Electrochemical modification of spinel oxide materials using lithium solid state electrolyte

• Published in: Solid state ionics Vol. 177; no. 26; pp. 2769 - 2773
• Main Authors: Mateyshina, Yu G., Uvarov, N.F., Ulihin, A.S., Pavlyukhin, Yu T.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31-10-2006
• Subjects: Lithium batteries; Mössbauer spectra; Spinel-framework structure; Spinel-framework structure; Lithium batteries; Mössbauer spectra
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2006.04.025

Solid solutions of the general formula LiFe
1
−
y
Ti
1
−
x
Mn
x
+
y
O
4 (0
≤
x
≤
1; 0
≤
y
≤
1) were prepared and investigated using X-ray diffraction, Mössbauer spectroscopy and electrical measurements. It was shown that substitution of transition elements, first titanium, then iron, for Mn in the spinel structure results in a linear decrease in the lattice parameter. Electrical conductivity increases monotonously with an increase in the concentration of manganese. Conductivity is electronic and proceeds by thermally activated polaron hopping mechanism with the activation energy decreasing with
x
+
y from 0.50 eV to 0.33 eV. Quenched samples have enhanced conductivity and larger lattice parameter, possibly due to the oxygen nonstoichiometry. According to Mössbauer spectroscopy data, the distribution of iron cations changes as a function of the Mn content; for
x
+
y
<
1, almost all the Fe
3+ cations occupy tetrahedral positions. The first experiments were made on the electrochemical charging of Fe-containing spinels under study using solid-state electrochemical cells with oxide anodes and cathodes.