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Photoablation products arising from polymer materials were examined by supersonic beam spectrometry, and the results are compared with those obtained by thermal decomposition. The high selectivity provided by supersonic beam spectrometry allows detection of minor species, e.g., styrene occurred from poly(α-methylstyrene) by cleavage of a methyl group and by proton rearrangement. Because ablation techniques involve high temperatures, thermally stable materials such as poly(p-methylstyrene) can be examined. The latter material is difficult to examine by thermal decomposition, even at 350 °C. It is also possible to differentiate between isomer ablation products, e.g., α-methylstyrene and p-methylstyrene. The instrumental setup described herein was used to examine several authentic samples, such as ABS resin (acrylonitrile-butadiene-styrene) and O-ring (SBR, styrene-butadiene rubber), as well as polystyrene foam. As a result, a styrene segment could be confirmed to be present in these materials. However, no evidence was found for its presence in a glue sample that was suspected to contain styrene on the basis of conventional mass spectrometry. The latter finding confirms the high degree of selectivity of the technique.

The influence of the electrolyte structure on the Ca 2+ ion insertion and extraction properties of V 2 O 5 was studied by changing the electrolyte concentration or solvent. The electrolyte structure was analyzed by Raman spectroscopy. The most significant changes were found in the molar ratio of the contact ion pair (CIP) in the total ionic species. Among the various electrolytes, 0.3 M Ca(TFSI) 2 dissolved in ethylene carbonate and dimethyl carbonate (0.3 M EC:DMC) and 0.5 M Ca(TFSI) 2 dissolved in triglyme (0.5 M G3) have relatively small molar ratios of CIPs. The electrochemical performance was strongly related to the molar ratio of the CIPs. A high coulombic efficiency and high capacity were observed when using 0.3 M EC-DMC. Moreover, 0.5 M G3 showed the highest capacity despite its low coulombic efficiency. This could be related to the formation of solvent-separated ion pairs (SSIPs) due to the low polarity of G3 and its solvation form that encapsulates Ca 2+. SSIPs had a reductively unstable character as that of the CIPs. Surface analysis revealed that the thinner the surface film produced, the lower the CIP content. This was deemed responsible for the rate performance enhancements, given the potential electrochemical instability of the Ca-containing CIPs.

Abstract.Carbon composites of open-framework iron fluoride (FeF3·0.33H2O/C) was investigated as a new cathode material for calcium ion batteries for the first time. FeF3·0.33H2O/C delivers a relatively large capacity of ca. 110mAhg -1 . Its reversible capacity was greatly improved over non-composite FeF3·0.33H2O. During the first discharge and dischargecharge, insertion/extraction of Ca 2+ into/from FeF3·0.33H2O/C were confirmed by an ex-situ X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX) analysis. From the ex-situ analysis results, it was confirmed that Ca 2+ was inserted and extracted with redox of Fe.

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