Electrochemical Impedance Spectroscopy on the Performance Degradation of LiFePO4/Graphite Lithium-Ion Battery Due to Charge-Discharge Cycling under Different C-Rates

• Abe, Yusuke

• Hori, Natsuki

• Kumagai, Seiji

抄録

Lithium-ion batteries (LIBs) using a LiFePO4 cathode and graphite anode were assembled in　coin cell form and subjected to 1000 charge-discharge cycles at 1, 2, and 5 C at 25 C. The performance　degradation of the LIB cells under di erent C-rates was analyzed by electrochemical impedance　spectroscopy (EIS) and scanning electron microscopy. The most severe degradation occurred at 2 C　while degradation was mitigated at the highest C-rate of 5 C. EIS data of the equivalent circuit model　provided information on the changes in the internal resistance. The charge-transfer resistance within　all the cells increased after the cycle test, with the cell cycled at 2 C presenting the greatest increment　in the charge-transfer resistance. Agglomerates were observed on the graphite anodes of the cells　cycled at 2 and 5 C; these were more abundantly produced in the former cell. The lower degradation　of the cell cycled at 5 C was attributed to the lowered capacity utilization of the anode. The larger cell　voltage drop caused by the increased C-rate reduced the electrode potential variation allocated to the　net electrochemical reactions, contributing to the charge-discharge specific capacity of the cells.

収録刊行物

• Energies

  Energies 12 (23), 4507-, 2019

  MDPI

キーワード

• lithium-ion battery
• degradation
• capacity fading
• electrochemical impedance spectroscopy
• LiFePO4
• graphite

詳細情報

• CRID: 1050853022583450240
• NII論文ID: 120007169392
• ISSN: 19961073
• DOI: 10.3390/en12234507
• HANDLE: 10295/00005794
• Web Site: https://air.repo.nii.ac.jp/records/5475
• Web Site: https://www.mdpi.com/1996-1073/12/23/4507/pdf
• 本文言語コード: en
• 資料種別: journal article
• データソース種別:
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  • Crossref
  • CiNii Articles
  • KAKEN