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The performance of lithium metal batteries is severely hampered by uncontrollable dendrite growth and volume change within the anode. This work addresses these obstacles by introducing a novel strategy: applying an isotropic and internal grain-boundary-free layer, specifically, a metal-organic framework (MOF) glass layer with nano-porosity onto the electrochemically plated lithium metal anode. Both ab initio and classical molecular dynamics simulations indicate that the MOF glass layer makes the lithium transport smooth and uniform via its internal monolithic and interfacial advantages. This MOF glass layer with the fast and more uniform lithium diffusion in the monolithic interior and its interface enables dendrite-free lithium plating and stripping through surface confinement effect and interfacial effect. When employed in symmetric batteries, the achieved Li metal anode can operate over 300 h at 1 mA cm-2. The full batteries matched with LiFePO4 exhibit high capacity (148 mAh g-1), excellent rate performance (61 mAh g-1 at 5 C), and outstanding cycling stability (with capacity retention of ≈90% after 1000 cycles). The full batteries matched with high-voltage LiCoO2 also show superior performances. Therefore, the strategy of utilizing a MOF glass layer enables the development of high-performance lithium metal anodes.
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Rechargeable aqueous Zn batteries have the edge in resource reserve, cost, energy and conversion efficiency due to the inherent features of metal Zn anodes. However, the application of Zn-based batteries is being seriously hindered by Zn dendrites and water-induced side-reactions. Here, potassium polyacrylate (K-PAM) is proposed as the electrolyte additive to form a synergistic cation-anion interface on Zn surface. The carboxyl anions and K+ cations are preferentially adsorbed on the Zn surface due to the intrinsic surfactant characteristics, which could homogenize Zn plating and suppress parasitic reactions. The synergistic regulation of K-PAM additive endows the ZnZn symmetric cells with excellent cyclic durability of 1250 h at 1 mA cm-2, which is significantly better than the polyacrylic acid additive only with carboxyl anions. Moreover, trace K-PAM addition into traditional ZnSO4 electrolyte endows the ZnCu batteries with a considerable average Coulombic efficiency of 99.2 %. Additionally, higher capacity retention and excellent cycling stability of ZnVO2 cells further mark K-PAM as a potentially impressive aqueous electrolyte additive for high-performance Zn-based batteries. This work will provide a promising method for the synergistic regulation with cations and anions of electrolyte additives to improve the stability and reversibility of Zn anodes.
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Lithium-ion and post-lithium-ion batteries are important components for building sustainable energy systems. They usually consist of a cathode, an anode, an electrolyte, and a separator. Recently, the use of solid-state materials as electrolytes has received extensive attention. The solid-state electrolyte materials (as well as the electrode materials) have traditionally been overwhelmingly crystalline materials, but amorphous (disordered) materials are gradually emerging as important alternatives because they can increase the number of ion storage sites and diffusion channels, enhance solid-state ion diffusion, tolerate more severe volume changes, and improve reaction activity. To develop superior amorphous battery materials, researchers have conducted a variety of experiments and theoretical simulations. This review highlights the recent advances in using amorphous materials (AMs) for fabricating lithium-ion and post-lithium-ion batteries, focusing on the correlation between material structure and properties (e.g., electrochemical, mechanical, chemical, and thermal ones). We review both the conventional and the emerging characterization methods for analyzing AMs and present the roles of disorder in influencing the performances of various batteries such as those based on lithium, sodium, potassium, and zinc. Finally, we describe the challenges and perspectives for commercializing rechargeable AMs-based batteries.
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Polymers are promising candidates as solid-state electrolytes due to their performance and processability, but fillers play a critical role in adjusting the polymer network structure and electrochemical, thermal, and mechanical properties. Most fillers studied so far are anisotropic, limiting the possibility of homogeneous ion transport. Here, applying metal-organic framework (MOF) glass as an isotropic functional filler, solid-state polyethylene oxide (PEO) electrolytes are prepared. Calorimetric and diffusion kinetics tests show that the MOF glass addition reduces the glass transition temperature of the polymer phase, improving the mobility of the polymer chains, and thereby facilitating lithium (Li) ion transport. By also incorporating the lithium salt and ionic liquid (IL), Li-Li symmetric cell tests of the PEO-lithium salt-MOF glass-IL electrolyte reveal low overpotential, indicating low interfacial impedance. Simulations show that the isotropic structure of the MOF glass facilitates the wettability of the IL by enhancing interfacial interactions, leading to a less confined IL structure that promotes Li-ion mobility. Finally, the obtained electrolyte is used to construct Li-lithium iron phosphate full batteries that feature high cycle stability and rate capability. This work therefore demonstrates how an isotropic functional filler can be used to enhance the electrochemical performance of solid-state polymer electrolytes.
