Layered transition metal oxides are promising cathode materials for sodium‐ion batteries applicable for low‐cost energy storage systems. However, their cycle stability needs to be substantially improved to meet the requirements of practical applications. Specifically, the issues related to electrolyte stability and the formation of an unstable cathode–electrolyte interface (CEI) remain unsolved. Herein, it is shown that an electrolyte with high fluorine content may induce a robust fluorinated CEI on Na_2/3Ni_1/3Mn_2/3O₂ cathode, a representative transitional metal oxide, which can efficiently passivate its surface and suppress continuous electrolyte decomposition during cycling. As a result, the cells deliver a remarkably improved rate capability and cycle stability. Density functional simulations further validate the superior stability of fluorinated electrolyte on cathodes with low highest occupied molecule orbital energy and high dissociation energy barriers. This finding demonstrates the favorable role of fluorinated electrolytes for improving the long‐term cycle stability of Na_2/3Ni_1/3Mn_2/3O₂ cathode toward grid‐scale applications.

中文翻译：

---

具有优异氧化稳定性的氟化碳酸盐电解质可确保钠离子电池中Na2 / 3Ni1 / 3Mn2 / 3O2阴极的长期循环稳定性

层状过渡金属氧化物是适用于低成本储能系统的钠离子电池正极材料。但是，它们的循环稳定性需要大大提高以满足实际应用的要求。特别是，与电解质稳定性和不稳定的阴极-电解质界面（CEI）形成有关的问题仍未解决。在此，表明具有高氟含量的电解质可以在Na _2/3 Ni _1/3 Mn _2/3 O ₂上诱导强健的氟化CEI。阴极，一种代表性的过渡金属氧化物，可以有效地钝化其表面并抑制循环过程中电解质的连续分解。结果，电池提供了显着改善的速率能力和循环稳定性。密度泛函仿真进一步验证了氟化电解质在阴极上具有较低的最高占据分子轨道能和较高的离解能垒的优异稳定性。这一发现证明了氟化电解质在改善Na _2/3 Ni _1/3 Mn _2/3 O ₂阴极在电网规模应用中的长期循环稳定性方面的有利作用。