Surface Engineering of Fluorinated Graphene Nanosheets Enables Ultrafast Lithium/Sodium/Potassium Primary Batteries

Abstract

AbstractFluorinated carbon (CFx) is considered as a promising cathode material for lithium/sodium/potassium primary batteries with superior theoretical energy density. However, achieving high energy and power densities simultaneously remains a considerable challenge due to the strong covalency of the C–F bond in the highly fluorinated CFx. Herein, an efficient surface engineering strategy combining surface defluorination and nitrogen doping enables fluorinated graphene nanosheets (DFG‐N) to possess controllable conductive nanolayers and reasonably regulated C–F bonds. The DFG‐N delivers an unprecedented dual performance for lithium primary batteries with a power density of 77456 W kg−1 and an energy density of 1067 Wh kg−1 at an ultrafast rate of 50 C, which is the highest level reported to date. The DFG‐N also achieves a record power density of 15 256 and 17 881 W kg−1 at 10 C for sodium and potassium primary batteries, respectively. The characterization results and density functional theory calculations demonstrate that the excellent performance of DFG‐N is attributed to surface engineering strategies that remarkably improve electronic and ionic conductivity without sacrificing the high fluorine content. This work provides a compelling strategy for developing advanced ultrafast primary batteries that combine ultrahigh energy density and power density.