【作者】 刘杰； 刘贵阳； 张国伟； 王宝森； 崔茜； 郭俊明；

【Author】 LIU Jie LIU Gui-yang ZHANG Guo-wei WANG Bao-sen CUI Qian GUO Jun-ming (College of Science,Honghe University,Mengzi 661100,China)

【机构】 红河学院理学院；

【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%。更多还原

【Abstract】 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 elecU’ochemical 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.更多还原