Dynamic hydrogen bond networks are integral to enzymatic catalysis, enabling efficient substrate polarization, intermediate stabilization, and rapid active-site turnover. However, translating such adaptive features into synthetic systems at the nanoscale presents a significant challenge. Here, we report a rationally designed Fe-containing metal-organic framework (MOF), 2,5OH-MIL-101(Fe), derived from MIL-101(Fe), that mimics enzyme-like hydrogen-bond dynamics for efficient hydrogen peroxide (H2O2) activation. By site-specific hydroxyl functionalization of terephthalate linkers, 2,5OH-MIL-101(Fe) forms a confined hydrogen-bond network around FeO6 centers that stabilizes H2O2-derived intermediates through O-H···O interactions and promotes O-O bond activation. This network subsequently polarizes electrons through directional hydrogen bond interactions and ultimately facilitates H2O desorption via reversible bond switching. These nanostructured interactions continuously regenerate Fe active sites, leading to a 94.1-fold enhancement in peroxidase-like activity compared to conventional ferroferric oxide nanoparticles. The catalyst demonstrates robust, selective, and sensitive H2O2 activation within a physiologically relevant concentration range (10-1000 μM). This work demonstrates hydrogen bond network engineering in MOFs as a promising approach for creating adaptive catalysts that combine the precision of enzymes with the stability of nanomaterials, advancing bioinspired heterogeneous catalysis.
ABSTRACT Sodium‐ion batteries (SIBs) are promising for low‐temperature applications compared with commercial lithium‐ion batteries, because of the weaker solvation and higher conductivity of Na+ in electrolytes. However, the large size of Na+ leads to slow ionic transport and sluggish reaction kinetics in the electrodes, which is more severe after the lattice shrinks under low temperatures. Herein, a conjugated coordination polymer (CCP) is reported as a cathode for low‐temperature SIBs, by using naphthazarin (DHNQ) as the ligands and Ni2+ as the metal centers. Benefiting from the π‐d conjugation, the Ni‐DHNQ exhibits a high electrical conductivity of 69.7 mS/m and maintains both structural integrity and efficient electron and ion transport even at −40°C. These characteristics collectively enhance the reaction kinetics and cycling stability. The Ni‐DHNQ cathode enables ultrafast charging to 52% state‐of‐charge (SOC) in 90 s and exhibits an ultralow capacity decay rate of 0.0028% per cycle over 5000 cycles. When paired with an organic anode, the pouch full‐cell could reach 87% of its SOC even at −40°C, far higher than the commercial lithium‐ion batteries (12%) and reported alkali‐metal‐ion batteries. This work demonstrates the promise of CCPs for high‐performance sustainable energy storage under extreme conditions.
Efficient and cost-effective catalysts are essential to drive the oxygen evolution reaction (OER) in sustainable hydrogen production through water splitting, especially in seawater electrolyte. Here, Ce and S co-doped FeOOH nanosheets grown on nickel foam (CeS-FeOOH) are fabricated. Benefiting from the co-doping of Ce and S, the CeS-FeOOH catalyst has efficient charge redistribution and sufficient solid-liquid-gas interfaces. As expected, the CeS-FeOOH catalyst exhibits excellent OER activity, requiring overpotentials of 248 and 273 mV to achieve a current density of 10 mA cm(-2) in alkaline water and alkaline seawater electrolytes outperforming the commercial IrO2 catalyst, as well as superior stability. Meanwhile, the Faradaic efficiency of the CeS-FeOOH catalyst is still greater than 96.3% in alkaline seawater electrolyte. This work provides a new approach for the exploration of highly activity, efficient, and stable OER electrocatalyst for electrolysis of alkaline seawater.
