Core-Shell Structure of Polyoxovanadate Coated with Polyaniline for High-Performance Aqueous Zinc-Ion Battery Cathode Materials.

Aqueous zinc-ion batteries (AZIBs) are candidates for energy storage systems due to their high safety, low cost, and high theoretical capacity, whereas their practical application is severely impeded by the slow reaction kinetics and structural instability of the cathode materials. Herein, the core-shell structure of polyoxovanadates {Mn(HO)VO(SO)} (MnVO) coated with polyaniline (PANI) is developed as the cathode material for AZIBs. The tri-dimensional robust MnVO offers abundant active sites and high porosity, and the highly conductive PANI significantly accelerates the electron/ion transfer transport and prevents the dissolution of polyoxovanadates, which effectively enhance reaction kinetics and provide sufficient space for improving Zn storage performance.

Synergistic cation-anion regulation of active water within inner Helmholtz plane enables ultra-stable aqueous Zn ion batteries.

The issues related to corrosion, dendrite growth, and hydrogen evolution reaction (HER) of the Zn anode in aqueous environments have significantly obstructed the practical implementation of aqueous zinc ion batteries (AZIBs). Herein, the strategy of synergistically regulating the content of active water molecules located within the inner Helmholtz plane (IHP) by anions and cations is used to address the above-mentioned water-related issues of zinc metal anodes via using the 1-Ethyl-3-methylimidazolium tetrafluoroborate ionic liquid (IL) as an highly effective electrolyte additive. Theoretical computations and empirical outcomes show that the IL indirectly regulates IHP by tailoring solvation structure of Zn via anions and adsorbing cations on the surface of the zinc anode, directly and effectively reducing the content of chemically active HO molecules in IHP and thus significantly inhibiting the adverse reactions related to active HO molecules.

Multiple redox Centers and defect engineering in Fe/Mo dual-doped NaV(PO) cathodes for high-performance sodium-ion batteries.

Sodium superionic conductor (NASICON)-type phosphates cathodes have attracted considerable attention due to their high operational voltage and robust three-dimensional (3D) framework; however, the poor intrinsic electronic conductivity and low energy density hinder their broader application. Herein, a novel NASICON-type NaVFeMo(PO) cathode was designed through Fe/Mo dual-doping at the V sites of NaV(PO) and synthesized via a conventional high-temperature solid-state method. The introduction of Fe activates the V/V redox couple at a high voltage plateau (∼ 4.

Morphology regulation and vacancy engineering for vanadium oxide cathodes via tungsten doping towards advanced zinc-ion batteries.

Recently, vanadium oxide of VO has emerged as a promising cathode material for aqueous zinc-ion batteries (AZIBs) due to its high theoretical specific capacity, abundant reserves, and the multiple adjustable oxidation states of vanadium. However, its poor electronic conductivity and severe structural collapse during cycling limit its practical application. Herein, a W-doped VO nanobelt cathode was synthesized via a one-step solvothermal method.

Redox-mediated oxygen evolution reaction: Engineering oxygen vacancies and heterojunctions in CeFeCo-UiO-66/layered double hydroxide via a two-step corrosion strategy.

Modifying metal-organic frameworks (MOFs)-based electrocatalysts remains crucial for enhancing oxygen evolution reaction (OER) performance. Although oxygen vacancies (V) are recognized as important for OER, their concentration control and relationship with catalytic activity remain unclear. In this study, we employ the redox potential difference between Co (0.

High-entropy doping in NASICON cathodes: Activating the V/V redox couple and inducing a reversible single solid-solution phase reaction for advanced sodium ion batteries.

NaV(PO) (NVP) with typical NASICON structure is highly regarded as one of the most appealing cathodes for sodium-ion batteries (SIBs) for their excellent structural stability; however, the poor electronic conductivity and irreversible phase transition at high voltage (∼4 V) for the material result in poor rate capabilities and significant capacity degradation during electrochemical reactions. Herein, the high-entropy doping strategy of introducing six types of metal ions into the V-sites in NaV(PO) is used to design a high-performance cathode of NaV(Mn, Ca, Mg, Al, Zr)Nb(PO) (HE-NVP) for SIBs. After the high-entropy doping, a reversible V/V redox pair is activated at high voltage of ∼4 V, which significantly contributes to the enhancement of energy density and operating voltage.

