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The utilization rate of active sites in cathode materials for Zn‐based batteries is a key factor determining the reversible capacities. However, a long‐neglected issue of the strong electrostatic repulsions among divalent Zn2+ in hosts inevitably causes the squander of some active sites (i.e. gap sites). Herein, we address this conundrum by unraveling the "gap‐filling" mechanism of multiple charge carriers in aqueous Zn‐MoS2 batteries. The tailored MoS2/(reduced graphene quantum dots) hybrid features an ultra‐large interlayer spacing (2.34 nm), superior electrical conductivity/hydrophilicity, and robust layered structure, demonstrating highly reversible NH4+/Zn2+/H+ co‐insertion/extraction chemistry in the 1 M ZnSO4+0.5 M (NH4)2SO4 aqueous electrolyte. The NH4+ and H+ ions can act as gap fillers to fully utilize the active sites and screen electrostatic interactions to accelerate the Zn2+ diffusion. Thus, unprecedentedly high rate capability (439.5 and 104.3 mAh g−1 at 0.1 and 30 A g−1, respectively) and ultra‐long cycling life (8000 cycles) are achieved. [ABSTRACT FROM AUTHOR]

V2CTx MXene is a "rising star" cathode material for aqueous zinc‐based batteries (AZBs) owing to its large/flexible interlayer spacing, rich redox chemistry of V, and high electronic conductivity. Nevertheless, the plentiful F surface terminations generated during the common preparation (fluorine‐containing acid etching process) of V2CTx generally result in high hydrophobicity, poor Zn affinity, and sluggish ion‐diffusion kinetics. Herein, a novel OH‐termination‐rich V2CTx material with interlayer "K+‐pillars" (alk‐V2CTx) is fabricated via a facile one‐step alkalization method, which features excellent hydrophilicity, expanded ion‐transport channels, and robust layered structure. Impressively, the tailored alk‐V2CTx cathode enables highly reversible and rapid Li+/Zn2+ co‐insertion/extraction electrochemistry in the formulated 15 m LiTSFI + 1 m Zn(CF3SO3)2 aqueous electrolyte, meanwhile, the "self‐exfoliation" phenomenon of MXenes upon cycling significantly increases the active sites, rendering the superior rate performance (498.2/195.1 mAh g−1 at 0.1/30 A g−1, respectively) and exceptional cycling life (96.2% capacity retention over 20 000 cycles). Systematic in situ/ex situ analyses and theoretical computations elucidate the above hybrid‐ion storage mechanisms. Finally, flexible quasi‐solid‐state rechargeable Zn batteries employing the alk‐V2CTx cathode exhibit inspiring energy output even under severe deformation conditions and low temperatures. This study provides new perspectives for designing high‐performance MXene‐based cathodes for AZBs by modulating surface terminations. [ABSTRACT FROM AUTHOR]

The meta‐analysis aimed to assess and compare the effect of closed‐incision negative pressure wound (NPW) treatment in vascular surgery. Using dichotomous or contentious random or fixed effect models, the outcomes of this meta‐analysis were examined, and the odds Ratio (OR) and the mean difference (MD) with 95% confidence intervals (CIs) were computed. Ten examinations from 2017 to 2022 were enrolled for the present meta‐analysis, including 2082 personals with vascular surgery. Closed‐incision NPW treatment had significantly lower infection rates (OR, 0.39; 95% CI, 0.30–0.51, p < 0.001), grade I infection rates (OR, 0.33; 95% CI, 0.20–0.52, p < 0.001), grade II infection rates (OR, 0.39; 95% CI, 0.21–0.71, p = 0.002), and grade III infection rates (OR, 0.31; 95% CI, 0.13–0.73, p = 0.007), and surgical re‐intervention (OR, 0.49; 95% CI, 0.25–0.97, p = 0.04) compared to control in personal with vascular surgery. However, no significant differences were found between closed‐incision NPW treatment and control in the 30‐day mortality (OR, 0.54; 95% CI, 0.29–1.00, p = 0.05), antibiotic treatment (OR, 0.53; 95% CI, 0.24–1.19, p = 0.12), and length of hospital stay (MD, −0.02; 95% CI, −0.24‐0.19, p = 0.83) in personnel with vascular surgery. The examined data revealed that closed‐incision NPW treatment had significantly lower infection rates, grade I infection rates, grade II infection rates, and grade III infection rates, surgical re‐intervention, however, there were no significant differences in 30‐day mortality, antibiotic treatment, or length of hospital stay compared to control group with vascular surgery. Yet, attention should be paid to its values since some comparisons had a low number of selected studies. [ABSTRACT FROM AUTHOR]

The development of high‐energy and long‐lifespan NASICON‐type cathode materials for sodium‐ion batteries has always been a research hotspot but a daunting challenge. Although Na4MnCr(PO4)3 has emerged as one of the most promising high‐energy‐density cathode materials owing to its three‐electron reactions, it still suffers from serious structural distortion upon repetitive charge/discharge processes caused by the Jahn‐Teller active Mn3+. Herein, the selective substitution of Cr by Zr in Na4MnCr(PO4)3 was explored to enhance the structural stability, due to the pinning effect of Zr ions and the ≈2.9‐electron reactions, as‐prepared Na3.9MnCr0.9Zr0.1(PO4)3/C delivers a high capacity retention of 85.94% over 500 cycles at 5 C and an ultrahigh capacity of 156.4 mAh g−1 at 0.1 C, enabling the stable energy output as high as 555.2 Wh kg−1. Moreover, during the whole charge/discharge process, a small volume change of only 6.7% was verified by in situ X‐ray diffraction, and the reversible reactions of Cr3+/Cr4+, Mn3+/Mn4+, and Mn2+/Mn3+ redox couples were identified via ex situ X‐ray photoelectron spectroscopy analyses. Galvanostatic intermittent titration technique tests and density functional theory calculations further demonstrated the fast reaction kinetics of the Na3.9MnCr0.9Zr0.1(PO4)3/C electrode. This work offers new opportunities for designing high‐energy and high‐stability NASICON cathodes by ion doping. [ABSTRACT FROM AUTHOR]

