关键词: 锂离子电池, 正极材料, LiMn₂O₄, 容量衰减, 掺杂

Abstract: To improve the specific of lithium ion batterise, main effort should be directed toward the synthesis of new positive electrode materials, i.e.. various lithiated oxide that could reversibly intercalate one Li atom per 3d-metal atom at about 4 V %versus% Li. Spinel lithium manganese oxide(LiMn₂O₄) attracted interest because of its economical and environmental advantages compared to other lithiated transition metal oxide such as lithium cobalt oxide(LiCoO₂) or lithium nickel oxide(LiNiO₂). However, efforts to substitute LiMn₂O₄ for LiCoO₂, in commercial Li-ion batteries have not been successful due to the rapid capacity fade upon cycling. This capacity fading has been suggested to be due to spinel dissolution, the Jahn-Teller effect and lattice instability. In the paper, doped LiMn_2-xCr_xO₄ compounds(0<x≤0.2) were synthesized. Though LiMn_2-xCr_xO₄ has a lower specific discharge capacity than that of LiMn₂O₄, it show the best cycle performance, the improvement of cycle performance is attributed to the stabilization of the spinel structure.

Key words: Lithium ionic batteries, Cathode material, LiMn₂O₄, Capacity decrease, Doping