Room-temperature sodium-sulfur (RT Na-S) batteries are promising candidates for large-scale energy storage owing to their high energy density and low cost, yet their practical deployment is hindered by sluggish sulfur redox kinetics and severe polysulfide shuttling. Here, guided by density functional theory (DFT) calculations, we develop a class of axially oxygen-coordinated ferromagnetic single-atom catalysts (SACs) with enhanced spin polarization to accelerate sulfur conversion. Among Fe-, Co-, and Ni-based SACs, Co-N2O3 is theoretically identified as the most effective configuration, featuring an optimized electronic structure with a minimal energy offset (0.26 eV) between the Co d-band and S p-band centers, which facilitates Na+ diffusion and lowers the activation barrier for polysulfide conversion. Experimentally, Co-N2O3 atoms anchored on hollow mesoporous carbon spheres (Co-N2O3@MCS) exhibit outstanding catalytic activity as the sulfur host, achieving an ultrahigh rate capability (330.5 mAh g-1 at 10 A g-1) and excellent durability over 600 cycles at 1 A g-1. In situ characterizations reveal that the enhanced ferromagnetism effectively suppresses polysulfide shuttling, underscoring the crucial role of coordination-engineered spin polarization in boosting the redox kinetics of RT Na-S batteries.
Manganese-based Prussian blue analogues (MnPBAs) are attractive cathodes for sodium-ion batteries (SIBs) due to their high operating voltage, low cost, and sustainability. However, their practical deployment is limited by rapid capacity decay caused by Jahn-Teller distortion and phase-transition-induced lattice strain, which trigger Mn dissolution and structural collapse during cycling. Herein, we introduce a surface Cu concentration-gradient-doped MnPBA (Cu@MnPBA) synthesized via a two-step coprecipitation strategy to stabilize the MnPBA framework while preserving high capacity. A ∼200 nm Cu-gradient surface layer effectively suppresses Jahn-Teller distortion, reduces lattice strain, and inhibits Mn dissolution, while an outer ∼10 nm Cu-rich amorphous layer enhances Na+ surface diffusion and suppresses interfacial side reactions. Unlike conventional coating strategies, the gradient-doping architecture eliminates interfacial mismatch, ensuring robust structural integrity during prolonged cycling. As a result, Cu@MnPBA delivers a high specific capacity of 143.9 mAh g-1 and retains 78% of its capacity after 500 cycles at 100 mA g-1. When paired with a hard carbon anode in a pouch cell configuration, the system maintains 75% capacity after 3000 cycles, demonstrating exceptional durability under practical operating conditions. This work establishes gradient surface doping as an effective design principle for realizing high-capacity, long-life Prussian blue cathodes for SIBs.
Manganese-based Prussian blue analogues (MnPBA) have attracted significant attention as cathode materials for sodium-ion batteries (SIBs) due to its high capacity, elevated operating voltage, simple synthesis process, and low cost. However, the harmful Jahn–Teller effect in MnPBA leads to manganese dissolution and anisotropic volume changes, resulting in structural instability and capacity degradation. Here, we report an in situ electrochemical method that substitutes the sodium storage sites (A-site) in MnPBA by embedding Mg2+, Ca2+, Sr2+ and Ba2+ during discharge. The substitution ions provide structural support to alleviate the Jahn–Teller distortion, further regulate the charge distribution around Mn2+, strengthen the Mn–N bonding, and thus effectively suppress manganese dissolution. As identified through theoretical screening calculations considering thermodynamic and kinetic parameters, the lowest formation energy of Ca2+ for A-site embedding, its ability to form the strongest Mn–N bonds, and its optimal pinning tendency collectively make it the optimal A‑site substitution ion for stabilizing MnPBA. The prepared cathode retains 78.5% capacity after 300 cycles at 1 C, significantly outperforming pure MnPBA (22.8%). This work offers key insights into A-site substitution approaches for designing high-performance SIBs cathode materials.
