(浙江大学 材料科学与工程系， 杭州 310027)
摘 要: 与未掺杂的尖晶石LiMn2O4进行比较，用固相混合合成法制得的结晶良好的尖晶石Li1.05Ni0.05Mn1.9O4正极材料在室温和55 ℃下的循环性能都能得到较大改善， 首次放电容量在室温和55 ℃分别保持理论容量的92.6%和91.5%。 在常温条件下， 以0.5 C充放电倍率循环50次， 容量保持为首次放电容量的95.3%。 采用非原位X射线衍射的方法对不同脱锂状态的Lix［Li0.05Ni0.05Mn1.9］O4 (0.1<x<1)试样进行了结构分析。 结果表明： Li、 Ni的协同掺杂明显减小了晶格参数的变化， 稳定了试样的结构及改善了电池循环性能。
关键字: 锂离子电池； 正极材料； Li1.05Ni0.05Mn1.9O4；非原位X射线衍射； 晶格参数
cathode material during Li extraction
（ Department of Materials Science and Engineering,
Zhejiang University, Hangzhou 310027, China）
Abstract: Li1.05Ni0.05Mn1.9O4 cathode material with spinel structure was synthesized after solid-state mixing. Compared with spinel LiMn2O4, the cyclic stability of Li1.05Ni0.05Mn1.9O4 was improved both at room temperature and 55 ℃. The first discharge capacities of Li1.05Ni0.05Mn1.9O4 are 92.6% and 91.5% of the theoretical capacity at room temperature and 55 ℃. After 50 cycles with 0.5 C charging-discharging rate at room temperature, the capacity is still 95.3% of the first discharging capacity. Ex-situ X-ray diffraction(XRD) was used to analyze the structures of different Li extraction states of Lix［Li0.05Ni0.05Mn1.9］O4 (0.1<x<1). The results indicate that adding Li and Ni ions into LiMn2O4-based compound restrains the change of lattice parameter, stabilizes the structure of the sample and improves the cyclic performance.
Key words: lithium-ion battery; cathode material; Li1.05Ni0.05Mn1.9O4; ex-situ X-ray diffraction; lattice parameter
