Characterization of Na Li NiMnO as a positive electrode material for lithium-ion batteries.

The relationship between the charge-discharge properties and crystal structure of Na Li NiMnO (0.010 ≤ ≤ 0.013, 0.16 ≤ ≤ 0.20) has been investigated. Li/Na Li NiMnO cells exhibit gradually sloping initial charge and discharge voltage-capacity curves. The initial charge capacity increased from 171 mA h g for thermally-treated NaLiNiMnO to 226 mA h g for NaLiNiMnO with an increase in the Li content. The initial maximum discharge capacity was 252 mA h g in the case of NaLiNiMnO between 4.8 and 2.0 V at a fixed current density of 15 mA g (0.06C) at 25 °C. The predominance of the spinel phase leads to the high initial discharge capacity of NaLiNiMnO. This study shows that chemical lithiation using LiI is effective to improve the electrochemical properties.