Electrochemical characteristics of Al_2O_3-coated lithium manganese spinel as a cathode material for a lithium secondary battery

摘要

Al_2O_3-coated spinels were investigated with respect to their electrochemical characteristics. A Al_2O_3 coating on commercial LiMn_(2-x) M_xO_4 (Nikki, Japan, M = Zr) was prepared by using the sol-gel method. AA analysis showed that manganese and lithium dissolution occurred during the coating process. XRD patterns show that increase in the lattice parameter of Al_2O_3-coated spinels is related to formation of a solid solution on the surface of active materials. Impedance results revealed that Al_2O_3-coated spinel has electronic resistance. However, The cell performance was enhanced with the Al_2O_3 coating. Al_2O_3 is regarded as a coating material for stable cycling performance.