Amphoteric effects of Fe2P on electrochemical performance of lithium iron phosphate-carbon composite synthesized by ball-milling and microwave heating

被引：56

作者：

Song, Min-Sang ^{[1
]}

Kim, Dong-Yung ^{[1
]}

Kang, Yong-Mook ^{[2
]}

Kim, Yong-Il ^{[3
]}

Lee, Jai-Young ^{[4
,5
]}

Kwon, Hyuk-Sang ^{[1
]}

机构：

[1] Korea Adv Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea

[2] Kongju Natl Univ, Div Adv Mat Engn, Cheonan, Chungnam, South Korea

[3] Korea Res Inst Stand & Sci, Taejon, South Korea

[4] Konkuk Univ, INVEST, Seoul, South Korea

[5] Konkuk Univ, Dept Adv Technol Fus, Seoul, South Korea

来源：

JOURNAL OF POWER SOURCES | 2008年 / 180卷 / 01期

关键词：

lithium iron phosphate-carbon composites; discharge capacity; rate capability; cyclic retention; critical concentration; lithium-ion battery;

D O I：

10.1016/j.jpowsour.2008.01.079

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Lithium iron phosphate-carbon (LiFePO4-C) Composites with various amounts of Fe2P are synthesized by ball-milling coupled with microwave heating to serve as cathodes for lithium-ion batteries. LiFePO4-C in which Fe2P is restrained below a critical concentration gives as very high discharge capacity of 165 mAh g(-1), excellent rate capability (85.4% C/50-rate discharge capacity at 2C) and stable cyclic retention for 250 cycles. Above the critical concentration however, electrochemical performance deterioated. Analysis and debate, based on a comparison of the physical and electrochemical properties among LiFePO4-C composites with the variation of Fe2P, proceeded to the conclusion that below the critical concentration, Fe2P enhanced the conductivity of LiFePO4-C, whereas above the critical concentration, it blocked the one-dimensional Li+ pathways in LiFePO4 and might hinder Li+ movement in LiFePO4. Therefore, in order to obtain a LiFePO4-C composite that enhances electrochemical performance, it is concluded that the amount of Fe2P should be carefully controlled below its critical concentration. (C) 2008 Elsevier B.V. All rights reserved.

引用

页码：546 / 552

页数：7

共 33 条

[11] Carbon surface layers on a high-rate LiFePO4 [J].

Gabrisch, Heike ;

Wilcox, James D. ;

Doeff, Marca M. .

ELECTROCHEMICAL AND SOLID STATE LETTERS, 2006, 9 (07) :A360-A363

[12]

Gibb T. C., 1976, PRINCIPLES MOBSSBAUE, P73

[13] Nano-network electronic conduction in iron and nickel olivine phosphates [J].

Herle, PS ;

Ellis, B ;

Coombs, N ;

Nazar, LF .

NATURE MATERIALS, 2004, 3 (03) :147-152

[14] Approaching theoretical capacity of LiFePO4 at room temperature at high rates [J].

Huang, H ;

Yin, SC ;

Nazar, LF .

ELECTROCHEMICAL AND SOLID STATE LETTERS, 2001, 4 (10) :A170-A172

[15] Atomic-scale investigation of defects, dopants, and lithium transport in the LiFePO4 olivine-type battery material [J].

Islam, MS ;

Driscoll, DJ ;

Fisher, CAJ ;

Slater, PR .

CHEMISTRY OF MATERIALS, 2005, 17 (20) :5085-5092

[16] ARC studies of the thermal stability of three different cathode materials:: LiCoO2; Li[Ni0.1Co0.8Mn0.1]O2; and LiFePO4, in LiPF6 and LiBoB EC/DEC electrolytes [J].

Jiang, J ;

Dahn, JR .

ELECTROCHEMISTRY COMMUNICATIONS, 2004, 6 (01) :39-43

[17]

Larson A. C., 1994, 86 LAUR LOS AL NAT L

[18] A comparison of the electrode/electrolyte reaction at elevated temperatures for various Li-ion battery cathodes [J].

MacNeil, DD ;

Lu, ZH ;

Chen, ZH ;

Dahn, JR .

JOURNAL OF POWER SOURCES, 2002, 108 (1-2) :8-14

[19]

Nakayama M, 2003, SOLID STATE IONICS, V164, P35, DOI [10.1016/j.ssi.2003.08.048, 10.1016/j.ssi.2003-08.048]

[20] Effect of structure on the Fe3+/Fe2+ redox couple in iron phosphates [J].

Padhi, AK ;

Nanjundaswamy, KS ;

Masquelier, C ;

Okada, S ;

Goodenough, JB .

JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1997, 144 (05) :1609-1613

← 1 2 3 4 →