Electric Current Research Articles

Equivalence of magnetic flux and energy

Magnetic flux and energy equivalence is the principle that everything that has magnetic flux has an equivalent amount of energy, and vice versa. The main methods used: transformation of natural units, algebra, analogy. The equivalence of magnetic flux and energy, despite its widespread use in describing the principles of physics, has not yet been formulated. This paper presents the formula for this equivalence. This is done based on known measurement systems, parameters and principles of physics. Five examples (Stoney units, Planck units, standard gravitational parameter, Lorentz force, and Ampere force) of the algebraic representation of this principle show its universality. Five examples should justify the universality of the new principle and its use in physics and astrophysics. Using the equivalence of magnetic flux and energy, new physical units of mass and magnetic flux are proposed, each of which is suitable for measuring both mass and magnetic flux. Natural values of electric current and voltage, linear density of electric capacitance and inductance, linear density of magnetic flux, linear density of electric charge, as well as natural units of electric voltage and current, electrical resistance, magnetic flux, electrical capacitance and inductance are also described. The article presents the Einstein field equation (additional magnetic stress–energy–momentum tensor) and a standard astrophysical parameter for refining the orbits of celestial bodies.

A Multifunctional Anisotropic Patch Manufactured by Microfluidic Manipulation for the Repair of Infarcted Myocardium.

Engineered hydrogel patches have shown promising therapeutic effects in the treatment of myocardial infarction (MI), especially anisotropic patches that mimic the characteristics of native myocardium have attracted widespread attention. However, it remains a great challenge to develop cardiac patches with long-range and orderly electrical conduction based on an effective, mild, and rapid strategy. Here, a multifunctional anisotropic cardiac patch is presented based on microfluidic manipulation. The anisotropic alginate-gelatin methacrylate hydrogel patches are easily and rapidly prepared through microfluidic focusing, ion-photocrosslinking, and parallel packing processes. The fluid-based anisotropic realization process does not involve complex machining and strong field stimulation and is compatible with the loading of macromolecular biological agents. The anisotropic hydrogel patch can mimic the anisotropy of the myocardium and guide the directional polarization of cardiomyocytes. In animal model experiments, it also exhibits significant effects in inhibiting ventricular remodeling, fibrosis, and enhancing cardiac function recovery after MI. These comprehensive features make the multifunctional hydrogel patch a promising candidate for cardiac tissue repair and future provide a new paradigm for expanding microfluidic technology to solve tissue engineering challenges.

Characterization of Chlorophyll Based Dye-Sensitized Solar Cell using General-Purpose Photovoltaic Device Model

In dye-sensitized solar cells (DSSCs), light is absorbed by the sensitized dye. When light strikes the dye molecule, it absorbs photons and becomes excited to a higher energy state. This excited state allows the dye molecule to inject an electron into the conduction band of the semiconductor, generating an electric current. The selection of dye properties is very significant, as it can help to improve the performance of DSSCs. However, achieving an identical output current-voltage characteristic from the same batch of plants or fruits used as dyes is very difficult. Furthermore, improving the electrical performance, such as short-circuit current density and efficiency, of fabricated dye-sensitized solar cells is critical, as many experimental factors need to be considered. Therefore, to minimize the extra use of material resources due to the risk of unsuccessful fabrications and to obtain better performance ideally, conducting simulation-based studies is important to optimize the performance of DSSCs. The free software General-Purpose Photovoltaic Device Model (GPVDM) is a promising and interesting tool due to its free license and easy accessibility through a graphical interface for simulating optoelectronic devices, including OLEDs, OFETs, and various types of solar cells. This paper considers GPVDM, a 3-D photovoltaic device model, to simulate the proposed structure with different samples of chlorophyll dye for DSSC performance. The paper aims to characterize the high current density-voltage (J-V) of chlorophyll-based DSSCs and identify suitable photovoltaic simulation software for running simulations of chlorophyll-based DSSCs. Finally, the outcomes are compared with experimental data reported in various literature sources. The results show an enhanced short-circuit current density (Jsc) of 0.3556 mA cm-2 for Cordyline fruticose leaves (Chl E), which is the highest among the other dyes tested. The value of simulated short-circuit current density (Jsc) is slightly different from the experimented result Jsc reported in the published paper. In conclusion, GPVDM can be considered suitable for modeling DSSCs.

