Carbon‐Source‐Regulated Microstructural Evolution and Sodium Storage Behavior of Carbon Fluoride Cathodes

Sodium/fluorinated carbon (Na/CF _x ) primary batteries are attractive for their high theoretical energy density, yet their practical application is constrained by sluggish Na ⁺ transport kinetics. Herein, fluorinated graphite (MF015) and fluorinated soft carbon (MF017) are selected as representative cathode materials to systematically investigate the effects of carbon precursor microstructure and CF bonding configurations on electrochemical performance. MF017 exhibits a higher specific surface area (294.57 m ² ·g ⁻¹ ) and larger pore volume (0.18 cm ³ ·g ⁻¹ ) than MF015, facilitating enhanced ion transport. X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analyses reveal that MF015 is dominated by covalent CF bonds, whereas MF017 contains a higher proportion of semi‐ionic CF bonds, which improve interfacial reaction activity. As a result, MF017 delivers a superior discharge capacity of 913.1 mAh·g ⁻¹ at 100 mA·g ⁻¹ , compared to 704.7 mAh·g ⁻¹ for MF015, and maintains stable performance at high current densities of 500 and 1000 mA·g ⁻¹ . Also, Galvanostatic intermittent titration technique (GITT) measurements confirm that MF017 exhibits faster Na ⁺ diffusion kinetics. This work elucidates the critical role of microstructure and CF bonding in regulating Na/CF _x reaction kinetics and provides guidance for the rational design of high‐performance fluorinated carbon cathodes.