摘要
以醋酸锂、醋酸锰为原料，尿素为燃料，用液相燃烧合成方法制备尖晶石型LiMn2O4物质，考察了焙烧温度（300-800℃焙烧5h）对产物的组成结构、晶粒大小及电化学性能的影响。实验结果表明，未焙烧产物中主晶相为LiMn2O4及少量Mn2O3，但在300-800℃焙烧5h后都可得到单相的LiMn2O4粉体材料，焙烧温度为900℃时，LiMn2O4部分分解为Mn3O4；产物颗粒随焙烧温度升高而长大，≤600℃时，产物颗粒〈100nm，≥700℃时产物颗粒〉100nm，可观察到LiMn2O4的特征八面体结构；在焙烧温度800℃以下，产物的电化学性能随焙烧温度的升高而增加。当电流密度为C/3时，焙烧温度为800℃的首次放电容量为105mAh／g，但循环性能较差，30次循环后仅剩83％。
Influence of calcination temperatures（300-800℃） to structures and electrochemical performances of spinel LiMn2O4 powders, prepared by solution combusition method using lithium and manganese acetate as starting materials and urea as fuel, with the molar ratio of Li：Mn： urea= 1：2：5 was studied. The results indicated that the main phase of LiMn2O4 and a little impurity phase of Mn2O3 in the product were obtained when not calcination, and high pure LiMn2O4 powders were gained when calcination at 300-800℃ for 5h, but when calcination at 900℃, LiMn2O4 decomposed to Mn3O4 partly. The grain sizes increased with the increment of calcination temperatures. The electrochemical performances increased with the increment of calcination temperatures between 300℃ to 800℃, and the highest discharge sepcific capacitance reached as high as 105mAh/g at 800℃ for 5h, but remained only 83% after 30 cycles.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2007年第A04期1405-1407,共3页
Journal of Functional Materials
基金
基金项目：国家自然科学基金资助项目（90610011）
云南省自然科学基金资助项目（2005C0078M：2006E0091M）
