自然科学版 英文版
自然科学版 英文版
自然科学版 英文版

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中南大学学报(英文版)

Journal of Central South University

Vol. 12    No. 3    June 2005

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Electrochemical impedance spectra of V2O5xerogel
films with intercalation of lithium ion
ZHANG Yong(张 勇)1, 2, LIU Yu-wen(刘玉文)2, CHENG Yu-shan(程玉山) 2,
 HU Xin-guo(胡信国)1

1. Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001, China;
2. Jiangmen JJJ Battery Company Limited, Jiangmen 529000, China

Abstract:Vanadium pentoxide xerogel films used for lithium rechargeable batteries were prepared from crystalline c-V2O5 by melt quenching method,then the electrochemical process of lithium intercalation into vanadium pentoxide xerogel films was simulated with an equivalent circuit model, which was derived from the mechanism of electrode reactions. Measured electrochemical impedance spectra at various electrode potentials were analyzed by using the complex non-linear least-squares fitting method. The results show that impedance spectra consist of 2 high-to-medium
frequency depressed arcs and a low frequency straight line. The high frequency arc is attributed to the absorption reaction of lithium ions into the oxide film, the medium frequency arc is attributed to the charge transfer reaction at the vanadium oxide/electrolyte interface and the low frequency is characterized by a straight line with a phase angle of 45°corresponding to the diffusion of lithium ion through vanadium oxide phase. The experimental and calculated results are compared and discussed focusing on the electrochemical performance and the state of charge of the electrode. Moreover, the high consistence of the fitted values of the model to the experimental data indicates that this mathematical model does give a satisfying description of the intercalation process of vanadium pentoxide xerogel films.

 

Key words: vanadium pentoxide xerogel films; electrochemical impedance spectra; equivalent circuit; melt quenching method; lithium rechargeable batteries

中南大学学报(自然科学版)
  ISSN 1672-7207
CN 43-1426/N
ZDXZAC
中南大学学报(英文版)
  ISSN 2095-2899
CN 43-1516/TB
JCSTFT
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