Search results for "Lithium"
showing 10 items of 680 documents
Nonlinear Disorder Mapping via Wave Mixing in poled Lithium Tantalate
2010
We introduce and test a simple approach for the characterization of domain distribution in bulk quadratic ferroelectric crystals, specifically periodically poled Lithium Tantalate with random mark-to space ratio.
Nonlinear Disorder Mapping via Three Wave Mixing in Poled Lithium Tantalate
2010
We introduce and test a simple approach for the characterization of domain distribution in bulk quadratic ferroelectric crystals, such as periodically poled Lithium Tantalate with random mark-to space ratio.
High voltage vacuum-processed perovskite solar cells with organic semiconducting interlayers
2020
In perovskite solar cells, the choice of appropriate transport layers and electrodes is of great importance to guarantee efficient charge transport and collection, minimizing recombination losses. The possibility to sequentially process multiple layers by vacuum methods offers a tool to explore the effects of different materials and their combinations on the performance of optoelectronic devices. In this work, the effect of introducing interlayers and altering the electrode work function has been evaluated in fully vacuum-deposited perovskite solar cells. We compared the performance of solar cells employing common electron buffer layers such as bathocuproine (BCP), with other injection mate…
Analysis of the thermo-mechanical behaviour of the DEMO Water-Cooled Lithium Lead breeding blanket module under normal operation steady state conditi…
2015
Within the framework of DEMO R&D activities, a research cooperation has been launched between ENEA, the University of Palermo and CEA to investigate the thermo-mechanical behaviour of the outboard equatorial module of the DEMO1 Water-Cooled Lithium Lead (WCLL) blanket under normal operation steady state scenario. The research campaign has been carried out following a theoretical-computational approach based on the Finite Element Method (FEM) and adopting a qualified commercial FEM code. In particular, two different 3D FEM models (Model 1 and Model 2), reproducing respectively the central and the lateral poloidal-radial slices of the WCLL blanket module, have been set up. A particular attent…
New insight on the lithium hydride–water vapor reaction system
2018
Abstract The reaction of lithium hydride (LiH) powder with pure water vapor (H2O and D2O) was studied by thermogravimetry and in situ infrared spectroscopy at 298 K over a large pressure range. The mean particle size of LiH is around 27 μm. At very low pressure, the hydrolysis starts with the formation of lithium oxide (Li2O). Then, both Li2O and lithium hydroxide (LiOH) are formed on increasing pressure, thus, creating a Li2O/LiOH bilayer. The reaction takes place through the consumption of LiH and the formation of Li2O at the LiH/Li2O interface and through the consumption of Li2O and the formation of LiOH at the Li2O/LiOH interface. Above 10 hPa, only the monohydrate LiOH·H2O is formed. T…
Physical and electrochemical properties of LiFePO4/C thin films deposited by direct current and radiofrequency magnetron sputtering
2011
Abstract In this study, LiFePO 4 /C thin films with various contents of carbon were prepared by direct current (DC), radiofrequency (RF) and combined (DC/RF) magnetron sputtering methods. Influences of the composition, morphology and microstructure on the electrochemical properties of LiFePO 4 /C thin films are investigated by studying charge–discharge curves, cyclic voltammetry and electrochemical impedance spectroscopy. Cyclic voltammogram of the LiFePO 4 /C thin film showed the typical redox reaction peaks characterizing the electrochemical lithium insertion/extraction reactions in LiFePO 4 . Obtained LiFePO 4 /C thin films have relatively high charge capacities (127 mAh g − 1 ). It was …
Synergistic Effects of Surface Coating and Bulk Doping in Ni-Rich Lithium Nickel Cobalt Manganese Oxide Cathode Materials for High-Energy Lithium Ion…
2022
Ni-rich layered oxide cathodes are promising candidates to satisfy the increasing energy demand of lithium-ion batteries for automotive applications. Thermal and cycling stability issues originating from increasing Ni contents are addressed by mitigation strategies such as elemental bulk substitution ("doping") and surface coating. Although both approaches separately benefit the cycling stability, there are only few reports investigating the combination of two of such approaches. Herein, the combination of Zr as common dopant in commercial materials with effective Li2 WO4 and WO3 coatings was investigated with special focus on the impact of different material processing conditions on struct…
Effects of Ionising Radiation on Optical Properties of Lithium Niobate Single Crystals
2005
Studies of thermal and γ-irradiation effects on the optical properties in congruent lithium niobate single crystals containing Mg and Gd dopants including samples with double dopants Y, Mg are reported. Formation of defects at irradiation and thermal treatment of the samples is explored by analysis of the behaviour of electron absorption spectra. Considerable increase of absorption with the dose of γ-radiation is observed at 500 nm. The changes of absorption examined under different conditions are explained by creation and destruction of Nb 4+ defects.
Dynamic heterogeneity in polymer electrolytes. Comparison between QENS data and MD simulations
2001
Abstract We have investigated the dynamics of poly(ethylene oxide) (PEO) lithium-based salt electrolytes (PEO–LiBETI) using quasi-elastic neutron scattering (QENS). Measurements were carried out on the spectrometer NEAT (HMI, Berlin) above the melting temperature of PEO ( T m ≈65°C). The experimental data fully support the Molecular Dynamics (MD)-derived model of a heterogeneous dynamics in dilute PEO-salt electrolytes. In agreement with MD simulations carried out on PEO–LiPF 6 , we find evidences for the existence of two dynamic processes: (a) a faster process that is described in terms of the pure PEO dynamics and (b) a second component which we identify with the slower motion of the PEO …
Electrochemical Fabrication and Physicochemical Characterization of Metal/High-k Insulating Oxide/Polymer/Electrolyte Junctions
2014
Photoelectrochemical polymerization of poly(3,4-ethylenedioxythiophene), PEDOT, was successfully realized on anodic film grown to 50 V on magnetron sputtered Ti-6 atom % Si alloys. Scanning electron microscopy allowed us to evidence formation of compact and uniform polymer layers on the oxide surface. Photoelectrochemical and impedance measurements showed that photopolymerization allows one to grow PEDOT in its conducting state, while a strong cathodic polarization is necessary to bring the polymer in its p-type semiconducting state. Information on the optical and electrical properties of metal/oxide/polymer/electrolyte junctions proves that PEDOT has promising performance as an electrolyte…