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- 摘要
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- 实验方案
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Advanced Electrode Materials Comprising of Structurea??Engineered Quantum Dots for Higha??Performance Asymmetric Microa??Supercapacitors
摘要： Micro-supercapacitors (MSCs) as a new class of energy storage devices have attracted great attention due to their unique merits. However, the narrow operating voltage, slow frequency response, and relatively low energy density of MSCs are still insufficient. Therefore, an effective strategy to improve their electrochemical performance by innovating upon the design from various aspects remains a huge challenge. Here, surface and structural engineering by downsizing to quantum dot scale, doping heteroatoms, creating more structural defects, and introducing rich functional groups to two dimensional (2D) materials is employed to tailor their physicochemical properties. The resulting nitrogen-doped graphene quantum dots (N-GQDs) and molybdenum disulfide quantum dots (MoS2-QDs) show outstanding electrochemical performance as negative and positive electrode materials, respectively. Importantly, the obtained N-GQDs//MoS2-QDs asymmetric MSCs device exhibits a large operating voltage up to 1.5 V (far exceeding that of most reported MSCs), an ultrafast frequency response (with a short time constant of 0.087 ms), a high energy density of 0.55 mWh cm?3, and long-term cycling stability. This work not only provides a novel concept for the design of MSCs with enhanced performance but also may have broad application in other energy storage and conversion devices based on QDs materials.
关键词： supercapacitors,electrode materials,engineering,molybdenum disulfide quantum dots,nitrogen-doped graphene quantum dots
更新于2025-09-16 10:30:52
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Lithium-Ion Capacitor for Photovoltaic Energy System
摘要： A design of photovoltaic energy system consisting of a solar panel and hybrid supercapacitor is discussed. The application of lithium-ion capacitor in photovoltaic energy system is considered to be a novel promising way in order to fill up the gap between the specific energy, power and service life of the battery and supercapacitor. In this work there was developed an advanced lithium-ion capacitor that can provide both a sufficiently high energy density and the increased power density and service life. Developing the lithium-ion capacitors, the capacity of cathode can vary over a wide range, reaching the value required for the optimum photovoltaic energy system performance.
关键词： photovoltaic energy systems,supercapacitors,batteries,lithium-ion capacitors,hybrid electrochemical capacitors
更新于2025-09-16 10:30:52
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In Situ Monitoring Small Energy Storage Change of Electrochromic Supercapacitors via Perovskite Photodetectors
摘要： In situ monitoring the healthy state of energy storage devices is a smart way to avoid severe accidents and major emergencies. Electrochromic supercapacitors (ECSCs) stand out among other devices owing to the smart color variation during charge and discharge processes. However, it is hard to obtain the precise state of charge via only identifying their color change. To address this problem, an integral system composed of the inorganic CsPbBr3 perovskite photodetector (PPD) and polyaniline (PANI)//WO3 ECSC is proposed here. The PPD can simultaneously collect the variation of responsive current (under a green laser with the wavelength of 520 nm) when the ECSC is being charged or discharged. The real-time state of charge following the color change can be recorded by the PPDs constantly and accurately. A voltage alteration as small as 47.2 mV (charge variation of 0.33 mC) can be detected by this integral system rapidly, implying its great potential in managing the health condition of ECSC or even common energy storage devices in the future.
关键词： in situ monitors,small energy storage change,perovskite photodetectors,supercapacitors,electrochromic
更新于2025-09-12 10:27:22
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Voids in walls of mesoporous TiO2 anatase nanotubes by controlled formation and annihilation of protonated titanium vacancies
摘要： Amorphous TiO2 nanotubes (TNTs) grown anodically on Ti metal in aqueous electrolytes show a crystallization behaviour strongly dependent on the atmosphere used during annealing at high temperature. In wet oxidizing conditions, the amorphous TNTs walls transform into relatively large and well crystallized anatase-like domains permeated by prismatic voids. On the other hand, crystallization of the amorphous nanotubes under dry reducing conditions induces nanocrystalline aggregates that do not show prismatic voids and exhibit different electronic properties. Supported by density functional theory calculations, it is argued that the formation or absence of voids can be understood in terms of formation and condensation of protonated titanium vacancies. Tunable morphology through defect chemical engineering as such, enables TNTs with increased surface area and catalytic activity, which find potential application in supercapacitors, sensors, photocatalysis, photoelectrochemistry, and dye-sensitized solar cells.
