Plasma-Induced CoF₂ Formation and Carbon Coating for Bond Adjustment and Polarization Inhibition in High-Rate Li/CF_x...

Fluorinated carbon (CF_x) contains strong covalent C-F bonds, leading to severe electrochemical polarization in Li/CF_x batteries with a limited rate performance. Herein, a synergy technology was developed to prepare a CF_x/CoF₂/C composite for a high-rate Li/CF_x battery combining bond adjustment and polarization inhibition effects. Typically, the CF_x/CoF₂/C composite in situ generated coupling with a mixed-liquid phase reaction and C₂H₂/Ar plasma-inducing technology. In detail, the intermediate/CF_x mixtures were prepared by mixing Co(NO₃)₂ as a cobalt source and NaOH as a precipitant, immediately following the C₂H₂/Ar plasma treatment. The introduction of CoF₂ favors the C₂H₂ decomposition into the carbon layer deposition during the plasma bombardment. Furthermore, the as-designed composite possesses rich semi-ionic C-F bonds, which suppress the polarization of CF_x. The charge transfer resistance of the CF_x/CoF₂/C composite is reduced from 267.9 to 51.7 Ω compared with raw CF_x. The energy density of the CF_x/CoF₂/C cathode increased to 1.89 times with a value as high as 1185.65 Wh/kg at 15 C. This novel cathode combines energetic CoF₂ and a conductive carbon layer to modify CF_x by plasma-inducing technology, synergistically achieving CF_x bond adjustment and polarization inhibition to address high-rate batteries.