Hierarchical Microtubes Constructed by MoS2 Nanosheets with Enhanced Sodium Storage Performance

High-throughput arousing interconnected interfaces for excellent sodium storage chemistry

Heterostructures endow electrochemical hybrids with promising energy storage properties owing to synergistic effects and interfacial interaction. However, developing a facile but effective approach to maximize interface effects is crucial but challenging. Herein, a bimetallic sulfide/carbon heterostructure is realized in a confined carbon network via a high-throughput template-assisted strategy to induce highly active and stable electrode architecture. The designed heterostructures not only yield abundant interconnected Co9S8/MoS2/N-doped carbon (Co9S8/MoS2/NC) heterojunctions with continuous channels for ion/electron transfer but maintain excellent conversion reversibility. Serving as anode for sodium storage, the Co9S8/MoS2/NC framework displayed excellent sodium storage properties (reversible capacity of 480 mAh/g after 100 cycles at 0.2 A/g and 286.2 mAh/g after 500 cycles at 2 A/g). Given this, this study can guide future design protocols for interface engineering by forming dynamic channels of conversion reaction kinetics for potential applications in high-performance electrodes.

Superior sodiophilicity and molecule crowding of crown ether boost the electrochemical performance of all-climate sodium-ion batteries

Sodium-ion batteries (SIBs) as one of the promising alternatives to lithium-ion batteries have achieved remarkable progress in the past. However, the all-climate performance is still very challenging for SIBs. Herein, 15-Crown-5 (15-C-5) is screened as an electrolyte additive from a number of ether molecules theoretically. The good sodiophilicity, high molecule rigidity, and bulky size enable it to reshape the solvation sheath and promote the anion engagement in the solvated structures by molecule crowding. This change also enhances Na-ion transfer, inhibits side reactions, and leads to a thin and robust solid-electrolyte interphase. Furthermore, the electrochemical stability and operating temperature windows of the electrolyte are extended. These profits improve the electrochemical performance of SIBs in all climates, much better than the case without 15-C-5. This improvement is also adopted to μ-Sn, μ-Bi, hard carbon, and MoS2. This work opens a door to prioritize the potential molecules in theory for advanced electrolytes.

MoS2, WS2, and MoWS2 Flakes as Reversible Host Materials for Sodium-Ion and Potassium-Ion Batteries

Transition-metal dichalcogenides (TMDs) and their alloys are vital for the development of sustainable and economical energy storage alternatives due to their large interlayer spacing and hosting ability for alkali-metal ions. Although the Li-ion chemically correlates with the Na-ion and K-ion, research on batteries with TMD anodes for K+ is still in its infancy. This research explores TMDs such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2) and TMD alloys such as molybdenum tungsten disulfide (MoWS2) for both sodium-ion batteries (NIBs) and potassium-ion batteries (KIBs). The cyclic stability test analysis indicates that in the initial cycle, the MoS2 NIB demonstrates exceptional performance, with a peak charge capacity of 1056 mAh g-1, while retaining high Coulombic efficiency. However, the WS2 KIB underperforms, with the least charge capacity of 130 mAh g-1 in the first cycle and exceptionally low retention at a current density of 100 mA g-1. The MoWS2 TMD alloy exhibits a moderate charge capacity and cyclic efficiency for both NIBs and KIBs. This comparison study shows that decreasing sizes of alkali-metal ions and constituent elements in TMDs or TMD alloys leads to decreased resistance and slower degradation processes as indicated by cyclic voltammetry and electrochemical impedance spectroscopy after 10 cycles. Furthermore, the study of probable electrochemical intercalation and removal processes of Na-ions and K-ions demonstrates that large geometrically shaped TMD flakes are more responsive to intercalation for Na-ions than K-ions. These performance comparisons of different TMD materials for NIBs and KIBs may promote the future development of these batteries.

