Ni Sn Alloys Research Articles

A novel approach to calculate diffusion matrix in ternary systems: Application to Ag–Mg–Mn and Cu–Ni–Sn systems

Diffusion behavior is of fundamental importance in material science and engineering. As a result, extensive attention has been paid to develop methodologies for obtaining the composition-dependent interdiffusivities. The present work proposed a novel approach with two steps to extract the interdiffusion coefficients from a single ternary diffusion couple. The concept of basis function is introduced, and this novel method is based on the utilization of both finite element method and optimization algorithm. Utilizing eight groups of diffusion couples together with electron probe microanalysis technique, the composition-dependent interdiffusion coefficients in fcc Ag–Mg–Mn alloys at 973 and 1073 K were determined via both the present method and Matano-Kirkaldy method. A home-made code is written to implement the novel numerical approach. The obtained interdiffusion coefficients based on the present method agree with the reliable ones from the Matano-Kirkaldy method better than previous methods for fcc Ag–Mg–Mn alloys in the present work as well as fcc Cu–Ni–Sn alloys from the literature, especially for the main interdiffusivities. In most cases, the presently computed main interdiffusivities by means of the composition-dependent diffusivities agree with the reliable ones from the Matano-Kirkaldy method within 50%. Besides, the sign of cross interdiffusivities using this novel method is usually the same as that from the Matano-Kirkaldy method. Such a high calculation precision and efficiency cannot be obtained using previous methods.

Inorganic Gel-Derived Metallic Frameworks Enabling High-Performance Silicon Anodes.

Metallic matrix materials have emerged as an ideal platform to hybridize with next-generation electrode materials such as silicon for practical applications in Li-ion batteries. However, these metallic species commonly exist in the form of isolated particles, failing to provide enough free space for silicon volume changes as well as continuous charge transport pathways. Herein, three-dimensional (3D) metallic frameworks with interconnected pore channels and conductive skeletons, have been synthesized from inorganic gel precursors as buffering/conducting matrices to boost lithium storage performance of silicon anodes. As a proof-of-concept demonstration, commercial Si particles are in situ immobilized within the Sn-Ni alloy framework via a facile gel-reduction route, and the rearrangement of Si particles during cycling increases the dispersity of Si in the Sn-Ni framework as well as their synergic effects toward lithium storage. The Si@Sn-Ni all-metallic framework manifests high structural integrity, 3D Li+/e- mixed conduction pathway, and synergic effects of interfacial bonding and concurrent reaction dynamics between active Si and Sn, enabling long-term cycle life (1205 mA h g-1 after 100 cycles at 0.5 A g-1) and superior rate capability (653 mA h g-1 at 10 A g-1).

Electrochemical Fabrication and Characterization of Alloy Anode Materials

Studies on secondary batteries with increased specific capacity and more stable charge-discharge performance have been actively conducted. Sn anode has a higher specific capacity than conventional carbon anode; however, the large volume change and cracking of the Sn anode occurs due to de-lithiation reaction during repetitive charge-discharge process. On the other hand, the Ni anode material is highly resistant to cracking during charge-discharge process. Therefore, in this study, the electrochemical formation of porous Sn-Ni alloy anode material is investigated using a polyurethane template of three-dimensional open-cell structure for lithium ion batteries having high specific capacity and improved structural reliability.

Tin–Nickel–Titania Composite Coatings

The effect of titania nanoparticles synthesized by direct oxidation of titanium powder on the cathodic polarization of the electrodeposition of Sn, Ni, and a Sn–Ni alloy in a fluoride–chloride electrolyte has been assessed using voltammetry. The morphology and phase composition of the coatings obtained have been studied by scanning electron microscopy and X-ray diffraction. The pH of the electrolyte has been shown to have a crucial effect on its stability and the quality of the coatings. The optimal pH of the electrolyte for the deposition process is 3.0 ± 0.1 and the optimal current density is 1.0 ± 0.1 A/dm2. The coprecipitation of nickel and tin into an alloy has been shown to be accompanied by a depolarization effect, due to the formation of NiSn2 and Ni3Sn2 intermetallic compounds. The addition of titanium dioxide shifts the alloy reduction process to more negative potentials. The addition of 2 g/L of titanium dioxide to an electrolyte leads to the incorporation of 0.7 wt % TiO2 into the composition of the coating.

