Differentiating allotropic LiCoO2/Li2Co2O4: A structural and electrochemical study

JOURNAL OF POWER SOURCES

卷:271

Article

Kan, Yongchun^1,2  Hu, Yuan¹  Ren, Yang³  Bareno, Javier²  Bloom, Ira²  Sun, Yang-Kook⁴  Amine, Khalil²  Chen, Zonghai² 

[1] Univ Sci & Technol China, State Key Lab Fire Sci, Hefei 230026, Anhui, Peoples R China

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

[3] Argonne Natl Lab, Xray Sci Div, Adv Photon Source, Lemont, IL 60439 USA

[4] Hanyang Univ, Dept WCU Energy Engn, Dept Chem Engn, Seoul 133791, South Korea

关键词: Allotropic structure;    Lithium cobalt oxide;    Structure property relationship;    Cation mixing;    Lithium battery;   

DOI  :  10.1016/j.jpowsour.2014.07.178

来源: Elsevier

【 摘 要 】

In situ high-energy X-ray diffraction was carried out to investigate the structural transformation of lithium cobalt oxides during the solid-state synthesis. Two allotropic phases were observed during the synthesis process; Li2Co2O4 with a spinel structure was formed within the temperature window between 450 degrees C and 650 degrees C, beyond which Li2Co2O4 was converted to its hexagonal counterpart, layered LiCoO2, through a cation exchange between Li and Co. In electrochemical tests, the Li2Co2O4 was estimated to have a very low reversible capacity, similar to 20 mAh g(-1), and a high initial irreversible capacity loss of about 80 mAh g(-1). An interfacial phase between layered LiCoO2 domain and spinel Li2Co2O4 domain was also identified by ex situ high-resolution X-ray diffraction. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

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