Synthesis and electrochemical characterizations of nano size Ce doped LiMn2O4 cathode materials for rechargeable lithium batteries

LiCexMn2-xO4 (x = 0.00-0.10) cathode materials for rechargeable lithium-ion batteries were synthesized by simple sol-gel technique using aqueous solutions of metal nitrates and succinic acid as the chelating agent. The gel precursors of metal succinates were dried in vacuum oven for 10 h at 120 degrees C. After drying, the gel precursors were ground and heated at 900 degrees C. The structural characterization was carried out by X-ray powder diffraction and X-ray photoelectron spectroscopy to identify the valence state of Mn and Ce in the synthesized materials. The sample exhibited a well defined spinet structure and the lattice parameter linearly increased with increasing the cerium contents in LiCexMn2-xO4. Surface morphology and particle size of the synthesized materials were determined by scanning electron microscopy and transmittance electron microscopy respectively. Electrochemical properties were characterized for assembled Li/LiCexMn2-xO4 coin type cells using galvanostatic charge/discharge studies at 0.5C rate and cyclic voltammetry in the potential range between 2.75 and 4.5 Vat a scan rate of 0.1 mV s(-1). Among them cerium doped spinel LiCe0.05Mn1.90O4 has improved structural stability, high reversible capacity and excellent electrochemical performance of rechargeable lithium batteries. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.