Formation Of Li0 Research Articles

The Synthesis, Properties, and Stability of Lithium-Containing Nanostructured Nickel-Doped Ceramics.

Lithium-containing ceramics have several great potential uses for tritium production, as well as its accumulation. However, their use is limited due to their poor resistance to external influences, mechanical pressure, and temperature changes. In this work, initial nanostructured ceramic powders were obtained using the sol-gel method, by mixing TiO2 and LiClO4·3H2O with the subsequent addition of NiO nanoparticles to the reaction mixture; these powders were subsequently subjected to thermal annealing at a temperature of 1000 °C for 10 h. Thermal annealing was used to initiate the phase transformation processes, and to remove structural distortions resulting from synthesis. During the study, it was found that the addition of NiO nanoparticles leads to the formation of solid solutions by a type of Li0.94Ni1.04Ti2.67O7 substitution, which leads to an increase in the crystallinity and structural ordering degree. At the same time, the grain sizes of the synthesized ceramics change their shape from rhomboid to spherical. During analysis of the strength characteristics, it was found that the formation of Li0.94Ni1.04Ti2.67O7 in the structure leads to an increase in hardness and crack resistance; this change is associated with dislocation. When analyzing changes in resistance to cracking, it was found that, during the formation of the Li0.94Ni1.04Ti2.67O7 phase in the structure and the subsequent displacement of the Li2TiO3 phase from the composition, the crack resistance increases by 15% and 37%, respectively, which indicates an increase in the resistance of ceramics to cracking and the formation of microcracks under external influences. This hardening and the reinforcing effect are associated with the replacement of lithium ions by nickel ions in the crystal lattice structure.

On the Formation of Clusters of Li8 in Molten Solutions of LiCl-Li

Numerous base metals can be obtained via electrolytic reduction of their respective oxides in molten LiCl-Li2O electrolytes. In these processes, often times, Li+ is co-reduced to metallic Li. The formation of Li0 is undesirable and leads to a loss of current efficiency and therefore is of significant interest. In spite of its importance, molten mixtures of LiCl and Li are still poorly understood and previous research has demonstrated a variety of phenomena that are seemingly unexplainable. We have custom built a unique setup to conduct in-situ Raman spectroscopy of such molten mixtures. In this work, we show that a Raman active phase forms in the fused salt when Li is electrochemically reduced from Li2O in LiCl. The spectrum was comprised of three fundamental features at 285.5, 302.8, and 318.2 cm-1, with overtones of decreasing intensity at approximately integer multiples of these Raman shifts as Shown in Figure 1. This spectrum was found to be consistent with previously-reported characteristic spectrum of the lithium cluster Li8. The presence of a colloidal suspension of lithium clusters in the molten salt is hypothesized to be the reason behind anomalous physical behavior of LiCl-Li solutions. Acknowledgements: This work was performed under the auspices of the Department of Energy (DOE) through grant DE-NE0008262, and the US Nuclear Regulatory Commission (NRC) under contracts NRCHQ-11-G-38-0039, NRC-38-10-949 and NRC-HQ-13-G-38-0027. Mr. Kenny Osborne serves as the program manager for the DOE awards and Ms. Nancy Hebron-Isreal serves as the grants program officer for the NRC awards. Figure 1

Synthesis, Characterization, and Exchange Bias Effect in Single Crystalline Li0.44MnO2 Nanoribbons

Single crystalline Li0.44MnO2 nanoribbons are synthesized via the Na0.44MnO2 nanoribbons precursor template in LiNO3−LiCl eutectic molten salt. Li0.44MnO2 and Na0.44MnO2 nanoribbons are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy techniques. The influences of reaction temperature on the formation of Li0.44MnO2 nanoribbons have also been discussed. Magnetization measurements show that Li0.44MnO2 nanoribbons exhibit interesting exchange bias effects and the magnitude of exchange bias field can be tuned by the strength of the cooling field. The magnetic behaviors of Li0.44MnO2 nanoribbons can be interpreted based on a core−shell model.

Thermal decomposition, phase evolution, sintering and characterization of lithium titanate synthesized by sol-gel process

Lithium titanate powder was prepared by evaporation of an aqueous suspension obtained in reaction between lithium nitrate (LiNO3) and titanium hydroxide, formed by the hydrolysis of titanium tetrabutoxide Ti(C4H9O)4. Thermal decomposition and phase evolution behaviour of the dried powder were studied using TG-DTA and XRD, while powder characteristics (crystallite size, agglomerate size and morphology) were studied using X-ray diffraction, laser light scattering and SEM techniques. The synthesized powder exhibited loss in weight accompanied by corresponding heat effects in stages up to 550?C, transformed into an amorphous lithium titanate (Li2TiO3) compound and finally underwent crystallization at temperatures ranging from 550 to 650?C (accompanied by an exotherm at the DTA pattern). The powder formed at 650?C was found to be nanocrystalline (crystallite size ~10 nm), while the crystallites grew to 50 nm with increasing temperature to 1000?C. Both SEM and particle size data confirmed that the calcined powder consists of agglomerates with the mean size of ~3 ?m. Study of the powder sintering behaviour showed that densification and grain growth were very intensive during heat treatment up to 1050?C. Sintering at 1200?C led to loss of lithium and formation of Li0.14TiO2 phase. Thus, fine grained Li2TiO3 bodies with density higher than 85% TD, required for tritium breeding in ITER (International thermonuclear experimental reactor) application, can be formed by sintering of the prepared powder at temperature of 1050?C.

Electroreduction of Polyparaphenylene in LiClO4-Ethylene Carbonate Electrolyte

Polyparaphenylene powders are electrochemically reduced in LiCIO4-ethylene carbonate electrolyte. Intercalation of Li+ ions occurs and leads to the formation of Li0.5(C6H4) compounds. Side reactions due to the electrolyte decomposition are responsible for the important irreversible electrochemical capacity observed during the first charge-discharge cycles. The degradation products were analyzed by TEM and EELS between 2.85 and 0.75 V.