Oxygen vacancies (Vo) as a common structural defect play a critical and fascinating role in regulating the physico‐chemical properties of metal oxides. For the layered transitional‐metal oxides (LTMOs) used as the popular cathodes for lithium/sodium‐ion batteries (LIBs or SIBs), Vo can modulate their intrinsic multi‐scale structural properties, thereby significantly affecting the final electrochemical performance. In this concept article, we summarize the fundamental structural regulation mechanisms of Vo in lithium/sodium‐based LTMOs in terms of ligand, local, and crystal structures. Finally, the current challenges and outlooks of Vo engineering are highlighted for future development of high‐performance layered oxide cathode materials. [ABSTRACT FROM AUTHOR]

Anionic redox chemistry has aroused increasing attention in sodium‐ion batteries (SIBs) by virtue of the appealing additional capacity. However, up to now, anionic redox reaction has not been reported in the mainstream phosphate cathodes for SIBs. Herein, the ultrathin VOPO4 nanosheets are fabricated as promising cathodes for SIBs, where the oxygen redox reaction is first activated accompanied by reversible ClO4− (from the electrolyte) insertion/extraction. As a result, the VOPO4 cathode harvests a record‐high capacity (168 mAh g−1 at 0.1 C) among its counterparts ever reported. Moreover, the ClO4− insertion efficiently expands the interlayer spacing of VOPO4 and accelerates the ion diffusion, enabling an unprecedentedly high rate performance (69 mAh g−1 at 30 C). Via systematic ex situ characterizations and theoretical computations, the anionic redox chemistry and charge storage mechanism upon cycling are thoroughly elucidated. This study opens up a new avenue toward high‐energy phosphate cathodes for SIBs by triggering anionic redox reactions. [ABSTRACT FROM AUTHOR]

The irreversible issues of Zn anode stemming from dendrite growth and water‐induced erosion have severely hindered the commercialization of rechargeable aqueous Zn batteries. Herein, a hydrophobic and fast‐Zn2+‐conductive zinc hexacyanoferrate (HB‐ZnHCF) interphase layer is in situ integrated on Zn by a rapid room‐temperature wet‐chemistry method to address these dilemmas. Different from currently proposed hydrophilic inorganic cases, the hydrophobic and compact HB‐ZnHCF interphase effectively prevents the access of water molecules to Zn surface, thus avoiding H2 evolution and Zn corrosion. Moreover, the HB‐ZnHCF with large internal ion channels, strong zincophilicity, and high Zn2+ transference number (0.86) permits fast Zn2+ transport and enables smooth Zn deposition. Remarkably, the resultant HB‐ZnHCF@Zn electrode delivers unprecedented reversibility with 99.88 % Coulombic efficiency over 3000 cycles, realizes long‐term cycling over 5800 h (>8 months, 1 mA cm−2) and 1000 h (10 mA cm−2), and assures the stable operation of full Zn battery with both coin‐ and pouch‐type configurations. [ABSTRACT FROM AUTHOR]

Layered V2O5 is a star cathode material of rechargeable aqueous zinc‐based batteries (RAZBs) owing to the rich redox chemistry of vanadium, which commonly exhibits the 2D ion‐diffusion mechanism through Zn2+ (de)intercalation at edge sites but is plagued by the inert basal planes. Here, hierarchically porous V2O5 nanosheets vertically grown on carbon cloth (V2O5/C) are innovatively prepared, where the porous structure with lattice defects successfully unlocks the V2O5 basal plane to provide additional ion‐diffusion channels and abundant active sites. Thus, highly efficient and ultrafast 3D Li+/Zn2+ co‐insertion/extraction behaviors along both the c‐axis and ab plane of V2O5 are realized for the first time in the formulated 15 m LiTFSI + 1 m Zn(CF3SO3)2 aqueous electrolyte, as elucidated by systematic ex situ analyses, multiple electrochemical measurements, and theoretical computations. As a result, the porous V2O5/C electrode delivers an exceptional high‐rate capability (up to 100 A g−1) and an ultralong cycling durability (15 000 cycles) in RAZBs. Finally, quasi‐solid‐state wearable rechargeable zinc batteries employing the porous V2O5/C cathode demonstrate respectable performance even under severe deformations and low temperatures. This work achieves a conceptual breakthrough represented by an upgrading of the traditional 2D ion transportation in layered cathodes to the more facile 3D diffusion for designing high‐performance battery electrochemistry. [ABSTRACT FROM AUTHOR]

Manganese‐rich layered oxide cathodes of sodium‐ion batteries (SIBs) are extremely promising for large‐scale energy storage owing to their high capacities and cost effectiveness, while the Jahn–Teller (J–T) distortion and low operating potential of Mn redox largely hinder their practical applications. Herein, we reveal that annealing in argon rather than conventional air is a universal strategy to comprehensively upgrade the Na‐storage performance of Mn‐based oxide cathodes. Bulk oxygen vacancies are introduced via this method, leading to reduced Mn valence, lowered Mn 3d‐orbital energy level, and formation of the new‐concept Mn domains. As a result, the energy density of the model P2‐Na0.75Mg0.25Mn0.75O2 cathode increases by ≈50 % benefiting from the improved specific capacity and operating potential of Mn redox. The Mn domains can disrupt the cooperative J–T distortion, greatly promoting the cycling stability. This exciting finding opens a new avenue towards high‐performance Mn‐based oxide cathodes for SIBs. [ABSTRACT FROM AUTHOR]

