Improved the Electrochemical Performance of LiCe1−xNixO2 Cathode Material for Rechargeable Lithium Ion Battery

Abstract

Cerium substituted LiCe(1-x)Ni(x)O2 (0.00 < X < 0.20) (Ce = 0.00 < X < 0.20) nano-particles were synthesized by sol-gel method using nitrate as precursor at 800 degrees C for 12 hrs. XRD studies were revealed a well defined layer structure and a linear variation of lattice parameters with the addition of Cerium confirmed phase pure compounds in a rhombohedral structure for all materials. The surface morphological and particles agglomeration changes by the substitution of Cerium in LiNiO2 particles were examined by scanning electron microscope technique and TEM techniques. Ce3+ has prevented Jahn-Teller distortion and contained the NiO6 in LiCe(1-x)Ni(x)O2 through charge transfer from Ce-3d orbital to nearby Ni-3d orbital. The preferential occupation of Ce3+ in the Li sites was decreased the mixing of Ni2+ into the Li sites and improved the electrochemical properties of LiNiO2. The galvanostatic charge/discharge studies using assembled cells were carried out at 0.5 C rates. Cyclic voltammetric studies were carried out in the potential range between 3.5 V and 4.7 V at a scan rate of 0.1 mV s(-1). Electrochemical impedance spectroscopy revealed that, LiCe0.15Ni0.85O2 augmented charge transfer resistance upon cycling. The variations of cerium mixing and hexagonal ordering with the element (increase in R-factor) were favoured the first discharge capacity with the substituted element. LiCe0.15Ni0.85O2 nano cathode materials have superior electrochemical performances, such as, high charge-discharge capacity, high coulombic efficiency, high electrical conductivity and low irreversible capacity loss.