Search Results (1,551)

Mass-based circularity indicators, such as ISO 59020:2024, quantify material recovery as a share of total throughput but do not account for chemical composition or functional performance, as a consequence of their sector-agnostic design. In copper metallurgical systems, trace tramp elements (e.g., As, Sb, Bi, Fe, Sn, Ni) present in WEEE-derived scrap, anode slimes, and refinery residues can significantly reduce electrical conductivity. Even at nominal purities of ≥99.7 wt.% Cu, conductivity may drop to 85.0–88.0% IACS, as illustrated by selected reported cases—a level of functional degradation that remains undetected by mass-based accounting. Analysis of Grade A cathode standards (EN 1978:2022, LME Cu-CATH-1, ASTM B115-10:2021) shows that impurity limits as low as 2 ppm (Bi) constrain the achievable share of secondary feed in closed-loop recycling. For a specific flash-smelting–refinery configuration, modeling indicates that secondary feed shares above approximately 30% may lead to impurity accumulation beyond the stated specification constraints unless low-impurity primary copper is introduced. This study introduces the Quality-Adjusted Circularity Indicator (QACI), a conceptual, specification-constrained indicator framework that applies a dilution factor f_dil derived from a binary blending mass balance to adjust ISO 59020:2024 inflow-based circularity indicators using a feed-composition blending constraint anchored to Grade A specification limits. The QACI functions as a feed-composition screening indicator operating at the anode blending stage and does not represent a correction of the full electrorefining system. Parametric scenario analysis across six stylized impurity configurations shows that, at identical mass-based circularity (C_mass = 25%), the QACI ranges from 7.1% to 25.0%. This corresponds to a 1.3- to 3.5-fold difference between the mass-based and quality-adjusted indicator values under the stated feed-composition assumptions, illustrating the potential overestimation introduced when feed-quality constraints are not considered. This ratio quantifies the divergence between two indicator values under stylized conditions and should not be interpreted as a directly measured fold-difference in actual loop-closure performance. Positioned within the ISO 59020:2024 Annex C complementary method space, the QACI is positioned as a first-order screening approach of existing circularity metrics that may inform future research discussion of quality-differentiated approaches in EU secondary metals policy. Full article

The performance and durability of lithium metal solid-state batteries are governed by the dynamic evolution of the lithium/solid-electrolyte (Li/SSE) interface, where electrochemical reactions, mass transport, and mechanical constraints are intrinsically coupled. This review presents an integrated electro-chemo-mechanical framework that links interfacial stripping dynamics to distinct degradation regimes controlled by current density, stack pressure, and thermal activation. We show that stable cycling emerges only within a narrow flux-balance window in which lithium creep and vacancy diffusion compensate stripping-induced volume loss without triggering electrolyte fracture or filament penetration. By synthesizing recent experimental, modeling, and materials engineering advances, the review maps the transitions between void-dominated instability, pressure-assisted stabilization, and stress-limited failure. Particular emphasis is placed on adaptive pressure strategies, compliant interlayer design, and microstructural interface engineering as pathways to expand the operational stability window. The analysis highlights that interfacial stability is not solely a materials property but a systems-level outcome arising from coupled electro-mechanical boundary conditions and temperature-dependent transport processes. This perspective provides design principles for developing next-generation solid-state batteries capable of stable high-rate cycling and long-term reliability. Full article

