Improvement of electrochemical and thermal stability of LiFePO4@C batteries by depositing amorphous silicon film

Lin, Yingbin; Yang, Yue; Lin, Ying; Zeng, Baozhi; Zhao, Guiying; Huang, Zhigao

doi:10.1016/j.electacta.2011.03.134

Cited by 6 publications

(1 citation statement)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both EIS profiles are composed of a depressed semicircle at high frequencies and a spike at low frequencies. The depressed semicircle in high frequency region on the real axis is mainly attributed to the charge transfer process [24] and the sloping line in low frequency region is ascribed to the warburg impedance associated with lithium ion diffusion [25] . It is found that LiFePO 4 /C-Ge film has smaller charge-transfer resistance (R ct = 72.73Ω) than that of the pristine one (=209.6Ω), which is ascribed to the highly conductive Ge film on the LiFePO 4 /C electrode and the suppression of SEI layer.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Electrochemical Performances of LiFePO<sub>4</sub>/C Cathode Materials by Deposited with Ge Film

Huang

Lin

Huang

2014

AMR

View full text Add to dashboard Cite

LiFePO4/C-Ge electrodes were prepared with vacuum thermal evaporation deposition by depositing Ge films on as-prepared LiFePO4/C electrodes. The effect of Ge film on the electrochemical performances of LiFePO4/C cells was investigated systematically by charge/discharge testing, cyclic voltammograms and AC impedance spectroscopy, respectively. It was found that Ge-film-surface modified LiFePO4/C showed excellent electrochemical performances compared to that of the pristine one in terms of cyclability and rate capability. At 60°C, LiFePO4/C-Ge film exhibited outstanding cyclability with less than 5% capacity fade after 50 cycles while the pristine one suffers 15%. Analysis from the electrochemical measurements showed that the presence of Ge film on the LiFePO4/C electrode would protect active material from HF generated by the decomposition of LiPF6 in the electrolyte and stabilize the surface structure of active material during the charge and discharge cycle. Electrochemical impedance spectroscopy (EIS) results indicated that Ge film mainly reduced the charge transfer resistance Rct of LiFePO4/C electrode, resulting from the suppression of the solid electrolyte interfacial (SEI) film.

show abstract

Section: Resultsmentioning

confidence: 99%