固相分段法制备锂离子电池正极材料LiMn_2O_4的实验

Preparation of LiMn_2O_4 Lithium-ion Battery Cathode Material by the Multiple Sinter Method

通过L25(55)拉丁正交实验,利用极差分析法对制备LiMn2O4的反应条件进行优化,找出了合成LiMn2O4的合适工艺. 固相分段法制备LiMn2O4的过程中,氧化物的合成反应温度、氧气流量、LiOH的分解反应温度、锂锰摩尔比及恒温时间依次为主要影响因素. LiMn2O4实验电池的电化学测试表明,3 V左右放电平台可达8 h,初始放电比容量为140 mAh/g左右. 从结构化学角度分析了尖晶石型锰酸锂材料的充放电过程和产生Jahn-Teller效应的原因.

The preparation of LiMn2O4 by the solid reaction multiple sinter method was studied, in which the sintered material was smashed, ground and pelleted between two successive sintering steps. The optimum technological condition was obtained through orthogonal experiments by L25(55) and DTA analysis. The result was that the order of factors influencing the electrochemical property of synthesized LiMn2O4 were the third sintering temperature, oxygen flowrate, the second sintering temperature, molar ratio of lithium/manganese, homothermal time in decreasing importance. The electrochemical testing results of LiMn2O4 experimental battery showed that specific discharge capacity reached 140 mA穐/g and the persisting time up to 8 h at 3V-discharge plateau. With the standpoint of structural chemistry, the charge-discharge mechanism of spinel structure of LiMn2O4 material was analyzed and the reason of Jahn-Teller domio effect was also suggested.