Abstract: Modified spinel lithium manganese oxides LiMn_2-x-yCo_xLa_yO_4-zCl_z and LiMn_2-x-yCo_xLa_yO_4-zCl_z/C composite cathodes for lithium-ion batteries were prepared by the solid-state method. The structure and morphology of as-prepared cathode materials were characterized by XRD and ESEM. The electrochemical performances of the materials were tested by constant-current cyclic testing and electrochemical impedance spectroscopy. The results showed that the modified materials LiMn_2-x-yCo_xLa_yO_4-zCl_z and LiMn_2-x-yCo_xLa_yO_4-zCl_z/C were the simple spinel phase. Electrochemical tests showed that the material obtained by adding glucose as carbon additive gave an enhanced performance in terms of improved practical discharge capacity and good cyclability. The specific capacity was 126.5mAh·g^-1 at the first cycle. The cell was cycled for 50 cycles with an average specific capacity of about 123.5mAh·g^-1, the degrading rate of which was less than 2.4%.

Key words: lithium-ion batteries, cathode material, spinel, coated-carbon