Sodium-ion battery has emerged as one of most promising technologies for large-scale energy storage system, and hence has stimulated extensive exploration of applicable electrode materials with low ...cost and superb electrochemical properties. Herein, 3D graphene decorated Na4Fe3(PO4)2(P2O7) microspheres as a low-cost and environmentally friendly cathode material are synthesized by using a facile spray-drying method. The as-prepared NFPP@rGO composite exhibits a high reversible capacity of 128 mAh g−1 at 0.1 C, a superior rate capability (35 mAh g−1 at 200 C), and a long cycling life (62.3% capacity retention over 6000 cycles at 10 C). The excellent electrochemical performance is attributed to combined advantages of graphene coating on the surface of nanoparticles and the flexible 3D graphene network, which not only improve the electronic conductivity, but also accommodate the structural stress of the material during charging and discharging. Therefore, the NFPP@rGO microsphere with superior electrochemical performances, low-cost raw materials, simple synthetic route and high thermal stability is considered as a very attractive cathode electrode for sodium ion battery.
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•NFPP@rGO microsphere is synthesized by using a facile spray-drying method.•The NFPP@rGO composite exhibits high electrochemical performance for Na ion storage.•The excellent performance is attributed to combined advantages of graphene coating and 3D network.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•ZIF-8 was used as a multifunctional gatekeeper for HMSN-BTA.•HMSN-BTA@ZIF-8 was well-dispersed in epoxy matrix.•HMSN-BTA@ZIF-8 notably improved anticorrosion performance for epoxy ...coating.•HMSN-BTA@ZIF-8/epoxy coatings exhibited excellent self-healing performance.
Zeolitic imidazole framework-8 (ZIF-8) with porous structure, pH-response and facile synthesis characteristics, as a molecule delivery and stimulus-response nanomaterial, has been widely investigated over the past decades. Here, we report for the first time a new corrosion inhibitor-encapsulated nanocontainer (denoted as HMSN-BTA@ZIF-8), successfully synthesized using ZIF-8 as self-sacrificial template, pH-responsive gatekeeper and interfacial compatibility assistant for hollow mesoporous silica nanoparticle (HMSN). Corrosion inhibitors of benzotriazole (BTA) are encapsulated in the cavity and mesopores of HMSN. The results demonstrate that there are outstanding pH-triggered activities to both acidic and alkaline conditions for HMSN-BTA@ZIF-8. Rather than physically dispersing nanocontainers in the coating matrix, the synthesized HMSN-BTA@ZIF-8 can covalently interact with epoxy resin, resulting in superior compatibility and more uniform dispersion behavior of nanocontainers in the coatings. Interestingly, the epoxy composite coating with HMSN-BTA@ZIF-8 exhibits excellent corrosion protection and outstanding self-healing performances, which are well characterized by potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), salt spray test and Scanning Kelvin Probe (SKP) technique. The outstanding anticorrosion and impressive self-healing properties are attributed to the good compatibility of HMSN-BTA@ZIF-8, the hydrophobicity of ZIF-8, higher crosslinking densities, and the controllable release of BTA in the epoxy composite coating. It is believed that this work is very helpful for extending the service life of various anticorrosion coatings.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Batteries and electrochemical capacitors play very important roles in the portable electronic devices and electric vehicles and have shown promising potential for large-scale energy storage ...applications. However, batteries or capacitors alone cannot meet the energy and power density requirements because rechargeable batteries have a poor power property, whereas supercapacitors offer limited capacity. Here, a novel symmetric sodium-ion capacitor (NIC) is developed based on low-cost Na0.44MnO2 nanorods. The Na0.44MnO2 with unique nanoarchitectures and iso-oriented feature offers shortened diffusion path lengths for both electronic and Na+ transport and reduces the stress associated with Na+ insertion and extraction. Benefiting from these merits, the symmetric device achieves a high power density of 2432.7 W kg–1, an improved energy density of 27.9 Wh kg–1, and a capacitance retention of 85.2% over 5000 cycles. Particularly, the symmetric NIC based on Na0.44MnO2 permits repeatedly reverse-polarity characteristics, thus simplifying energy management system and greatly enhancing the safety under abuse condition. This cost-effective, high-safety, and high-performance symmetric NIC can balance the energy and power density between batteries and capacitors and serve as an electric power source for future low-maintenance large-scale energy storage systems.
