Conductivity Enhancement Research Articles

Activating Organic Electrode for Zinc Batteries via Adjusting Solvation Structure of Zn Ions.

Zinc-organic batteries, combining the low cost and high capacity of Zn anodes with the tunable and sustainable properties of organic cathodes, have garnered significant attention. Herein, we present a zinc-organic battery featuring a poly(benzoquinonyl sulfide) (PBQS) cathode, a Zn anode, and anN,N-dimethylformamide (DMF)-based electrolyte, which delivers a high capacity (200 mAh g-1), excellent rate capability, and an ultra-long cycle life (10,000 cycles) when tested with a low PBQS loading (2 mg cm-2). The charge storage mechanism in the PBQS cathode involves solvated Zn2+ adsorption and consequent Zn2+ coordination with PBQS companied by de-solvation process, as confirmed by in-situ FT-IR analysis. However, sluggish Zn2+ de-solvation leads to a loss of Zn2+ coordination capacity when tested with higher PBQS loading (8 mg cm-2) even at a low current density of 0.2 A g-1. Remarkably, the addition of 2% H2O to the DMF electrolyte incorporates 0.24 H2O into the primary solvation sheath of Zn2+, significantly facilitating the de-solvation process. As a result, the PBQS cathode (8 mg cm-2) retains its Zn2+ storage capacity when using the modified electrolyte. This approach offers a new strategy for improving the rate performance of organic electrodes, complementing existing conductivity enhancements.

Activating Organic Electrode for Zinc Batteries via Adjusting Solvation Structure of Zn Ions

Zinc‐organic batteries, combining the low cost and high capacity of Zn anodes with the tunable and sustainable properties of organic cathodes, have garnered significant attention. Herein, we present a zinc‐organic battery featuring a poly(benzoquinonyl sulfide) (PBQS) cathode, a Zn anode, and an N,N‐dimethylformamide (DMF)‐based electrolyte, which delivers a high capacity (200 mAh g‐1), excellent rate capability, and an ultra‐long cycle life (10,000 cycles) when tested with a low PBQS loading (2 mg cm‐2). The charge storage mechanism in the PBQS cathode involves solvated Zn2+ adsorption and consequent Zn2+ coordination with PBQS companied by de‐solvation process, as confirmed by in‐situ FT‐IR analysis. However, sluggish Zn2+ de‐solvation leads to a loss of Zn2+ coordination capacity when tested with higher PBQS loading (8 mg cm‐2) even at a low current density of 0.2 A g‐1. Remarkably, the addition of 2% H2O to the DMF electrolyte incorporates 0.24 H2O into the primary solvation sheath of Zn2+, significantly facilitating the de‐solvation process. As a result, the PBQS cathode (8 mg cm‐2) retains its Zn2+ storage capacity when using the modified electrolyte. This approach offers a new strategy for improving the rate performance of organic electrodes, complementing existing conductivity enhancements.

Compatibility Study of Synthesized Materials for Thermal Transport in Thermoelectric Power Generation

This study investigates the compatibility of synthesized materials for optimized thermal transport within thermoelectric modules. Experimental procedures involved the synthesis of candidate materials followed by characterization using techniques such as scanning electron microscopy, and thermal conductivity measurements. The research employs electrodeposition of HoSbxTex on the synthesized materials using AAo as a template in the electrolyte composed of 2mm TeO2, 2.5mm Bi(No3)3, 0.33mm SeO2, and 0.2m HNO3. Compatibility assessments were conducted within simulated thermoelectric modules to evaluate the materials’ performance under realistic operating conditions. The findings reveal crucial insights into the interplay between material properties and thermal transport mechanisms, guiding the selection and optimization of materials for enhanced thermoelectric power generation. Moreover, this study underscores the importance of tailored material design to achieve synergistic enhancements in both thermal and electrical conductivity, thereby advancing the efficiency and viability of thermoelectric energy conversion technologies. This research contributes to the ongoing efforts to enhance thermoelectric power generation and supports the global transition to sustainable energy systems.

