Charge injection at copper/polyethylene (Cu/PE) contacts is closely associated with charge accumulation in high-voltage (HV) cable accessories and other polymer-insulated electrical systems. In this work, electric double layers (EDLs) at Cu/PE interfaces were examined by first-principles calculations, with emphasis on how interfacial polarity alters the local electrostatic potential and the potential barrier between Cu and PE. The results indicate that an EDL with negative charge on the Cu side and positive charge on the PE side decreases the barrier, making charge injection across the interface more favorable. When the polarity is reversed, with positive charge on the Cu side and negative charge on the PE side, the PE-side potential rises, the interfacial barrier increases, and charge injections are consequently restrained.

The oxygen evolution reaction (OER) constitutes a critical bottleneck in water electrolysis for hydrogen production owing to its sluggish four-electron transfer kinetics. Double perovskite oxides (A2BB'O6) have emerged as exceptional OER catalysts distinguished by their stable crystal frameworks and flexible active-site tunability. Crucially, the alternating ordering of B and B' cations at octahedral positions creates a unique lattice enriched with oxygen vacancies. Leveraging these intrinsic structural advantages, we synthesized a porous Ru-doped double perovskite oxide Sr2Fe1.9Ru0.1O6-delta (SFRO-850) featuring increased oxygen vacancies via a sol-gel route. Electrochemical measurement shows that SFRO-850 exhibits outstanding OER activity with a low overpotential of 326 mV at a current density of 10 mA cm-2 and a Tafel slope of 67.48 mV dec-1, superior to the undoped material and its counterparts. The results validate the efficacy of the double perovskite framework as a superior platform for hosting catalytically active sites, offering a viable pathway toward high-performance, low-noble-metal-content OER catalysts.

The active site of MoS2, predominantly located at the crystalline edge, limits selectivity for the CO2 reduction reaction (CO2RR). Single-Atom Catalysts (SACs), have emerged as a promising avenue to enhance the catalytic performance of MoS2, owing to their high catalytic selectivity on the basal plane and tunable activity in various chemical reactions. In this regard, transition metals from the 8B and 1B groups (Cr, Cu, Sc, Ti, V, and Ni) were investigated as dopants on the basal plane for the first time, employing first-principles calculations based on a 4 × 4 × 1 supercell of the MoS2 monolayer. The Ti/MoS2 catalyst was identified as the most stable among the SACs, attributed to its optimal formation energy. Various Ti-doped models were analyzed, encompassing energy band structure, density of states, charge differential density, Bader charge, and Gibbs free energy. Our findings indicate that Ti induces diminished electron binding, thereby weakening C[double bond, length as m-dash]O with lower energy, consequently enhancing the availability of surface sites and facilitating catalytic reactions. In our investigation of possible reaction pathways, the preferred CO2RR pathway was identified as the reverse water gas conversion (RWGS), with the rate-limiting step being CO2 hydrogenation into carboxyl (*COOH). The Ti modification model on the MoS2 basal surface demonstrated exceptional catalytic performance, reducing the rate-limiting step to 0.177 eV, which is 17 times lower than that of pure MoS2. These calculational results provide valuable theoretical insights for designing highly efficient SACs on MoS2-based functional materials.

The stochastic and intermittent characteristics of renewable energy pose significant challenges to energy utilization and power system stability. The reversible solid oxide cell (RSOC), as an emerging multi-energy conversion technology, exhibits high efficiency in both electrolysis and power generation modes, offering a promising solution to renewable energy integration and energy supply issues. However, RSOC performance degrades over time, and its average efficiency decay rate directly influences capacity investment decisions and day-ahead scheduling strategies. To address this, a comprehensive energy system model considering RSOC capacity is developed, with a detailed representation of each subsystem. A bi-level optimization framework is then proposed, where the upper level minimizes system investment and operation costs, and the lower level optimizes day-ahead scheduling costs. The model explicitly accounts for RSOC efficiency degradation and lifetime attenuation. Particle swarm optimization is applied to determine the optimal capacity configuration. Case studies demonstrate that the proposed model enhances system economics, promotes multi-energy complementarity, and prolongs RSOC lifetime, providing theoretical and technical support for the planning and operation of integrated energy systems with RSOC.

