Study on the electrochemical performance of high-cycle LiMg0.08Mn1.92O4 cathode material prepared by a solid-state combustion synthesis
Study on the electrochemical performance of high-cycle LiMg0.08Mn1.92O4 cathode material prepared by a solid-state combustion synthesis
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DOI：
10.1016/j.ceramint.2014.03.077
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发表时间：
2014-08
影响因子：
5.2
通讯作者：
Mingwu Xiang;Liqing Ye;Cancan Peng;Zhongwei Lei;Bai Hong-li;Changwei Su;Junming Guo
中科院分区：
文献类型：
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作者：
Mingwu Xiang;Liqing Ye;Cancan Peng;Zhongwei Lei;Bai Hong-li;Changwei Su;Junming Guo
采用固相燃烧法在不同煅烧温度下合成了LiMg0.08Mn1.92O4正极材料。用X射线衍射（XRD）分析了样品的晶体结构，用扫描电子显微镜（SEM）观察了样品的形貌。所有煅烧材料均被鉴定为尖晶石结构的LiMn2O4。在500 °C、600 °C和700 °C下合成的材料均为单相，而在800 °C和900 °C下合成的材料中可检测到Mn3O4杂质相。随着煅烧温度的升高，粉体的平均粒径增大。通过恒电流充放电测试、循环伏安（CV）和电化学阻抗谱（EIS）研究了两段煅烧温度对LiMg0. 08Mn1. 92O4材料电化学性能的影响。结果表明，Mg的掺杂提高了材料的结构稳定性。在600 °C和700 °C下煅烧的LiMg0.08Mn1.92O4材料表现出优异的电化学性能，其首次放电比容量分别为101.3 mAh g− 1和107.6 mAh g−1，在0.2 C下40次循环后的容量保持率分别为98.1%和94.3%。
LiMg0.08Mn1.92O4cathode materials were prepared by a solid-state combustion synthesis at different calcination temperatures. The crystal structure was characterized by X-ray diffraction (XRD) analysis and the morphology was observed by scanning electron microscopy (SEM). All the calcined materials were identified as the spinel structure of LiMn2O4. The materials synthesized at 500 °C, 600 °C and 700 °C were single phase, while Mn3O4impurity phases can be detected in the other materials synthesized at 800 °C and 900 °C. The average particle size increased with the increase of calcination temperature. The effect of two-stage calcination temperature on the electrochemical properties of the LiMg0.08Mn1.92O4materials was studied by galvanostatic charge/discharge tests, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. Results showed that the structural stability of the materials was improved due to Mg-doping. The LiMg0.08Mn1.92O4materials calcined at 600 °C and 700 °C demonstrated excellent electrochemical performance with an initial discharge specific capacity of 101.3 mAh g−1and 107.6 mAh g−1, and their capacity retention was 98.1% and 94.3% after 40 cycles at 0.2 C, respectively.