Research on the enhancement of densification and electrical conductivity of silver-coated copper conductive films via oxidation–reduction sintering method

Research on the enhancement of densification and electrical conductivity of silver-coated copper conductive films via oxidation–reduction sintering method

Effective control of conductivity in lutetium orthoferrite with cobalt doping measured by terahertz time-domain spectroscopy

The effective control of conductivity in LuFeO3 (LFO) with Co3+ doping is explored by terahertz (THz) time-domain spectroscopy. It is demonstrated that the conductivity of 5% Co-doped LFO (LFO:Co 5%) is lower than that of LFO, while that of 15% Co-doped LFO (LFO:Co 15%) is significantly higher than LFO. Furthermore, LFO exhibits two lattice vibration peaks at 0.58 and 1.61 THz, LFO:Co 5% shows only one lattice vibration peak at 1.61 THz, while no distinct vibration peak is observed in LFO:Co 15%. The disappearance of lattice vibration at 0.58 THz is attributed to the shortened Fe (Co)-O bond length resulting from Co3+ doping, thus suppressing magnetic resonance effect of Fe3+. With 15% Co3+ doping, structural stability is enhanced, and the asymmetric vibration of Lu3+ at surface/interface/boundary is suppressed, resulting in the disappearance of vibration peak at 1.61 THz. The conductivity of LFO:Co 5% is lower than that of LFO, mainly because the lattice vibration at 1.61 THz and oxygen vacancy defects introduced by doping jointly increase the degree of carrier back-scattering, which decreases carrier movement, while the enhancement of conductivity by electronegativity at 5% Co3+ doping is very limited. The significantly higher conductivity of LFO:Co 15% compared to LFO is due to the obvious increase in overall electronegativity and suppression of lattice vibration by 15% Co3+ doping, thereby improving carrier mobility. The insights of this investigation provide important experimental data and theoretical basis for design and production of high-conductivity and stable solid oxide fuel cells cathode.

Evaluation of stability, optical properties, and thermal performance of innovative TiO2/FeVO4 Ethylene Glycol hybrid nanofluids

Abstract The effectiveness of direct absorption solar collectors (DASCs) is limited due to the low photothermal conversion efficiency and poor heat transfer qualities of traditional fluids. One potential solution to address this problem is the development of innovative technologies to enhance the solar absorption ability and thermal conductivity of conventional fluids. New generation nanofluids where nanosized particles are dispersed in base fluids like water or ethylene glycol (EG) have attracted interest within diverse solar technologies owing to their superior optical and thermal properties. This study presents a novel TiO2/FeVO4/Ethylene glycol (TFV/EG) nanofluid which exhibits significant solar absorption and thermal stability characteristics. A thorough characterization of the samples was conducted utilizing X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, High-Resolution Transmission Electron Microscopy (HRTEM), nitrogen adsorption-desorption isotherms and Thermogravimetric Analysis (TGA). The stability, optical and rheological characteristics of TFV nanofluids were also examined. The study’s outcomes indicated that the integration of TFV nanoparticles into ethylene glycol (EG) markedly improved its optical absorption, especially at a concentration of 0.8 g/l TFV, which demonstrated robust absorption in the UV-visible light spectrum. Long-term stability assessments indicated sedimentation for all TFV concentrations following 65 days. A substantial 270% enhancement in thermal conductivity in comparison to EG base fluid was noted at 0.8 g/l TFV reaching 0.83 W·m⁻¹·K⁻¹. All nanofluids exhibited shear-thinning behavior, a hallmark of non-Newtonian fluids. The suggested TFV/EG represents a notable category of nanofluids that exhibited improved thermal performance and stability, rendering them very advantageous for efficient DASCs.

Liquid Metals for Advanced Batteries: Recent Progress and Future Perspective

ABSTRACTThe shift toward sustainable energy has increased the demand for efficient energy storage systems to complement renewable sources like solar and wind. While lithium‐ion batteries dominate the market, challenges such as safety concerns and limited energy density drive the search for new solutions. Liquid metals (LMs) have emerged as promising materials for advanced batteries due to their unique properties, including low melting points, high electrical conductivity, tunable surface tension, and strong alloying tendency. Enabled by the unique properties of LMs, four key scientific functions of LMs in batteries are highlighted: active materials, self‐healing, interface stabilization, and conductivity enhancement. These applications can improve battery performance, safety, and lifespan. This review also discusses current challenges and future opportunities for using LMs in next‐generation energy storage systems. image

Optimizing Magnetic, Mechanical, and Electrical Properties of Cobalt-Substituted Zinc Chromite Spinel via Microwave-Hydrothermal Synthesis

