A critical challenge for the application of direct ethanol fuel cells (DEFCs) lies in the sluggish kinetics of C─C cleavage. Herein, a significant portion of Ni is retained in the interior of nitric acid etched PtFeCoNi pod-like nanowires (PtFeCoNi-N) with incomplete voids/cavities due to anti-Kirkendall effect. The efficient electronic tuning toward surface Pt gives rise to the superior ethanol oxidation reaction (EOR) activity of 1.82 A mgPt -1 and 3.21mA cm-2, 4.80-fold and 5.10-fold improved relative to Pt/C, respectively. Strikingly, after chronoamperometric test of 50000s and 1500 consecutive potential cycles, 86.81% and 82.42% of the initial activity of PtFeCoNi-N are retained. Multiple spectroscopic characterizations reveal that the PtFeCoNi-N shows excellent selectivity toward C1 pathway even above 1.0V. The lowered Pt coordination related to less occupancy of antibonding states plays a crucial role for enhancement in activity and selectivity. The interfacial microenvironment balance between hydrogen-bonded H2O and free H2O contributes to H2O dissociation for CO* oxidation. Density functional theory elucidates the origin of anti-Kirkendall effect and the intimate electronic interaction with surface Pt that endows PtFeCoNi-N with superior inclination toward C1 pathway. This work presents a novel catalyst design strategy of reversing the dissolution of transition metals.

ABSTRACT While high‐nickel cathodes offer compelling energy density, their cycle life is severely compromised by transition metal (TM) dissolution and subsequent interfacial degradation at the anode. Herein, we engineer a fully biodegradable composite separator comprising poly(lactic acid) and poly(ethylene glycol) (PLA/PEG) to address these issues through multifunctional integration. The ether‐oxygen‐rich PEG chains not only effectively scavenge dissolved TM ions through strong Lewis acid‐base interactions and enhance interfacial ion transport, but also facilitate hydrolytic breakdown of the PLA matrix, collectively contributing to a self‐mediating interphase, while the mutually‐reinforced degradability of both polymers ensures environmental benignity. The Graphite || NCM811 full cell employing the PLA/PEG separator demonstrates exceptional cyclability, retaining 70.4% capacity after 2000 cycles at 5 C with a cathode loading of 10.56 mg cm −2 . This work presents a paradigm of eco‐adaptive separator design that concurrently enhances electrochemical durability and environmental sustainability.

Nickel-rich layered oxide cathodes (LiNi0.8Co0.1Mn0.1O2, NCM811) have shown great promise in high-energy-density lithium-ion batteries due to their high specific capacity. However, their practical application is severely hampered by structural instability, interfacial side reactions, and transition metal dissolution. To address this issue, in the present work, a highly polar polyimide containing sulfonyl moiety (named PI (6FOS)) is designed and utilized as a functional interfacial coating layer on NCM811 by copolymerizing 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) with 4,4'-oxidianiline (ODA) and 4,4'-diaminodiphenyl sulfone (DDS). The combination of high polar constant and superior interfacial stability of PI (6FOS) contributes to effective suppression of electrolyte decomposition and transition metal dissolution. The strong interactions between polar trifluoromethyl and sulfonyl groups in the molecular chain and NCM811 particles enhance interfacial stability and facilitate lithium-ion transport. As expected, the PI (6FOS)/NCM811 electrode exhibits excellent long-term cycling performance with a remarkable capacity retention of 94% over 100 cycles at 0.2 C and 83% over 300 cycles at 1 C within 2.5-4.3 V. Even under high-voltage conditions (4.7 V), it maintains 59% capacity retention after 300 cycles at 1 C. The PI (6FOS)/NCM811 electrode shows outstanding rate capability, with a discharge specific capacity of 140.3 mAh g-1 at 5 C. Meanwhile, the presence of the polyimide coating layer increases the thermal decomposition temperature of the cathode material and reduces heat generation. The perspective of the coating design strategy based on sulfonyl-containing polyimide modification offers a novel path toward high-stability cathodes for high-energy-density and high-safety lithium-ion batteries.

