초록 |
Heat-treatment effects, crystallographic symmetries, chemical compositions, thermal analysis, and electrical properties of the lithium cobalt oxides were studied with slightly varying the mole fractions(i.e. ±0.04mole)of lithium. All the samples were found to have tetragonal symmetries.Applying indirect iodometry, we could verify the mixed valencies of Co and finally determine the nonstoichiometric chemical formulas. The electrical conductivity measurements were performed in the temperature range of 293-673K, and the conductivity values(in -log) of Li+0.96Co2+0.05Co3+0.95 O 1.950 were -5.09(Ω·cm)-1) at 293K and -3.02(Ω·cm)-1 at 293K. |