Tailorable deposition of Sn[sbnd]Ni alloy from a pyrophosphate bath with an adjustable Sn:Ni molar ratio

Tailorable deposition was carried out by varying the Sn:Ni molar ratio of a pyrophosphate bath to adjust the deposition rate as well as the phase composition, morphology and corrosion resistance of the as-deposited SnNi alloy. The nickel content of the resultant SnNi alloy decreases gradually from 50 wt% to 28 wt% when the Sn:Ni molar ratio of electrolytes increases from 0.2 to 2.0 and remains reasonably constant at 31–37 wt% when the ratio is in the range of 0.6–1.8. Codeposition of a reasonable content of Ni with tin refines the crystal grains of the alloy and produces a compact coating. The phase composition of the SnNi alloy deposition changes along with the Sn:Ni molar ratio, and alloys with low nickel content are composed of Ni4Sn, Ni3Sn2 or Ni3Sn4 phases. A single-phase homogeneous intermetallic compound of Ni4Sn appears in alloys containing 31–37 wt% nickel. Compared to pure deposited Sn, the electrochemical measurements reveal that the SnNi alloys containing single-phase Ni4Sn have a smaller corrosion current density, smaller blunt current and larger electrochemical charge transfer resistance in 10% H2SO4 solution, indicating that the nearly equiatomic alloy SnNi exhibits excellent corrosion resistance in sulfuric acid solution.

The dual capacity of the Ni[sbnd]Sn alloy/MWCNT nanocomposite for sodium and hydrogen ions storage using porous Cu foam as a current collector

A nanostructured NiSn alloy/multi-walled carbon nanotube (MWCNT) composite was successfully synthesized for highly reversible sodium and hydrogen ions storage by using an electrochemical deposition process on porous Cu foam. The surface morphology of the resulting NiSn alloy/MWCNT nanocomposite was characterized using a field-emission scanning electron microscope, indicating the formation of sphere-like NiSn alloy nanoparticles with an average size of 190 nm. On the other hand, X-ray diffraction analysis, energy dispersive and Fourier transform infrared spectroscopies were employed to determine the crystalline structure, elemental surface and chemical composition of the nanocomposite electrode. The initial sodium discharge capacity of the electrode was maximized at ∼550 mAh g−1 under the current density of 1000 mA g−1, and a high hydrogen discharge capacity of 5200 mAh g−1 was obtained at 1100 mA g−1 after 20 cycles. A comprehensive comparison between the sodium and hydrogen ions capacities in this study and those of the literature for different materials and structures was also performed. Accordingly, the resulting nanocomposite electrode with dual capacity may offer promising applications in both sodium-ion battery and hydrogen storage.

Cu–Ni–Sn–Si alloys designed by cluster-plus-glue-atom model

Segregation in the solidification process and discontinuous precipitation during aging cause the service and processing performance of Cu–Ni–Sn alloys deteriorating severely. In this work, Si is added as a fourth element for the design of Cu80Ni15Sn5−xSix (x = 0, 0.625, 1.25, 1.875, 2.5) series alloys using cluster-plus-glue-atom model to solve these issues from the point of composition design. The results suggest that the introduction of Si leads to the disappearance of the lamellar structure formed in the as-cast alloys while also inhibiting discontinuous precipitation during aging. The solidus–liquidus temperature range is reduced with the addition of Si, and this strategy is most effective when the Si is in the solution state. With increasing Si content, the high-temperature conductive stability of the alloys is improved. Moreover, the hardness and conductivity of the Cu80Ni15Sn5 alloy designed by cluster-plus-glue-atom model are improved compared with those of C72900 (Cu78.96Ni16.65Sn4.39) commercial alloy, and the properties of Cu80Ni15Sn4.375Si0.625 alloy are basically equivalent to those of C72900 alloy. These findings indicate that alloys with excellent synthetic properties can be produced as long as the content and existential state of Si are reasonably controlled.

