La3+掺杂对LiNi0.8Co0.15Al0.05O2结构和电化学性能的影响

采用共沉淀法制备添加了La3+的LiNi_0.8Co_0.15Al_0.05O₂正极材料, 通过XPS、X射线分析仪、扫描电镜、电化学工作站、电池充放电测试系统详细地探讨了不同添加量的La3+对材料的结构、形貌和电化学性能的影响。结果显示, 与无添加的LiNi_0.8Co_0.15Al_0.05O₂正极材料比较, 添加了La3+的材料一次颗粒尺寸更大, 球形度更好且材料的电极R_sf+R_ct阻抗均显示有所降低; 当添加x=0.01时, 材料的大电流循环稳定性得到了较大提升, 1 C条件下经过100次循环后, 添加La3+材料容量保持率为75.81 %, 而未添加材料容量保持率只有49.57 %; 添加了La3+材料制得的电池在0.5、1、5 C倍率下的放电比容量也要明显高于无添加材料。 

Effect of La3+ doping on the structure and electrochemical properties of LiNi0.8Co0.15Al0.05O2

Co-precipitation method was used to prepare LiNi_0.8Co_0.15Al_0.05O₂ anode materials with La3+ added. The XPS, X-ray analyzer, scanning electron microscope, electrochemical workstation, and battery charge and discharge test system were used to discuss the effects of different addition of La3+ on the structure, morphology and electrochemical performance of anode materials. Results show that, compared with the non-added LiNi_0.8Co_0.15Al_0.05O₂ cathode material, the material with La3+ has a larger primary particle size, better sphericity, and the Rsfand Rct impedance of the martials shows a decrease. When the doping amount of La3+ is x=0.01, the material's high-current cycle stability is greatly improved. After 100 cycles under 1 C, the capacity retention of La3+ is 75.81%, while that of the non-added materials is only 49.57%. Apart from that, the discharge specific capacity of the battery adding La3+ material at 0.5 C, 1 C, or 5 C is also significantly higher than that of non-added materials