Synthesis and characterization of nano-lithiated metal oxides

Nano sized Lithiated Manganese oxide (Li2Mn2O 4) and Lithiated Nickel Oxide (Li2NiO2) was synthesized using hydrothermal and co-precipitation method in presence of PVP. The synthesis of Li2Mn204 required the use of hydrogen peroxide as a reducing agent. However Lithiated Cobalt Oxide (LiCoO2 ) was prepared by only co-precipitation method. Its synthesis required the use ammonium persulfate as a reducing agent. Characterization of the synthesized material was carried out by Elemental Analysis, X-Ray Diffraction (XRD), Thermal Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA), Infra Red Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Nano Zeta Sizer. SEM analysis showed that the Li2Mn2O4 prepared by hydrothermal method and co precipitation method is made of spherical nanoparticles with size ranging from 100nm-250nm. X-ray revealed that Li2Mn 2O4 prepared by hydrothermal method was amorphous with substantial amount of unreacted PVP in it. The amorphous sample crystallizes then to crystalline Li2Mn2O4 when heated to higher temperatures. The high temperature allowed the removal of unreacted PVP. These observations were all supported by data from DTA and TGA. In co-precipitation method, the prepared sample was also characterized as amorphous Li2Mn 2O4 but it did not show any unreacted pvp mixed with it. The amorphous Li2Mn2O4 sample becomes crystalline Li2Mn2O4 when heated. The Li2Mn 2O4 was also prepared using the exact same technique but without PVP. The SEM micrographs of the sample prepared without PVP did not show any uniformity in particle size and shape distribution.;Lithiated Cobalt oxide synthesized using PVP led to uniform spherical nano particles with size in the 100nm-200nm range. The prepared sample contains some unreacted PVP.X-Ray analysis showed the prepared sample to be amorphous LiCoO2 that changes to crystalline LiCoO2 when heated to higher temperature. LiCoO2 was also prepared using the exact same technique but without PVP. The SEM micrographs of LiCoO2 without PVP did not show any uniformity in particle size and shape distribution, it lost homogeneity.;Lithiated Nickel Oxide synthesized using PVP in both methods led to uniform spherical nano particles with sizes in the 200-300nm range. The prepared sample contained some unreacted PVP. X-Ray analysis showed that in both methods, Li2NiO2 was prepared. The prepared amorphous Li 2NiO2 crystallizes into crystalline Li2NiO 1.5 when heated to higher temperature. The Li2NiO2 was also prepared without PVP and its SEM data was compared with nano zeta sizer data. It shows particle size for all lithiated metal oxides using PVP in nano range. The results from our study suggest that clean, uniform and homogeneous nanoparticles can be prepared using a simple, room temperature, non-expensive co-precipitation and hydrothermal method in presence of PVP.