制备过程pH值对FePO4·xH2O及LiFePO4性能的影响

中国有色金属学报, 2008, 18(5): 867-872.

制备过程pH值对FePO4·xH2O及LiFePO4性能的影响

郑俊超 ^1, , 李新海 ^2, , 王志兴 ^3, , 郭华军 ^4, , 王丹琴 ^5,

1.中南大学,冶金科学与工程学院,长沙,410083

2.中南大学,冶金科学与工程学院,长沙,410083

3.中南大学,冶金科学与工程学院,长沙,410083

4.中南大学,冶金科学与工程学院,长沙,410083

5.中南大学,冶金科学与工程学院,长沙,410083

基金项目: 国家重点基础研究发展计划(973计划)(2007CB613607)

关键词：锂离子电池 , LiFePO4 , PO4·xH2 , 电化学性能

Effect of pH value on performance of FeeO4·xH2O and LiFePO4 in synthesis process

以FeSO4·7H2O,H3PO4,H2O2和NH3·H2O为原料合成FePO4·xH2O前驱体,考察制备过程溶液pH值对合成FePO4·xH2O前驱体性能的影响;将Li2CO3,FePO4·xH2O和乙炔黑球磨混合,通过低温固相反应合成LiFePO4.用X射线衍射和扫描电镜对FePO4·xH2O和LiFePO4进行结构和表面形貌表征,研究不同pH值条件下合成的FePO4·xH2O前驱体为原料对制备的LiFePO4电化学性能的影响.结果表明:溶液pH值1.5时制备的FePO4·xH2O中含有少量Fe(PO4)2(OH)2杂质.当pH分别为2、3、4和5时,合成的FePO4·xH2O均为纯相.pH值为2左右合成的FePO4·xH2O前驱体制备出的LiFePO4具有良好的电化学性能;其振实密度达1.11 g/cm3.

参考文献

[1]	Padhi AK.;Goodenough JB.;Nanjundaswamy KS. .PHOSPHO-OLIVINES AS POSITIVE-ELECTRODE MATERIALS FOR RECHARGEABLE LITHIUM BATTERIES[J].Journal of the Electrochemical Society,1997(4):1188-1194.
[2]	A. Yamada;S.C. Chung;K. Hinokuma .Optimized LiFePO_4 for Lithium Battery Cathodes[J].Journal of the Electrochemical Society,2001(3):A224-A229.
[3]	HUANG H;YIN S C;NAZAR L F .Approaching theoretical capacity of LiFePO4 at room temperature at high rates[J].Electrochemical and Solid-State Letters,2001,4(10):A170-A172.
[4]	C.H. Mi;G.S. Cao;X.B. Zhao .Low-cost, one-step process for synthesis of carbon-coated LiFePO_4 cathode[J].Materials Letters,2005(1):127-130.
[5]	G. Meligrana;C. Gerbaldi;A. Tuel .Hydrothermal synthesis of high surface LiFePO_4 powders as cathode for Li-ion cells[J].Journal of Power Sources,2006(1):516-522.
[6]	HU Yao-qin;DOEFF M M;KOSTECHI R;FINONES R .Electrochemical performance of sol-gel synthesized LiFePO4[J].Journal of the Electrochemical Society,2004,151(12):1279-1285.
[7]	K. S. Park;J. T. Son;H. T. Chung;S. J. Kim;C. H. Lee;H. G. Kim .Synthesis of LiFePO_4 by co-precipitation and microwave heating[J].Electrochemistry communications,2003(10):839-842.
[8]	ARNODE O;GARCHE J;HEMMER R;STROBELE S .Fine-particle iron phosphate LiFePO4 synthesized by a new low-cost aqueous precipitation technique[J].Journal of Power Sources,2003,119-121:247-251.
[9]	Masashi Higuchi;Keiichi Katayama;Yasuo Azuma;Megumi Yukawa;Manabu Suhara .Synthesis of LiFePO_4 cathode material by microwave processing[J].Journal of Power Sources,2003(119/121):258-261.
[10]	BAKER J;SAIDI M Y;SWOYER J L .Lithium iron (Ⅱ) phosphate olivines prepared by a novel carbonthermal reduction method[J].Electrochemical and Solid-State Letters,2003,6(03):A53-A55.
[11]	DELACOURT C;WURM C;REALE P .Low temperature preparation of optimized phosphates for Li-battery applications[J].Solid State Ionics,2004,173(1-4):113-118.
[12]	朱炳权,李新海,张宝,王志兴,郭华军.改进的碳热还原法制备正极材料LiFePO4/C[J].电池,2005(06):445-447.
[13]	雷敏,应皆荣,姜长印,万春荣.高密度球形LiFePO4的合成及性能[J].电源技术,2006(01):11-13.
[14]	郑忠.胶体科学导论[M].北京:高等教育出版社,1989:17-18.
[15]	HUANG H;YIN S C;NAZAR L F .Approaching theoretical capacity of LiFePO4 at room temperature at high rate[J].Electrochemical and Solid-State Letters,2001,4(10):A170-173.
[16]	Pier Paolo Prosini;Daniela Zane;Mauro Pasquali .Improved electrochemical performance of a LiFePO_4-based composite cathode[J].Electrochimica Acta,2001(23):3517-3523.

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