Synthesis and Electrocatalytic Applications of Layer-Structured Metal Chalcogenides Composites

Featured with the attractive properties such as large surface area, unique atomic layer thickness, excellent electronic conductivity, and superior catalytic activity, layered metal chalcogenides (LMCs) have received considerable research attention in electrocatalytic applications. In this review, the approaches developed to synthesize LMCs-based electrocatalysts are summarized. Recent progress in LMCs-based composites for electrochemical energy conversion applications including oxygen reduction reaction, carbon dioxide reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, overall water splitting, and nitrogen reduction reaction is reviewed, and the potential opportunities and practical obstacles for the development of LMCs-based composites as high-performing active substances for electrocatalytic applications are also discussed. This review may provide an inspiring guidance for developing high-performance LMCs for electrochemical energy conversion applications.

Interface engineering of metal sulfides-based composites enables high-performance anode materials for sodium-ion batteries

Metal sulfides (MSs) have attracted much attention as anode materials for sodium-ion batteries (SIBs) due to their high sodium storage capacity. However, the unsatisfactory electrochemical performance induced by the huge volume change and sluggish kinetics hampered the practical application of SIBs. Herein, guided by the heterostructure interface engineering, novel multicomponent metal sulfide-based anodes, including SnS, FeS, and Fe3N embedded in N-doped carbon nanosheets (SnS/FeS/Fe3N/NC NSs), have been synthesized for high-performance SIBs. The as-prepared SnS/FeS/Fe3N/NC NSs with abundant heterointerfaces and high conductivity of N-doped carbon nanosheet matrix can shorten the Na+ diffusion path and promote reaction kinetics during the sodiation/desodiation process. Moreover, the presence of Fe3N can promote the reversible conversion of SnS and FeS during the cycling process. As a consequence, when evaluated as anode materials for SIBs, the SnS/FeS/Fe3N/NC NSs can maintain a high sodium storage capacity of 473.6 mAh g-1 after 600 cycles at 2.0 A g-1 and can still provide a high reversible capacity of 537.4 mAh g-1 even at 5.0 A g-1 This discovery offers a novel strategy for constructing metal sulfide-based anode materials for high-performance SIBs.

Buffer solution induced highly crystalline sodium-rich Prussian blue for sodium storage

In this work, we have developed an efficient method to synthesize Prussian blue by self-decomposition of sodium ferrocyanide in acetic acid-sodium acetate buffer solution. This buffer solution-based proton pool provides a relatively low and stable concentration of protons for the slow decomposition of sodium ferrocyanide to get highly crystalline and sodium rich Prussian blue, which can be used as the cathode for high-performance sodium-ion batteries.

Hydrangea-like MoS2/carbon dots anode for high-performance sodium storage

Owing to their quantum size, edge effects, and abundant surface functional groups, carbon dots (CDs) have attracted significant attention. In this study, chitin-derived carbon dots (CT-CDs) were prepared and used to synthesize MoS2/CT-CDs. The abundant functional groups on the surface of the CT-CDs facilitated the orderly arrangement of MoS2 nanosheets, resulting in a hydrangea-like structure. When employed as the anode in a sodium-ion battery, MoS2/CT-CDs exhibited an excellent initial charging capacity of 492.6 mAh·g-1 at 0.1 A·g-1 with an initial Coulomb efficiency of 74.4%. Even after 100 cycles, the reversible capacity remained at 338.9 mAh·g-1. Furthermore, the reversible capacity of MoS2/CT-CDs remained at 219.9 mAh·g-1 after 260 cycles when subjected to 1 A·g-1. The hydrangea-like structure of MoS2/CT-CDs, with expanded layer spacing, enhances ion/electron transport while providing additional active sites for sodium-ion storage, resulting in exceptional cycling and rate performances.