Achieving selective CO2 methanation under photothermal conditions requires catalysts capable of maintaining non-equilibrium interfacial states that balance reduction and oxidation processes-an ability rarely attainable through conventional thermal synthesis. Here, we propose a rapid Joule-heating strategy that injects energy in a kinetically non-equilibrium, current-induced manner, triggering rapid exsolution of nanoparticles and electronic reconstruction within seconds. This approach creates LaNiO3-La2NiO4 heterostructures embedded with socketed alloying Ni-Fe nanoparticles, where the coupled oxygen migration and charge redistribution give rise to electronically modulated metal/oxide interfaces. The kinetically confined process produces finely dispersed, electronically asymmetric active sites while avoiding the structural degradation typical of slow thermal treatments. The optimized catalyst (LNF-JH1100) achieves a CH4 production rate of 166.5 mmol g(-1) h(-1) with >97% selectivity at 350 degrees C, showing a remarkable activity, selectivity, and stability. Combined spectroscopic and theoretical analyses reveal that this non-equilibrium interface modulates the local electron density and intermediate binding sequence, and is associated with a shift in the dominant reaction pathway from a single HCOOH-mediated surface hydrogenation pathway prone to CO release to a cooperative HCOO/HCOOH cycle that promotes direct CH4 formation. This work demonstrates the potential of rapid Joule heating as an effective route to couple structural exsolution with electronic reconfiguration, offering new opportunities for the rational design of adaptive, high-performance photothermal catalysts.

The electrochemical co-conversion of CO2 and H2O into valuable products is a promising approach toward carbon-neutral energy systems. Alloy exsolution from perovskite lattices has emerged as an effective strategy to engineer catalytic interfaces, yet the mechanistic influence of exsolved bimetallic species on CO2/H2O co-electrolysis remains insufficiently clarified. To address this gap, density functional theory (DFT) calculations were performed in this study to systematically examine how NiFe alloy clusters exsolved from the LSFNO (La0.7Sr0.3Fe0.9Ni0.1O3-delta) (111) surface modify the electronic structure of the interfacial region and promote the RWGS reaction in CO2/H2O co-electrolysis. Our work highlights bimetallic alloy exsolution as a powerful strategy for improving co-electrolysis catalysts and offers valuable guidance for the rational design of next-generation high-entropy oxide systems.

Enhancing the wear resistance and anti-icing performance of steel-reinforced aluminum conductors (ACSR) in transmission lines has become an active area of research. Multifunctional composite coatings were fabricated on aluminum conductor steel-reinforced (ACSR) wires by generating a porous layer through micro-arc oxidation (MAO) and subsequently sealing it with polytetrafluoroethylene (PTFE) particles via electrophoretic deposition (EPD). The influence of EPD voltage on the hydrophobicity and ice hanging rates of MAO/PTFE-coated Al wires was investigated. Comprehensive microstructural and compositional analyses were conducted using SEM, XPS, XRD, and EDS. Tribological properties (friction/wear) and corrosion resistance in a salt-spray atmosphere were also systematically evaluated. Results demonstrate that PTFE incorporation markedly improves the tribological and anticorrosion performance of MAO coatings, attributed to effective sealing of the porous structure. The superhydrophobic PTFE layer also suppresses ice and water accumulation on conductor surfaces. The underlying mechanisms governing these enhancements are elucidated. Life cycle cost analysis further confirms the economic advantages of this approach. This MAO composite coating technology presents a promising solution for extending the service life and minimizing maintenance of aluminum conductors operating in aggressive environments.

