Synthesis of lithium LiNi1−yCoyO2 from lithium carbonate, nickel oxide and cobalt carbonate and their electrochemical properties

LiNi1−yCoyO2 (y = 0.1, 0.3 and 0.5) were synthesized by solid state reaction method at 800 °C and 850 °C from Li2CO3, NiO and CoCO3 as starting materials. The electrochemical properties of the synthesized LiNi1−yCoyO2 were investigated. As the content of Co decreases, particle size decreases rapidly and particle size gets more homogeneous. When the particle size is compared at the same composition, the particles synthesized at 850 °C are larger than those synthesized at 800 °C. Among LiNi1−yCoyO2 (y = 0.1, 0.3 and 0.5) synthesized at 850 °C, LiNi0.7Co0.3O2 has the largest intercalated and deintercalated Li quantity Δx at the first charge–discharge cycle, followed in order by LiNi0.9Co0.1O2 and LiNi0.5Co0.5O2. LiNi0.7Co0.3O2 synthesized at 850 °C has the largest first discharge capacity (142 mAh/g), followed in order by LiNi0.9Co0.1O2 synthesized at 850 °C (113 mAh/g), and LiNi0.5Co0.5O2 synthesized at 800 °C (109 mAh/g).