Construction of NiP/WS/CoWO@C multi-heterojunction electrocatalysis derived from heterometallic clusters for superior overall water splitting.

The reasonable design of an economical and robust bifunctional electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is both essential but challenging. Herein, we synthesized a multi-interfacial NiP/WS/CoWO@C hybrid electrocatalyst devived from the heterometallic clusters [Co(TC4A)(WO)Cl][HPWO], in which NiP was incorporated into WS/CoWO@C nanosheets via interfacial interactions by in situ phosphorization processes. Theoretical calculations revealed that moderate electron transfer from CoWO and NiP to WS induced by the multi-heterojunction significantly regulate the binding energies of the reactive intermediates, thus enhacing its intrinsic activity.

Anion Doping and Dual-Carbon Confinement Strategies to Synergistically Boost the Sodium Storage Performance of Cobalt-Based Sulfides.

Cobalt-based sulfides (CSs) are generally regarded as potentially valuable anode materials for sodium-ion batteries (SIBs) due to their excellent theoretical capacity and natural abundance. Nevertheless, their slow reaction kinetics and poor structural stability restrict the practical application of the materials. In this study, the dual-carbon-confined Se-CoS@NC@C hollow nanocubes with anion doping are synthesized using ZIF-67 as the substrate by resorcin-formaldehyde (RF) encapsulation and subsequent carbonization and sulfurization/selenization.

Trace alcohol ether electrolytes with dual-site hydrogen bonds and modulated solvation structures for ultralong-life zinc-ion batteries.

Aqueous zinc-ion batteries (AZIBs) are highly regarded for their affordability, stability, safety, and eco-friendliness. Nevertheless, their practical application is hindered by severe side reactions and the formation of zinc (Zn) dendrites on the Zn metal anode surface. In this study, we employ tetrahydrofuran alcohol (THFA), an efficient and cost-effective alcohol ether electrolyte, to mitigate these issues and achieve ultralong-life AZIBs.

Modulating solvated structure of Zn and inducing surface crystallography by a simple organic molecule with abundant polar functional groups to synergistically stabilize zinc metal anodes for long-life aqueous zinc-ion batteries.

Aqueous zinc-ion batteries (AZIBs) have attracted significant attention owing to their inherent security, low cost, abundant zinc (Zn) resources and high energy density. Nevertheless, the growth of zinc dendrites and side reactions on the surface of Zn anodes during repeatedly plating/stripping shorten the cycle life of AZIBs. Herein, a simple organic molecule with abundant polar functional groups, 2,2,2-trifluoroether formate (TF), has been proposed as a high-efficient additive in the ZnSO electrolyte to suppress the growth of Zn dendrites and side reaction during cycling.

Heterogeneous engineering and carbon confinement strategy to synergistically boost the sodium storage performance of transition metal selenides.

Transition metal selenides (TMSs) stand out as a promising anode material for sodium-ion batteries (SIBs) owing to their natural resources and exceptional sodium storage capacity. Despite these advantages, their practical application faces challenges, such as poor electronic conductivity, sluggish reaction kinetics and severe agglomeration during electrochemical reactions, hindering their effective utilization. Herein, the dual-carbon-confined CoSe/FeSe@NC@C nanocubes with heterogeneous structure are synthesized using ZIF-67 as the template by ion exchange, resorcin-formaldehyde (RF) coating, and subsequent in situ carbonization and selenidation.

Rod-like Ni-CoS@NC@C: Structural design, heteroatom doping and carbon confinement engineering to synergistically boost sodium storage performance.

Currently, conversion-type transition metal sulfides have been extensively favored as the anodes for sodium-ion batteries due to their excellent redox reversibility and high theoretical capacity; however, they generally suffer from large volume expansion and structural instability during repeatedly Na de/intercalation. Herein, spatially dual-confined Ni-doped CoS@NC@C microrods (Ni-CoS@NC@C) are developed via structural design, heteroatom doping and carbon confinement to boost sodium storage performance of the material. The morphology of one-dimensional-structured microrods effectively enlarges the electrode/electrolyte contact area, while the confinement of dual-carbon layers greatly alleviates the volume change-induced stress, pulverization, agglomeration of the material during charging and discharging.

Hollow VO microspheres anchored on graphene as advanced cathodes for aqueous zinc-ion batteries.

