Composite Conductors Research Articles

"Synergistic Hybridization of Mn-MOF@rGO and Ti3C2 for High-Performance Supercapattery Devices and Hydrogen Evolution Reaction"

The burgeoning interest in two-dimensional (2D) materials stems from their heightened storage capacity and superior conductivity. Here, we synthesized a metal-organic framework of manganese (Mn-MOF) and introduced reduced graphene oxide (rGO) doping into this heterostructure using a hydrothermal method. Subsequently, Ti3C2Tx MXene was prepared via a template method. The Mn-MOF@rGO was then combined with Ti3C2Tx MXene in a 50/50 wt% ratio using hydrothermal techniques, and their structural and electrochemical characteristics were evaluated. In 3-electrode measurements, the MnMOF@rGO/Ti3C2Tx composite conductor exhibited a precise capacity of 2645 C/g (5.29 C/cm3) at 1.8 A/g. Furthermore, a hybrid device termed a supercapattery was fabricated employing MnMOF@rGO/Ti3C2Tx along with activated carbon (AC) composite electrodes, demonstrating remarkable energy density of 67 Wh/kg and an impressive power density of 880 W/kg. After 8,000 cycles, the electrode exhibited 84% capacity retention and maintained 92% columbic efficiency. In the hydrogen evolution reaction (HER), the MnMOF@rGO/Ti3C2Tx composite displayed a minimal Tafel slope of 54.65 mV/dec. These two-dimensional composite electrodes offer novel avenues for the advancement of high-performance energy device.

Electrochemical Hydrogen Pump Using CsH2PO4/SnO2 Composite Proton Conducting Membrane

Liquid organic hydrogen carriers (LOHCs) are molecular compounds that have potential to be a promising class of hydrogen storage materials. Upon thermal treatment and in the presence of catalysts, H2-rich LOHCs can give off H2 without phase change. One immediate example is methylcyclohexane (C7H14) (MCH) conversion to toluene (C7H8) (TOL). The rate of H2 production of LOHC’s dehydrogenation reaction is kinetically limited. Therefore, adequate catalysts can help boost kinetics. An alternative approach to overcome the kinetic limitation is to shift the dehydrogenation reaction by removing H2 in the product via either a chemical or electrochemical route. Here we show an electrochemical H2 pump concept to promote the dehydrogenation reaction of MCH to TOL by pumping out H2 from the product line. We selected the super-protonic conductor CsH2PO4 (CDP) as the electrolyte for the pump due to the operating temperature of the dehydrogenation reaction (250-350 oC). However, CDP would not be stable if there is an insufficient amount of H2O (<38%) in the working environment, irreversibly dehydrated into a low-conductivity phase. On the other hand, too much H2O in MCH stream would negatively affect the catalytic performance of MCH-to-TOL conversion. Therefore, it is critical to limit the H2O content in MCH stream without affecting H2 pump performance.Here, we report the use of SnO2 to stabilize the super-protonic conducting phase in CDP. SnO2 is a super-hydrophilic material. We first show the ionic conductivity stabilization over a broad H2O content to demonstrate the effectiveness of SnO2 in stabilizing CDP conductivity. We then show the performance of H2 pump based on the composite CDP-SnO2 protonic conductor. We also show materials characterization results including XRD, SEM and Raman to facilitate our understanding of the observed improvement and degradation. Overall, this study provides a supporting method to accelerate the production of green hydrogen with LOHCs.

