Radially Oriented Single-Crystal Primary Nanosheets Enable Ultrahigh Rate and Cycling Properties of LiNi _0.8 Co _0.1 Mn _0.1 O ₂ Cathode Material for Lithium-Ion Batteries

Ni-rich Li[Ni _x Co _y Mn _{1− x − y} ]O ₂ (x ≥ 0.8) layered oxides are the most promising cathode materials for lithium-ion batteries due to their high reversible capacity of over 200 mAh g ⁻¹ . Unfortunately, the anisotropic properties associated with the α-NaFeO ₂ structured crystal grains result in poor rate capability and insufficient cycle life. To address these issues, a micrometer-sized Ni-rich LiNi _0.8 Co _0.1 Mn _0.1 O ₂ secondary cathode material consisting of radially aligned single-crystal primary particles is proposed and synthesized. Concomitant with this unique crystallographic texture, all the exposed surfaces are active {010} facets, and 3D Li ⁺ ion diffusion channels penetrate straightforwardly from surface to center, remarkably improving the Li ⁺ diffusion coefficient. Moreover, coordinated charge–discharge volume change upon cycling is achieved by the consistent crystal orientation, significantly alleviating the volume-change-induced intergrain stress. Accordingly, this material delivers superior reversible capacity (203.4 mAh g ⁻¹ at 3.0–4.3 V) and rate capability (152.7 mAh g ⁻¹ at a current density of 1000 mA g ⁻¹ ). Further, this structure demonstrates excellent cycling stability without any degradation after 300 cycles. The anisotropic morphology modulation provides a simple, efficient, and scalable way to boost the performance and applicability of Ni-rich layered oxide cathode materials.