Vanadium dioxide-based materials have been proved to be promising cathodes for aqueous zinc ion batteries (AZIBs) due to their cost-effectiveness and high theoretical specific capacity; nevertheless, the low electronic conductivity and poor cycle stability restrict their application. Herein, hollow VO microspheres anchored on graphene oxide (H-VO@GO) are synthesized via a facile simple hydrothermal reaction as high-performance cathodes for AZIBs. The hollow micromorphology of the material provides a large specific surface area and effectively alleviates the volume changes during cycling, while the anchoring of VO on graphene oxide greatly improves the electronic conductivity and inhibits the agglomeration and pulverization of the material.

Heterometallic Electrocatalysts Derived from High-Nuclearity Metal Clusters for Efficient Overall Water Splitting.

The development of cost-effective electrocatalysts with an optimal surface affinity for intermediates is essential for sustainable hydrogen fuel production, but this remains insufficient. Here we synthesize NiP/MoS-CoMoS@C heterometallic electrocatalysts based on the high-nuclearity cluster {Co(TC4A)(MoO)Cl}, in which NiP nanoparticles were anchored to the surface of the MoS-CoMoS@C nanosheets via strong interfacial interactions. Theoretical calculations revealed that the introduction of NiP phases induces significant disturbances in the surface electronic configuration of NiP/MoS-CoMoS@C, resulting in more relaxed d-d orbital electron transfers between the metal atoms.

Optimizing Interplanar Spacing, Oxygen Vacancies and Micromorphology via Lithium-Ion Pre-Insertion into Ammonium Vanadate Nanosheets for Advanced Cathodes in Aqueous Zinc-Ion Batteries.

Ammonium vanadates, featuring an N─H···O hydrogen bond network structure between NH and V─O layers, have become popular cathode materials for aqueous zinc-ion batteries (AZIBs). Their appeal lies in their multi-electron transfer, high specific capacity, and facile synthesis. However, a major drawback arises as Zn ions tend to form bonds with electronegative oxygen atoms between V─O layers during cycling, leading to irreversible structural collapse.

High-efficiency activated phosphorus-doped NiS/CoS/ZnS nanowire/nanosheet arrays for energy storage of supercapacitors.

Transition metal sulfides (TMS) have been considered as a promising group of electrode materials for supercapacitors as a result of their strong redox activity, but high volumetric strain of the materials during electrochemical reactions causes rapid structural collapse and severe capacity loss. Herein, we have synthesized phosphorus-doped (P-doped) NiS/CoS/ZnS battery-type nanowire/nanosheet arrays as an advanced cathode for supercapacitor through a two-step process of hydrothermal and annealing treatments. The material has a one-dimensional nanowire/two-dimensional nanosheet-like coexisting microscopic morphology, which facilitates the exposure of abundant active centers and promotes the transport and migration of ions in the electrolyte, while the doping of P significantly enhances the conductivity of the electrode material.

Boosting the sodium storage performance of iron selenides by a synergetic effect of vacancy engineering and spatial confinement.

Recently, iron selenides have been considered as one of the most promising candidates for the anodes of sodium-ion batteries (SIBs) due to their cost-effectiveness and high theoretical capacity; however, their practical application is limited by poor conductivity, large volume variation and slow reaction kinetics during electrochemical reactions. In this work, spatially dual-carbon-confined V-FeSeS/FeSeS nanohybrids with abundant Se vacancies (V-FeSeS/FeSeS@NSC@rGO) are constructed via anion doping and carbon confinement engineering. The three-dimensional crosslinked carbon network composed of the nitrogen-doped carbon support derived from polyacrylic acid (PAA) and reduced graphene enhances the electronic conductivity, provides abundant channels for ion/electron transfer, ensures the structure integrity, and alleviates the agglomeration, pulverization and volume change of active material during the chemical reactions.

A high-energy-density NASICON-type NaVGa(PO) cathode with reversible V/V redox couple for sodium ion batteries.

The stable three-dimensional framework and high operating voltage of sodium superionic conductor (NASICON)-type NaV(PO) has the potential to work with long cycle life and high-rate performance; however, it suffers from the poor intrinsic electronic conductivity and low energy density. Herein, Ga is introduced into NaV(PO) to activate the V/V redox couple at a high potential of 4.0 V for enhancing energy density of the materials (NaVGa(PO)).

