S. Vivekanandhan

Synthesis of nanocrystalline LiCoO2 powders by polymeric combustion process: an investigation on the effect of different carboxylic acids as fuel

Abstract Layer-structured nanocrystalline LiCoO2 powders were prepared by polymeric combustion process using metal nitrates and different carboxylic acids as precursors. Three different carboxylic acids named citric, tartaric, and polyacrylic were experimented in order to synthesize ultrafine LiCoO2 nanopowders. The combustion behavior of polymeric intermediates and the formation of LiCoO2 structures were identified through thermogravimetry and differential thermal analyzer (TG/DTA), FTIR, XRD, SEM, and TEM investigations. The correlation between the microstructure of the polymeric intermediates and their thermal degradation profile was observed by their scanning electron micrographs and TG/DTA thermograms. The result found that the effective combustion was occurred only in citric acid (CA)-derived polymeric intermediate due to its porous microstructure, which leads to the formation of phase pure LiCoO2 powders with no organic residual. The TEM analysis reveals that the particle size of the synthesized LiCoO2 powders by the optimized CA-assisted combustion process at 450 °C existed in the range between 30 and 40 nm.

Surface modification and characterization of nanocrystalline LiNi0.5Co0.5VO4 with Dy2O3 by polymeric resin process

Abstract A poly acrylic acid and ethylene glycol mediated polymeric resin process has been demonstrated for the fabrication of functional Dy2O3 layer on the nanocrystalline LiNi0.5Co0.5VO4 surfaces. Polymeric resin helps in the uniform distribution as well as the stabilization of Dy3+ ions on the LiNi0.5Co0.5VO4 surfaces. The thermal degradation of Dy3+ distributed polymeric resin at 500 °C results in the formation of Dy2O3 on the surface of LiNi0.5Co0.5 VO4 particles, which was confirmed by TG/ DTA and FTIR analysis. Excellent homogeneity of the Dy2O3 layer with a controlled thickness on the surface of LiNi0.5Co0.5VO4 has been confirmed by SEM-EDS and TEM analysis. Graphical abstract