XPS and Mössbauer Spectroscopy of LiFePO4 and LiFePO4/C Ceramics
FM&NT 2015: Functional Materials and Nanotechnologies: Abstract Book 2015
Vilma Venckute, Jonas Reklaitis, R. Davidonis, Antonija Dindune, Dagnija Valdniece, V. Kazlauskiene, J. Miškinis, Tomas Šalkus, Antanas Orliukas, D. Baltrunas

LiFePO4 crystallizes in olivine structure. It is a mixed electronic-ionic conductor and has been proposed as an attractive cathode material for Li-ion secondary batteries. The conductivity values increased with increasing the amount of carbon in the LiFePO4/C composites [2]. It is known [3] that in this compound Fe2+ can be oxidized to Fe3+. The material has a high reversible capacity (~160 mAhg-1) and the intercalation potential for Li/Li+ is 3.5 V The redox behavior of the iron in this compound also makes it an interesting candidate for X-ray photoelectron spectroscopy (XPS) and the Mössbauer spectra study in the pure LiFePO4 and carbon containing LiFePO4/C ceramics. The LiFePO4 powders for the XPS and Mössbauer spectra study have been synthesized by solid state reaction and LiFePO4/C composites were synthesized by a sol-gel method and later sintered in argon gas.The ceramics of LiFePO4 was sintered in air. The binding energies of Fe 2p, P 2p and O 1s core level of the LiFePO4 ceramics and LiFePO4/C composite surfaces have been determined by XPS at room temperature. The analysis of Fe 2p, P 2p and O 1s core level XPS deconvolution is presented in this work. Mössbauer spectroscopy in the temperature range from 10 K to 700 K has been applied in order to determine phase transition temperatures, the Debye-Waller factor and typical ionization states of iron in compounds. Behavior of Li+ ions was evaluated in the second coordination sphere of iron based on changes in hyperfine parameters of Mössbauer spectra.


Keywords
Li-ion secondary batteries, XPS , Mössbauer spectroscopy
Hyperlink
http://www.fmnt.ff.vu.lt/wp-content/uploads/2015/10/Abstract-Book-FMNT-2015.pdf

Venckute, V., Reklaitis, J., Davidonis, R., Dindune, A., Valdniece, D., Kazlauskiene, V., Miškinis, J., Šalkus, T., Orliukas, A., Baltrunas, D. XPS and Mössbauer Spectroscopy of LiFePO4 and LiFePO4/C Ceramics. In: FM&NT 2015: Functional Materials and Nanotechnologies: Abstract Book, Lithuania, Vilnius, 5-8 October, 2015. Vilnius: 2015, pp.72-72. ISBN 978-609-459-590-5.

Publication language
English (en)
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