Experimental Study of Magnetization Loss by External Magnetic Field in CORC-TSTC Hybrid Composite Conductor

Experimental Study of Magnetization Loss by External Magnetic Field in CORC-TSTC Hybrid Composite Conductor

Quench protection for high-temperature superconductor cables using active control of current distribution

Superconducting magnets of future fusion reactors are expected to rely on composite high-temperature superconductor (HTS) cable conductors. In presently used HTS cables, current sharing between components is limited due to poorly defined contact resistances between superconducting tapes or by design. The interplay between contact and termination resistances is the defining factor for power dissipation in these cables and ultimately defines their safe operational margins. However, the current distribution between components along the composite conductor and inside its terminations is a priori unknown, and presently, no means are available to actively tune current flow distribution in real-time to improve margins of quench protection. Also, the lack of ability to electrically probe individual components makes it impossible to identify conductor damage locations within the cable. In this work, we address both problems by introducing active current control of current distribution between components using cryogenically operated metal-oxide-semiconductor-field-effect transistors (MOSFETs). We demonstrate through simulation and experiments how real-time current controls can help to drastically reduce heat dissipation in a developing hot spot in a two-conductor model system and help identify critical current degradation of individual cable components. Prospects of other potential uses of MOSFET devices for improved voltage detection, AC loss-driven active quench protection, and remnant magnetization reduction in HTS magnets are also discussed.

Copper-Graphene Composite (CGC) Conductors: Synthesis, Microstructure, and Electrical Performance.

Improving the electrical performance of copper, the most widely used electrical conductor in the world is of vital importance to the progress of key technologies, including electric vehicles, portable devices, renewable energy, and power grids. Copper-graphene composite (CGC) stands out as the most promising candidate for high-performance electrical conductor applications. This can be attributed to the superior properties of graphene fillers embedded in CGC, including excellent electrical and thermal conductivity, corrosion resistance, and high mechanical strength. This review highlights the recent progress of CGC conductors, including their fabrication processes, electrical performances, mechanisms of copper-graphene interplay, and potential applications.

Temperature distribution analysis of gap type conductors and carbon fiber composite core conductors based on finite element

Temperature distribution analysis of gap type conductors and carbon fiber composite core conductors based on finite element

Liquid metal-enhanced self-healing dual-hard-phase cross-linked waterborne polyurethane for flexible sensors

Flexible strain sensors are increasingly recognized in areas such as health monitoring, mechanical operations, and infrastructure due to their ability to detect minute mechanical signals and conform to irregular surfaces. As sophisticated smart materials, these sensors demand exceptional sensitivity, durability, and robust self-healing capabilities. In this paper, methyl 2,6-dihydroxybenzoate and 2,2′-diaminodiphenyl disulfide were introduced into waterborne polyurethane to form a dual-hard-phase crosslinked matrix, which is characterized by dynamic covalent disulfide bonds and reversible hydrogen bonds. The resultant WPU-D5B2 material exhibits outstanding tensile strength (34.80 MPa) and toughness (190.5 MJ m−3), with a 97.4 % degree of self-healing at 50 ℃ for 2 h. Remarkably, this material maintains 83 % of its original mechanical performance even following recycling processe. This method significantly enhances the performance of flexible strain sensors in complex environments. Consequently, a composite conductor was prepared by blending self-healing waterborne polyurethane (WPU), graphene oxide (GO), and liquid metal (LM). Graphene oxide formed an efficient electronic conductive network, while liquid metal served as a conductive medium, filling microgaps to maintain the integrity of the electron pathway. This innovative dual-conductive mechanism ensures reliable performance in applications such as advanced flexible sensors.

Study on current carrying capacity calculation model for dynamic capacity increase of carbon fiber reinforced composite core conductor

Abstract With the “dual-carbon” as the goal of the new power system construction gradually in-depth, transmission lines must have energy-saving capacity for the direction of development. A new type of large-capacity overhead transmission conductor is the carbon fiber reinforced composite core (CFCC) conductor. The conductor has high capacity, low loss, high-temperature resistance, low high-temperature sag, and other characteristics. It is one of the key technologies and equipment applied to the transformation of old overhead transmission lines to enhance its capacity. At the same time, it can also realize the dynamic transmission capacity regulation of the overhead line. The application of the prospect is very promising. The accurate assessment and calculation model for the conductor’s allowable current carrying capacity is the key core technical problem of the overhead transmission line dynamic capacity increase capability. The paper establishes a maximum allowable current capacity calculation model for carbon fiber-reinforced composite core conductors based on Morgan’s formula. The results of the load flow calculation are compared with the actual load flow test results to verify the calculation model, and the maximum error is 3.59%, which proves the reliability of the calculation model. On this basis, the influence of external environmental factors (ambient temperature, sunlight intensity, wind speed, and direction) on the maximum allowable current capacity of the conductor is discussed. The correlation coefficient of the model is analyzed.

