Vanadyl phosphates of VOPO4 as a cathode of Li-ion rechargeable batteries

Bustam M. Azmi, Tatsumi Ishihara, Hiroyasu Nishiguchi, Yusaku Takita

Research output: Contribution to journalConference article

52 Citations (Scopus)

Abstract

Seven phases of VOPO4 were synthesized and their Li intercalation properties were investigated. Li can be reversibly intercalated into all phases of VOPO4 and potential plateaus for Li intercalation and de-intercalation exist at 3.7 and 3.9 V, respectively, except for the β- and ε-phases. β- and ε-phases of VOPO4 exhibit slightly higher flat potentials of 3.9 and 4.1 V. The capacity for Li intercalation is strongly affected by the crystal structure of VOPO4 and the Li intercalation capacity increases with increasing average valence of V. Among the VOPO4 crystal phases, it was found that the δ-phase exhibits the largest reversible capacity of ca. 130 mAh/g. The capacity for Li de-intercalation in δ-phase VOPO4 hardly decreased over 35 charge and discharge cycles. On the other hand, the Li intercalation capacity in δ-phase VOPO4 decreased with increasing current density for charge and discharge and temperature. However, even at a current density of 0.4 mA/cm2, corresponding to C/5, fairly large capacity of ca. 60 mAh/g was sustained, and at a operating temperature or 323 K, a capacity of 110 mAh/g was exhibited at 0.04 mA/cm2.

Original languageEnglish
Pages (from-to)273-277
Number of pages5
JournalJournal of Power Sources
Volume119-121
DOIs
Publication statusPublished - Jun 1 2003
Externally publishedYes
EventSelected Papers Presented at the 11th IMLB - Monterey, CA, United States
Duration: Jun 22 2002Jun 28 2002

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All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

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