Glyphosate, the most extensively used herbicide worldwide, is frequently detected in aquatic environments due to its high solubility, persistence, and intensive agricultural application. Its occurrence, together with that of its principal metabolite aminomethylphosphonic acid (AMPA), raises substantial environmental and public health concerns. Conventional water treatment technologies generally exhibit limited efficiency in achieving complete removal and mineralization of this compound. In recent years, advanced electrochemical oxidation processes, and particularly anodic oxidation, have emerged as promising alternatives owing to their ability to generate highly reactive hydroxyl radicals in situ. This review provides the first contaminant-specific and mechanistic assessment dedicated exclusively to the anodic electro-oxidation of glyphosate. In contrast to previous reviews offering broad surveys of electrode materials or generalized evaluations of glyphosate treatment technologies, this work synthesizes all mechanistic, kinetic, and material-dependent insights reported between 2016 and 2025. A comparative analysis of major anode families (including boron-doped diamond (BDD), ${\mathrm{P}\mathrm{b}\mathrm{O}}_2$, mixed-metal oxides, and Magnéli-phase Ti₄O₇) is presented, highlighting glyphosate-specific degradation pathways, intermediate formation, and the operational parameters controlling mineralization efficiency and energy demand. By establishing a structured framework that links electrode properties, radical-generation mechanisms, and pollutant-specific degradation chemistry, this review addresses a critical gap in the literature and provides a scientific basis for designing next-generation electrochemical processes for the efficient and sustainable removal of glyphosate and related organophosphorus contaminants. Full article

The development of efficient catalysts for the glycerol oxidation reaction (GOR) is crucial for advancing direct glycerol fuel cells. This study provides mechanistic insights into the glycerol electro-oxidation reaction (GOR) on Co@Pt/C, Ni@Pt/C, and Sn@Pt/C catalysts using in situ FTIR spectroscopy. While the structural and electrochemical properties of these materials have been previously reported, their reaction pathways and product selectivity under alkaline conditions remain unclear. Electrochemical performance was evaluated through cyclic voltammetry (CV) and chronoamperometry (1.0 M KOH + 1.0 M glycerol), revealing that the bimetallic catalysts exhibited superior catalytic activity compared to Pt/C. Co@Pt/C demonstrated the highest performance, with a 7.5-fold increase in current density relative to Pt/C, followed by Sn@Pt/C (3.4-fold) and Ni@Pt/C (2.8-fold). In situ FTIR analysis identified key oxidation products, including C3, C2, and C1 species, with evidence of both partial and complete oxidation. These findings demonstrate that the core metal plays a key role in governing reaction pathways and C–C bond cleavage, providing important insights for the rational design of anode materials in direct glycerol fuel cells. Full article

This paper presents the design, structural optimization, and two-dimensional (2D) technology computer-aided design (TCAD) simulation of a gallium nitride (GaN) vertical Merged P-i-N/Schottky (MPS) diode incorporating a multi-drift-layer doping profile, composite SiO₂/Si₃N₄ passivation, and field-plate (FP) termination. The proposed device is constructed on an n⁺-GaN substrate with a three-sub-layer n-type drift region and a p-GaN/p⁺-GaN anode region. Systematic TCAD simulations are performed to investigate the dependences of key performance metrics—including knee voltage (V_knee), specific on-resistance (R_on), breakdown voltage (BV), reverse leakage current (J_leak), and Baliga’s figure of merit (BFOM)—on the Schottky metal work function, multi-drift-layer doping concentration, drift-layer thickness, Schottky-to-PN contact length ratio (γ_w), operating temperature, and reverse recovery switching transients. Results demonstrate that the MPS architecture effectively decouples forward conduction loss from reverse blocking capability, overcoming the conventional R_on–BV trade-off. The optimal doping profile (n_mm = 2 × 10¹⁵, n_m = 2 × 10¹⁵, n = 1 × 10¹⁶ cm⁻³) achieves a BFOM of ~31.97 GW·cm⁻² with BV ≈ 5.98 kV and R_on ≈ 1.12 mΩ·cm². Joint doping–thickness optimization further identifies a graded doping profile (n_mm = 2 × 10¹⁵, n_m = 5 × 10¹⁵, n = 1 × 10¹⁶ cm⁻³) combined with layer thicknesses (T_nmm, T_nm, T_n) = (4.49, 5, 20) μm as the overall optimum, achieving BFOM = 55.36 GW·cm⁻² (BV = 6.61 kV, R_on = 0.79 mΩ·cm²)—a +73% improvement, governed by the punch-through/field-stop design principle. The optimal contact ratio of γ_w = 1.33 yields a BFOM of 38.71 GW·cm⁻². Temperature analysis confirms a positive BV temperature coefficient due to drift-region-limited avalanche breakdown, and the BFOM improves monotonically from 33.31 to 37.82 GW·cm⁻² between 200 K and 450 K. Mixed-mode switching simulations show that increasing γ_w substantially reduces reverse recovery charge (Q_rr), demonstrating the strong potential of the proposed MPS diode for high-voltage, high-frequency, and high-temperature power electronic applications. Full article