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Na4Fe3(PO4)2(P2O7) (NFPP), as a typical cathode material of sodium ion battery, has great application prospect because of its low-cost, non-toxicity and appropriate working voltage and theoretical ...capacity. However, its poor electron and ion conductivities associated by non-erasable NaFePO4 impurity generated in all the synthesis methods limits the capacity utilization of NFPP. Herein, we report a novel pure-phase Na4Fe2.91(PO4)2(P2O7) cathode material prepared simply by introducing a small amount of Fe defects in the lattice. The first-principles calculations reveal that Fe defects in the NFPP materials result in a lower band gap and migration energy barriers, thereby leading to a higher electron and Na+ ion conductivity. As a result, the pure-phase Na4Fe2.91(PO4)2(P2O7) cathode exhibits a high discharge capacity (110.9 mA h g−1 at 0.2 C), excellent rate performance (~52 mA h g−1 at 100 C) and outstanding long cycle stability over 10,000 cycles without discernible capacity decay. The pouch cell assembled with Na4Fe2.91(PO4)2(P2O7) cathode and hard carbon anode, shows high capacity retention rate of 87.4% over 1000 cycles. These results suggest a feasible application of the simple defect regulation strategy to synthesize high-quality and pure-phase Na4Fe2.91(PO4)2(P2O7) materials for low-cost sodium-ion batteries.
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A novel and pure phase Na4Fe2.91(PO4)2P2O7, for the first time, prepared by regulating Fe defects, which exhibits extraordinary structural stability and outstanding electrochemical performance for SIBs.
•A novel pure phase Na4Fe2.91(PO4)2(P2O7) is prepared by introducing Fe defects.•The Na4Fe2.91(PO4)2(P2O7) exhibits high Na-storage performance.•The excellent performance is attributed to Fe defects and pure phase.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A rechargeable aqueous Zn/Mn battery is a promising device for large-scale energy storage because of its abundant resources, low cost, and high safety. However, its application is plagued by a poor ...life cycle because of the electrochemical instability of MnO2 in aqueous electrolytes. Here, an alkaline Zn–Na0.44MnO2 dual-ion battery (denoted AZMDIB) is developed for the first time using Na0.44MnO2 as the cathode, a zinc metal sheet as the anode, and a 6 M NaOH aqueous solution as the electrolyte. When the discharge cutoff voltage is lowered to 0.3 V (vs Zn/Zn2+), the Na0.44MnO2 cathode delivers a high capacity of 345.5 mA h g–1 but with a poor cycling performance. The charge–discharge mechanism and structural evolution of the Na0.44MnO2 cathode in an extended potential window (1.95–0.3 V) are also explored. The Na0.44MnO2 electrode experiences two different electrochemical processes: Na+ ions insert/extract reversibly in the potential range of 1.95–1.1 V, and a phase transition occurs from Na0.559MnO2 to Mn(OH)2 below 1.1 V. The latter irreversible reaction is probably due to proton insertion, leading to a severe capacity fade. Nevertheless, in a narrower voltage range (2.0–1.1 V), the AZMDIB full cell exhibits a high reversible capacity (80.2 mA h g–1 at 0.5 C), high rate capability (32 mA h g–1 at 50 C), and excellent cycling stability (73% capacity retention over 1000 cycles at 10 C). Benefiting from the merits of environmental friendliness, cost-effectiveness, and high electrochemical performance, the rechargeable AZMDIB is a promising contender for grid-scale energy storage applications.
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•A new anti-bacterial and anti-corrosion agent was synthesized.•Multifunctional Li-Al layered double hydroxides (LDHs) films on aluminum alloy was prepared by a facile ...method.•Significant enhanced corrosion protection property and excellent hydrophobicity property with the discussion of surface roughness.•Excellent anti-bacterial property against Escherichia coli (gram-negative), Bacillus subtilis (gram-positive) and sulfate-reducing bacteria (anaerobic).
