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

Abstract

Fluorinated 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 77456W kg-1 and an energy density of 1067Wh 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 881W 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.