Dual C-F bonding in fluorinated exfoliated graphite

Accordion-like graphites prepared by exfoliation of a low temperature graphite fluoride were fluorinated using F-2 gas in order to be considered as solid lubricants and electrode materials in primary lithium battery. The present work focuses on the fluorination mechanism of such material. In accordance with their high specific surface area, the fluorination is efficient even at room temperature. Whatever the treatment conditions, the accordion-like texture is maintained. The higher the reaction temperature, the higher the atomic ratio F/C. The fluorinated exfoliated graphite exhibit unusual dual C-F bonding. Both weakened covalent and covalent C-F bonds coexist. Moreover, the C-F bond strength is enhanced as a function of the fluorination temperature. (C) 2014 Elsevier B.V. All rights reserved.