Dual-phase engineering of CFx electrode and interphase enables low-temperature Li||CFx batteries

Low-temperature Li||CF x batteries undergo performance degradation due to the insulating nature of CF x and sluggish Li + kinetics. Herein, we present a dual-modification strategy integrating porous positive electrode architecture design with customized electrode-electrolyte interphase engineering to overcome these limitations. Our approach features: (i) plasma-enhanced chemical vapor deposition-constructed mesoporous CF x with conformal carbon coating, and (ii) electrolyte-mediated in situ formation of a sulfur-rich inorganic interphase layer on CF x surface. The engineered porous framework establishes efficient Li + diffusion channels, while the electrolyte-derived interphase significantly enhances Li + transport and desolvation kinetics. Moreover, the carbon coating substantially improves electronic conductivity and suppresses LiF stacking. The optimized Li||CF x system delivers capacities of 428.4 mAh g −1 at −50 °C and 2 A g −1 , and 333.4 mAh g −1 at −70 °C and 0.1 A g −1 . Practical 5 Ah pouch cells deliver competitive specific energies of 470 and 332 Wh kg −1 at −50 and −70 °C under 0.01 A g −1 , respectively.