Oxygen Defect Engineering toward Zero-Strain V2O2.8@Porous Reticular Carbon for Ultrastable Potassium Storage

Potassium-ion batteries (KIBs) are promising candidates for large-scale energy storage devices due to their high energy density and low cost. However, the large potassium-ion radius leads to its sluggish diffusion kinetics during intercalation into the lattice of the electrode material, resulting in electrode pulverization and poor cycle stability. Herein, vanadium trioxide anodes with different oxygen vacancy concentrations (V2O2.9, V2O2.8, and V2O2.7 determined by the neutron diffraction) are developed for KIBs. The V2O2.8 anode is optimal and exhibits excellent potassium storage performance due to the realization of expanded interlayer spacing and efficient ion/electron transport. In situ X-ray diffraction indicates that V2O2.8 is a zero-strain anode with a volumetric strain of 0.28% during the charge/discharge process. Density functional theory calculations show that the impacts of oxygen defects are embodied in reducing the band gap, increasing electron transfer ability, and lowering the diffusion energy barriers for potassium ions. As a result, the electrode of nanosized V2O2.8 embedded in porous reticular carbon (V2O2.8@PRC) delivers high reversible capacity (362 mAh g-1 at 0.05 A g-1), ultralong cycling stability (98.8% capacity retention after 3000 cycles at 2 A g-1), and superior pouch-type full-cell performance (221 mAh g-1 at 0.05 A g-1). This work presents an oxygen defect engineering strategy for ultrastable KIBs.

Metal-Organic Assembly Strategy for the Synthesis of Layered Metal Chalcogenide Anodes for Na+ /K+ -Ion Batteries

Layered transition metal chalcogenides (MX, M=Mo, W, Sn, V; X=S, Se, Te) have large ion transport channels and high specific capacity, making them promising for large-sized Na⁺ /K⁺ energy-storage technologies. Nevertheless, slow reaction kinetics and huge volume expansion will induce an undesirable electrochemical performance. Numerous efforts have been devoted to designing MX anodes and enhancing their electrochemical performance. Based on the metal-organic assembly strategy, nanostructural engineering, combination with carbon materials, and component regulation can be easily realized, which effectively boost the performance of MX anodes. In this Review, we present a comprehensive overview on the synthesis of MX nanostructure using the metal-organic assembly strategy, which can realize the design of MX nanostructures, based on self-sacrificial templates, host@guest tailored templates, post-modified layer and derivative templates. The preparation routes and structure evolution are mainly discussed. Then, Mo-, W-, Sn-, V-based chalcogenides used for Na⁺ /K⁺ energy storage are reviewed, and the relationship between the structure and the electrochemical performance, as well as the energy storage mechanism are emphasized. In addition, existing challenges and future perspectives are also presented.

Surface engineering of core-shell MoS2@N-doped carbon spheres as stable and ultra-long lifetime anode for sodium-ion batteries

MoS₂ is regarded as a hopeful anode candidate for sodium-ion batteries (SIBs) due to their various merits such as high specific capacity, abundant raw material reserves and low cost. However, their practical application is impeded by unsatisfied cycling ability due to the intense mechanical stress and unstable solid electrolyte interphase (SEI) during Na⁺ insertion/extraction process. Herein, spherical MoS₂@polydopamine derived highly conductive N-doped carbon (NC) shell composites (MoS₂@NC) are designed and synthesized to promote the cycling stability. The internal MoS₂ core is optimized and restructured from the original micron-sized block to the ultra-fine nanosheets during initial 100-200 cycles, which not only improves the utilization of electrode materials but also shortens the ion transport distance. The outer flexible NC shell effectively maintains the original spherical structure of the overall electrode material and prevents the occurrence of large-scale agglomeration, which is conducive to form a stable SEI layer. Therefore, the core-shell MoS₂@NC electrode presents a remarkable cyclic stability and a capable rate performance. Under a high rate of 20 A g^-1, the high capacity of 428 mAh g^-1 can be acquired after over ultra-long 10,000 cycles without obvious capacity loss. Moreover, the MoS₂@NC‖Na₃V₂(PO₄)₃ full-cell assembled by employing commercial Na₃V₂(PO₄)₃ cathode can achieve a high capacity retention of 91.4% after 250 cycles at 0.4 A g^-1. This work reveals the promising prospect of MoS₂-based materials as anode of SIBs, and also has some inspirations on the structural design for conversion-type electrode materials.