ABSTRACT Solid‐state lithium batteries (SSLBs) with lithium‐rich manganese‐based (LRM) cathodes and gel electrolyte offer a promising route toward high‐energy‐density electrochemical devices. However, high‐voltage operation causes cathode interface degradation via oxygen release and transition metal dissolution, while lithium metal anodes suffer from interfacial side reactions and uneven deposition. Herein, we propose a multifunctional additive based on a fluorophenyl scaffold, 3‐cyano‐5‐fluorophenylboronic acid (CFPBA), where tailored substituents synergistically stabilize both cathodic and anodic interfaces. The meta‐substituted boron electron‐deficient center mitigates oxygen release by trapping reactive oxygen species, while the cyano group suppresses transition metal dissolution via complexation, thereby cooperatively stabilizing the lattice oxygen and transition metal cations. Moreover, the introduction of the fluorine group promotes the generation of a LiF‐enriched SEI, enhancing lithium‐ion transport kinetics and suppressing lithium dendrite growth. Remarkably, the modified gel‐state SSLBs exhibit excellent cycling performance with 81.2% capacity retention over 400 cycles at 1C. Under high load cathode conditions, the 4.8 V LRM | Li pouch cell with a capacity of 2.5 Ah (∼467 Wh kg −1 based on the total mass of the cell) retains 91.7% capacity after 50 cycles. This work establishes a versatile additive‐engineering framework for high‐voltage SSLBs with prominent interfacial stability and prolonged cycling life.

This study quantitatively investigates the corrosion behavior of aluminum (Al1070) under salt water acetic acid test (SWAAT) conditions, focusing on the effects of chloride ions (Cl−) and acetic acid (CH3COOH) concentration on the pitting corrosion. Potentiodynamic polarization tests showed that increasing Cl− concentration caused a negative shift in corrosion potential (Ecorr) and an increase in corrosion current density (icorr), indicating accelerated passive film breakdown and enhanced pitting susceptibility. Immersion tests and SEM analysis revealed intensified surface discoloration, oxide formation, and crack propagation at higher Cl− levels, confirming localized dissolution. The effect of acetic acid was evaluated for concentrations ranging from 0 to 2000 µL L−1. Higher acetic acid levels lowered solution pH and slightly increased Ecorr and elevated icorr while reducing ΔE(Epit − Ecorr), indicating increased localized corrosion susceptibility. SEM and 3D XCT analyses showed increased pit density, corrosion loss, and pitting showed temporary pit coalescence at intermediate concentrations. Mechanistically, the acidic SWAAT environment (pH 2.8–3.0) positions aluminum in the active corrosion region. Cl− destabilizes the passive oxide layer, initiating pitting, while acetic acid promotes metal dissolution via hydrogen evolution reactions. Their combined action exerts a specific effect, accelerating localized corrosion through chemical oxide layer degradation. These results provide quantitative insights into aluminum corrosion under SWAAT conditions. They could inform the design of corrosion resistant materials and reliability assessments in industrial applications.

ABSTRACT Tungsten, a critical metal essential for high‐performance and emerging technologies, is traditionally extracted from scheelite through energy‐intensive, high‐temperature, and high‐pressure processes. This study presents an environmentally benign hydrometallurgical route for tungsten recovery from complex Hutti gold mine tailings using a dual organic leaching approach. Organic acids such as oxalic and citric acids were evaluated individually and in sequence to understand their leaching behavior and metal selectivity. The study briefly examines the leaching dynamics using oxalic acid and forms a base approach emphasizing the potential of employing a dual leaching aspect. Citric acid selectively dissolved impurity metals such as Fe, Ca, Mg, and Mn through complexation, while oxalic acid promoted tungsten dissolution via formation of soluble tungstate–oxalate species. The dual leaching approach affirms successful tungsten recovery (78.4%) with limited co‐dissolution of impurities (6.8% Fe, 0.5% Ca, 10.8% Mg, and 8.9% Mn) using 0.5 and 0.25 mol/L concentrations of citric acid and oxalic acid, respectively. The enhanced recovery is attributed to the preferential dissolution of the target metal in organic acids owing to their chelation ability, resulting in the formation of stable metal‐ligand complexes. The dual leaching aspect of the study was further validated through XRD analysis, peak intensity ratio determination, and quantitative analysis. Overall, the dual‐organic‐acid strategy provides a mild, selective, and sustainable alternative to conventional mineral‐acid leaching, advancing green extraction practices for tungsten recovery from low‐grade secondary resources.

