Fluorinated MWCNTs for Preparation of High-Stability Li–SnO2 Batteries

The electrochemical performance of fluorinated multiwalled carbon nanotubes (F-MWCNTs) as a new type of conductive agent for Li–SnO 2 batteries has been studied. Multiwalled carbon nanotubes (MWCNTs) were fluorinated to obtain F-MWCNTs with core–shell structure (fluorocarbon atomic ratio C/F = 1:1). The unique tubular structure of the F-MWCNTs allows more Li + ions and electrons to enter the channel around the active material CF 1 , which increases the electrochemical reaction effect and reduces the polarization effect of the batteries, thereby improving the utilization of the active material, and the capacity as well as the stability of the discharge plateau of the resulting batteries. The F-MWCNTs are an excellent alternative to the traditional conductive graphite. The SnO 2 @F-MWCNTs battery showed high specific capacity (1588.71 mAh g −1 at 100 mA g −1 ), excellent cycle performance (962.92 mAh g −1 after 100 cycles), excellent coulombic efficiency (99.89%), and low internal resistance in repeated electrochemical tests.