Reactive Template-Engaged Synthesis of NiSx/MoS2 Nanosheets Decorated on Hollow and Porous Carbon Microtubes with Optimal Electronic Modulation toward High-Performance Enzyme-like Performance

As a promising cost-effective nanozyme, MoS₂ nanosheets (NSs) have been considered as a good candidate for the enzyme-like catalysis. However, their catalytic activity is still restricted by the insufficient active sites and poor conductivity, and thus, the comprehensive performances are still unsatisfactory. To address these issues, herein, we design and fabricate an intelligent tubular nanostructure of hierarchical hollow nanotubes, which are assembled by NiS_x/MoS₂ NSs encapsulated into N-doped carbon microtubes (NiS_x/MoS₂@NCMTs). The N-doped carbon microtubes (NCMTs) serve as a conductive skeleton, integrating with NiS_x/MoS₂ NSs and ensuring their well-distribution, thereby maximally exposing more active sites. Additionally, the tube-like structure is favorable for increasing the mass transfusion to ensure their excellent catalytic performance. Profiting from their component and structural advantages, the obtained NiS_x/MoS₂@NCMTs exhibit a surprisingly enhanced enzyme-like activity. Based on these, a facile colorimetric sensing platform to detect H₂O₂ and GSH has been developed. This proposed approach can be expected to synthesize a series of tubular heterostructured MoS₂-based composites, which will be widely applied in catalysis, energy storage, disease diagnosis, etc.

Local Electric Field Induced by Atomic-Level Donor-Acceptor Couple of O Vacancies and Mn Atoms Enables Efficient Hybrid Capacitive Deionization

Transition metal oxides suffer from slow salt removal rate (SRR) due to inferior ions diffusion ability in hybrid capacitive deionization (HCDI). Local electric field (LEF) can efficiently improve the ions diffusion kinetics in thin electrodes for electrochemical energy storage. Nevertheless, it is still a challenge to facilitate the ions diffusion in bulk electrodes with high loading mass for HCDI. Herein, this work delicately constructs a LEF via engineering atomic-level donor (O vacancies)-acceptor (Mn atoms) couples, which significantly facilitates the ions diffusion and then enables a high-performance HCDI. The LEF boosts an extended accelerated ions diffusion channel at the particle surface and interparticle space, resulting in both remarkably enhanced SRR and salt removal capacity. Convincingly, the theoretical calculations demonstrate that electron-enriched Mn atoms center coupled with an electron-depleted O vacancies center is formed due to the electron back-donation from O vacancies to adjacent Mn centers. The resulted LEF efficiently reduce the ions diffusion energy barrier. This work sheds light on the effect of atomic-level LEF on improving ions diffusion kinetics at high loading mass application and paves the way for the design of transition metal oxides toward high-performance HCDI applications.

Hexaindium Heptasulfide/Nitrogen and Sulfur Co-Doped Carbon Hollow Microspindles with Ultrahigh-Rate Sodium Storage through Stable Conversion and Alloying Reactions

Group IIIA-VA metal sulfides (GMSs) have attracted increasing attention because of their unique Na-storage mechanisms through combined conversion and alloying reactions, thus delivering large theoretical capacities and low working potentials. However, Na⁺ diffusion within GMSs anodes leads to severe volume change, generally representing a fundamental limitation to rate capability and cycling stability. Here, monodispersed In₆ S₇ /nitrogen and sulfur co-doped carbon hollow microspindles (In₆ S₇ /NSC HMS) are produced by morphology-preserved thermal sulfurization of spindle-like and porous indium-based metal organic frameworks. The resulting In₆ S₇ /NSC HMS anode exhibits theoretical-value-close specific capacity (546.2 mAh g^-1 at 0.1 A g^-1 ), ultrahigh rate capability (267.5 mAh g^-1 at 30.0 A g^-1 ), high initial coulombic efficiency (≈93.5%), and ≈92.6% capacity retention after 4000 cycles. This kinetically favored In₆ S₇ /NSC HMS anode fills up the kinetics gap with a capacitive porous carbon cathode, enabling a sodium-ion capacitor to deliver an ultrahigh energy density of 136.3 Wh kg^-1 and a maximum power density of 47.5 kW kg^-1 . The in situ/ex situ analytical techniques and theoretical calculation both show that the robust and fast Na⁺ charge storage of In₆ S₇ /NSC HMS arises from the multi-electron redox mechanism, buffered volume expansion, negligible morphological change, and surface-controlled solid-state Na⁺ transport.