Coupling effects of micro/nano-scale surface modification and electric current application on fouling resistance and heat transfer

The principle of saving energy and converting waste heat into valuable resources is a core concept. Heat exchange systems are significantly compromised by microbial fouling, which impedes heat transfer and increases energy consumption. This study investigated the coupling effects of micro/nano-scale surface modifications and the application of electric currents as a novel approach to inhibit microbial fouling. Smooth copper surface, electrochemical deposition (ECD) surface, and Nickel-Phosphorus-Polytetrafluoroethylene (Ni-P-PTFE) modified surface were tested and compared. Firstly, we analyzed the average heat transfer coefficient under clean conditions, taking into account different surface characteristics. Then, we employed a series of fouling experiments to evaluate the anti-biofouling performance of smooth copper surfaces, ECD surfaces, and Ni-P-PTFE surfaces. The assessment involved flow cytometry, Scanning Electron Microscopy (SEM) and measurements of thermal resistance. Finally, we investigated the effect of external electric current on microbial fouling mitigation. Results show that the ECD surface exhibited an enhanced heat transfer and a poor fouling resistance, while the Ni-P-PTFE surface demonstrated an excellent fouling resistance and a minimal increase in thermal resistance. The application of a low direct current density at 0.51 mA/cm² significantly reduced microbial viability on all surfaces. A higher electric current can further inhibit microbial adhesion and proliferation, enhancing the anti-fouling capability of the surfaces. Compared to surfaces without electric current, the smooth copper surface, ECD, and Ni-P-PTFE surfaces at 5.1 mA/cm² displayed a reduction in thermal resistance by 45.7%, 36.8%, and 38.1%, respectively. At 51 mA/cm², the reduction in thermal resistance for smooth copper surface, ECD, and Ni-P-PTFE surfaces was 75.7%, 78.2%, and 57.1%, respectively. This comprehensive study has validated the potential of combining micro/nano-scale surface modifications with electric current application as an effective strategy for enhancing heat transfer efficiency and anti-fouling properties of heat exchange systems.

Nanosheet-interwoven structures and ion-electron decoupling storage enable Fe1-xS fast ion transport in Li+/Na+/K+ batteries

Fe1-xS, known for its high theoretical capacity, abundant resources, and intrinsic safety, has become a focal point as a universal anode for Li+/Na+/K+ batteries. However, its fast-charging capability is unsatisfactory due to sluggish ion transport rate and low electrical conductivity. Furthermore, its Li+/Na+/K+ storage mechanisms are still unclear. Here, we fabricate a single-crystal Fe1-xS/N-doped carbon composite nanosheet interwoven structure, in which N-doped carbon layers onto surface of Fe1-xS nanosheets ameliorate the electrical conduction and the interwoven nanosheets form open pore channels that favor permeation of electrolytes to boost ion transport. In-situ magnetometry reveals that ion-electron decoupling storage and transport occur in two-phase composites of Fe/Li2S, Fe/Na2S, and Fe/K2S, in which Fe phase stores and transports electrons and sulfide phase stores and transports ions in a space-charge form, resulting in extra ion storage and fast ion transport. Consequently, the nanosheet interwoven structure delivers high capacities (1320.1/652.2/350.6 mAh g−1), outstanding fast-charging performances (679.6/295.4/106.4 mAh g−1 at 20 A g−1), and long cycling life over 5000 cycles as Li+/Na+/K+ battery anodes, respectively

Coral reefs‐like shape AgI/polypyrrole nanocomposite through the intercalation of iodide ions in the network for optoelectronic applications

AbstractA promising optoelectronic device for light sensing in both the UV and Vis regions is fabricated. This device consists of a nanocomposite resembling coral reefs, termed AgI/polypyrrole‐iodide (AgI/Ppy‐I). The resulting nanocomposite exhibits a hierarchical structure wherein larger particles, comprising smaller particles ~45 nm and an optical bandgap measuring 2.4 eV, form a coral reef‐like morphology. The sensitivity estimation of this constructed optoelectronic device relies on evaluating the current density (Jph) values. Under illumination, a remarkable augmentation in current density (Jph = 0.46 mA cm−2) with a promising value compared to the dark condition's 0.12 mA cm−2. The optical characteristics of this nanocomposite make it highly conducive to efficient UV–Vis light sensing. The values of D (detectivity), reflecting the device's sensitivity, are notably high at 4 × 108 and 3.82 × 108 Jones in the UV and Vis regions, correspondingly. The potential of this photodetector is reinforced by the computed R‐values, which denote the device's responsivity. With values of 1.8 and 1.72 mA W−1 across these two optical regions, correspondingly, it showcases the nanocomposite's effectiveness in transforming incident light into electrical current. Moreover, the appeal of this photodetector extends beyond its performance characteristics. Its cost‐effectiveness, eco‐friendliness, straightforward preparation methodology, scalability for mass production, and high stability collectively. The versatility of this material, coupled with its advantageous attributes, opens avenues for its widespread application, catering to the diverse needs of industries and contributing to the accessibility of efficient optoelectronic devices for a broader audience.

