Electrochemical performance of cobalt-substituted lithium nickel oxides synthesized from lithium and nickel carbonates and cobalt oxide

Abstract LiNi 1− y Co y O 2 ( y =0.1, 0.3 and 0.5) cathode materials were synthesized by a solid-state reaction method at different temperatures using Li 2 CO 3 as a Li source, NiCO 3 as a Ni source, and Co 3 O 4 as a Co source. The electrochemical properties of the synthesized samples were then investigated. Structures of the synthesized LiNi 1− y Co y O 2 ( y =0.1, 0.3 and 0.5) samples were analyzed, and microstructures of the samples were observed. Voltage vs. x in Li x Ni 1− y Co y O 2 curves for the first and second charge–discharge cycles and intercalated and deintercalated Li quantity Δ x were studied. LiNi 0.9 Co 0.1 O 2 synthesized at 800 °C had the largest first discharge capacity (152 mAh/g) and quite good cycling performance, with a discharge capacity of 146 mAh/g at n =5. It had a discharge capacity fading rate of 1.4 mAh/g/cycle.