Interlayer-Expanded MoS2 Enabled by Sandwiched Monolayer Carbon for High Performance Potassium Storage

Potassium-ion batteries (PIBs) have aroused a large amount of interest recently due to the plentiful potassium resource, which may show cost benefits over lithium-ion batteries (LIBs). However, the huge volume expansion induced by the intercalation of large-sized potassium ions and the intrinsic sluggish kinetics of the anode hamper the application of PIBs. Herein, by rational design, nano-roses assembled from petals with a MoS2/monolayer carbon (C-MoS2) sandwiched structure were successfully synthesized. The interlayer distance of ultrathin C-MoS2 was expanded from original MoS2 of 6.2 to 9.6 Å due to the formation of the MoS2-carbon inter overlapped superstructure. This unique structure efficiently alleviates the mechanical strain, prevents the aggregation of MoS2, creates more active sites, facilitates electron transport, and enhances the specific capacity and K+ diffusion kinetics. As a result, the prepared C-MoS2-1 anode delivers a high reversible specific capacity (437 mAh g−1 at 0.1 A g−1) and satisfying rate performance (123 mAh g−1 at 6.4 A g−1). Therefore, this work provides new insights into the design of high-performance anode materials of PIBs.

Enhanced Kinetic Behaviors of Hollow MoO2/MoS2 Nanospheres for Sodium-Ion-Based Energy Storage

Mo-based heterostructures offer a new strategy to improve the electronics/ion transport and diffusion kinetics of the anode materials for sodium-ion batteries (SIBs). MoO₂/MoS₂ hollow nanospheres have been successfully designed via in-situ ion exchange technology with the spherical coordination compound Mo-glycerates (MoG). The structural evolution processes of pure MoO₂, MoO₂/MoS₂, and pure MoS₂ materials have been investigated, illustrating that the structureofthenanospherecan be maintained by introducing the S-Mo-S bond. Based on the high conductivity of MoO₂, the layered structure of MoS₂ and the synergistic effect between components, as-obtained MoO₂/MoS₂ hollow nanospheres display enhanced electrochemical kinetic behaviors for SIBs. The MoO₂/MoS₂ hollow nanospheres achieve a rate performance with 72% capacity retention at a current of 3200 mA g^-1 compared to 100 mA g^-1. The capacity can be restored to the initial capacity after a current returns to 100 mA g^-1, while the capacity fading of pure MoS₂ is up to 24%. Moreover, the MoO₂/MoS₂ hollow nanospheres also exhibit cycling stability, maintaining a stable capacity of 455.4 mAh g^-1 after 100 cycles at a current of 100 mA g^-1. In this work, the design strategy for the hollow composite structure provides insight into the preparation of energy storage materials.

Design of Nacre-Inspired 2D-MoS2 Nanosheets Assembled with Mesoporous Covalent Organic Frameworks (COFs) for Smart Coatings

