Overcapacity of Li [NixLi1/3-2x/3Mn 2/3-x/3] O2 electrodes

Alastair D. Robertson; Peter G. Bruce

doi:10.1149/1.1783114

Overcapacity of Li [Ni_xLi₁/_3-2x/₃Mn _2/3-x/3] O₂ electrodes

Alastair D. Robertson^*
, Peter G. Bruce

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

88 Citations (Scopus)

Abstract

Layered lithium intercalation materials Li[Ni_xLi _1/3-2x/3Mn_2/3-x/3]O₂ with O₃ structure are based on the layered compound Li₂MnO₃ (Li[Li_1/3Mn_2/3]O₂) in which 1 Mn⁴⁺ and 2Li⁺ ions are replaced by 3Ni²⁺. On initial deintercalation of lithium, Ni²⁺ is oxidized to Ni⁴⁺ but further lithium removal is possible. Two mechanisms have been considered to explain the ability to overcharge, simultaneous oxygen loss or H⁺ exchange the latter are generated from decomposition of the electrolyte. We show that the dominant mechanism of Li overcapacity during electrochemical charging is oxygen loss, in agreement with Dahn's results. Some H⁺ exchange does occur, however, and this is greater at 55°C than at 30°C, accounting for about 25% of the excess lithium removed at the higher temperature. In contrast to electrochemical charging, chemical removal of lithium using NO₂BF₄ is accompanied by more H⁺ exchange than oxygen loss.

Original language	English
Pages (from-to)	A294-A298
Number of pages	5
Journal	Electrochemical and Solid-State Letters
Volume	7
Issue number	9
Early online date	16 Aug 2004
DOIs	https://doi.org/10.1149/1.1783114
Publication status	Published - 18 Oct 2004
Externally published	Yes

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

Keywords

Lithium compounds
Nickel compounds
Manganese compounds
Intercalation compounds
Electrolytes
Electrolysis
Electrochemical electrodes
Dissociation

Access to Document

10.1149/1.1783114

Cite this

@article{cdf93e65824d4fe98ad2df622986db9e,

title = "Overcapacity of Li [NixLi1/3-2x/3Mn 2/3-x/3] O2 electrodes",

abstract = "Layered lithium intercalation materials Li[NixLi 1/3-2x/3Mn2/3-x/3]O2 with O3 structure are based on the layered compound Li2MnO3 (Li[Li1/3Mn2/3]O2) in which 1 Mn4+ and 2Li+ ions are replaced by 3Ni2+. On initial deintercalation of lithium, Ni2+ is oxidized to Ni4+ but further lithium removal is possible. Two mechanisms have been considered to explain the ability to overcharge, simultaneous oxygen loss or H+ exchange the latter are generated from decomposition of the electrolyte. We show that the dominant mechanism of Li overcapacity during electrochemical charging is oxygen loss, in agreement with Dahn's results. Some H+ exchange does occur, however, and this is greater at 55°C than at 30°C, accounting for about 25\% of the excess lithium removed at the higher temperature. In contrast to electrochemical charging, chemical removal of lithium using NO2BF4 is accompanied by more H+ exchange than oxygen loss.",

author = "Robertson, \{Alastair D.\} and Bruce, \{Peter G.\}",

year = "2004",

month = oct,

day = "18",

doi = "10.1149/1.1783114",

language = "English",

volume = "7",

pages = "A294--A298",

journal = "Electrochemical and Solid-State Letters",

issn = "1099-0062",

publisher = "Electrochemical Society Inc.",

number = "9",

}

TY - JOUR

T1 - Overcapacity of Li [NixLi1/3-2x/3Mn 2/3-x/3] O2 electrodes

AU - Robertson, Alastair D.

AU - Bruce, Peter G.

PY - 2004/10/18

Y1 - 2004/10/18

N2 - Layered lithium intercalation materials Li[NixLi 1/3-2x/3Mn2/3-x/3]O2 with O3 structure are based on the layered compound Li2MnO3 (Li[Li1/3Mn2/3]O2) in which 1 Mn4+ and 2Li+ ions are replaced by 3Ni2+. On initial deintercalation of lithium, Ni2+ is oxidized to Ni4+ but further lithium removal is possible. Two mechanisms have been considered to explain the ability to overcharge, simultaneous oxygen loss or H+ exchange the latter are generated from decomposition of the electrolyte. We show that the dominant mechanism of Li overcapacity during electrochemical charging is oxygen loss, in agreement with Dahn's results. Some H+ exchange does occur, however, and this is greater at 55°C than at 30°C, accounting for about 25% of the excess lithium removed at the higher temperature. In contrast to electrochemical charging, chemical removal of lithium using NO2BF4 is accompanied by more H+ exchange than oxygen loss.

AB - Layered lithium intercalation materials Li[NixLi 1/3-2x/3Mn2/3-x/3]O2 with O3 structure are based on the layered compound Li2MnO3 (Li[Li1/3Mn2/3]O2) in which 1 Mn4+ and 2Li+ ions are replaced by 3Ni2+. On initial deintercalation of lithium, Ni2+ is oxidized to Ni4+ but further lithium removal is possible. Two mechanisms have been considered to explain the ability to overcharge, simultaneous oxygen loss or H+ exchange the latter are generated from decomposition of the electrolyte. We show that the dominant mechanism of Li overcapacity during electrochemical charging is oxygen loss, in agreement with Dahn's results. Some H+ exchange does occur, however, and this is greater at 55°C than at 30°C, accounting for about 25% of the excess lithium removed at the higher temperature. In contrast to electrochemical charging, chemical removal of lithium using NO2BF4 is accompanied by more H+ exchange than oxygen loss.

U2 - 10.1149/1.1783114

DO - 10.1149/1.1783114

M3 - Article

AN - SCOPUS:4944251802

SN - 1099-0062

VL - 7

SP - A294-A298

JO - Electrochemical and Solid-State Letters

JF - Electrochemical and Solid-State Letters

IS - 9

ER -