The development of high-power electronics demands polymer dielectrics with high thermal stability and dielectric performance. However, most materials suffer performance degradation in harsh environments due to increased electrical conductivity. Herein, a physics-informed data-driven topology-supported precursor screening strategy was proposed to design quasi-branched polyimides (QbPIs) with enhanced energy density (Ue) and charge-discharge efficiency (η) at elevated temperatures. By constructing automated screening workflow, key descriptors involving HOMO-LUMO gap (Gap) and dielectric constant (εr) were sufficiently evaluated to form multi-parameter ranking framework, in which melamine was identified as the optimal topological center for constructing QbPIs with tunable topological ratios (0–2.5%). Notably, the resulting star-shaped topological structure effectively regulates charge transport and dielectric behavior through a cooperative mechanism. It increases the Gap, introduces deep-level traps, and stabilizes the Ag/dielectric interface, which together suppress conduction loss and charge injection, effectively disrupting long-range charge-transport pathways. The optimized QbPI-1.75 exhibited outstanding capacitive performance, delivering 5.39 J cm−3 (Ue) with 94% (η) at 25 °C, and retaining 3.29 J cm−3 with 78.41% at 200 °C, far exceeding that of pure PI (1.35 J cm−3, 87.6% η at 25 °C). This work establishes a fundamental structure-property relationship for topological PIs and provides a facile design strategy applicable to other high-temperature polymer dielectrics.

The electric double layer (EDL) at the copper/polyethylene (Cu/PE) interface critically affects space charge injection and insulation performance of high-voltage cables and their accessories, yet its molecular-level regulation remains unclear. This study systematically investigates the effects of different EDL structures on the potential distribution and interfacial barrier at the Cu/PE interface using first-principles calculations. The results show that the EDL-induced built-in electric field significantly modulates the potential of the PE layer, while the Cu layer remains largely unaffected. When the Cu side is positively charged and PE negatively charged, the EDL increases the interfacial barrier, suppressing charge injection and restricting PE molecular diffusion. Conversely, an EDL with negatively charged Cu and positively charged PE lowers the barrier, promotes charge injection, and enhances the diffusion of PE molecules. Notably, Na-induced EDL enhances PE diffusivity, whereas F-induced EDL restricts molecular motion. This work elucidates the regulatory mechanisms of EDL on both electronic and kinetic properties at the Cu/PE interface, providing a theoretical foundation for improving high-voltage cable insulation.

Protonic ceramic fuel cells (PCFCs) are one of the most promising energy conversion technologies because of the high efficiency and environmental friendliness. However, the lower operating temperature causes sluggish reaction kinetics and degradation, especially for the cathode side. In this work, Ruddlesden-Popper (R-P) perovskite Sr3Fe2O7-s is optimized by doping Pr at A-site, leading to an enhancement of electrical conductivity and polarization resistance. Higher oxygen vacancy concentration and larger active area facilitate the ion conduction and oxygen reduction reaction, increasing the electrochemical performance by 14%. These results demonstrate the potential of Sr3-xPrxFe2O7-s as active cathode for PCFCs.

Solid Oxide Electrolysis Cell (SOEC) technology, recognized for its high energy conversion efficiency, offers a promising pathway for converting CO2 electrochemically into valuable chemicals, thereby contributing to carbon neutrality goals. However, the widespread adoption of SOEC is hindered by the limited catalytic performance of conventional fuel electrodes based on Ni-YSZ. To address this challenge, this work develops the novel fuel electrodes composed of layered perovskite oxides, (La4Sr4)0.9Ti7.2 & times;0.4Cu0.4O26 (LSTXCu, where X = Ni, Co, Fe), decorated with exsolved Cu-X alloy nanoparticles via a Cu-induced process at low temperature. The in-situ formed X-Cu alloy nanoparticles, creating heterogeneous interfaces with the perovskite substrate, significantly enhance the electrocatalytic activity towards the CO2 reduction reaction (CO2RR). Electrochemical analysis exhibits that the full cells with the LSTXCu-r fuel electrode exhibited outstanding CO2 electrolysis performance, delivering maximum current densities of 1.98 A cm-2 at 2.0 V and 850 degrees C in pure CO2 atmosphere. The values represent a substantial performance improvement of 152.3 %, compared to cells using LSTX-r electrodes with sole exsolved X metal nanoparticles.

