Synthesis and electrochemical properties of LiNi0.8Co0.15Al0.05O2 prepared from the precursor Ni0.8Co0.15Al0.05OOH

LiNi0.8Co0.15Al0.05O2 cathode material for lithium-ion batteries is synthesized by sintering the precursor Ni0.8Co0.15Al0.05OOH, which is prepared from the corresponding metal sulphates solution by a co-oxidation-controlled crystallization method. The effects of calcination temperature and time on the electrochemical performance of the material are investigated on the basis of TG-DSC analysis. XRD analyses show that the powders obtained by calcination at 700 °C for 6 h have the best-ordered hexagonal layer structure. SEM images show that these powders are spherical particles with diameter in the 5–12 μm range. The XPS measurement and the chemical titration display that Ni ions of these powders are in the form of Ni3+. The charge–discharge tests demonstrate that these powders have the best electrochemical properties, with an initial discharge capacity of 196.8 mAh g−1 and capacity retention of 96.1% after 50 cycles when cycled at a current density of 0.2 C between 2.8 and 4.3 V. Besides, these powders have also exhibited excellent rate capability and high-temperature performance.

► The spherical precursor Ni0.8Co0.15Al0.05OOH was prepared by a co-oxidation-controlled crystallization method.
► LiNi0.8Co0.15Al0.05O2 powders synthesized by sintering Ni0.8Co0.15Al0.05OOH at 700 °C for 6 h have the best-ordered hexagonal layer structure and the least cation mixing.
► LiNi0.8Co0.15Al0.05O2 powders synthesized by sintering Ni0.8Co0.15Al0.05OOH at 700 °C for 6 h have the best electrochemical properties.
► Ni ions of LiNi0.8Co0.15Al0.05O2 powders are in the form of Ni3+.