Theory for electrodiffusional wall shear stress measurement by directionally sensitive twin semicircular probe

This study investigates the theoretical aspects of mass transport at the surface of a twin semicircular electrodiffusion probe tailored to measure the magnitude and direction of near-wall fluid flows. A critical aspect of this research is the development of a theoretical framework that facilitates experimental measurements by analytically relating measured electric currents to the wall shear stress vector. Central to the study is the derivation of analytical expressions for the mass transfer coefficients of the front and rear segments of the probe, which are essential for quantifying near-wall hydrodynamics. Validation of these analytical relations is achieved through numerical solutions of the convection–diffusion equation, providing a robust confirmation of the underlying theory. A comprehensive procedure for experimental data processing is proposed, taking into account both frontal and reverse flow conditions across the probe. In addition, a sensitivity analysis of the twin semicircular probe is performed. This analysis focuses on the response of current ratios to changes in the flow direction, an aspect critical to understanding the operational performance of the probe. The results of this analysis are compared to the characteristics of two-segment strip probes, highlighting the distinct sensitivity nuances of the twin semicircular probe. Our findings provide insight into the optimal application of this probe in various fluid dynamics scenarios.

Structural and electronic transformations in TiO2 induced by electric current

In-situ diffuse neutron scattering experiments revealed that when electric current is passed through single crystals of rutile TiO2 under conditions conducive to flash sintering, it induces the formation of parallel planes of oxygen vacancies. Specifically, a current perpendicular to the c-axis generates planes normal to the (132) reciprocal lattice vector, whereas currents aligned with the c-axis form planes normal to the (132) and to the (225) vector. The concentration of defects increases with incresing current. The structural modifications are linked to the appearance of signatures of interacting Ti3+ moments in magnetic susceptibility, signifying a structural collapse around the vacancy planes. Electrical conductivity measurements of the modified material reveal several electronic transitions between semiconducting states (via a metal-like intermediate state) with the smallest gap being 27 meV. Pristine TiO2 can be restored by heating followed by slow cooling in air. Our work suggests a novel paradigm for achieving switching of electrical conductivity related to the flash phenomenon.

Influence of Sodium Ions and Carbon Black on the Formation and Structural Color of Photonic Balls by Silica Particles.

In this study, photonic balls─spherical aggregates of submicrometer-sized silica particles with uniform particle size─were investigated as structural colored materials. The structural color of these photonic balls is influenced by the ordered arrangement of the silica particles. The research focused on how the addition of electrolytes, specifically NaCl, affects the formation of photonic balls to achieve the desired structural color. Without NaCl, the photonic balls formed onion-shaped colloidal crystals. At NaCl concentrations above 0.006 mol/L, the particles aggregated into short-range ordered structures. When the concentration exceeded 0.05 mol/L, the aggregates lost their spherical shape. The study also explored the addition of carbon black (CB), a water-dispersible material due to its surface charge. The findings revealed that NaCl induced the phase separation between the charged silica particles and CB, resulting in Janus-shaped photonic balls─one side exhibiting structural color and the other side appearing black due to the presence of CB. Changing the silica particle size altered the hues of these Janus-shaped photonic balls, though they appeared uniformly colored to the naked eye. While this study did not specifically examine the applications of Janus-shaped photonic balls composed of silica particles and CB, CB is known for its ability to absorb near-infrared radiation and convert it into heat as well as its conductive properties. Silica, on the other hand, has a low thermal conductivity and acts as an electrical insulator. The structurally colored Janus-shaped photonic balls created in this study may serve as pigments in applications requiring anisotropic heat generation and electrical conduction. Additionally, the study's findings suggest the potential for creating various types of Janus-shaped photonic balls from materials with differing densities.

