Insights into Changes in Voltage and Structure of Li2FeSiO4 Polymorphs for Lithium-Ion Batteries

被引：118

作者：

Eames, C. ^{[1
]}

Armstrong, A. R. ^{[2
]}

Bruce, P. G. ^{[2
]}

Islam, M. S. ^{[1
]}

机构：

[1] Univ Bath, Dept Chem, Bath BA2 7AY, Avon, England

[2] Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland

来源：

CHEMISTRY OF MATERIALS | 2012年 / 24卷 / 11期

基金：

英国工程与自然科学研究理事会;

关键词：

lithium battery; cathode; silicates; computer simulation; electronic structure; ELECTROCHEMICAL PERFORMANCE; CATHODE MATERIALS; CRYSTAL-STRUCTURE; LI2MSIO4; M; MN; FE; CO; TRANSPORT; DEFECTS; LIMPO4;

D O I：

10.1021/cm300749w

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：

The search for new low cost, safe, and high capacity cathodes for lithium batteries has focused attention recently on Li2FeSiO4. The material presents a challenge because it exhibits complex polymorphism, and when it is electrochemically cycled there is a significant drop in the cell voltage related to a structural change. Systematic studies based on density functional theory techniques have been carried out to examine the change in cell voltages and structures for the full range of Li2FeSiO4 polymorphs (beta(II), gamma(s), and gamma(II)) including the newly elucidated cycled structure (termed inverse-beta(II)). We find that the cycled structure has a 0.18-0.30 V lower voltage than the directly synthesized polymorphs in accord with experimental observations. The trends in cell voltage have been correlated to the change in energy upon delithiation from Li2FeSiO4 to LiFeSiO4 in which the cation-cation electrostatic repulsion competes with distortion of the tetrahedral framework.

引用

页码：2155 / 2161

页数：7

共 36 条

[1] Structure and Lithium Transport Pathways in Li2FeSiO4 Cathodes for Lithium Batteries [J].