Relaxation Phase Analysis of LiMn2O4 Cathode for Secondary Li Ion Battery

摘要

Li-Mn-O system is expected to perform as a favorable electrode material for lithium ion battery due to its low cost, low toxicity and high electric capacity. We firstly extracted all amount of Li electrochemically and inserted Li till x = 0.1 at a rate of 1C in terms of LixMn2O4 electrochemically then stopped the insertion. We measured X-ray diffraction as a function of elapsed time after termination of Li insertion process and investigated phase change of LiMn2O4 material after termination of Li insertion process. From the asymmetric Lorentz peak fitting result of the XRD pattern, it was found that the two phases, Li-rich phase and Li-lean phase, coexist. It is found that the lattice constants of both phases were almost constant and that the amount of Li-lean phase decreased and Li-rich phase increased with the elapsed time.