摘要
以硝酸锂、硝酸锰为原料 ,柠檬酸作为络合剂 ,采用溶胶 凝胶法获得前驱体 ,然后将前驱体在空气气氛中焙烧制备了纳米LiMn2 O4 。采用DTA -TG对前驱体的热分解行为进行了研究 ,用XRD考察了合成产物的结构和纯度 ,用SEM对合成产物进行了形貌观察和尺寸测量 ,并采用氧化 还原返滴定方法测定了合成产物中锰的平均化合价。试验结果表明 ,在 3 0 0℃时已有明显的尖晶石LiMn2 O4 相出现 ;经 3 0 0℃预处理后产物的质量明显提高 ;合成产物的粒度和晶格常数随温度升高而增加 ;预处理后合成产物的形貌呈球形 ,颗粒尺寸在 3 0nm左右且分布均匀 ;锰的平均化合价为 3 .
Nano-LiMn_2O_4 spinel oxides has been prepared successfully by roasting precursor in the air atmosphere, while precursor was obtained by sol-gel techniques, with lithium nitrate and manganese nitrate as original material and citric acid as complexant. The thermal decomposition behavior of the precursor has been examined with the method of DTA-TG. The structure and purity of LiMn_2O_4 powder have been analyzed by means of XRD. The morphology of it also has been observed and grain size has been measured by SEM. The mean valency of manganese in LiMn_2O_4 has been determined by redox titration method. Results show that there're some obvious spinel structure of LiMn_2O_4 at 300 ℃. And the quality of LiMn_2O_4 can be remarkably improved after being pretreated at 300 ℃. The grain size and lattice constant tend to increase with the increase of temperature. After pretreatment, LiMn_2O_4 is in the form of sphericit, distributing evenly with the average grain size of 30 nm. The mean valency of manganese is 3.498, which is very close to the theoretical value.
出处
《矿冶工程》
CAS
CSCD
北大核心
2005年第1期72-74,共3页
Mining and Metallurgical Engineering
基金
黑龙江十五攻关项目 (编号 :GC0 1A2 2 0 1 )
