Uniform Electric Field Research Articles

Achieving highly reversible regulation of zinc deposition through ultrafast in situ construction of multifunctional zinc anode interfaces

The zinc anode surface suffers from severe zinc dendrite growth and side reactions, such as hydrogen evolution, significantly diminishing its reversibility and cycle life. In this study, we have introduced and successfully implemented, for the first time, the ultrafast in-situ construction of a periodic semi-spherical multifunctional interfacial layer composed of copper nanoparticles (Cu|Zn) on the zinc anode surface. By optimizing the distribution of the electric field and Zn2+ concentration, we effectively mitigate the “Tip effect”, achieving highly reversible control over zinc deposition, and the in-situ construction process takes only 3 min. Theoretical calculations and COMSOL simulations demonstrate that the Cu|Zn anode exhibits high binding energy, a uniform electric field, and Zn2+ concentration distribution. Experimental results reveal that the Cu|Zn anode achieves exceptional long-term cyclic stability, exceeding 3200 h at 1 mA cm−2 and remaining cyclically stable for over 2000 h at 5 mA cm−2. Furthermore, in a full cell with MnO2@MXene as the cathode material, the Cu|Zn anode delivers a capacity of 282.1 mA h g−1 after 1400 cycles at 2 A g−1. This study holds significance for the rational design of high-stability and reversible interface layers, promoting their practical application in aqueous zinc-ion batteries (AZBs).

High-Order Nonlinear Electrophoresis in a Nematic Liquid Crystal.

Electrophoresis is the motion of particles relative to a surrounding fluid driven by a uniform electric field. In conventional electrophoresis, the electrophoretic velocity grows linearly with the applied field. Nonlinear effects with a quadratic speed vs field dependence are gaining research interest since an alternating current field could drive them. Here, we report on the giant nonlinearity of electrophoresis in a nematic liquid crystal in which the speed grows with the fourth and sixth powers of the electric field. The mechanism is attributed to the shear thinning of the nematic environment induced by the moving colloid. The observed giant nonlinear effect dramatically enhances the efficiency of electrophoretic transport.

Synergistic Stabilization of Zn Metal Anodes by 3D Carbon Frameworks with Multiple Ion Channels Loaded with Zincophilic BaTiO3 Nanoparticles

Aqueous zinc‐ion batteries (AZIBs) suffer from rampant Zn dendrites growth, corrosion and sluggish transport kinetics, all of which have a serious impact on their performance and practical applications. Therefore, porous carbon nanofibers (BTO@PCNFs) loaded with BaTiO3 nanoparticles (BTO NPs) are constructed as a multifunctional interlayer for stabilizing the Zn anodes. Owing to the synergistic effect of BTO NPs and 3D porous carbon framework, this interlayer can achieve uniform electric field distribution, accelerate Zn2+ migration, and promote ion flux homogenization, thus leading to uniform Zn deposition. Meanwhile, the BTO@PCNFs interlayer demonstrates excellent anti‐corrosion effect, which can effectively prevent the side reactions. Benefiting from the synergistic effect of interlayers, the BTO@PCNFs multifunctional interlayers achieve a comprehensive optimization of the Zn anodes. The BTO@PCNFs‐Zn electrode exhibits lower nucleation overpotential (33.5 mV) at 0.5 mA cm−2. The Zn//Zn symmetrical cell with BTO@PCNFs interlayer exhibits ultra‐low overpotential (14 mV) and ultra‐long cycle life (5250 h at 0.5 mA cm−2). Even at high current density (30 mA cm−2), the BTO@PCNFs‐Zn electrode can be stably cycled for more than 830 h, achieving an ultra‐high cumulative capacity of 12 450 mAh cm−2. The multifunctional interlayers can provide a reference for the design of high‐performance Zn anodes.

A 3D Hierarchical Host with Gradient-Distributed Dielectric Properties toward Dendrite-free Lithium Metal Anode.