Abstract Using the microwave-hydrothermal technique, researchers synthesized a cobalt-substituted zinc chromite spinel structure with the formula Zn1 − xCoxCr2O4 (x = 0.0, 0.25, 0.50, 0.75, 1.0). The resulting powder underwent analysis via X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) to determine the ideal conditions for eliminating organic components from the fired pellet. After establishing the optimal initial calcination temperature, all powder samples were calcined at 600 °C, then compressed and fired at 1300, 1400, 1500, and 1600 °C. The fired pellets were then examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Additionally, researchers evaluated the pellets’ physical, electrical, dielectric, magnetic, and mechanical properties. The findings indicated that 1600 °C was the optimal firing temperature for the pellets. The apparent porosity decreased, and the bulk density increased with increasing Co content and firing temperature. Enhancements in magnetization, mechanical, and electrical conductivity, dielectric properties, and elastic moduli were observed by increasing the cobalt content. Porosity has a significant impact on mechanical properties. The mechanical properties were slightly reduced for zinc-rich pellets. The dielectric constant and the dielectric loss increased with increasing Co content at 1 MHz. In addition, the results show that the dielectric constant and dielectric loss factor decreased with increasing frequency, whereas the A.C. electrical conductivity increased with increasing frequency.

Transition Metal Based Spin-Tuned Charge Transfer in Single-Molecule Junctions.

Investigating the correlation between metal coordination and molecular conductivity in single-molecule systems is essential for advancing our knowledge of molecular electronics, particularly in the realm of spintronics. In the present study, we developed two complex wires utilizing the bipyridine ligand and two transition metal ions, Co2+ and Zn2+, aiming to study the impact of different spin characters on single-molecule charge transport properties. Single-molecule conductance was investigated using scanning tunnelling microscope breaking junctions (STM-BJ) technique and the underlying mechanism was analysed by density functional theory (DFT) calculations. We demonstrated that the conductance predominantly increases after inserting Zn2+, indicating a conducting channel has been constructed. In contrast, the conductance of the analogue coordinated with Co2+ does not change significantly, this can be explained by distinct disparities between spin-up and spin-down channels, in which destructive quantum interference in spin-down state counteracts the enhancement of molecular conductance. Our study establishes the groundwork for a systematic approach to the design, fabrication, and implementation of single-complex conductance explorations.

Thermally Conductive Shape-Stabilized Phase Change Materials Enabled by Paraffin Wax and Nanoporous Structural Expanded Graphite.

Paraffin wax (PW) has significant potential for spacecraft thermal management, but low thermal conductivity and leakage issues make it no longer sufficient for the requirements of evolving spacecraft thermal control systems. Although free-state expanded graphite (EG) as a thermal conductivity enhancer can ameliorate the above problems, it remains challenging to achieve higher thermal conductivity (K) (>8 W/(m·K)) at filler contents below 10 wt.% and to mitigate the leakage problem. Two preparations of thermally conductive shape-stabilized PW/EG composites, using the pressure-induced method and prefabricated skeleton method, were designed in this paper. The expanded graphite formed a nanoscale porous structure by different methods, which enhanced the capillary action between the graphite flake layers, improved the adsorption and encapsulation of EG, and alleviated the leakage problem. The thermal conductivity and the latent heat of the phase-change materials (PCM) prepared by the two methods mentioned above are 9.99 W/(m·K), 10.70 W/(m·K) and 240.06 J/g, 231.67 J/g, respectively, at EG loading by 10 wt.%, and the residual mass fraction was greater than 99% after 50 cycles of high and low temperature. In addition, due to the excellent thermal management capability of PW/EG, the operating temperature of electronic components can be stably maintained at 68-71 °C for about 15 min and the peak temperature can be reduced by at least 23 °C when the heating power of the electronic components is 10 w. These provide novel and cost-effective methods to further improve the management capability of spacecraft thermal control systems.

Anomalous increase in the thermal conductivity of water on the addition of liquid-exfoliated magnesium diboride sheets

The addition of MgB2 nanosheets into water, results in an enhancement of the thermal conductivity of the water to 25% at low volume fraction (ϕ). This observation claimed as anomalous when evaluated in the context of mean-field theory.

Novel ionic liquid-infused PVA-based anion exchange membranes boosting bioelectricity yield from microbial fuel cells.