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Aqueous zinc-ion batteries have received continuous interests because of applying low-cost and eco-friendly aqueous electrolytes and having high safety. Beyond energetically to explore new-type cathode materials, it is of great significance to regulate the zinc storage behavior of the existing cathodes in order to understand the underlying working mechanism. Therefore, as a proof of concept, this work achieves the regulation of zinc storage behaviors of the tunnel structure tunnel structure B-phase vanadium dioxide (VO2 (B)) and vanadium oxide (V6 O13 ) cathodes via a simple chemical tungsten-doping induction approach. Under low-concentration tungsten-doping induction of 1, 2 and 3 at.%, the tunnel sizes of VO2 (B) can be controlled readily. Moreover, the V6 O13 with large size tunnels can be achieved by medium-concentration tungsten induction of 6 and 9 at.%. It is demonstrated that tungsten induced VO2 (B) can achieve zinc storage without lattice structure change via operando X-ray diffraction analyses. Remarkably, via operando and non-operando analyses, tungsten induced V6 O13 with lager size tunnels can realize the oriented 1D zinc ion intercalation/deintercalation. The further kinetics analysis shows that the zinc storage is mainly diffusion control, which is different from most of vanadium-based cathodes with capacitance control. This viable tungsten-doping induction strategy provides a new insight into achieving the controllable regulation of zinc storage behaviors.
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A defect-rich 2D p-n heterojunction, Cox Ni3- x (HITP)2 /BNSs-P (HITP: 2,3,6,7,10,11-hexaiminotriphenylene), is constructed using a semiconductive metal-organic framework (MOF) and boron nanosheets (BNSs) by in situ solution plasma modification. The heterojunction is an effective catalyst for the electrocatalytic nitrogen reduction reaction (eNRR) under ambient conditions. Interface engineering and plasma-assisted defects on the p-n Cox Ni3-x (HITP)2 /BNSs-P heterojunction led to the formation of both Co-N3 and B O dual-active sites. As a result, Cox Ni3-x (HITP)2 /BNSs-P has a high NH3 yield of 128.26 ± 2.27 µg h-1 mgcat. -1 and a Faradaic efficiency of 52.92 ± 1.83% in 0.1 m HCl solution. The catalytic mechanism for the eNRR is also studied by in situ FTIR spectra and DFT calculations. A Cox Ni3- x (HITP)2 /BNSs-P-based Zn-N2 battery achieved an unprecedented power output with a peak power density of 5.40 mW cm-2 and an energy density of 240 mA h gzn -1 in 0.1 m HCl. This study establishes an efficient strategy for the rational design, using defect and interfacial engineering, of advanced eNRR catalysts for ammonia synthesis under ambient conditions.
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The tunnel structure of the bronze phase vanadium dioxide (VO2(B)) can be used as the zinc ion storage active sites. However, the intense charge repulsion of divalent Zn2+ causes a sluggish reaction kinetics in the tunnel VO2(B). Here, a tungsten-oxygen bond pre-introduced (TOBI) approach is proposed to modulate the tunnel structure of VO2(B). The VO2(B) cathodes with TOBI of 0.5 at% to 3.0 at% have been controllably synthesized by a simple hydrothermal method. The results from structural analysis uncover that the pre-introduced W6+ replaces the V4+ in VO2(B) to form WO6 octahedra. Benefiting from the rapid diffusion kinetics, enhanced structural stability and improved conductivity enabled by the TOBI, the optimal VO2(B) nanoribbons with 1.5 at% shows a high reversible capacity of 265 mAh g-1, a high rate-performance of up-to 10 A g-1 and a long cycling stability of 2000 cycles. Moreover, a pseudo-capacitive dominated Zn2+ intercalation/de-intercalation behavior is solidly determined by the electrochemical kinetics testing and structural characterizations. This TOBI method is referential for developing other multivalent ion battery cathodes with outstanding performances.
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A one-step side-by-side 3D printing method is proposed to construct linear lithium-, sodium-, and zinc-ion full batteries with high electrochemical performance. The inks of the battery components present shear thinning characteristics and can be printed on different substrates. This approach to design high performance linear full batteries is a general strategy.