Initiating anionic redox chemistry in layered sodium oxide cathodes is a prevalent method to break the capacity limit set by traditional transition metal redox. However, realizing the "win‐win" scenario of high capacity and high cycling stability is still challenging due to the high‐voltage structural distortion and irreversible oxygen loss. Herein, a Mn activation mechanism is unveiled in a novel P2‐Na0.80Li0.08Ni0.22Mn0.67O2 cathode. By elevating the charge cut‐off voltage to 4.3 V, anionic redox is successfully triggered and partial oxygen loss enables the reduction of Mn upon discharge, thus activating more Mn3+/Mn4+ redox reactions in the following cycles and maintaining the total capacity almost unchanged. In situ X‐ray diffraction reveals a complete solid‐solution reaction with an ultralow volume change of 1.04% upon cycling. Consequently, the P2‐Na0.80Li0.08Ni0.22Mn0.67O2 cathode simultaneously accomplishes a high discharge capacity (134.8 mAh g−1 at 0.1 C) and an unexpectedly long cycling life (capacity retention of 91.5% and 85.2% after 500 and 1000 cycles at 10 C, respectively). Via systematic ex situ characterizations and theoretical computations, the charge compensation mechanism upon Na+ insertion/extraction is elucidated. This work broadens the horizons of current oxygen redox chemistry and provides a new path to design high‐performance layered oxide cathode materials for sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

Proton insertion chemistry in aqueous zinc‐ion batteries (AZIBs) is becoming a research hotspot owing to its fast kinetics and additional capacities. However, H+ storage mechanism has not been deciphered in the popular MoS2‐based AZIBs. Herein, we innovatively prepared a MoS2/poly(3,4‐ethylenedioxythiophene) (MoS2/PEDOT) hybrid, where the intercalated PEDOT not only increases the interlayer spacing (from 0.62 to 1.29 nm) and electronic conductivity of MoS2, but also activates the proton insertion chemistry. Thus, highly efficient and reversible H+/Zn2+ co‐insertion/extraction behaviors are demonstrated for the first time in aqueous Zn‐MoS2 batteries. More intriguingly, the co‐inserted protons can act as lubricants to effectively shield the electrostatic interactions between MoS2/PEDOT host and divalent Zn2+, enabling the accelerated ion‐diffusion kinetics and exceptional rate performance. This work proposes a new concept of "proton lubricant" driving Zn2+ transport and broadens the horizons of Zn‐MoS2 batteries. [ABSTRACT FROM AUTHOR]

Herein, effect of heat treatment on the microstructure and mechanical properties of a newly developed Al–9Si–0.4Mg–0.1Cu alloy treated by Al–6Sr–7La is investigated, and optimal T6 heat treatment process parameters are determined through optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) analysis, and quantitative statistics. The results show that the distribution of α‐Al is more uniform after T6 heat treatment (solution treated at 540 °C for 5 h and aged at 170 °C for 6 h) with eutectic silicon possessing fine grain and high roundness. Meanwhile, Al–6Sr–7La increases peak aging hardness and reduces peak aging time. During the under‐aging process, a large amount of Guinier Preston zone and a small amount of Mg5Si6 phase precipitate, which have strengthening effect on the alloy. At peak aging state, the coherent precipitated Mg5Si6 phase in α‐Al leads to the highest microhardness. Continuing to prolong aging time, the coherent relationship between metastable phase Mg5Si6 and the matrix is weakened, resulting in the decrease in microhardness. In addition, after T6 heat treatment, both tensile strength and elongation of the alloy are significantly improved and the reasons are discussed. [ABSTRACT FROM AUTHOR]

An all‐solid‐state battery enabled by the incombustible and highly Li‐ion conductive sulfide solid‐state electrolyte, is recognized to be a strong candidate for next‐generation of lithium‐ion batteries. Intensive research efforts have been devoted to developing the well‐suited sulfide electrolytes with outstanding performances. Although several types of sulfide electrolytes have achieved superionic conductivities with excellent deformability, the air‐sensitive behaviors of them are detrimental to the large‐scale production. Considerable efforts are in progress to tackle this issue via various strategies in recent years. This review provides an overview of several classes of promising sulfide solid electrolytes. The principle and strategies for improving the resistance of these sulfide electrolytes against air are thoroughly discussed. We also point out the major challenges that all‐solid‐state batteries and different types of sulfide electrolytes face for practical applications. [ABSTRACT FROM AUTHOR]

Aqueous Zn‐ion batteries (AZIBs) are considered as promising large‐scale energy storage devices due to their high safety and low cost. Transition metal dichalcogenides (TMDs) as the potential aqueous Zn‐storage cathode materials are under the research spotlight because of their facile 2D ion‐transport channels and weak electrostatic interactions with Zn2+. In this concept article, we summarize the intrinsic structural features and aqueous Zn‐storage mechanisms of the TMDs‐based electrodes. More significantly, the latest design concepts of TMDs materials for high‐performance AZIBs are discussed in detail from three aspects of interlayer expansion engineering, phase transition engineering, and structure defects engineering. Finally, the current challenges facing TMDs cathodes and possible remedies are outlined for future developments towards efficient, rapid, and stable aqueous Zn‐ion storage. [ABSTRACT FROM AUTHOR]

