Energy technology最新文献

The development of low-cost, high-performance electrocatalysts for the oxygen evolution reaction (OER) is essential for a vast array of chemical and energy transformation applications. Using non-platinum metals as electrocatalysts in a key process such as OER has become increasingly attractive given their relatively low cost, high electrocatalytic activity, and low environmental impact. Herein, to achieve a better catalytic material with high permeability and mass charge transfer in a catalytic framework, a novel, oxygen-defective Sm₂O₃/CuO nanohybrid with nanocuboid architecture is developed. The creation of a new composite material which consist of samarium oxide and copper oxide, demonstrates high effectiveness in the process of electrochemical water splitting. The combined use of samarium oxide and copper oxide improves the electrocatalytic performance, stability, and durability due to it synergistic effect. In alkaline media, the Sm₂O₃/CuO nanocomposite exhibits an astonishing overpotential of 248 mV along with a lower Tafel value of 46 mVdec⁻¹ for OER and nanocomposite also exhibits acceptable hydrogen evolution reaction (HER) performance. Due to the unprecedented porous nanocuboid morphology and the strong synergistic effect between the two materials, the oxygen-defective Sm₂O₃/CuO composite exhibits impressive electrical properties and performs exceptionally well as an electrocatalyst for intrinsic water splitting. At an operational potential of 0.5 V, porous Sm₂O₃/CuO displays outstanding reactivity, Sm₂O₃/CuO exhibits remarkable results during electrochemical operation.

Defect-type carbon, doped with nitrogen and oxygen, is synthesized using the high-temperature solid-phase method. X-ray photoelectron spectroscopy analysis reveals the presence of nitrogen, including pyridine nitrogen, pyrrole nitrogen, and graphitized nitrogen, incorporated into the carbon structure. Additionally, oxygen is introduced into carbon, with both CO and CO functionalities are observed. Transmission electron microscopy and scanning electron microscopy indicate that all samples exhibit a morphology of carbon microblocks with localized turbocharged lattice regions. Electrochemical tests demonstrate that the nitrogen- and oxygen-doped carbon microblocks exhibit excellent cycling performance and high rate capacity. Specifically, at current densities of 1 and 2 A g⁻¹, the rate capacity remains at 385.6 and 214.4 mA h g⁻¹, respectively. Furthermore, the discharge capacity at 5 A g⁻¹ remains at 58.3 mA h g⁻¹ on the 3500th cycle. The defects introduced by nitrogen and oxygen doping not only enhance reactivity and electronic conductivity but also improve lithium-ion diffusion dynamics.

The properties of lithium-ion battery (LIB) anodes fabricated from nanoscale silicon Si and polyaniline (PANI) as a binder are reported. PANI is prepared by in situ polymerization of aniline in the presence of phytic acid, which serves both as dopant and as a gel-forming agent. PANI pellets obtained by dry compression are used to investigate the morphology and to measure the resistivity of PANI and Si/PANI composites. The anodes are fabricated using the slurry technique. Their properties as a function of precursor ratio are studied in the half-cell cells by charge–discharge characteristics, cyclic voltammetry, electrochemical impedance spectroscopy and cyclic lifetime. It is shown that stable cycling (>350 cycles at a current of 300 mA g⁻¹) is inherent only to thin Si/PANI layers with composite loading <0.7 mg cm⁻². The discharge capacity in this case is as high as 500–800 mAh g⁻¹.

Safety monitoring sensors in smart railways need a sustainable onboard power supply. This article proposes a counter-rotating gear energy harvester (CG-EH) to convert the longitudinal vibration energy of trains into electricity for onboard sensors.CG-EH consists of a vibration input module, a motion conversion module, and an energy conversion module. The vibration input module converts the longitudinal displacement of the coupler into the rotational motion of the gears. The motion conversion module realizes the conversion of the reciprocating input displacement into the unidirectional rotation based on a counter-rotating gear set, multi-stage spur gear sets can effectively mitigate the effects of excitation on CG-EH. The energy conversion module transforms the kinetic energy of the unidirectional rotation into electrical energy through a generator. Experimental results show that the energy outputs of CG-EH are improved with longitudinal vibration compared with the usual onboard energy harvester. From the result, the peak output power of CG-EH is 14.59 W, the peak efficiency reaches 39.2%, enough to power relevant onboard sensors. Moreover, CG-EH can monitor the running status of trains based on deep learning. From the experiment results and application prospects, CG-EH is a favorable solution for the power supply problems of onboard sensors in smart railways.