High loading capacity and smart release of inhibitors are the first and foremost characteristics of nanocontainers, which play a pivotal role in metal active corrosion protection. The present work explores the development of novel protective nanocontainers based on recently emerged covalent organic frameworks (COFs). These highly porous frameworks with large surface area, outstanding thermomechanical properties, low density, and ease of functionalization are used as nanocontainers. On the other hand, molybdenum disulfide (MoS₂), a state-of-the-art 2D layered compound with a sheetlike structure, was utilized thanks to its excellent barrier properties. However, these lamellar structures suffer a high agglomeration tendency in polymeric matrices. Therefore, we developed a novel hybrid nanocontainer, inspired by natural nacre, by an in situ growth of COF on MoS₂ to improve the stability and provide a high inhibitor loading capacity. The porous and nitrogen-rich structure of COF made it a good carrier to adsorb europium cations as inorganic inhibitors and release them on demand by pH changes to suppress the electrochemical reactions. The as-synthesized nanoplatforms were used as pH-responsive fillers in the epoxy resin. The nanocomposite coatings showed almost 50 kΩ cm² total resistance and high impedance values (10¹¹ Ω cm²) even after 77 days of immersion. Moreover, salt spray analysis depicted the smallest amount of rust and corrosion product after 31 days in the filled nanocomposite coating. Cathodic delamination and pull-off outcomes denoted that the filled coatings with the as-synthesized nanofiller showed the smallest cathodic delamination radius (3.41 mm) and lowest adhesion loss (24%) compared to the neat epoxy (7.55 mm and 46.7%). As such, the highly porous modified MoS₂ nanosheets are considered promising alternatives in a wide range of applications with anticorrosion properties.

Co-Ion Desorption as the Main Charging Mechanism in Metallic 1T-MoS2 Supercapacitors

Metallic 1T-MoS₂ is a promising electrode material for supercapacitor applications. Its layered structure allows the efficient intercalation of ions, leading to experimental volumetric capacitance as high as 140 F/cm³. Molecular dynamics could in principle be used to characterize its charging mechanism; however, unlike conventional nanoporous carbon, 1T-MoS₂ is a multicomponent electrode. The Mo and S atoms have very different electronegativities so that 1T-MoS₂ cannot be simulated accurately using the conventional constant potential method. In this work, we show that controlling the electrochemical potential of the atoms allows one to recover average partial charges for the elements in agreement with electronic structure calculations for the material at rest, without compromising the ability to simulate systems under an applied voltage. The simulations yield volumetric capacitances in agreement with experiments. We show that due to the large electronegativity of S, the co-ion desorption is the main charging mechanism at play during the charging process. This contrasts drastically with carbon materials for which ion exchange and counterion adsorption usually dominate. In the future, our method can be extended to the study of a wide range of families of 2D layered materials such as MXenes.

Boosting Charge Transfer Via Heterostructure Engineering of Ti2 CTx /Na2 Ti3 O7 Nanobelts Array for Superior Sodium Storage Performance

The poor conductivity, inert charge transmission efficiency, and irreversible Na⁺ trapping of Na₂ Ti₃ O₇ result in retardant electrons/ions transportation and deficient sodium-ion storage efficiency, leading to sluggish reaction kinetics. To address these issues, an urchin-like Ti₂ CT_x /Na₂ Ti₃ O₇ (Ti₂ C/NTO) heterostructure sphere consisting of Ti₂ C/NTO heterostructure nanobelts array is developed via a facile one-step in situ hydrothermal strategy. The Ti₂ C/NTO heterostructure can obviously decrease Na⁺ diffusion barriers and increase electronic conductivity to improve reaction kinetics due to the built-in electric field effect and high-quantity interface region. In addition, the urchin-like vertically aligned nanobelts can reduce the diffusion distance of electrons and ions, provide favored electrolyte infiltration, adapt large volume expansion, and mitigate the aggregation to maintain structural stability during cycles, further enhancing the reaction kinetics. Furthermore, the Ti₂ C/NTO heterostructure can effectively suppress many unwanted side reactions between reactive surface sites of NTO and electrolyte as well as irreversible trapping of Na⁺ . As a result, systematic electrochemical investigations demonstrate that the Ti₂ C/NTO heterostructure as an anode material for record sodium-ion storage delivers the highest reversible capacity, the best cycling stability with 0.0065% decay rate for 4500 cycles at 2.0 A g^-1 , and excellent rate capability of 172.1 mAh g^-1 at 10.0 A g^-1 .

