Exceptional Electrical Conductivity Research Articles

High-entropy alloy anodes for low-strain and high-volumetric lithium-ion storage at ambient and subzero temperatures

The pursuit of lithium-ion batteries with higher energy density and longer lifespan has led to significant interest in anode materials that operate according to the alloying mechanism due to their high specific capacity. However, their poor structural and electrochemical stability presents a significant challenge to achieving reliable cyclability. In this study, a high-entropy stabilized SnSbMnBiTe alloy anode with a mixing entropy of 1.61 R is reported, exhibiting exceptional electrical conductivity, tapping density, and Young's modulus. These unique characteristics enable the designed high-entropy anode to demonstrate a high volumetric capacity of 2408.4 mA h cm−3 at 0.1 A g–1, exceptional rate capability with the capacity of 1017.4 mA h cm−3 at 5A g–1, and impressive subzero-temperature performance with a discharge capacity of 1418.0 mA h cm−3 at -30 °C. In-situ transmission electron microscopy reveals that the high-entropy anode undergoes much-suppressed volume expansion compared to the low-entropy counterpart, despite delivering high capacity, explaining its excellent structural and electrochemical reversibility. The results obtained in this study provide valuable insight into the design of anode materials for rechargeable batteries.

High-performance flexible organic gas sensor via alkyl side chain engineering of polyalkylthiophene

Poly(3-alkylthiophene) (P3AT) is a representative p-type organic semiconductor with a distinctive molecular structure that incorporates a π-electron system, promoting charge carrier mobility and providing exceptional electrical conductivity. The alkyl side chain linked to the π-electron backbone was found to have a significant effect on charge carrier transport and mechanical properties. This study presents a comprehensive comparison of the gas-sensing performances of various gases (NO2, SO2, and CO2) and the mechanical properties of gas sensors fabricated from P3AT with alkyl chain lengths of 6, 8, 10, and 12 (P3HT, P3OT, P3DT, and P3DDT). Our investigations revealed that as the alkyl side chain length increased, the gas sensor performance significantly improved owing to the increase in free volume, concurrently promoting improved flexibility. The P3DDT sensor exhibited a sensitivity approximately twice that of the P3HT sensor, along with superior mechanical flexibility owing to its free volume.

Facile fabrication of AgFeS2 nanostructure via hydrothermal route for supercapacitor application

This study presents the electrochemical performance of AgFeS2 as an electrochemical energy storage material, highlighting its notable attributes such as exceptional electrical conductivity and abundant availability. AgFeS2 nanostructure was successfully fabricated utilizing single-step hydrothermal technique. Physiochemical characterization and electrochemical characterization, are both performed on the synthesized AgFeS2 nanostructure. An AgFeS2 sample on a nickel foam substrate was used to investigate the capacitance property of the materials. The Ag and Fe ions provide a synergistic contribution to the redox process that accelerates the electrochemical efficacy of the supercapacitor. An AgFeS2 nanostructure in a three-electrode system's galvanometric charge-discharge (GCD) profile showed a large specific capacitance (Cs) of 555 F g−1 @ 1 A g−1 in the potential range of 0 to 0.7 V (Ag/AgCl) and capacitive retention of 87 % over 7000th in 2.0 M KOH. The symmetric analysis depends on the AgFeS2 electrode has a high CS of 331 F g−1 at 1 A g−1 in an aqueous 2.0 M KOH in a two- electrode system. The AgFeS2 electrode-based symmetric supercapacitor has a specific power of 0.261 W kg−1 and a specific energy of 45 Wh kg−1. The capacitive results indicates that the AgFeS2 electrode is potential candidate for supercapacitor applications and it can also be employed in various fields such as water splitting, water remediation and photocatalysis.

