NCM811 precursor with concentration gradients is prepared by adjusting the feeding method of MnSO₄·H₂O in the co-precipitation method. X-ray diffraction patterns show that the precursors have good crystal structure of β-Ni(OH)₂. Energy dispersive X-ray spectroscopy shows that the precursor sample performs relatively gentle concentration gradient distributions and scanning electron microscope presents that the precursor delivers a good sphericity and concentrated particle size distribution. The prepared NCM811 material also has good crystal structure and gentle concentration gradient distributions. Electrochemical tests show that it exhibits a better cycle performance of 98.0% capacity retention after 200 cycles at the current density of 1C, which is obviously better than the intrinsic material (87.5%). X-ray diffraction patterns presents unchanged crystal structure and transmission electron microscopy presents clear lattice fringes after 200 cycles. In contrast, part of crystal structure of the intrinsic material transforms into NiO₂ phase and Ni in Li layer occupying is very serious after 200th cycles and its lattice fringes are distorted with irregular direction. All of these results exhibit that the side reactions between nickel ions and the electrolyte can be effectively suppressed through the design of gradient structure, so it can improve the structural stability and cycle stability.

通过调整共沉淀法中MnSO ₄ ·H ₂ O的进料方式，可以制备出具有浓度梯度的NCM811前驱体。X射线衍射图谱表明前驱体具有良好的β-Ni（OH）₂晶体结构。。能量色散X射线光谱法表明前体样品表现出相对缓和的浓度梯度分布，而扫描电子显微镜表明前体样品具有良好的球形度和集中的粒径分布。制备的NCM811材料还具有良好的晶体结构和缓和的浓度梯度分布。电化学测试表明，在1C的电流密度下200次循环后，它表现出更好的循环性能，容量保持率为98.0％，这明显好于固有材料（87.5％）。X射线衍射图样显示未改变的晶体结构，透射电子显微镜显示200个循环后出现清晰的晶格条纹。相反，本征材料的部分晶体结构转变为NiO ₂在第200次循环后，Li相中的Ni相和Ni占据非常严重，其晶格条纹向不规则方向变形。所有这些结果表明，通过梯度结构的设计可以有效地抑制镍离子与电解质之间的副反应，因此可以提高结构稳定性和循环稳定性。