Stabilizing Co-free Li-rich cathodes with LaF3 coating and ionic liquid electrolytes: A pathway to high-performance lithium-ion batteries.

Palladium, a non-toxic platinum-group metal, is widely used in catalysis, electronics, hydrogen storage, and chemical industries because of its excellent physical and chemical properties. However, given that the number of palladium-producing countries is limited, recycling is considered essential for ensuring a stable and sustainable global supply. Here, I describe a simple and efficient method for palladium recovery from electronic waste (e-waste) using Enterobacter oligotrophicus CCA6T. To clarify biomineralization capacity, the role of electron donors in modulating biomineralization capacity was examined. Findings showed that formic acid was the most effective donor, enhancing the relative recovery rate to 44% compared to 23% without electron donors. Transmission electron microscopy analysis revealed palladium particles (1–10 nm) distributed across the cell wall, periplasmic space and cytoplasm, confirming active biomineralization rather than passive biosorption. Moreover, based on a comparison with the biomineralization mechanism of Escherichia coli, the biomineralization mechanism of E. oligotrophicus CCA6T was estimated . Reaction parameters were then optimized by testing the effects of formic acid concentration, reaction temperature, and reaction pH. Under optimized conditions, the relative recovery rate exceeded 99% within 6 h using 40 mg/L palladium. When this method was applied to a metal dissolution solution prepared from e-waste , a recovery rate of 94% was achieved from trace concentrations (36 µg/L), and palladium loss from bacteria after the palladium recovery test was negligible (<0.01%). Taken together, these results demonstrate that biomineralization using E. oligotrophicus CCA6T could potentially be applied to the recovery of palladium from e-waste, particularly for trace-level concentrations where conventional methods are ineffective.

The depletion of natural resources remains a major global challenge, emphasizing the need to develop sustainable processes that enable both metal recovery and waste recycling. This study investigates the leaching of valuable metals from lead smelting slag using methanesulfonic acid (MSA), a biodegradable and environmentally benign reagent. Batch experiments were performed under different MSA concentrations (0.35–1.4 M) and temperatures (22–80 °C). Metal dissolution increased nearly linearly with acid concentration up to 1 M, with maximum recoveries after 60 min of 85% Zn, 64% Pb, 75% Cu, and 68% Fe. Copper dissolution was governed by the oxidation of Cu2S, while Fe leaching was affected by pH variations that promoted re-precipitation. Kinetic modeling indicated mixed chemical–diffusion control mechanisms, with activation energies of 22.6 kJ mol−1 for Zn and 31–33 kJ mol−1 for Pb, Cu, and Fe. Beyond efficient metal extraction, the process generated a leach residue with reduced concentrations of base metals and a mineralogical composition dominated by stable calcium-silicate phases, improving its potential suitability for reuse in construction or mining backfill applications. Overall, methanesulfonic acid proved to be an effective and sustainable lixiviant, combining high metal recovery with the generation of recyclable slag, thereby contributing to circular metallurgical practices.

