High Conductivity Research Articles

Random Vibration Fatigue Life Prediction of Nano-Silver Solder Joint

Nano-silver is a very potential electronic interconnection material. It’s excellent physical and chemical properties, high thermal conductivity and good electrical conductivity make it very suitable for high power electronic devices. In practical engineering, 20% of the failure of electronic products is caused by vibration load, so it is necessary to study the vibration reliability of interconnected materials. In this paper, the modal and random vibration finite element analysis of nano-silver solder joints were analyzed with workbench software. Predicting random vibration fatigue life of nano-silver solder joint by Coffin-Manson high cycle fatigue empirical formula, Miner’s linear cumulative damage theory and Steinberg model. The random vibration fatigue life of the nanosilver solder joint is 8342 h. It is found that the vibration reliability of nano-silver is inferior to Sn3.0Ag0.5Cu and Sn63Pb37 and the diameter of solder joints and PCB thickness are proportional to the vibration fatigue life, and the PCB thickness has a greater effect on the vibration life than the solder joint diameter. Solder joint height and pad thickness are inversely proportional to vibration fatigue life, and pad thickness has little effect on vibration fatigue life.

Poly (biphenyl-isatin-piperidine) anion exchange membrane with high hydroxide conductivity based on hydrophilic alkoxy spacer chains

Poly (biphenyl-isatin-piperidine) anion exchange membrane with high hydroxide conductivity based on hydrophilic alkoxy spacer chains

Anion trapping-coupling strategy driven asymmetric nonflammable gel electrolyte for high performance sodium batteries

Gel polymer electrolytes, promising electrolyte candidates for advanced sodium metal batteries (SMBs), suffer from the great challenges of combustion risk and inferior interfacial stability caused by poor mechanical properties and low Na+ selectivity. Herein, we proposed a rational anion trapping-coupling strategy to build a mechanically robust asymmetric nonflammable composite gel electrolyte (AS-NFCGE) by introducing in-situ coupled boron nitride nanosheets (BNNs) on glass fiber matrix embedded with synchronous polymerized flame-retardant polymer. Theoretical calculations, finite-element simulations, and experimental tests prove that the high coupling BNNs with anion trapping effect constructed asymmetric structure can significantly accelerate selective Na+ migration kinetics, enhance mechanical properties of AS-NFCGE and endow a similar single-ion conducting behavior to homogenize ion-distribution at the anode side, thus improving interfacial stability and suppressing dendrite growth to achieve ultra-stable SMBs. Specifically, the AS-NFGE delivers high ionic conductivity and Na+ transference number (0.73) together with excellent flam-retardant. Consequently, the dendrite-free Na/Na symmetric cell exhibits considerable cycling life for over 3000 h at 0.1 mA cm−2 with low overvoltage. Applications of the AS-NFCGE in SMBs further demonstrate the excellent electrochemical performances, and no thermal runaway and no electrolyte leakage occur for pouch cells using AS-NFCGE. This strategy provides new insight into the development of safe and high-energy SMBs and the beyond.

Modelling of the microstructure and thermal conductivity of SiC bonded diamond materials

Materials with high thermal conductivity are required in a wide range of thermal management applications. Silicon carbide (SiC) bonded diamond materials, which can be produced without pressure, are a possible candidate for such applications. They exhibit thermal conductivities > 650 W/(m·K) depending on the diamond content, diamond grain size and residual silicon content. It is difficult to experimentally determine the influence of these factors on the thermal conductivity separately, as changing one of these parameters affects the other parameters. Therefore, a method for generating digital microstructures of SiC bonded diamond materials was developed and the thermal conductivity was calculated as a function of the grain size These data were compared with real structures.