Scalable fabrication of free-standing and integrated electrodes with commercial level of areal capacity for aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) present a highly promising avenue for the deployment of grid-scale energy storage systems. However, the electrodes fabricated through conventional methodologies not only suffer from insufficient mass loadings, but also are susceptible to exfoliation under deformations. Herein, a scalable and cost-effective freezing-thawing method is developed to construct free-standing and integrated electrode, comprising H11Al2V6O23.2, carboxymethyl cellulose, and carbon nanotubes. Benefiting from the synergistic effect of these components, the resultant electrode exhibits superior flexibility and robustness, large tensile strength, exceptional electrical conductivity, and favorable electrolyte wettability. Under a large mass loading of 8 mg cm−2 (corresponding to a negative/positive electrode capacity ratio of 2.09), the electrode achieves remarkable capacity of 345.2 mAh/g (2.76 mAh cm−2) at 0.2 A/g and maintains 235.2 mAh/g (1.88 mAh cm−2) at 4 A/g, while sustaining an impressive capacity retention of 97.7 % over 5000 cycles. These considerably outperform conventional electrodes employing traditional binders. Even at an elevated mass loading of 14 mg cm−2 or when operated at a low temperature of − 30 °C, the electrode continues to deliver excellent electrochemical performance (e.g., extraordinary areal capacity of 4.32 mAh cm−2). In addition, the electrode owns outstanding tolerance to external forces. This research contributes to our understanding of the pivotal challenges within the realm of AZIB technology.

Mechanics and Crack Analysis of Irida Graphene Bilayer Composite: A Molecular Dynamics Study

In this paper, we conducted molecular dynamics simulations to investigate the mechanical properties of double-layer and monolayer irida graphene (IG) structures and the influence of cracks on them. IG, a new two-dimensional material comprising fused rings of 3-6-8 carbon atoms, exhibits exceptional electrical and thermal conductivity, alongside robust structural stability. We found the fracture stress of the irida graphene structure on graphene sheet exceeds that of the structure comprising solely irida graphene. Additionally, the fracture stress of bilayer graphene significantly surpasses that of bilayer irida graphene. We performed crack analysis in both IG and graphene and observed that perpendicular cracks aligned with the tensile direction result in decreased fracture stress as the crack length increases. Moreover, we found that larger angles in relation to the tensile direction lead to reduced fracture stress. Across all structures, 75° demonstrated the lowest stress and strain. These results offer valuable implications for utilizing bilayer and monolayer IG in the development of advanced nanoscale electronic devices.

Superelastic Cellulose Sub-Micron Fibers/Carbon Black Aerogel for Highly Sensitive Pressure Sensing.

Superelastic aerogels with rapid response and recovery times, as well as exceptional shape recovery performance even from large deformation, are in high demand for wearable sensor applications. In this study, a novel conductive and superelastic cellulose-based aerogel is successfully developed. The aerogel incorporates networks of cellulose sub-micron fibers and carbon black (SMF/CB) nanoparticles, achieved through a combination of dual ice templating assembly and electrostatic assembly methods. The incorporation of assembled cellulose sub-micron fibers imparts remarkable superelasticity to the aerogel, enabling it to retain 94.6% of its original height even after undergoing 10000 compression/recovery cycles. Furthermore, the electrostatically assembled CB nanoparticles contribute to exceptional electrical conductivity in the cellulose-based aerogel. This combination of electrical conductivity and superelasticity results in an impressive response time of 7.7ms and a recovery time of 12.8ms for the SMF/CB aerogel, surpassing many of the aerogel sensors reported in previous studies. As a proof of concept, the SMF/CB aerogel is utilized to construct a pressure sensor and a sensing array, which exhibit exceptional responsiveness to both minor and substantial human motions, indicating its significant potential for applications in human health monitoring and human-machine interaction.

Recent Developments in Nanostructured Materials for Supercapacitor Electrodes

This review focuses on nanostructures-based systems and aims to provide a comprehensive overview of recent advancements in energy storage technologies and modified energy storage materials. The transition towards a sustainable and carbon-free energy system hinges on the progress of efficient and safe energy storage technologies. Supercapacitors have garnered significant interest in diverse energy storage applications due to their rapid charge/discharge rates, high power density, and extended cycle life. Nanostructures have conclusively demonstrated their capability to significantly enhance supercapacitor electrodes' performance. MXene, an innovative category of 2D materials, has emerged as a promising candidate for energy storage applications due to its substantial surface area, exceptional electrical conductivity, and versatile characteristics. Supercapacitors, nanostructures, and MXene are the main topics of the research articles and reviews in this special issue, highlighting recent developments in the design, synthesis, and characterization of advanced energy storage materials and devices. Additionally, this study presents an in-depth investigation of various carbon-based nanomaterials, their synthesis techniques, and their performance in supercapacitors. It also emphasizes the potential of recycling waste materials for developing high-performance nanomaterials for energy storage applications. Finally, this review encourages further research and development of advanced energy storage technologies by giving readers a thorough overview of the current state-of-the-art and future directions in this rapidly expanding sector.

