Suppression of Phase Separation in LiFePO4 Nanoparticles During Battery Discharge

被引：400

作者：

Bai, Peng ^{[1
,3
]}

Cogswell, Daniel A. ^{[1
]}

Bazant, Martin Z. ^{[1
,2
]}

机构：

[1] MIT, Dept Chem Engn, Cambridge, MA 02139 USA

[2] MIT, Dept Math, Cambridge, MA 02139 USA

[3] Tsinghua Univ, State Key Lab Automot Safety & Energy, Dept Automot Engn, Beijing 100084, Peoples R China

来源：

NANO LETTERS | 2011年 / 11卷 / 11期

基金：

美国国家科学基金会;

关键词：

Li-ion battery; LiFePO4; phase-field model; Butler-Volmer equation; spinodal decomposition; intercalation waves; RECHARGEABLE LITHIUM BATTERIES; TRANSFORMATION ELECTRODES; POSITIVE-ELECTRODE; STORAGE ELECTRODES; PHOSPHO-OLIVINES; PARTICLE-SIZE; MODEL; STRAIN; ENERGY; TEMPERATURE;

D O I：

10.1021/nl202764f

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Using a novel electrochemical phase-field model, we question the common belief that LiXFePO4 nanoparticles always separate into Li-rich and Li-poor phases during battery discharge. For small currents, spinodal decomposition or nucleation leads to moving phase boundaries. Above a critical current density (in the Tafel regime), the spinodal disappears, and particles fill homogeneously, which may explain the superior rate capability and long cycle life of nano-LiFePO4 cathodes.

引用

页码：4890 / 4896

页数：7

共 57 条

[51] The Role of Coherency Strains on Phase Stability in LixFePO4: Needle Crystallites Minimize Coherency Strain and Overpotential [J].