Fluorinated carbons ( CFX) are promising cathode materials for lithium primary batteries due to their high energy density, yet suffer from poor electronic conductivity. Manganese dioxide ( MnO2), on the other hand, offers superior rate capability, but limited capacity. Here, we design MnO2/ CFx hybrid cathodes by combining MnO2 with CFX materials synthesized at controlled fluorination levels (x = 0.4–1.0) to synergistically optimize both energy and power performance. Structural and spectroscopic analyses reveal that moderate fluorination (x = 0.6) induces a favorable balance of semi-ionic C–F and interfacial O–F bonds, enhancing electron delocalization and charge transfer at the MnO2/ CFX interface. In contrast, excessive fluorination (x ≥ 0.8) leads to the formation of electrochemically inert C–F2 and C–F3 species, suppressing redox kinetics. As a result, MnO2/ CFX-0.6 delivers a discharge capacity of 390 mAh g–1−1 at 0.05 C and retains 182 mAh g–1−1 at 4 C, outperforming both pristine MnO2 and other CFX variants. This work establishes interfacial fluorine bonding configuration, not just bulk F/C ratio, as a critical design parameter for high-performance hybrid cathodes.
Modifying the softening point (SP) of pitch is crucial owing to its substantial influence on pitch applicability. This study presents a novel fluorination technique for engineering the SP of mesophase pitch (MP). Low-concentration fluorine gas was used to modify the edge sites of the MP, allowing for either an increase or decrease in the SP by controlling the gas reactivity. The fluorination was conducted with 20 vol% F2 gas under reaction temperature of 25, 50, and 75 ℃ for 2 h in atmospheric pressure. A reduction in SP was achieved through edge alkylation, with a decrease of up to 14.1% observed after the fluorination. Conversely, an increase in SP resulted from edge dealkylation at higher reaction temperatures. As the modified MPs retained perfect anisotropy, this study offers an effective strategy for adjusting the SP to meet application needs without causing structural deterioration.