Inorganic mercury ions (Hg²⁺) are highly toxic, posing a threat to aquatic ecosystems and human health. In this study, iron phthalocyanine (FePc) was anchored onto the surface of MXene via a self-assembly strategy to construct an FePc/MXene-x (F/M-x) heterostructure. Characterization by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption (BET) confirmed that the high specific surface area and good conductivity of MXene effectively inhibited FePc aggregation and increased the exposure of active sites. The F/M-x composite was then modified onto a glassy carbon electrode (GCE) to fabricate an electrochemical sensor, and the detection performance for Hg²⁺ was evaluated using square-wave anodic stripping voltammetry (SWASV). Under optimized conditions (pH = 5.0, accumulation at −1.2 V for 180 s), the F/M-100/GCE exhibited a linear range of 0.1–1.0 μM, a sensitivity of 19.02 μA/μM, and a detection limit of 5.9 nM. The sensor showed good anti-interference ability against coexisting metal ions such as Cd²⁺, Cu²⁺, and Pb²⁺, with a batch-to-batch RSD of 2.03% and a long-term stability RSD of 2.49%. Spike recovery experiments in real water samples (lake water and groundwater) verified the accuracy of the method. This study provides a new electrochemical platform for the rapid detection of trace Hg²⁺ in water environments. Full article

Hydrogen peroxide fuel cells have emerged as a promising class of electrochemical energy conversion device owing to the dual redox character of H₂O₂, its liquid-phase storage, and its ability to operate in air-free environments. In this work, a dual-compartment direct H₂O₂ fuel cell using a Prussian Blue cathode and a tantalum anode, separated by a Nafion 115 proton exchange membrane, was systematically characterized and optimized with respect to electrolyte pH and ionic composition. The influence of pH on OCV was investigated independently in each compartment across the range of pH 2 to 12. In the tantalum compartment, OCV increased non-linearly with pH from 573 mV to 808 mV, driven by the enhanced electrochemical reactivity of the system under alkaline conditions. In the Prussian Blue compartment, OCV decreased from 676 mV to 199 mV with increasing pH, reflecting the instability of the material in alkaline conditions. The effect of the electrolyte ionic composition on average current density was subsequently investigated by varying the concentrations of NaCl and Dy(NO₃)₃. Increasing NaCl from 0 to 2.5 M produced an increase in current density from 0.414 mA/cm² to 0.973 mA/cm², consistent with ohmic resistance reduction through improved ionic conductivity. The addition of Dy(NO₃)₃ produced a positive response with an optimal concentration of $0.05$ M, at which current density reached 1.08 mA/cm², before declining sharply. Under the fully optimized conditions, pH 12 in the tantalum compartment, pH 2 in the Prussian Blue compartment, 0.3 M H₂O₂, 2.0 M NaCl, and 0.05 M Dy(NO₃)₃, the cell produced an OCV of 724 mV and a peak power density of 0.283 mW/cm² at a current density of 0.8 mA/cm². These results demonstrate that meaningful electrochemical performance can be achieved in a dual-compartment H₂O₂ fuel cell without the use of precious metal catalysts and highlight electrolyte engineering as an effective strategy for improving cell output in this class of device. Full article