Layered oxide cathodes for sodium‐ion batteries (SIBs) have drawn increasing attention owing to their fascinating additional capacity contributed by oxygen‐redox chemistry. Unfortunately, excessive oxygen redox incurs an irreversible oxygen release, deteriorating the cyclic stability and compromising the advantage of additional capacity. Significant efforts have been made so far to stabilize lattice oxygen, but the potential advantages associated with oxygen loss have been ignored. Herein, a complementary Mn and O redox mechanism is first revealed in a novel P2‐Na0.75Ca0.04[Li0.1Ni0.2Mn0.67]O2 cathode. The partial oxygen release activates more Mn3+/Mn4+ redox capacities upon cycling, which effectively compensate the capacity loss from O2‐/On‐ redox and thus enable an ultra‐stable cycling performance (capacity retentions of 102.1% and 95.2% over 100 and 200 cycles at 5 C, respectively). The fast Na+ diffusion kinetics of the cathode also ensure an exceptional rate capability (133.1 and 68.8 mAh g‐1 at 0.1 and 20 C, respectively). The electrode crystal/electronic structure evolution and charge compensation mechanism upon sodiation/desodiation have been elucidated via systematic operando measurements and theoretical computations. The complementary chemistry is a universal principle that stabilizes the Na‐storage behaviors of Mn‐based oxide cathodes, providing new opportunities for anionic redox to boost the energy density and cycling life of SIBs simultaneously. [ABSTRACT FROM AUTHOR]

Layered VS2 holds great potential as a cathode material for aqueous Zn‐ion batteries owing to its large interlayer spacing, high electrical conductivity, and the rich redox chemistry of vanadium. Nevertheless, structural instability during charge/discharge severely hinders the further development of VS2 cathodes. Herein, distinctive hierarchitectures of 1T‐VS2 nanospheres assembled by nanosheets, which feature abundant active sites, superior electron/ion transport property, and robust structure, are developed. More intriguingly, Zn2+ "pillars" residing in VS2 interlayers, achieved by controlling the charge cut‐off voltage are first proven to reinforce the layered structure of VS2 upon repeated Zn2+ insertion/extraction, redefining the commonly perceived "dead Zn2+". Hence, exceptional rate performance (212.9 and 102.1 mA h g−1 at 0.1 and 5 A g−1, respectively) and ultralong cycling life (86.7% capacity retention over 2000 cycles at 2 A g−1) are obtained. The rapid and highly reversible Zn‐ion (de) intercalation behavior within the VS2 nanospheres is verified by first‐principles computations and multiple ex‐situ characterizations. Finally, the flexible quasi‐solid‐state rechargeable Zn battery employing the tailored VS2 cathode demonstrates great application prospects in wearable devices. This work provides new perspectives for prolonging the lifespan of layered Zn‐storage materials by simply modulating the charge/discharge processes. [ABSTRACT FROM AUTHOR]

Triggering the anionic redox chemistry in layered oxide cathodes has emerged as a paradigmatic approach to efficaciously boost the energy density of sodium‐ion batteries. However, their practical applications are still plagued by irreversible lattice oxygen release and deleterious structure distortion. Herein, a novel P2‐Na0.76Ca0.05[Ni0.23□0.08Mn0.69]O2 cathode material featuring joint cationic and anionic redox activities, where native vacancies are produced in the transition‐metal (TM) layers and Ca ions are riveted in the Na layers, is developed. Random vacancies in the TM sites induce the emergence of nonbonding O 2p orbitals to activate anionic redox, which is confirmed by systematic electrochemical measurements, ex situ X‐ray photoelectron spectroscopy, in situ X‐ray diffraction, and density functional theory computations. Benefiting from the pinned Ca ions in the Na sites, a robust layered structure with the suppressed P2‐O2 phase transition and enhanced anionic redox reversibility upon charge/discharge is achieved. Therefore, the electrode displays exceptional rate capability (153.9 mA h g−1 at 0.1 C with 74.6 mA h g−1 at 20 C) and improved cycling life (87.1% capacity retention at 0.1 C after 50 cycles). This study provides new opportunities for designing high‐energy‐density and high‐stability layered sodium oxide cathodes by tuning local chemical environments. [ABSTRACT FROM AUTHOR]

Aqueous Zn‐storage behaviors of MoS2‐based cathodes mainly rely on the ion‐(de)intercalation at edge sites but are limited by the inactive basal plane. Herein, an in‐situ molecular engineering strategy in terms of structure defects manufacturing and O‐doping is proposed for MoS2 (designated as D‐MoS2‐O) to unlock the inert basal plane, expand the interlayer spacing (from 6.2 to 9.6 Å), and produce abundant 1T‐phase. The tailored D‐MoS2‐O with excellent hydrophilicity and high conductivity allows the 3D Zn2+ transport along both the ab plane and c‐axis, thus achieving the exceptional high rate capability. Zn2+ diffusion through the basal plane is verified by DFT computations. As a proof of concept, the wearable quasi‐solid‐state rechargeable Zn battery employing the D‐MoS2‐O cathode operates stably even under severe bending conditions, showing great application prospects. This work opens a new window for designing high‐performance layered cathode materials for aqueous Zn‐ion batteries. [ABSTRACT FROM AUTHOR]

