微波法制备钙钛矿结构的锂离子导体La0.56Li0.33TiO3（英文）

Microwave Treatment of Perovskite-type La0.56Li0.33TiO3 Lithium-ion Conductors

采用微波法制备了钙钛矿结构的锂离子导体材料La0.56Li0.33TiO3。将微波炉热处理过的粉末与管式炉热处理的粉末以不同比例混合,制备了La0.56Li0.33TiO3圆片。经过微波炉1 000℃热处理之后,所有的样品均结晶生成了四方相。与在管式炉中1 200℃烧结的样品相比,微波炉烧结得到的样品的总电导率和晶界电导率都更高。总电导率和晶界电导率的提高归因于微波烧结所产生的更适合的锂离子迁移通道以及更大的晶胞尺寸。所有样品的锂离子迁移数都接近于1,意味着所制备的样品均为离子导体。因此,微波烧结可用于在较低的温度制备锂电解质,克服了传统高温烧结的锂损失问题。

Perovskite-type lithium ion conductors, La0.56Li0.33TiO3, were prepared via microwave sintering. Precursor powders treated in a microwave oven were mixed with powders treated in a tube furnace at different ratios to make pellets of La0.56Li0.33TiO3. All the samples were subjected to thermal treatment at 1 000 ℃ in a microwave oven, thus crystallizing into the tetragonal phase. Compared to the samples sintered at 1 200 ℃ in a tube furnace, the samples sintered in the microwave oven exhibit greater total and grain-boundary conductivities. The enhanced total and grain-boundary conductivities are attributed to the better diffusion pathways created by the microwave sintering and the larger volume cell, compared to those of the non-microwave sintered samples. The transference number of lithium ions for all the sintered samples is close to 1, indicating that pure ionic conductors can be obtained.Microwave sintering could be used to prepare lithium electrolytes at lower temperatures without suffering from the lithium loss associated with conventional high-temperature sintering.