TY  - JOUR
AU  - Wang, Kai
AU  - Feng, Yiyu
AU  - Kong, Lingchen
AU  - Peng, Cong
AU  - Hu, Yuanhang
AU  - Li, Weiyu
AU  - Li, Yu
AU  - Feng, Wei
PY  - 2023
TI  - The Fluorination of Boron-Doped Graphene for CFx Cathode with Ultrahigh Energy Density
JO  - Energy & Environmental Materials
SN  - 2575-0348
VL  - 6
IS  - 4
AB  - The enhancement of the fluorination degree of carbon fluorides (CFx) compounds is the most effective method to improve the energy densities of Li/CFx batteries because the specific capacity of CFx is proportional to the molar ratio of F to C atoms (F/C). In this study, B-doped graphene (BG) is prepared by using boric acid as the doping source and then the prepared BG is utilized as the starting material for the preparation of CFx. The B-doping enhances the F/C ratio of CFx without hindering the electrochemical activity of the C–F bond. During the fluorination process, B-containing functional groups are removed from the graphene lattice. This facilitates the formation of a defect-rich graphene matrix, which not only enhances the F/C ratio due to abundant perfluorinated groups at the defective edges but also serves as the active site for extra Li+ storage. The prepared CFx exhibits the maximum specific capacity of 1204 mAh g−1, which is 39.2% higher than that of CFx obtained directly from graphene oxide (without B-doping). An unprecedented energy density of 2974 Wh kg−1 is achieved for the as-prepared CFx samples, which is significantly higher than the theoretically calculated energy density of commercially available fluorinated graphite (2180 Wh kg−1). Therefore, this study demonstrates a great potential of B-doping to realize the ultrahigh energy density of CFx cathodes for practical applications.
UR  - https://doi.org/10.1002/eem2.12437
DO  - 10.1002/eem2.12437