摘要
采用高温固相法制备了4种高纯度晶相组成的LixZryOz三元化合物,研究了焙烧温度、时间、反应物的种类和初始反应物物质的量比对产物组成的影响,进一步用XRD、SEM及BET分析方法对产物的晶相结构、表面形貌及比表面积进行了表征。实验结果表明,Li2CO3与ZrO2在适当条件下可以合成得到单斜相Li2ZrO3;以LiOH替代Li2CO3,在适当条件下可以分别合成得到四方相Li2ZrO3和三斜/单斜相Li6Zr2O7;进一步以Zr(NO3)4·5H2O代替ZrO2,可将单斜相Li6Zr2O7的制备时间由96h缩短至24h。SEM照片显示产物硬团聚明显,粒径分布在1~10μm间,BET分析表明样品比表面积处于1.0~9.0m2·g-1间分布,反应过程中锂的过量以及长时间高温焙烧是引起产物粒径长大和产生硬团聚的主要原因。
Four kinds of crystalline phase LixZryOz compounds with high purity are synthesized by high-temperature solid-state reaction, and the influences of different reagents, calcination temperatures and calcination time on the LixZryOz synthesis are also studied systematically, XRD, SEM and BET are employed to analyse the crystal phase structures, morphologies and surface area of the final products respectively. The experimental results indicate that monoclinic phase Li2ZrO3 could be produced with Li2CO3 and commercial ZrO2 at suitable conditions, tetragonal phase Li2ZrO3 and triclinic/monoclinic phase Li6Zr2O7 with LiOH and ZrO2; Further, with the substitution of ZrO2 by Zr(NO3)4·5H2O, the re-crystallization time for monoclinic phase Li6Zr2O7 is remarkably shortened from 96 h to 24 h. SEM images show that the particle radii range within 1-10 μm with serious agglomeration; The BET analysis shows that the surface area of products distributes between 1.0 m2·g^-1 and 9.0 m2·g^-1. The superfluous lithium in initial reactants and high-temperature calcination resulted in the larger particle radio and serious agglomeration of the final products.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2009年第7期1221-1226,共6页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.20576031&20706014)
教育部科学研究重点项目(No.108144)
上海市科委纳米专项(No.0852nm02100)资助项目
关键词
锆酸锂
高纯度晶相
高温固相法
lithium zirconate
high-purity crystal-phase
high-temperature solid-state reaction