Solid Nickel Research Articles

Thermophysical properties of solid and liquid nickel near melting point

Thermophysical properties of solid and liquid nickel near melting point

Hollow nickel sources for improving nickel utilization in Zebra batteries

The Zebra (Na-NiCl2) batteries are regarded as a promising option for large-scale electrical energy storage due to their plentiful electrode material resources, high energy density, and safety features. In the cathode of Zebra battery, the nickel powders serve as both an active material and a conductive agent. In practice, its amount is significantly greater than its theoretical usage, often exceeding three times the theoretical amount. Hence, the presence of ultra-excessive nickel results in high material costs, posing obstacles to the wider implementation of Zebra batteries. To address this problem, we introduce hollow nickel source as active material to improve the nickel utilization in Zebra battery. In this work, we assemble Zebra batteries using nickel hollow spheres (NHS) with sizes of ∼200 nm, ∼500 nm, ∼1 μm and ∼ 5 μm as nickel source. The battery using NHSs with a size of 1 μm exhibits the best cycling performance and the lowest polarization voltage. By reducing the Ni(NHS, ∼1 μm)/NaCl mass ratio to 1.0, 60% theoretical capacity can be achieved after 170 cycles at 260 °C, which surpasses the traditional batteries using solid nickel source at the same Ni/NaCl ratio. This performance is comparable to that of traditional solid nickel sources with a mass ratio of 1.5 to NaCl. Therefore, using NHS as the nickel source in Zebra batteries reduces nickel usage by 33% without compromising performance.

One‐Step Synthesis and Deposition of Metal Oxides: NiO Quantum Dots as a Transport Layer for Perovskite Photovoltaics

One‐step synthesis and deposition of nickel oxide quantum dots using a gas‐phase microplasma process is demonstrated and their applicability as a transport layer for solar cell devices is shown. The process uses a solid nickel metal wire as sacrificial electrode, and the concentration of oxygen gas required in the synthesis is investigated. The quantum dots are characterized for physical, chemical, and optical properties and critical process parameters such as the process throughput are also estimated. Direct one‐step deposition directly on perovskite solar cells is carried out using a computer‐controlled x–y stage and the performance of the solar cell device is assessed.

Yolk–shell Ni–Co bimetallic nitride/oxide heterostructures as high‐performance electrode of all‐solid‐state supercapacitor

Hierarchical core–shell structure is benefit for the fast diffusion and bulk storage of electron/ion while metal nitrides (MN) exhibit metal‐like behavior with excellent conductivity. Herein, nickel cobalt glycerate solid spheres (NiCo‐G) and nickel cobalt glycerate yolk–shell structure (NiCo‐GYS) were successfully synthesized via solvothermal reactions, accompanied by annealing using urea as a cheap and convenient nitrogen source to obtain metal nitride/bimetallic oxide core–shell heterostructure (NiCoNO). Excellent specific capacitance of 1878 F g−1 at 1 A g−1 is displayed by the prepared NiCoNO. Amazingly, the distinct core–shell construction guarantees high stability during the charge/discharge operation. NiCoNO maintains an 83.9% specific capacitance after 5000 cycles at 10 A g−1. Furthermore, the all‐solid‐state hybrid supercapacitor was assembled using NiCoNO cathode and active carbon (AC) anode components. The device has an excellent capacitive retention rate of 81.1% after 5000 cycles at 10 A g−1 and a good energy density of 64.2 Wh kg−1 at a power density of 900 Wh kg−1. A light‐emitting diode (LED) bulb can be lighted for 3 min, indicating the promising practical application prospect of the supercapacitor.

