Ni-coated Carbon Research Articles

Vermiform Ni@CNT derived from one-pot calcination of Ni-MOF precursor for improving hydrogen storage of MgH2

The Ni-coated carbon nanotubes (Ni@CNT) composite was synthesized by the facile “filtration + calcination” of Ni-based metal−organic framework (MOF) precursor and the obtained composite was used as a catalyst for MgH2. MgH2 was mixed evenly with different amounts of Ni@CNT (2.5, 5.0 and 7.5, wt.%) through ball milling. The MgH2−5wt.%Ni@CNT can absorb 5.2 wt.% H2 at 423 K in 200 s and release about 3.75 wt.% H2 at 573 K in 1000 s. And its dehydrogenation and rehydrogenation activation energies are reduced to 87.63 and 45.28 kJ/mol (H2). The in-situ generated Mg2Ni/Mg2NiH4 exhibits a good catalytic effect due to the provided more diffusion channels that can be used as “hydrogen pump”. And the presence of carbon nanotubes improves the properties of MgH2 to some extent.

Synthesis and application of NiLa-layered double hydroxides on nickel-coated carbon nanotubes with Co-ZIF-67 composite in supercapacitors

Owing to the global climate emergency, there is considerable interest in new energy generation and storage solutions. Supercapacitors have many desirable properties of particular interest for energy storage. However, they have low energy densities, which must be improved. Materials based on zeolite imidazole skeletons (ZIFs) have uniform pores, large specific surface areas, and simple structures. Moreover, Co-ZIF-67 has high electrical conductivity, which makes it a promising candidate for energy storage applications. In this study, a Co-ZIF-67 precursor with a regular cubic structure is synthesized. This precursor is combined with Ni-coated carbon nanotubes (Ni-CNTs) and NiLa-layered double hydroxides (NiLa-LDHs). Thus, by controlling the hydrothermal reaction time, an electrode material with a nanosheet structure is applied to the CNTs. Electrochemical analysis shows that the resulting Co-ZIF-67/Ni-CNT@NiLa-LDH composite has a specific capacitance of 1710 F g−1 at a current density of 1 A g−1. The composite is combined with activated carbon (AC) to produce a Co-ZIF-67/Ni-CNT@NiLa-LDH//AC asymmetric supercapacitor, which exhibits outstanding capacitive performance (150.1 F g−1 at a current density of 1 A g−1), a wide operating voltage window (1.7 V), and outstanding stability.

Strong composite SnAgCu solder joints with internal aligned carbon fibers by magnetic field

Lightweight carbon fibers with high mechanical performance are referred to as an ideal reinforcement for an extensive variety of composite materials. However, the addition of carbon fibers into electronic interconnection solders is extremely limited so that the expected reinforcement in the mechanical properties of the composite solder joints has not been completely realized. Here, we used magnetic fields to align Ni-coated carbon fibers in the Sn-3.0Ag-0.5Cu solder vertically with the Cu substrate and prepared the oriented composite solder joints. We achieved a further improvement in the shear performance of composite solder joints (∼58 MPa) with a small addition of Ni-coated carbon fibers (0.5 wt%), which is 25% higher than that of pristine joints. It is found that these vertically oriented carbon fibers changed the propagation path of shear cracks and thus increased the shear resistance. Ni-coated carbon fibers also promoted nucleation of interfacial Cu6Sn5 in the solder joints during reflow, but prevented the formation of brittle Cu3Sn phase during isothermal aging, thus ensuring the high shear strength of composite solder joints after isothermal aging. This success provides a new pathway to fabricate a strong composite solder joint with a limited addition of reinforcements by aligning their orientation.

Enhanced Thermal Stability and Conductivity of FeF3 Using Ni-Coated Carbon Composites: Application as High-Temperature Cathodes in Thermal Batteries.

