Charging Mechanism of Li2MnO3

被引：91

作者：

Guerrini, Niccolo ^{[3
]}

Jin, Liyu ^{[3
]}

Lozano, Juan G. ^{[1
,2
]}

Luo, Kun ^{[1
,2
]}

Sobkowiak, Adam ^{[4
]}

Tsuruta, Kazuki ^{[5
]}

Massel, Felix ^{[6
]}

Duda, Laurent-Claudius ^{[6
]}

Roberts, Matthew R. ^{[3
]}

Bruce, Peter G. ^{[1
,2
]}

机构：

[1] Univ Oxford, Dept Mat, Oxford OX1 3PH, England

[2] Univ Oxford, Dept Chem, Oxford OX1 3PH, England

[3] Dyson Technol Ltd, Malmesbury SN16 0RP, England

[4] Etteplan Sweden AB, SE-17154 Solna, Sweden

[5] Japan Synchrotron Radiat Res Inst JASRI, Sayo, Hyogo 6795198, Japan

[6] Uppsala Univ, Dept Phys & Astron, Div Mol & Condensed Matter Phys, S-75120 Uppsala, Sweden

来源：

CHEMISTRY OF MATERIALS | 2020年 / 32卷 / 09期

基金：

英国工程与自然科学研究理事会;

关键词：

CATHODE MATERIALS; REDOX CHEMISTRY; LITHIUM; BATTERY; CYCLE; EVOLUTION;

D O I：

10.1021/acs.chemmater.9b04459

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：

Operando mass spectroscopy demonstrates quantitatively that lithium extraction from Li2MnO3 is charge compensated by oxygen loss (O-loss) not oxidation of oxide ions that are retained within the structural framework (O-redox). This fact is confirmed by X-ray absorption and emission spectroscopy. Li NMR shows that the two-phase core-shell structure, which forms on charging, is composed of an intact Li2MnO3 core and a highly disordered shell containing no Li, with a composition close to MnO2. Discharge involves Li insertion into the disordered shell. CO2 and O-2 are detected on charging at 15 mA g(-1), whereas charging by galvanostatic intermittent titration technique (GITT) forms only CO2; an observation in agreement with the previously described model of oxygen evolution from high-voltage cathodes producing singlet O-2 that reacts with the electrolyte forming CO2. The dominance of oxygen evolution over O-redox is in accordance with the model of O-loss occurring when the oxide ions are undercoordinated; O in the shell devoid of Li is coordinated by only 2 Mn.

引用

页码：3733 / 3740

页数：8

共 37 条

[1] Demonstrating oxygen loss and associated structural reorganization in the lithium battery cathode Li[Ni0.2Li0.2Mn0.6]O2 [J].