加碳方式对磷酸铁锂动力学及电化学性能的影响.pdf

第 38 卷第 5 期中南大学学报(自然科学版) Vo l .3 8
2007 年 10 月 J. Cent. South Univ. (Science and Technology) Oct. 2007

加碳方式对磷酸铁锂动力学及电化学性能的影响

张宝,彭春丽,王志兴,王云燕,李新海

(中南大学冶金科学与工程学院,湖南长沙,410083)

摘要:以 FeSO4·7H2O 和 NH4H2PO4 为原料,以 H2O2 为氧化剂,通过液相沉淀法制得前驱体 FePO4,然后通过
碳热还原反应制得 LiFePO4。采用 2 种加碳方式:方法一是先制得 FePO4,然后加入乙炔黑混合后高温合成 LiFePO4;
方法二是先把乙炔黑分散在液相中,然后通过液相沉淀制得含碳的 FePO4,再高温合成 LiFePO4。研究结果表明:
采用方法二合成的 LiFePO4 动力学及电化学性能比方法一合成的优。采用方法二所制备的 LiFePO4 样品以 的
倍率放电,其比容量达 149 mA·h/g;当放电倍率为 1C 时,其比容量为 124 mA·h/g,且循环性能良好。
关键词:锂离子电池;LiFePO4;交流阻抗;液相沉淀;碳热还原
中图分类号: 文献标识码:A 文章编号:1672-7207(2007)05−0863−04

Effect of adding carbon modes on ic and
electrochemical performances of LiFePO4

ZHANG Bao, PENG Chun-li, WANG Zhi-xing, WANG Yun-yan, LI Xin-hai

(School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)

Abstract: Two samples of LiFePO4 were synthesized with different adding carbon modes. In the first method, acetylene
black was mixed with FePO4 which was prepared by aqueous precipitation of FePO4 from FeSO4·7H2O and NH4H2PO4
with hydrogen peroxide as oxidizing agent, then LiFePO4 was synthesized by carbothermal reduction. In the second
method, acetylene black was mixed with FePO4 in liquid during the process of aqueous precipitation, and then LiFePO4
was synthesized with the same condition. The