Operando Observations and First-Principles Calculations of Reduced Lithium Insertion in Au-Coated LiMn2O4

被引：14

作者：

Bassett, Kimberly L. ^{[1
]}

Warburton, Robert E. ^{[2
]}

Deshpande, Siddharth ^{[2
]}

Fister, Timothy T. ^{[3
]}

Ta, Kim ^{[1
]}

Esbenshade, Jennifer L. ^{[1
]}

Kinaci, Alper ^{[4
]}

Chan, Maria K. Y. ^{[4
]}

Wiaderek, Kamila M. ^{[5
]}

Chapman, Karena W. ^{[5
]}

Greeley, Jeffrey P. ^{[2
]}

Gewirth, Andrew A. ^{[1
]}

机构：

[1] Univ Illinois, Dept Chem, Urbana, IL 61801 USA

[2] Purdue Univ, Davidson Sch Chem Engn, W Lafayette, IN 47907 USA

[3] Argonne Natl Lab, Chem Sci & Engn Div, Lemont, IL 60439 USA

[4] Argonne Natl Lab, Ctr Nanoscale Mat, Lemont, IL 60439 USA

[5] Argonne Natl Lab, Xray Sci Div, Lemont, IL 60439 USA

来源：

ADVANCED MATERIALS INTERFACES | 2019年 / 6卷 / 04期

基金：

美国国家科学基金会;

关键词：

density functional theory; lithium-ion batteries; lithium manganese oxide; operando X-ray diffraction; protective coatings; X-RAY-DIFFRACTION; DENSITY-FUNCTIONAL THEORY; TOTAL-ENERGY CALCULATIONS; ATOMIC LAYER DEPOSITION; CATHODE MATERIALS; PLANE-WAVE; SURFACE-MODIFICATION; SPINEL ELECTRODES; CYCLING STABILITY; ELECTROCHEMICAL LITHIATION;

D O I：

10.1002/admi.201801923

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The deposition of protective coatings on the spinel LiMn2O4 (LMO) lithium-ion battery cathode is effective in reducing Mn dissolution from the electrode surface. Although protective coatings positively affect LMO cycle life, much remains to be understood regarding the interface formed between these coatings and LMO. Using operando powder X-ray diffraction with Rietveld refinement, it is shown that, in comparison to bare LMO, the lattice parameter of a model Au-coated LMO cathode is significantly reduced upon relithiation. Less charge passes through Au-coated LMO in comparison to bare LMO, suggesting that the reduced lattice parameter is associated with decreased Li+ solubility in the Au-coated LMO. Density functional theory calculations show that a more Li+-deficient near-surface is thermodynamically favorable in the presence of the Au coating, which may further stabilize these cathodes through suppressing formation of the Jahn-Teller distorted Li2Mn2O4 phase at the surface. Electronic structure and chemical bonding analyses show enhanced hybridization between Au and LMO for delithiated surfaces leading to partial oxidation of Au upon delithiation. This study suggests that, in addition to transition metal dissolution from electrode surfaces, protective coating design must also balance potential energy effects induced by charge transfer at the electrode-coating interface.

引用

页数：11