The conventional conductive three-dimensional (3D) host fails to effectively stabilize lithium metal anodes (LMAs) due to the internal incongruity arising from nonuniform lithium-ion gradient and uniform electric fields. This results in undesirable Li "top-growth" behavior and dendritic Li growth, significantly impeding the practical application of LMAs. Herein, we construct a 3D hierarchical host with gradient-distributed dielectric properties (GDD-CH) that effectively regulate Li-ion diffusion and deposition behavior. It comprises a 3D carbon fiber host modified by layer-by-layer bottom-up attenuating Sb particles, which could promote Li-ion homogeneously distribution and reduce ion concentration gradient via unique gradient dielectric polarization. Sb transforms into superionic conductive Li3Sb alloy during cycling, facilitating Li-ion dredging and pumps towards the bottom, dominating a bottom-up deposition regime confirmed by COMSOL Multiphysics simulations and physicochemical characterizations. Consequently, a stable cycling performance of symmetrical cells over 2000 h under a high current density of 10 mA cm-2 is achieved. The GDD-CH-based lithium metal battery shows remarkable cycling stability and ultra-high energy density of 378 Wh kg-1 with a low N/P ratio (1.51). This strategy of dielectric gradient design broadens the perspective for regulating the Li deposition mechanism and paves the way for developing high-energy-density lithium metal anodes with long durability.

A 3D Hierarchical Host with Gradient‐Distributed Dielectric Properties toward Dendrite‐free Lithium Metal Anode

AbstractThe conventional conductive three‐dimensional (3D) host fails to effectively stabilize lithium metal anodes (LMAs) due to the internal incongruity arising from nonuniform lithium‐ion gradient and uniform electric fields. This results in undesirable Li “top‐growth” behavior and dendritic Li growth, significantly impeding the practical application of LMAs. Herein, we construct a 3D hierarchical host with gradient‐distributed dielectric properties (GDD‐CH) that effectively regulate Li‐ion diffusion and deposition behavior. It comprises a 3D carbon fiber host modified by layer‐by‐layer bottom‐up attenuating Sb particles, which could promote Li‐ion homogeneously distribution and reduce ion concentration gradient via unique gradient dielectric polarization. Sb transforms into superionic conductive Li3Sb alloy during cycling, facilitating Li‐ion dredging and pumps towards the bottom, dominating a bottom‐up deposition regime confirmed by COMSOL Multiphysics simulations and physicochemical characterizations. Consequently, a stable cycling performance of symmetrical cells over 2000 h under a high current density of 10 mA cm−2 is achieved. The GDD‐CH‐based lithium metal battery shows remarkable cycling stability and ultra‐high energy density of 378 Wh kg−1 with a low N/P ratio (1.51). This strategy of dielectric gradient design broadens the perspective for regulating the Li deposition mechanism and paves the way for developing high‐energy‐density lithium metal anodes with long durability.

Simulation study for anode engineering of AlGaN/GaN double-channel hybrid anode Schottky barrier diode

In this work, a new structure of double-channel hybrid anode Schottky barrier diode with dual anode metal (DCH-DM-HAD) was proposed, and the preliminary investigation of the device's electrical characteristic was conducted by using Silvaco TCAD tools. The double-channel hybrid anode diode (DCH-HAD) and single channel hybrid anode diode (SCH-HAD) were compared and it was found that the Ron at lower forward bias is twice as large as the higher bias, which is attributed to different Von of upper channel and lower channel. It can be avoided by setting different metal structures at anode. Besides, the Von decreases with increasing thickness of the barrier layer, but the reverse leakage current increases fast. Finally, the breakdown voltage of three different structures of hybrid anode diodes were compared, and it is found that replacing nickel with tungsten is harder to form uniform electric field due to difference of workfunction of tungsten and nickel. Nonetheless, these kinds of diodes own excellent electrical characteristics.

Characterizing the Janus colloidal particles in AC electric field and a step towards label-free cargo manipulation

