Authors:N. Kallithrakas-Kontos, K. Zoumi, S. Nikolakaki, and P. Kritidis
Most of the Greek lignite power plants have been installed in the area of Ptolemais, and a major part of them during the period
1981–1990. Aerosol filters collected in the first and the last years of the decade have been analysed for trace elements as
well as for radioactivity (total beta) content. Analysis was performed by radioisotope excited X-ray fluorescence, and 17
elements were determined. A special interest is focused on lead concentrations, an element whose environmental concentrations
are regulated by the Greek law; the results for lead were validated by atomic absorption spectrometry. Trace element and radioactivity
levels were found significantly lower than the current limit. Enrichment factors and correlation among the analysed elements
were also estimated.
Authors:S. K. Aghara, S. Venkatraman, A. Manthiram, and E. Alvarez II
Lithium-ion batteries are widely used as a power source for portable electronic devices. Currently, only 50-70% of the theoretical capacity of the layered oxide cathode (positive electrode) materials could be reversibly used. The reason for this limitation is not fully understood in the literature. Recent structural and chemical characterizations of chemically delithiated (charged) cathodes suggest that loss of oxygen from the lattice may play a role in this regard. However, during the chemical delithiation process any proton inserted from the solvent could adversely affect the oxygen content analysis data. The challenge in addressing this issue is to detect and determine precisely the proton content in the chemically delithiated samples. The prompt gamma-ray activation analysis (PGAA) facility at the Nuclear Engineering Teaching Laboratory (NETL) is used to determine the proton content in the layered oxide cathode LiNi0.5Mn0.5O2 before and after chemical delithiation. The data are compared with those obtained with Fourier transform infrared (FTIR) spectroscopy, which can provide mainly qualitative analysis. The technique has proved to be promising for these compounds and will be applied to characterize several other chemically delithiated Li1-xCo1-yMyO2 (M = Cr, Mn, Fe, Ni, Cu, Mg, and Al) cathodes.