Innovative Materials for Energy Storage and Conversion

The metal chalcogenides (MCs) for sodium-ion batteries (SIBs) have gained increasing attention owing to their low cost and high theoretical capacity. However, the poor electrochemical stability and slow kinetic behaviors hinder its practical application as anodes for SIBs. Hence, various strategies have been used to solve the above problems, such as dimensions reduction, composition formation, doping functionalization, morphology control, coating encapsulation, electrolyte modification, etc. In this work, the recent progress of MCs as electrodes for SIBs has been comprehensively reviewed. Moreover, the summarization of metal chalcogenides contains the synthesis methods, modification strategies and corresponding basic reaction mechanisms of MCs with layered and non-layered structures. Finally, the challenges, potential solutions and future prospects of metal chalcogenides as SIBs anode materials are also proposed.

Creating Unidirectional Fast Ion Diffusion Channels in G/NiS2 -MoS2 Heterostructures for High-Performance Sodium-Ion Batteries

Exploring novel electrode composites and their unique interface physics plays a significant role in tuning electrochemical properties for boosting the performance of sodium-ion batteries (SIBs). Herein, mixed-dimensional G/NiS₂ -MoS₂ heterostructures are synthesized in a low-cost meteorological vulcanization process. The stable graphene supporting layer and nanowire heterostructure guarantee an outstanding structural stability to tolerate certain volume changes during the charge/discharge process. The rational construction of NiS₂ -MoS₂ heterostructures induces abundant interfaces and unique ion diffusion channels, which render fast electrochemical kinetics and superior reversible capacities for high-performance SIBs. Interestingly, theoretical studies reveal that the anisotropic diffusion barriers create unidirectional "high-speed" channels, which can lead to ordered and fast Na⁺ insertion/extraction in designed heterostructures. G/NiS₂ -MoS₂ anode exhibits a high capacity of 509.6 mA h g^-1 after 500 cycles and a coulombic efficiency >99% at 0.5 A g^-1 , which also displays excellent cycling performance with the capacity of 383.8 mA h g^-1 after the 1000 cycles at 5 A g^-1 . Furthermore, full cells are constructed exhibiting a high capacity of 70 mA h g^-1 at 0.1 A g^-1 after 150 cycles and applied to light LEDs. This study provides a feasible strategy of constructing mixed-dimensional heterostructures for SIBs with excellent performance and a long service lifetime.

Freestanding Ti3C2Tx MXene/Prussian Blue Analogues Films with Superior Ion Uptake for Efficient Capacitive Deionization by a Dual Pseudocapacitance Effect

Exploring and designing high-performance Faradaic electrode materials is of great significance to enhance the desalination performance of hybrid capacitive deionization (HCDI). Herein, open and freestanding films (MXene/Prussian blue analogues (PBAs), specifically, MXene/NiHCF and MXene/CuHCF) were prepared by vacuum filtration of a mixed solution of PBAs nanoparticles and a Ti₃C₂T_x MXene dispersion and directly used as HCDI electrodes. The conductive MXene nanosheets bridge the PBAs nanoparticles to form a three-dimensional (3D) conductive network structure, which can accelerate the salt ion and electron diffusion/transport kinetics for HCDI. Additionally, the PBAs nanoparticles can prevent the restacking of MXene nanosheets, expand their interlayer spacing, and facilitate the rapid diffusion and storage of ions. Benefiting from the dual pseudocapacitance and synergistic effect of PBAs and MXene, the obtained MXene/PBAs films show superior properties, with a high desalination capacity (85.1 mg g^-1 for the MXene/NiHCF film and 80.4 mg g^-1 for the MXene/CuHCF film) and an ultrafast salt-removal rate, much higher than those of other Faradaic electrodes. The synergistic effect, the adsorption of Na⁺ ions, and the enhanced conductivity of MXene/PBAs films were demonstrated through first-principles calculations. This paper offers a simple and convenient method for the design of freestanding HCDI electrodes and promotes the rapid development of HCDI technology.

Recent progress of hierarchical MoS2 nanostructures for electrochemical energy storage

Hierarchical MoS2 nanostructures are of increasing importance in energy storage via batteries or supercapacitors. Herein, the various hierarchical MoS2 materials as electrochemical electrode are reviewed in detail by classifying the...

