Sol-gel synthesis of nano Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials using DL-lactic acid as chelating agent
Sol-gel synthesis of nano Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials using DL-lactic acid as chelating agent
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DOI：
10.1016/j.ceramint.2020.10.205
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发表时间：
2021-01-29
影响因子：
5.2
通讯作者：
Guo, Jianbing
中科院分区：
文献类型：
--
作者：
Chen, Can;Wu, Hongming;Guo, Jianbing
以DL乳酸为螯合剂，采用溶胶-凝胶法制备了富锂正极材料Li1.2Mn0.54Ni0.13Co0.13O2（LMNCO）。通过X射线衍射（XRD）、扫描电子显微镜（SEM）、纳米颗粒分析、充放电测试和电化学分析，研究了pH值对正极材料晶体结构、形貌、粒径和电化学性能的影响。Li1.2Mn0.54Ni0.13Co0.13O2正极材料具有良好的层状结构，由六方相LiMO 2和单斜相Li 2 MnO 3组成，表面光滑，颗粒结晶良好（100-500 nm）。LMNCO-7.0具有比LMNCO-5.5和LMNCO-8.5更小的粒径和更好的电化学性能。LMNCO-7.0的首次放电容量和库仑效率分别为232.31 mAh g（-1）和73.2%。50次循环后，LMNCO-7.0的放电容量下降到194.93mAh g（-1）。LMNCO-7.0正极材料具有较低的电荷转移阻抗和较小的平均准球形粒径，表现出优良的上级放电容量和倍率性能。
Lithium-rich cathode materials Li1.2Mn0.54Ni0.13Co0.13O2 (LMNCO) are prepared by sol-gel method using DL lactic acid as chelating agent. The effect of pH on crystal structures, morphologies, particle sizes, and electrochemical properties of cathode materials are studied by X-ray diffractometry (XRD), scanning electron microscopy (SEM), nanoparticle analysis, charge-discharge tests, and electrochemical analysis. The Li1.2Mn0.54Ni0.13Co0.13O2 cathodes exhibit well-ordered layered structures consisting of hexagonal LiMO2 and monoclinic Li2MnO3 with smooth surfaces and well-crystallized particles (100-500 nm). LMNCO-7.0 exhibits smaller particle sizes than LMNCO-5.5 and LMNCO-8.5 and better electrochemical performance. The first discharge capacity and Coulombic efficiency of LMNCO-7.0 are 232.31 mAh g(-1) and 73.2%, respectively. After 50 cycles, discharge capacity of LMNCO-7.0 decrease to 194.93 mAh g(-1). LMNCO-7.0 cathode shows superior discharge capacity and rate performance due to its low charge transfer impedance and small average quasi spherical particle diameter.