Cathode active materials and conductive additives for thermal batteries operating at high temperatures have attracted research interest, with a particular focus on compounds offering high thermal stability. Recently, FeF3 has been proposed as a candidate for high-voltage cathode materials; however, its commercialization is hindered by its low conductivity. In this study, conductive additives, such as Ni-coated carbon composites (multi-walled carbon nanotubes (MWCNTs) and carbon black (CB)), were utilized to enhance the thermal stability and conductivity of FeF3. The incorporation of metal-carbon conductive additives in the FeF3 composite increased the thermal stability by more than 10 wt.% and ensured high capacity upon conductivity enhancement. The FeF3@Ni/MWCB 15 wt.% composite containing 30 wt.% Ni exhibited a discharge capacity of ∼86% of the theoretical capacity of 712 mAh/g. The use of Ni-coated carbon-based conductive additives will allow the application of FeF3 as an effective high-temperature cathode material for thermal batteries.

Effect of Cu/Ni coating on the interface and mechanical properties of Cf/2024Al composites

To improve the interface between the carbon fiber and aluminum matrix, the carbon fibers were modified with Cu coating and Ni coating by using electroless plating. The Cu-coated and Ni-coated carbon fibers reinforced 2024Al matrix composites (denoted as Cf(Cu)/2024Al and Cf(Ni)/2024Al) were prepared by spark plasm sintering at 480 °C for 10 min under a uniaxial pressure of 30 MPa. Microstructure observations show that the interfacial reaction between carbon fibers and aluminum matrix can be efficiently obstructed by coating the carbon fiber with Ni, while it still proceeds as the carbon fibers were coated with Cu. The nanohardness of the interface for Cf(Cu)/2024Al composite is 2.68 GPa, which is 16.5% higher compared to Cf(Ni)/2024Al composite (2.30 GPa) due to the produced hard Al4C3 at the interface. The tensile strength and strain of Cf(Ni)/2024Al composites are 284 MPa and 6.4%, which are increased by 4.4% and 28.0% respectively compared to Cf(Cu)/2024Al composites. The Ni coating plated on the carbon fiber results in moderate interfacial bonding and avoids damage to the carbon fiber, which is efficient in deflecting cracks and increasing the crack propagation path, as well as consuming more fracture energy.

Fabrication of Textured Ni-Coated Carbon Tubes for a Flexible Strain Sensor: Effect of the Device Elastic Modulus on Sensor Performance.

The exploration of flexible resistive sensors with excellent performance remains a challenge. In this paper, a nickel-coated carbon tube with a textured structure was prepared as a conductive sensitive material and inserted into the poly(dimethylsiloxane) (PDMS) polymer; interestingly, the sensor performance was controlled by the elastic modulus of the matrix resin. The results show that Pd2+ may be adsorbed by the active groups on the surface of a plant fiber as a catalytic center for the reduction of Ni2+. After 300 °C annealing, the inner plant fiber would be carbonized and attached to the outside of the nickel tube; to be precise, the textured Ni-encapsulated C tube was fabricated successfully. It is worth noting that the C tube serves as a layer of support for the external Ni coating, providing sufficient mechanical strength. In addition, resistance sensors with different properties were prepared by controlling the elasticity modulus of the PDMS polymer by introducing different contents of curing agents. The limit uniaxial tensile strain was enhanced from 42 to 49% and sensitivity reduced from 0.2 to 2.0% with the elasticity modulus of the matrix resin increasing from 0.32 to 2.2 MPa. As expected, the sensor is obviously appropriate for the detection of elbow joints, human speaking, and human joints with the reduction of the elasticity modulus of the matrix resin. To be precise, the optimal elastic modulus of the sensor matrix resin would facilitate the improvement of its sensitivity to monitor different human behaviors.

Wear behavior of Ni-coated carbon fiber and ZrC particles reinforced 2024Al matrix composites

The dry sliding wear behavior of ZrC particles and carbon fiber reinforced 2024Al matrix composite rubbed against AISI52100 bearing steel was investigated at different loads and sliding velocities. The wear rate of the composite increased with increasing load, while an opposite trend was recorded as the velocity increased. With increasing load and speed, the wear mechanism changed from major abrasion wear, slight adhesive wear, and oxidative wear to dominant oxidative wear, secondary abrasion, and adhesive wear. The improved wear resistance of the composite over that of the 2024Al alloy is attributed to the steady mechanically mixed layer supported by the harder and stronger composites, as well as the self-lubricating carbon fibers.