Water‐in‐salt electrolytes (WISE) have largely widened the electrochemical stability window (ESW) of aqueous electrolytes by formation of passivating solid electrolyte interphase (SEI) on anode and also absorption of the hydrophobic anion‐rich double layer on cathode. However, the cathodic limiting potential of WISE is still too high for most high‐capacity anodes in aqueous sodium‐ion batteries (ASIBs), and the cost of WISE is also too high for practical application. Herein, a low‐cost 19 m (m: mol kg−1) bi‐salts WISE with a wide ESW of 2.8 V was designed, where the low‐cost 17 m NaClO4 extends the anodic limiting potential to 4.4 V, while the fluorine‐containing salt (2 m NaOTF) extends the cathodic limiting potential to 1.6 V by forming the NaF–Na2O–NaOH SEI on anode. The 19 m NaClO4–NaOTF–H2O electrolyte enables a 1.75 V Na3V2(PO4)3∥Na3V2(PO4)3 full cell to deliver an appreciable energy density of 70 Wh kg−1 at 1 C with a capacity retention of 87.5 % after 100 cycles. [ABSTRACT FROM AUTHOR]

Iron/manganese‐based layered transition metal oxides have risen to prominence as prospective cathodes for sodium‐ion batteries (SIBs) owing to their abundant resources and high theoretical specific capacities, yet they still suffer from rapid capacity fading. Herein, a dual‐strategy is developed to boost the Na‐storage performance of the Fe/Mn‐based layered oxide cathode by copper (Cu) doping and nanoengineering. The P2‐Na0.76Cu0.22Fe0.30Mn0.48O2 cathode material synthesized by electrospinning exhibits the pearl necklace‐like hierarchical nanostructures assembled by nanograins with sizes of 50–150 nm. The synergistic effects of Cu doping and nanotechnology enable high Na+ coefficients and low ionic migration energy barrier, as well as highly reversible structure evolution and Cu/Fe/Mn valence variation upon repeated sodium insertion/extraction; thus, the P2‐Na0.76Cu0.22Fe0.30Mn0.48O2 nano‐necklaces yield fabulous rate capability (125.4 mA h g−1 at 0.1 C with 56.5 mA h g−1 at 20 C) and excellent cyclic stability (≈79% capacity retention after 300 cycles). Additionally, a promising energy density of 177.4 Wh kg−1 is demonstrated in a prototype soft‐package Na‐ion full battery constructed by the tailored nano‐necklaces cathode and hard carbon anode. This work symbolizes a step forward in the development of Fe/Mn‐based layered oxides as high‐performance cathodes for SIBs. [ABSTRACT FROM AUTHOR]

Perovskite‐based light‐emitting diodes (PeLEDs) are now approaching the upper limits of external quantum efficiency (EQE); however, their application is currently limited by reliance on lead and by inadequate color purity. The Rec. 2020 requires Commission Internationale de l'Eclairage coordinates of (0.708, 0.292) for red emitters, but present‐day perovskite devices only achieve (0.71, 0.28). Here, lead‐free PeLEDs are reported with color coordinates of (0.706, 0.294)—the highest purity reported among red PeLEDs. The variation of the emission spectrum is also evaluated as a function of temperature and applied potential, finding that emission redshifts by <3 nm under low temperature and by <0.3 nm V−1 with operating voltage. The prominent oxidation pathway of Sn is identified and this is suppressed with the aid of H3PO2. This strategy prevents the oxidation of the constituent precursors, through both its moderate reducing properties and through its forming complexes with the perovskite that increase the energetic barrier toward Sn oxidation. The H3PO2 additionally seeds crystal growth during film formation, improving film quality. PeLEDs are reported with an EQE of 0.3% and a brightness of 70 cd m−2; this is the record among reported red‐emitting, lead‐free PeLEDs. [ABSTRACT FROM AUTHOR]

Layered transition metal oxides (TMOs) are appealing cathode candidates for sodium‐ion batteries (SIBs) by virtue of their facile 2D Na+ diffusion paths and high theoretical capacities but suffer from poor cycling stability. Herein, taking P2‐type Na2/3Ni1/3Mn2/3O2 as an example, it is demonstrated that the hierarchical engineering of porous nanofibers assembled by nanoparticles can effectively boost the reaction kinetics and stabilize the structure. The P2‐Na2/3Ni1/3Mn2/3O2 nanofibers exhibit exceptional rate capability (166.7 mA h g−1 at 0.1 C with 73.4 mA h g−1 at 20 C) and significantly improved cycle life (≈81% capacity retention after 500 cycles) as cathode materials for SIBs. The highly reversible structure evolution and Ni/Mn valence change during sodium insertion/extraction are verified by in operando X‐ray diffraction and ex situ X‐ray photoelectron spectroscopy, respectively. The facilitated electrode process kinetics are demonstrated by an additional study using the electrochemical measurements and density functional theory computations. More impressively, the prototype Na‐ion full battery built with a Na2/3Ni1/3Mn2/3O2 nanofibers cathode and hard carbon anode delivers a promising energy density of 212.5 Wh kg−1. The concept of designing a fibrous framework composed of small nanograins offers a new and generally applicable strategy for enhancing the Na‐storage performance of layered TMO cathode materials. [ABSTRACT FROM AUTHOR]

