Tailoring synthesis of Ni3S2 nanosheets with high electrochemical performance by electrodeposition

Nickel sulfide nanosheets with high electrochemical performance were successfully synthesized by an electrochemical deposition method. It is interesting to notice that the size, thickness and surface area were simply tailored by adjusting the initial potential during synthesis without changing other reaction conditions. The highest electrochemical performance was achieved on the nickel sulfide sample prepared at initial potential of ?0.9?V. This sample not only presented high specific capacitance at low current density (1958.0F?g^?1 at 3.3?A?g^?1), but also exhibited excellent high rate performance (672.8F?g^?1 at 98.7?A?g^?1). To the best of our knowledge, these values are in the highest level as compared with other works. The high electrochemical performance of nickel sulfide sample originates from its thin thickness.     

NiCo2O4/C复合电极材料的制备以及超级电容性能

采用化学共沉淀法合成了纳米级NiCo2O4/C复合材料,并以X射线衍射(XRD)、扫描电镜(SEM)对样品进行了结构和形貌的表征,结果表明,合成的复合材料为立方尖晶石结构,其粒径大小为30～40nm,颗粒呈球形且分布均匀。循环伏安(CV)、恒电流充放电测试表明,NiCo2O4/C复合材料在6mol/LKOH水系电解液中表现出优异的超级电容特征,在0～0.9V的电位范围内,NiCo2O4/C电极材料比电容量可高达290.49F/g,并具有良好的可逆性和优异的循环性能。     

Flower-like Bi2S3/rGO modified separator for lithium-sulfur batteries

A shuttle effect of polysulfide is one of the crucial barriers for Lithium-sulfur batteries (LSBs). Herein, a flower-like Bi₂S₃/reduced graphene oxide (rGO) modified separator was fabricated by simple solvothermal and filtration processes. Benefiting from the strong chemical capturing ability of flower-like Bi₂S₃ and conductive pathway derived from rGO, the modified separator obviously alleviated the polysulfide shuttling. The cell with the flower-like Bi₂S₃/rGO modified separator exhibits a reversible capacity of 600 mAh g^?1 at 0.5C after 300 cycles and a rate capacity of 500 mAh g^?1 at 2C.     

Investigation of structural and electrochemical properties of Na2Mn2(SO4)3 cathode for sodium-ion batteries

Journal of Materials Science: Materials in Electronics - Electrode materials with the benefits of high working voltage, low cost, and environmental benign are needed for the realization of...     

The synthesis and electrochemical performance of NiCo2O4 embedded carbon nanofibers for high-performance supercapacitors

Construction of transition metal oxides-based carbonaceous nanostructures has been regarded as one of the most effective strategies to prepare the electrodes for high-performance supercapacitors. In this work, NiCo₂O₄ embedded carbon nanofibers (NiCo₂O₄-CNFs) are synthesized by the combination of one-step electrospinning and following thermal treatment. The obtained NiCo₂O₄-CNFs are evaluated as electrodes for supercapacitors. The testing results indicate that the NiCo₂O₄-CNFs present high specific capacitance of 836 F g^?1 (vs. 38.02 F g^?1 for carbon nanofibers (CNFs)) at 5 A g^?1, and outstanding cycling ability with 80.9% retention after 2000 cycle times. Such excellent performances benefit from the integration of electric double layer capacitors and pseudocapacitors. This kind of NiCo₂O₄-embedded carbon nanofibers can serve as a promising candidate for electrode materials for supercapacitors.     

Iron sulfides with dopamine-derived carbon coating as superior performance anodes for sodium-ion batteries

Nano Research - High energy ball-milled iron sulfides with thin carbon layer coating (BM-FeS/C composites) were prepared by the simple and economical process. Ball-milled process, followed by...     

