Research On Preparation And Application In The Lithium Batteries Of Fluorinated Carbon Materials

In this paper, fluorinated graphite (F-Graphite) was chose as the active material of lithium batteries'cathode material. Coin-type lithium batteries were prepared and their discharge performance were tested, which exhibited high specific capacity (800 mAh/g), high specific energy (1883 mWh/g) and high working voltage (2.65 V) at 0.1 mA cm-2 current density. However, the discharge performance of F-Graphite lithium batteries went down remarkably at 1C rate.Meanwhile, different methods to improve the discharge performance of F-Graphite lithium batteries were carried out. The multi-walled carbon nanotubes (MWCNTs) were chose as conductive agent, which could improve rate performance of lithium batteries remarkably. The metal, metal oxide, conductive polymer was doped into F-Graphite, which also could change the discharge performance of lithium batteries to some extent. The proposal of operating guide of electrolyte was pointed out by testing the discharge performance of lithium batteries, which exhibited high specific capacity and working voltage at the temperature range of 20℃~60℃.The fluorinated multi-walled carbon nanotubes (F-MWCNT) using high temperature gas methods were prepared. The discharge performance of F-MWCNT lithium batteries were tested, showing the larger specific capacity and higher working voltage than those of the F-Graphite lithium batteries.Finally, the mechanism of markedly improved discharge performance of lithium batteries by using MWCNTs as conductive agent was analyzed theoretically. The innner intercalation between F/C ratio and construction destroy degree of MWCNT was put forward. The diffusion coefficient of lithium-ion in the F-Graphite and F-MWCNT electrode materials was calculated.