The structure of sulfur-poly(acrylonitrile)-based Li-sulfur
batteries
is elucidated and correlated with the electrochemical performance
of such devices. Apart from the poly(acrylonitrile)-derived backbone,
thioamide as well as poly(sulfide) structures are proposed. Furthermore,
the intermediary formation of S8 during cycling and the
role of the electrolyte in its reintegration during charging into
are addressed. In summary, a comprehensive picture of the chemistry
and electrochemistry of Li-sulfur batteries is presented.
The optical properties of single crystals of strontium barium niobate, grown from the congruently melting composition and doped with different amounts of europium, are investigated. Absorption and emission spectra are measured in the visible and infrared spectral regions at different temperatures. From the spectra, conclusions on the structural sites can be drawn, revealing the major occupations of the B1 and B2 sites, and a minor one of the A2 site. The data are used to calculate crystal-field parameters for the mainly occupied site. A Judd-Ofelt analysis shows that the radiative quantum efficiency is approximately 70%. Furthermore, the influence of europium doping on the phase-transition temperature is determined.
Microscopic investigations of UV-induced formation of laser damage on LiB(3)O(5) optical surfaces during long-term sum-frequency generation (SFG) uncovers a significant growth of a SiO(2)-amorphous layer spatially limited to the illuminated area. The layer gives rise to a catastrophic break-down of the LiB(3)O(5)-output surface upon long-term laser operation even at intensities far below the laser-induced damage threshold. The interaction of UV laser light, LiB(3)O(5) surface and foreign atoms in the ambient atmosphere is discussed in the frame of a two-step process for surface-damage formation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.