Photosynthetic Efficiency of Microalgae and Cyanobacteria on Reduced Graphene Oxide (RGO) Anode Surface for Utilization in Bio-Photovoltaics (BPV)

Bio-photovoltaics (BPV) is sustainable energy production technology that utilize photosynthetic organisms and convert it into electricity. This Study has been carried out to study the photosynthetic efficiency of three microalgae on a Reduced Graphene Oxide (RGO) anode surface. RGO, with its exceptional electrical conductivity and large surface area, presents an attractive platform for enhancing the performance of BPV systems. The work aims to investigate the combined effect of microalgae and RGO anodes for use in BPV technology. RGO was synthesized and characterized on which Chlorella vulgaris, Gloeocapsa and Synechocystis were allowed to grow. A model BPV system was assembled, incorporating the microalgae and cyanobacteria as photoactive agents and RGO as the anode surface. The system was subjected to different experimental condition and photosynthetic efficiency, current generation, and power output were collected and analysed. Results demonstrated a significant improvement in the photosynthetic activity of microalgae when cultured on the RGO anode surface. Chlorella Shows maximum Efficiency in terms of growth and current generation. Statistical analysis confirmed the reliability and significance of these findings. Our finding bridges a crucial knowledge gap in the field of BPV, highlighting the potential of microalgae-RGO systems for cleaner energy production.

Mechanically strong, flexible, and flame-retardant Ti3C2Tx MXene-coated aramid paper with superior electromagnetic interference shielding and electrical heating performance

Undesirable electromagnetic interference (EMI) created by modern electronic devices has detrimental effects on the performance of high-precision electronic devices, information security, and human health. Therefore, lightweight, flexible, robust, and easy-to-fabricate EMI shielding materials with integrated functions are highly desirable to combat electromagnetic pollution. Herein, we report a scalable and facile strategy to prepare a flexible Ti3C2Tx MXene-coated aramid paper (MAP) with high-efficiency EMI shielding and excellent electrical heating performance. The intertwined network by aramid fibers endows the aramid paper (AP) with superior mechanical properties. After selectively single/dual coating with MXene onto AP, the MAP maintains a superior tensile strength of 73.6 MPa and enormous folding endurance of 4156 times. Owing to the exceptional electrical conductivity of MXene, the MAP with a relatively low MXene content (∼9.0 wt%) exhibits excellent overall performance with an EMI shielding effectiveness (SE) of 38 dB and SE/t of 422.2 dB mm−1. It’s noteworthy that the EMI SE of the MAP remains almost unchanged (37.4 dB) even after experiencing 5,000 repeated bending cycles. Additionally, the MAP shows satisfactory Joule electric-heating capability (a heating temperature rise of 130 °C at a low driving voltage of 5 V) and excellent flame-retardancy. This work provides a feasible strategy for large-scale production of flexible EMI shielding paper with multifunctional properties for future wearable facilities.

PdMo Bimetallene Coupled with MXene Nanosheets as Efficient Bifunctional Electrocatalysts for Formic Acid and Methanol Oxidation Reactions.

In this study, we demonstrate a facile soft chemistry strategy for the in situ growth of two-dimensional (2D) ultrathin PdMo bimetallene tightly coupled with Ti3C2Tx MXene nanosheets (PdMo/Ti3C2Tx) using a robust stereoassembly process. The 2D PdMo bimetallene offers numerous unsaturated Pd atoms and simultaneously induces combined bimetallic alloy and strain effects, while the Ti3C2Tx matrix effectively optimizes the electronic structure of PdMo bimetallene via a face-to-face interface interaction and guarantees exceptional electrical conductivity. As a consequence, the newly designed PdMo/Ti3C2Tx nanoarchitecture expresses remarkable electrocatalytic properties for the formic acid and methanol electro-oxidation, in terms of large electrochemically active surface areas, ultrahigh catalytic activity, strong antipoisoning ability, and dependable long-term stability, all of which are better than those of conventional Pd nanoparticle catalysts supported by Ti3C2Tx and carbon matrices.

