O3-type layered transition metal (TM) oxides are widely used as cathode materials for Na-ion batteries due to their high energy density potential, enabled by the state of charge (SoC)-dependent transition from octahedral (O-type) to prismatic (P-type) structures during Na-ion (de)sodiation. However, the O–P transition is often criticized for compromising the Na-ion mobility and limiting the cycle life. Herein, we reveal the intrinsic correlation between O–P transitions, oxygen behaviors, and Na-ion kinetics. We demonstrate that a compositionally versatile, entropy-tailored approach can promote preferred transitions (characterized by large lattice parameter deviations in the O-type region and rapid O–P biphasic reactions), enhancing Na-ion migration, as revealed by in situ high-energy synchrotron X-ray diffraction (HEXRD). Additionally, irreversible oxygen loss at high SoC is effectively mitigated, while TM migration and surface reconstruction are greatly suppressed, further accelerating Na-ion transport and stabilizing the structure, as confirmed by X-ray absorption spectroscopy (XAS) and theoretical analyses. The result is an exceptionally high rate capability of 88.7 mAh g^–1 at 20 C (2.4 A g^–1) with a superior normalized retention of 72.6%, accompanied by a prolonged lifetime with 74.3% retention after 1000 cycles. This work advances the understanding of the chemistry–property relationships in O3-type layered cathodes and broadens the prospects for fabricating high-power-density electrodes.

中文翻译：

---

熵定制快速充电钠层阴极


O3 型层状过渡金属 （TM） 氧化物因其高能量密度潜力而被广泛用作钠离子电池的正极材料，这是通过在钠离子（脱）钠化过程中从八面体（O 型）向棱柱形（P 型）结构的荷电状态 （SoC） 依赖性转变实现的。然而，O-P 转变经常因损害 Na 离子淌度和限制循环寿命而受到批评。在本文中，我们揭示了 O-P 转变、氧行为和 Na 离子动力学之间的内在相关性。我们证明，成分通用、熵定制方法可以促进择优跃迁（以 O 型区域的大晶格参数偏差和快速的 O-P 双相反应为特征），增强 Na 离子迁移，如原位高能同步加速器 X 射线衍射 （HEXRD） 所揭示的那样。此外，正如 X 射线吸收光谱 （XAS） 和理论分析所证实的那样，高 SoC 下的不可逆氧损失得到了有效缓解，同时 TM 迁移和表面重建得到极大抑制，进一步加速了 Na 离子传输并稳定了结构。结果是在 20 C 时 88.7 mAh g^–1 （2.4 A g^–1） 的超高倍率能力，72.6% 的优异归一化保留率，同时在 1000 次循环后使用寿命延长至 74.3%。这项工作促进了对 O3 型层状阴极中化学-性能关系的理解，并拓宽了制造高功率密度电极的前景。