Conductive Carbon-Wrapped Fluorinated Hard Carbon Composite as High-Performance Cathode for Primary Lithium Batteries

Abstract

Lithium/carbon fluoride (Li/CFx) batteries have been widely researched due to their high theoretical specific energy. To create a high-performance electrode, the fluorinated hard carbon (FHC) is prepared by direct gas-phase fluorination. It has a high F/C ratio of 0.95 based on the gravimetric method. Selecting hard carbon (HC) with a high surface area as the carbon source allows for FHC to achieve suitable interlayer spacing and specific surface area, as well as abundant pore structures to facilitate rapid lithium ion transportation. Additionally, a composite of graphene and carbon nanotubes (CNTs) is coated on the surface of FHC, enhancing electron transport speed. The resulting FHC&C exhibits a very high energy density of 1256 Wh kg−1 and an excellent power density of 72,929 W kg−1 at a high rate of 40 C. Moreover, compared to commercial CFx, FHC&C exhibits higher energy and power densities, thus presenting a promising practical application prospect.

High Energy Density of Ball-Milled Fluorinated Carbon Nanofibers as Cathode in Primary Lithium Batteries

“…Other sub-fluorinated nanocarbons would be considered to extend the proposed concept of dual sub-fluorination, e.g., graphitized carbon blacks or nanodiscs. Although the energy and power densities do not exceed the best current performances, e.g., 92.5 kW/kg in [ 7 ], 72.9 kW/Kg in [ 10 ], and 24.364 kW/kg in [ 23 ], the comparison under strictly similar electrochemical operating conditions between the initial fluorinated material and the milled one highlights benefits. This method could be used for a variety of materials [ 8 , 15 ].…”

“…Because fluorinated carbons (CFxs) exhibit the highest theoretical energy density among current cathode materials for lithium primary batteries, extensive efforts are devoted to the enhancement of either their energy density, their power density, or both (see recent review papers [ 1 , 2 , 3 , 4 ]). The very recent strategies involve (i) considering new carbonaceous precursors for fluorination or innovative fluorination routes [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ], (ii) chemical changes in the CFx, either on the surface or in the bulk [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], and (iii) change in the electrolyte composition [ 13 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Ball milling, a simple process for reducing the particle size of a compound, is widely used for electrode materials [ 30 , 31 , 32 , 33 , 34 ], creating more space to accumulate the LiF(s) particles formed.…”

Synthesis of Ni-Cu-CNF Composite Materials via Carbon Erosion of Ni-Cu Bulk Alloys Prepared by Mechanochemical Alloying

“…[5][6][7][8][9]. Therefore, the attractiveness of CNM-based composites is also at a high level [10][11][12][13][14][15][16][17][18].…”