Abstract: Maricite NaFePO4 nanodots with minimized sizes (≈1.6 nm) uniformly embedded in porous N‐doped carbon nanofibers (designated as NaFePO4@C) are first prepared by electrospinning for maximized Na‐storage performance. The obtained flexible NaFePO4@C fiber membrane adherent on aluminum foil is directly used as binder‐free cathode for sodium‐ion batteries, revealing that the ultrasmall nanosize effect as well as a high‐potential desodiation process can transform the generally perceived electrochemically inactive maricite NaFePO4 into a highly active amorphous phase; meanwhile, remarkable electrochemical performance in terms of high reversible capacity (145 mA h g−1 at 0.2 C), high rate capability (61 mA h g−1 at 50 C), and unprecedentedly high cyclic stability (≈89% capacity retention over 6300 cycles) is achieved. Furthermore, the soft package Na‐ion full battery constructed by the NaFePO4@C nanofibers cathode and the pure carbon nanofibers anode displays a promising energy density of 168.1 Wh kg−1 and a notable capacity retention of 87% after 200 cycles. The distinctive 3D network structure of very fine NaFePO4 nanoparticles homogeneously encapsulated in interconnected porous N‐doped carbon nanofibers, can effectively improve the active materials' utilization rate, facilitate the electrons/Na+ ions transport, and strengthen the electrode stability upon prolonged cycling, leading to the fascinating Na‐storage performance. [ABSTRACT FROM AUTHOR]

Ti2AlNb‐based alloys are synthesized by spark plasma sintering from pre‐alloyed and ball‐milled Ti–22Al–25Nb powder, and the structure of the alloys is regulated by aging at 800 °C for 0.5, 1, 2, and 3 h. Comparison of phase composition, microstructure, and mechanical properties are made in this study. Aging in the B2 + O phase region refers to the reversible transformation of B2 ↔ O. Complete B2 + O Widmanstätten structure is obtained in the aged alloys synthesized from pre‐alloyed powder, and the ones from milled powder contain acicular O and B2 + O Widmanstätten structure. Ball milling eliminates the B2 + O colonies, facilitates the continuous transformation of O → B2, and induces acicular O in the alloys; however, the hardness of these alloys is decreased in contrast with that of the ones synthesized from pre‐alloyed powder. Owing to the precipitation strengthening based on a large amount of fine O‐phase precipitates, the 3 h aged alloy from pre‐alloyed powder exhibits comprehensive mechanical properties with Vickers hardness of 448 ± 9 HV, ultimate tensile strength of 730 MPa, and elongation of 0.43%. [ABSTRACT FROM AUTHOR]

NaVPO4F has received a great deal of attention as cathode material for Na-ion batteries due to its high theoretical capacity (143 mA h g−1), high voltage platform, and structural stability. Novel NaVPO4F/C nanofibers are successfully prepared via a feasible electrospinning method and subsequent heat treatment as self-standing cathode for Na-ion batteries. Based on the morphological and microstructural characterization, it can be seen that the NaVPO4F/C nanofibers are smooth and continuous with NaVPO4F nanoparticles (≈6 nm) embedded in porous carbon matrix. For Na-storage, this electrode exhibits extraordinary electrochemical performance: a high capacity (126.3 mA h g−1 at 1 C), a superior rate capability (61.2 mA h g−1 at 50 C), and ultralong cyclability (96.5% capacity retention after 1000 cycles at 2 C). 1D NaVPO4F/C nanofibers that interlink into 3D conductive network improve the conductivity of NaVPO4F, and effectively restrain the aggregation of NaVPO4F particles during charge/discharge process, leading to the high performance. [ABSTRACT FROM AUTHOR]

Lithium metal is considered a "Holy Grail" of anode materials for high-energy-density batteries. However, both dendritic lithium deposition and infinity dimension change during long-term cycling have extremely restricted its practical applications for energy storage devices. Here, a thermal infusion strategy for prestoring lithium into a stable nickel foam host is demonstrated and a composite anode is achieved. In comparison with the bare lithium, the composite anode exhibits stable voltage profiles (200 mV at 5.0 mA cm-2) with a small hysteresis beyond 100 cycles in carbonate-based electrolyte, as well as high rate capability, significantly reduced interfacial resistance, and small polarization in a full-cell battery with Li4Ti5O12 or LiFePO4 as counter electrode. More importantly, in addition to the fact that lithium is successfully confined in the metallic nickel foam host, uniform lithium plating/stripping is achieved with a low dimension change (merely ≈3.1%) and effective inhibition of dendrite formation. The mechanism for uniform lithium stripping/plating behavior is explained based on a surface energy model. [ABSTRACT FROM AUTHOR]

We report the synthesis and anode application for sodium-ion batteries (SIBs) of WS2 nanowires (WS2 NWs). WS2 NWs with very thin diameter of ≈25 nm and expanded interlayer spacing of 0.83 nm were prepared by using a facile solvothermal method followed by a heat treatment. The as-prepared WS2 NWs were evaluated as anode materials of SIBs in two potential windows of 0.01-2.5 V and 0.5-3 V. WS2 NWs displayed a remarkable capacity (605.3 mA h g−1 at 100 mA g−1) but with irreversible conversion reaction in the potential window of 0.01-2.5 V. In comparison, WS2 NWs showed a reversible intercalation mechanism in the potential window of 0.5-3 V, in which the nanowire-framework is well maintained. In the latter case, the interlayers of WS2 are gradually expanded and exfoliated during repeated charge-discharge cycling. This not only provides more active sites and open channels for the intercalation of Na+ but also facilitates the electronic and ionic diffusion. Therefore, WS2 NWs exhibited an ultra-long cycle life with high capacity and rate capability in the potential window of 0.5-3 V. This study shows that WS2 NWs are promising as the anode materials of room-temperature SIBs. [ABSTRACT FROM AUTHOR]