Self-healing electrical bioadhesive interface for electrophysiology recording

Electrical bioadhesive interfaces (EBIs) are standing out in various applications, including medical diagnostics, prosthetic devices, rehabilitation, and human–machine interactions. Nonetheless, crafting a reliable and advanced EBI with comprehensive properties spanning electrochemical, electrical, mechanical, and self-healing capabilities remains a formidable challenge. Herein, we develop a self-healing EBI by thoughtfully integrating conducting polymer nanofibers and a typical bioadhesive within a robust hydrogel matrix. The accomplished EBI demonstrates extraordinary adhesion (lap shear strength of 197 kPa), exceptional electrical conductivity (2.18 S m−1), and outstanding self-healing performance. Taking advantage of these attributes, we integrated the EBI into flexible skin electrodes for surface electromyography (sEMG) signal recording from forearm muscles. The engineered skin electrodes exhibit robust adhesion to the skin even when sweating, rapid self-healing from damage, and seamless real-time signal recording with a higher signal-to-noise ratio (39 dB). Our EBI, along with its skin electrodes, offers a promising platform for tissue-device integration, health monitoring, and an array of bioelectronic applications.

Preparation and Characterization of Corn Straw-Based Graphitized Carbon with Ferric Acetylacetonate as Catalyst

Graphitized carbon exhibits exceptional thermal stability, electrical conductivity, corrosion resistance, and various intricate physical and chemical properties. Consequently, it has found extensive applications in diverse fields, such as electrodes, refractory materials, nuclear reactors, and supercapacitors. However, natural graphite is a limited nonrenewable resource, so finding other materials, exploring reliable graphitization methods, and achieving efficient green graphite production as an essential trend in the future is essential. In this paper, with corn straw liquefied product (CSLP) as raw material, ferric acetone catalyst, using carbonization, catalytic graphitization preparation of corn straw based graphitic carbon (CSBGC). When the graphitization temperature was 850 °C and the amount of ferric acetylpropionate (Fe(acac)3) was 7.0 mmol/g, the graphitized carbon showed better graphitization, micro fragmentation structure, and more minor defects, which effectively reduced the graphitization temperature, and the graphitic carbon rate of corn straw (CS) reached 25.2%. This study not only presents a highly efficient approach for synthesizing superior biomass-derived graphite carbon but also introduces usable perspectives on using corn straws.

Layer-by-Layer Assembly of CTAB-rGO-Modified MXene Hybrid Films as Multifunctional Electrodes for Hydrogen Evolution and Oxygen Evolution Reactions, Supercapacitors, and DMFC Applications.

Exceptional electrical conductivity and abundance of surface terminations like-F- and OH- leading to hydrophilicity make the family of 2D transition metal carbides/nitrides and carbonitrides (MXene) excellent candidates for energy storage and conversion applications. MXenes, however, undergo restacking of nanosheets via van der Waals interaction, hindering the active sites, leading to slow electronic and ionic kinetics, and ultimately affecting their electrochemical performance. Herein, we report binder-free cetyltrimethylammonium bromide-reduced graphene oxide (CTAB-rGO)-modified MXene hybrid films on nickel foam as a promising noble metal-free multifunctional electrode synthesized via layer-by-layer assembly and dip coating techniques, which effectively reduce restacking while improving the kinetics. The properties of the as-prepared electrocatalysts are investigated using various physiochemical characterizations and electrochemical measurements to accomplish the objective of "creating one kind of electrocatalyst for multiapplication" with a thorough understanding of the relationship between the material structure, morphology, and electrocatalytic performance. In energy conversion, the synergetic effect of MXene and the CTAB-rGO support helped increase the catalytic activity of the composite for electrochemical water splitting, demonstrating a current density of 10 mA/cm2 at an overpotential (η) of 360 V and a Tafel slope value of 56.6 mV/dec for hydrogen evolution reaction and a current density of 10 mA/cm2 at an overpotential (η) of 179 mV and a Tafel slope value of 47.03 mV/dec for oxygen evolution reaction in an alkaline medium. The electrode material also exhibited a higher oxidation current density (373.60 mA/cm2) compared to that of synthesized MXene toward methanol oxidation reaction in direct methanol fuel cell application. Additionally, the energy storage potential of CTAB-rGO modified MXene as electrode materials for supercapacitors with a high specific capacitance (544.50 F g-1 at 0.5 A g-1) and a good capacity retention of 87% after 5000 cycles was studied. These findings of this work showcase the potential of the electrocatalyst in both conversion and storage of electrochemical energy.

