Synthesis and characterization of fluorinated carbon nanotubes for lithium primary batteries with high power density

Abstract

The synthesis and characterization of fluorinated carbon nanotubes have been carried out under an inert gas containing fluorine. All of the samples have been characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance ((13)C and (19)F ss-NMR) and transmission electron microscopy (TEM) techniques. The comparison of the effects of various experimental parameters on the structure of fluorinated materials allows the disclosure of the fluorination mechanism. It is shown that fluorine was intercalated into the outer part of the carbon nanotubes initially where graphene layers were coaxial within a distance of 0.60 nm. In contrast, the inner part of the carbon nanotubes was not intercalated. The electrochemical performance such as discharge capacity as a cathode for a primary lithium battery has also been investigated. The samples with a F/C ratio of 0.75 exhibited the best performance, namely high energy and power densities. The highest specific energy density and specific power density were 1147 Wh kg(-1) and 8998 W kg(-1), respectively, at a current density of 4 A g(-1).

Microwave‐assisted ionic liquid‐based micelle extraction combined with trace‐fluorinated carbon nanotubes in dispersive micro‐solid‐phase extraction to determine three sesquiterpenes in roots of Curcuma wenyujin

“…As shown in Figure B, a strong peak at 1215.3 cm −1 can be observed in the FTIR spectra, which is ascribed to the stretching vibration of C‐F. These observations are in agreement with those of a previous study …”

“…The results shown in Figure A indicate that the extraction efficiency of [C 10 VIM]Br was the most optimal among the four ILs. The possible reason is that as the alkyl chain length of the ILs increased, the hydrophobicity enhanced, which was conducive to the extraction of hydrophobic target compounds . When the alkyl chain increased to a certain length, the integrated effect of stereo‐hindrance and hydrogen‐bond was more dominant compared with the effect of similarity‐intermiscibility theory .…”

Enhanced electrochemical activity of rechargeable carbon fluorides–sodium battery with catalysts

“…A broad peak at 14.7°in the pristine electrodes shown in Fig. 4(a) can be assigned to the (0 0 1) peak of F-MWCNTs [12]. When the electrode was firstly discharged to 1.5 V, the original broad peak of F-MWCNTs disappeared, two new diffraction peaks at 38.4°and 55.7°can be well indexed to (2 0 0) and (2 2 0) reflection of NaF (JCPDS 36-1445).…”

Electrophilic Fluorination of Graphitic Carbon for Enhancement in Electric Double‐Layer Capacitance

“…The literature is bound with numerous methods adopted for the fluorination of carbon materials such as direct fluorination using F 2 ; plasma treatment using SF 6 ; photochemical fluorination using cyclic transparent optical polymer (CYTOP), XeF 2 and C 4 F 8 ; hydrothermal, sonochemical, and electrochemical fluorination using fluorine‐containing salts and precursors such as HF, BrF 3 , NH 4 F, and NH 4 BF 4 ; and thermal exfoliation of fluorinated graphite . A brief literature survey on the methods of fluorination is given in Table S1, Supporting Information.…”