Ultraviolet-Induced Formation of Silver Nanoparticles Anchored by the Conductive-Viscous Polypyrene–Polydopamine Copolymer on CFx Surface for High-Power Li/CFx Battery

The high energy density lithium/carbon fluoride (Li/CFx) battery meets the challenge of limited high-rate discharge performance due to the low intrinsic conductivity of CFx. Herein, an inorganic/organic (Ag/PPy-PDA) synergistic conductivity strategy is developed to suppress CFx polarization, addressing the ultrahigh rate of CFx batteries for the high F content. Bioinspired by mussel surface chemistry, UV-mediated synthesis of Ag nanoparticles on CFx surfaces is achieved through a polypyrene–polydopamine (PPy-PDA) copolymer-assisted reduction of a silver ammonia solution. During UV irradiation, the copolymer serves a dual function: stabilizing C–F bonds against alkaline degradation in silver ammonia solutions and hindering the defluorination under UV exposure. Detailed mechanistic studies reveal synergistic adhesive growth and surface-protection effects, enabling the precise Ag nanoparticle assembly on CFx. The as-designed CFx@PPy-PDA@Ag composite possesses the advantage of a high F/C ratio, excellent inorganic/organic conductive path, and good wettability of the electrolyte. Therefore, the optimal Li/CFx battery (CFx@PPy-PDA@Ag-10%) achieved a high discharge rate of 15000 mA·g–1, delivering a high-power density of 22,404.37 W·kg–1. This inorganic/organic (Ag/PPy-PDA) synergistic conductivity strategy lights up the high-rate Li/CFx batteries with a high F/C ratio. A DFT calculation is conducted for CFx, and the result shows that the conductivity is significantly improved, and the interaction between C–F bonds was significantly weakened after the Ag NPs are deposited on the surface.