Achieving sufficient electrochemical activity in redox-active organic materials relies on incorporating sufficient conductive carbon to establish a percolating network between the active phase and the current collector. This network is...

Instability at the electrode-electrolyte interface during metal electrodeposition promotes non-uniform growth and the formation of dendritic structures, which adversely affect electrochemical performance in various systems, particularly batteries. Because electrodeposition occurs at embedded electrode-electrolyte interfaces, which are moving and deforming boundaries, direct experimental investigation and quantitative comparison with computational models is challenging. In this work, a computational model of the electrodeposition interface is validated using a planar experimental system that enables direct imaging of silver electrodeposition and approximates the geometry of a two-dimensional simulation. While dendritic growth is often investigated qualitatively, little work has been done to quantitatively measure dendritic growth, particularly at nanometer scales. In this study, quantitative parameters for dendritic growth, including electrodeposition density, dendrite branch thickness, and dendrite aspect ratio, are defined and used to validate computational results for silver electrodeposition with results from experimental electrodeposition. The sensitivity of the computational system is evaluated by studying the effects of variations in operating and material parameters on dendritic growth, using the established quantitative parameters. Finally, the computational model is used to explore stable electrodeposition regimes that are challenging to attain experimentally.

Hybrid electrolyte solutions composed of water and water-miscible organic solvents have gained attention for their extended electrochemical stability window, nonflammability, high ionic conductivity, and cost-effectiveness. Among them, dimethyl sulfoxide (DMSO) is a particularly attractive cosolvent due to its high dielectric constant, strong hydrogen-bonding ability, low volatility, and excellent chemical stability. When mixed with water, DMSO disrupts the native hydrogen-bond network, significantly altering key physicochemical properties such as viscosity, density, dielectric constant, and water activity─all of which are highly sensitive to composition. Despite their potential, the behavior of water-DMSO electrolytes under high salt concentrations and their effects on electrode performance remain underexplored. Here, we investigated nearly saturated LiClO4 solutions in water-DMSO mixtures, combining electrochemical testing with NMR, Raman spectroscopies, and theoretical modeling to reveal solvation structures and ion-solvent interactions. We further evaluated how these electrolyte solution compositions impact the electrochemical performance of LiMn2O4 cathodes and TiO2 anodes. These insights highlight the promise of DMSO-based hybrid electrolyte solutions for advancing safe and high-performance aqueous lithium battery technologies.

Zinc-bromine (Zn-Br2) batteries represent a promising aqueous energy storage technology, yet their widespread deployment is hindered by the uncontrolled diffusion of molecular bromine from the cathode side, leading to severe self-discharge and capacity fading. Here, we demonstrate an effective strategy to mitigate bromine crossover by employing gemini-type bromine complexing agents (BCAs) impregnated into porous carbon hosts in their oily phase. This approach facilitates the in situ conversion of bromine into a water-immiscible polybromide BCA phase, thereby confining the active species within the electrode structure. The presence of aromatic linkers in the gemini BCA molecules significantly enhance their retention in the carbon network, most likely through π-π stacking interactions with the carbon framework. Moreover, controlled discharge protocols enabled preferential nucleation of polybromide domains within the confined pore environment, further improving the self-discharge stability of the system. As a result, the Zn-Br2 cells incorporating gemini-type BCAs exhibited suppressed bromine crossover, enhanced coulombic efficiency, and superior cycling durability compared to conventional systems. This work provides mechanistic insights and practical guidelines for the rational design of molecular complexants and electrode architectures for next-generation Zn-Br2 batteries.

The pursuit of sustainable energy storage beyond lithium-ion batteries has intensified interest in aqueous multivalent-ion systems. Among them, manganese-based batteries stand out owing to Mn's natural abundance, high theoretical capacity, and low redox potential (-1.19 V vs. SHE), which enables higher operating voltages than Zn-based counterparts. Here, we report a pre-intercalated manganese vanadate cathode, Mn0 & sdot;54V3O8 (MnVO), that delivers 376 mAh g- 1 at 0.4 A g- 1 with 65.7 % capacity retention after 2000 cycles. Structural, spectroscopic, and computational analyses reveal a unique Mn2+/H+ co-insertion mechanism, in which preintercalated Mn ions act as structural pillars to expand interlayer spacing, stabilize the framework, and create enlarged diffusion channels. This stabilizing effect lowers the proton migration barrier (0.126 eV), enabling proton-dominant fast kinetics while maintaining lattice robustness. When paired with a Mn metal anode, MnVO achieves an operating voltage of 1.2 V, markedly higher than Zn-based analogues. Although interfacial instability from hydrogen evolution and Mn(OH)2 formation remains a challenge, this study establishes high-degree preintercalation as a powerful design principle for intrinsically safe, high-voltage, and sustainable Mn-based hybrid aqueous batteries.

