Fluorinated reed-carbon with three-dimensional porous channels to boost high-rate performance of lithium/fluorinated carbon battery

The high-rate performance of lithium/fluorinated carbon (Li/CF_x) battery remains a challenge due to poor discharge dynamics behavior accompanied by the overheating issue. We developed a novel fluorinated reed-carbon with three-dimensional (3D) porous channels to favor discharge dynamics behavior achieving excellent discharge performance as high as 5 C. Typically, the preparation of fluorinated reed-carbon mainly involves three steps, namely, crushing into powders, pre-carbonization of reed and precise fluorination. During the fluorination process, we precisely controlled the fluorination temperature in range of 330–370 °C and gas ratio (F₂ of ~ 15 vol%) to optimize the fluorine carbon ratio. This kind of CF_x possesses the novel structure at the scale of micron level ranging from 0.5 to 3 μm, which favors the electrolyte and charge transport through the channels smoothly. This 3D porous structure increases the specific surface area of the CF_x material, providing more chemical reaction sites to enhance discharge dynamics behavior and effectively hinder the volume expansion of batteries, which is conductive to improve the high-rate performance of Li/CF_x battery. This low-cost and facile approach opens up a novel pathway to design carbon materials and CF_x for Li/CF_x battery.