Comparative experiment on layered Li(Ni_1/3Co_1/3Mn_1/3)O₂ as the alternative material for LiCoO₂

The characteristics and electrochemical properties of the layered Li(Ni_1/3Co_1/3Mn_1/3)O₂ have been investigated by using the X-ray diffraction (XRD), scanning electron microscopy (SEM), and cyclic voltammograms (CV). The Li(Ni_1/3Co_1/3Mn_1/3)O₂ powders were synthesized by coprecipitation method. The as-synthesized Li(Ni_1/3Co_1/3Mn_1/3)O₂ has well-shaped crystals with a uniform particle size distribution at ~500 nm. A reversible discharge capacity of 165 mAh/g at a current of 40 mA/g between 2.7-4.35 V, with stable cycling performance has been obtained. Moreover, the discharge capacity rises up to 190 mAh/g, when the cutoff voltage increases to 4.6 V. The excellent cycling performance at a higher cutoff operating voltage (up to 4.8 V) could be attributed to the well-retention of the microstructure of synthesized Li(Ni_1/3Co_1/3Mn_1/3)O₂ powders. Comparatively, LiCoO₂ suffered structure degradation at a higher cutoff voltage. However, the high rate properties of Li(Ni_1/3Co_1/3Mn_1/3)O₂ is not as good as LiCoO₂, so its electrical conductivity must be improved.