Microstructural and electrical properties of Mg substituted Li 4 Ti 5 O 12 synthesized by ceramic method

In this paper the effect of magnesium (Mg) substitution in lithium (Li) site of spinel lithium titanate (Li4Ti5O12, LTO) based materials for anodes of Li-ion batteries (LIBs) is extensively studied. The anode materials based on the formula Li4-xMgxTi5O12(x=0 and 0.2) are synthesized using conventional ceramic route at 850° C for 16h. Their phase formation processes, crystal structures, morphology, elemental analysis, cation distribution and electrical properties were studied using XRD, SEM, EDX, FT-IR and CIS characterization techniques. The XRD studies revealed the exact structure of the material which belonged to cubic spinel structure as part of the space group Fd-3m. The morphological characteristics related to phase and grain size allocation were found using SEM and the grain size was found to be in the range 0.9-1.1 µm. The FT-IR results revealed the oxide lattice structure built of MO6 (M= Li, Mg and Ti) as tetrahedra and octahedra. The electrical impedance studies showed the material (Li3.8Mg0.2Ti5O12) to exhibit excellent conductivity which was found to be 3.8×10−5 S/cm at ambient temperature for frequency ranging from 20 Hz to 1MHz.