Preparation of layered oxide Li(Co1/3Ni1/3Mn1/3)O2 via the sol-gel process

Abstract To obtain homogenous layered oxide Li(Co 1/3 Ni 1/3 Mn 1/3 )O 2 as a lithium insertion positive electrode material, the sol-gel process using citric acid as a chelating agent was applied. The material Li(Co 1/3 Ni 1/3 Mn 1/3 )O 2 was synthesized at different calcination temperatures. XRD experiment indicated that the layered Li(Co 1/3 Ni 1/3 Mn 1/3 )O 2 material could be synthesized at a lower temperature of 800°C, and the oxidation state of Co, Ni, and Mn in the cathode confirmed by XPS were +3, +2, and +4, respectively. SEM observations showed that the synthesized material could form homogenous particle morphology with the particle size of about 200 nm. In spite of different calcination temperatures, the charge-discharge curves of all the samples for the initial cycle were similar, and the cathode synthesized at 900°C showed a small irreversible capacity loss of 11.24% and a high discharge capacity of 212.2 mAh·g −1 in the voltage range of 2.9-4.6 V.