Synthesis by Solid-state Reaction and Characterise of Li_(1.02)Co_xCr_yMn_(2-x-y)O_4

The spinel Li1.02CoxCryMn2-x-yO4 as a cathode of lithium ion secondary battery was synthesized by a solid-state method. The influences of the different Cr and Co content in the LiMn2O4 on phase constitution and structure, lattice parameters and electrochemical properties were investigated. The spinel structure was kept still with inserting a small amount of Cr and Co to Li1.02Mn2O4. The Jahn-Teller distortion and the Mn3+ disproportionation reaction were restrained efficiently. With the substitution content of Cr and Co increased, the lattice parameters of Li1.02Mn2O4 decreased, while specific surface area was increased, and the specific capacity of the cell was improved. In addition, the initial capacity was decreased, but the cycle performance of materials was improved obviously.