Efficient Suppression of Dendrites and Side Reactions by Strong Electrostatic Shielding Effect via the Additive of Rb SO for Anodes in Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (AZIBs) have attracted considerable attention due to their low cost and environmental friendliness. However, the rampant dendrite growth and severe side reactions during plating/stripping on the surface of zinc (Zn) anode hinder the practicability of AZIBs. Herein, an effective and non-toxic cationic electrolyte additive of Rb SO is proposed to address the issues.

High-Energy-Density Cathode Achieved via the Activation of a Three-Electron Reaction in Sodium Manganese Vanadium Phosphate for Sodium-Ion Batteries.

Sodium superionic conductor (NASICON)-type Na V (PO ) has attracted considerable interest owing to its stable three-dimensional framework and high operating voltage; however, it suffers from a low-energy density due to the poor intrinsic electronic conductivity and limited redox couples. Herein, the partial substitution of Mn for V in Na V (PO ) is proposed to activate V /V redox couple for boosting energy density of the cathodes (Na V Mn (PO ) ). With the introduction of Mn into Na V (PO ) , the band gap is significantly reduced by 1.

Molybdenum-optimized electronic structure and micromorphology to boost zinc ions storage properties of vanadium dioxide nanoflowers as an advanced cathode for aqueous zinc-ion batteries.

Recently, vanadium dioxide (VO) has been recognized as one of the most prospective cathodes for aqueous zinc ion batteries (AZIBs) for its high reversible specific capacity; nevertheless, its Zn diffusion kinetics and cycling stability have not yet met expectations. Herein, Mo ions are introduced into VO to optimize the intrinsic electronic structure and micromorphology of VO, achieving significantly enhanced zinc-ion storage. It is found that the substitution of Mo for V narrows the band gap of VO and thus enhances the conductivity of the material, while VO nanorods are transformed into VO nanoflowers which are self-assembled from ultra-thin nanosheets after the introduction of Mo, exposing much more active sites to enhance the migration kinetics of Zn.

Constructing MIL-53(Fe)@ZIF-67(Co) binary metal-organic framework hierarchical heterostructure electrodes for efficient oxygen evolution.

Improving the efficiency of the anodic oxygen evolution reaction (OER) is important to solve the global energy crisis and greenhouse gas emission problems. In this paper, a preparation method for a MIL-53(Fe)@ZIF-67(Co) composite electrode is proposed. The hierarchical structure formed by the combination of MIL-53(Fe) and ZIF-67(Co) provides a rich channel for the transport of electrons and mass in the OER process.

Homologous Heterostructured NiS/NiS @C Hollow Ultrathin Microspheres with Interfacial Electron Redistribution for High-Performance Sodium Storage.

Nickel sulfides with high theoretical capacity are considered as promising anode materials for sodium-ion batteries (SIBs); however, their intrinsic poor electric conductivity, large volume change during charging/discharging, and easy sulfur dissolution result in inferior electrochemical performance for sodium storage. Herein, a hierarchical hollow microsphere is assembled from heterostructured NiS/NiS nanoparticles confined by in situ carbon layer (H-NiS/NiS @C) via regulating the sulfidation temperature of the precursor Ni-MOFs. The morphology of ultrathin hollow spherical shells and confinement of in situ carbon layer to active materials provide rich channels for ion/electron transfer and alleviate the effects of volume change and agglomeration of the material.

Multilevel spatial confinement of transition metal selenides porous microcubes for efficient and stable potassium storage.

Recently, potassium-ion batteries (PIBs) have been considered as one of the most promising energy storage systems; however, the slow kinetics and large volume variation induced by the large radius of potassium ions (K) during chemical reactions lead to inferior structural stability and weak electrochemical activity for most potassium storage anodes. Herein, a multilevel space confinement strategy is proposed for developing zinc-cobalt bimetallic selenide (ZnSe/CoSe@NC@C@rGO) as high-efficient anodes for PIBs by in-situ carbonizing and subsequently selenizing the resorcinol-formaldehyde (RF)-coated zeolitic imidazolate framework-8/zeolitic imidazolate framework-67 (ZIF-8/ZIF-67) encapsulated into 2D graphene. The highly porous carbon microcubes derived from ZIF-8/ZIF-67 and carbon shell arising from RF provide rich channels for ion/electron transfer, present a rigid skeleton to ensure the structural stability, offer space for accommodating the volume change, and minimize the agglomeration of active material during the insertion/extraction of large-radius K.