摘要
用酚醛树脂作炭源对锂离子电池正极材料LiFePO_4进行了改性,用XRD、恒电流充放电等方法研究了酚醛树脂对LiFePO_4纯度和电化学性能的影响.酚醛树脂在高温炭化过程中产生的H_2能够和LiFePO_4发生反应,生成Fe_2P等物质,导致材料中活性物质含量降低;采用先在650℃处理后再于750℃焙烧的方法,可以显著减少Fe_2P等物质的生成,提高材料的纯度和比容量,所制备的LiFePO_4在0.2C、1C、2C和5C(1C=50mA/g)倍率时的放电比容量分别达到160、150、135和120mAh/g,并具有较好的循环性能.
Lithium ion battery cathode material LiFePO4/C was prepared by using resorcinolformaldehyde resin as carbon source. Effects of resin on purity and electrochemical performance of LiFePO4 were investigated by XRD and galvanostatic charge-discharge test. The results indicate that the hydrogen resulted from pyrolysis of resorcinol-formaldehyde resin can react with LiFePO4, then Fe2P, FeP and Li3PO4 are formed. Such impurities will lead the capacity of the materials decrease. The impurities can be reduced significantly by carbonization at lower temperature before calcination at higher temperature. The capacity and cycle property of LiFePO4 are improved greatly by the addition of resorcinol-formaldehyde resin. The specific discharge capacity of LiFePO4 reaches up to 160, 150, 135 and 120mAh/g at 0.2C,1C,2C and 5C（1C=150mA/g） rates, respectively.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第5期864-868,共5页
Journal of Inorganic Materials
关键词
锂离子电池
LIFEPO4
酚醛树脂
电化学性能
lithium ion battery
LiFeP04
resorcinol-formaldehyde resin
electrochemical performance
