Preparation and performance of industrial carbons derived cathodes for lithium/ fluorinated carbon primary batteries

Abstract

Four kinds of fluorinated carbon cathodes were fabricated with the industrial carbon materials (activated carbon, spherical graphite, expanded graphite and industrial graphene) to realize the universal applications of lithium/fluorinated carbon primary battery. The morphology, crystalline structure, chemical structure and electrochemical performance were systematically studied by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Raman spectra (Raman), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectro scopy(XPS), N2 adsorption-desorption isotherms and electrochemical test, etc. It was found that the fluorinated industrial graphene shows the highest specific capacity (945.4 mAh·g-1) at the discharge current density of 20 mA·g-1, which may benefit from the monofluorocarbon structure, high specific area and stable carbon structure. The fluorinated active carbon has the highest initial discharge voltage due to the abundant semi-covalent C—F bond, but its discharge voltage declines rapidly caused by the unstable structure. Although the fluorinated spherical graphite and fluorinated expanded graphite have the similar structure with the fluorinated industrial graphene, their specific capacities are lower, due to the presence of the highly fluorinated carbon atoms (CF2 and CF3). However, at high discharge current density, the fluorinated spherical graphite and fluorinated expanded graphite possess the similar value with the fluorinated industrial graphene. Considering the cost, they may be more suitable for the high power applications.

Keywords

• lithium/fluorinated carbon primary battery
• graphene
• electrochemistry
• structure-activity relationship
• cathode