Magnetic properties of Ni-coated fibers in a polymer matrix for electro-magnetic interference shielding applications

Electromagnetic interference shielding composite materials can be designed with properties that are tailored for specific applications. We have explored the magnetic properties of Ni-coated carbon fibers embedded in a polymer matrix through an extrusion process. This method can produce large, pliable flat sheets, which can be easily bent and shaped. Microscopy imaging shows that the extrusion process preferentially orders most of the fibers with their long axis along the extrusion direction. The measured samples reached 90% of the saturation magnetization value at a field of approximately 800 Oe along the extrusion direction, much lower than needed for other directions (in-plane perpendicular to the extrusion or perpendicular to the foil surface). A field on the order of 6 kOe must be applied to obtain the full saturation of the magnetization in all three directions. The absorption characteristics were measured, with zero external applied field to determine the shielding effectiveness of the composite materials for multiple orientations with respect to the TE10 mode of an S-band waveguide. The nickel-coated carbon fiber composite materials exhibit dramatic orientation-dependent shielding effectiveness. The most effective orientation has shielding effectiveness of up to 45 dB at 4.5 GHz, which is comparable to multi-walled carbon nanotube composites with similar volumetric filling fractions.

Effect of NiO–NiCr2O4 nano-oxides on the microstructural, mechanical and corrosion properties of Ni-coated carbon steel

Effect of NiO–NiCr2O4 nano-oxides on the microstructural, mechanical and corrosion properties of Ni-coated carbon steel

Ferromagnetic resonance of hollow micron-sized magnetic cylinders

We have explored dynamic magnetic properties of micron-sized Ni-coated carbon fibers embedded in a polymer matrix for electromagnetic interference shielding applications. These hollow magnetic cylinders exhibit unusual dynamic magnetic properties, which were measured with a broad-band ferromagnetic resonance system (FMR). We observe three families of FMR modes, which are connected to different physical locations within the cylinder. We develop a simple analytic model to explain these results and corroborate resonant mode profiles with micromagnetic simulations. We find excellent agreement between experimental results and theoretical models. Our work indicates that global demagnetizing factors are not appropriate for understanding the spin motions in these hollow cylinders. The FMR absorption observed in these hallow cylinders is very different from those observed in nanowires or solid cylinders. The field-swept envelope of all the observed FMR resonances is very broad, approximately μ0H = 1 T, with a linewidth of individual modes around μ0ΔH = 250 mT. This can be important for electromagnetic shielding applications.

The aging behavior of Ni-coated carbon fibers and ZrC particles reinforced 2024Al matrix composites

In this paper, the aging behavior of Cf(Ni)-ZrC/2024Al composites with a quasi-network structure was studied carefully. The microstructure observation exhibits that the ZrC particles, carbon fibers, and Al matrix form a good interface bonding. The interfacial phase between the carbon fiber and Al matrix exhibits good thermostability during solution and aging treatment. With the addition of carbon fibers and ZrC particles, the composites only take 8 h to reach peak-aged condition while in monolithic 2024Al alloy, it needs 12 h. The peak-aged hardness of the composites is 136.4 HV, having 15.2% increments than 2024Al (118.4 HV). The yield, tensile strength, and strain of the peak-aged composites are 350.5 MPa, 536.4 MPa, and 14.8% respectively, which are improved by 56.5%, 45.8%, and 52.6% compared with 2024Al. The yield and tensile strength of composites are increased with time going by until they reach a peak aging state, agreeing well with that of hardness. The TEM observations of precipitated phases demonstrate the size and number of Al 2 Cu and Al 2 CuMg present a similar variation tendency. The improved tensile property of the composites is mainly due to pulled-out carbon fibers, quasi-network structure, outstanding interface bond, and precipitate strengthening. • The Cf(Ni)-ZrC/2024Al composites only take 8 h to reach to peak-aged condition, while the 2024Al needs 12 h. • The yield, tensile strength and strain of the composites are significantly improved compared with the 2024Al. • The improved strength is due to pulled-out carbon fiber, quasi-network structure, good interface bond and fine precipitate.

