Sandwich-Model Cathode Electrolyte Interphase Facilitating All-Climate High-Voltage Nickel-Rich Cathode-Based Lithium...

All-climate lithium metal batteries are highly needed, but remains a huge challenge in cycling life due to the existence of unstable electrode electrolyte interphases, especially with nickel-rich layered oxide cathode at high cut-off voltage. To address this question, a functional and robust sandwich-model cathode electrolyte interphase (CEI) is proposed, derived from a LiBF₄-based electrolyte modified with para-fluorobenzeneacetonitrile (P-FBCN) additive, to realize the stability of 4.8 V Li||LiNi_0.94Co_0.05Mn_0.01O₂ (NCM94) battery operated from -60 to 60 °C. The LiF-rich sandwich-model CEI features an outer layer of LiB_xO_y-rich to enhance mechanical/thermal stability, and the inner -C≡N-rich anchoring layer to facilitate Li⁺ conduction and inhibit the dissolution of transition metal ions. Notably, the 7.6 Ah-grade Li||NCM94 pouch cell with such electrolyte can yield a high energy density of 544 Wh kg^-1 with a long lifespan of 158 cycles.