Every Step Counts: Importance of Final ALD Sequences for Oxygen Evolution Reaction Catalysts

In achieving the global dream of a sustainable future, the development of new and alternative methods to generate electricity are of high importance. Current renewable energy sources are mainly dependent on sun and wind, and are thus very unpredictable. To obtain an overall reliable energy supply, we need to be able to store clean energy for extended periods of time to compensate for unfavorable weather conditions or sudden surges in energy demand.One way to store energy is by generating H2-gas, which has a set of interesting advantages as an energy carrier molecule. It has a very high energy density, is multifunctional as feedstock or energy carrier and it is not a greenhouse gas in itself. The production efficiency of green H2, however, still needs to be optimized before it can be adapted on a global scale. Electrochemical water splitting is mainly hampered by the sluggish kinetics of the oxygen evolution half-reaction (OER) of the process. This involves a transfer of four electrons, each with its own intermediary product(s) requiring catalysis, resulting in a significant overpotential[1].Atomic layer deposition (ALD) could be an interesting technique in the research, development and possibly production of such OER catalytic materials. This technique is suited to deposit thin films in a controlled layer-by-layer way with dimension control up to the Angström level. In this development, transition metals could be interesting catalyst candidates due to their availability and pricing over tradition OER catalysts based on noble metals [2]. Both oxides and phosphate variants have been explored; the latter occasionally outperforming the former[3][4].Nickel has shown to be one of the more OER-active transition metals, and doping or combining it with iron seems to further increase its performance [5]. Inspired by these results, ALD was used in this work to deposit and finetune the properties of a Ni-Fe ternary phosphate for its use as an OER-catalyst material. This material was deposited by alternating ALD cycles of Ni- and Fe-phosphate (denoted here as NiPO and FePO) based on previous works of Rongé et al.[6] and Henderick et al.[7].Ni-Fe phosphates with varying composition and thickness were deposited on a solid nickel disc and tested in a rotating-disc electrode (RDE) set-up to quantify their electrochemical performance. Applying a coating with a selected composition of 4 NiPO to 1 FePO cycles improves the performance over a bare Ni-PVD substrate (Fig 1). A current density of 91 mA/cm2 at 0.685 V vs Hg/HgO is obtained for this material which is 75% higher than the uncoated nickel disk (51 mA/cm2) which indicates that the material has catalytic properties for the OER increasing the production of H2 at an identical overpotential. An additional observation was that the pulsing order of the two sub-processes within an ALD super-cycle has an important impact on the resulting layer’s performance. If the FePO sub-cycle is pulsed last, the current density increases further to approx. 150 mA/cm2 for a total increase of 200% compared to the uncoated performance.The results of this explorative work in the use of ALD for the development of OER catalytic materials indicate that it is a promising technique due to the precise control that can be exerted over both the thickness and composition of the material. Specifically the option to exert high control over the surface of the catalyst can be a big asset in researching catalytic materials.

Electrochemical and metallographic characterization of Ni-NiO-NiBi3 equilibrium in molten lead-bismuth eutectic

This study aims to investigate the chemistry of the Ni-O-Pb-Bi system through a combined microscopic and electrochemical analysis of the Ni-NiO-NiBi3 equilibrium in molten lead-bismuth eutectic (LBE). Through SEM-EDX metallographic characterization, we examined to the precipitates formed on the solid nickel substrate in molten LBE, confirming the formation of the NiBi3 within the temperature range of 469–748 K. Subsequently, we induced the Ni(LBE)-NiO(s)-NiBi3(s) ternary equilibrium in LBE and measured the equilibrium oxygen concentrations at different temperatures. The equilibrium nickel activity was derived using the measured equilibrium oxygen concentration in the temperature range of 518–595 K. Finally, the Ni-Bi IMCs floating on LBE at the end of the measurements were collected and characterized by X-ray diffraction (XRD), confirming the presence of the NiBi3 phase.

Surface chemistry analysis of acidified and nickel impregnated carbon for desulfurization of fuels

Emission norms tend to reduce sulfur content in transport fuels to 10ppm. Considering this new method like adsorptive desulfurization are widely researched. The main motive in adsorptive desulfurization is to selectively adsorb Dibenzothiophene (DBT) and 4,6-DimethylDBT. Considering this adsorbent with nickel impregnation and acidic surface functionalities were developed. Topographical and surface chemical features were studied of developed carbon adsorbents. Presence of carboxylic surface functionalities and reduced solid nickel was confirmed on adsorbents surfaces. In addition to this formation of nickel complexes due to neutralization of nickel ion and carboxylic groups was confirmed. This type of adsorbents can act as potential adsorbents for adsorption of DBT and 4,6-dimethyl DBT.