Effect of Ni-Coated Carbon Nanotubes Additions on the Eutectic Sn-0.7Cu Lead-Free Composite Solder

Sn-0.7Cu-based (all in wt.% unless specified otherwise) composite solders functionalized with Ni-coated carbon nanotubes (CNTs) with various weight proportions ranging from 0.01 to 0.2 wt.% were successfully produced. The Ni-coated CNTs were synthesized with discontinuous nickel coating by an improved electroless nickel plating technique. The microstructural, melting and wetting properties of Sn-0.7Cu-based composite solders were evaluated as a function of different amounts of Ni-coated CNTs addition. Compared to Sn-0.7Cu, it was observed that the microstructure of the composite solder added to the Ni-coated CNTs was still composed of the intermetallic compound Cu6Sn5 in a β-Sn matrix, but the micromorphology changed greatly. When 0.05 wt.% Ni-coated CNTs were added, the rod-shaped Cu6Sn5 particles disappeared, and all appeared in a form of dot-shaped Cu6Sn5 particles. DSC results showed only a slight decrease in the melting behavior of the composite solder. Experimental results unveiled that the addition of Ni-coated CNTs to Sn-0.7Cu solder could improve the wettability. With the addition of 0.05 wt.% Ni-coated CNTs, the wetting angle decreased by 13.35%, and an optimum wetting angle of 25.44° was achieved.

Impact of Ni-coated carbon fiber on the interfacial (Cu,Ni)6Sn5 growth of Sn-3.5Ag composite solder on Cu substrate during reflow and isothermal aging

In this work, a novel composite solder was fabricated by mechanically incorporating Ni-coated carbon fiber (Ni-CF) into the Sn-3.5Ag solder paste in an effort to improve the overall service capability, where the intermetallic compound (IMC) formation and growth is a fundamental issue for consideration. General findings indicated that the addition of Ni-CF did not significantly impact the processing properties of the base alloy, such as melting temperature and wettability, when the reinforcement fraction was less than 2 wt%. Isothermal aging tests were carried out to study the formation and growth of interfacial IMC layers between the composite solder and Cu substrate. The addition of Ni-CF into Sn-3.5Ag solder could effectively promote the formation of interfacial (Cu, Ni)6Sn5 phase during reflow but retard its growth in the solid-state aging. The addition of 1 wt% Ni-CF was believed to be more effective to restrict and reduce the subsequent growth rate of the IMCs during solid-state aging due to the initial formation of a thicker (Cu, Ni)6Sn5 layer after reflow.

Effect of Ni-coated carbon nanotubes addition on the wettability, microhardness, and shear strength of Sn-3.0Ag-0.5Cu/Cu lead-free solder joints

Effect of Ni-coated carbon nanotubes addition on the wettability, microhardness, and shear strength of Sn-3.0Ag-0.5Cu/Cu lead-free solder joints

A facile method combined with electroless nickel plating and carbonization to fabricate textured Ni-coated carbon tube for flexible strain sensor

High-sensitive textile sensor acts the key component of electronic wearable products. It is a challenge to low-cost fabricate flexible sensors that possess excellent response reliability. In this regard, we employ a facile method combined with electroless nickel plating and carbonization to fabricate textured Ni-coated carbon tube (Te-CNiT) electrode, used as sensitive material for resistive sensor. Results showed that active group on the cotton surface would facilitate the adsorption of Pd2+. The generated Pd particle served as catalytic center to catalyze the electroless nickel plating by means of core-sheath micronfiber yarn with weave structure. Moreover, the “core” layer is transited from plant fibre to amorphous carbon which attached to the inside of Ni tube after annealing at 300 °C for 1 h, as a result, Te-CNiT electrode was fabricated. Interestingly, the change relationship between the relative resistance and strain present a quadratic equation of one variable, more specifically, the dependent variable varies obviously with the independent variable due to the established of extra conductor resistance and contact resistance in the Te-CNiT under the action of strain. As expected, the developed sensor exhibited ultrahigh sensitivity with a detection limit of 0.3% and gauge factor of 359. It can be integrated with the human body to detect multiple tiny signals, such as body movement, vocal cord vibration and facial expression with low response/recovery time (0.06 s/0.04 s) and excellent stability (9000 cycles).

