Institute of Nanomaterials Research and Innovation for Energy (IN-RIE), Research Network of NANOTEC-KKU (RNN), Khon Kaen University, Khon Kaen 40002, Thailand.
Phys Chem Chem Phys. 2020 Mar 14;22(10):5439-5448. doi: 10.1039/c9cp06165g. Epub 2020 Feb 4.
Layered-layered composite (xLiMnO·(1 -x) LiMO, M = Mn, Ni, Co, and Fe) cathode materials have attracted much attention as cathodes for high energy density lithium ion batteries. However, these materials are structurally unstable resulting from complicated phase transformation mechanisms during cycling. Additionally, the complex structural characteristics and structural stability of these materials largely depend on their preparation methods. Studying the correlation between multiscale structural properties and preparation methods is important in the development of layered-layered composite cathode materials. In this work, 0.5LiMnO·0.5LiCoO composite materials were prepared with different heating and cooling rates with a maximum temperature of 600 °C. The structural properties of the 0.5LiMnO·0.5LiMO composite materials were investigated using combined in situ X-ray absorption spectroscopy (XAS), in situ X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high resolution transmission electron microscopy (HRTEM) techniques. Heating and cooling rates have no significant effect on either the crystal or local atomic structures of the prepared samples. However, the microstructure was critically important for its impact on electrochemical properties.
层状-层状复合材料（xLiMnO·（1-x）LiMO，M=Mn、Ni、Co 和 Fe）作为高能密度锂离子电池的正极材料受到了广泛关注。然而，这些材料在循环过程中由于复杂的相变机制而结构不稳定。此外，这些材料的复杂结构特征和结构稳定性在很大程度上取决于其制备方法。研究多尺度结构特性与制备方法之间的相关性对层状-层状复合材料正极材料的发展非常重要。在这项工作中，采用不同的升温速率和降温速率（最高温度为 600°C）制备了 0.5LiMnO·0.5LiCoO 复合材料。采用原位 X 射线吸收光谱（XAS）、原位 X 射线衍射（XRD）、场发射扫描电子显微镜（FESEM）和高分辨率透射电子显微镜（HRTEM）技术对 0.5LiMnO·0.5LiMO 复合材料的结构性能进行了研究。升温速率和降温速率对制备样品的晶体和局部原子结构没有显著影响。然而，微观结构对电化学性能有重要影响。