Nickel-rich layered LiNixCoyMnzO2 (NCM, x 0.6) cathodes have been widely used for high-energy-density lithium-ion batteries (LIBs), delivering exceptional capacity 200 mAh g-1) and remarkable cost-efficiency. Nevertheless, structural degradation (e.g., oxygen vacancy formation, transition metal dissolution) and interfacial instability (side reactions) under high-voltage operation ( 4.3V) severely limit their cycle life. Recent advances demonstrate that precisely engineered surface coatings can synergistically address these limitations through suppressing parasitic reactions, stabilizing lattice frameworks, and enhancing Li+ transport kinetics. This review provides a multidimensional analysis of coating engineering for NCM cathodes, focusing on the mechanism insights, innovative designs, and synthesis route. Notably, this work emphasizes emerging opportunities within underexplored research areas, specifically artificial intelligence-enabled coating architectures and sustainable large-scale synthesis methodologies. By systematically integrating fundamental mechanistic insights with practical engineering perspectives, a robust framework to accelerate the utilization of NCM cathodes as ultra-stable and safe energy storage systems is established in this review.

The escalating production and use of lithium-ion batteries (LIBs) have led to a pressing need for efficient and sustainable methods for recycling valuable metals such as cobalt, nickel, manganese, and lithium from spent cathode materials. Traditional hydrometallurgical leaching approaches, based on mineral acids, face significant limitations, including high reagent consumption, secondary pollution, and poor selectivity. In recent years, deep eutectic solvents (DESs) and ionic liquids (ILs) have emerged as innovative, environmentally benign alternatives, offering tunable physicochemical properties, enhanced metal selectivity, and potential for reagent recycling. This review provides a comprehensive analysis of the current state and prospects of leaching LIB cathode materials using DES and ILs. We summarize the structural diversity and composition of common LIB cathodes, highlighting their implications for leaching strategies. The mechanisms, efficiency, and selectivity of metal dissolution in various DES- and IL-based systems are critically discussed, drawing on recent advances in both laboratory and real-sample studies. Special attention is given to the unique extraction mechanisms facilitated by complexation, acid–base, and redox interactions in DES and ILs, as well as to the effects of key operational parameters. A comparative analysis of DES- and IL-based leaching is presented, with discussion of their advantages, challenges, and industrial potential. While DES offers low toxicity, biodegradability, and cost-effectiveness, it may suffer from limited solubility or viscosity issues. Conversely, ILs provide remarkable tunability and metal selectivity but are often hampered by higher costs, viscosity, and environmental concerns. Finally, the review identifies critical bottlenecks in upscaling DES and IL leaching technologies, including long-term solvent stability, metal recovery purity, and economic viability. We also highlight research priorities that emphasize applying circular hydrometallurgy and life-cycle assessment to improve the sustainability of battery recycling.

Potassium pyrophosphate (K₄P₂O₇) completion fluid exhibits excellent chemical stability in high-temperature environments (up to 150 °C or above), making it suitable for deep-well and high-temperature reservoir operations. With its inherently alkaline nature (pH ≈ 9 –12), the fluid presents a corrosion mechanism distinct from the widely studied sweet and sour corrosion. Phosphate species (H₂PO₄⁻/HPO₄²⁻/PO₄³⁻) act as strong complexing agents, forming soluble complexes with Fe²⁺/Cr³⁺ and thereby accelerating metal dissolution, an effect that becomes more pronounced with increasing temperature. To investigate this issue, a series of corrosion tests were performed on s13Cr martensitic stainless steel (s13Cr SS, UNS S41500) in simulated completion fluid environments. In-situ electrochemical methods and surface characterization techniques revealed that both increased porosity and chemical composition variation contribute to the deterioration of the passive film. Competitive adsorption of phosphate species weakens the protective capability of the external film, while elevated temperatures promote the formation of Fe₃(PO₄)₂ owing to higher porosity. These processes further intensify HPO₄²⁻-induced porosity and ultimately lead to the degradation of corrosion resistance in s13Cr stainless steel, and subsequent cause the localized corrosion and induced high risk of SCC. The addition of potassium chromate (K₂CrO₄) effectively mitigates corrosion by enhancing passive film integrity, reducing corrosion rates, and preventing phosphate deposition.

LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode material has been increasingly applied in industry for lithium‐ion batteries owing to its high specific capacity. However, the quick capacity fade of these batteries, especially at high temperatures, remains a major technical issue to be resolved for practical applications. In this work, an aminotrisiloxane compound (HMTSN) as an electrolyte additive to enhance the cycling performance of NCM811 cells by constructing a robust cathode electrolyte interphase (CEI) on the cathode surface and scavenging corrosive acidic species in the electrolyte is designed and synthesized. The trisiloxane moiety in HMTSN forms a homogeneous CEI with a higher Young's modulus in comparison with the baseline electrolyte without 0.5 wt% HMTSN additive. Additionally, the transition metals dissolution and the Li + /Ni 2+ mixing in the NCM811 is significantly inhibited due to the formed CEI and removal of acidic species, thus improved electrochemical performance for NCM811/graphite coin cell, especially the rate capability at 10C. The NCM811/SiC pouch cell demonstrates superior high‐temperature cycling stability at 55 °C, showing a higher capacity retention of 75% after 500 cycles at 0.5C, far exceeding 42% for of the baseline.

Oxygen release is a major issue associated with layer-structured metal oxide cathodes in lithium batteries, which can further cause a series of problems, such as irreversible phase transition, microcracking, and electrolyte decomposition. Eventually, these issues jointly result in cell performance degradation and safety hazards. Thus, it is very significant to tackle oxygen release for achieving long-term stable cyclability, but very challenging. Although intensive efforts have been invested to date, there still lacks a feasible solution. In this study, nanoscale ZrS2 coatings are applied on prefabricated LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes directly via atomic layer deposition (ALD). Very encouragingly, we reveal that this ALD-deposited conformal ZrS2 nanocoating can serve as an exceptional oxygen scavenger and then convert into a stable sulfate (Zr(SO4)2) coating. Such an in situ conversion is very beneficial and effective for protecting the electrolyte from decomposition. In addition, the resultant Zr(SO4)2 coating further inhibits undesirable reactions, stabilizes the interface between NMC811 and the electrolyte, suppresses microcracking, mitigates transition metal dissolution, and maintains the structural stability of the NMC811 cathode. Consequently, the ZrS2-coated NMC811 cathode has demonstrated extraordinary performance. Thus, this study advances the understanding of interface engineering while paving a new technical pathway for commercializing NMC811 cathodes.

Reversible metal electrodeposition devices (RMEDs) operate through electrochemically controlled metal deposition and dissolution to modulate optical properties, making them a promising platform for smart windows and adaptive displays. Unlike traditional electrochromic devices that rely on ion insertion or organic redox processes, this reversible metal deposition/dissolution mechanism eliminates the need for complex multilayer structures, offering superior optical and thermal management through reflection-based light control. Silver-based RMEDs have successfully demonstrated multicolor switching capabilities; however, their high material costs limit their practical use. Copper, being abundant and having lower electrodeposition potentials, offers a compelling alternative; yet, previous copper-based devices achieved only monochromatic operation due to limited control over nucleation and growth. Here, we present a breakthrough copper-based RMED that overcomes these limitations with a dual-electrode design combining indium tin oxide (ITO) nanoparticle-decorated ITO (NITO) and smooth flat ITO (FITO) electrodes. This approach enables reversible switching among four distinct optical states: transparent, blue, red, and mirror, marking the first demonstration of achieving both blue and red coloration on a single electrode in a copper-based system. Adjusted voltage protocols (constant-voltage for blue, step-voltage for red) induce wavelength-specific localized surface plasmon resonance (LSPR) absorption at 700 and 550 nm, respectively, while anodic deposition on the smooth electrode produces broadband reflection for the mirror state. The device exhibits high optical modulation across all states (ΔT from 55.8 to 72.2%), with substantial color differences (ΔE values of 33.7 and 42.8 for the blue and red states, respectively) that ensure distinct visual perception. Consistent coloration times (∼10 s) and practical bleaching times (9.8-17.9 s) support responsive switching, making it suitable for smart window applications. The device demonstrates moderate cycling stability with retention exceeding 80% after 100 cycles across all optical states. These results establish copper-based RMEDs as a viable and cost-effective approach for multicolor electrochromic technologies in energy-efficient buildings and adaptive optical systems.

