Jiang Shengbo, Huang Ping, Lu Jiachun, Liu Zhichao
Northwest Institute of Nuclear Technology P.O. Box 69-14 Xi'an 710024 P. R. China
RSC Adv. 2021 Jul 21;11(41):25461-25470. doi: 10.1039/d1ra03873g. eCollection 2021 Jul 19.
The inferior rate capacity of lithium/fluorinated carbon (Li/CF ) batteries limits their application in the field, requiring large discharge current and high power density. Herein, we report a novel type of fluorinated carbon with superior performance through gas-phase fluorination of ketjenblack. The investigation shows that the F/C ratio of the fluorinated ketjenblack (FKB) increases with the fluorination temperature, whereas the discharge voltage decreases due to the lowered content of semi-ionic C-F bonds. Accordingly, a suitable fluorination temperature of 520 °C was selected, under which the product exhibits the largest specific capacity of 924.6 mA h g with discharge potential exceeding 3.1 V ( Li/Li) and the highest energy density of 2544 W h kg with power density of 27 493 W kg. This energy density is higher than the theoretical energy density of commercial fluorinated graphite (2180 W h kg). In addition, the sample delivers good rate capability demonstrated by a specific capacity retention ratio of 79.5% even at a current density of 20C. Therefore, the FKB material may have very promising practical applications in lithium primary batteries.
锂/氟化碳（Li/CF ）电池较差的倍率性能限制了它们在该领域的应用，这需要大放电电流和高功率密度。在此，我们通过对科琴黑进行气相氟化报道了一种具有卓越性能的新型氟化碳。研究表明，氟化科琴黑（FKB）的F/C比随氟化温度升高而增加，而由于半离子C-F键含量降低，放电电压下降。因此，选择了520℃的合适氟化温度，在此温度下，产物表现出最大比容量924.6 mA h g，放电电位超过3.1 V（Li/Li），最高能量密度2544 W h kg，功率密度27493 W kg。该能量密度高于商用氟化石墨的理论能量密度（2180 W h kg）。此外，该样品表现出良好的倍率性能，即使在20C的电流密度下，比容量保持率仍为79.5%。因此，FKB材料在锂原电池中可能具有非常广阔的实际应用前景。