Preparation and solidification process of mono-sized Cu–Ni–Sn microspheres by pulsated orifice ejection method

Cu–Ni–Sn alloys are well known for their excellent properties, including excellent elasticity and high strength, which enable large potentials for applications in microelectronic industry and 3D printing for example. Preparation of the high quality spherical powders should meet the new requirements in these emerging fields. In this work, the mono-sized Cu-13Ni-17Sn (wt%) microspheres with controllable diameters ranging from 84.4 μm to 212.0 μm were prepared by pulsated orifice ejection method (POEM). Solidified Cu–Ni–Sn microspheres exhibit good sphericity and remarkably narrowed size distribution. The percentage of microspheres with sphericity of more than 0.9 is high up to 98.6%, and the average sphericity of microspheres is 0.989. The surface of Cu–Ni–Sn microspheres is smooth, and the interior contains no pores and impurities. Furthermore, the cooling rate of Cu-13Ni-17Sn microspheres was estimated in a Newton’s cooling model. With decreasing particle diameter, the cooling rate of Cu-13Ni-17Sn microspheres increases gradually. When the particle diameter is less than 84.4 μm, the cooling rate of microspheres exceeds 3.64 × 104 K s−1. With increasing particle size, the secondary dendrite arm spacing increases gradually owing to the decrease of the sphere cooling rate.

Chemoselective Hydrogenation of 4-Nitrostyrene to 4-Aminostyrene by Highly Efficient TiO2 Supported Ni3Sn2 Alloy Catalyst

Abstract Ni3Sn2 alloy catalysts supported on various metal oxides (TiO2, Al2O3, ZrO2, SnO2, and CeO2) were successfully prepared by simple hydrothermal method and then applied to the hydrogenation of 4-nitrostyrene under H2 3.0 MPa at 423 K. All the supported catalysts hydrogenated the nitro group more preferentially than the olefin group from the initial reaction stages, showing 100% chemoselectivities towards the desired 4-aminostyrene. This may be attributed to σ-interaction between the oxygen lone pairs in the nitro group and Sn atoms in Ni3Sn2 alloy. By prolonging the reaction times, the 4-aminostyrene yields increased and finally reached the maximum yields. Among the catalysts, Ni3Sn2/TiO2 alloy catalyst showed the highest catalytic activity with remarkably high chemoselectivity towards 4-aminostyrene. The conversion and chemoselectivity were 100% and 79%, respectively, at a reaction time of only 2.5 h. From the physical and chemical characterization of the supported catalysts, it was clear that the catalytic activity was correlated with H2 uptake. The application of the best catalyst for the hydrogenation of a wide variety of substituted nitroarenes resulted in the chemoselective formation of the corresponding aminoarenes.

Corrected accelerated service life test of electrodeposited NiSn alloys and Ni as cathodes for industrial alkaline water electrolysis

The ?corrected accelerated service life test for hydrogen evolution reaction? (CASLT-HER), designed for application of certain electrode materials as cathodes in the cell for alkaline water electrolysis in 30 % KOH at 80 ?C, was performed at electrodeposited NiSn alloy and Ni 40 mesh electrodes. The Ni 40 mesh was slightly etched, while the NiSn alloy coating was electrodeposited from the bath containing pyrophosphate, glycine, SnCl2 and NiCl2 onto Ni 40 mesh to the thickness of approximately 40 ?m. It is shown that the NiSn cathode possess from maximum 0.77 V to minimum 0.30 V better overpotential than the Ni 40 mesh electrode during the 5 years of their exploitation at the conditions of industrial alkaline water electrolysis. It is also shown that both electrodes should be held at j = ?0.3 A cm-2 for at least 5 h in order to establish stable overpotential response. The limiting overpotential values for applying cyclic voltammetry (CVs, to mimic ?polarity inversion?) should be determined in a separate experiment before the CASLT-HER and should be adjusted during the application of CVs.

