Preparation and characterization of LiMnxFe1-xPO4(0 < x < 0.5) cathode materials

• Main Authors: Yue-Lun Wu, 吳岳倫
• Other Authors: She-huang Wu
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/15295776584358761825

碩士 === 大同大學 === 材料工程學系(所) === 97 === In this study, the olivine structure LiFePO4 and Mn2+-substituted LiMnxFe1-xPO4 (0 ≤ x ≤ 0.5) powders were prepared which by a solution method. The crystalline structures, compound composition, mean particle size, carbon content and morphology of the synthesized samples were investigated with XRD, ICP-OES, PSA, EA, and SEM. The electrochemical properties of synthesized samples were studied by capacity retention study and cyclic voltammetry. The un-substituted LiFePO4 shows higher reversible capacity and better rate capability than Mn2+-substituted samples, though Mn2+-substitution may improve the reversibility of the Fe3+/Fe2+ redox reaction. It may be caused by the decrease in diffusion coefficient of Li+ ions by Mn2+-substitution.