Achieving enhanced thermal conductivity and mechanical properties in Mg-Zn-Gd-Zr alloys via regulation microstructure characteristics

It is well known that the microstructure of metallic materials determines the mechanical properties. However, the effect of microstructure on thermal conductivity lacks an accurate quantitative description of this relationship. In this work, the mechanism of variation in mechanical and thermal conductivities with microstructure was revealed by the characterization of cast, heat-treated, and extruded Mg-xZn-yGd-0.6Zr (wt%) alloys: ZV66, ZV62, and ZV26. The contributions of solution atoms, second phases, grain size, and dislocations to the yield strength and thermal conductivity were quantitatively calculated, and their effects on the plasticity and work-hardening behavior were qualitatively analyzed. The results show that hot extrusion promotes the precipitation of nanoprecipitates, such as MgZn2, Mg4Zn7, and Mg5Gd, resulting in the reduction of Zn and Gd solute atoms and the introduction of high-density dislocations and grain boundaries. The extruded ZV66 alloy exhibits excellent mechanical properties and thermal conductivity (a tensile yield strength of 232 MPa, an elongation of 22 %, and a thermal conductivity of 127.6 W/(m·k)); these values are better than those reported for similar products. The achievement of high strength and thermal conductivity is attributed to the precipitation of solute atoms to improve thermal conductivity in addition to grain boundary strengthening and work-hardening strengthening to improve strength. These findings provide new insights into achieving excellent strength–thermal conductivity property amalgamations in magnesium alloys by tailoring their microstructure.

Design and Implement a BTMS using Phase Change Material - A Review

Abstract: This paper presents a comprehensive review of the design and implementation of Battery Thermal Management Systems (BTMS) utilizing Phase Change Materials (PCM). The thermal management of batteries is crucial for ensuring optimal performance, safety, and longevity, particularly in electric vehicles and renewable energy storage applications. Phase change materials offer unique advantages for thermal management, including high latent heat storage capacity, thermal conductivity, and temperature regulation capabilities. This review discusses the fundamentals of PCM-based BTMS design, including PCM selection, integration methods, and system optimization techniques. Additionally, recent advancements, challenges, and future directions in PCM-based BTMS are explored, providing valuable insights for researchers, engineers, and industry practitioners in the field of energy storage systems.

Characteristics of Metal Additive Manufacturing for the Fabrication of Inconel 625-pure Copper Bimetallic Structure with High Heat Resistant and Heat Conduction

Characteristics of Metal Additive Manufacturing for the Fabrication of Inconel 625-pure Copper Bimetallic Structure with High Heat Resistant and Heat Conduction

Graphene-based synthetic peptide electrochemical sensor for colorectal cancer diagnosis

This work reports the development of an electrochemical sensor using graphene-peptide conjugates for detecting colorectal cancer (CRC) biomarker leucine-rich alpha-2 glycoprotein-1 (LRG1). To enable LRG1 quantification, we rationally designed peptides with dual graphene anchoring motifs for optimal orientation and binding activity when immobilized on a reduced graphene oxide (rGO) electrochemical transducer surface. The graphene nanomaterial provides several advantages such as high conductivity, large surface area, and excellent stability that can enhance the sensor's analytical performance metrics. Furthermore, the synthetic peptides offer benefits like smaller size, specificity, ease of modification and cost-effective production compared to traditional antibody receptors. Under optimized conditions, the peptide sensor exhibited high sensitivity of 22.3 μA/(ng/mL.cm2), low limit of detection (75 pg/mL LRG1 in serum), accuracy of 101.1 % spiked recovery, and precision within 6 % RSD. Testing with colonoscopy-classified patient serum specimens discriminated normal, precancerous adenomatous polyps and malignant carcinoma stages based on LRG1 overexpression. A 24 % elevation for adenomas and 103 % higher levels in CRC were observed. Validation with spiked plasma samples indicated 97–104 % recovery and <7 % RSD, proving accurate detection capability. Comparison to antibody-based sensors showed superior linear range, sensitivity, reproducibility, and faster assay time. This demonstrates the promise of computational peptide designing combined with advanced nanomaterials for electrochemical detection of CRC progression through serum protein biomarkers.

Azine Based Oligoesteric Chemosensors for Cu2+ Ion Detection: Synthesis, Structural Characterization, and Theoretical Investigations.