The goal of this research is to develop and characterize low-cost NH4I doped polyvinyl alcohol (PVA)-4-ethyl-4-methylmorpholiniumbromide (ionic liquid) anion exchange membranes (AEM) and its application for membrane cathode assembly. Physical characterization like FTIR, POM, and XRD notified the functional groups, basic structure, and amorphosity of the produced membrane, and it was employed in single-chambered microbial fuel cells (sMFCs) as a separator. The membranes in terms of oxygen diffusion, proton conductivity, and ion exchange capabilities were evaluated. PVA-ionic liquid composite membrane had a greater volumetric power density (PD) with a rise in the ionic liquid concentration, owing to lower internal resistance and reduced biofouling. Ionic conductivity also reduces as loading increases over a certain level of concentration. The incorporation of ionic liquid into the membrane had a considerable impact on impedance minimization (an enhancement in anionic conductivity) and biofouling. When MFC was used with a PVA-ionic liquid-based membrane cathode assembly (MCA), the highest PD of 7.98W/m3 was attained which is better than other composite membranes. The MCA surface area boosted the power output. The PVA-ionic liquid composite membrane proved to be a viable alternative to the more costly commercially available MFC membrane. This paper's novelty lies in synthesizing ammonium iodide (NH4I) doped PVA-ionic liquid membrane and further utilizing it as a separator in MFC. Also, this study demonstrates the membrane's potential for enhancing MFC performance, establishing it as a viable alternative to expensive commercial membranes.

Nanoring interactions with bio-relevant molecule: A quantum chemical approach to C18 and B9N9 systems.

This study investigates the interaction of a synthetic bio-relevant molecule with C18 and B9N9 nanorings, exploring their potential applications in sensing and drug delivery. Employing Density Functional Theory (DFT) at the ωB97XD level with the 6-31G(d,p) basis set, we computed the adsorption and electronic properties of the resulting nanocomplexes. A total of ten distinct configurations were identified for the interactions, with adsorption energies ranging from -6.75 to -12.62kcal/mol for the C18@target molecule and -9.01 to -18.46kcal/mol for the B9N9@target molecule. Notably, alterations in the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) upon interaction suggest an enhancement in electrical conductivity. The effect of aqueous media was also examined, revealing an increase of approximately 2.0 Debye in the dipole moments of the most stable nanocomplexes. Additional analyses, including reduced density gradient (RDG), UV-Vis spectroscopy, and Quantum Theory of Atoms in Molecules (QTAIM), were conducted in both gas and aqueous phases. Our findings indicate that C18 and B9N9 nanorings exhibit significant promise as candidates for drug delivery and sensing applications, particularly due to their enhanced electronic properties upon interaction with the bio-relevant molecule.

Frontier fabrication of silicon-based anodes: Synergistic enhancement of structural integrity and conductivity

Frontier fabrication of silicon-based anodes: Synergistic enhancement of structural integrity and conductivity

Thermal conductivity enhancement in carbon black composite PCM for thermal energy storage

Abstract Phase Change Materials (PCMs) hold significant potential for developing next-generation energy storage technologies due to their cability to reversibly store and release thermal energy with energy density through isothermal phase transition. This work explores improving the heat conduction and thermophysical properties of PCMs, tackling issues such as low thermal conductivity, which can result in longer charge and discharge times. We demonstrated that the thermal conductivity of lauric acid-based PCM (LA-PCM) loaded with carbon black nanoparticles (CBNP) can be significantly enhanced. The PCM loading with 5 wt.% CBNP nanoparticles had an approximately 50% enhancement in thermal conductivity. Additionally, 25 wt.% of turmeric powder (Curcuma) significantly improved shape stability and stopped material leakage across the solid-liquid phase transition of composite PCM. The enhanced thermal conductivity of the composite PCM can be attributed to the development of interconnected percolation networks of CBNP particles with low thermal resistance during the freezing (solidification) of the PCM that provides a more effective phonon transport path. Sustainable energy materials (composite PCMs) with better thermal properties, shape stability, and low cast would be beneficial for practical application suitability and effective energy storage applications.

Bulk thermally conductive polyethylene as a thermal interface material.

As the demand for high-power-density microelectronics rises, overheating becomes the bottleneck that limits device performance. In particular, the heterogeneous integration architecture can magnify the importance of heat dissipation and necessitate electrical insulation between critical junctions to prevent dielectric breakdown. Consequently, there is an urgent need for thermal interface materials (TIMs) with high thermal conductivity and electrical insulation to address this challenge. In this work, we synthesized thermally conductive polyethylene (PE) bars with vertically aligned polymer chains via a solid-state drawing technique to achieve a thermal conductivity of 13.5 W m-1 K-1 with a coverage area of 2.16 mm2. We utilized wide-angle X-ray scattering to elucidate the molecular structural changes that led to this thermal conductivity enhancement. Furthermore, we conducted a device-cooling experiment and showed a 39% hot spot temperature reduction compared to a commercial ceramic-filled silicone thermal pad under a heating power of 3.6 W. Thus, this bulk-scale thermally conductive PE bar with nanoscale structural refinement demonstrated superior cooling performance, offering potential as an advanced thermal interface material for thermal management in microelectronics.