In recent years, researchers have been exploring Janus particles, a unique type of colloidal system, which has gained enormous attention across diverse fields, from soft matter physics to biology. These particles, possessing an asymmetric surface, can be manipulated in the fluid using external energy sources. This versatility makes them suitable for mimicking biological systems and applications like cargo transportation, drug delivery, biosensing, and environmental cleanup. The study focuses on the response of metal-dielectric (Ti-PMMA) Janus spheres in the AC field, created through the Physical Vapor Deposition (PVD) technique. When subjected to a uniform AC electric field, these particles exhibit different dynamic behaviors at various frequency ranges. The particles show diverse responses from induced-charge electrophoresis (ICEP: 500 Hz-80 kHz) to reversed motion (r: ICEP:100 kHz-1 MHz) and linear chain formation (1 MHz). Additionally, they randomly cluster near the lower characteristic frequency (800 Hz) of the ICEP, whereas they exhibit the 3D motion at frequencies (100 Hz) below this lower characteristic value. The mechanisms behind these dynamic phenomena could be explained by considering the concept of electric double layer (EDL), self-dielectrophoresis (sDEP), dipolar interactions, hydrodynamic interactions, and electrothermal effects. These active Janus Colloids are further leveraged to manipulate 1 µm diameter PMMA passive microparticles and E. coli bacteria at 1 kHz, showcasing their potential applications in cargo delivery under various microfluidic research areas. The manipulation of payloads could be explained based on dielectrophoretic trapping due to locally generated field gradients around the surface of the Janus sphere. Therefore, the present work offers an unprecedented opportunity to study such out-of-equilibrium complex active matter systems and create novel functional materials. Moreover, it could also be extended as a fuel-free microrobotics system for various biomedical applications such as sensing and on-demand drug or cargo delivery inside the microfluidics chamber.

Charge Conservation beyond Uniformity: Spatially Inhomogeneous Electromagnetic Response in Periodic Solids

Nonlinear electromagnetic response functions have reemerged as a crucial tool for studying quantum materials, due to recently appreciated connections between optical response functions, quantum geometry, and band topology. Most attention has been paid to responses to spatially uniform electric fields, relevant to low-energy optical experiments in conventional solid state materials. However, magnetic and magnetoelectric phenomena are naturally connected by responses to spatially varying electric fields due to Maxwell’s equations. Furthermore, in the emerging field of moiré materials, characteristic lattice scales are much longer, allowing spatial variation of optical electric fields to potentially have a measurable effect in experiments. In order to address these issues, we develop a formalism for computing linear and nonlinear responses to spatially inhomogeneous electromagnetic fields. Starting with the continuity equation, we derive an expression for the second-quantized current operator that is manifestly conserved and model independent. Crucially, our formalism makes no assumptions on the form of the microscopic Hamiltonian and so is applicable to model Hamiltonians derived from tight-binding or calculations. We then develop a diagrammatic Kubo formalism for computing the wave vector dependence of linear and nonlinear conductivities, using Ward identities to fix the value of the diamagnetic current order by order in the vector potential. We apply our formula to compute the magnitude of the Kerr effect at oblique incidence for a model of a moiré-Chern insulator and demonstrate the experimental relevance of spatially inhomogeneous fields in these systems. We further show how our formalism allows us to compute the (orbital) magnetic multipole moments and magnetic susceptibilities in insulators. Turning to nonlinear response, we use our formalism to compute the second-order transverse response to spatially varying transverse electric fields in our moiré-Chern insulator model, with an eye toward the next generation of experiments in these systems. Published by the American Physical Society 2024

Smart droplet bouncing on dielectric surfaces under uniform electric fields

The electric field is considered an effective stimulus to control droplet bounce or adhesion on demand on solid surfaces, which is important for various applications, including water harvesting and oil/water separation. However, it remains challenging to switch droplet bouncing/adhering on electrode surfaces smartly. Herein, we present a smart control method for droplet bouncing on dielectric surfaces by coupling charge transfer with contact electrification and a uniform electric field. Subject to electric fields, water droplets carrying the like charges in the insulating silicone oil present electric field-direction-dependent impact behaviors, bifurcating into bouncing and adhesion on hydrophobic and hydrophilic surfaces. Furthermore, oppositely charged water droplets with contact electrification led to contrary bouncing behaviors on hydrophobic and hydrophilic surfaces. The transfer charges and electric forces in the experiments are especially quantitively analyzed. By constructing dielectric pairs with hydrophobic and hydrophilic surfaces, reciprocating bouncing or selective adhesion can be modulated via switching electric field directions. This route of separately charging droplets and building electric fields facilitates droplet manipulation techniques and applications.