Given the cost-effectiveness, renewability, and environmental friendliness features, biomass-derived hard carbon has attracted significant attention in sodium-ion batteries (SIBs). However, the macroproperties of the resultant hard carbon highly depend on the resources and components of the biomass precursors. And the structure-property relationship remains complicated, which brings huge challenges for subsequent research. To clarify such intrinsic correlation, this review systematically elucidates the physicochemical propert ies, multiscale mechanisms, as well as isolation approaches of the cellulose, hemicellulose, and lignin first, with special focus on the differential evolution behavior and its synergistic transformation mechanism of these three main components during the pyrolysis-carbonization process. Then, the key regulation effects on microstructure and sodium storage performance have also been illuminate d based on the structural evolution of these component s. Subsequently, by comparing different modification methods, an innovative precursor pretreatment strategy for component matching and correlation with sodium storage characteristics has been proposed, which can control the path of degradation and reconstruction of components and thus optimize the electrochemical behaviors of the resulting hard carbons. Finally, multi-dimensional solutions are raised in order to target the industrialization bottlenecks. These solutions provide a theoretical foundation and technical roadmap for the development of high-performance, low-cost SIBs anode materials.
Silicon possesses a high theoretical capacity, making it a potential contender for lithium-ion battery (LIB) anodes. Nonetheless, its practical usage is challenged by low electrical conductivity and significant volume expansion during cycling. Here, we synthesized a novel silicon/carbon (Si/C) anode doped with ZnO via a template-derived method and high-temperature carbonization. The carbon structure, originated from metal-organic frameworks (MOFs) and ZnO doping, substantially enhanced the electrochemical properties of the composite material. exhibited an initial capacity of 2 100.3 mA h g-1 at a current density of 0.2 A g-1 and demonstrated excellent capacity retention over successive cycles. Moreover, the composite material displayed superior rate performance at higher current densities of 2 A g-1 and 3 A g-1. To address the low initial Coulombic efficiency (ICE) of silicon based materials, we adopted a direct contact prelithiation approach and optimized the lithiation process controlling the prelithiation time. After 30 min of prelithiation, the ICE reached 97.9 %, thereby reducing initial irreversible capacity loss (ICL) and realizing stable discharge-charge in subsequent cycles. This rational design provides valuable insights for achieving high-performance silicon anode.
ABSTRACT Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 (NFPP), with its high specific capacity and excellent structural stability, is a promising cathode material for sodium‐ion batteries. This study reveals the structural regulation mechanism of cobalt‐doped Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 cathode materials and demonstrates their optimization effects on the high‐voltage performance of sodium‐ion batteries. By combining multi‐scale characterization with electrochemical testing, we reveal that Co substitution for Fe can induce lattice expansion, stabilize the (210) crystal plane, and enhance Na + diffusion. Na 4 Fe 2.7 Co 0.3 (PO 4 ) 2 P 2 O 7 (NFCPP‐3) exhibits remarkable rate performance (82.3 mAh g −1 at 100C) and long‐term cycling stability (85.6% after 5000 cycles at 10C). DFT calculations show cobalt doping significantly enhances the material's adaptability under high voltage conditions by reducing the formation energy of the (210) crystal plane (E f : 0.158→0.151 eV) and Na + migration energy barriers (0.807 → 0.623 eV). Furthermore, full cell testing (NFCPP‐3//HC) confirms practical application potential, with a capacity retention of 82 mAh g −1 at 10C and 94.1% after 450 cycles at 1C. This study provides a new perspective for developing cathode materials for high‐voltage and high‐rate sodium‐ion batteries.
ABSTRACT Among available cathode materials of sodium ion batteries (SIBs), the sodium layered transition metal oxides (Na x TMO 2 ) stand out owing to their high specific capacity and suitable working voltage. However, they are commonly plagued by lattice collapse, irreversible phase transition, and poor air stability, which severely limit their cycle durability and rate capability. To address the persistent challenges of Na x TMO 2 , structural regulation strategies based on the pillar and pinning effects have emerged as effective approaches. The ions serving as pillars in the alkali metal layer can expand the interslab spacing and strengthen interlayer interactions, thus constructing efficient Na + migration pathways and establishing a robust lattice framework. Similarly, the pinning ions in the TM and/or alkali metal layers acting as nails help to stabilize phase configuration, especially in deeply sodiated and desodiated states. Both pillar and pinning effects are extensively employed to optimize the structural stability, phase evolution behavior, and electrochemical properties of Na x TMO 2 . This review systematically summarizes recent advances in Na x TMO 2 regulated by pillar and pinning effects, primarily focusing on their construction approaches and underlying enhancement mechanisms. Finally, we outline the ongoing challenges and future research directions for Na x TMO 2 modified by the pillar or pinning effects.
