Fluorinated Nanographite as a Cathode Material for Lithium Primary Batteries

Lithium/fluorinated carbon (Li/CFx) batteries face the problems of low rate performance and initial voltage delay. Herein, we propose a novel type of fluorinated nanographite as a cathode material for Li/CFx batteries through the direct fluorination of nanographite. The structure of fluorinated nanographite, including crystalline phase, particle size, fluorine content, and the properties of C-F bonding, strongly depend on the fluorination temperature. The fluorinated nanographite prepared at 450 degrees C (FG-450) shows the highest specific capacity, 837.4 mAhg(-1) at 10 mAg(-1), along with a discharge plateau of 2.54 V, responding to an energy density of 2004.5 Whkg(-1). The highlights of the fluorinated nanographite are to deliver high rate performance and overcome the initial voltage delay. FG-450 can be discharged at a high rate of about 3.6 C, delivering a high power density of 5460 Wkg(-1) with a remaining energy density of 1030.5 Whkg(-1). The good electrochemical performance of the FG-450 sample is ascribed to the combined effect of its nanoparticle size, large specific surface area, and continuous stacking porosity.