Cathodic behaviour of NiO-coated Li(Ni1/2Mn1/2)O2

摘要: Abstract The compound, Li(Ni 1/2 Mn )O 2 was prepared by the mixed hydroxide method at 950 °C in air. It coated with 3 and 6 wt.% NiO solution heat treated 450 °C compounds were characterized X-ray diffraction, SEM, TEM, BET surface area density. Cyclic voltammmetry of bare NiO-coated showed redox processes 3.69–3.95 V corresponding to couple Ni 2+/3+/4+ . Galvanostatic charge–discharge cycling carried out 30 mA g −1 up 70 cycles voltage ranges, 2.5–4.3 2.5–4.5 V versus Li room temperature. 10th cycle discharge capacities for are 140 ± 3 mAh g which stable 20–30 after capacity-fading occurs. 6% compound performs better only 11% capacity loss 70th cycle. In range 2.5–4.5 V, third 175 ± 5 mAh g 3% compounds, but starts from fifth onwards. a 165 ± 3 mAh g during 3–30 it degraded, ∼9%, Thus, NiO-coating suppresses not eliminates coulombic efficiency all cases >98%. DSC on cathodes charged-state (4.3 V) show that exothermic decomposition NiO-compound occurs 300 307 (±2) °C, respectively.