cathode material for lithium ion batteries;
LiCoyMnxNi1-x-yO2;
the valence of Mn in LiCoyMnxNi1-x-yO;
optimum preparation temperature;
electrochemical property;
D O I:
10.1016/S0378-7753(00)00407-9
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
The preparation of LiCoyMnxN1-x-yN1-x-yO2 from LiOH . H2O, Ni(OH)(2) and gamma-MnOOH in air was studied in detail. Single-phase LiCoyMnxN1-x-yO2 (0 less than or equal to y less than or equal to 0.3 and x = 0.2) is obtained by heating at X30-900 degrees C. The optimum heating temperatures are 850 degrees C for y = 0-0.1 and 900 degrees C for y = 0.2-0.3. Excess Lithium (1 less than or equal to z less than or equal to 1.11 for y = 0.2) and the Co doping level (0.05 less than or equal to y less than or equal to 0.2) do not significantly affect the discharge capacity of LizCoyMn0.2Ni0.8-yO2. The doping of Co into LiMn0.2Ni0.8O2 accelerates the oxidation of the transition metal ion, and suppresses partial cation mixing. Since the valence of the manganese ion in LiMn0.2Ni0.8O2 is determined to be 4, the formation of a solid solution between LiCoyNit-yO2 and Li2MnO3 is confirmed. (C) 2000 Elsevier Science S.A. All rights