Lithium/fluorinated carbon (Li/CF x ) primary batteries have essential applications in consumer electronics and medical and high-power military devices. However, their application is limited due to the difficulty in achieving simultaneous high power density and high energy density in the CF x cathode. The tradeoff between conductivity and fluorine content is the decisive factor. Herein, by rational design, 3D porous fluorinated graphene microspheres (FGS-x) with both high conductivity and a high F/ C ratio are successfully synthesized for the first time. FGS-x possesses an F/C ratio as high as 1.03, a nanosheet structure with hierarchical pores, abundant CC bonds, few inactive C−F 2 bonds, and electrochemically active C−F bonds. The beneficial features that can increase discharge capacity, shorten the diffusion length for both ions and electrons, enhance the Li + intercalation kinetics, and accommodate the volume change are demonstrated. The Li/FGS-1.03 coin cell delivers an unprecedented power density of 71,180.9 W/kg at an ultrahigh rate of 50 C (43.25 A/g), coupled with a high energy density of 830.7 Wh/kg. Remarkably, the Li/FGS-1.03 pouch cell exhibits a record cell-level power density of 12,451.2 W/kg at 20 C. The in-depth investigation by the ex situ method on structural evolution at different discharge depths reveals that the excellent performance benefits from the structural stability and the uniform formation of LiF. The FGS-1.03 cathode also has excellent performance in extreme operating temperatures (0 to 100 °C) and high active material mass loading (4.3 mg/cm 2 ). These results indicate that the engineered fluorinated graphene developed here has great potential in applications requiring both high power density and high energy density.

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Reasonable design of matrix with strong adsorption for polysulfides, fast reaction kinetics and simple preparation process is an urgent need for lithium-sulfur battery (Li-S battery) applications. Therefore, in this...

The application of fluorinated carbon (CFx)-based lithium/sodium/potassium primary batteries (LPBs/SPBs/PPBs) with superior theoretical energy density in high-power devices remains limited due to the poor rate performance resulting from the low intrinsic conductivity of highly fluorinated CFx materials. Herein, novel nano-silver modified fluorinated carbon nanotubes (FCNTs@Ag-x) composites with high electrical conductivity were prepared without sacrificing the high fluorine content. The dual excellent performance achieved by the FCNTs@Ag-200 cathode is attributed to the three-dimensional conductive network synergistically constructed by the interlaced FCNTs and coated nano-Ag, together with electrochemically active C-F bonds co-regulated by Ag atoms and curvature, as well as abundant conductive semi-ionic C-F bonds and graphite-like sp2 C=C bonds, and few inactive C-F2 bonds. The FCNTs@Ag-200 cathode delivers very high energy densities of 2167, 1930, and 2150 Wh kg-1 for LPBs, SPBs, and PPBs, respectively, close to the theoretical energy density. The Li/FCNTs@Ag-200 battery exhibits an ultimate power density of up to 80501 W kg-1 at an ultrafast rate of 50 C and can withstand a pulse discharge of 150 C (~129.75 A g-1). Remarkably, unprecedented power densities of 36650 and 40672 W kg-1 are achieved at a record rate of 25 C using FCNTs@Ag-200 as the cathode for Na/CFx and K/CFx batteries, respectively, which is a significant improvement over the state-of-the-art. Therefore, the advanced CFx-based primary batteries developed here are promising in applications that simultaneously require fast discharge, high energy density, high power density, and long-term storage.