Charge and water accumulation in oil/paper insulation systems are widely recognized as critical factors affecting their electrical and insulating properties. However, the molecular-level mechanisms underlying these phenomena remain poorly understood. In this study, we employ ab initio molecular dynamics simulations to investigate the effects of excess electrons and water molecules on charge trapping and structural degradation in mineral oil (MO), vegetable oil (VO), and insulating paper. Our results demonstrate that excess electrons enhance the trap depth in oil/paper insulation due to self-trapping behavior. The presence of water molecules further increases the trap depth, with the most pronounced effect observed in VO, which can be attributed to chemical reactions between water clusters and ester groups. Additionally, electron accumulation promotes the formation of water ion clusters during these reactions, a process that appears to play a pivotal role in the degradation of oil/paper insulation. These findings provide critical insights into how excess electrons and water molecules influence charge trapping and material degradation, offering valuable guidance for enhancing the insulating performance of oil/paper materials in power transformers.

Co-electrolysis of CO2 and H2O offers a promising route for efficient and controllable syngas production from greenhouse gases and water. However, the atomic-scale reaction mechanism remains elusive, especially on complex oxide surfaces. In this study, we employ density functional theory (DFT) to investigate the adsorption and activation of CO2 and H2O on the FeMoO-terminated (001) surface of Sr2Fe1.5Mo0.5O6 (SFM), a double perovskite of growing interest for solid oxide electrolysis. Our results show that CO2 strongly interacts with surface lattice oxygen, adopting a bent configuration with substantial charge transfer. In contrast, H2O binds more weakly at Mo sites through predominantly electrostatic interactions. Co-adsorption analyses reveal a bidirectional interplay: pre-adsorbed H2O enhances CO2 binding by altering its adsorption geometry, whereas pre-adsorbed CO2 weakens H2O adsorption due to competitive site occupation. This balance suggests that moderate co-adsorption may facilitate proton–electron coupling, while excessive coverage of either species suppresses activation of the other. Bader charge analysis, charge density differences, and projected density of states highlight the key role of Fe/Mo–O hybridized states near the Fermi level in mediating surface reactivity. These results, obtained for a perfect defect-free surface, provide a theoretical benchmark for disentangling intrinsic molecule–surface and molecule–molecule interactions, and offer guidance for designing high-performance perovskite electrocatalysts for CO2 + H2O co-electrolysis.

As one of the weakest points in high-voltage direct current cables and accessories, the accumulation of space charges at the crosslinked polyethylene (XLPE)/ethylene propylene diene monomer (EPDM) interface coated with silicone oil is crucial to insulating properties. The physical mechanisms underlying this charge accumulation and dissipation phenomenon remain unclear, particularly at the molecular level. Thus, the interfacial space charge accumulation and dissipation behavior at EPDM/XLPE, EPDM/non-polar dimethyl silicone oil (PDMS)/XLPE, and EPDM/polar fluorinated silicone oil (PMTFS)/XLPE interfaces was measured using pulsed electroacoustic (PEA) method, and molecular simulation techniques were employed to calculate the electronic properties across those interfaces. It was found that the transformation law of the interfacial charge polarity does not completely align with the Maxwell-Wagner (MW) model, which is related to the contact type of the interface (with or without silicone oil and the type of silicone oil) and the voltage polarity. The presence of a high interfacial potential barrier is an important factor behind the fact that the transformation law of the interfacial charge polarity does not align with the MW model. The high hole potential barrier (greater than 1 eV) of EPDM/XLPE and EPDM/PMTFS is the reason why the interfacial charges of EPDM/XLPE and EPDM/PMTFS/XLPE remain always positive as the applied negative voltage and temperature increases. Due to the low potential barrier of the EPDM/PDMS/XLPE interface, the polarity of the interfacial charge is always consistent with the polarity of the voltage applied to the medium with a greater conductivity. At 40 degrees C and 60 degrees C, EPDM/XLPE and EPDM/PMTFS/XLPE positive interface charge accumulation is significantly reduced compared to that observed at room temperature under a negative voltage, which is attributed to the enhanced charge injection and migration of XLPE with rising temperature. This study provides theoretical insights for finding an effective coating material to reduce charge accumulation at the cable accessory interface.

