嵌锂正极材料LixMn_3-xO₄和LiFeO₂的制备和物性研究

Synthesis and Study on Physical Properties of Li-Inserted Cathode Materials LixMn_3-xO₄ and LiFeO₂

摘要: 本文采用溶胶凝胶法制备了Li_xMn_3-xO₄(X = 0.7, 1.0, 1.2, 1.4, 1.6)和LiFeO₂锂离子电池正极材料，并对其结构、磁性、电化学性能进行了研究。实验发现，Li_xMn_3-xO₄系列样品呈现尖晶石结构，室温下显示顺磁特性，x = 1.2的样品首次充放电容量分别为58.16 mA h/g和29.47 mA h/g，LiFeO₂样品为α-NaFeO₂型铁氧体结构，空间群为Fm3m，室温下呈现软磁特性，首次充放电容量为80.95 mA h/g和38.50 mA h/g。本文详细的分析了系列样品的结构、磁性与电化学性能之间的关系，为提高嵌锂正极材料容量、稳定性以及充放电能力等性能提供了实验依据。

Abstract: In this work, lithium ion battery cathode material Li_xMn_3-xO₄(X = 0.7, 1.0, 1.2, 1.4, 1.6) and LiFeO₂ were synthesized by a sol-gel method. At the same time, the structure, magnetism and electro-chemical performance of samples were studied. The results showed that Li_xMn_3-xO₄ were spinel structure and showed paramagnetic properties at room temperature. The initial charge-discharge capacities of sample with x = 1.2 were 58.16 mA∙h/g and 29.47 mA∙h/g. LiFeO₂ sample with space group Fm3m exhibited a α-NaFeO₂ ferrites structure, show soft magnetic properties at room temperature. The initial charge-discharge capacities of LiFeO₂ sample were 80.95 mA∙h/g and 38.50 mA∙h/g. The relationship between the structure, the magnetism and electrochemical performance of series samples was analyzed deeply, which provided experimental basis for improving the capacity, stability and charge-discharge capacity properties of lithium cathode material.