Ceramics-Silikáty 54, (1) 38 - 46 (2010) |
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SYNTHESIS AND CHARACTERIZATION OF Li[Mn2-x Mgx]O4 (x = 0.0-0.3) PREPARED BY SOL-GEL SYNTHESIS
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Singh Priti 1, Sil Anjan 2, Nath Mala 1,
Ray Subrata 2
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1 Department of Chemistry, Indian Institute of Technology Roorkee,
Roorkee 247667, India
2 Department of Metallurgical and Materials Engineering,
Indian Institute of Technology Roorkee, Roorkee 247667, India
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Keywords: Ceramic oxide, Sol-gel technique, X-ray diffraction, Thermogravimetric analysis
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XRD analysis of Li[Mn2-x Mgx]O4 (x = 0.0, 0.05, 0.1, 0.15, 0.2, 0.25 and 0.3) powders synthesized by a sol-gel process, shows single phase cubic spinel structure having space group Fd3m up to x = 0.25. When Mg content increases to x = 0.3, second phase with space group P4332 appears. TG (Thermo Gravimetric) analysis shows the oxygen loss from the structure begins at lower temperature as the Mg content increases. DTA (Differential Thermogravimetric Analysis) shows stabilization of orthorhombic LiMnO2 and tetragonal Mn3O4 by Mg doping. Number of vibrational bands increase as the Mg
content increases which indicate that the ordering of spinel structure increases and the reduction of the space group from Oh7 (Fd3m) to O7 (P4332). The discharge capacity of 122 mAh g-1 has been observed for LiMn2O4 and it decreases when the
increase in Mg content. In Mg doped samples Li[Mn2-xMgx]O4, step corresponding to cubic-cubic transition decreases and gets completely removed for x = 0.25. |
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