Nickel(Ni)-rich layered materials have attracted considerable interests as promising cathode materials for lithium ion batteries (LIBs) owing to their higher capacities and lower cost. Nevertheless, Mn-rich cathode materials usually suffer from poor cyclability caused by the unavoidable side-reactions between Ni⁴⁺ ions on the surface and electrolytes. The design of gradient concentration (GC) particles with Ni-rich inside and Mn-rich outside is proved to be an efficient way to address the issue. Herein, a series of LiNi_0.6Co_0.2Mn_0.2O₂ (LNCM622) materials with different GCs (the atomic ratio of Ni/Mn decreasing from the core to the outer layer) have been successfully synthesized via rationally designed co-precipitation process. Experimental results demonstrate that the GC of LNCM622 materials plays an important role in their microstructure and electrochemical properties. The as-prepared GC3.5 cathode material with optimal GC can provide a shorter pathway for lithium-ion diffusion and stabilize the near-surface region, and finally achieve excellent electrochemical performances, delivering a discharge capacity over 176 mAh·g⁻¹ at 0.2 C rate and exhibiting capacity retention up to 94% after 100 cycles at 1 C. The rationally-designed co-precipitation process for fabricating the Ni-rich layered cathode materials with gradient composition lays a solid foundation for the preparation of high-performance cathode materials for LIBs.

富镍（Ni）的层状材料由于其更高的容量和更低的成本而成为有前途的锂离子电池正极材料，引起了人们的广泛兴趣。然而，由于表面上的Ni ⁴⁺离子与电解质之间不可避免的副反应，富锰的阴极材料通常遭受不良的循环性。事实证明，设计内部富含Ni和外部富含Mn的梯度浓度（GC）颗粒是解决此问题的有效方法。在此，一系列LiNi _0.6 Co _0.2 Mn _0.2 O ₂通过合理设计的共沉淀过程成功地合成了具有不同GC（Ni / Mn原子比从核到外层降低）的（LNCM622）材料。实验结果表明，LNCM622材料的气相色谱在其微观结构和电化学性能方面起着重要作用。所制备的具有最佳GC的GC3.5阴极材料可为锂离子扩散提供更短的路径并稳定近表面区域，并最终实现出色的电化学性能，放电容量超过176 mAh·g ^-1 在0.2 C的速率下，在1 C进行100次循环后，显示出高达94％的容量保持率。合理设计的共沉淀工艺用于制备具有梯度成分的富镍层状正极材料，为高性能制备奠定了坚实的基础LIB的阴极材料。