Electrochemical behaviour of surface modified SiO2-coated LiNiO2 cathode materials for rechargeable lithium-ion...

Pristine and SiO2-coated on layered LiNiO2 nanoparticles were synthesized by polymeric sol gel process using metal nitrate precursors at 600 degrees C for 10 h. Effect of SiO2 coating on the structure and electrochemical properties of the LiNiO2 cathode material was investigated by using XRD, SEM, Cyclic voltammetry and Charge-discharge techniques. X-ray powder diffraction analysis of SiO2-coated LiNiO2 revealed that the coating did not affect the crystal structure and the R-3m space group of the cathode materials compared to uncoated LiNiO2. Surface morphology of LiNiO2 and silica coated LiNiO2 powder materials were characterized by using SEM studies. The galvanostatic charge/discharge studies of the pristine and silica coated LiNiO2 positive materials were found at 0.5-C rate in the potential range between 3-4.5 V, Silica coated positive electrode materials have improved charge/discharge capacities. Cyclic voltammetry studies have revealed that, short range deintercalation/intercalation process of Li+ ions and the 2 wt.% relatively narrower peaks with less peak separation. 2 wt.% of SiO2-coated LiNiO2 positive material met the structural stability, high reversible capacity and high electrochemical performances.