Influence of Y~(3+) on Structure and Electrochemical Property of LiMn_2O_4

• 出 处: Journal of Rare Earths
• 发表日期: 2005年04期

Li_(1.02)Y_xMn_(2-x)O_4(x=0, 0.005, 0.01, 002, 0.04, 0.1) were prepared by solid state reaction method with raw materials Li_2CO_3, electrolytic MnO_2 and Y_2O_3. Li_(1.02)Y_xMn_(2-x)O_4 with different Y~(3+) contents have good crystal structure. Y~(3+) doping makes the lattice parameter and crystal volume small. Cyclic voltammogram testing result shows that a small quantity of Y~(3+) doping has no influence on the Li~+ deinsertion-insertion process, but Y~(3+) doping decreases the interacting force among Li~+, and then availably avoids the energy level splitting. The electrochemical property testing indicates that the initial discharge capacity at (x=0.02) is 117.2 mAh·g~(-1) and remains 969% with 113.6 mAh·g~(-1) after 20 cycles, which explains that Y~(3+) doping effectively restricts Jahn-Teller effect and stabilizes the crystal structure. AC analysis shows that conductivity of the samples is clearly improved due to Y~(3+) doping.

Li_ (1.02) Y_xMn_ (2-x) O_4 (x = 0, 0.005, 0.01, 0.02, 0.04, 0.1) were prepared by solid state reaction method with raw materials Li_2CO_3, electrolytic MnO_2 and Y_2O_3. Li_ (1.02) Y_xMn_ (2-x) O_4 with different Y ~ (3+) contents have good crystal structure. Y ~ (3+) doping makes the lattice parameter and crystal volume small. Cyclic voltammogram testing result shows that a small quantity of Y ~ (3 + doping has no influence on the Li ~ + deinsertion-insertion process, but Y ~ (3+) doping decreases the interacting force among Li ~ +, and then availably avoids the energy level splitting. The capacity (x = 0.02) is 117.2 mAh · g ~ (-1) and remains 969% with 113.6 mAh · g ~ (-1) after 20 cycles, which explains that Y ~ (3+) doping makes restricts Jahn-Teller effect and stabilizes the crystal structure. AC analysis shows that the conductivity of the samples is clearly improved due to Y ~ (3+) doping.