Facile synthesis and electrochemical properties of spherical LiNi0.85−xCo0.15AlxO2 with sodium aluminate via co-precipitation

Spherical nickel rich layer cathode materials (LiNi 0.85− x Co 0.15 Al x O 2 ( x   =   0.02, 0.05 and 0.10), NCA) with excellent electrochemical performance for high energy densities lithium-ion batteries are successfully synthesized by a continuous co-precipitation method. An elaborate design of Al solution with sodium aluminate is successfully adopted, which can efficiently prevent rapid precipitation of Al(OH) 3 and obtain the precipitated precursors. The thermodynamic model is established in the Ni—Co—Al—NH 3 —H 2 O system and investigation of precipitation mechanism is carried out systematically, and the results demonstrate that the spherical LiNi 0.85− x Co 0.15 Al x O 2 can be obtained through this route. Charge and discharge tests show that LiNi 0.85− x Co 0.15 Al x O 2 synthesized has a high initial discharge specific capacity of 208   mAh/g at 0.1   C and a good capacity retention of 90.2% after 200 cycles at 0.5   C between 2.5 and 4.3   V. It is expected that performance of NCA electrodes for advancing lithium-ion batteries could be improved with the new process proposed in this study.