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Despite the fact that solid-state electrolytes have attracted broad research interests, the limited ion transfer and high interface impedance restrain their application in high-performance batteries with high cyclic stability and power density. Here, a new quasi-solid-state polymer electrolyte containing lightweight semiconducting hydrogenated borophene (HB) nanosheets, ionic liquids, and poly (ethylene oxide) is reported. The cyclic overpotential of the Li-Li symmetrical battery is about 65 mV lower than that of HB-free quasi-solid-state electrolyte, demonstrating the lower interface impedance. The interaction between lithium-ion and ethylene-oxide chains decreases owing to the existence of HB nanosheets and ionic liquids, which facilitates lithium-ion diffusion. The lithium bis(trifluoromethanesulfonyl)imide molecule surface adsorption at the HB nanosheets enhances the dissociation of lithium ions, and thus the matched lithium iron phosphate/Li full cell delivers the acceptable rate performance up to 5C. This work provides a new filler candidate to enhance the ionic conductivity of quasi-solid-state electrolytes that may facilitate to construct the high-performance HB nanosheets and ionic liquids-based lithium metal batteries.
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Since the Corona Virus Disease 2019 (COVID-19) outbreak, the normalization of the epidemic has posed great challenge to epidemic prevention and control in indoor environment. Ventilation systems are commonly used to prevent and control indoor transmission of disease. However, most naturally ventilated rooms are not efficient to prevent the spread of virus, i.e., classrooms. The goal of this work is to effectively adopt forced interference strategies (e.g., airflow deflector) applied to external windows to strengthen airflow diffusion performance (ADP) of natural ventilation. So far, no systematic study has been done to investigate the effectiveness of such airflow deflectors on its influence on natural ventilation and effectiveness of preventing the disease transmission in indoor environment. In this work, a case study was conducted based on cross-ventilated classrooms. Different settings of airflow deflectors (i.e., size and installation angle) were applied to the external windows. Air Diffusion Performance Index (ADPI) was utilized to evaluated airflow diffusion performance under different settings of the airflow deflectors. Then, the Wells-Riley model was applied to evaluate infection risk. According to the results, the infection risk can be reduced by 19.29% when infection source is located at the center of classroom and 17.47% when source is located near the side walls. This work would provide guidance for the design of classrooms ventilated with induced natural wind for epidemic prevention and control.
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It is always challenging to fabricate two-dimensional transition-metal dichalcogenides into multiple hollow micro-/nanostructures with improved properties for various potential applications. Here, hierarchically porous MoS2-C hollow rhomboids (MCHRs) have been creatively synthesized via a facile self-templated solvothermal approach. It has been clarified that the obtained MCHRs assembled beneath ultrathin γ-MnS and carbon cohybridized MoS2 nanosheets under the structural direction of the MnMoO4·0.49H2O self-template. The prepared MCHR anode of sodium-ion batteries exhibited a reversible capacity of 506 mA h g-1 at 0.1 A g-1, ultrahigh rate capabilities up to 10 A g-1 with 310 mA h g-1, and exceptional stability over 3000 cycles. This study provides inspiration for the rational design of hierarchically porous hollow nanostructures with specific geometries as an excellent electrode material for outstanding performance energy storage equipment.
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Owing to the intense charge repulsion of multivalent ions and intrinsic slugggish kenetics, vast and fast storage of zinc ions into electrode materials has remained unattainable. Here, an efficient strategy to unlock the electrochemical activity of rocksalt vanadium oxynitride is developed via the substitution of low-valent oxygen for high-valent nitrogen, forming disordered rocksalt with abundant vacancies/defects due to the charge-compensating function. Unexpectedly, the disordered rocksalt not only provides plentiful active sites for zinc ions but is also beneficial for the rapid diffusion of zinc ions, owing to the large presence of vacancies/defects in the matrix. Hence, a very high reversible capacity (603 mAh g-1 , 0.2C) and high rate capability (124 mAh g-1 at 600C) are achieved for zinc storage. This should open a new and efficient avenue for the design of electrode materials with both high energy and power densities for aqueous zinc-ion batteries.
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Rechargeable nickel-zinc battery is regarded as a prospective choice for next-generation energy storage device due to its good safety, environmental friendliness and high energy density. However, zinc anode inevitably suffers from uncontrollable growth of zinc dendrites and the dissolution of zinc metal in high-concentration alkaline electrolytes, resulting in poor cycle stability and severely hampering the widespread applications of nickel-zinc batteries. Herein, a unique zinc anode with artificial solid electrolyte interface (ASEI) is facilely constructed via the rolling-tearing of tin and zinc foils and subsequent surface-based chemical reaction in a lead salt solution. The as-prepared ASEI composed of lead film has an efficient protective effect on preventing the dissolution of zinc anode. Meanwhile, the lead element and residual tin can not only enhance hydrogen evolution over-potential of zinc anode but affect the zinc growth mechanism. As a consequence, an excellent cyclic performances upto 100â¯cycles (capacity retention: 90%) with high reversible capacities are achieved for the zinc anode with AESI.
