Abstract. Designing highly protective and superior electrically conductive coatings from Cobalt-manganese doped/un-doped oxide materials (CMOs) is the main target of this study. The as-prepared nanopowders were synthesized via glycine nitrate process (GNP) at moderate annealing temperature afterword characterized using several techniques including X-rays diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and electrochemical impedance measurements at room temperature. The XRD results revealed a pure phase of spinel structure with particle size range 75-81 nm for the doped CMO samples. SEM micrographs exhibited morphology with fine aggregate of particles. The incorporation of different ions of Cu, Ni, Fe and Na into the CMOs structure showed a significant increase in the diffusivity of ions and remarkable improvement in the crystallinity. AC electrical conductivity was also measured for the compacted pellets after sintering at 850°C using the electrochemical impedance spectroscopy technique at room temperature. From the obtained results it could be concluded that the polarization resistance of pure and modified CMOs samples show similar behavior ranged from 5 to 6 k Ω.

New series of spinel LiNi0.25Fe0.2Mˊ0.05Mn1.5O4 (Mˊ = Cu, Mg or Zn) cathode materials have been purposefully tailored using sol-gel auto-combustion method at low annealing temperature ~ 700°C for 3 h. The XRD analysis showed that all substituted (LNFMO-Mˊ) samples are comported with the main structure of undoped (LNFMO) with crystalline disordered spinel Fd-3m structure. TEM images revealed the octahedron-shape like morphology for the particles and the LNFMO-Zn sample has the widest particle size distribution. EIS spectra evidenced that a typical one semicircle (LNFMO-Mg) was revealed for each cell, suggesting the absence of ionic conductivity contribution. The values of charge transfer resistance (Rct) were equal to 9.3, 6.7, 6.0 and 4.4 kΩ for LNFMO, LNFMO-Cu, LNFMO-Mg indicating that the Zn-doped sample has the fastest kinetic diffusion rate and lowest activation energy of conduction.