尖晶石LiMn2O4的表面改性研究

研究了表面包覆TiO2的尖晶石LiMn2O4.XRD、SEM研究结果表明:经包覆处理后的材料仍为尖晶石结构,粒径均匀.电化学性能测试表明:表面包覆可很好地抑制LiMn2O4材料在电解液中Mn的溶解,提高了循环性能.经包覆处理后的样品的电化学反应阻抗增加.2%包覆量的样品的初始容量为114 mAh/g,常温下,20次循环后容量保持率为100%,100次循环后容量保持率为95%.

Study on the surface modification for spinel LiMn2O4

TiO_2-coated spinel LiMn_2O_4 was studied. The XRD and SEM analysis showed that the modified material had the (appearance) of full crystal,it's structure was still the cubic spinel,it's grain distribution was uniform. The electrochemical analysis of these samples showed that the TiO_2-coated spinel LiMn_2O_4 cathode materials could decrease the amount of Mn dissolving in the (electrolyte) and had better cyclic performance.It was found that the charge transfer resistance of LiMn_2O_4 was less than that of TiO_2 coated LiMn_2O_4.The initial capacity of 2% TiO_2-coated spinel LiMn_2O_4 was 114 mAh/g.The ratio of capacity amount of TiO_2-coated spinel LiMn_2O_4 was 100% after 20 cycles and it was 95% after 100 cycles at room temperature.