关键词： TiO2 nanotube voids,Titanium oxohydroxide,Supercapacitors,Black titania,Anatase
更新于2025-09-12 10:27:22
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Simultaneous densification and nitrogen doping of laser-induced graphene by duplicated pyrolysis for supercapacitor applications
摘要： Laser pyrolysis of polyimide is a facile and cost-effective method to fabricate high performance supercapacitor electrodes. This study proposes a duplicated laser pyrolysis method to densify pyrolyzed carbon electrodes and hence improve electrochemical performance. The initial laser pyrolysis of polyimide generates a graphene-like carbon, called laser-induced graphene (LIG). This LIG is then coated with an additional polyimide layer, and the second laser pyrolysis is applied, producing densified LIG. Laser power effects on densified LIG morphology and electrochemical characteristics are investigated, confirming remarkable density increase. Increased nitrogen content is also observed, signifying significant nitrogen doping. The densified electrode achieves 49.0 mF cm?2 specific capacitance at 0.2 mA cm?2 current density in a standard three-electrode system, approximately 6-fold that for singly pyrolyzed LIG electrodes. A solid-state flexible supercapacitor with densified LIG electrodes is fabricated using a gel electrolyte (PVA-H2SO4), achieving 19.8 mF cm?2 capacitance at 0.05 mA cm?2 current density, with outstanding cyclic charge-discharge stability and mechanical flexibility.
关键词： Nitrogen-doped carbon,Laser pyrolysis,Densification,Laser-induced graphene,Flexible supercapacitors
更新于2025-09-11 14:15:04
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Manganese oxide nanofoam prepared by pulsed laser deposition for high performance supercapacitor electrodes
摘要： Manganese oxide nanofoam has been prepared by pulsed laser deposition, from a metallic Mn target in a 5 Torr pressure O2 buffer atmosphere. The as-prepared samples were heat-treated at different temperatures (300?C-500?C) in air. Both as-deposited and heat-treated samples have a high porosity foam-like morphology, as shown by Field Emission Scanning Electron Microscopy. High Resolution Transmission Electron Microscopy revealed that the nanofoam is composed by linked nanoparticles with slight crystallization and growth of the nanoparticles due to heat-treatment, which was confirmed by X-ray diffraction, Raman Spectroscopy and X-ray Photoelectron Spectroscopy. These techniques also showed a variable oxide composition upon heat treatment. The supercapacitive properties of manganese oxide nanofoam treated at 300?C exhibited a specific capacitance higher than 1000 F/g, in the 0 to +1.0 V potential range. After heat treatment at 400?C and 500?C, the specific capacitance decreased compared to that of the 300?C treated sample. An increase of about 130% in the initial capacitance was obtained after 500 cycles for this sample. However, it decreases to one third of the maximum value after 5000 cycles. The results shows that the obtained manganese oxide nanofoam has very high specific capacitance but need to improve the cycle stability.
关键词： microstructures,pulsed laser deposition,porous materials,supercapacitors,nanofoam,manganese oxides
更新于2025-09-11 14:15:04
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Ca <sub/>3</sub> La <sub/>2</sub> Te <sub/>2</sub> O <sub/>12</sub> :Mn <sup>4+</sup> ,Nd <sup>3+</sup> ,Yb <sup>3+</sup> : an efficient thermally-stable UV/visible–far red/NIR broadband spectral converter for c-Si solar cells and plant-growth LEDs
摘要： Highly conductive PEDOT:PSS threaded HKUST-1 thin films with high porosity were prepared. The highest conductivity of these films was 13 S cm?1, nine orders of magnitude greater than that of pristine HKUST-1. A PEDOT:PSS threaded HKUST-1 thin film with 20 wt% PEDOT:PSS exhibits 300 times enhancement of the electrochemical performance of pristine HKUST-1 when applied as an electrode for thin-film-like supercapacitors.