Self‐healing waterborne polyurethane elastomers based on synergistic hydrogen, disulfide and borate bonding for composite conductors

AbstractAs a functional material, polyurethane elastomers have found different applications in a variety of fields such as flexible electronics and smart coatings, but due to the damage during use, they are often endowed with self‐healing properties. However, conventional intrinsically self‐healing polyurethanes often don't balance excellent mechanical and self‐healing properties, so it has become crucial to prepare polyurethane elastomers with excellent self‐healing properties and high mechanical properties. In this study, a self‐healing waterborne polyurethane elastomers (IP‐DTDAx‐BAy‐WPU‐n) was synthesized based on 4, 4‐diaminodiphenyl sulfide (DTDA) boronic acid (BA). The disulfide bond has high motility at low temperatures and induces molecular‐level healing at the damaged interface, contributing to good repair under mild conditions. The borate ester bond limits intermolecular chain slippage and improves the mechanical properties as a dynamic cross‐linking point, while its dynamic reversible effect can synergistically improve the self‐healing ability. The results show that the synthesized elastomer films have good mechanical properties (strength 23.21 MPa, elongation at break 1259.08%, toughness 83.28 MJ m−3), good elastic recovery and self‐healing properties (93%). Furthermore, a composite conductors (IP‐DTDAx‐BAy‐WPU/AgNWs) with self‐healing properties was prepared by compositing AgNWs nanowires with polyurethane elastomers, which laid the foundation for its application in flexible electronic devices and wearable sensing devices.

Efficient ionic transport over wide temperature range in oxide enabled by interfacial reaction of molten carbonate

The development of solid oxide fuel cell (SOFC) operated at low and intermediate temperatures is limited by the poor performance of inorganic ionic conductors. Oxide-based ion conductors have attracted much attention due to their excellent stability and tunable ion conduction behavior. In this study, we propose a new approach for the construction of regulated ionic transport pathways in a composite oxide ionic conductor made of WO3/ZrO2 (WZ) and (Li0.68K0.32)2CO3. The interfacial reaction between WO3/ZrO2 and (Li0.68K0.32)2CO3 is used to enhance the interaction between the oxide and carbonate interfaces and introduce hydrophilic phases for water retention, thus achieving ultra-high ionic conductivity of the oxide/carbonate composites at low and intermediate temperatures. The optimal ionic conductor, 13WZ-30(Li0.68K0.32)2CO3 (13WZ-30C), has a superior ionic conductivity of 25.8-6.28 mS cm−1 from room temperature to 250 °C. The ion conduction mechanism of the composite is investigated. This study emphasizes the significance of interfacial chemistry regulation between oxides and carbonates for achieving superior ion conduction performance.

Three Dimensional Graphene/Copper Dual Networks as Composite Conductors with Enhanced Current Carrying Capacity

Three Dimensional Graphene/Copper Dual Networks as Composite Conductors with Enhanced Current Carrying Capacity

Investigation on the Novel High-performance Copper/Graphene Composite Conductor for High Power Density Motor

Investigation on the Novel High-performance Copper/Graphene Composite Conductor for High Power Density Motor

Detection of hidden defects of multi-strand carbon fiber composite core conductor based on optical fiber sensing technology

Detection of hidden defects of multi-strand carbon fiber composite core conductor based on optical fiber sensing technology

Carbon fiber composite core conductor operation risk assessment model based on various types of monitoring data

