Spinel LiMn-2O-4 Cathode Materials Synthesized by the Citric Gel Co-Precipitation Method

摘要

Various wet chemical methods have been applied to prepared spinel LiMn-2O-4 cathode materials for lithium ion battery. However, the reactions of these methods are usually time consuming and/or scale up difficult. In this study, spinel LiMn-2O-4 with various Li/Mn ratios were prepared by a novel co-precipitation method with lithium acetate and manganese acetate as starting materials, citric acid as chelating agent, and ethyl alcohol as solvent. After the precipitates had been calcined at various temperatures, the compositions, crystalline structures, and electrochemical properties of the prepared powders were investigated. Predominant spinel phase was observed in the powders those had been calcined at temperatures ranging between 600 to 850deg C for 4 hr. From the results of capacity retention studies, shown as Fig. 1, it is found that the sample with x = 0.06 exhibits the highest initial discharge capacity among the 750deg C calcined Li-(1+x)Mn-2O-4 samples. It is also found that the 750deg C calcined sample shows the highest initial discharging capacity and the best cycling performance among the 4 hr calcined Li-1.06Mn-2O-4 samples, shown as Fig. 2.