Nickel-rich layered oxides are attractive cathode for lithium-ion batteries (LIBs) because of the high energy density and low cost. The critical problem is capacity fading caused by the highly reactive metastable phases under voltages of higher than 4.15 V. Herein, we find that facile Ar/H₂ plasma treating could produce oxygen vacancies that will readily transform into homogeneous spinel layer (∼ 6 nm) on the LiNi_0.8Co_0.1Mn_0.1O₂ (NCM₈₁₁) surface after a few cycles of lithiation/delithiation procedure. Owing to the structural matching between spinel and layered structure, the diffusion of Li ions could remain fast upon cycling. Besides, the spinel layer is electrochemically inert, which guarantees surface stabilization and inhibits the detrimental phase transition from H2 to H3 at high voltages. Under the protection of the homogeneous spinel layer, the NCM₈₁₁ electrode shows superior capacity retention of 91.2% after 200 cycles at the current density of 100 mA·g⁻¹. This work proposes a novel strategy of surface reconstruction to stabilize nickel-rich layered oxide materials for LIBs.

由于高能量密度和低成本，富镍层状氧化物是锂离子电池 (LIB) 的有吸引力的阴极。关键问题是在高于 4.15 V 的电压下由高反应性亚稳相引起的容量衰减。在此，我们发现简单的 Ar/H ₂等离子体处理可以产生氧空位，这些空位很容易转变为均匀的尖晶石层（~ 6 nm）在 LiNi _0.8 Co _0.1 Mn _0.1 O ₂ (NCM ₈₁₁) 经过几次锂化/脱锂过程后的表面。由于尖晶石和层状结构之间的结构匹配，锂离子的扩散可以在循环过程中保持快速。此外，尖晶石层是电化学惰性的，可确保表面稳定并抑制高压下从 H2 到 H3 的有害相变。在均质尖晶石层的保护下，NCM _{811电极在 100 mA·g} ^-1的电流密度下循环 200 次后显示出 91.2% 的优异容量保持率。这项工作提出了一种新的表面重建策略，以稳定用于锂离子电池的富镍层状氧化物材料。