Diffusivity of individual adsorbed water molecules at an Fe2O3 − Hematite/Water interface under external electric-field conditions

The dynamical properties of physically and chemically adsorbed water molecules at a pristine hematite-(001) surfaces have been studied by non-equilibrium ab-initio molecular dynamics in the constant-volume, constant-temperature ensemble at room temperature, under externally-applied, uniform static electric fields of increasing intensity. Significant alterations in the dipole moment and self-diffusion constant were found vis-à-vis zero-field conditions, as well as shifting of the probability distribution of individual molecular self-diffusivities. For instance, application of static fields was found to increase the self-diffusion of water molecules at the α-hematite Fe2O3 surface, effectively due to some extent of ‘dipole-locking’ in the direction of the applied field.

Ion‐Sieving Effect Enabled by Sulfonation of Cellulose Separator Realizing Dendrite‐Free Zn Deposition

AbstractAqueous zinc‐ion batteries (AZIBs) hold great potential for grid‐scale energy storage systems, owing to their intrinsic safety and low cost. Nevertheless, their industrialization faces challenges of severe Zn dendrites and parasitic reactions. In this study, sulfonated cellulose separator (denoted as CF‐SO3) with low thickness, exceptional mechanical strength, and large ionic conductivity is developed. Benefiting from the electrostatic repulsion between ─SO3− functional groups and SO42− anions and the strongly interaction between ─SO3− and Zn2+ cations, the migration of SO42− anions can be restricted, the 2D diffusion of Zn2+ ions at the surface of Zn electrode can be suppressed, and the desolvation of hydrated Zn2+ ions can be promoted. Concurrently, the homogeneous nanochannels within CF‐SO3 separator can ensure uniform electric field and Zn2+ ion flux. With these benefits, the CF‐SO3 separator enables Zn//Zn cells to run stably for 1200 h at 4 mAh cm−2 by facilitating oriented and dendrite‐free Zn deposition. Under a large depth of discharge of 68.3%, a life span of 400 h can still be achieved. Additionally, the reliability of CF‐SO3 separator is confirmed in Zn//MnO2 and Zn//H11Al2V6O23.2 full batteries with high mass loading conditions. This work provides valuable guidance for the advancement of high‐performance separators of AZIBs.

Exploring non-perturbative corrections in thermodynamics of static dirty black holes

This research delves into an extensive exploration of the thermodynamic characteristics exhibited by a contaminated black hole subject to a uniform electric field, within the theoretical framework of the Einstein-Nonlinear Electrodynamics (ENE)-dilaton theory. The investigation encompasses a thorough analysis of diverse thermodynamic facets, encompassing heat capacity, Helmholtz free energy, and internal energy. Through this comprehensive examination, valuable insights are provided into the distinctive behavior of the black hole when subjected to the influence of the electric field. Moreover, our study embarks on an exploration of the nuanced interplay between quantum effects and the thermodynamic profile, with a particular focus on scrutinizing the quantum-corrected entropy. This approach allows for a deeper understanding of the intricate relationship between quantum mechanics and the thermodynamic attributes exhibited by the system. By doing so, we aim to illuminate the non-perturbative corrections inherent in this intricate system, thereby contributing to a holistic comprehension of the altered thermodynamics characterizing dirty black holes within the confines of the specified theoretical framework. In essence, this research endeavors to uncover the subtleties of the modified thermodynamic landscape governing black holes tainted by external factors, specifically within the context of the ENE-dilaton theory. The outcomes of this study promise to extend our understanding of the intricate interactions within such complex systems, offering valuable insights into the non-perturbative corrections that manifest in their thermodynamic behavior.

Effects of rainbow gravity on an electron confined to a triangular well and a periodic potential

We investigate quantum effects concerning the modification of the background via rainbow gravity on an electron. We employ the nonrelativistic approximation of the Dirac equation to analyze these effects in depth. We initially study the interaction between an electron and a uniform electric field, by exploring confinement of the particle to a triangular potential well. We find systematic alterations in the energy levels reliant on the rainbow parameter ϵ. Additionally, we investigate a particle in a periodic potential resembling a ring. We also find consistent alterations in energy levels due to changes in the background via rainbow functions. As in the previously analyzed scenario, the larger the rainbow parameter, the lower the obtained energy levels. These findings underscore a systematic influence of modified gravity on particle dynamics in quantum scenarios.