Magnetic mesoporous organic-inorganic NiCo2O4 hybrid nanomaterials for electrochemical immunosensors

This study demonstrates a facile and feasible strategy toward the development of advanced electrochemical immunosensors based on chemically functionalized magnetic mesoporous organic-inorganic hybrid nanomaterials, and the preparation, characterization, and measurement of relevant properties of the immunosensor for detection of carcinoembryonic antigen (CEA, as a model analyte) in clinical immunoassays. The as-prepared nanomaterials composed of a magnetic mesoporous NiCo(2)O(4) nanosheet, an interlayer of Nafion/thionine organic molecules and a nanogold layer show good adsorption properties for the attachment of horseradish peroxidase-labeled secondary anti-CEA antibody (HRP-anti-CEA). With a sandwich-type immunoassay format, the functional bionanomaterials present good analytical properties to facilitate and modulate the way it was integrated onto the electrochemical immunosensors, and allows the detection of CEA at a concentration as low as 0.5 pg/mL. Significantly, the immunosensor could be easily regenerated by only using an external magnet without the need of any dissociated reagents. Importantly, the as-synthesized magnetic mesoporous NiCo(2)O(4) nanomaterials could be further extended for detection of other biomarkers or biocompounds.     

NiCo_2O_4微球的制备及其电化学性能

通过简单的水热法以及后续热处理,成功合成介孔NiCo_2O_4微球。利用FESEM、TEM、XPS和电化学工作站对样品的表面形貌、元素价态和电化学性能进行表征。结果表明:合成的NiCo_2O_4拥有丰富的多孔纳米针状结构,表现出较高的比表面积。由于这种三维多孔纳米结构,当NiCo_2O_4微球作为电极材料时,展现出优异的电容特性,在1A·g-1的电流密度下比电容高达1 554F·g-1,而且当电流密度增加到20A·g-1时,电容保持率为87.5%。另外,在5A·g-1的电流密度下,经过2 000次的充放电循环后,比电容仍能保持初始电容的90.4%。良好的电化学性能表明,NiCo_2O_4微球是一种理想的超级电容器电极材料。     

Improved electrochemical performance of LiCoPO4 nanoparticles for lithium ion batteries

Single phase LiCoPO4 nanoparticles were synthesized by solid-state reaction. LiCoPO4/Li batteries were fabricated in an argon-filled glove box, and their electrochemical properties were analyzed by cyclic voltammetry (CV) and charge-discharge tests. The structural performance of LiCoPO4 nanoparticles was investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD result demonstrated that LiCoPO4 nanoparticles had an orthorhombic olivine-type structure with a space group of Pmnb. The charge-discharge tests indicated that the initial discharge capacity and coulombic efficiency of LiCoPO4/Li batteries were 110 mA h/g and 48% in cut-off voltage range of 3.0-5.3 V, 90 mA h/g and 54% in cut-off voltage range of 3.0-5.1 V, 70 mA h/g and 60% in cut-off voltage range of 3.0-5.0 V, respectively. After 30 cycles, the coulombic efficiency was 78% for 3.0-5.3 V, 88% for 3.0-5.1 V, 91% for 3.0-5.0 V, respectively. These results indicated that the coulombic efficiency of LiCoPO4/Li battery increased upon cycling and upon decreasing in charge upper limit voltage, respectively.     

NiCo2O4/Co3O4纳米材料的球磨法制备及电化学性能

通过高能球磨碳酸镍、碱式碳酸钴的方法制备了NiCo2O4/Co3O4复合材料.系统研究了原料质量比、球磨参数以及退火温度等对材料的微观形貌、结构、组份以及反应活化能和电化学性能的影响.结果表明,在碳酸镍和碱式碳酸钴质量比为2:8,球磨时间为48 h,退火温度为300℃条件下制得复合材料在电位范围0～0.45 V,电流密...     

Enhanced electrochemical performance of graphitic carbon-wrapped spherical FeOF nanoparticles using maleopimaric acid as a cathode material for sodium-ion batteries

Sodium-ion batteries(SIBs)are considered one of the most promising energy storage systems for replac-ing lithium-ion batteries because of the high abundance and low cost of sodium.Iron oxyfluoride(FeOF)is a promising conversion-based cathode material for SIBs because of its high theoretical capacity of about 855 mA h g-1,low-cost chemical compositions,and its lower sensitivity to the size of charged carrier ions.However,the poor electrical conductivity and ionic diffusion of FeOF result in a low rate capability and cyclability.In this work,FeOF nanoparticles wrapped by graphitic carbon layers were synthesized using abietic or maleopimaric acid as both the carbon source and organic ligand.In addition,the mor-phology of the FeOF particles was gradually controlled from rod to spherical shapes,simply depending on the rosin acids.The FeOF nanoparticles prepared with maleopimaric acid showed a large reversible discharge capacity of 356.7 mA h g-1 with a fading rate of 0.21％per cycle after 100 cycles at a current density of 100 mA g-1 and an excellent rate capability.     