Analytical prediction of the formation factor for anisotropic mono-sized unconsolidated porous media

The rectangular Representative Unit Cell (RUC) models for mono-sized isotropic unconsolidated porous media have been extended to anisotropic media. Volume averaging was applied to Ohm's law in order to propose analytical expressions for the formation factor for electrical conduction in terms of the pore-scale linear dimensions. The formation factor, crucial for understanding electrical conduction in porous media, has significant applications in subsurface geophysics, petroleum reservoir characterization, and the durability assessment of construction materials. These analytical models provide valuable insights for optimizing the electrical properties of porous structures in various engineering fields, for example in mapping groundwater resources, differentiating oil-bearing zones in reservoirs, and predicting ion migration in concrete. Aspect ratios of the cell and solid dimensions have been introduced, and the formation factor expressed in terms thereof for five different arrays, i.e. a regular, a non-overlapping streamwisely fully staggered, an overlapping streamwisely fully staggered, a non-overlapping transversally fully staggered, and an overlapping transversally fully staggered array. The Laplace equation has furthermore been solved numerically for two-dimensional versions of the different arrays and the formation factor computed for several values of the aspect ratios. The proposed analytical models have been validated against the generated numerical data and compared to experimental and numerical data obtained from the literature. The proposed models have also been adapted to include a percolation threshold porosity in order to improve the model predictions for very low porosity media.

Analog and digital resistive switching in W/TiO2/ITO devices: the impact of crystallinity and Indium diffusion

The resistance-switching memristor with capabilities of information storage and brain-inspired computing has prime importance in recent research. In this study, the impact of crystallinity and Indium diffusion on the existence of analog and digital resistive switching in a W/TiO2/ITO device has been reported. The memristor devices are fabricated by depositing titania films by sol–gel and spin-coating techniques. The films annealed at 250 °C and 400 °C were characterized using x-ray diffraction, Raman spectroscopy, scanning electron microscopy, and x-ray photoelectron spectroscopy (XPS). The characteristic anatase phase started appearing after annealing at 400 °C, whereas the 250 °C annealed sample was in the amorphous state. The electrical characterization revealed significant differences in the switching characteristics of amorphous and crystalline samples, especially in the switching interface, compliance properties, and current conduction mechanism. The grain boundary assisted oxygen vacancy migration, and the diffusion of indium ions from the ITO bottom electrode helped the crystalline sample to show highly stable and reproducible resistive switching compared to amorphous film. The XPS studies confirmed the indium ion diffusion in the crystalline sample. The oxygen vacancy-induced barrier modulation and conductive filament formation caused characteristic switching in amorphous and crystalline samples, respectively. Schottky emission in the amorphous film and SCLC mechanism in the crystalline film confirmed the experimental results. This study provides a distinctive viewpoint and an innovative strategy for developing multifunctional resistive switching devices.

Exploring the Non-Invasive Methods of Brain- Computer Interface: A Comprehensive Review of their Advances and Applications

The brain-computer interface technology allows the human brain to control external devices directly without using the brain’s output channels or peripheral nerves. It helps individuals with motor impairments to use mechanical and external devices to communicate with the outside world. Non-invasive BCIs allow communication between the human brain and external devices without the need for surgeries or invasive procedures. Methods like EEG, MEG, fMRI, and fNIRS are used. EEG enables the acquisition of electrical activity along the scalp by measuring voltage fluctuations and neurotransmission activity in the brain. The electrodes are attached to a cap-like device and are placed on the scalp to record the electrical current generated by the brain. Unlike MEG, which necessitates specially constructed rooms, EEG is portable. Lab-grade EEG is expensive but cheaper than other forms of BCI. MEG uses magnetometers to measure magnetic fields produced by electric currents occurring naturally in the brain. MEG is better than EEG at measuring high-frequency activity. MEG signals are less distorted by the skull layer. FMRI records blood oxygen level-dependent (BOLD) signals with high spatial resolution across the entire brain. It does this by tracking the hemodynamic response, which is the increase in blood flow to active brain areas. It does this using the principle of nuclear magnetic resonance, where hydrogen atoms in water molecules in the blood emit signals when subjected to a strong magnetic field. It has an advantage over EEG due to its superior spatial specificity and resolution. FNIRS measures the blood flow and oxygenation in the blood associated with neural activity. It gains insight into the brain's hemodynamic response, which is essential for understanding neural functioning during BCI tasks.