Sodium-based Prussian blue analogues (NaPBA) are promising cathodes for sodium-ion batteries owing to their high capacity and low cost. Nonetheless, rapid capacity fading during prolonged cycling remains a critical challenge, as the underlying degradation mechanisms are not fully understood. Here, we employ deuterium isotope labeling to unveil a dual-coupled degradation pathway in NaPBA cathodes, where crystalline water-induced lattice distortion is coupled with defect-triggered electrolyte decomposition. Density functional theory screening identifies In(OTf)3 as a multifunctional electrolyte additive, which suppresses both degradation processes via synergistic cation-anion effects. Molecular dynamics simulations and isotope-ratio mass spectrometry (IRMS) reveal that In3+ strongly coordinates with crystalline water, suppressing its repeated insertion/extraction and preventing framework collapse, while OTf-- anions passivate [Fe(CN)6]4- vacancies, reducing solvent adsorption and inhibiting electrolyte decomposition at defect sites. Consequently, the NaPBA||Na cells incorporating In(OTf)3 exhibit significantly improved electrochemical performance, demonstrating 80.63% capacity retention after 1000 cycles at 1C and nearly threefold higher discharge capacity at 20C compared to baseline cells, outperforming the most reported PBA-based batteries. This cation-anion modulation strategy provides a general design principle for electrolyte engineering in PBA-based energy-storage systems.
Phase transitions in sodium layered transition metal (TM) oxides often induce microstrain and TM ion migration, leading to structural degradation and poor cycling stability. However, a rational design approach for optimizing phase transitions is still lacking. Here we introduce phase transition potential (Φphase) as a rational descriptor to predict and control phase evolution in these cathodes. A lower Φphase enables smoother Na+ migration and slower slab sliding during Na extraction, thereby facilitating a continuous phase transformation rather than abrupt phase changes. Guided by this concept, we design a calcium-substituted layered oxide, Na0.96Ca0.02Ni0.33Fe0.33Mn0.33O2 (NCNFMO), which delivers a specific capacity of 140 mAh g-1 at 0.1 C and retains 84.2% of its initial capacity after 500 cycles at 1 C, compared to only 26.4% retention for NaNi0.33Fe0.33Mn0.33O2. Moreover, the NCNFMO||Al@C full cell maintains a high-capacity retention of 82.5% after 100 cycles, and 6.1 Ah full cell demonstrates an energy density of 192 Wh kg-1 entire cell. These findings offer fundamental insights into phase behavior-induced microstrain and a promising path toward high-energy, long-life sodium-ion batteries.
In situ characterization techniques are used to identify structural evolution, the configuration of metal active sites, key oxygen-containing intermediates, and gas products, thereby providing comprehensive mechanistic insights into OER pathways.
Nickel-rich nickel phosphide (Ni2P) has emerged as a promising sodium-ion battery anode owing to its high theoretical capacity and intrinsic electronic conductivity, yet its charge storage chemistry remains controversial and is often oversimplified as a conversion reaction. Herein, we design a freestanding Ni2P composite electrode composed of ultrasmall Ni2P nanocrystals embedded within a phosphorus-doped, graphene-like porous carbon matrix. Comprehensive in-situ and ex-situ analyses unequivocally demonstrate an interstitial solid-solution mechanism, wherein Na+ ions reversibly occupy lattice interstitials via (111)-oriented interplanar channels, inducing reversible lattice breathing without phase transformation. This bulk intercalation process is synergistically coupled with a substantial pseudocapacitive contribution, establishing a cooperative dual-mode storage mechanism. Benefiting from this solid-solution–capacitive chemistry, the electrode delivers a high reversible capacity (≈560 mAh g−1), outstanding rate capability (135 mAh g−1 at 10 A g−1), and exceptional long-term stability (263 mAh g−1 after 2000 cycles). When paired with a Na3V2(PO4)3@C cathode, the full cell achieves a high-energy density of 245 Wh kg−1. This work establishes solid-solution–capacitive coupling as a general paradigm for designing high-rate and durable sodium-ion battery anodes.