Iron-based batteries are attracting growing attention as sustainable and cost-effective systems for large-scale energy storage. Iron offers key advantages in aqueous environments, including natural abundance, high theoretical capacity, and environmental safety. However, the practical deployment of Fe-based batteries is hindered by parasitic hydrogen evolution, dendritic Fe deposition, and the narrow electrochemical window governed by the Fe2+/Fe3+ redox couple. To address these intrinsic challenges, we introduce a new cell design that employs an anion-exchange membrane (AEM) to separate the Fe anode from the catholyte. The AEM selectively conducts anions while blocking Fe2+ migration toward the cathode compartment, effectively preventing cross-contamination. This configuration enables the Fe anode to be coupled with a wide range of aqueous cathodes without mutual interference, thereby broadening the design flexibility of iron-based systems. Using concentrated LiCl or NaCl electrolytes as the catholyte and mixed FeCl2-LiCl/NaCl solutions as the anolyte, we demonstrate stable operation of electrochemical cells composed of Fe anodes and LiMn2O4 or NiFe(CN)6 cathodes. These systems deliver a capacity of 120 and 60 mAh g-1, respectively, based on the cathode mass. We believe that this newly developed concept provides a practical route to stabilize iron electrochemistry in aqueous media, offering a platform for the design of scalable, low-cost, and environmentally benign energy storage technologies suitable for grid applications.

The pursuit of sustainable energy storage beyond lithium-ion batteries has intensified interest in aqueous multivalent-ion systems. Among them, manganese-based batteries stand out owing to Mn's natural abundance, high theoretical capacity, and low redox potential (−1.19 V vs. SHE), which enables higher operating voltages than Zn-based counterparts. Here, we report a pre-intercalated manganese vanadate cathode, Mn0·54V3O8 (MnVO), that delivers 376 mAh g−1 at 0.4 A g−1 with 65.7 % capacity retention after 2000 cycles. Structural, spectroscopic, and computational analyses reveal a unique Mn2+/H+ co-insertion mechanism, in which pre-intercalated Mn ions act as structural pillars to expand interlayer spacing, stabilize the framework, and create enlarged diffusion channels. This stabilizing effect lowers the proton migration barrier (0.126 eV), enabling proton-dominant fast kinetics while maintaining lattice robustness. When paired with a Mn metal anode, MnVO achieves an operating voltage of 1.2 V, markedly higher than Zn-based analogues. Although interfacial instability from hydrogen evolution and Mn(OH)2 formation remains a challenge, this study establishes high-degree pre-intercalation as a powerful design principle for intrinsically safe, high-voltage, and sustainable Mn-based hybrid aqueous batteries.

Abstract Ceramic nanoparticles incorporated into solid polymer electrolytes have been reported to both enhance and suppress ionic conductivity, but the origins of these effects remain unclear due to difficulties in isolating interfacial phenomena in disordered bulk systems. Here, we characterize ion transport in ultrathin films of poly(ethylene oxide)–lithium bis(trifluoromethanesulfonyl)imide on silica and employ analytical modeling to elucidate how interfaces might control thickness-dependent behavior. Ionic conductivity is suppressed for the thinnest films at all salt concentrations and temperatures, though modest enhancement appears in some films at low salt concentration. The extent of modulation, however, varies with concentration alone. A modified Vogel–Fulcher–Tammann model incorporating both substrate and free-interface effects on polymer dynamics best captures the observed behavior, outperforming models based on nonconducting layers, interfacial salt partitioning, or substrate-only interface effects. This indicates that both inorganic surfaces and free interfaces can substantially influence polymer mobility and conductivity, suggesting that strategies to optimize composite polymer electrolytes should address the coupled behavior of interfacial polymer dynamics.