Unlocking the potential of low-melting-point alloys integrated extrusion additive manufacturing: insights into mechanical behavior, energy absorption, and electrical conductivity

AbstractAdditive manufacturing is a commonly used manufacturing method in complex part fabrication, instant assemblies, part consolidation, mass customization and personalization, on-demand manufacturing, lightweight, and topological optimization due to its advantage of lower costs, flexibility to learn and use, reduced raw material wastage, digital design integration, high efficiency, environmental-friendliness. However, the current metal 3D printing, which is mainly fabricated layer by layer using laser, is expensive to manufacture metal parts. Therefore, in this paper, a low-cost high-quality metal manufacturing process called low-melting-point alloys (LMPAs) integrated extrusion additive manufacturing will be examined. This manufacturing process can fabricate complex metal structures and integrated circuits with simple fused deposition modeling, which is a cost-effective method for producing these objects. LMPAs with different melting points are used for performance comparison to find out the optimized mechanical behavior, energy absorption properties, and electrical conductivity. Our investigation into LMPAs integrated extrusion additive manufacturing has revealed significant findings. Tensile tests conducted on LMPAs with varying melting points have illuminated distinct mechanical behaviors. Notably, lower melting points contribute to increased ductility but reduced stiffness, while higher melting points result in greater stiffness but diminished ductility. These results emphasize the importance of tailoring LMPA selection based on specific application requirements. Furthermore, our examination of lattice and triply periodic minimal surface structures has demonstrated consistent energy absorption properties across different manufacturing temperatures, highlighting the adaptability and versatility of LMPAs for energy absorption applications. Additionally, our electrical conductivity assessments have shown that LMPAs with melting points of $${{47}^{\circ }C}$$ 47 ∘ C and $${{120}^{\circ }}\hbox {C}$$ 120 ∘ C exhibit higher electrical conductivity, making them suitable for applications requiring good electrical conduction properties. These findings collectively underscore the significance of LMPAs in additive manufacturing, offering valuable insights for material selection and applications in various domains.

Influence of MXene Interlayer Spacing on the Interaction with Microwave Radiation

AbstractThe origin of MXene's excellent electromagnetic shielding performance is not fully understood. MXene films, despite being inhomogeneous at the nanometer scale, are often treated as if they are compared to bulk conductors. It is reasonable to wonder if the treatment of MXene as a homogeneous material remains valid at very small film thickness and if it depends on the interlayer spacing. The goal of the present work is to test if the homogeneous material model is applicable to nanometer‐thin Ti3C2Tx MXene films and, if so, to investigate how the model parameters may depend on variations in MXene interlayer spacings. MXene films containing flakes with interlayer spacing between 1.9 and 5.5 Å have been prepared using various intercalating agents. It is shown that modeling the films as being homogeneous agrees with experimental tests in the microwave frequency range. Microwave conductivity and dielectric constant parameters are estimated for the homogeneous film model by fitting measured results. The direct current (DC) conductivity matches the estimated microwave conductivity on the order of magnitude. A highly effective dielectric constant provides a good fit for the lower conductivity MXene films. Optical absorption agrees with the homogeneous material model of thin films as well.

Sandwich-structured polymer dielectrics exhibiting significantly improved capacitive performance at high temperatures by roll-to-roll physical vapor deposition

Electrostatic capacitors with ultrahigh power density are the key components in modern electrical and electronic systems. Polymers are preferred dielectrics for high-voltage electrostatic capacitors, however, unable to meet the ever-growing high-temperature requirements in emerging applications, such as electric vehicles, and photovoltaic power generation. In this work, sandwich-structured Polyphenylene sulfide (PPS) films with Al2O3 as the coating layer have been prepared by using roll-to-roll magnetron sputtering. The incorporation of Al2O3 coating layers enhances the potential barrier height at the electrode/dielectric interface, thereby impeding charge injection from electrodes and suppressing high-temperature electrical conduction. Consequently, the sandwich-structured PPS films demonstrate significantly improved breakdown strengths and enhanced capacitive performance at elevated temperatures compared to neat PPS films. The roll-to-roll magnetron sputtering process employed in fabricating these sandwich-structured dielectric films is highly compatible with large-scale capacitor film production. Thus, sandwich-structured PPS films hold promise in addressing the challenge of scalable fabrication of high-performance, high-quality polymer films required for high-temperature capacitive energy storage.

Drude’s lesser known error of a factor of two and Lorentz’s correction

As is well known, Paul Drude put forward the very first quantitative theory of electrical conduction in metals in 1900. He could successfully account for the Wiedemann–Franz law which states that the ratio of thermal to electrical conductivity divided by temperature is a constant called the Lorenz number. As it turns out, in Drude’s derivation there is a lucky cancellation of two errors. Drude’s underestimatation (by an order of 100) of the value of square of the average electron velocity compensated for his overestimatation of the electronic heat capacity (by the same order of 100). This compensation or cancellation of two errors lead to a value of the Lorenz number very close to its experimental value; which is well known. There is another error of a factor of two which Drude made when he calculated two different relaxation times for heat conductivity and electrical conductivity; in this article we highlight how and why this error occurred in Drude’s derivation and how it was removed 5 years later (in 1905) by Hendrik Lorentz when he used the Boltzmann equation and a single relaxation time. This article is of pedagogical value and may be useful to undergraduate/graduate students learning solid state physics.