Synergistic effect between 1D Co3S4/MoS2 heterostructures to boost the performance for alkaline overall water splitting

Reasonably designing and constructing the hetero-bimetal sulfides with high performance for oxygen/hydrogen evolution reaction (O/HER) in the alkaline electrolyte are promising but still challenging. Herein, the 1D Co3S4/MoS2 bimetallic sulfide...

Cotton textile inspires MoS2@reduced graphene oxide anodes towards high-rate capability or long-cycle stability sodium/lithium-ion batteries

Textile-based electrodes show superior energy storage performances, including high-rate capability for Na-ion batteries and long-cycling stability for Li-ion batteries, as elucidated by morphology differences that sodiation/desodiation brings intense nanomachine effect.

Interfacial Kinetics Regulation of MoS2 /Cu2 Se Nanosheets toward Superior High-Rate and Ultralong-Lifespan Sodium-Ion Half/Full Batteries

Sodium-ion batteries (SIBs) have aroused great attention because of the low cost and environmental benignity of sodium resources. However, practical applications of SIBs are plagued by the sluggish kinetics of sodium ions with large size in the host structure, which results in poor rate performance and rapid capacity decline. Herein, a self-templated approach was developed to synthesize MoS₂ /Cu₂ Se nanosheets with improved interfacial electron- and ion-transfer kinetics. The MoS₂ /Cu₂ Se nanosheets provided superior sodium storage performance, delivering 139 mAh g^-1 at a high current density of 100 A g^-1 and 222 mAh g^-1 after 14000 cycles (at 20 A g^-1 ). The outstanding electrochemical performance was attributed to the synergetic engineering of interface and structure, which could enhance the electrochemical kinetics and gave excellent mechanical properties to deal with the volume expansion phenomenon. Combined with a high-voltage cathode, the full battery demonstrated a high energy density of 152 Wh kg^-1 at a power density of 420 W kg^-1 , which opens a new avenue for the development of high-performance SIBs.

Porous Inorganic Materials for Bioanalysis and Diagnostic Applications

Porous inorganic materials play an important role in adsorbing targeted analytes and supporting efficient reactions in analytical science. The detection performance relies on the structural properties of porous materials, considering the tunable pore size, shape, connectivity, etc. Herein, we first clarify the enhancement mechanisms of porous materials for bioanalysis, concerning the detection sensitivity and selectivity. The diagnostic applications of porous material-assisted platforms by coupling with various analytical techniques, including electrochemical sensing, optical spectrometry, and mass spectrometry, etc., are then reviewed. We foresee that advanced porous materials will bring far-reaching implications in bioanalysis toward real-case applications, especially as diagnostic assays in clinical settings.

A Polymer-Assisted Spinodal Decomposition Strategy toward Interconnected Porous Sodium Super Ionic Conductor-Structured Polyanion-Type Materials and Their Application as a High-Power Sodium-Ion Battery Cathode

A general polymer-assisted spinodal decomposition strategy is used to prepare hierarchically porous sodium super ionic conductor (NASICON)-structured polyanion-type materials (e.g., Na3 V2 (PO4 )3 , Li3 V2 (PO4 )3 , K3 V2 (PO4 )3 , Na4 MnV(PO4 )3 , and Na2 TiV(PO4 )3 ) in a tetrahydrofuran/ethanol/H2 O synthesis system. Depending on the boiling point of solvents, the selective evaporation of the solvents induces both macrophase separation via spinodal decomposition and mesophase separation via self-assembly of inorganic precursors and amphiphilic block copolymers, leading to the formation of hierarchically porous structures. The resulting hierarchically porous Na3 V2 (PO4 )3 possessing large specific surface area (≈77 m2 g-1 ) and pore volume (≈0.272 cm3 g-1 ) shows a high specific capacity of 117.6 mAh g-1 at 0.1 C achieving the theoretical value and a long cycling life with 77% capacity retention over 1000 cycles at 5 C. This method presented here can open a facile avenue to synthesize other hierarchically porous polyanion-type materials.