The development of highly stable coatings on iron is essential for mitigating corrosion formation. Herein, it is demonstrated that a self-assembled monolayer of N-Heterocyclic Carbene (NHC) can be electrodeposited on iron foil and function as a binder for a secondary, crosslinked polymer network coating. The dual layer coating, constructed of a monolayer of NHCs and a polymer film, as a primary and a secondary coating, respectively, effectively preventes corrosion formation with a protective efficiency of 99.6 ± 0.2 %, as determined by polarization measurements in 3.5 wt.% NaCl solution. Spectroscopic analysis identified the formation of a chemical interaction between the NHC monolayer and the polymer film. The strong anchoring of NHC to iron along with its chemical interaction with the polymer film induced high stability and durability of the dual-layer coating to effectively protect the coated iron from corrosion formation.

Protein aggregation into insoluble amyloid-like fibrils is implicated in a wide range of diseases and understanding its nucleation process is a key for mechanistic insights and advancing therapeutics. The electronic charge of the amyloidogenic monomers significantly influences their self-assembly process. However, the impact of electron spin interactions between monomers on amyloid nucleation has not been considered yet. Here, we studied amyloid formation on magnetic substrates using Scanning Electron Microscopy (SEM), fluorescence microscopy, and Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) Spectroscopy. We observed a preferred magnetization orientation of the ferromagnetic layer for fibril formation, leading to twice as many and significantly longer fibrils (up to 20 times) compared to the opposite magnetization orientation. This preference is related to monomer chirality. Additionally, fibril structure varied with substrate magnetization orientation. Our findings suggest a transient spin polarization in monomers during self-assembly, driven by the Chiral Induced Spin Selectivity (CISS) effect. These effects are consistent for various molecule length scales, from A-beta polypeptide to dipeptides and single amino acids, indicating a fundamental spin-based dependence on biomolecular aggregation that could be applied in novel therapeutic interventions targeted for amyloid-related diseases.

Prussian blue analogues (PBA) cathodes are emerging as promising electrode materials for post-Li batteries due to their open framework, high theoretical capacity, and fast ion diffusion channels. Their large interstitial sites facilitate the reversible intercalation of both small and bulky cations, enabling efficient charge storage. These interstitial spaces, however, can also accommodate water molecules, which significantly influence the charging mechanism and, consequently, the electrochemical performance of PBA. Since water is nonelectroactive at the working potential of PBA cathodes, monitoring the dynamics of H2O during charging is a challenging task. As a result, a comprehensive understanding of its contribution to the electrochemical behavior of PBA is still lacking. To address this issue, electrochemical quartz crystal microbalance with dissipation monitoring is employed to investigate NiPBA electrodes during the insertion/extraction of Na+, K+, and Cs+. This study is further supported by systematic electrochemical analysis in practical battery configurations and advanced X-ray diffraction measurements, providing deeper insights into the cation-water dynamics in PBA electrodes.

Protein aggregation into amyloid fibrils is central to numerous diseases, yet the role of electron spin interactions during nucleation and self-assembly remains unexplored. We investigated amyloid formation of A-β(1-42) polypeptide, implicated in Alzheimer's disease, and its smaller recognition motifs on ferromagnetic substrates. We observed a strong dependence of fibril formation dynamics on the substrate's magnetization orientation using electron and fluorescence microscopy. Specifically, one magnetization orientation yielded approximately twice as many and significantly longer (up to 20-fold) fibrils compared with the opposite orientation, a preference that flipped with the opposite monomer chirality. Furthermore, ATR-FTIR detected structural variations in the fibril structure, depending on the substrate magnetization. These findings suggest that transient spin polarization of the monomers during self-assembly, potentially driven by the Chiral-Induced Spin Selectivity (CISS) effect, plays a critical role in amyloid assembly dynamics. The consistency of these effects across different molecule length scales suggests a fundamental spin-based influence on biomolecular aggregation. This insight may have implications for therapeutic strategies, including the use of spin-polarized magnetic nanoparticles to selectively modulate amyloid formation in neurodegenerative diseases and the integration of spin-selective interfaces in dialysis systems to mitigate dialysis-related amyloidosis.