Inhibiting the Leidenfrost Effect by Superhydrophilic Nickel Foams with Ultrafast Droplet Permeation.

Inhibiting the Leidenfrost effect has drawn extensive attention due to its detrimental impact on heat dissipation in high-temperature industrial applications. Although hierarchical structures have improved the Leidenfrost point to over 1000 °C, the current performance of single-scale structures remains inadequate. Herein, we present a facile high-temperature treatment method to fabricate superhydrophilic nickel foams that demonstrate ultrafast droplet permeation within tens of milliseconds, elevating the Leidenfrost point above 500 °C. Theoretical analysis based on the pressure balance suggests that these remarkable features arise from the superhydrophilic property, high porosity, and large pore diameter of nickel foams that promote capillary wicking and vapor evacuation. Compared to solid nickel surfaces with a Leidenfrost temperature of approximately 235 °C, nickel foams nucleate boiling at high superheat, triggering an order of magnitude higher heat flux. The effects of the pore diameter and surface temperature on droplet permeation behaviors and heat transfer characteristics are also elucidated. The results indicate that droplet permeation is dominated by inertial and capillary forces at low and high superheat, respectively, and moderate pore diameters are more conducive to facilitating droplet permeation. Furthermore, our heat transfer model reveals that pore diameter plays a negligible role in the heat flux at high surface temperatures due to the trade-off between effective thermal conductivity and specific surface area. This work provides a new strategy to address the Leidenfrost effect by metal foams, which may promise great potential in steel forging and nuclear reactor safety.

Flow Development and Entrainment in Turbulent Particle‐Laden Jets

AbstractExplosive eruptions expel volcanic gases and particles at high pressures and velocities. Within this multiphase fluid, small ash particles affect the flow dynamics, impacting mixing, entrainment, turbulence, and aggregation. To examine the role of turbulent particle behavior, we conducted an analogue experiment using a particle‐laden jet. We used compressed air as the carrier fluid, considering turbulent conditions at Reynolds numbers from approximately 5,000 to 20,000. Two different particles were examined: 14‐μm diameter solid nickel spheres and 13‐μm diameter hollow glass spheres. These resulted in Stokes numbers between 1 and 35 based on the convective scale. The particle mass percentage in the mixture is varied from 0.3% to more than 20%. Based on a 1‐D volcanic plume model, these Stokes numbers and mass loadings corresponded to millimeter‐scale particle diameters at heights of 4–8 km above the vent during large, sustained eruptions. Through particle image velocimetry, we measured the mean flow behavior and the turbulence statistics in the near‐exit region, primarily focusing on the dispersed phase. We show that the flow behavior is dominated by the particle inertia, with high Stokes numbers reducing the entrainment by more than 40%. When applied to volcanic plumes, these results suggest that high‐density particles can greatly increase the probability of column collapse.

Chemical speciation changes of an all-solid-state lithium-ion battery caused by roasting determined by sequential acid leaching

All-solid-state lithium-ion batteries (ASS-LIBs) are expected to replace current liquid-based LIBs in the near future owing to their high energy density and improved safety. It would be preferable if ASS-LIBs could be recycled by the current recycling processes used for liquid-based LIBs, but this possibility remains to be determined. Here, we subjected an ASS-LIB test cell containing an argyrodite-type solid electrolyte (Li6PS5Cl) and nickel–manganese–cobalt-type active material (Li(Ni0.5Mn0.3Co0.2)O2) to roasting, a treatment process commonly used for recycling of the valuable metals from liquid-based LIBs, and investigated the changes in chemical speciation. Roasting was performed at various temperatures (350–900 °C), for various times (60–360 min), and under various oxygen fugacity (air or O2) conditions. The chemical speciation of each metal element after roasting was determined by sequential elemental leaching tests and X-ray diffraction analysis. Li formed sulfates or phosphates over a wide temperature range. Ni and Co followed very complicated reaction paths owing to coexistence of S, P, and C, and they formed sulfides, phosphates, and complex oxides. The optimum conditions for minimizing formation of insoluble compounds, such as complex oxides, were a roasting temperature of 450–500 °C and a roasting time of 120 min. The results indicated that although ASS-LIBs can be treated by the same roasting processes as those used for current liquid-based LIBs, the optimal roasting conditions have narrow ranges. Thus, careful process control will be needed to achieve high extraction percentages of the valuable metals from ASS-LIBs.

