Although single-crystalline LiNi_xCo_yMn_1-x-yO₂ (SC NCM) materials have been confirmed to have advantages in cycle performance, storage performance and thermal stability, the comprehensive performance of SC NCM materials is not perfect enough nowadays. And the current research on the modification mostly focuses on polycrystalline NCM materials, the modification of SC NCM materials is rare. Therefore, the synthesis and modification of SC NCM materials deserve special attention. In this work, the SC high-nickel LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) is modified by doping with titanium (Ti) element. The doped material can maintain better structural stability, and suppress the side reaction between the material interface and the electrolyte, so the cycling performance is significantly improved. Doping enlarges the transport channel of Li⁺ in the material, thereby increasing the rate property. The lattice slip phenomenon of the modified material under high voltage is significantly suppressed, and the oxygen release and the reactivity with the electrolyte at high temperature of the material after delithiation are reduced, so the high voltage resistance and thermal stability are significantly enhanced. In conclusion, the comprehensive properties of SC NCM811 materials are improved by doping, and detailed mechanism study is carried out, which can provide reference for the further modification of SC NCM materials.

虽然单晶LiNi _x Co _y Mn _1-xy O ₂ (SC NCM)材料已被证实在循环性能、储存性能和热稳定性方面具有优势，但目前SC NCM材料的综合性能还不够完善。而目前对改性的研究主要集中在多晶NCM材料上，SCNCM材料的改性很少见。因此，SC NCM材料的合成和改性值得特别关注。在这项工作中，SC高镍LiNi _0.8 Co _0.1 Mn _0.1 O ₂(NCM811) 通过掺杂钛 (Ti) 元素进行改性。掺杂后的材料可以保持较好的结构稳定性，抑制材料界面与电解液的副反应，从而显着提高循环性能。掺杂扩大了 Li ^{+的传输通道}在材料中，从而增加速率特性。改性材料在高压下的晶格滑移现象得到显着抑制，脱锂后材料在高温下的氧释放和与电解液的反应性降低，因此耐高压和热稳定性显着增强。综上所述，通过掺杂提高了SC NCM811材料的综合性能，并进行了详细的机理研究，可为SC NCM材料的进一步改性提供参考。