Synthesized monomer and its three oligoesters were characterized by techniques such as 1H, 13C{1H}, IR, UV, GPC and applied to chemosensor applications. A series of metal ions was studied with fluorophores to evaluate the sensitivity towards Cu2+ ion. The fluorophores results exhibit the selective and sensitive "Turn off" fluorescence response with Cu2+ ion in DMF/H2O (1:1, pH: 7.4, fluorophore: 5µM) solution. Binding stoichiometry and binding constant of fluorophores were calculated using Stern-Volmer equation and Benesi-Hildebrand plots, respectively. Structure of fluorophores were studied using DFT, B3LYP/6-311 + + G(d,p) level basis set. Quenching mechanisms and electrical properties of fluorophores were explained with theoretical outcomes. Iodine doped and undoped oligoesters electrical conductivity were studied in solid-state and the conductivity was gradually increased with increase the contact time of iodine with oligoesters. At different frequencies and temperatures, the dielectric measurement was calculated using the two-probe method. Among all oligoesters, DMDAP exhibited high electrical conductivity and DMDMP has a higher dielectric constant value than other oligoesters.

Inhibition of Phase Transition in Amorphous Niobium Oxide by Covalent Carbon Reinforcement Enables Fast‐Charge and Long‐Duration Lithium Storage

AbstractNiobium oxides are potential anode materials for ultrafast and safe lithium‐ion batteries due to their high ionic conductivity and relatively high operation voltage. However, the electrochemically induced phase transformations that involve multi‐electron redox reactions in a wide voltage window cause rapid capacity degradation and poor rate capability. Here, a novel carbon‐covalent amorphous niobium oxide anode is reported to greatly suppress the phase transition during cycling via formation of strong Nb─O─C bonds, achieving high‐capacity, fast‐charge and long‐duration lithium storage. This amorphous structure and forming covalent carbon contribute to good volume accommodation and high electron conductivity. The carbon‐covalent amorphous Nb2O5 displays a high reversible capacity of 361.5 mAh g−1 at 0.1 A g−1 and excellent cycling stability with a capacity of 189.8 mAh g−1 at a high rate of 10 A g−1 after 9000 cycles. Structure characterizations reveal that the well‐preserved amorphous structure without phase transition during repeated Li+ insertion/desertion is responsible for the superior performance. This work opens a new avenue on rational design of high‐performance amorphous electrode materials for next‐generation batteries.

Novel PEO-based Solid Polymer Electrolyte with High Elasticity and High Ionic Conductivity for Room Temperature Lithium Metal Batteries

Abstract The development and application of polyethylene oxide (PEO) based solid polymer electrolyte (SPE) is severely constrained by its low ionic conductivity and poor tensile resistance. To improve the electrochemical performance of SPE without losing its mechanical properties, a benzene sulfonate-based additive is adopted into crosslinking system composed of -CH2-CH2-O- segments to obtain a membrane with a high ionic conductivity of 1.47×10-4 S cm-1 and an ionic transference number of 0.70 at room temperature. The activation energy value of 0.128 eV gives evidence for a favorable migration mechanism of PTH-SPE. Anti-dendrite growth and contact optimization can be realized by molecular structure design with a tensile elongation of 490%. The reversible overpotential of Li||Li symmetric cell within 1000 h demonstrates that the compact PTH-SPE can inhibit the growth of lithium dendrite. This work provides a new strategy for designing high-performance solid electrolytes for room temperature via a green solvent-free method.

Exploring the Water Oxidation Catalytic Activity of a Mn-Based Magnetic Metal-Organic Framework: The Role of Proton Conductivity and Oxygen Evolution Reaction Overpotential.

