| 초록 |
We investigate that the effect of Ni and Fe contents on structural and electrochemical properties of O3-type layered Na[Ni0.75xFexMn0.25]O2 (x ¼ 0.4, 0.45, 0.5, and 0.55) in which Mn is fixed at 25%. Asincreasing the Ni contents, the capacities are gradually higher while the capacity retention and thermalproperties are inferior. When Fe contents are increased, by contrast, the electrode exhibits stable capacityretention and satisfactory thermal stability although the resulting capacity slightly decreases. Structuralinvestigation of post cycled electrodes indicate that lattice variation is greatly suppressed from x ¼ 0.5 inNa[Ni0.75xFexMn0.25]O2. This indicates that an appropriate amount of Fe into the Na[Ni0.75xFexMn0.25]O2 stabilizes the crystal structure and this leads to the good cycling performances. |
