at the grain boundaries and promoted the grain growth of the Li4SiO4. The grain size and the crush load of the Li4SiO4-0.3Li2O pebbles reached 32.3 µm and 46.5 N, respectively.