Electric field mapping by Pockels effect and I(V) characteristic of CdTe nuclear detectors by different Pt contact deposition

In this work, we present the optimized principal methods of surface cleaning and treatment for CdTe nuclear detectors, namely: powder lapping, polishing and chemical etching mainly by Br- Methanol. We have studied the electric field mapping by Pockels effect technique. We made a comparison between the three main methods of Pt contact deposition: molecular beam epitaxy, cathode sputtering and the electroless (autocatalytic) methods in term of I(V) characteristic and electric field mapping. The two first method show: i) quite high uniform electric field, ii) the characteristic I(V) is non-uniform, iii) the detection suffer from the polarization effect. The I (V) characteristic shows that the contact is not ohmic. It is in the reversible I ∼ Vn with n varying from 0.643 to 1.651. The optimized contact deposit by electroless technique seems to be the more suitable one for detection with 2.10−8 A current at 200 V, a quite high uniform electric field up to 7 kV/cm, an absence of polarization effect and a spectrometric quality of nuclear detection.

Transient electrophoresis of a conducting cylindrical colloidal particle suspended in a Brinkman medium

The time-dependent electrophoresis of an infinitely cylindrical particle in an electrolyte solution, saturated in a charged porous medium after the sudden application of a transverse or tangential step electric field, is investigated semi-theoretically with an arbitrary double-layer thickness in an arbitrary direction relative to the cylinder. The time-dependent modified Brinkman equation with an electric force term, which governs the fluid flow field, is used to model the porous medium and is solved by using the Laplace transform technique. Explicit formulas, for the time-dependent electrophoretic velocity of the cylindrical particle in Laplace’s transform domain, have been derived for both axially and transversely when the uniform electric fields are imposed. They can also be linearly superimposed for an arbitrarily oriented relative to the electric field. Semi-analytical results for the electrophoretic velocities are presented as functions of the dimensionless elapsed time, the ratio of the particle radius to the Debye length, the particle-to-medium density ratio, and the permeability parameter of the porous medium. The results demonstrate, in general, that the growth of the electrophoretic velocities with the time scale are more slower for high permeability, and the effect of the relaxation time for unsteady electrophoresis is found to be negligible, regardless of the thickness of the double layer, the relative mass density or the permeability of the medium. The normalized transient electrophoretic velocities exhibit a consistent upward trend as the ratio of the particle radius to the Debye screening length increases. Conversely, they display a consistent downward trend as the particle-to-fluid density ratio increases, while all other parameters remain constant. The effect of the relaxation time for the transient electrophoresis is much more important for a cylindrical particle than for a spherical particle due to its smaller specific surface area.

Three-dimensional Ordered Macroporous Flexible Electrode Design toward High-Performance Zinc-Ion Batteries.

Flexible zinc-ion batteries (ZIBs) have been considered to have huge potential in portable and wearable electronics due to their high safety, cost efficiency, and considerable energy density. Therein, the design and construction of flexible electrodes significantly determine the performance and lifespan of flexible battery devices. In this work, an ultrathin flexible three-dimensional ordered macroporous (3DOM) Sn@Zn anode (60 μm in thickness) is presented to relieve dendrite growth and expand the lifespan of flexible ZIBs. The 3DOM structure can ensure uniform electric field distribution, guide oriented zinc plating/stripping, and extend the lifespan of anodes. The rich zincophilic Sn sites on the electrode surface significantly facilitate Zn nucleation. Accordingly, a lowered nucleation overpotential of 8.9 mV and an ultralong cycling performance of 2400 h at 0.1 mA cm-2 and 0.1 mAh cm-2 are achieved in symmetric cells, and the 3DOM Sn@Zn anode can also operate in deep cycling for over 200 h at 10 mA cm-2 and 5 mAh cm-2. A flexible 3DOM MnO2/Ni cathode with a high structural stability and a high mass-specific capacity is fabricated to match with the anode to form a flexible ZIB with a total thickness of 200 μm. The flexible device delivers a high volumetric energy density of 11.76 mWh cm-3 at 100 mA gMnO2-1 and a high average open-circuit voltage of 1.5 V and exhibits high-performance power supply under deformation in practical application scenarios. This work may shed some light on the design and fabrication of flexible energy-storage devices.

Capture of CO2 by Melamine Derivatives: A DFT Study Combining the Relative Energy Gradient Method with an Interaction Energy Partitioning Scheme.