PROGRESS IN NICKEL TARGET DESIGNS FOR DEUTERON IRRADIATION: A MILESTONE IN RADIOISOTOPE PRODUCTION OPTIMIZATION

Medical radioisotopes play significant roles in nuclear medicine, particularly in tumor diagnosis and its therapy. Optimization in production of these important isotopes is very essential for the overall health of the target patients. In this work, we analyzed general trends in the use of various forms of nickel metal as target for radioisotopes production in nuclear accelerators. A careful study of all previously used forms of nickel metal in the literature up to 2016 indicate that different physical forms of the metal, such as its very high purity and impure forms, alloys, compounds and powdered forms have, over the years, been used for various radioisotope productions under deuteron irradiation route, each providing different production effect. The excitation functions of several useful radioisotopes could be studied under deuteron irradiation of nickel. In a recent experimental work by the authors, some very pure, thin nickel foils of natural isotopic composition were also used in form of stacked arrangement for deuteron irradiation. The study found that most of the recent studies on radioisotopes production cross sections use very high purity and solid nickel forms.

Solid waste-supported nickel nanoparticles: A sustainable, recoverable, and efficient heterogeneous catalyst for organic pollutant degradation

The processing of polymeric solid wastes into industrial processes is of outmost importance from an environmental and economic point of view. Herein, a simple and straightforward route was developed for immobilizing nickel nanoparticles on the surface of waste loose fill as a recoverable heterogeneous catalyst. The nickel nanoparticles exhibited a spherical-like shape and were not uniformly dispersed in the loose fill matrix. The carbonyl and/or carboxyl groups would initiate active sites along the loose fill chains, which serve as adsorption centers and tight fixing of nickel ions. The catalytic activity of nickel@loose fill nanocomposite was evaluated through the degradation of 4-nitrophenol, reactive blue dye, and mixture of both. The results indicated the catalyst retained 87% of its activity after 20 cycles. The use of a solid waste as a supporting matrix in heterogeneous catalysis may reduce the fabrication cost and improve the contact between the reactants and Ni nanoparticles due to the porosity of loose fill. The use of waste material made from renewable resources (vegetable starch) could explore genuinely and sustainable materials as alternatives to the traditional polymers in heterogeneous catalysis.

MOLECULAR DYNAMICS SIMULATION OF MOLTEN NiF<sub>2</sub>: STRUCTURE AND TRANSPORT PROPERTIES

Computer modeling of molten nickel fluoride was carried out using classical molecular dynamics in the temperature range 1750–1900 K. The density of crystalline NiF2 with a relative error of less than 1% verified the parameters of the pair potential obtained in the framework of the quantum-chemical approximation. The calculated radial distribution functions and coordination numbers for the Ni–F pair indicate a distorted octahedral environment of the nickel cation in the melt. In this case, a slight decrease in the nearest cation-anion distance was found in comparison with solid nickel fluoride. It is shown that the curve of the radial distribution function for the fluorine-fluorine pair near the main peak splits into two maxima. The position of the first peak at 2.67 Å is characterized by a coordination number of 5.1 and describes neighboring anions in a distorted octahedron. Whereas, the second maximum can be associated with fluorine anions located along the F–Ni–F line with a peak position at 3.83 Å, which indicates a decrease in a similar distance compared to the crystal. The coefficients of self-diffusion of ions and the viscosity of the NiF2 melt at different temperatures were calculated.