Li-rich Mn-based layered oxides (LRMOs) are essential cathode materials for higher energy densities in batteries. Nevertheless, the release of reactive oxygen species (ROS) at high voltages, accompanied by the migration of surface oxygen vacancies and transition metal ions, results in continuous electrolyte decomposition, irreversible phase transition, and nanovoids formation within bulk materials. These processes significantly shorten cycle life of batteries and limit practical applications. Herein, inspired by biological properties of taurine (TA) in scavenging ROS, we propose a straightforward cathode additive strategy by employing TA to effectively interact with ROS, thereby generating a reversible TA/peroxotaurine redox couple. This innovative mechanism enables efficient recycling of ROS, which in turn inhibits continuous electrolyte decomposition, O2 release, and nanovoid formation. Furthermore, the derived high-quality cathode electrolyte interphase layer, which is rich in inorganic components and thinner in structure, stabilizes the layered structure while ensuring efficient Li+ transport kinetics. Consequently, the modified LRMO demonstrates an exceptional initial Coulombic efficiency of 89% (vs. 81% for LRMO), and a splendid capacity retention of 92% at 1C after 400 cycles (vs. 68% for LRMO). Additionally, the pouch cell paired with graphite anodes exhibits superior capacity retention of 78% after 1000 ultra-long cycles at 1/3C.
Despite considerable advancements in the synthesis of two-dimensional (2D) mesoporous nanomaterials, achieving precise control over their components, morphology, lateral dimension, and thickness remains a formidable challenge. Here, we report a rational interface-confined anisotropic assembly strategy that enables the synthesis of square-shaped 2D mesoporous nanosheets with finely tunable features including compositions (metal ion-doped mesoporous polydopamine or silica), lateral dimensions (100-200 nm), thicknesses (14-25 nm), and in-plane mesopore sizes (8-20 nm). In this strategy, truncated rhombic dodecahedral ZIF-8 metal-organic framework (MOF) nanoparticles serve as seeds to direct the selective assembly of mesoporous micelles onto their six {100} facets. The geometric confinement of these square facets guides the interfacial organization of micelles into 2D sheet-like structure, faithfully inheriting the square geometry. Following etching of the ZIF-8 seeds, the resulting nanosheets preserve their well-defined square-shaped 2D morphology and mesoporous architecture. This versatile approach enables the fabrication of diverse 2D mesoporous tunable structural attributes and metal-ion dopants. As a proof of concept, mPDA-Zn2+/Fe2+ nanosquares, featuring a uniform 2D architecture, near-infrared (NIR) photothermal properties, and Fenton-like catalytic activity, demonstrate synergistic therapeutic effects. Compared to conventional spherical analogs (1.08 × 10-8 M/s), these nanosquares (2.11 × 10-8 M/s) achieve nearly doubled maximum reaction rates and achieved remarkable tumor inhibition of up to 90%. Overall, this study establishes a novel approach for the precise engineering of 2D mesoporous nanosquares with controllable parameters, unlocking new opportunities for applications in biomedicine and beyond.
Although Na4MnV(PO4)3 (NMVP) is regarded as a promising cathode material for sodium-ion batteries, low capacity and structural degradation upon cycling limit its practical application. Doping is an efficient way to enable Na+ migration and stabilize MnO6/VO6 octahedra during cycling. However, the potential roles of different-site dopants, especially how multi-site doping in NMVP works synergistically, remain elusive. Here, taking Na-site K dopant and Mn/V-sites Al dopant as a typical example, the distinct roles of K and Al dopants have been identified in enhancing Na+ diffusion and simultaneously ensuring structural stability of NMVP. Specifically, Na3.7K0.2Mn0.9Al0.1V0.9Al0.1(PO4)3 (NKMAVAP) has been developed in which such multi-site doping not only alters local chemical environments of Mn/V/Na sites for enhancing electronic/ionic conductivity, but also inhibits large structural strain of MnO6/VO6 octahedra upon cycling. Importantly, Al dopant at Mn sites plays a critical role in boosting Na+ migration and enhancing structural stability of NMVP, achieving an order of magnitude increase in chemical diffusion coefficient of Na+ in the second-step Na+ extraction/insertion processes. Based on theoretical calculations and experimental findings, NKMAVAP exhibits the optimized electrochemical performance with a rate capability of 72.2 mAh g−1 at 20C and a capacity retention of 92.1% after 2000 cycles at 15C.