The stability of electrode materials in aqueous environments presents a significant challenge for the long-term performance of energy storage systems, particularly when operating at potentials that promote water electrolysis. Many electrode materials undergo spontaneous self-discharge, resulting in a gradual loss of stored charge. While previous studies have shown that metallic and inorganic electrodes in aqueous solutions can experience significant self-discharge, much less is known about this phenomenon in organic electrodes. To bridge this gap, this study investigates the self-discharge behavior of polyimide (PI)-based electrodes, focusing on 1,4,5,8-naphthalenetetracarboxylic dianhydride-derived polyimide (PNTCDA) in aqueous electrolyte solutions. Through a systematic evaluation of charge loss, we demonstrate that while water reduction primarily drives reversible self-discharge, it also indirectly contributes to irreversible capacity loss by generating reactive species and conditions that accelerate the hydrolytic degradation of the polymeric structure. These processes are particularly pronounced when the anode material is in its electrochemically reduced state at low potentials. Comparisons with nonaqueous systems reveal that even small amounts of water can significantly accelerate capacity loss, underscoring the susceptibility of organic-based electrodes to instability when operating within potential windows where water is reduced. These findings highlight the critical need for strategies to mitigate both reversible self-discharge and irreversible degradation processes in aqueous battery systems.

Solid polymer electrolytes (SPEs) can enable safer and more energy-dense Li metal batteries, yet their compatibility with high-voltage cathodes remains a key challenge. In this study, we systematically investigate the degradation mechanisms of poly(ethylene oxide)-based SPEs paired with Li nickel manganese cobalt oxide (NMC) cathodes. While stable cycling is observed with low-voltage Li iron phosphate (LFP) cathodes, NMC|SPE|Li cells exhibit severe capacity fading, which becomes increasingly pronounced at higher cutoff voltages. Electrochemical and structural analyses reveal that this degradation is not primarily due to Al dissolution or bulk polymer oxidation but instead arises from increased charge-transfer resistance and morphological changes within the cathode. Rate-dependent cycling reveals that a significant portion of the lost capacity is recoverable at low current, indicating kinetic limitations, while the remaining loss is irreversible and linked to structural degradation of the cathode. Comparative experiments with liquid electrolyte-based cells at 70 degrees C reveal degradation features similar to those observed in SPE-based cells, indicating that the dominant failure mechanisms arise under combined thermal and electrochemical oxidation stress rather than from polymer-specific chemistry. These findings emphasize the need for thermally and interfacially robust SPE systems to support stable high-voltage operation in solid-state Li metal batteries.

Achieving high capacity, long-term stability, and fast charge-discharge capability remains a central challenge in the development of advanced anode materials for lithium-ion batteries. In this work, we present nickel vanadium oxyphosphide (NVOP) nanosheets synthesized via controlled thermal phosphorization of NiV-layered double hydroxide (NiV-LDH). The resulting multiphase structure, composed of conductive Ni2P and redox-active vanadium oxides, delivers an initial discharge capacity of 1345 mAh/g and retains 442 mAh/g after 200 cycles at 0.1 A/g, with Coulombic efficiency stabilizing near 99.5%. NVOP also demonstrates excellent rate performance, maintaining 359 mAh/g at a high current density of 1.0 A/g. Electrochemical and structural characterization suggest that the improved cycling stability and rate capability may stem from the multiphase architecture, which integrates conductive and redox-active components within a porous nanosheet framework. These findings underscore the potential of direct phosphorization of mixed-metal layered hydroxide precursors as an effective strategy for constructing high-performance, durable anode materials for next-generation lithium-ion batteries.

