Structure and electrochemical performance of LiFexNi1-xO2 (0.00 ≤ x ≤ 0.20) cathode materials for rechargeable lithium-ion batteries

Abstract

LiMn2O4 and vanadium-substituted LiVxMn2 − xO4 (x = 0.05, 0.10 0.15 and 0.20) cathode materials were synthesized by sol–gel method using aqueous solutions of metal nitrates and tartaric acid as chelating agent at 600 °C for 10 h. The structure and electrochemical properties of the synthesized materials were characterized by using X-ray diffraction, SEM, TEM and charge–discharge studies. X-ray powder diffraction analysis was changed in lattice parameters with increasing vanadium content suggesting the occupation of the substituent within LiMn2O4 interlayer spacing. TEM and SEM analyses show that LiV0.15Mn1.85O4 has a smaller particle size and more regular morphological structure with narrow size distribution than LiMn2O4. It is concluded that the structural stability and cycle life improvement were due to many factors like better crystallinity, smaller particle size and uniform distribution compared to the LiMn2O4 cathode material. The LiV0.15Mn1.85O4 cathode material has improved the structural stability and excellent electrochemical performances of the rechargeable lithium ion batteries.