Conductivities of Layered LiNi0.7Co0.2Fe0.1O2 and Li[Li0.1Ni0.6Co0.2Fe0.1]O2 Materials

New materials based on LiNiCoO2 with some nickel atoms substituted for other metals has become increasingly popular in cathode materials for Li-ion batteries. The purpose of this research was to investigate the kinetic properties of new materials in a way that is independent of electrode composition and electrolyte used [1]. LiNi0.7Co0.2 Fe0.1O2 and Li[Li0.1Ni0.6Co0.2Fe0.1]O-2 was successfully synthesized by a modified combustion method with an annealing temperature at 700 degrees C for 24h. The X-ray diffraction patterns of the materials reveal a single phase hexagonal structure. Impedance spectroscopy measurements were carried out on the pellets from 25 degrees C to 200 degrees C with a 25 degrees C step. The conductivities were obtained via ac impedance spectroscopy. Arrhenius plots of the samples show that the materials have a linear relationship between log sigma and 1000/T. The activation energy of LiNi0.7Co0.2 Fe0.1O2 and Li[[Li0.1Ni0.6Co0.2Fe0.1]O-2 are 0.64 eV and 0.21 eV respectively. Results indicated that the conductivity of Li[[Li0.1Ni0.6Co0.2Fe0.1]O-2 material is higher than LiNi0.7Co0.2 Fe0.1O2 material.