(浙江大學 材料科學與工程系， 杭州 310027)
摘 要: 與未摻雜的尖晶石LiMn2O4進行比較，用固相混合合成法制得的結(jié)晶良好的尖晶石Li1.05Ni0.05Mn1.9O4正極材料在室溫和55 ℃下的循環(huán)性能都能得到較大改善， 首次放電容量在室溫和55 ℃分別保持理論容量的92.6%和91.5%。 在常溫條件下， 以0.5 C充放電倍率循環(huán)50次， 容量保持為首次放電容量的95.3%。 采用非原位X射線衍射的方法對不同脫鋰狀態(tài)的Lix［Li0.05Ni0.05Mn1.9］O4 (0.1<x<1)試樣進行了結(jié)構(gòu)分析。 結(jié)果表明： Li、 Ni的協(xié)同摻雜明顯減小了晶格參數(shù)的變化， 穩(wěn)定了試樣的結(jié)構(gòu)及改善了電池循環(huán)性能。
關(guān)鍵字: 鋰離子電池； 正極材料； Li1.05Ni0.05Mn1.9O4；非原位X射線衍射； 晶格參數(shù)
cathode material during Li extraction
TU Jiang-ping
（ 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