The present work evaluates the water oxidation catalytic activity of a Mn-based metal-organic framework (MOF), which we envisioned to reduce the oxygen evolution reaction (OER) overpotential because of its high electrical conductivity, facilitated by solvent-encapsulated structural features. The presence of Mn centers induces interesting magnetic features in the MOF, which exhibits impressive cryogenic magnetic refrigeration with a ΔSM value of 29.94 J kg-1 K-1 for a field change of ΔH = 5T at 2.3 K. To the best of our knowledge, the ΔSM value of the current system ranked the highest position among the published examples. The crystal structure aligns perfectly with the thematic expectations and features as many as ten metal-coordinated water molecules, forming an extensive web of a hydrogen-bonded network while facing toward the porous channel filled with another set of much-anticipated entrapped lattice water molecules. Such structural features are expected to manifest high proton conductivity, and detailed investigation indeed yields the best value for the system at 1.57 × 10-4 S/cm at 95% humidity and 85 °C. In order to evaluate the thematic notion of a one-to-one relationship between OER and improved electrical conductivity, extensive electrocatalytic water splitting (WS) investigations were carried out. The final results show highly encouraging WS ability of the Mn-MOF, showing the electrocatalytic surface area value of the active species as 0.0686 F/g with a turnover frequency value of 0.043 [(mol. O2) (mol. Mn-MOF)-1 s-1]. Another fascinating aspect of the current communication is the excellent synergy observed between the experimental WS outcomes and the corresponding theoretical data calculated using density functional theory (DFT). Consequently, a plausible mechanism of the overall OER and the role of the Mn-MOF as a water oxidation catalyst, along with the importance of water molecules, have also been derived from the theoretical calculations using DFT.

Variant-Localized High-Concentration Electrolyte without Phase Separation for Low-Temperature Batteries.

Dual-ion batteries (DIBs) present great application potential in low-temperature energy storage scenarios due to their unique dual-ion working mechanism. However, at low temperatures, the insufficient electrochemical oxidation stability of electrolytes and depressed interfacial compatibility impair the DIB performance. Here, we design a variant-localized high-concentration solvation structure for universal low-temperature electrolytes (ν-LHCE) without the phase separation via introducing an extremely weak-solvating solvent with low energy levels. The unique solvation structure gives the ν-LHCE enhanced electrochemical oxidation stability. Meanwhile, the extremely weak-solvating solvent can competitively participate in the Li+-solvated coordination, which improves the Li+ transfer kinetics and boosts the formation of robust interphases.Thus, the ν-LHCE electrolyte not only has a good high-voltage stability of >5.5 V and proper Li+ transference number of 0.51 but also shows high ionic conductivities of 1 mS/cm at low temperatures. Consequently, the ν-LHCE electrolyte enables different types of batteries to achieve excellent long-term cycling stability and good rate capability at both room and low temperatures. Especially, the capacity retentions of the DIB are 77.7% and 51.6 %, at -40 oC and -60 oC, respectively, indicating great potential for low- andtemperature energy storage applications, such as polar exploration,emergency communication equipment, and energy storage station in cold regions.

Study of conduction mechanisms of InSeSb nano-chalcogenide alloys

The electrical conduction mechanisms for bulk samples of In0.1Se0.9−x Sb x (x = 0, 0.04, 0.08 and 0.12) nano-chalcogenide system, synthesized by the melt-quenching technique are investigated through current–voltage (I–V) characteristics. For the detailed study of conduction mechanism pellets of bulk samples are prepared. A thorough examination of electrical conductivity is done in the temperature range of 295–318 K and 0–50 V voltage range. From I–V measurements it is observed that samples are showing ohmic nature at lower field and non-ohmic nature at relatively higher field values. The temperature dependence of DC conductivity is analyzed using the Arrhenius relationship which is found to increase with Sb content. The value of activation energy and pre-exponential factor are calculated, which revealed that the conduction is due to the hopping of charge carriers among the localized states. Different parameters of Mott’s variable range hopping such as degree of disorder T 0, density of localized states N(E F), hopping distance (R hop), and hopping energy (W) are calculated. For the high field conduction process Poole–Frenkel, and Schottky processes are studied.

A networked iron and nitrogen-doped ZIF-8/MWCNTs heterostructure for oxygen reduction reaction.