Per- and polyfluoroalkyl substances (PFAS) are among the most persistent and challenging environmental pollutants. Compared with conventional oxidative or homogeneous reduction processes, electrochemical and photoelectrochemical reduction (ER and PER) offer reagent-free routes for PFAS destruction but remain limited by poor PFAS removal and sluggish defluorination under cathodic conditions. Here, we report a Pd-decorated TiO2 cathode that enables highly efficient photoelectrochemical degradation of perfluorooctane sulfonic acid (PFOS) under ambient conditions. Operando spectroscopy and density functional theory (DFT) calculations uncover a previously unrecognized mechanism in which cathodic potentials promote PFAS adsorption on TiO2, while UV254-excited Pd sites generate hot electrons that directly drive C-F bond cleavage or form hydrated electrons for indirect reduction. This dual-electron pathway leads to rapid and deep defluorination, outperforming previously reported ER and PER systems even in complex matrices such as reverse osmosis concentrate (ROC) and aqueous film-forming foam (AFFF)-impacted water. The study further demonstrates scalable single-chamber reactor designs and mesh-type cathodes, advancing the practical implementation of photoelectrochemical PFAS destruction technologies.
Developing cost-effective and durable electrocatalysts for both hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) is essential for energy-efficient hydrogen production via urea-assisted water electrolysis. Herein, a Ce and V co-doped WOx/Ni17W3 heterostructure (CeV-WOx/Ni17W3) was constructed through element doping and interfacial engineering to optimize its electronic structure and catalytic activity. The optimized catalyst delivers low overpotentials of 12, 34, 42, and 19 mV at 10 mA cm-2 in alkaline, neutral, acidic, and alkaline seawater electrolytes, respectively. For UOR, only 1.35 V is required to achieve 10 mA cm-2. When applied to urea-assisted overall water splitting, a cell voltage of 1.55 V is sufficient to reach 100 mA cm-2, outperforming commercial Pt/C and RuO2. Density functional theory calculations indicate that Ce and V co-doping induces electron redistribution in WO2.72, modulating the d-band center and optimizing the Gibbs free energy of H* adsorption, thereby accelerating HER kinetics. This work provides an effective strategy for designing multifunctional electrocatalysts for sustainable hydrogen production and urea-rich wastewater treatment.
All-solid-state sodium batteries (ASSSBs) stand out as a transformative energy storage technology, combining sodium's natural abundance with enhanced safety and competitive energy density. Solid electrolytes are pivotal to this innovation, with halide electrolytes emerging as prominent candidates due to their unique strengths-superior deformability for intimate electrode contact, strong cathode compatibility, and promising Na-ion conductivity. Despite recent progress, significant challenges persist in scalable synthesis, performance optimization, and mechanistic understanding of ion transport and interfacial interactions. This review comprehensively covers sodium-based halide electrolytes, including their structural chemistry, ion transport, synthesis, modification, electrochemical stability, interfacial behavior, and computational insights. We further integrate a systematic framework to elucidate intricate synthesis-structure-property relationships, enabling a holistic understanding for rational material design. Crucially, this work distinguishes itself by distilling concrete design principles for Na-halide conductors, providing quantitative insights into humidity stability, and establishing in-depth correlations between interphases/degradation modes and full-cell metrics. Moreover, a practical assessment of key performance metrics (energy density, power density, cycle life) and design guidance is presented. Finally, we pinpoint critical barriers (moisture sensitivity, anode incompatibility, and conductivity limitations) and outline a roadmap emphasizing compositional design, interface engineering, manufacturing scalability, machine learning, operando characterization, and standardized metrics to accelerate commercialization.