Although O3-type NaCrO₂ has various merits as a promising cathode material for Na-ion batteries, only ∼0.5 mol Na⁺ in O3-type NaCrO₂ can be used because of irreversible phase transition by Cr migration to the Na layers. Thus, it is important to increase the Na⁺ content that can be reversibly de/intercalated by O3-type NaCrO₂. Through combined studies using first-principles calculation and experiments, we demonstrate that the presence of Sb⁵⁺ in the NaCrO₂ structure can suppress Cr migration even after charging to 4.1 V (vs. Na⁺/Na) and enables an increase in the Na content that can be reversibly de/intercalated. During charge/discharge at C/20 (1C = 175 mA g⁻¹), O3-type Na_0.72Cr_0.86Sb_0.14O₂ delivers a specific capacity of ∼175 mAh g⁻¹ corresponding to ∼0.72 mol Na⁺ de/intercalation, representing highly enhanced electrochemical performance compared with that of O3-type NaCrO₂, which exhibits poor coulombic efficiency of only ∼37% under the same conditions.

尽管 O3 型 NaCrO ₂作为一种有前途的钠离子电池正极材料具有各种优点，但由于 Cr 迁移到 Na 层的不可逆相变，O3 型 NaCrO _{2中只有约 0.5 mol Na} ⁺可以使用。因此，重要的是增加可以被O3型NaCrO _{2可逆脱/插的Na} ⁺含量。通过第一性原理计算和实验相结合的研究，我们证明了在 NaCrO _{2结构中存在 Sb} ⁵⁺可以抑制 Cr 迁移，即使在充电到 4.1 V ( vs . Na ⁺/Na) 并且能够增加可以可逆地脱/插的 Na 含量。在 C/20 (1C = 175 mA g ^-1 ) 的充电/放电过程中，O3 型 Na _0.72 Cr _0.86 Sb _0.14 O ₂提供～175 mAh g ^-1的比容量，对应于～0.72 mol Na ⁺脱/插，与O3型NaCrO ₂相比，表现出高度增强的电化学性能，后者在相同条件下表现出较差的库仑效率，仅为~37％。