Unlocking Stable Operation of All‐Climate 4.6 V High‐Rate LiCoO 2 Batteries by Potential‐Dependent Interphase Engineering

Abstract High‐voltage lithium cobalt oxide (LiCoO 2 ) cathodes promise enhanced energy density but suffer from severe interfacial degradation under the voltage exceeding 4.55 V and extreme conditions. Herein, the study demonstrates 2,2,3,3‐tetrafluoropropyl 4‐methylbenzenesulfonate (FPTS) as a dual‐functional electrolyte additive that enables stable 4.6 V high‐rate LiCoO 2 batteries operation across −20 to 55 °C via potential‐dependent interphase engineering. FPTS features a narrow highest occupied molecular orbital (HOMO)‐lowest unoccupied molecular orbital (LUMO) gap (5.87 eV) and low Li + binding energy (−14.57 kJ mol −1 ), driving preferential decomposition to form fluorine (F)/sulfur (S)‐rich cathode‐electrolyte interphase (CEI)/solid‐electrolyte interphase (SEI) layers with superior ionic conductivity and mechanical robustness, significantly suppressing structural phase transition and interfacial degradation. Consequently, FPTS enables a record capacity delivery of 165 mAh g −1 under 10 C, far surpassing state‐of‐the‐art 4.6 V‐charged Li / LiCoO 2 batteries. The LiCoO 2 ||graphite full cells achieve improved performance in a wide temperature range. The practicality is further showcased by 1.6 Ah‐class pouch cells with 91% capacity retention after 100 cycles under 4.6 V. This work provides a molecular‐level design paradigm for all‐climate high‐energy‐density batteries.