This research employed molecular dynamics simulations to explore the distribution of sodium dodecyl sulfate (SDS) at the n-hexane/water interface. Once the SDS concentration surpasses the critical micelle concentration(cmc), a large portion of SDS migrates to the n-hexane/water interface, establishing a thin layer where sulfonic acid groups are oriented towards the water phase and carbon-hydrogen chains are directed towards n-hexane, a small amount of SDS forms spherical micelle with sulfonic acid groups facing the water phase, while carbon-hydrogen chains aggregate in the interior of these spherical structures. The sulfonic acid group of SDS forms multiple h-bonds with water, shows strong interaction energy; while the carbon hydrogen chain itself has only weak van der Waals interactions with surrounding molecules. The thickness of SDS- layer at the n-hexane/water interface is about 2.06 nm, with a maximum number density of about 0.25 per nm3, and average area occupied by a single SDSis about 0.21 nm2. According to radial distribution function (RDF) result, due to the attractive effect of positive and negative charges, the first coordination layer of Na+ ions and oxygen atoms on sulfonic acid groups is about 0.21 nm. This study investigated the distribution of SDS at n-hexane/water interface, vividly demonstrating the mechanism by which SDS reduces the interfacial tension between oil and water, and providing guidance for oilfield development.

As a key insulating material in power equipment, epoxy resins (EP) are often limited in practical applications due to space charge accumulation and mechanical degradation. This study systematically investigates the effects of SiO2 nanoparticle doping on the electrical and mechanical properties of SiO2/EP composites through molecular dynamics simulations and first-principles calculations. The results demonstrate that SiO2 doping enhances the mechanical properties of EP, with notable improvements in Young’s modulus, bulk modulus, and shear modulus, while maintaining excellent thermal stability across different temperatures. Further investigations reveal that SiO2 doping effectively modulates the interfacial charge behavior between EP and metals (Cu/Fe) by introducing shallow defect states and reconstructing interfacial dipoles. Density of states analysis indicates the formation of localized defect states at the interface in doped systems, which dominate the defect-assisted hopping mechanism for charge transport and suppress space charge accumulation. Potential distribution calculations show that doping reduces the average potential of EP (1 eV for Cu layer and 1.09 eV for Fe layer) while simultaneously influencing the potential distribution near the polymer–metal interface, thereby optimizing the interfacial charge injection barrier. Specifically, the hole barrier at the maximum valence band (VBM) after doping significantly increased, rising from the initial values of 0.448 eV (Cu interface) and 0.349 eV (Fe interface) to 104.02% and 209.46%, respectively. These findings provide a theoretical foundation for designing high-performance epoxy-based composites with both enhanced mechanical properties and controllable interfacial charge behavior.

Charge injection is an important factor for the stable operation of power equipment and power system. Our experimental measurements reveal a charge injection barrier of ∼1.2 eV at the Al/Polyethylene (PE) interface. However, previous simulation studies, which accounted for physical and chemical defects, reported charge injection barriers ranging from 2.5 to 5 eV and deviate from our experimental findings. In this paper, we employ first-principles calculation to determine the charge injection barrier at the Al/PE interface, in which the effects of chemical impurities, physical defects, and the morphological complexity of PE including amorphous regions, crystalline regions, and the amorphous/crystalline edge have been systematically investigated. The calculated results demonstrate that specific physical or chemical defects introduce only a single energy trap state, whereas the amorphous/crystalline edge induces multiple energy states. In the amorphous/crystalline edge model, the bandgap is reduced to 7.3 eV and multiple trap states are densely distributed at the amorphous/crystalline edge, which avoids the possibility of highly localized and sparsely distributed trap levels in the space. Consequently, charge injection is likely facilitated through a multi-step-hopping mechanism via these energy trap states at the amorphous/crystalline edge. In this condition, the calculated charge injection barriers of electrons and holes are reduced to 1.56 and 1.33 eV, which is closer to our experimental result of ∼1.2 eV. As the amorphous/crystalline edge widely exists in PE, defects at the amorphous/crystalline edge probably determine the charge injection at the electrode/polymer interface, rather than the specific physical or chemical defects.