Zeolitic Imidazolate Frameworks-8 (ZIF-8) is commonly used as an ideal precursor for non-noble metal catalysts because of its high specific surface area, ultra-high porosity, and N-rich content. Upon pyrolyzing ZIF-8 at 900 °C in Ar, the resulting material, referred to as Z8, displayed good activity toward the oxygen reduction reaction (ORR). Then the ZIF-8 was mixed with various conductive carbon materials, such as multiwall carbon nanotubes (MWCNTs), Acetylene black (ACET), Vulcan XC-72R (XC-72R), and Ketjenblack EC-600JD (EC-600JD), to form Z8 composites. The Z8/MWCNTs composite exhibited enhanced ORR activity owing to its network structure, meso-/microporous hierarchical porous structure, improved electrical conductivity, and graphitization. Subsequently, iron and nitrogen co-doping is achieved through the pyrolysis of a mixture comprising Fe, N precursor, and ZIF-8/MWCNTs, which is denoted as FeN-Z8/MWCNTs. The intrinsically high electrical conductivity of MWCNTs facilitated efficient electron transfer during the ORR, while the meso-/microporous hierarchical porous structure and network structure of Fe, N co-doped ZIF-8/MWCNTs promoted oxygen transport. The presence of Fe-containing species in the catalyst acted as activity centers for ORR. This strategy of preparing Z8 composites and modifying them with Fe, N co-doping offers an insightful approach to designing cost-effective electrocatalysts.

Diminish charge loss by mica incorporation into nylon nanofibers for performance enhancement of triboelectric nanogenerators operating in harsh ambient

The triboelectric nanogenerator (TENG) is a fascinating energy-harvesting device that utilizes the triboelectric effect caused by contact electrification and electrostatic induction. Nylon 66 is used widely in TENG applications because it is a representative tribo-positive polymer with excellent biocompatibility. On the other hand, the generated charges are vulnerable to discharge due to moisture in the air, which impedes the TENG performance in harsh environments. Moreover, the dielectric loss, which generates heat by consuming the considerable electric charge in triboelectric materials, significantly degrades the TENG performances. This study fabricated the composite nanofiber (NF) structure of nylon 66 and mica, which has excellent electrical insulation, low dielectric loss, high thermal conductivity, and enhanced tribo-positive properties, to circumvent these problems. Embedding the mica into the nylon NFs enhanced the TENG performance and prevented performance degradation even in harsh environments at a relative humidity of 70%. Furthermore, after 100,000 cycles of friction, the nylon/mica composite NFs showed smaller temperature increments than the pristine nylon NF because of the low dielectric loss and efficient heat dissipation of the mica. The nylon/mica composite NFs were applied to a sustainable and wearable power generator operating in a humid and hot environment by attaching the device to the forearm and soles of the feet. The generators were efficient enough to turn on 80 light-emitting diodes.

Characterization of Mixtures of Rugulopteryx okamurae Compost and Plant Residues to Determine the Most Effective Composition as a Substrate and Source of Nutrients

The increasing invasion of Rugulopteryx okamurae algae along the coast of southeastern Spain has prompted efforts to explore its potential as a resource. Consequently, composting this alga is considered a viable solution for agricultural applications. This study investigates the composting process of mixtures of R. okamurae seaweed with plant residues and characterizes the final compost for its use as a substrate and/or source of nutrients to determine the most effective composition of the mixture. The composting process was conducted using varying proportions of seaweed (100%, 30–35%, and 15%) combined with plant residues (from vegetable plants, fruits, and gardens) and included both washed and unwashed seaweed. The first trials revealed challenges associated with Rugulopteryx okamurae, such as a low C/N ratio and algae washing. Consequently, a second trial was conducted to optimize the mixtures, aiming for a C/N ratio close to 30. Additionally, it was decided not to wash the algae to reduce the electrical conductivity (EC) in the mixtures. The findings indicate that the composting process remains unaffected by high electrical conductivity when algae are unwashed. However, washing the algae before composting did affect the compost quality, as the composts with washed algae with garden waste (SwP 34.0 dS m−1) had a lower electrical conductivity (EC) than did the unwashed composts with garden waste (SP 51.6 dS m−1 and SFP 64.9 dS m−1). On the other hand, the compost-only horticultural and garden waste (FHP 43.7 dS m−1) had a high EC; therefore, the EC was not increased with low proportions of unwashed algae, as was seen with the compost with 15% unwashed algae (SFHP 47.6 dS m−1). The other quality parameters were not affected by the absence of algae washing at the beginning of the composting process.