Features of spectral characteristics of phenyl-containing vanadium (III) β-diketonates

Tris-dibenzoylmethanate ([V(dbm)3 ]) and tris-benzoylacetonate vanadium ([V(bac)3 ]) were obtained by electrochemical synthesis. The composition of chelates was determined using elemental analysis and IR spectral data. It was shown that the formation of a quasi-aromatic metallocycle, the main structural element of chelate, occurred as a result of electrolysis. At the same time, the batachromic shift of absorption bands of carbonyl groups was more than 100 cm–1. The overwhelming majority of absorption bands in the IR spectra of both compounds had mixed nature. For ([V(dbm)3 ] the characteristic of absorption bands did not exceed 13.5 %, and for [V(bac)3 ] – 10.3 %. The peripheral groups of ligands (phenyl and methyl) did not undergo transformation when influenced by electric current.

Effect of Electrodeposition Time on the Growth Rate of Carbon Nanotubes (CNTs)

Carbon Nanotubes (CNTs) are nano-sized carbon that resembles tubes and has the potential to be used in various aspects of applications. Some of the CNT carbon capture methods include arc discharge, lasser ablation, CVD and electrodeposition. The advantage of the electrodeposition method is that the production cost is cheap and the preparation is easy. Electrodeposition is the precipitation of substances by using a direct electric current, with CO2 as the reactant. Factors that affect the growth rate of CNT are voltage, temperature, carbon source, electrode and time. The variation of the electorative time used was 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes. The data collection process begins by shaping and measuring the weight of the electrode (Ni) with a diameter of 2 cm CNT deposition area. measuring the weight and melting Li2CO3 at a temperature of 750. then the CO2 flow rate setting, voltage setting 5V and time setting were then characterized by SEM-EDX and XRD. The results of the study showed that the optimal time obtained with a time of 120 minutes, the resulting CNT deposition rate was 1,618 g cm-2 h-1. Then based on the characterization of XRD and SEM, it shows that the longer the electrodeposition time, the less impurities are contained in the results obtained.

Mass transport driving forces under electric current in the liquid Sn-Zn system

Significant effects of electric currents on mass transport in liquid metals have been observed for long, but the origin of the corresponding driving forces remains unclear in the literature. Without current, two driving forces induce mass transport in liquid metals. (i) A chemical force, coming from concentration gradients. In that case, mass transport occurs by diffusion. (ii) A physical force, resulting from density gradients thermally and/or chemically induced. Here, mass transport occurs by thermal and/or solutal convection. Under electric currents, these driving forces are modified, either by electrostatic or magnetic forces, the corresponding mechanisms being referred to as electroconvection and magnetoconvection, respectively. However, these mechanisms cannot easily be distinguished from each other, leading to confusion in literature. Here, it has been shown that, in the liquid Sn-Zn system, the driving force induced by 500–1000 A/cm2 electric current densities is magnetic rather than electrostatic, the mechanism being therefore magnetoconvection.

Impacts of Curing-Induced Phase Segregation in Silicon Nanoparticle-Based Electrodes

We report the investigation of silicon nanoparticle composite anodes for Li-ion batteries, using a combination of two nm-scale atomic force microscopy-based techniques: scanning spreading resistance microscopy for electrical conduction mapping and contact resonance and force volume for elastic modulus mapping, along with scanning electron microscopy-based energy dispersion spectroscopy, nanoindentation, and electrochemical analysis. Thermally curing the composite anode—made of polyethylene oxide-treated Si nanoparticles, carbon black, and polyimide binder—reportedly improves the anode electrochemical performance significantly. This work demonstrates phase segregation resulting from thermal curing, where alternating bands of carbon and silicon active material are observed. This electrode morphology is retained after extensive cycling, where the electrical conduction of the carbon-rich bands remains relatively unchanged, but the mechanical modulus of the bands decreases distinctly. These electrical and mechanical factors may contribute to performance improvement, with carbon bands serving as a mechanical buffer for Si deformation and providing electrical conduction pathways. This work motivates future efforts to engineer similar morphologies for mitigating capacity loss in silicon electrodes.