Application of Sn-Ni Alloy as an Anode for Lithium-Ion Capacitors with Improved Volumetric Energy and Power Density

Lithium-ion capacitors (LIC) constructed by combining a supercapacitor-like cathode and battery-like anode are expected to bridge a gap between low power density from lithium-ion batteries (LIB) and low energy density from the supercapacitors. In this study, we synthesize the Sn-Ni alloy by electrodeposition in the aqueous solution as an anode for LIC. The lower volume expansion rate of Sn-86 than pure Sn anode can be confirmed by in-operando investigation using an optically transparent cell during the 1st charging process. This is attribute to the co-deposited Ni can act as a buffer matrix to restrain volume expansion. For the full-cell test, the pre-lithiation condition of Sn-Ni was investigated with different depth of discharge levels. As a result, a LIC consisting of activated carbon (AC) cathode and Sn-86 exhibits a good cyclability for 3000 cycles with a capacity retention of 80% and coulombic efficiency of 98% at 3000th cycle. The Sn-Ni//AC LIC shows improved volumetric energy and power density than graphite//AC LIC. This study presents a new possibility of Sn-Ni alloy as an anode for the improved electrochemical performance of LIC.

One-pot selective conversion of C5-furan into 1,4-pentanediol over bulk Ni–Sn alloy catalysts in an ethanol/H2O solvent mixture

The synergistic actions between an inexpensive bulk Ni–Sn(1.5) alloy, hydrogen gas, and an ethanol/H2O solvent mixture selectively assisted the one pot conversion of C5-furan compounds to 1,4-pentanediol with outstanding yields up to 92%.

NiSn nanoparticle-incorporated carbon nanofibers as efficient electrocatalysts for urea oxidation and working anodes in direct urea fuel cells

Synthesis of NiSn alloy nanoparticle-incorporated carbon nanofibers was performed by calcining electrospun mats composed of nickel acetate, tin chloride and poly(vinyl alcohol) under vacuum. The electrochemical measurements indicated that utilization of tin as a co-catalyst could strongly enhance the electrocatalytic activity if its content and calcination temperature were optimized. Typically, the nanofibers prepared from calcination of an electrospun solution containing 15 wt% SnCl2 at 700 °C have a current density almost 9-fold higher than that of pristine nickel-incorporated carbon nanofibers (77 and 9 mA/cm2, respectively) at 30 °C in a 1.0 M urea solution. Furthermore, the current density increases to 175 mA/cm2 at 55 °C for the urea oxidation reaction. Interestingly, the nanofibers prepared from a solution with 10 wt% of co-catalyst precursor show an onset potential of 175 mV (vs. Ag/AgCl) at 55 °C, making this proposed composite an adequate anode material for direct urea fuel cells. Optimization of the co-catalyst content to maximize the generated current density resulted in a Gaussian function peak at 15 wt%. However, studying the influence of the calcination temperature indicated that 850 °C was the optimum temperature because synthesizing the proposed nanofibers at 1000 °C led to a decrease in the graphite content, which dramatically decreased the catalyst activity. Overall, the study opens a new venue for the researchers to exploit tin as effective co-catalyst to enhance the electrocatalytic performance of the nickel-based nanostructures. Moreover, the proposed co-catalyst can be utilized with other functional electrocatalysts to improve their activity toward oxidation of different fuels.

Influence of Sn content on the electrocatalytic activity of NiSn alloy nanoparticles-incorporated carbon nanofibers toward methanol oxidation

