Ni-rich layered metal oxide of LiNi_0.6Co_0.2Mn_0.2O₂ (NCM) is a promising cathode material for the next-generation lithium-ion batteries. The fast capacity fading caused by interfacial instability, bulk structural degradation and side reactions on electrode/electrolyte interface during cycling hampers its larger scale commercial applications. In this work, a combined modification strategy was implemented by coating with Li₂TiO₃ on particle surface and doping with PO₄^3- polyanion in bulk of the NCM cathode material. The large tetrahedral PO₄^3- polyanions doped into lattice structure suppresses cationic mixing and structure degradation, while the Li₂TiO₃ coating layer protects the particle surface and restrains side reactions. The co-modification strengthens overall structure stability for an excellent cycling performance. Moreover, the thin layered Li₂TiO₃ coating material with three-dimensional channels for ion transport and the enlarged interlayer spacing by PO₄^3--doping enhance capacity and facilitate Li⁺ ions diffusing. These factors result in a superior rate capability. With the collaborative cooperation of Li₂TiO₃ coating and PO₄^3- doping, the sample with 1 mol% coating and 0.03 mol% doping content delivers a reversible specific capacity of 167.2 mAh g^-1 at 5 C and 157.8 mAh g^-1 at 10 C, remains a capacity of 147.7 mAh g^-1 at 1 C after a long term 800 cycles with a retention of 77.4% at a high cut-off voltage of 4.5 V.

LiNi _0.6 Co _0.2 Mn _0.2 O ₂（NCM）的富镍层状金属氧化物是用于下一代锂离子电池的有前途的正极材料。在循环过程中，由于界面的不稳定性，整体结构的退化以及电极/电解质界面上的副反应而导致的快速容量衰减会阻碍其大规模的商业应用。在这项工作中，通过在颗粒表面涂覆Li ₂ TiO ₃并在NCM阴极材料的主体中掺杂PO ₄ ^3-聚阴离子，实现了组合的改性策略。大型四面体PO ₄ ^3-掺杂到晶格结构中的聚阴离子可抑制阳离子混合和结构退化，而Li ₂ TiO ₃涂层可保护颗粒表面并抑制副反应。共改性增强了整体结构的稳定性，从而具有出色的循环性能。此外，具有用于离子传输的三维通道的薄层Li ₂ TiO ₃涂层材料以及通过PO ₄ ^3-掺杂而增加的层间间距提高了容量并促进了Li ⁺离子的扩散。这些因素导致了较高的速率能力。在Li ₂ TiO ₃涂层和PO ₄的协同合作下^3-掺杂，具有1 mol％涂层和0.03 mol％掺杂含量的样品在5 C时可逆比容量为167.2 mAh g ^-1，在10 C时可逆比容量为157.8 mAh g ^-1，仍为147.7 mAh g ^-1长期800个循环后在1 C下保持在7. C，在4.5 V的高截止电压下的保持率为77.4％。