Abstract As the national economy grows gradually and the scale of urbanization expands, the standard for power transmission is also continuously increasing. Currently, the existing transmission lines can no longer meet the rising power demand, thus urgently requiring the construction of power transmission capacity expansion. Although there are many strategies for increasing capacity, the development of enhanced conductor material is indeed its greatest advantage. However, among the various options for increasing capacity, the development of capacity-enhancing wires is also the most advantageous. Carbon fiber conductors, which are known as “black gold,” are the perfect material for this purpose. Given the inherent economic value, high brittleness, and complexity of the installation process of carbon fiber materials, this study proposes an operational risk assessment model for carbon fiber composite core conductors based on multiple monitoring data. For the first time, the influence between quarterly lightning strike probability and arc droop as well as the temperature drop effect on overhead transmission conductors by convective heat dissipation from natural wind are taken into account. The expected arc sag size of the conductor in the future period can be predicted according to the meteorological forecast, which can effectively prevent the impact of flashovers and wire breakage on the operation of the power grid. In addition, the practicality and functionality of the assessment model have been verified by real accident data.

Advancing the pressure sensing performance and biocompatible of conductive rGO/PEDOT/PDMS composite film for simple and efficient pressure sensor

Recently, the demand for superior wearable strain sensors has been growing steadily with the widespread application of stretchable electronics. Based on polydimethylsiloxane (PDMS) and poly(3,4-ethylenedioxythiophene) (PEDOT):polystyrene sulfonate, it has good compatibility with graphene doping. Herein, an uncomplicated and capable pressure sensor based on PEDOT/PDMS-wrapped free-standing reduced graphene oxide (rGO) was devised and manufactured. The graphene-containing composite conductor exhibits superb electrical conductivity, resilience, and piezoresistive effect, and surprisingly exhibits excellent antibacterial capabilities and cycling constancy. The fast response and recovery times of this pressure sensor are below 9 and 21 ms, respectively. The magnitude of current changes did not fluctuate significantly after 10 000 cycles of use, which indicates the great dependence of the sensor. Strain sensors as one of primary demand is that composite conductors are attached straight to the mortal skin (joints, elbows and knees) for actual-time monitoring.

A highly stretchable and sintering-free liquid metal composite conductor enabled by ferrofluid

Stretchable and highly conductive elastomers with intrinsically deformable liquid metal (LM) fillers exhibit promising potential in soft electronics, wearables, human-machine interfaces, and soft robotics. However, conventional LM-elastomer (LME) conductors require a high loading ratio of LM and the post-sintering to rupture LM particles to achieve electric conductivity, which results in high LM consumption and process complexity. In this work, we presented a straightforward and post-sintering-free method that utilizes magnetic aggregation to fabricate stretchable LME conductors. This was achieved by dispersing LM ferrofluid into the elastomer precursor, followed by applying the magnetic field to induce the aggregation and interconnection of the LM ferrofluid particles to form conductive pathways. This method not only simplifies the preparation of initially conductive LME but also reduces the LM loading ratio. The resulting conductive LME composites show high stretchability (up to 650% strain), high conductance stability, and magnetic responsiveness. The stretchable LME conductors were demonstrated in various applications, including the creation of flexible microcircuits, a magnetically controlled soft switch, and a soft hydrogel actuator for grasping tasks. We believe the stretchable LME conductors may find wide applications in electronic skins, soft sensors, and soft machines.

Current carrying capacity and failure mechanism of nitrogen-doped graphene/copper composite film

Graphene-copper composite conductors with a high current-carrying capacity hold significant promise for electronic applications. They combine the abundant charge carrier density of copper with the superior charge carrier mobility of graphene. In this paper, a nitrogen-doped graphene/copper film (NGC) nanocomposite conductor were developed by in-situ growth of nitrogen-doped graphene on a copper film. Furthermore, the current-carrying properties and failure mechanisms of NGC were investigated by varying the proportion of nitrogen-doped graphene in the composite conductors. The results reveal that the conductivity of a 576 nm copper film increases to 5.509×107S·m−1 when coated with a 20 nm layer of nitrogen-doped graphene, which reaches 104.7% of the conductivity of the copper film (5.263×107S·m−1). In addition, the current-carrying capacity of the NGC conductor (4.96×107A·cm−2) experiences a 21% enhancement when compared with the capacity of the copper film (4.10×107A·cm−2). Microstructural characterization has confirmed that Joule heat constitutes the primary factor influencing the breakdown of the composite conductor. In particular, the introduction of nitrogen-doped graphene has led to an improvement in the thermal conductivity of the NGC conductor.