In this work, n-hexane, cyclohexane and 2-methylpentane were selected to represent linear-alkane, cycloalkane and branched-alkane, respectively. Based on the dynamic light method (DLS), the viscosity, interfacial tension and diffusion coefficient of n-hexane/CO 2 , cyclohexane/CO2 2 and 2-methylpentane/CO2 2 systems under saturation condition were measured in order to explore the change trend of thermophysical properties of the systems with the same carbon atom number but different molecular structures. The experiments were conducted at the temperatures of 303, 343 and 383 K and at pressures up to 5.64 MPa. The expanded uncertainties(k k = 2)of dynamic viscosity, interfacial tension and diffusion coefficient were 3 %, 3 % and 4.4 % respectively. The experimental results show that n-hexane and 2-methylpentane with similar molecular structure have more similar value of the properties. The effects of different alkane structures on system viscosity, interfacial tension, and diffusion coefficient were explained at the molecular level through radial distribution function, interface thickness, and CO2 2 coordination number. At 303.15 K and 4 MPa, the peak radial distribution function of CO2/ 2 / cyclohexane is 1.845, which is greater than that of CO2/n-hexane 2 /n-hexane and CO2/2-methylpentane 2 /2-methylpentane molecules. It has been proven that the arrangement of CO2/cyclohexane 2 /cyclohexane is more orderly, resulting in higher viscosity and lower diffusion coefficient of the system. The interface thickness of CO2/cyclohexane 2 /cyclohexane is 6.13 nm, which is smaller than CO2/n-hexane 2 / n-hexane (7.53 nm) and CO2/2-methylpentane 2 /2-methylpentane (6.3 nm). The smaller the interface thickness, the more compact the structure, the stronger the intermolecular forces, and the greater the interfacial tension. At 303.15 K and 2 MPa, the number of CO2 2 coordination sites within 1 nm around liquid phase alkanes is 3.96, which is smaller than 4.78 for cyclohexane and 6.62 for 2-methylpentane. Prove that the coordination number is directly proportional to the diffusion coefficient and inversely proportional to viscosity and interfacial tension.

Despite the fact that doping nanoparticles into insulating transformer oil has proven to be an effective method of enhancing its dielectric and electrical properties, it remains unclear how different types and surface conditions of nanoparticles may affect their dielectric and electrical properties. Therefore, the effect of doping various types of BN nanoparticles (nanosphere, nanotube, and nanosheet) in insulating mineral oil (MO) on the diffusion properties of water molecules and electrical properties across the BN/MO interface was investigated using molecular dynamics (MD) and Density Functional Theory (DFT) simulations. Our results show that different surface morphology and grafted functional groups in different types of BN nanoparticles have a significant impact both on the water diffusion behavior and the interfacial potential barrier across the interface between BN and MO. In the MO system directly doped by BN nanospheres, water diffusion behavior is not significantly restricted. However, grafting -NH2 polar groups onto the BN nanoparticle surface may significantly limit the diffusion behavior of water due to the strong attraction between the -NH2 polar groups and water molecules; the most significant effect is with nanospheres, followed by nanotubes and nanosheets. In terms of electrical properties across the interface between BN and MO, the h-BN surface (derived from BN nanosheets and nanotubes) acts as a trap for electrons in MO (−0.59 eV), while the c-BN surface (derived from BN nanospheres) acts as a potential barrier for electrons in MO (1.45 eV), and it is noteworthy that the presence of water molecules near the interface between BN and MO has little impact on the potential barriers. Advancing a fundamental understanding of the electrical and water diffusion properties of MO in correlation with the surface morphology of different types of nanoparticles is key to improving the insulation properties of oil-impregnated power transformers.