New solid-state synthesis routine and electrochemical properties of calcium based ceramic oxide battery materials for lithium battery applications

Single phase LiCo1-xCaxO2 (x=0.0, 0.1, 0.2, 0.3 and 0.5) cathode materials for lithium-ion batteries have been synthesized by a simple low-temperature solid-state routine at 600 degrees C. The samples were characterized and tested by means of TG/DTA, XRD, TEM, SEM with EDAX and electrochemical studies. Phase transformations were identified for LiCo0.9Ca0.1O2, from TG/DTA analysis. Lattice constants determined from XRD are found to vary with the composition. SEM/TEM photographs of the samples have shown defined facets. Different compositions of synthesized oxide materials were explored by using SEM with EDAX analysis. The substitution of Co with Ca, in LiCo0.8Ca0.2O2, has yielded better cycling results compared to all other materials revealed through charge-discharge studies. (c) 2006 Elsevier B.V. All rights reserved.