High energy density of primary lithium batteries working with sub-fluorinated few walled carbon nanotubes cathode

Abstract

International audienceFluorinated carbon nanotubes used as cathode material exhibit a capacity exceeding the theoretical value when used in primary lithium battery. The measured experimental capacity, the faradic yield and the energy density were increased, exceeding the expected theoretical values for sub-fluorinated few walled carbon nanotubes (FWCNTs).Although the molar carbon/fluorine ratio was only of 0.37 (i.e CF0.37), an experimental capacity of 900 mAh.g−1 was obtained which is higher than the theoretical value of 521 mAh.g−1. With the same material, an unprecedented energy density of 2565 Wh kg−1 was reached associated with a faradic yield of 172%. The materials were deeply characterized using TEM, Raman and solid state 13C and 19F NMR in order to explain the extra-capacity. Such high electrochemical values can be correlated to the reinforcement effect of the central tube(s), coupled with a low amount of structural defects

Fluorinated graphene nanoribbons from unzipped single-walled carbon nanotubes for ultrahigh energy density lithium-fluorinated carbon batteries

“…Ragone plots of the prepared CF x cathodes (Fig. 4f) , which was higher than most of the CF x reported in the literature [19][20][21][22]. The increase in the discharge current density leads to the decrease in the energy density of the CF x cathode due to the drop in the operational potential and specific capacity.…”

“…Recently, our group [19,20] substituted hard carbon derived from biomass for conventional graphite as the raw carbonaceous materials of CF x , and the corresponding pro-ducts delivered energy densities of approximately 2600 W h kg −1 , higher than the theoretical value of CF 1 , thanks to the enhanced electrochemical activity of the C-F bond caused by periodic structure destruction. In addition, Ahmad et al [21,22] also demonstrated the extra capacity of CF x , derived from carbon nanodiscs and few-walled carbon nanotubes, due to the further consumption of Li + by the carbon host after electrochemical de-fluorination. Therefore, potential remains for further enhancing the energy density of CF x by considering the huge gap between the operational potential and the thermoneutral potential at 4.57 V, alongside the maneuverbility of its stoichiometry [23].…”

A brief review for fluorinated carbon: synthesis, properties and applications

“…Note that the type of C-F bond and F/C ratio are closely related to the electrochemical properties of fluorinated carbon. Thus, recently, tremendous efforts have been made to achieve the theoretical capacity of fluorinated carbon in the respect of tuning the type of C-F bond and F/C ratio by designing the raw materials and fluorination conditions [89,90].…”

Fluorinated carbonaceous nanoparticles as active material in primary lithium battery

“…In addition to these methods, the electrochemical deposition process presents several advantages notably the synthesis of powders or thin films with controlled thickness, morphology, and composition of the deposited films by adjusting the operating conditions. Several reports have been devoted to the fluorination of single- [15] or multi-wall nanotubes (MWCNTs) [16][17][18][19] and amorphous nanocarbons [20]. By surface modification of CFx compounds, high-rate capabilities and new functionalization have been reached [21,22].…”