Mn₃O₄锰源中杂质铁对LiMn₂O₄正极材料电性能的影响研究

Study on the Influence of Impurity Iron in Mn₃O₄ Manganese Source on the Electrical Properties of LiMn₂O₄ Positive Electrode Material

摘要: 采用不同杂质铁含量(18 μg/g、78 μg/g、153 μg/g、214 μg/g、306 μg/g)的五种Mn₃O₄作为锰源，通过高温固相法两步烧结将碳酸锂和四氧化三锰合成尖晶石锰酸锂正极材料。经SEM扫描电镜、X射线衍射及电性能循环测试研究杂质铁对锰酸锂正极材料的形貌、结构和电化学性能的影响。结果显示：当杂质铁含量为78 μg/g时，锰酸锂具有良好的尖晶石型三维立体结构，颗粒大小、密度分布都比较均匀，初始充放电容量为125.5 mAh/g、118.9 mAh/g，在经过50循环后容量保持率为76.4%，初始放电容量和循环保持率均为最优结果。

Abstract: The spinel LiMn2O4 cathode materials were synthesized from lithium carbonate and manganous oxide by two-step sintering at high temperature using five kinds of Mn₃O₄ with different impurity iron content (18 μg/g, 78 μg/g, 153 μg/g, 214 μg/g, 306 μg/g) as manganese source. The mor-phology, structure and electrochemical performance of LiMn₂O₄ cathode material were studied by SEM, XRD and electrical performance cycle test. When the content of impurity iron is 78 μg/g, the spinel type three-dimensional structure of lithium manganate is good, and the particle size and density distribution are relatively uniform. The initial charge discharge capacity is 125.5 mAg/g, 118.9 mAg/g, and the capacity retention rate is 76.4% after 50 cycles. The initial discharge capacity and cycle retention rate are both optimal.