氧化淀粉为碳源冷冻干燥法制备LiFePO_4/C的研究  

Study on performance of the LiFePO_4/C prepared by freeze drying method using oxidized starch as carbon source

作　　者：李庆余[1] 张初华 王红强[1] 王新宇[1,2] 黄有国[1] 汪艳芳[1] 

机构地区：[1]广西师范大学化学化工学院,广西桂林541004 [2]中南大学冶金科学与工程学院,湖南长沙410083

出　　处：《电源技术》2009年第9期768-770,共3页Chinese Journal of Power Sources

基　　金：基金资助:国家自然科学基金(20663001;20763002);广西应用基础研究专项(桂科基0639032)

摘　　要：以氧化淀粉为碳前驱体和分散剂,采用冷冻干燥法制备LiFePO4/C正极材料,利用XRD、SEM、恒流充放电等手段对LiFePO4/C复合正极材料的物相结构、表观形貌及材料的电化学性能进行研究。结果表明:冷冻干燥法可以使原料变成粉末,同时不破坏其均匀的混合状态;以氧化淀粉为碳源,碳含量为7.07%,在700℃高温下煅烧12h合成的材料具有完整的晶型结构,颗粒大小均一,首次放电比容量达到l65mAh/g,接近理论放电比容量。1C倍率下,50次循环后的容量衰减仅为0.20%,5C倍率下,50次循环后的容量衰减为1.39%,电化学性能优异。The LiFePO4/C cathode materials was prepared by freeze drying method using oxidized starch as carbon source and dispersant, The structure, apparent morphology, electronic conductivity were characterized by means of XRD, SEM, electrochemical techniques. The optimized process conditions were： oxidized starch as carbon source, carbon content of 7.07%, calcinations temperature is 700 ℃, calcinations time is 12 h. The sample which was synthesized by the optimized technology conditions has a complete crystal structure, size of the particle uniformity, the first discharge capacity was 165 mAh/g, close to the theoretical discharge capacity. After 50 cycles at 1 C rate, the capacity fade is only 0.20%, and 50 cycles at 5 C rate,the capacity fade is only 1.39%.1t shows excellent electrochemical performance.

关 键 词：锂离子电池 正极材料 冷冻干燥:LiFePO4/C 

分 类 号：TM912.9[电气工程—电力电子与电力传动]