FFT based iterative schemes for composite conductors with uniform boundary conditions

In the present paper, we extend the FFT method to deal with the homogenization problem of composite conductors with uniform boundary conditions. The principle of the approach consists of applying a transformation to build a periodic problem from the solution with uniform boundary conditions. It is shown that the related periodic problem must be applied to an extended domain obtained by mirror symmetry of the unit cell. The conductivity equation must then be solved on this extended domain under an applied periodic polarization field as a loading parameter. Illustrations are provided and the effective conductivity obtained with FFT is compared to finite element solutions to validate the approach. The proposed method can be applied to microstructure geometries of all kinds, including cells obtained through imaging devices.

PEDOT:PSS/Natural Rubber Latex Inks for Screen‐Printing Multifunctional Wearable Strain–Humidity Sensors

Wearable strain–humidity sensors are increasingly recognized for their role in healthcare and detecting human motion signals. However, many strain–humidity sensors require complex manufacturing processes and have limited applicability. In this study, based on the good miscibility between natural rubber latex (NRL) and poly (3,4‐ethylenedioxythiophene):poly (4‐styrenesulfonate) (PEDOT:PSS), PEDOT:PSS/NRL composite conductors are transferred onto fabric substrate through screen printing and prepared high‐performance strain–humidity sensor. The PEDOT:PSS/NRL blends strain–humidity sensor exhibited good stability and durability (500 cycles) at 10% strain, achieves a gauge factor (GF) of 123.8 with excellent linearity, making it operational in detecting various human motions, such as finger bending, elbow bending, wrist bending, and so on. In addition, the PEDOT:PSS and water molecules interaction results in a humidity response time as low as 0.72 s and recovery time as low as 0.85 s for the PEDOT:PSS/NRL composite strain–humidity sensor, and a wide relative humidity detection range (6–83%), allowing it to be utilized for precise detection of human breathing. Furthermore, it can monitor the use's joint movement, facial muscle movement, and respiratory rate, which show its potential application prospect in health monitoring.

Analytical and experimental studies of the improved conductance-stability and stretchability of the liquid metal-embedded composites based on novel continuous annular-shaped branch channels

Stretchable and conductance-stable composites are critical for progress in flexible electronics. Tremendous efforts have focused on engineering electrical conductors from liquid metal-embedded elastomers. While these elastomers enable elastic compliance and deformability, the embedded liquid metal is vulnerable to puncture that causes undesired electrical failure, and most of the conductive elastomers are strain-sensitive with degenerative conductance upon deformations. Here, we combined analytical and numerical analyses with experimental studies to investigate the effects of the innovatively designed continuous annular-shaped branch channels, inspired by the Tesla valve, on the performances of the LM-embedded conductive composite. Theoretically, in the process of mechanical deformations, the as-proposed continuous annular-shaped architecture can dissipate the pressure energy of the fluidic LM to enhance the fracture toughness of the composite, while the LM flow could be accelerated as the deformation was removed to maintain the percolated conductive path, leading to excellent conductive stability. Experimentally, the as-fabricated composite conductor with continuous annular-shaped branch channels can be stretched up to ∼80% (more than two times higher than conventional LM-embedded composite), and upon fully activating the conductive pathway, a very high conductivity of ∼4 × 104 S m−1 and conductance change of less than 2% under varied deformations, including stretching, flexing, twisting and compressing, are realized. It is believed that this novel design strategy will extend the understanding and application opportunities of LM as functional materials in the development of flexible electronics.