Electrodeposition of nanostructured metals often suffers from a trade-off between mechanical performance and efficiency. This study introduces ultranarrow slit-jet scanning electrodeposition (USJS-ECD), an additive-free technique employing a planar jet confined by a slit with opening width of <100 μm to scan the cathode. Numerical simulations coupling fluid flow and electric fields were conducted to optimize jet dynamics and scanning parameters. Experimental analyses reveal that USJS-ECD creates a highly localized, uniformly intensified energy field enabling direct fabrication of ultrahigh-strength nickel. The resulting deposits exhibit 98.82 wt% purity, an ultrafine grain size of 21.86 nm, and a mirror finish with surface roughness (Ra) of ~22 nm. Mechanical testing demonstrates a microhardness of 623 HV, a tensile strength of 756 MPa, and an elongation of 9.33%, achieving a superior strength-ductility synergy. Crucially, the deposition rate reaches 1.72 μm/min, significantly outperforming advanced ultrafine anode scanning electrodeposition (UAS-ECD) techniques. USJS-ECD presents a promising, efficient methodology for producing high-performance nanocrystalline metallic materials. Full article

The high energy consumption of water electrolysis is primarily limited by the sluggish oxygen evolution reaction (OER). Replacing the OER with thermodynamically favorable anodic reactions provides an effective strategy to improve energy efficiency. Among these reactions, the sulfide oxidation reaction (SOR) offers both low thermodynamic potential and environmental relevance. In this work, we develop a high-entropy metal sulfide catalyst, CuNiCoFeMnS, via a facile aqueous synthesis route, achieving homogeneous elemental dispersion and a highly disordered structure. The catalyst exhibits excellent SOR activity, delivering a low potential of 0.396 V to achieve a current density of 10 mA cm⁻². In addition, it enables a significant reduction of 1.05 V in cell voltage at 50 mA cm⁻² compared with conventional water electrolysis. Furthermore, by integrating solar energy, the system enables simultaneous upgrading of sulfide-containing wastewater and energy-efficient hydrogen production. These results demonstrate a promising pathway toward coupling waste remediation with sustainable hydrogen generation. Full article

The growing demand for efficient and sustainable energy storage systems has intensified research on advanced materials for lithium–ion batteries (LIBs). Gel-based synthesis routes—particularly polymeric and chelating gel techniques—have emerged as powerful methods for designing lithium–ion battery (LIB) anode materials with tailored microstructures, composition uniformity, and enhanced electrochemical performance. These methods facilitate the transformation of solution-phase precursors into homogeneous and finely structured materials, enabling precise tuning of physicochemical properties. This review provides a comprehensive overview of the fundamental principles of polymeric and chelate gel synthesis routes, highlighting their ability in controlling particle size, morphology, and phase purity. Their applicability to a wide range of anode materials, including transition metal oxides and silicon-based composites, is discussed. The manuscript highlights LIBs anode material developments via gel precursor chemistry, structure–property relationships, and future directions toward scalable and sustainable electrode manufacturing. Full article

Understanding lithium distribution and transport within Li-ion battery components is critical in improving battery longevity, safety and performance. This study investigates lithium concentration profiles across the interface of an aluminum-doped Li₇La₃Zr₂O₁₂ (Al-LLZO) solid electrolyte and a lithium metal anode using Nuclear Reaction Analysis (NRA), a non-destructive depth-profiling technique. The Al-LLZO electrolyte was synthesized via electrospinning, producing nanofibers, which were subsequently sintered into pellets of average thickness 380 µm. These pellets were integrated into a Li|Al-LLZO|NMC-111 half-cell and cycled at 0.1 C for 1, 3, and 10 cycles, indicating pronounced lithium accumulation at the electrolyte–anode interface. Using NRA, this study provided a clear pathway for better understanding lithium transport and interfacial behavior, by quantitatively measuring the lithium distribution at the Al-LLZO electrolyte–electrode interface, and to look at the changes at this interface over the battery cycles. Full article