Structure characteristics and thermal conductivity enhancement of binary eutectic adsorbed into two modified biomass char under vacuum conditions

Structure characteristics and thermal conductivity enhancement of binary eutectic adsorbed into two modified biomass char under vacuum conditions

Utilizing biomass-derived activated carbon hybrids for enhanced thermal conductivity and latent heat storage in form-stabilized composite PCMs

ABSTRACT In this study, the focus was on developing multifunctional organic form-stabilized composite phase change materials (PCMs) to efficiently manage thermal energy and promote sustainable energy utilization. The novel composite PCMs were designed and synthesized by incorporating Methyl stearate (MtS) as the PCM with pristine activated carbon derived from coconut shells (CAC) and thermally enhanced CAC@Graphene nanoplatelets (GnP) hybrid matrices. Particularly, the combination of CAC90@GnP10/MtS allowed the composite PCM to exhibit excellent thermophysical responses, capitalizing on the unique properties and synergistic effects of each component. The resulting composite PCM from this combination demonstrated remarkable performance, with a high loading ratio of 70% and a latent heat of 160.87 J/g, which is 27.52% higher than that of the pristine CAC-supported PCM. The test results indicated that the chemical and crystal structure of MtS remained unaffected after the composite formation. The thermal conductivity of CAC90@GnP10/MtS was found to be 102.85% higher than CAC/MtS and 195.83% higher than MtS alone. The enhancement in thermal conductivity was further validated through observed reductions in melting and solidification times, as well as analysis using infrared thermal imaging. In conclusion, the development of these intelligent, multifunctional composite PCMs, which utilize CAC@GnP hybrids as supporter scaffolds and thermal conductivity enhancers for MtS, holds great promise for effective sustainable energy usage and thermal energy management systems in various fields like waste heat utilization, energy-saving buildings, constant temperature protection, thermal management of electronic devices, aerospace industry, textiles, automotive, and renewable energy systems.

Investigation of Solid Electrolyte Interphase Regarding Extra Capacity in Fe‐Fe3C as a Superior Sodium‐Ion Anode Material

AbstractSodium‐ion batteries (SIBs) offer promising advantages over lithium‐ion batteries (LIBs) due to sodium's abundance and lower cost. However, challenges like thick solid electrolyte interphase (SEI) layers and the larger radius of sodium (1.02 Å vs. 0.76 Å for lithium) make graphite, the most common LIB anode, unsuitable for SIBs. To realize the maximum potential of carbon anode for SIBs, one of the main strategies is to fabricate carbon materials with tailored microstructures and to enhance redox reactivity by incorporating catalytic metals. In this work, the Fe‐Fe3C nanoparticles embedded in worm‐like graphitic carbon (Fe‐Fe3C@GC) were synthesized by a simple chemical vapor deposition. This hybrid structure promotes the catalytic activity to achieve additional capacities through the reversible SEI layer formation, in detail, by the reversible interconversion of ester and ether derivatives as well as conductivity enhancement. Furthermore, in situ formed Fe2O3 from Fe(0) contributed extra capacity. The Fe‐Fe3C@GC showed a large reversible discharge capacity of 376.2 mAh g−1 with a fading rate of 0.013% per cycle after 1000 cycles at a current density of 50 mA g−1. A full cell coupled with an FeOF cathode delivered a high energy density of 602.8 Wh kg−1.

Co3O4-RuO2/Ti3C2Tx MXene Electrocatalysts for Oxygen Evolution Reaction in Acidic and Alkaline Media.

MXene 2D materials and non-noble transition metal oxide nanoparticles have been proposed as novel pH-universal platformsfor oxygen evolution reaction (OER), owing to the enhancement of active site exposures and conductivity. Herein, Co3O4-RuO2 /Ti3C2Tx/carbon cloths (CRMC) were assembled in a facile way as an efficient OER platform through a hydrothermal process. The Co3O4-RuO2/Ti3C2Tx demonstrated prominent OER catalytic performance under acidic and alkaline conditions, which showed overpotential values of 195 and 247 mV at 10 mA cm-2 with Tafel slopes of 93 and 97 mVdec-1, respectively. The experimental results demonstrated that the electron transfer from Co3O4-RuO2 to Ti3C2Tx/carbon cloth played a remarkable role in promoting OER catalytic activity. Further OER characterization indicated that the enhanced multi-electron reaction kinetics are attributed to Co and Ru acting as the primary active places for O2 adsorption and activation, which facilitated the generation of *OOH intermediate.