Enhanced electrode kinetics and electrochemical properties of low-cost NaFe2PO4(SO4)2 via Ca2+doping as cathode material for sodium-ion batteries

In recent years,sodium-ion batteries(SIBs)have been considered as one of the most promising alterna-tives to lithium-ion batteries(LIBs).Here,a new Na-super-ionic conductor(NASICON)cathode material NaFe2PO4(SO4)2 is successfully prepared through solid state method for SIBs.While the poor electronic conductivity of iron-based materials results in its poor rate and cycle performance.Then the electro-chemical is effectively promoting via Ca2+doping.Na0.84Ca0.08Fe2PO4(SO4)2 have achieved considerable electrochemical properties.The first discharge specific capacity is 121.6mAhg-1 at 25mAg-1 with the voltage platform(～3.1 V)corresponding to Fe2+/3+.After 100 cycles,the capacity retention is 55.1％.The excellent electrochemical performance is caused by some Na+is substituted by Ca2+and leading to the fast sodium kinetics,which is well proved by the powder X-ray diffraction pattern and well corresponding to the galvanostatic intermittent titration technique and cyclic voltammetry testing result(the diffusivity values are around at 10-12 cm2 s-1).     

Two-dimensional metallic BP as anode material for lithium-ion and sodium-ion batteries with unprecedented performance

Improving the storage capacities of electrode materials is one of the most critical points for ion batteries. Two-dimensional (2D) topological semimetals with high carrier mobility are naturally suitable as electrode materials. Herein, using the first-principle calculations, 2D BP monolayer with Dirac-type band structure is predicted to be a superior anode material with ultrahigh capacity for both Li/Na-ion batteries. The BP monolayer remains metallic after the adsorption of Li/Na ions, ensuring a good conductivity. Furthermore, BP owns low diffusion barriers (0.35 eV for Li ions and 0.16 eV for Na ions) and a moderate lattice change (3%) during the process of charging and discharging. Remarkably, the storage capacity of monolayer BP is enhanced to 1924 mAh/g by multilayer adsorption of both Li/Na ions, much higher than those of most previous 2D anode materials. All these characteristics strongly suggest that BP has great potential as a superior anode material in Li/Na-ion batteries.

     

FeSe2 clusters with excellent cyclability and rate capability for sodium-ion batteries

Sodium-ion batteries (SIBs) have great promise for sustainable and economical energy-storage applications. Nevertheless, it is a major challenge to develop anode materials with high capacity, high rate capability, and excellent cycling stability for them. In this study, FeSe₂ clusters consisting of nanorods were synthesized by a facile hydrothermal method, and their sodium-storage properties were investigated with different electrolytes. The FeSe₂ clusters delivered high electrochemical performance with an ether-based electrolyte in a voltage range of 0.5–2.9 V. A high discharge capacity of 515 mAh·g^–1 was obtained after 400 cycles at 1 A·g^–1, with a high initial columbic efficiency of 97.4%. Even at an ultrahigh rate of 35 A·g^–1, a specific capacity of 128 mAh·g^–1 was achieved. Using calculations, we revealed that the pseudocapacitance significantly contributed to the sodium-ion storage, especially at high current rates, leading to a high rate capability. The high comprehensive performance of the FeSe₂ clusters makes them a promising anode material for SIBs.

     

MH-Ni电池的电化学性能再生研究

首次采用超声波震荡的方法,利用其特有的"空化效应",使电池在非破坏状态下在一定程度上可达到电池容量再生的目的,部分实现了MH-Ni电池的循环再利用.利用SEM、XRD、EDAX等检测方法对经超声波作用前后的材料形貌及表面元素变化做了进一步的分析与讨论.实验结果表明,MH-Ni电池在一定介质温度下经超声波处理后,正、负极材料活性物质均有较为明显的分散现象,可使负极表面的惰性氧化层分散脱落,露出新鲜表面,增加参加反应的活性中心,改善电极的电催化活性.超声波作用6h后的电池电化学性能的恢复最为明显.     

Organic materials for rechargeable sodium-ion batteries

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