Improvement of the electrocatalytic activity of nickel toward methanol oxidation can be conducted by exploiting the synergetic influence of a co-catalyst and/or utilizing a proper support. In this study, utilizing tin as a co-catalyst and supporting on carbon nanofibers are proposed to enhance methanol oxidation in the alkaline media. Typically, NiSn nanoparticles alloy-incorporated carbon nanofibers could be prepared by calcination of electrospun nanofibers composed of poly (vinyl alcohol), nickel acetate tetrahydrate and tin chloride under argon atmosphere at a high temperature. The influence of the co-catalyst content and the calcination temperature on the morphology, composition and electrocatalytic activity of the proposed nanofibers was investigated. Smooth electrospun nanofibers can be prepared regardless the tin chloride content up to 35 wt%, and the calcination process did not distinctly affect the nanofibrous morphology. Mostly, Ni3Sn and Ni3Sn2 nanoparticles-incorporated amorphous carbon nanofibers were obtained at all the utilized calcination temperatures (700, 850 and 1000 °C) and examined SnCl2 contents. However, at 10 wt% SnCl2 content and 850 °C calcination temperature, single metallic compound (Ni3Sn2)-incorporated carbon nanofibers were synthesized. Electrochemical measurements indicated that the electrocatalytic activity depends strongly on the tin content as well as the calcination temperature. The nanofibers obtained from electrospun solution containing 10 wt% SnCl2 and calcined at 850 °C showed very good performance compared to the other formulations. Typically, the corresponding onset potential of the methanol oxidation reaction using these nanofibers catalyst is 315 mV (vs. Ag/AgCl) while it was 405 mV for the nanofibers obtained from electrospun solution containing 0, 5, 15, 25 and 35 wt% SnCl2. Moreover, the best nanofibers reveal the highest current density. Kinetic study indicated that the corresponding activation energy is 15.6 kJ/mol.

Chemoselective Hydrogenation of Unsaturated Nitro Compounds to Unsaturated Amines by Ni-Sn Alloy Catalysts

Ni-Sn alloy catalysts were prepared and applied to the hydrogenation of 4-nitrostyrene at 383–423 K using H2 gas as the hydrogen donor. Ni3Sn2 alloy showed a significantly high conversion and selec...

Selective Hydrogenation of Dodecanoic Acid to Dodecane-1-ol Catalyzed by Supported Bimetallic Ni-Sn Alloy

Selective hydrogenation of dodecanoic acid over supported bimetallic Ni-Sn alloy catalysts into dodecane-1-ol is demonstrated. Bimetallic nickel-tin supported on titanium oxide (Ni-Sn(1.5)/TiO2) and gamma-alumina (Ni-Sn(1.5)/g-Al2O3); 1.5 = Ni/Sn molar ratio) were synthesized via hydrothermal method in a sealed-Teflon autoclave reactor at 150 oC for 24 h, then followed by reducing with hydrogen gas at 400 oC for 1.5 h. The synthesized catalysts were characterized by means of XRD, IC-AES, N2-adsorption (BET method), H2-chemisorption, and NH3-TPD. Bimetallic Ni-Sn(1.5)/TiO2 catalyst was found to be effective for hydrogenation of dodecanoic acid (>99 % conversion) to dodecane-1-ol (93% yield) at 160 oC, 30 bar H2, and 20 h and the highest dodecane-1-ol (97 % yield) was obtained at initial pressure of H2, 50 bar. An increase of reaction temperature slightly enhanced the degree of hydrodeoxygenation of dodecanoic acid to produce dodecane over both Ni-Sn(1.5)/TiO2 and Ni-Sn(1.5)/g-Al2O3 catalysts.

First-principles study of the (CuxNi1 − x)3Sn precipitations with different structures in Cu–Ni–Sn alloys**Project supported by the National Key Research and Development Program of China (Grant No. 2016YFB0301402), the Project of Innovation-Driven Plan in Central South University, and the State Key Laboratory of Powder Metallurgy, Central South University, Changsha, China.

The structural parameters, the formation energies, and the elastic and thermodynamic properties of the (CuxNi1 − x)3Sn phase with different structures are studied by the virtual crystal approximation (VCA) and super-cell (SC) methods. The lattice constants, formation energies, and elastic constants obtained by SC and VCA are generally consistent with each other. It can be inferred that the VCA method is suitable for (CuxNi1 − x)3Sn ordered phase calculation. The calculated results show that the equilibrium structures of Cu3Sn and Ni3Sn are D0a and D019 respectively. (CuxNi1 − x)3Sn_D03 with various components are the metastable phase at temperature of 0 K, just as D022 and L12. With the temperature increase, the free energy of the D03 is lower than those of D022 and L12, and D022 and L12 eventually turn into D03 in the aging process. The (CuxNi1 − x)3Sn_D022 is first precipitated in a solid solution because its structure and cell volume are most similar to those of a solid solution matrix. The L12 and the D022 possess better mechanical stability than the D03. Also, they may play a more important role in the strengthening of Cu–Ni–Sn alloys. This study is valuable for further research on Cu–Ni–Sn alloys.