In this work, lithium (Li)-aluminum (Al) layered double hydroxide (LDH) films modified by 4-amino-2-((hydrazine methylene) amino)-4-oxobutanoic acid (denoted as AOA acid) and/or 1H,1H,2H,2H-perfluorooctyltriethoxysilane were prepared on 6N01 Al alloy by a facile, in-situ growth method with enhanced hydrophobicity, anti-biofouling and anti-corrosion performance. The preparation is low energy consumptive and environment friendly, relying on self-assembly at ambient temperature. The structure, molecular weight and functional groups of the synthesized AOA acid were characterized by NMR spectrometer, ESI-MS spectrometer and Fourier transform infrared (FT-IR) spectroscopy. And the compositions, structure and morphology of the films were characterized by Fourier transform infrared (FT-IR) spectroscopy, glancing-angle X-ray diffraction (GA-XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and energy-dispersive x-ray spectrum (EDS). Water contact angle measurements (CA) and atomic force microscopy (AFM) characterization show that the films possess a micro/nanostructure with an improved hydrophobicity. Immersion test, neutral salt tests (NSS) and electrochemical impedance spectroscopy (EIS) conducted in 3.5 wt.% NaCl solutions demonstrate the improved corrosion resistance of the films over bare Al alloy. Meanwhile, the films also possess an excellent anti-bacterial property to Escherichia coli, Bacillus subtilis and sulfate-reducing bacteria.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A facile, environmentally-friendly and low-cost method for one-step synthesis of zinc phthalocyanine (ZnPc) and cobalt phthalocyanine (CoPc) prism-shaped crystals was proposed. The well-defined ...crystalline prisms (ZnPc, up to 8 mm and CoPc, more than 1 mm) can be grown during a solvothermal process at 160 °C for 6 h. It is noted that ethanol (pentanol or benzyl alcohol) was used as the reaction medium and no surfactants or other chemical additives were used in this preparation. To the best of our knowledge, this is the first report on the green and direct synthesis from simple raw materials to large ZnPc and CoPc crystals with high quality. Compared to the traditional preparation of MPc solids and their re-crystallization purification by using H 2 SO 4 , our method is very convenient, safe and time-efficient. The complete characterization, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), single crystal X-ray diffraction, powder X-ray diffraction, and Fourier transform infrared (FT-IR) and Raman spectrometry, was performed to measure the molecular structures, crystal structures, and surface morphologies. The highly predominant crystal face of ZnPc crystals was determined to be (100) and the probable crystal growth mechanism was proposed. Moreover, the thermal and photoelectric measurements of ZnPc and CoPc crystals show their excellent thermal stability and photoelectric transformation performance, respectively.
The limitations of conventional organic liquid electrolytes such as sodium dendrite growth, serious side reactions, and liquid leakage hinder the development of sodium–metal batteries (SMBs). In this ...work, a novel sodium–poly(tartaric acid)borate (NaPTAB) salt with low cost and environmental friendliness was synthesized by an aqueous phase synthesis method. NaPTAB was combined with poly(vinylidene fluoride)–hexafluoropropylene (PVDF–HFP) to form NaPTAB-SM, and then NaPTAB-SM was swelled in the PC solution to obtain a single sodium-ion conductor gel polymer electrolyte (GPE), denoted NaPTAB-SGPE. NaPTAB-SGPE has perfect thermal stability with an initial decomposition temperature of 345 °C, a satisfactory ionic conductivity of up to 0.94 × 10–4 S·cm–1 at room temperature, a wide electrochemical window as high as 5.2 V (vs Na+/Na) at 30 °C, and a high sodium-ion transference number of 0.91 at 60 °C. Except for these satisfying performances, the Na3V2(PO4)3/Na cells assembled with NaPTAB-SGPE present excellent charge–discharge performance and stable cycling capability at high temperatures (60 °C). They also exhibit superior cycling stability compared to the liquid electrolyte cells with 1 M NaClO4 (EC/PC, 1:1, v/v, and 5% fluoroethylene carbonate (FEC)). After cycling, NaF is generated on the polymer electrolyte membrane as observed by 23Na and 19F solid-state NMR, which is more likely responsible for the excellent charge–discharge stability and cycling performance of the battery. These results show that NaPTAB-SGPE is a great potential alternative for solid-state sodium batteries.
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Batteries and electrochemical capacitors play very important roles in the portable electronic devices and electric vehicles and have shown promising potential for large-scale energy storage ...applications. However, batteries or capacitors alone cannot meet the energy and power density requirements because rechargeable batteries have a poor power property, whereas supercapacitors offer limited capacity. Here, a novel symmetric sodium-ion capacitor (NIC) is developed based on low-cost Na
MnO
nanorods. The Na
MnO
with unique nanoarchitectures and iso-oriented feature offers shortened diffusion path lengths for both electronic and Na
transport and reduces the stress associated with Na
insertion and extraction. Benefiting from these merits, the symmetric device achieves a high power density of 2432.7 W kg
, an improved energy density of 27.9 Wh kg
, and a capacitance retention of 85.2% over 5000 cycles. Particularly, the symmetric NIC based on Na
MnO
permits repeatedly reverse-polarity characteristics, thus simplifying energy management system and greatly enhancing the safety under abuse condition. This cost-effective, high-safety, and high-performance symmetric NIC can balance the energy and power density between batteries and capacitors and serve as an electric power source for future low-maintenance large-scale energy storage systems.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
