Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Correlating capacity fading and structural changes in Li1+yMn2-yO4-delta spinel cathode materials - A systematic study on the effects of Li/Mn ratio and oxygen deficiency
Autore:
Xia, YY; Sakai, T; Fujieda, T; Yang, XQ; Sun, X; Ma, ZF; McBreen, J; Yoshio, M;
Indirizzi:
Osaka Natl Res Inst, Battery Sect, Osaka 5638577, Japan Osaka Natl Res Inst Osaka Japan 5638577 ttery Sect, Osaka 5638577, Japan Brookhaven Natl Lab, Upton, NY 11973 USA Brookhaven Natl Lab Upton NY USA11973 aven Natl Lab, Upton, NY 11973 USA Saga Univ, Dept Appl Chem, Saga 8408502, Japan Saga Univ Saga Japan 8408502 a Univ, Dept Appl Chem, Saga 8408502, Japan
Titolo Testata:
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
fascicolo: 7, volume: 148, anno: 2001,
pagine: A723 - A729
SICI:
0013-4651(200107)148:7<A723:CCFASC>2.0.ZU;2-W
Fonte:
ISI
Lingua:
ENG
Soggetto:
RECHARGEABLE LITHIUM BATTERIES; X-RAY-DIFFRACTION; PHASE-TRANSITION; LI/LIMN2O4 CELLS; ION BATTERIES; LIMN2O4; INSERTION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Engineering, Computing & Technology
Citazioni:
22
Recensione:
Indirizzi per estratti:
Indirizzo: Xia, YY Osaka Natl Res Inst, Battery Sect, Osaka 5638577, Japan Osaka NatlRes Inst Osaka Japan 5638577 ct, Osaka 5638577, Japan
Citazione:
Y.Y. Xia et al., "Correlating capacity fading and structural changes in Li1+yMn2-yO4-delta spinel cathode materials - A systematic study on the effects of Li/Mn ratio and oxygen deficiency", J ELCHEM SO, 148(7), 2001, pp. A723-A729

Abstract

Several series of Li1+/-yMn2O4+/-delta samples with the spinel structure were synthesized. These samples had different Li/Mn ratios (by varying the Li/Mn ratio used in stirling materials) and various oxygen contents (by controlling synthesis conditions, including temperature, heat-treatment time, and purging gas during both the solid-state reaction and annealing). In systematic studies of charge-discharge cycling behavior and in situ X-ray diffraction (XRD) at room temperature, it was found that both the charge/ discharge profile and the structural changes during cycling are closely related to the degree of oxygen deficiency created in the synthesis process. Their effects on the capacity fading are much more important than the Li/Mn ratio or other factors. A higher degree of oxygen deficiency is accompanied with a faster fading of capacity during cycling. In cells using spinel cathodes with an oxygen deficiency. the capacity fading during cycling occurs on both the 4.2 and 4.0 V plateaus. This behavior is quite different from that found in cathodes without an oxygen deficiency, where most of the capacity fading occurs on the 4.7 V plateau region only. Our in situ XRD results indicate clearly that the capacity fading on the 4.2 V plateau is related to thephase transition between the cubic II and cubic III (lambda -MnO2) structure, while the capacity fading on the 4.0 V plateau is related to the phase transition between the cubic I and cubic II spinel structures. The effects of oxygen deficiency on the structural phase transition of Li1+/-yMn2O4+/-delta-type materials at temperatures around 10 degreesC were also studied. It was found that this phase transition is closely related to the degree of oxygen deficiency of the material. In samples with no oxygen deficiency, this phase transition disappeared. (C) 2001 The Electrochemical Society.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/09/20 alle ore 00:57:40