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.

Focusing on the failure mechanism of active materials during charging–discharging, the mechanical properties of Li–Sn alloys are studied by density functional theory, including elastic moduli, Poisson's ratio, anisotropy, and brittleness-ductility.

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Sodium and potassium are considered to be the most promising anode candidates due to their easy availability, low‐cost and similar chemical properties to lithium. Here, novel 3D accordion‐like fluorinated graphite nanosheets (FGNSs) are reported as cathodes for sodium primary batteries (SPBs) and potassium primary batteries (PPBs). The FGNSs‐x cathode exhibits unprecedented power and energy density due to the impressive 3D structure, high F/C ratio (1.0), and more surface CC bonds (7.14%). The FGNSs‐1.0 exhibits very high specific capacities of 831.3 and 834.1 mAh g−1 for SPBs and PPBs, respectively, close to the theoretical capacity. Besides, the maximum energy density of FGNSs‐1.0 in SPBs and PPBs are 1960.5 and 2144.6 Wh kg−1, respectively. The maximum power density for Na/CFx and K/CFx batteries could reach up to 7076.8 and 6227.4 W kg−1, respectively. The electrochemical performance of FGNSs‐1.0 at extreme temperatures (−30 to 100 °C), long storage time (60 days), high mass loading (3.6 mg cm−2), and pouch‐type cell is also evaluated for the first time. Surprisingly, FGNSs‐1.0 has outstanding performance in these projects. Therefore, the new‐type Na/CFx and K/CFx primary battery systems developed here have broad application prospects in high‐energy applications that require high‐power, low‐cost, and normal use under extreme conditions.

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