Search results for "litium"
showing 9 items of 29 documents
Conjugation with carbon nanotubes improves the performance of mesoporous silicon as Li-ion battery anode
2020
Carbon nanotubes can be utilized in several ways to enhance the performance of silicon-based anodes. In the present work, thermally carbonized mesoporous silicon (TCPSi) microparticles and single-walled carbon nanotubes (CNTs) are conjugated to create a hybrid material that performs as the Li-ion battery anode better than the physical mixture of TCPSi and CNTs. It is found out that the way the conjugation is done has an essential role in the performance of the anode. The conjugation should be made between negatively charged TCPSi and positively charged CNTs. Based on the electrochemical experiments it is concluded that the positive charges, i.e., excess amine groups of the hybrid material i…
Effect of lithium ions on the catalytic efficiency of calcium oxide as a nanocatalyst for the transesterification of lard oil
2019
The present work encompasses the effect of Li+ ions on CaO nanoparticles for the transesterification of lard oil. The modification of CaO nanoparticles was achieved by the impregnation of different molar ratios of lithium hydroxide. Later, each catalyst was screened for the catalytic conversion of lard oil to a fatty acid methyl ester (FAME). The nanocatalyst CaO–0.5LiOH (1 : 0.5 molar ratio) showed the best conversion rate for FAME. The synthesized nanocatalyst was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis, and Hammett indicato…
Expansion and Compression of a Helicate with Central Diol-Units as Stereocontrolling Moieties
2022
The dicatechol ester ligand 2-H4 forms the compressed helicate Li4[(2)3Ti2] which upon removal of the internally bound lithium cations expands. In the compressed form, the chiral diol units control the stereochemistry of the complex which is lost upon expansion of the system. peerReviewed
Resonance Excitations in 7Be(d,p)8Be* to Address the Cosmological Lithium Problem
2022
The anomaly in lithium abundance is a well-known unresolved problem in nuclear astrophysics. A recent revisit to the problem tried the avenue of resonance enhancement to account for the primordial 7Li abundance in standard big-bang nucleosynthesis. Prior measurements of the 7Be(d,p)8Be∗ reaction could not account for the individual contributions of the different excited states involved, particularly at higher energies close to the Q value of the reaction. We carried out an experiment at HIE-ISOLDE, CERN to study this reaction at Ec.m.=7.8 MeV, populating excitations up to 22 MeV in 8Be for the first time. The angular distributions of the several excited states have been measured and the con…
Effects of Lithium Source and Content on the Properties of Li-Rich Layered Oxide Cathode Materials
2023
Lithium-rich layered oxide (LLO) are considered high-capacity cathode materials for next-generation lithium-ion batteries. In this study, LLO cathode materials were synthesized via the hydroxide coprecipitation method followed by a two-step lithiation process using different lithium contents and lithium sources. The effects of lithium content and lithium source on structure and electrochemical performance were investigated. This study demonstrated the clear impact of Li/TM ratio on electrochemical performance. Lower Li/TM ratio reduced the irreversible capacity loss in the first cycle and provided better cycling stability among all samples. The best results exhibited an initial discharge ca…
Probing the Extremes of Covalency in M-Al bonds: Lithium and Zinc Aluminyl Compounds.
2022
Synthetic routes to lithium, magnesium, and zinc aluminyl complexes are reported, allowing for the first structural characterization of an unsupported lithium-aluminium bond. Crystallographic and quantum-chemical studies are consistent with the presence of a highly polar Li-Al interaction, characterized by a low bond order and relatively little charge transfer from Al to Li. Comparison with magnesium and zinc aluminyl systems reveals changes to both the M-Al bond and the (NON)Al fragment (where NON=4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene), consistent with a more covalent character, with the latter complex being shown to react with CO<sub>2</sub> vi…
Considering lithium-ion battery 3D-printing via thermoplastic material extrusion and polymer powder bed fusion
2021
In this paper, the ability to 3D print lithium-ion batteries through thermoplastic material extrusion and polymer powder bed fusion is considered. Focused on the formulation of positive electrodes composed of polypropylene, LiFePO4 as active material, and conductive additives, advantages and drawbacks of both additive manufacturing technologies, are thoroughly discussed from the electrochemical, electrical, morphological and mechanical perspectives. Based on these preliminary results, strategies to further optimize the electrochemical performances are proposed. Through a comprehensive modeling study, the enhanced electrochemical suitability at high current densities of various complex three…
Effect of Reaction Conditions on the Coprecipitation of Ni(OH)2 for Lithium-Ion Batteries
2023
Electrochemical performance of cathode active materials (CAMs) is dependent on the properties of coprecipitated precursors (pCAMs). This is a sensitive process affected by several reaction parameters such as temperature, pH, concentration of reactants, agitation rate, and residence time. In this paper, the effect of parameters influencing the particle size growth and the physical properties, such as particle morphology and tapped density, was studied in the coprecipitation of Ni(OH)2. Formation of a homogeneous population with narrow particle size distribution was observed, followed by a more heterogeneous population of dense particles. Ammonia concentration and residence time had significa…
Kaustisen seutukunnan kaivos- ja tuulivoimahankkeiden taloudellisten kokonaisvaikutusten ennakkoarviointi
2019
Kaustisen seutukunnassa on lähivuosina käynnistymässä neljä uutta luonnonvarojen hyödyntämiseen tähtäävää suurhanketta – litiumkaivoshanke Kaustisella ja tuulivoimapuistohankkeet Halsualla, Lestijärvellä ja Toholammilla. Hankkeiden investointiarvo on koko laajuudessaan jopa 1,5 miljardia euroa ja pysyvät työvoimavaikutukset vähintään satoja henkilötyövuosia. Tämän raportin tarkoituksena on esittää laskelmia näiden suurhankkeiden taloudellisista kokonaisvaikutuksista. Laskelmat tukevat omalta osaltaan sitä työtä, jolla pyritään varmistamaan, että investoinnit tuottaisivat mahdollisimman paljon lisäarvoa elinkeinoelämän kasvuun ja kuntien talouden parantumiseen seutukunnassa. Laskelmien tarko…