Molecular-Dynamical Investigation of Thermomechanical Properties of Spherical Solid and Hollow Nickel Nanopowder during Laser Additive Manufacturing Process

Molecular dynamics (MD) simulation with the embedded-atom method (EAM)/alloy potential is used to investigate the property of the nanoscale hollow spherical Nickel (Ni) powder during the laser additive manufacturing (AM) process. The thermomechanical properties of the Ni nanopowder is also explored (1) at room temperature and (2) from room temperature to the melting temperature during laser AM of powder bed fusion. As a result, the optimum parameters for the laser AM process are proposed. The optimal coalescence temperature of the nanoscale hollow spherical Ni powder is in the range between 980 and 1421K, while the melting temperature is in the range between 1320 and 1470 K. The coalescence and melting temperatures are lower than the melting point of Ni (1728 K).

PROGRESS IN NICKEL TARGET DESIGNS FOR DEUTERON IRRADIATION: A MILESTONE IN RADIOISOTOPE PRODUCTION OPTIMIZATION

Medical radioisotopes play significant roles in nuclear medicine, particularly in tumor diagnosis and its therapy. Optimization in production of these important isotopes is very essential for the overall health of the target patients. In this work, we analyzed general trends in the use of various forms of nickel metal as target for radioisotopes production in nuclear accelerators. A careful study of all previously used forms of nickel metal in the literature up to 2016 indicate that different physical forms of the metal, such as its very high purity and impure forms, alloys, compounds and powdered forms have, over the years, been used for various radioisotope productions under deuteron irradiation route, each providing different production effect. The excitation functions of several useful radioisotopes could be studied under deuteron irradiation of nickel. In a recent experimental work by the authors, some very pure, thin nickel foils of natural isotopic composition were also used in form of stacked arrangement for deuteron irradiation. The study found that most of the recent studies on radioisotopes production cross sections use very high purity and solid nickel forms.

Broken-symmetry self-consistent GW approach: Degree of spin contamination and evaluation of effective exchange couplings in solid antiferromagnets

We adopt a broken-symmetry strategy for evaluating effective magnetic constants J within the fully self-consistent GW method. To understand the degree of spin contamination present in broken-symmetry periodic solutions, we propose several extensive quantities demonstrating that the unrestricted self-consistent GW preserves the broken-symmetry character of the unrestricted Hartree-Fock solutions. The extracted J are close to the ones obtained from multireference wave-function calculations. In this paper, we establish a robust computational procedure for finding magnetic coupling constants from self-consistent GW calculations and apply it to solid antiferromagnetic nickel and manganese oxides.

Facile fabrication of carbon nanotubes-encapsulated cobalt (nickel) salt nanocomposites and their highly efficient catalysis in the thermal degradation of ammonium perchlorate and hexogen

For reducing particle aggregation and improving catalytic activities of metal salts in composite solid propellants, ten cobalt and nickel compounds were encapsulated into the channels of oxidized carbon nanotubes (CNTs) by ultrasonication, which was proven by TEM, SEM, XRD, Raman, XPS, etc. The catalytic performances of the nanocomposites for ammonium perchlorate (AP) and hexogen (RDX) thermal degradation were evaluated by the DSC technique and the results revealed that the composites exhibit significant effects on the thermal decomposition of AP and RDX. Among them, 5 wt. % Co(NO3)2@CNTs(D1) as the catalyst increased the released heat of AP from 746.53 J/g to 2489.26 J/g, higher in catalytic efficiency than CoO@CNTs(D1) (1791.29 J/g), and advanced the peak temperature of AP at the high-temperature decomposition stage from 406.6°C to 312.4°C; while 1 wt. % Ni(NO3)2@CNTs(D1) as an additive enhanced the pyrolytic heat of RDX approximately three times and was more active than that of NiO@CNTs(D1). Kinetic studies showed that the activation energies of AP and RDX were sharply decreased with Co(NO3)2@CNTs(D1) and Ni(NO3)2@CNTs(D1) as additives. In addition, the thermal decomposition mechanism of RDX was studied by TG-FTIR-MS and it was found that the as-prepared nanocomposites promoted the cleavage of the C-N bonds of RDX and the generation of N2O gas.