This study focuses on a group of scanning electrochemical probe microscopies used to reveal the early stages of galvanic coupling corrosion reactions, based on the use of microelectrochemical sensors for measuring local potentials and currents associated with chemical reactions occurring at anodic and cathodic sites, and their correlation with results obtained with conventional electrochemical techniques. Although galvanic corrosion between dissimilar metals is generally analyzed by assuming that the anodic and cathodic half-cell processes occur in different metals, the use of microelectrochemical techniques reveals that the corrosion process is actually more heterogeneous. Cathodic activity is present in both metals, but to very different degrees. Anodic activity is also localized, as the surface of the more reactive metal is not fully available to undergo anodic dissolution. Because galvanic corrosion processes are heterogeneously distributed over the surface of the coupled materials, even in model systems, the identification of cathodic sites and reactions is often insufficient when monitored by conventional electrochemical methods. These observations are particularly relevant when corrosion protection measures aim to minimize or eliminate the activity of cathodic reaction sites. Full article

Faced with a global energy crisis and ecological degradation, overall water splitting (OWS) is a pivotal approach for renewable energy conversion and storage. However, its industrial application is hindered by the high energy barriers/sluggish kinetics of the anodic oxygen evolution reaction (OER), as well as the scarcity of precious metal catalysts limiting large-scale deployment. Herein, a cobalt-based layered double hydroxide (Co-LDH) was used as the precursor, and a multi-strategy synergistic modification (hydrothermal synthesis, Fe doping, sulfurization, and external magnetic field magnetization) was applied to fabricate the Fe-Co₃S₄-MS-20 min electrocatalyst. This strategy establishes Fe-Co bimetallic synergistic active centers, and magnetic treatment modulates the electron configuration of Fe 3d orbitals without changing the material’s lattice spacing or morphology. Structural characterizations and electrochemical measurements were used to investigate the effects of combined modifications on the catalyst’s phase structure, morphology, electronic structure, and trifunctional catalytic performance toward the hydrogen evolution reaction (HER), OER, and urea oxidation reaction (UOR). The Fe-Co₃S₄-MS-20 min catalyst exhibits a larger electrochemical active surface area, lower charge transfer resistance, and smaller Tafel slope in 1 M KOH, it achieves overpotentials of 165 mV for HER (10 mA·cm⁻²) and 310 mV for OER (100 mA·cm⁻²), along with superior UOR performance and long-term stability. In situ impedance and Raman spectroscopy confirm that magnetization accelerates charge transfer and promotes in situ reconstruction. Synergistic multi-strategy regulation optimizes the electronic structure of active centers, reducing electrocatalytic energy barriers. This work provides new insights into designing high-performance non-precious metal electrocatalysts and offers experimental support for external magnetic field regulation in electrocatalyst modification. Full article

At present, lithium lanthanum zirconate (LLZO) is regarded as one of the most promising solid-state electrolyte materials due to its high ionic conductivity (about 10⁻³ S/cm at room temperature), high chemical stability, and excellent chemical stability toward cathode materials and lithium metal anodes. However, there are several problems, such as poor interface contact with the lithium metal anode resulting in high interface impedance, a high sintering densification temperature (usually >1200 °C), a complex preparation process, and high cost. In recent years, researchers have conducted extensive studies on LLZO and achieved remarkable progress and results. This paper systematically reviews the research progress of LLZO’s structural characteristics, conductive mechanism, preparation methods, improvement strategies, and so on. Full article

A new finite element simulation methodology for analyzing the mechano-electrochemical effects of Al alloys with intermittent measurement and reconstructed boundary conditions is proposed. It enables the simulation of the coupled mechano-electrochemical effects within the entire elastoplastic range of Al alloys. The model’s accuracy was verified through measurements of galvanic current, coupled potential, and corrosion morphology. This study indicates that the non-uniform stress distribution on a metal surface results in inconsistent electrochemical properties, leading to the spontaneous formation of anodes and cathodes and facilitating galvanic corrosion. Regions with stress concentration act as anodes in the corrosion reaction, while other areas serve as cathodes. The electrolyte domain is approximately polarized to the same potential, but there are also minor differences between different regions. As the stress concentration gradually increases, the mixed potential decreases, leading to greater polarization and an accelerated corrosion reaction rate. The galvanic current and the coupled potential calculated by the model differ from the measured values by less than 15%. Moreover, the observed corrosion morphology is consistent with the calculated results, indicating that the model provides good predictions of coupled mechano-electrochemistry. Full article