The reversible electrodeposition of iron metal in aqueous electrolytes is a promising strategy for enabling cost-effective, large-scale aqueous rechargeable batteries. However, its practical viability is hindered by parasitic side reactions, particularly the hydrogen evolution reaction (HER), which lowers coulombic efficiency, and by the instability of deposited iron, leading to corrosion, capacity loss, and reduced cycle life. This study investigates the impact of three distinct ferrous-based electrolytes-sulfate (FeSO4), chloride (FeCl2), and trifluoromethane sulfonate (Fe(OTf)2)-on the reversible deposition behavior and passivation dynamics of iron metal anodes. Surface analysis reveals that electrolyte composition critically influences passivation layer formation, directly affecting stability and efficiency. FeSO4 and Fe(OTf)2 generate compact, iron-oxide/hydroxide-rich films that suppress hydrogen evolution, resist corrosion, and deliver high coulombic efficiencies during cycling. Notably, Fe(OTf)2 is especially effective at stabilizing the electrodeposited iron metal during long-term storage, exhibiting minimal self-discharge behavior. Conversely, FeCl2 leads to inadequate passivation, resulting in lower efficiency of electrodeposition and rapid loss of plated iron due to self-discharge. While increasing current density and electrolyte concentration can reduce water activity and improve deposition efficiency through kinetic regulation, we show that a stable, hydrated solid-electrolyte interphase is crucial for long-term corrosion protection and the durability of iron anodes in aqueous batteries.

Aqueous batteries are an emerging next-generation technology for large-scale energy storage. Among various metal-ion systems, manganese-based batteries have attracted significant interest due to their superior theoretical energy density over zinc-based battery systems. This study demonstrates oxygen vacancy-engineered vanadium oxide (V2O4.85) as a high-performance cathode material for aqueous manganese metal batteries. The V2O4.85 cathode had a discharge capacity of 212.6 mAh g(-1) at 0.1 A g(-1), retaining 89.5% capacity after 500 cycles. Oxygen vacancies enhanced ion diffusion and reduced migration barriers, facilitating both Mn2+ and H+ ion intercalation. Proton intercalation dominated charge storage, forming Mn(OH)(2) layers, whereas Mn2+ contributed to surface-limited reactions. Furthermore, manganese metal batteries had a significantly higher operating voltage than that of aqueous zinc battery systems. Despite challenges with hydrogen evolution reactions at the Mn metal anode, this study underscores the potential of manganese batteries for future energy storage systems.

Magnesium-ion batteries (MIBs) are promising candidates for lithium-ion batteries because of their abundance, non-toxicity, and favorable electrochemical properties. This review explores the reaction mechanisms and electrochemical characteristics of Mg-alloy anode materials. While Mg metal anodes provide high volumetric capacity and dendrite-free electrodeposition, their practical application is hindered by challenges such as sluggish Mg²⁺ ion diffusion and electrolyte compatibility. Alloy-type anodes that incorporate groups XIII, XIV, and XV elements have the potential to overcome these limitations. We review various Mg alloys, emphasizing their alloying/dealloying reaction mechanisms, their theoretical capacities, and the practical aspects of MIBs. Furthermore, we discuss the influence of the electrolyte composition on the reversibility and efficiency of these alloy anodes. Emphasis is placed on overcoming current limitations through innovative materials and structural engineering. This review concludes with perspectives on future research directions aimed at enhancing the performance and commercial viability of Mg alloy anodes and contributing to the development of high-capacity, safe, and cost-effective energy storage systems.

Static Zn-Br2 batteries are considered an attractive option for cost-effective and high-capacity systems for large energy storage. Yet, the corrosive nature of the Zn-Br2 electrolytes entails a careful selection of all cells' ingredients to avoid rapid degradation of the batteries upon cycling. Thanks to their high chemical resistance and excellent conductivity, carbonaceous electrodes are typically utilized as current collectors for the cathode side, while thin Zn or Ti foils are most widely used as the anodes' current collectors. However, these metals tend to corrode fast, thus undermining the desirable performance of the cells as durable and stable rechargeable batteries. We demonstrate the effective utilization of carbon nanotubes (CNT) films as highly stable anode current collector for Zn-Br2 batteries. Dispersion of the CNT beforehand in slurries containing anionic, cationic, or neutral surfactants yielded distinct chemical and physical characteristics of these carbonaceous electrodes. This, in turn, led to significant differences in the morphology of the deposited Zn, consequently affecting the electrochemical performance of the Zn anodes. These findings provide insight into the interactions between Zn cations and the surface of CNTs, offering opportunities for further surface modifications of CNTs as effective anodes' substrates for Zn-Br2 batteries.