Room temperature high thermoelectric performance of Bi-based full-Heusler compounds CsxRb[formula omitted]Bi with strong anharmonicity

Bismuth-based compounds have been identified as a class of promising candidates for the realization of high-performance thermoelectrics, derived from their exceptional electrical conductivity and intrinsic low lattice thermal conductivity κL. Here, we employed first-principles calculations, self-consistent phonon theory, and compressive sensing technique in conjunction with the Boltzmann transport equation to investigate the anharmonic thermoelectric properties of full-heusler bismuth compounds CsxRb3−xBi. As the Cs content increases, the κL of CsxRb3−xBi decreases due to impurity scattering effects, and then increases. Among them, at 300 K, Rb3Bi has the largest κL of 0.69 Wm−1K−1, while Cs2RbBi has the smallest κL of 0.45 Wm−1K−1, both of which are lower than the κL of traditional bismuth-based thermoelectric materials. The ultralow κL originates from the strong lattice anharmonicity. In addition, the coexistence of high dispersion and flat band edges leads to high thermoelectric power factor at optimal doping concentration. As a result, the largest thermoelectric figure of merit ZT values of 2.59 (4.19) at 300 (500) K were obtained for CsRb2Bi at optimal hole doping level. These findings suggest that CsxRb3−xBi compounds are superior for thermal management and thermoelectric applications.

Design of a low-cost, environment friendly perovskite solar cell with synergic effect of graphene oxide-based HTL and CH3NH3GeI3 as ETL

This research explores a novel, environment friendly perovskite solar cell (PSC) featuring a lead-free CH3NH3SnI3 absorber layer, capitalizing on tin’s analogous electronic configuration and chemical properties to lead. Tin-based perovskite exhibits similar optoelectronic features to lead-based perovskite, such as high absorption coefficient and long carrier diffusion length and tin’s higher abundance than lead renders it a cost-effective and promising alternative for PSCs. The proposed PSC employs an FTO/CH3NH3GeI3/CH3NH3SnI3/GO/C structure, incorporating graphene oxide (GO) as the hole transport layer (HTL) and CH3NH3GeI3 as the electron transport layer (ETL). Graphene oxide, renowned for its exceptional electrical conductivity and low processing costs, enables efficient hole transfer, while the use of CH3NH3GeI3 as ETL not only ensures seamless electron transfer due to its compatible crystallographic structure with CH3NH3SnI3 but also mitigates interface defects, making it a critical aspect of the design. Carbon is used as the back contact, providing a cost-effective option to increase sustainability. The absorber layer parameters, such as the thickness of the absorber layer and acceptor density, are optimized. The effects of defect density, interface defects of HTL/absorber and ETL/absorber, as well as series and shunt resistance, are also analyzed. By optimizing absorber layer parameters, the solar cell attains a power conversion efficiency (PCE) of 24.11% and a fill factor exceeding 85% within the visible light spectrum range, showcasing the potential for a high-performance, environment friendly, and cost-effective solar cell substitute. Device simulations were performed using the SCAPS-1D tool.

Fe2AlB2: A novel ferromagnetic material with superior electromagnetic wave absorption performance

MAB demonstrates remarkable potential for application as electromagnetic wave (EMW) absorbers due to its exceptional electrical conductivity, which closely resembles that of metals. Fe2AlB2 in the MAB phase also exhibits ferromagnetism (FM) at or near room temperature. Herein, in this study, Fe2AlB2 powders were successfully synthesized using a simple and efficient solid-liquid reaction method, and their EMW absorption properties were investigated. The synthesized Fe2AlB2 powders exhibit superior performance in EMW absorption, achieving a minimum reflection loss value of −47.39 dB at a frequency of 15.2 GHz, with an ultra-thin thickness of only 1.2 mm. Given their ease of preparation and strong EMW dissipation capabilities, Fe2AlB2 materials hold great promise as a new class of EMW absorption materials.

A Review on Progress, Challenges, and Prospects of Material Jetting of Copper and Tungsten.