关键词： thin films,HKUST-1,conductivity,supercapacitors,PEDOT:PSS
更新于2025-09-11 14:15:04
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Flakes Size-Dependent Optical and Electrochemical Properties of MoS2
摘要： Background: Molybdenum disulfide (MoS2) is a transition metal dichalcogenides and has some interesting and promising properties. MoS2 has direct and indirect band gaps depending on its crystalline structure. In addition, its sheets morphology makes it a good candidate for supercapacitor applications. Objective: The aim of this work is to study the effect of MoS2 flakes size on its optical and electrochemical properties. Method: MoS2 with different flakes sizes were prepared by exfoliation method. The exfoliation was performed by sonication of MoS2 powder in N,N-Dimethylformamide followed by different centrifugation speeds. UV-Vis spectra illustrated the optical energy gap was inversely proportional to the MoS2 flakes size. Results: Absorption coefficient values indicated that the exfoliation reduced the number of layers. Symmetric supercapacitor was made from two MoS2 electrodes and tested in 6 M KOH electrolyte. The specific capacitance was found to be dramatically increased with decreasing flakes size (9.5 and 4.5 mF/cm2 for 0.26 and 0.98 μm flakes size, respectively). Conclusion: These findings recommend that MoS2 can be the excellent electrode material for supercapacitor.
关键词： nanoflakes,cyclic voltammetry,supercapacitors,Transition Metal Dichalcogenides (TMDs),optical band gap,Molybdenum disulfide
更新于2025-09-10 09:29:36
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[Nanostructure Science and Technology] Nanowire Electronics || X-Ray Spectroscopic Analysis of Electronic Properties of One-Dimensional Nanostructured Materials
摘要： Recent studies of the control of the shape and size of nanomaterials have enabled researchers to explore the development of energy storage and conversion applications in unprecedented detail. Nanomaterials can be exploited into green energy strategies if their surface architectures can be controlled by various treatment processes. Their remarkable behaviors arise in part from their small size, large surface area, and quantum con?nement. Nanomaterial science has various implications for environmental science and sustainability. Physical and chemical routes for controlling morphologies, crystal structures, and physical and chemical properties can be exploited to improve performance, expand the function, and extend lifetime of devices with energy storage and conversion applications. Such devices that involve nanomaterials include storage and conversion devices (energy storage, hydrogen generation, water-splitting and dye-sensitized solar cells (DSSC)), optical and electronic devices (semiconductors, photoelectrocatalytic, and waveguides), and environmental devices (sensors and adsorption/separation), among others. Such applications typically rely on emerging electrode designs, which support the realization of energy storage and conversion devices, whose manufacture can be done more ef?ciently by nanotechnology. The unique features of nanomaterials have been in the development of energy storage and conversion proved to be useful.
关键词： supercapacitors,nanomaterials,conversion,water-splitting,X-ray absorption spectroscopy,energy storage,MnO2,TiO2
更新于2025-09-10 09:29:36
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Printable Fabrication of a Fully Integrated and Self-Powered Sensor System on Plastic Substrates
摘要： Wearable and portable devices with desirable flexibility, operational safety, and long cruising time, are in urgent demand for applications in wireless communications, multifunctional entertainments, personal healthcare monitoring, etc. Herein, a monolithically integrated self-powered smart sensor system with printed interconnects, printed gas sensor for ethanol and acetone detection, and printable supercapacitors and embedded solar cells as energy sources, is successfully demonstrated in a wearable wristband fashion by utilizing inkjet printing as a proof-of-concept. In such a “wearable wristband”, the harvested solar energy can either directly drive the sensor and power up a light-emitting diode as a warning signal, or can be stored in the supercapacitors in a standby mode, and the energy released from supercapacitors can compensate the intermittency of light illumination. To the best of our knowledge, the demonstration of such a self-powered sensor system integrated onto a single piece of flexible substrate in a printable and additive manner has not previously been reported. Particularly, the printable supercapacitors deliver an areal capacitance of 12.9 mF cm?2 and the printed SnO2 gas sensor shows remarkable detection sensitivity under room temperature. The printable strategies for device fabrication and system integration developed here show great potency for scalable and facile fabrication of a variety of wearable devices.
关键词： wearable and flexible devices,printable supercapacitors,printable gas sensors,monolithically integrated self-powered systems,inkjet printing
更新于2025-09-09 09:28:46