Layered Li-rich oxides (LLROs) attract much attention due to their high capacities. However, the electrolyte decomposition and interfacial reactions especially driven by the catalysis effect of high-valance transition metal ions under high voltage cause severe performance recession, hindering their practical applications. Lithium fluoride (LiF) is an effective component in both cathode electrolyte interphase (CEI) and solid electrolyte interphase (SEI) films. In this work, lithium 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonimide (LiHFDF) is employed as a novel electrolyte additive for generating LiF-abundant interphase on LLRO. With the addition of LiHFDF, the capacity retention and Coulombic efficiency of the LLRO are improved noticeably. In addition, the interfacial side reactions and voltage decay issues are mitigated. Transmission electron microscopy and X-ray photoelectron spectroscopy measurements confirm that a compact and thin CEI film with more LiF is formed on the cathode surface for the cell using LiHFDF, which is beneficial for the enhancement of the electrochemical performance. Moreover, differential scanning calorimetry (DSC) investigations reveal that the LLRO electrode with LiHFDF has improved safety compared to that with the blank electrolyte. This work provides an effective LiF-generating electrolyte additive for high-voltage LLROs, which is believed to be positive for other high-voltage cathode materials.

层状富锂氧化物（LLRO）因其高容量而备受关注。然而，特别是由高价过渡金属离子在高压下的催化作用驱动的电解质分解和界面反应会导致严重的性能衰退，阻碍了它们的实际应用。氟化锂 (LiF) 是正极电解质中间相 (CEI) 和固体电解质中间相 (SEI) 膜中的有效成分。在这项工作中，锂 1,1,2,2,3,3-六氟丙烷-1,3-二磺酰亚胺（LiHFDF）被用作一种新型电解质添加剂，用于在 LLRO 上生成富含 LiF 的界面。随着 LiHFDF 的加入，容量保持率和库仑LLRO 的效率显着提高。此外，减少了界面副反应和电压衰减问题。透射电子显微镜和 X 射线光电子能谱测量证实，使用 LiHFDF 的电池在阴极表面形成了具有更多 LiF 的致密薄 CEI 膜，这有利于提高电化学性能。此外，差示扫描量热法 (DSC) 研究表明，与空白电解质相比，具有 LiHFDF 的 LLRO 电极具有更高的安全性。这项工作为高压 LLRO 提供了一种有效的产生 LiF 的电解质添加剂，据信这对其他高压正极材料是积极的。