Influence of Cryogenic Coated Copper Tool Electrode in Electrochemical Micro Machining process of Stainless Steel 316

Electrochemical micro-Machining (ECMM) is best suited for machining micro level profiles as it provides several advantages like better precision, less wear and machinability of wide range of materials. Using various levels of process parameters like voltage, electrolyte concentration, frequency and duty cycle, electrochemical micro machining was performed using untreated and cryogenic treated electrodes and its effect on various response parameters while machining Stainless Steel 316 are studied. From results obtained, the cryogenic treated tool electrode had a high MRR,9.8% of lower overcut,11.2 % of lower conicity and 3.8% of higher circularity compared to untreated tool electrode because the treated tool has high electrical conductance, high corrosion resistance and smaller grain size. The optimized values for Cryogenic Treated tool was achieved when applied voltage was 10V, electrolyte concentration was 30 g/L, frequency was 50 Hz and duty cycle was 33%.

Salt-Assisted, In Situ Current Nanowelding of an Interfacial Au Nanoparticle Film for a High-Performance Electrocatalyst.

Interfacial self-assembly is a well-established method for the preparation of a two-dimensional (2D) metal nanofilm from nanoscale building blocks. However, the as-prepared nanofilm exhibits limited conductivity because of the large contact resistance at the junctions among its building blocks. Here, we report a salt-assisted, in situ current nanowelding strategy to weld an interfacial Au nanoparticle (NP) film for downstream applications, such as high-performance electrocatalysts. Particularly, we found that salt-assisted interfacial assembly can reduce the size of the nanogaps among neighboring Au NPs and, in turn, greatly improve the conductivity of the resultant Au NP film. Consequently, the Au NP film can be readily welded using current, and the welding extent can be monitored in real-time by looking at the passing current. The welding finally produces a nanoporous Au film (NPGF) with a network nanostructure, high conductivity, and abundant active sites so that it delivers a large current density of 86.96 μA·cm-2 (1.81 times higher than that from the pristine Au NP film) and shows improved cycling stability for methanol electrooxidation. Thus, these results offer a low-cost, solution-processable approach for the fabrication of a large-area, interconnected nanofilm from nanoscale building blocks beyond Au NPs, which may find diverse downstream applications.

Optimizing electrical and thermal performance in AlGaN/GaN HEMT devices using dual‐metal gate technology

AbstractThe investigation of aluminum gallium nitride/gallium nitride high electron mobility transistor (AlGaN/GaN HEMT) devices with a dual‐metal gate (DMG) structure encompasses both electrical and thermal characteristics. As efforts to enhance heat dissipation progress, there is a concurrent exploration of novel semiconductor materials boasting high thermal conductivity, like boron arsenide and phosphide. Combining these materials into a model and measuring their interface achieves efficient energy transport. Minimizing the self‐heating impact in AlGaN/GaN HEMTs is essential for enhancing device efficiency. This research exposes the heterogenous combination of boron arsenide and phosphide cooling substrates with metals, GaN semiconductors and HEMT. In this research, the autoencoder deep neural network techniques in GaN HEMT for self‐heat reduction is driven by the ability to effectively analyze and model the thermal behavior of the device. Autoencoders learn complex relationships within temperature data and identify patterns associated with self‐heating. By leveraging these learned representations, the deep neural network optimizes control strategies to mitigate self‐heating effects in GaN HEMT devices, ultimately contributing to improved thermal management and enhanced overall performance. In this research, the use of genetic algorithms in GaN HEMT aims to optimize device parameters systematically, to minimize self‐heating effects and enhance overall thermal performance. The structure also enhances electron mobility within the channel. Results show DMG structures, exhibiting higher saturation output currents and transconductance despite self‐heating. The DMG exhibits a maximum gm value of 0.164 S/mm, which is 10% higher significantly enhancing GaN‐based HEMTs for improved reliability and efficiency in various applications.