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Although rechargeable aqueous zinc-ion batteries have attracted extensive interest due to their environmental friendliness and low cost, they still lack suitable cathodes with high rate capabilities, which are hampered by the intense charge repulsion of bivalent Zn2+ . Here, a novel intercalation pseudocapacitance behavior and ultrafast kinetics of Zn2+ into the unique tunnels of VO2 (B) nanofibers in aqueous electrolyte are demonstrated via in situ X-ray diffraction and various electrochemical measurements. Because VO2 (B) nanofibers possess unique tunnel transport pathways with big sizes (0.82 and 0.5 nm2 along the b- and c-axes) and little structural change on Zn2+ intercalation, the limitation from solid-state diffusion in the vanadium dioxide electrode is eliminated. Thus, VO2 (B) nanofibers exhibit a high reversible capacity of 357 mAh g-1 , excellent rate capability (171 mAh g-1 at 300 C), and high energy and power densities as applied for zinc-ion storage.
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Effects of water on a catalytic reaction system for reductive alkylation of p-aminodiphenylamine (p-ADPA) with 5-methyl-2-hexanone (MIAK) was studied. Platinum nanoparticles supported on activated carbon with high specific surface area were used as catalysts for reductive alkylation reaction under different water content conditions. Schiff base forming data, catalytic activity and stability of the catalysts were investigated under the aforementioned reaction conditions. Fresh and used catalysts were characterized by TEM, SEM, XRD, ICP, laser particle size analysis, N2 physical adsorption and CO chemical adsorption to explore the effects of water on the catalytic reaction system for the ketone/amine reductive alkylation reaction. The characterization results indicated that catalyst support pulverization and Pt loss occurred in the reused catalyst, and the trend was more obvious under the conditions of higher water content. Water in the reaction system could also aggravate the decrease of the catalyst's specific surface area and pore volume, which should be a major reason of the lower catalytic performance.
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Exploring 3D printing in the field of sodium-ion batteries is a great challenge since conventionally inks cause unavoidably compact filaments or frameworks, which significantly hamper the infiltration of electrolyte and diffusion of big-size sodium ions (1.02 Å), resulting in low reversible capacities. Here, new hierarchical porous frameworks are 3D printed for sodium storage by employing well-designed GO-contained inks. The resultant frameworks possess continuous filaments, hierarchical multihole gridding. Such distinct properties render these frameworks able to facilitate the fast transportation of both sodium ion and electron. As a result, 3D-printed hierarchical porous frameworks reveal the high specific capacity as well as rate performance and periodic steadiness for up to 900 cycles for sodium storage.
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Tuberculosis (TB) is a lift-threatening chronic deadliest infectious disease caused predominantly by Mycobacterium tuberculosis (MTB) which affects primarily the lungs (pulmonary TB) apart from other vital organs. The emergence of drug-resistant TB (DR-TB), multidrug-resistant TB (MDR-TB), extensively drug-resistant TB (XDR-TB) and the recently cases of totally drug resistant (TDR) towards currently accessible standard drugs was increased up to alarming level in the recent decades. In pursuit of searching new anti-TB agents, numerous of derivatives have been synthesized and screened for their anti-TB activity. Coumarins are one of the most important classes of natural products that exhibited various biological activities, and their derivatives regarded as a new class of effective anti-TB candidates owing to their potential anti-TB activity. Thus, coumarin skeleton has attracted great interest in the development of new anti-TB agents. This review outlines the advances in the application of coumarin-containing derivatives as anti-TB agents and the critical aspects of design and structure-activity relationship of these derivatives.
Assuntos
Antituberculosos/farmacologia , Cumarínicos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/tratamento farmacológico , Antituberculosos/síntese química , Antituberculosos/química , Cumarínicos/síntese química , Cumarínicos/química , Desenho de Fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
A new two-dimensional (2D) photonic crystal (PC) structure with effective refractive index approaching -1, consisting of periodic array air holes in silicon, is proposed. The light radiated from a point source can form an image through a single wedge PC. Numerical results show that the half-width of the image reaches 0.44λ, which is lower than half of the incident wavelength. In addition, the light through the combination of two of the same PCs can also form subwavelength imaging of which the half-width reaches 0.67λ, and the image almost flipped 180° compared with a point source.