Nanocrystalline LiNi1−xCoxO2 cathode materials prepared by a gel-combustion process

Nanocrystalline LiNi1−xCoxO2 particles with a stable single-phase were synthesized through a nitrate–citrate gel-combustion process, in which nitrate was used as an oxidizing agent, and citric acid as an organic fuel and a chelating agent as well. The characteristics of the as-synthesized cathode materials, such as crystalline size, particle size and initial discharge capacitance, can be effectively controlled by the ratio of metal to citric acid and annealing temperature, with a result of that the suitable ratio of metal to citric acid was 1:6 and the annealing temperature was 600 °C. It was demonstrated that different electrochemical performances of cathode materials for lithium ion cells were obtained with different composition of LiNi1−xCoxO2, and the initial discharge capacitances as much as 188 m Ah g−1 for Ni:Co=7:3, 172 mA h g−1 for Ni:Co=5:5 and 160 m Ah g−1 for Ni:Co=3:7 were achieved, respectively. It is worthy emphasizing that the presented route is a simple, inexpensive and fast one for the synthesis of cathode materials for lithium ion cells.