Analysis of the Irreversible Capacity Loss on Carbons for Li-Ion Batteries 1999-01-2464
Various techniques are used to characterize the physico-chemical properties of carbon materials (e.g., transmission electron microscopy, x-ray diffraction, and Raman spectroscopy) for Li-ion batteries. A convenient method to observe the chemical reactivity of carbons is to monitor their oxidation behavior by measuring the weight loss as carbon reacts with oxygen to form gaseous species such as CO and CO2. The results obtained by thermal analysis (TGA and DTA) of three types of cokes: (i) fluid coke, (ii) coal-tar pitch delayed coke and (iii) needle coke are presented. The aim of this paper is to utilize thermal analysis to investigate the active sites on petroleum and pitch cokes and to examine their affect on the irreversible capacity loss. Data from this study and the published literature are used in the analysis of the relationship between the physical properties of carbon and the irreversible capacity loss during the initial cycle.