This study assesses the mechanical, thermal, and dielectric properties, as well as the conductivity and water contact angle, of eco-friendly polyethylene oxide (PEO) and aluminium oxyhydroxide (AlOOH) films prepared using water as a green solvent for fabricating flexible nanodielectric devices. X-ray diffraction and Fourier transform infrared analysis confirm the presence of AlOOH in the nanocomposites. Field emission scanning electron microscopy analysis reveals the surface morphology of nanocomposites, showing a more uniform distribution of AlOOH nanoparticles at 5 and 7 wt% loading. The influence of nanofiller content on the thermal properties of films is evaluated by differential scanning calorimetry and thermogravimetric analysis. Increasing AlOOH content significantly enhances both the glass transition temperature and the thermal stability of PEO/AlOOH nanocomposites. The films exhibit improved mechanical properties, with a tensile strength of 31.11 MPa and Young's modulus of 339 MPa at 5 wt% AlOOH. Electrical conductivity, dielectric parameters, and complex impedance are measured for all films. The PEO with 7 wt% AlOOH shows optimal electrical conductivity and dielectric constant. These findings suggest that altering AlOOH concentrations enables fine-tuning of the thermal, mechanical, and electrical properties of nanocomposite films. This versatility offers great potential for developing advanced flexible organoelectronic devices and nanodielectric materials.

Owing to iron's natural abundance, low cost, and affordability, nonaqueous rechargeable iron-ion (Fe-ion) batteries have the potential for alternative rechargeable energy-storage devices. However, developing cathodes with adequate superior Fe²⁺ storage during charge–discharge is a major challenge. Herein, V₂O₅ porous microspheres (V₂O₅–PMS) are synthesized as efficient cathodes due to their unique characteristics, including high surface area and large interlayer spacing, which provide high electrochemical performance and fast charge kinetics. The nonaqueous Fe-ion battery is fabricated under ambient conditions using mild steel as an anode and a V₂O₅–PMS cathode. The cyclic voltammetry measurements suggests a high diffusion coefficient of Fe²⁺ ions in the redox process during charge–discharge. The V₂O₅–PMS-based cathode shows ≈205 mAh g⁻¹ gravimetric capacity at 33 and ≈70 mAh g⁻¹ at 1 A g⁻¹ (≈15 C). It exhibits capacity retention of ≈70% in 600 cycles at a very high current rate of 3 A g⁻¹. The impedance spectroscopy measurements are carried out between the cell's cycling to understand the electrode–electrolyte interface resistance over cycling. The four CR-2032 coin cells are assembled in series to glow a white and red light-emitting diode to demonstrate its potential as an alternative energy-storage system.

Li–Se batteries are promising energy storage systems due to the high theoretical volumetric capacity and electrical conductivity of selenium. However, the formation of dissolved polyselenide in ether-based electrolytes is one of the main factors affecting the electrochemical performance of Li–Se batteries. Herein, the presence and solubility of polyselenides in ether-based electrolytes are initially investigated using UV–vis spectroscopy and compared with carbonate-based solvents. Then, to address the polyselenide shuttle effect, SnCl₂-containing poly(acrylonitrile-co-vinylpyrrolidone) (oPANVP/SnCl₂) nanofibrous interlayer is utilized to retain the dissolved compounds. The absorption capacity of this interlayer is investigated and quantitatively demonstrated by UV–vis spectroscopy. The cell with the interlayer achieves a discharge capacity of 266 mAh g⁻¹ after 150 cycles, significantly higher than the cell without the interlayer. Furthermore, 3-electrode electrochemical impedance spectroscopy and open-circuit voltage monitoring are conducted to investigate the impact of the oPANVP/SnCl₂ interlayer on the solubility of polyselenides. The improved electrochemical results indicate that ether-based electrolytes can be successfully utilized in Li–Se batteries when an effective interlayer is present to adsorb polyselenides.

This study introduces a novel approach through the design and creation of a composite electrode, uniquely made of three distinct layers of micro/mesoporous electrospun carbon nanofiber (CNF) mats, featuring a gradient in pore size. This innovative gradient pore structure merges the benefits of varying pore sizes, significantly enhancing redox flow battery (RFB) efficiency. The first layer, a microporous CNF mat situated near the membrane, offers an extensive reactive surface area, minimizing charge transfer resistance and speeding up electrochemical reactions—key factors in enhancing battery reaction efficiency. The next layer, a mesoporous CNF mat, fine-tunes the flow properties of the electrolyte, lowering flow resistance while ensuring superior charge transfer capabilities. This structured gradient in pore size not only facilitates improved electrolyte penetration and even distribution but also harmonizes the balance between charge transfer efficiency and electrolyte flow, thus mitigating energy losses without compromising reaction velocity. Charge–discharge testing demonstrated notable performance gains: an energy efficiency of 82% at 100 mA cm⁻² (surpassing traditional electrodes by 71.5%) and 69% at 200 mA cm⁻², alongside a 77.4% increase in peak power density. This advancement not only enhances energy and power densities but also its lifespan, marking a significant step forward for RFB technologies.