Sol-Gel法合成LiMn_2O_4及电化学研究

Study on the Electrochemical Properties of LiMn_2O_4 Prepared by Sol-gel

用溶胶-凝胶法在300℃、空气中制备了LiMn_2O_4粉体,初步讨论了LiMn_2O_4的生成机制,低温制备的样品含有少量的杂相Mn_2O_3,扫描电镜观察及粒度测定表明:粉体粒度为0.5μm左右,粒度分布均匀,比表面测定也证实样品为多孔状,这些都使得样品具有良好的动力学性能.将此样品作为正极,锂为负极,电解液为1mol LiCLO_4(PC:EC:DME=1:1:2),组装成实验电池,测得LiMn_2O_4的可逆比容量为125mAh/g,样品循环充放电性能良好.

The LiMn2O4 powder was prepared by Sol-gel method at 300℃. The morphology and size of grain were determined by XRD and SEM. Coin cells have been used to test the cycleability and characteristics the materials with 1 mol LiClO4 / PC-EC-DME electrolyte. Reversible capacity has been demonstrated for 10 cycles with 125mAh/g in the range 4.2V to 3.4V cycling cut off voltages without any important capacity loss.