A simple and template-free method for preparing three-dimensional (3D) porous γ-Fe2O3@C nanocomposite is reported using an aerosol spray pyrolysis technology. The nanocomposite contains inner-connected nanochannels and γ-Fe2O3 nanoparticles (5 nm) uniformly embedded in a porous carbon matrix. The size of γ-Fe2O3 nanograins and carbon content can be controlled by the concentration of the precursor solution. The unique structure of the 3D porous γ-Fe2O3@C nanocomposite offers a synergistic effect to alleviate stress, accommodate large volume change, prevent nanoparticles aggregation, and facilitate the transfer of electrons and electrolyte during prolonged cycling. Consequently, the nanocomposite shows high-rate capability and long-term cyclability when applied as an anode material for Na-ion batteries (SIBs). Due to the simple one-pot synthesis technique and high electrochemical performance, 3D porous γ-Fe2O3@C nanocomposites have a great potential as anode materials for rechargeable SIBs. [ABSTRACT FROM AUTHOR]

Although transition metal oxide electrodes have large lithium storage capacity, they often suffer from low rate capability, poor cycling stability, and unclear additional capacity. In this paper, CoO nanowire clusters (NWCs) composed of ultra-small nanoparticles (≈10 nm) directly grown on copper current collector are fabricated and evaluated as an anode of binder-free lithium-ion batteries, which exhibits an ultra-high capacity and good rate capability. At a rate of 1 C (716 mA g−1), a reversible capacity as high as 1516.2 mA h g−1 is obtained, and even when the current density is increased to 5 C, a capacity of 1330.5 mA h g−1 could still be maintained. Importantly, the origins of the additional capacity are investigated in detail, with the results suggesting that pseudocapacitive charge and the higher-oxidation-state products are jointly responsible for the large additional capacity. In addition, nanoreactors for the CoO nanowires are fabricated by coating the CoO nanowires with amorphous silica shells. This hierarchical core-shell CoO@SiO2 NWC electrode achieves an improved cycling stability without degrading the high capacity and good rate capability compared to the uncoated CoO NWCs electrode. [ABSTRACT FROM AUTHOR]

To develop a long cycle life and good rate capability electrode, 3D hierarchical porous α-Fe2O3 nanosheets are fabricated on copper foil and directly used as binder-free anode for lithium-ion batteries. This electrode exhibits a high reversible capacity and excellent rate capability. A reversible capacity up to 877.7 mAh g−1 is maintained at 2 C (2.01 A g−1) after 1000 cycles, and even when the current is increased to 20 C (20.1 A g−1), a capacity of 433 mA h g−1 is retained. The unique porous 3D hierarchical nanostructure improves electronic-ionic transport, mitigates the internal mechanical stress induced by the volume variations of the electrode upon cycling, and forms a 3D conductive network during cycling. No addition of any electrochemically inactive conductive agents or polymer binders is required. Therefore, binder-free electrodes further avoid the uneven distribution of conductive carbon on the current collector due to physical mixing and the addition of an insulator (binder), which has benefits leading to outstanding electrochemical performance. [ABSTRACT FROM AUTHOR]

Designed as a high-capacity, high-rate, and long-cycle life anode for sodium-ion batteries, ultrasmall Sn nanoparticles (≈8 nm) homogeneously embedded in spherical carbon network (denoted as 8-Sn@C) is prepared using an aerosol spray pyrolysis method. Instrumental analyses show that 8-Sn@C nanocomposite with 46 wt% Sn and a BET surface area of 150.43 m2 g−1 delivers an initial reversible capacity of ≈493.6 mA h g−1 at the current density of 200 mA g−1, a high-rate capacity of 349 mA h g−1 even at 4000 mA g−1, and a stable capacity of ≈415 mA h g−1 after 500 cycles at 1000 mA g−1. The remarkable electrochemical performance of 8-Sn@C is owing to the synergetic effects between the well-dispersed ultrasmall Sn nanoparticles and the conductive carbon network. This unique structure of very-fine Sn nanoparticles embedded in the porous carbon network can effectively suppress the volume fluctuation and particle aggregation of tin during prolonged sodiation/desodiation process, thus solving the major problems of pulverization, loss of electrical contact and low utilization rate facing Sn anode. [ABSTRACT FROM AUTHOR]

The construction of bifunctional electrode materials for hydrogen evolution reaction (HER) and lithium‐ion batteries (LIBs) has been a hot topic of research. Herein, metal–organic frameworks (MOFs) derived micro‐/nanostructured Ni2P/Ni hybrids with a porous carbon coating (denoted as Ni2P/Ni@C) are prepared using a feasible pyrolysis–phosphidation strategy. On the one hand, the optimal Ni2P/Ni@C catalyst exhibits superior HER performance with a low overpotential of 149 mV versus a reversible hydrogen electrode (RHE) at 10 mA cm−2 and excellent durability. The density functional theory computations verify that the strong synergistic effect between Ni2P and Ni could optimize the electronic structure, thus rendering the enhanced electrocatalytic performance. On the other hand, the Ni2P/Ni@C electrode displays a reversible capacity of 597 mAh g−1 after 1000 cycles at 1000 mA g−1 and improved rate capability as an anode for LIBs, owing to the well‐organized micro‐/nanostructure and conductive Ni core. In addition, the electrochemical reaction mechanism of the Ni2P/Ni@C electrode upon lithiation/delithiation is investigated in detail via ex situ X‐ray powder diffraction and X‐ray photoelectron spectroscopy methods. It is expected that the facile and controllable approach can be extended to fabricate other MOF‐based metal phosphides/metal hybrids for electrochemical energy storage and conversion systems. [ABSTRACT FROM AUTHOR]

