【摘要】 具有钙钛矿结构的固态电解质钛酸镧锂(Li_3xLa_2/3-xTiO₃, LLTO)因在室温下具有较高的电导率,是目前固态电解质领域重要的研究热点。探究可以制备出含杂相少、微观应变小、粒度分布均匀适宜、尺寸均一、形貌优良的LLTO固态电解质粉末的条件十分必要。通过水热法在900℃及1 050℃两种不同煅烧保温温度下制备固态电解质LLTO,研究了在这两种不同保温条件下制备的LLTO的合成情况、形貌、粒度、微观应变等。结果表明在900℃和1 050℃的保温温度下都能成功合成LLTO,但两种保温温度下合成的粉末均为不规则形状颗粒,且均存在一定程度的团聚;从最终合成的物质的相组成来看,900℃保温条件下合成的LLTO含杂相更少。结合激光粒度仪测量的颗粒尺寸与X射线衍射测量的晶粒尺寸,从宏观的激光粒度测量看,在900℃保温2 h,合成的粉末粒径分布在1.7～3μm和33～57μm范围,在1 050℃保温2 h,合成的粉末粒径分布在2.5～7μm和24～48μm;而利用X射线衍射从微观角度分析,平均晶粒尺寸分别为217.3 nm（900℃）、314.3 nm（1 050℃）,与激光粒度仪分析的平均颗粒尺寸存在差异;从制备的颗粒的微观应变来看,在两种保温温度下均存在微观应变导致的晶格参数变化,在更高的保温温度（1 050℃）下,微观应变更大。综合实验结果可知,煅烧保温温度900℃是制备LLTO粉末更适宜的保温条件。更多还原

【Abstract】 The solid electrolyte lanthanum titanate lithium(LLTO) with perovskite structure is an important research hotspot in the field of solid electrolyte because of its high conductivity at room temperature. It is necessary to study the conditions for the preparation of LLTO powder with less heterophase, small microstrain, uniform and suitable particle size distribution, uniform size and fine morphology. In this paper, the solid electrolyte LLTO was prepared by hydrothermal method under two different heat preservation temperatures(900 ℃ and 1 050 ℃)． The synthesis,morphology, particle size, microstrain and other conditions of LLTO prepared under these two different heat preservation conditions were studied.The results show that the LLTO can be successfully synthesized at 900 ℃ and 1 050 ℃, but the powders synthesized at the two temperatures are both irregular particles and have a certain degree of agglomeration. From the point of view of the phase composition, LLTO synthesized under the thermal insulation condition of 900 ℃ contains less heterophases. Considering particle size from laser granulometer and grain size from X ray diffraction, from macro-perspective of laser granulometer, powder particle size distribution was in 1.7—3 μm and 33—57 μm at 900 ℃ for 2 h and in2.5—7 μm and 24—48 μm at 1 050 ℃ for 2 h while the average grain size analysis from the microscopic view by XRD were 217.3 nm(900 ℃),314.3 nm(1 050 ℃)． From the perspective of the microstrain of the prepared particles, microstrain has existed to lead to the change of lattice parameters at both temperatures, and the microstrain was larger at the higher heat preservation temperature(1 050 ℃)． Based on the experimental results, when the heat preservation temperature is 900 ℃, it is more suitable for the preparation of LLTO powder.更多还原