Study on the Preparation of the Cathode Materials for Lithium-Ion Batteries By Multiphase Redox Method

摘要

We report a new method, which is called multiphase redox method, to prepare LiMn_2O_4 cathode material. The precursors of LiMn_2O_4 were synthetized in Mn(OH)_2-H_2O-LiOH solution system by using air, oxygen or KMnO_4 as the oxidant. The oxidation ability of the oxidant has an important influence on the amount of lithium embedding. Meanwhile, the sintering process and the electrochemical performance of the sintered samples are studied as well. The sample sintered at 820 °C for 10 h presents both high discharge capacity and excellent cycle performance. Compared with LiMn_2O_4 prepared by solid-state method, the uniformity in chemical composition of LiMn_2O_4 prepared by multiphase redox method is bettered significantly and the differences in micro-components of LiMn_2O_4 are almost eliminated, thus improving the electrochemical performance of LiMn_2O_4 prepared by multiphase redox method.