Copper (Cu) and tungsten (W) possess exceptional electrical and thermal conductivity properties, making them suitable candidates for applications such as interconnects and thermal conductivity enhancements. Solution-based additive manufacturing (SBAM) offers unique advantages, including patterning capabilities, cost-effectiveness, and scalability among the various methods for manufacturing Cu and W-based films and structures. In particular, SBAM material jetting techniques, such as inkjet printing (IJP), direct ink writing (DIW), and aerosol jet printing (AJP), present a promising approach for design freedom, low material wastes, and versatility as either stand-alone printers or integrated with powder bed-based metal additive manufacturing (MAM). Thus, this review summarizes recent advancements in solution-processed Cu and W, focusing on IJP, DIW, and AJP techniques. The discussion encompasses general aspects, current status, challenges, and recent research highlights. Furthermore, this paper addresses integrating material jetting techniques with powder bed-based MAM to fabricate functional alloys and multi-material structures. Finally, the factors influencing large-scale fabrication and potential prospects in this area are explored.

Ultra‐Flyweight Cryogels of MXene/Graphene Oxide for Electromagnetic Interference Shielding

AbstractMXene and graphene cryogels have demonstrated excellent electromagnetic interference (EMI) shielding effectiveness due to their exceptional electrical conductivity, low density, and ability to dissipate electromagnetic waves through numerous internal interfaces. However, their synthesis demands costly reduction techniques and/or pre‐processing methods such as freeze‐casting to achieve high EMI shielding and mechanical performance. Furthermore, limited research has been conducted on optimizing the cryogel microstructures and porosity to enhance EMI shielding effectiveness while reducing materials consumption. Herein, a novel approach to produce ultra‐lightweight cryogels composed of Ti3C2Tx/graphene oxide (GO) displaying multiscale porosity is presented to enable high‐performance EMI shielding. This method uses controllable templating through the interfacial assembly of filamentous‐structured liquids that are readily converted into EMI cryogels. The obtained ultra‐flyweight cryogels (3–7 mg cm−3) exhibit outstanding specific EMI shielding effectiveness (33 000–50 000 dB cm2 g−1) while eliminating the need for chemical or thermal reduction. Furthermore, exceptional shielding is achieved when the Ti3C2Tx/GO cryogels are used as the backbone of conductive epoxy nanocomposites, yielding EMI shielding effectiveness of 31.7–51.4 dB at a low filler loading (0.3–0.7 wt%). Overall, a one‐of‐a‐kind EMI shielding system is introduced that is readily processed while affording scalability and performance.

The role of carbon materials in suppressing dendrite formation in lithium metal batteries

This review highlights several recent models of Li dendrite formation that have been proposed. Based on the comprehensive understanding and insight gained from these models, carbon materials have been developed to prevent the formation of Li dendrites by virtue of their exceptional electrical conductivity, electrochemical stability, mechanical properties and mouldability. A comprehensive review of the advantages of using carbon materials, such as graphene, carbon nanotubes, carbon fibers and hollow carbons, to deal with the formation of Li dendrites in recent years is provided. Finally, the limitations of carbon materials and future research directions for inhibiting Li dendrite formation are summarized as a reference for the development of new carbon materials for high-performance Li metal anodes.

Nanocomposite Foams of Polyurethane with Carbon Nanoparticles—Design and Competence towards Shape Memory, Electromagnetic Interference (EMI) Shielding, and Biomedical Fields

Polyurethane is a multipurpose polymer with indispensable physical characteristics and technical uses, such as films/coatings, fibers, and foams. The inclusion of nanoparticles in the polyurethane matrix has further enhanced the properties and potential of this important polymer. Research in this field has led to the design and exploration of polyurethane foams and polyurethane nanocomposite foams. This review article reflects vital aspects related to the fabrication, features, and applications of polyurethane nanocomposite foams. High-performance nanocellular polyurethanes have been produced using carbon nanoparticles such as graphene and carbon nanotubes. Enhancing the amounts of nanofillers led to overall improved nanocomposite foam features and performances. Subsequently, polyurethane nanocomposite foams showed exceptional morphology, electrical conductivity, mechanical strength, thermal stability, and other physical properties. Consequently, multifunctional applications of polyurethane nanocomposite foams have been observed in shape memory, electromagnetic interference shielding, and biomedical applications.