Tris(2,2,2-trifluoroethyl) phosphite as a co-solvent for nonflammable electrolytes in Li-ion batteries

被引:163
作者
Zhang, SS [1 ]
Xu, K [1 ]
Jow, TR [1 ]
机构
[1] USA, Res Lab, Sensors & Electron Devices Directorate, Adelphi, MD 20783 USA
关键词
Li-ion battery; nonflammable electrolyte; phosphite; phosphate; fire retardant;
D O I
10.1016/S0378-7753(02)00537-2
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
In this work, we used tris(2,2,2-trifluoroethyl) phosphite (TTFP), in which the oxidization number of phosphorus was three (III), to formulate nonflammable electrolytes of the Li-ion batteries. Using 1 m (mole solute per kilogram solvent) LiPF6 3:3:4 (w) propylene carbonate (PC)/ethylene carbonate (EC)/ethyl methyl carbonate (EMC) electrolyte as a baseline, the effect of TTFP on the flammability and conductivity of the electrolytes, as well as the cell performance was evaluated. It is observed that the addition of TTFP can substantially reduce flammability of the electrolytes at a small expense in the ionic conductivity. When the TTFP content reaches 15 wt.% versus the solvent, the electrolyte becomes nonflammable. In Li/graphite half-cell, TTFP not only suppresses PC decomposition and graphite exfoliation but also increases Coulombic efficiency (CE) of the lithiation and delithiation cycle. In Li/cathode (a lithium nickel-based mixed oxide cathode) half-cell, TTFP has negligible adverse impact on the cycling performance when the cells are cycled between 2.7 and 4.2 V. In graphite/cathode Li-ion cell using PC-based electrolytes, TTFP can improve cycling performance, especially at high temperature (60 degreesC), since its presence favors the formation of solid electrolyte interface (SEI) film on the graphite electrode and increases thermal stability of LiPF6-based electrolytes. (C) 2002 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:166 / 172
页数:7
相关论文
共 31 条
[11]   Electrochemical and structural characterization of LiNi1-yCoyO2 (0 ≤ y ≤ 0.2) positive electrodes during initial cycling [J].
Lee, KK ;
Kim, KB .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2000, 147 (05) :1709-1717
[12]  
Levy S.C., 1994, BATTERY HAZARDS ACCI
[13]   Thermal properties of lithium-ion battery and components [J].
Maleki, H ;
Al Hallaj, S ;
Selman, JR ;
Dinwiddie, RB ;
Wang, H .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1999, 146 (03) :947-954
[14]   Thermal stability studies of Li-ion cells and components [J].
Maleki, H ;
Deng, GP ;
Anani, A ;
Howard, J .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1999, 146 (09) :3224-3229
[15]   A fire-resistant organophosphorus gel polymer electrolyte additive for use in rechargeable lithium batteries [J].
Morford, RV ;
Kellam, EC ;
Hofmann, MA ;
Baldwin, R ;
Allcock, HR .
SOLID STATE IONICS, 2000, 133 (3-4) :171-177
[16]  
NARANG SC, 2001, Patent No. 6168885
[17]  
NARANG SC, 1998, Patent No. 5830600
[18]   FORMATION OF LITHIUM-GRAPHITE INTERCALATION COMPOUNDS IN NONAQUEOUS ELECTROLYTES AND THEIR APPLICATION AS A NEGATIVE ELECTRODE FOR A LITHIUM ION (SHUTTLECOCK) CELL [J].
OHZUKU, T ;
IWAKOSHI, Y ;
SAWAI, K .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1993, 140 (09) :2490-2498
[19]  
OLSEN I, 1995, Patent No. 5455127
[20]  
PASQUIER AD, 1998, J ELECTROCHEM SOC, V145, P472