In this paper, the synthesis of ultrasmall Na2FePO4F nanoparticles (≈3.8 nm) delicately embedded in porous N‐doped carbon nanofibers (denoted as Na2FePO4F@C) by electrospinning is reported. The as‐prepared Na2FePO4F@C fiber film tightly adherent on aluminum foil features great flexibility and is directly used as binder‐free cathode for sodium‐ion batteries, exhibiting admirable electrochemical performance with high reversible capacity (117.8 mAh g−1 at 0.1 C), outstanding rate capability (46.4 mAh g−1 at 20 C), and unprecedentedly high cyclic stability (85% capacity retention after 2000 cycles). The reaction kinetics and mechanism are explored by a combination study of cyclic voltammetry, ex situ structure/valence analyses, and first‐principles computations, revealing the highly reversible phase transformation of Na2FeIIPO4F ↔ NaFeIIIPO4F, the facilitated Na+ diffusion dynamics with low energy barriers, and the desirable pseudocapacitive behavior for fast charge storage. Pouch‐type Na‐ion full batteries are also assembled employing the Na2FePO4F@C nanofibers cathode and the carbon nanofibers anode, demonstrating a promising energy density of 135.8 Wh kg−1 and a high capacity retention of 84.5% over 200 cycles. The distinctive network architecture of ultrafine active materials encapsulated into interlinked carbon nanofibers offers an ideal platform for enhancing the electrochemical reactivity, electronic/ionic transmittability, and structural stability of Na‐storage electrodes. [ABSTRACT FROM AUTHOR]

In this study, the dissimilar S31042 and S34700 austenitic stainless steels joints are welded with linear friction welding (LFW). The history of shear stress at the interface and axial shortening during LFW, the microstructure evolution and mechanical properties of the joint are studied. Results show that axial shortening develops during the equilibrium and deceleration phases. The shear stress reaches a maximum during deceleration as a metallurgical bond forms in sections of the interface. The weld center zone is a narrow layer with a thickness of about 380 µm, where there are fine equiaxed grains with a strong {112}<110> texture. Elongated grains are present in the thermo‐mechanically affected zone due to the shear stress. The average tensile strength and elongation of the joints are measured to be 577 MPa and 33.3%, respectively. All tensile test samples fail at the base material of S34700, as the tensile strength of the joint is equal to or better than that of the base S34700. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous zinc batteries have gained considerable attention for large‐scale energy storage systems because of their low cost and high safety, but they suffer from limitations in cycling stability and energy density with advanced cathode materials. Here, a high‐performance V5O12·6H2O (VOH) nanobelt cathode uniformly located on a stainless‐steel substrate via a facile electrodeposition technique is reported. We show that the hydrated layered VOH cathode enables highly reversible and ultrafast Zn2+ cation (de)intercalation processes, as confirmed by various electrochemical, X‐ray diffraction, X‐ray photoelectron spectroscopy, and transmission electron microscopy analyses. It is demonstrated that the binder‐free VOH cathode can deliver a discharge capacity of 354.8 mAh g−1 at 0.5 A g−1 with a high initial Coulombic efficiency of 99.5%, a high energy density of 194 Wh kg−1 at 2100 W kg−1, and a long cycle life with a capacity retention of 94% over 1000 cycles. In addition, a flexible quasi‐solid‐state Zn–VOH battery is constructed, achieving a reversible capacity of ≈300 mAh g−1 with a capacity retention of 96% after 50 cycles and displaying excellent electrochemical behaviors under different bending states. This work sheds light on the development of rechargeable aqueous zinc batteries for stationary grid storage applications or flexible energy storage devices. V5O12·6H2O nanobelts self‐supported on a stainless‐steel substrate are prepared by electrodeposition and applied as a binder‐free cathode for rechargeable aqueous zinc batteries. The V5O12·6H2O cathode with a large layered structure (≈1.18 nm) enables highly reversible Zn2+ (de)intercalation, and displays a high energy density (194 Wh kg‐1 at 2100 W kg‐1) and a long cycling life (94% retention after 1000 cycles). [ABSTRACT FROM AUTHOR]

Deformation mechanism of L12‐γ′ phase in bimodal γ″‐γ′ precipitation hardened Inconel 718 alloy is characterized through high resolution transmission electron microscopy (HRTEM) observations. The spherical γ′ particle exhibits morphological transition toward ellipsoid along the <110> direction and shows deformation anisotropy leading to orientation‐dependent lattice misfitting status with γ‐matrix. The deformation process of γ′ phase is determined to be of APB (anti‐phase boundary)‐type shearing induced by gliding of paired {100}a/2<1¯10> superpartial dislocations, thus γ′ phase plays a APB‐strengthening role in Inconel 718 alloy. Deformation mechanism of γ′ phase in Inconel 718 alloy is characterized through high‐resolution TEM observations. The spherical γ′ particle exhibits deformation anisotropy leading to orientation‐dependent lattice misfitting status with γ‐matrix. Based on the emergence of symmetrical superlattice reflections on FFT patterns, the L12‐γ′ lattice distortion is determined to be induced by gliding of APB‐paired {100}a/2<1¯10> dislocations. [ABSTRACT FROM AUTHOR]

The unique structure of very‐fine Sn nanoparticles (≈8 nm) embedded in porous spherical carbon network (denoted as 8‐Sn@C), which is prepared on page 214 by L. Jiao, J. Chen, and co‐workers using an aerosol spray pyrolysis method, can effectively suppress the volume fluctuation and particle aggregation of tin during prolonged sodiation/desodiation process and thus show high performance as anode of sodium‐ion batteries. [ABSTRACT FROM AUTHOR]