6533b85cfe1ef96bd12bd2f3
RESEARCH PRODUCT
Characterization of LiFePO4/C Composite Thin Films Using Electrochemical Impedance Spectroscopy
A. LusisJanis SmitsGints KucinskisJānis KleperisG. Bajarssubject
Materials sciencechemistrySputteringDouble-layer capacitanceAnalytical chemistrychemistry.chemical_elementLithiumSputter depositionThin filmCyclic voltammetryElectrode potentialDielectric spectroscopydescription
The composite LiFePO4/C thin films were prepared on steel substrate by radio frequency (RF) magnetron sputtering. Electrochemical properties of the obtained thin films were investigated by cyclic voltammetry charge-discharge measurements and electrochemical impedance spectroscopy (EIS). The films annealed at 550 °C exhibited a couple of redox peaks at 3.45 V vs. Li/Li + characteristic for the electrochemical lithium insertion/extraction in LiFePO4. At low current rate such composite thin film showed a discharge capacity of over 110 mAh g -1 . The dependence of charge transfer resistance, double layer capacitance and lithium diffusion coefficients on applied electrode potential were calculated from EIS data. Determined values of lithium diffusion coefficient were in the range from 8.3·10 -13 cm 2 s -1 to 1.2·10 -13 cm 2 s -1 at 3.4 V and 3.7 V, respectively.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-08-20 | IOP Conference Series: Materials Science and Engineering |