Controlled preparation of Ni–Cu alloy catalyst via hydrotalcite-like precursor and its enhanced catalytic performance for methane decomposition

Composition-uniform Ni–Cu/Al2O3 alloy catalysts have been prepared from Ni–Cu–Al hydrotalcite-like compounds (HTlcs) and tested for methane decomposition at 650°C. The catalysts were characterized by XRD, XPS, H2 chemisorption, H2-TPR, STEM-EDX, SEM, TEM, and Raman. The characterizations reveal that calcination of Ni–Cu–Al HTlcs leads to Ni(Cu,Al)O oxide solid solution, both nickel and copper ions being homogeneously distributed in HTlcs as well as in Ni(Cu,Al)O, and upon reduction the well-mixed Cu2+/Ni2+ species are step-wise reduced to form composition-uniform Ni–Cu alloy with an average size of 9.5–10.4 nm. Alloying Ni with an appropriate amount of Cu remarkably enhances the catalytic life and carbon yield. The highest carbon yield of 132.9 g-C/g-cat is obtained at atomic ratio of Ni:Cu = 7:3, which is about 78 times that of the Ni/Al2O3 counterpart. Moreover, carbon morphology is changed from thin CNTs to thick fishbone-CNFs and platelet-CNFs depending on the copper content. Under the reaction atmosphere, Ni–Cu alloy is sintered to large particles by contact with methane. It is suggested that Ni–Cu alloying favors the formation of large alloy particles, which inhibits methane dissociation and enhances carbon bulk diffusion, thus facilitating the CNFs growth and leading to a significant increase of carbon yield.

Preparation of adsorbent from nickel slag for removal of phosphorus from glyphosate by-product salt

ABSTRACT In this paper, nickel slag was used as raw material to hydrothermally synthesize zeolite and modified to prepare a phosphorus adsorbent. The adsorbent was characterized by XRD, FT-IR, SEM, and EDS. The effects of adsorbent dosing, contact time, dosing volume, and initial concentration of solution on the adsorption effect were investigated. The results showed that the adsorbent had good adsorption performance at the optimum dosage of 8 g/L and at the solution pH at 3–11. The adsorption kinetics were in accordance with the pseudo-first-order kinetic model, and the adsorption equilibrium was reached at a contact time of 30 min, and the maximum adsorption capacity was predicted by Langmuir to be 16.61 mg/g. Therefore, the study not only effectively used industrial solid waste nickel slag to prepare adsorbents, but also effectively removed phosphorus in real water.

Electrochemical Behaviors of Consumable Ti2CO@Al2O3 Anode for Ti Extraction by USTB Process

USTB technology is widely considered as a low-cost and environmentally-friendly method for titanium extraction from a consumable TiCxOy anode. It is expected to directly prepare TiCxOy by selective carbothermal reduction of titanium ores, not pure TiO2. However, impurities in titanium ores, particularly Al2O3, may affect the electrochemical dissolution of TiCxOy and Ti extraction. In this work, the effects of Al2O3 impurity on the preparation and dissolution behaviors of Ti2CO are studied. It is found that the existence form of Al2O3 is not changed during carbothermal reduction. With the increase of Al2O3 content, the conductivity of Ti2CO anode slightly decreases from 143.1 to 131.6 S cm−1 and the anodic polarization curves of Ti2CO@Al2O3 shifts to the positive direction due to the increase of dissolution resistances. Al2O3 in Ti2CO@Al2O3 anode will drop into molten salts to form anode slime during USTB process. On both liquid Zn and solid nickel cathodes, Ti is electrodeposited, which is not affected by Al2O3 impurity. Therefore, it is confirmed that typical Al2O3 impurity has no obvious effect on the electrochemical dissolution of Ti2CO anode and Ti extraction. The advanced USTB process is expectedly developed by the selective carbothermal reduction of titanium ores to prepare Ti2CO anode.