Electrochemical properties of LiMn2O4 films produced by combustion reaction

• Published in: Solid state sciences 2004-12, Vol.6 (12), p.1353-1358
• Main Authors: FONSECA, Carla Polo, PALLONE, Eliria M. J. A, NEVES, Silmara
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Crystalline state (including molecular motions in solids); Exact sciences and technology; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Theory of crystal structure, crystal symmetry; calculations and modeling; Transport properties of condensed matter (nonelectronic)
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2004.07.014

Lithium manganese oxide powders were prepared via combustion reaction. Structural characterization of the powder using X-ray diffraction and scanning electron microscopy confirmed the formation of a LiMn2O4 nanosized powder. LiMn2O4 films were prepared by spin coating using 80 wt% of oxide, 15 wt% of polyaniline (PAni) as an electronic conductor and 5 wt% of polyvinylidene (PVDF) as a binder in N.N.-dimethyl acetamide. A Coulombic efficiency of 96% confirmed the electrochemical stability of the composite. The variation in impedance as a function of the lithium intercalation/deintercalation process reflected the interaction between the oxide and/or polyaniline particles at a high frequency range, and a diffusion tendency was observed at medium and low frequency ranges. The capacity values of the composite electrodes relative to the LiMn2O4 mass were 178.6/177.5 and 145/140 mAh g-1 for the first and 25th charge/discharge cycles, respectively.