Lithium-ion batteries (LIBs) have been widely applied in electric vehicles, smart grids, and other fields due to their high energy density and long cycle life. However, the flammability of conventional carbonate-based electrolytes poses significant safety risks and hinders the large-scale deployment of high-energy-density batteries. Herein, we propose a non-flammable carbonate-based local high-concentration electrolyte (LHCE) composed of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)/fluorinated ethylene carbonate (FEC)/1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE). This formulation replaces highly flammable conventional solvents with FEC and highly fluorinated TTE, substantially reducing fire hazards. The electrolyte exhibits an electrochemical window up to 5.5 V. Synergistic interactions between TFSI- anions and FEC facilitate the formation of a robust, LiF-rich solid electrolyte interphase (SEI) on the graphite (Gr) anode and an effective cathode-electrolyte interphase (CEI) on the high-voltage LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode, suppressing structural degradation and transition metal dissolution. Consequently, an NCM811∥Gr full battery using the LHCE demonstrates superior cyclability, with a capacity loss of less than 8% over 200 cycles at a high cutoff voltage of 4.5 V and an average coulombic efficiency (CE) of 99.9%. This work provides a promising electrolyte design for stable and safe high-voltage LIBs, offering potential guidance for advanced battery systems.

Abstract High‐voltage spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) is a promising lithium‐ion battery cathode due to its low cost and environmental compatibility. However, high‐voltage operation triggers phase transition and transition metal dissolution, causing irreversible active material loss. Dissolved metals further migrate to the anode, inducing harmful crosstalk that accelerates failure. These degradation mechanisms fundamentally limit high‐energy, safe battery development. Here, a bulk/interfacial strategy involving an architected doping gradient and near‐surface reconstruction is proposed from the structure/function relation of LNMO. Specifically, uniform incorporation of Co stabilizes the 16 c /16 d sites strategically, facilitating solid‐solution reactions while preserving structural stability at elevated temperatures. Simultaneously, surface‐gradient Na and near‐surface B slightly‐doping to in situ derivation a Na 2 B 4 O 7 coating—a fast‐ion conductor that functions as a preferential sacrificial scavenger. This dual‐functional structure enables rapid Li + conduction while inhibiting electrolyte decomposition and HF attack. Notably, the crosstalk effect related to Mn‐ion migration is effectively restricted during harsh 45 °C/4.95 V cycling. Consequently, the modified cathode (NCB‐LNMO) retains an ultrathin, dense, and homogeneous cathode electrolyte interfaces (CEI)/solid electrolyte interphas (SEI) architecture, achieving an exceptional capacity retention of 94.5% after 300 cycles at 45 °C. This study highlights that the bulk/interface engineering establishes a blueprint for LNMO‐based LIBs with enhanced cycle life and safety metrics.

Revealing the atomic-scale mechanism of organic corrosion inhibitors in suppressing anodic dissolution of metals via ab initio molecular dynamics and metadynamics simulations: A case study of sorbitol on aluminum

Fe-Co dual-sites p-d orbital hybridization: Electronic restructuring for accelerated oxygen evolution kinetics.

In the pursuit of the development of safe energy storage devices, aqueous zinc metal batteries have garnered incredible attention due to their non-flammable nature and high energy densities. However, they suffer from severe complicated degradations induced by dendrite formation, hydrogen evolution reaction, transition metal dissolution, and their crosstalk effect. Herein, membranes are designed and engineered for high mechanical strength, Zn2+ selectivity, and hydrophobicity to simultaneously address the complex degradations. The prevention of dendrite formation and crosstalk-induced side reactions results in high reversibility of Zn metal anodes with a high average CE of 99.73% and an excellent cycle life in full cells with a capacity retention of 88.87% after 1000 cycles. This result highlights the importance of crosstalk prevention in the separator and offers the design principle of novel membranes for aqueous Zn metal batteries, advancing toward commercial level without requiring major modifications to the overall system.