Microstructure and shear property of Ni-coated carbon nanotubes reinforced InSn-50Ag composite solder joints prepared by transient liquid phase bonding

InSn-50Ag composite solder joints doping Ni-coated carbon nanotubes (Ni-CNTs) were fabricated by transient liquid phase (TLP) bonding, and then the effect of Ni-CNTs contents (x = 0, 0.01, 0.03, 0.05, 0.07, 0.1 wt%) on the microstructure and shear property of the composite solder joints was examined. The results showed that the microstructure of Cu/InSn-50Ag-x(Ni-CNTs)/Cu composite solder joints consisted of the interfacial region bamboo-type Cu3(In, Sn), solder center region Ag3In, Ni3Sn4, Ag particles and Ni-CNTs. The appropriate amounts of Ni-CNTs (about 0.07 wt%) are conducive to form a compact composite solder joint and restrain the growth of interfacial Cu3(In, Sn) IMC layer, and the morphologies of IMC layer are determined by Ni-CNTs suppressing atom diffusion and IMC grain orientation. The shear strength of composite solder joints relates to Ni-CNTs content, and the maximum shear strength reaches 42 MPa of Cu/InSn-50Ag-0.07(Ni-CNTs)/Cu. It is regulated by uniform distribution of Ni-CNTs, refined Ag3In grains and interface IMC layer with near-continuous voids. The fracture of the composite solder joints doped Ni-CNTs occurred near to the boundary between the interfacial IMC layer and solder center region, the fracture mechanism is ductile fracture.

Broadband and tunable high-performance microwave absorption properties by Ni-coated carbon fibers

Composites of carbon fibers (CFs) and magnetic metals have concerned attention for tunable microwave absorption materials (MAMs). In this work, magnetic nickel (Ni) particles were coated on the CFs surface by an electroplating technique. Different morphology of Ni-coated CFs was established by setting the plating time. The microstructure, electric and magnetic properties, complex permittivity and permeability, and reflection loss (RL) of the Ni-coated CFs were specified as a function of the surface morphology of composites. SEM and EDX results displayed that Ni particles are uniformly deposited on the surface of CFs. Moreover, the Ni-coated CFs with different coating morphologies exhibit different microstructure. The creation of a magnetic Ni layer onto CFs improved composite properties, not only raising the saturation magnetization (17–46 emu/g) but also enhancing electrical conductivity (361–594 S/cm). The electromagnetic parameters and RL values of the Ni-coated CFs were investigated over the 2.0–18.0 GHz frequencies. The minimum RL could reach up to −64.8 dB at 14.9 GHz with 2.0 mm matching thickness and high effective bandwidth of 2.2–18.0 GHz. It has been displayed that the properties of Ni-coated CFs can be effectively controlled by changing the morphology of the Ni layer, which provides a novel route to fabricate Ni-coated CFs with tunable and broadband microwave absorption properties.

Interficial Bonding within Cu-based Composites Reinforced with TiC- or Ni-coated Carbon Fiber

Interficial Bonding within Cu-based Composites Reinforced with TiC- or Ni-coated Carbon Fiber

Improved strength, toughness and electrical properties of rigid polyurethane composites reinforced with Ni-coated carbon fibers

Improved strength, toughness and electrical properties of rigid polyurethane composites reinforced with Ni-coated carbon fibers

Stabilized Interfacial Intermetallic Compound Evolution in Ni-Coated Carbon Fiber Reinforced Sn-3.5Ag Composite Solder Joint

Stabilized Interfacial Intermetallic Compound Evolution in Ni-Coated Carbon Fiber Reinforced Sn-3.5Ag Composite Solder Joint