Novel three dimensional hierarchical porous Sn-Ni alloys as anode for lithium ion batteries with long cycle life by pulse electrodeposition

In this paper, novel three dimensional hierarchical porous Sn-Ni (3D-HP Sn-Ni) alloys were investigated as a promising anode for high-performance Li ion batteries (LIBs), which was fabricated by pulse electrodeposition of mesoporous Sn-Ni alloy made of ultrafine nanoparticles on the 3D nanoporous copper substrate from chemical dealloying of as-cast Al55Cu45 (at.%) alloy slices in the HCl solution. The results show that the as-obtained 3D-HP Sn-Ni alloys are typically characteristic of open, bicontinuous, interpenetrating bimodal pore size distribution comprising large-sized (hundreds of nm) ligament-channel network architecture with highly porous channel walls (several nm). Compared to the two dimensional nanoporous Sn-Ni (2D-NP Sn-Ni) thin films, the 3D-HP Sn-Ni alloys as anode for LIBs show superior cycling stability with reversible specific capacity of 0.25 mAh cm−2 and coulombic efficiency of more than 95% up to 200 cycles. Moreover, the reversible capacity as high as 0.22 mAh cm−2 can be achieved even after a series of high-rate charge–discharge cyclings. The satisfactory electrochemical properties can be mainly ascribed to the unique 3D hierarchical porous structure, large contact surface area between active material and electrolyte, as well as good buffer effect of inactive component, which is greatly beneficial to alleviate the huge volume variation, enhance the loading mass of active material, shorten the Li+ migration distance and improve the electron conductivity. We believe that this present work can provide a promising anode candidate towards practical application of high-performance LIBs.

Effect of Sn addition on improving the stability of Ni-Ce0.8Sm0.2O1.9 anode material for solid oxide fuel cells fed with dry CH4

Sn-NiO-Ce0.8Sm0.2O1.9 (SDC) is synthesized as an anode material for solid oxide fuel cells with H2 and dry methane as fuels. Sn-Ni alloy is formed after reduction. The performances of anode-supported single cells with a configuration of Sn-Ni-SDC|SDC|Ba0.5Sr0.5Co0.8Fe0.2O3-δ are investigated in the range of 600–700 °C. With increasing Sn content of the anode, the performances of the cells fed with H2 and dry methane both decrease slightly, indicating a reduced anodic catalytic activity. However, the stability of the cell with dry methane as fuel improves remarkably with the addition of Sn due to the suppression of carbon deposition on the anode.

NiSn bimetallic nanoparticles as stable electrocatalysts for methanol oxidation reaction

Nickel is an excellent alternative catalyst to high cost Pt and Pt-group metals as anode material in direct methanol fuel cells. However, nickel presents a relatively low stability under operation conditions, even in alkaline media. In this work, a synthetic route to produce bimetallic NiSn nanoparticles (NPs) with tuned composition is presented. Through co-reduction of the two metals in the presence of appropriate surfactants, 3–5 nm NiSn NPs with tuned Ni/Sn ratios were produced. Such NPs were subsequently supported on carbon black and tested for methanol electro-oxidation in alkaline media. Among the different stoichiometries tested, the most Ni-rich alloy exhibited the highest electrocatalytic activity, with mass current density of 820 mA mg−1 at 0.70 V (vs. Hg/HgO). While this activity was comparable to that of pure nickel NPs, NiSn alloys showed highly improved stabilities over periods of 10,000 s at 0.70 V. We hypothesize this experimental fact to be associated to the collaborative oxidation of the byproducts of methanol which poison the Ni surface or to the prevention of the tight adsorption of these species on the Ni surface by modifying its surface chemistry or electronic density of states.