A theoretical study of the interaction between melamine and CO2 was carried out using density functional theory (DFT) with the B3LYP-D3(BJ)/aug-cc-pVTZ level of theory. The presence of anions interacting with melamine transforms the weakly bonded tetrel complexes into adducts. Thus, melamine acts as an FLP (frustrated Lewis pair) with acid groups (NHs as hydrogen bond donors) and a base group (N of the triazine ring). The application of the relative energy gradient formalism (REG) along the reaction coordinate has demonstrated that the ability of the melamine-anion systems to capture CO2 is linked to its capacity to polarize the CO2 molecule. These results have been confirmed by placing the melamine:CO2 complex in a uniform electric field with different strengths.

The noncommutative Dirac oscillator with a permanent electric dipole moment in the presence of an electromagnetic field

In this work, we investigate the noncommutative Dirac oscillator (NCDO) with a permanent electric dipole moment (EDM) in the presence of an electromagnetic field. We consider a radial magnetic field generated by anti-Helmholtz coils and the uniform electric field of the Stark effect. Next, we determine the exact solutions of the system, given by the Dirac spinor and by the relativistic energy spectrum. We note that such a spinor is written in terms of the generalized Laguerre polynomials, and such a spectrum is a linear function on the potential energy U and depends on the quantum numbers n and m, spin parameter s, and of four angular frequencies: ω, ω¯ , ω θ , and ω η , where ω is the frequency of the DO, ω¯ is a type of ‘cyclotron frequency’, and ω θ and ω η are the NC frequencies of position and momentum. We graphically analyze the behavior of the spectrum as a function of these frequencies for three different values of n, with and without the influence of U. Besides, as an interesting result, another interpretation can be given for the origin of the nonminimal coupling of the DO, which would be through a neutral fermion with EDM in a radial magnetic field. Finally, we also analyze the nonrelativistic limit of our results, and comparing our problem with other works, we verified that our results generalize some particular cases in the literature.

Self-powered powerline monitor with strong anti-interference based on Maxwell’s displacement current-driven LED

A smart grid is a new generation power system, which realizes the interconnection of information in intelligent, efficient, and stable operation modes. Thus, high-voltage monitoring is an important part of ensuring efficient power transmission in a smart grid. However, traditional voltage monitors that rely on wired connections have limitations in meeting the adaptability requirement for smart grids. In this work, inspired by the double-TENG structure, we propose a self-powered high-voltage monitoring device with strong anti-interference, namely, the Maxwell’s displacement current-driven lighting emitting diode (MDC-LED), and proved that the MDC-LED with four electrodes can reorganize the electric field near the powerline, leading to an approximately uniform electric field. Therefore, the light output from the MDC-LED is highly sensitive to the electrical signal of the powerline and has a strong anti-device vibration. Because of the MDC-LED’s high sensitivity to alternating electric fields, it can detect the electric pollution in the powerline, as well as the powerline’s vibration frequency and amplitude. We believe the MDC-LED can provide a novel technical approach for the development of detection systems for use in smart grids.

Blocking the Dendrite‐Growth of Zn Anode by Constructing Ti4O7 Interfacial Layer in Aqueous Zinc‐Ion Batteries

AbstractZinc metal is a promising choice as a high‐capacity and cost‐effective anode for aqueous zinc‐based batteries. However, it faces challenges related to low cycling stability and poor reversibility due to parasitic reactions and the growth of zinc dendrites. In this study, a solution is proposed by introducing a conductive Ti4O7 layer on the zinc anode to enhance electrode stability. The Ti4O7 layer serves a dual purpose, effectively preventing spontaneous corrosion of the zinc anode in the electrolyte, thereby inhibiting the hydrogen evolution reaction and the generation of byproducts. Simultaneously, it promotes Zn nucleation and ensures a uniform electric field distribution, resulting in homogeneous Zn plating and stripping compared to using a bare zinc anode. Consequently, the Ti4O7‐coated Zn anode experiences a significant reduction in over‐potential, demonstrating long‐term stability and dendrite‐free behavior. This outcome ensures low polarization potential and high cycling stability in zinc‐ion batteries. The work underscores the potential of conductive oxides in the development of stable metal electrodes.