Comparative performances for primary lithium batteries of some covalent and semi-covalent graphite fluorides

Abstract

Different graphite fluorides were prepared by three different synthesis ways: fluorination at room temperature, at 600 °C, and refluorination at 400 and 530 °C of a fluorinated graphite prepared at room temperature. All the samples have been characterized by 19F MAS NMR and FT-IR spectroscopies. Their electrochemical performances as cathode materials in primary lithium batteries have been investigated at room temperature and at 60 °C and as a function of the current density. Ageing behavior has been also studied using some liquid electrolytes. Refluorinated sample at 400 °C exhibits the best performances because of both its good average discharge potential and its discharge capacity, i.e. 2.54 V and 848 Ah kg −1, respectively. For this sample, the best specific energy density and specific power density are 2149 Wh kg −1 and 902 W kg −1, respectively.