Energy technology最新文献

In order to explore efficient oxygen carriers (OCs) for chemical looping combustion (CLC), this article investigates Bayan Obo iron concentrate-based Cu-Fe composite OCs with varying Cu/Fe mass ratios (1:1, 1:1.5, 1:2) for CLC performance using thermogravimetric analysis (temperature-programmed reduction (TPR), isothermal reduction, redox cycling) and characterization (Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM)). The TPR tests reveal a three-stage reduction pathway of CuFe₂O₄ with CO: CuFe₂O₄ → Cu + Fe₃O₄ → FeO → Fe. The 1:1 Cu/Fe ratio OCs exhibit good reducibility, with a 4.32% higher mass loss than raw iron concentrate, lower mass-loss commencing temperature than other ratios (280°C), higher oxygen release than other ratios above 806°C under N₂, which intensifies with temperature, and high kinetic activity (always the first to reach equilibrium in isothermal reduction test). In 11 thermogravimetric redox cycles, the 1:1 Cu/Fe ratio sample maintains high reduction conversion, showing a maximum mass loss difference of 5.09% compared to the iron concentrate. Its stable mass loss over the initial seven cycles demonstrates its good cycling stability.

The cover image is based on the article Electrochemical Properties for Hydrogen Production of Nitrogen-Doped Sponge-Like Carbon Nanotubes as High-Surface Area Catalyst by IPICYT López-Urías et al., https://doi.org/10.1002/ente.202500964.

Molten salt thermocline storage systems provide significant cost advantages for concentrated solar power, although their thermal performance is constrained by internal thermal resistance within solid fillers. This study establishes a coupled model integrating solid heat conduction and molten salt convection to analyze thermal resistance between molten salt and solid interfaces. System optimization evaluates key parameters including solid thermal conductivity, filler diameter, molten salt thermal conductivity, and inlet velocity. Results indicate that solid thermal resistance impedes solid-salt heat transfer, with optimal solid thermal conductivity maximizing discharging efficiency. As filler diameter increases from 0.025 to 0.045 m, the optimal solid thermal conductivity rises by 3 W (m K)⁻¹, while the discharging efficiency decreases ≈1.8%. At the optimal solid thermal conductivity, moderate reduction of molten salt thermal conductivity increases discharging efficiency by 3.46%. Reduced inlet velocity further diminishes efficiency, requiring elevated molten salt thermal conductivity to enhance thermal performance at lower flow rates. These findings demonstrate that synergistic optimization of solid thermal conductivity and molten salt thermal conductivity under variable operating conditions can significantly enhance thermocline storage efficiency.

Perovskite solar cells (PSCs) have rapidly advanced in photovoltaic research, achieving power conversion efficiencies up to 27%. However, the toxicity of lead (Pb) and the inherent instability of these materials hinder their commercial adoption. To address these issues, Pb-free perovskites such as layered (2-dimensional) cesium antimony iodide (Cs₃Sb₂I₉) have been investigated for their environmental compatibility and promising optoelectronic properties. However, their efficiencies remain lower than those of Pb-based analogs, and stability is still a challenge. A significant contributor to device instability is the use of doped hole-transport materials, where hygroscopic dopant salts promote moisture ingress and accelerate degradation. Herein, we examine the influence of dopant-free hole transport materials, P3HT, PTB7, and CuSCN, on the performance and stability of layered Cs₃Sb₂I₉ PSCs. Planar devices incorporating PTB7 and CuSCN achieved power conversion efficiencies (PCEs) of 2.05% and 2.26%, respectively, while P3HT yielded the highest PCE of 2.44%, ranking among the best efficiencies reported for this type of solar cell. These findings highlight the potential of dopant-free HTMs to enhance both efficiency and stability in lead-free PSCs.

The implementation of the jet impingement technique in air-cooled building-integrated photovoltaic-thermal (BIPV/T) systems is a promising yet underexplored solution. To assess its potential, a multivariant numerical study of various geometries was carried out. The parameters were derived from an innovative integration of the BIPV/T system with an air-source heat pump. Steady-state computational fluid dynamics (CFD) simulations employed the discrete ordinate radiation and shear stress transport k–ω turbulence models. Systems with different nozzle heights and perforated jet plate positions were compared to a straight-channel reference. Both nozzle-based and perforated jet plate configurations outperformed the reference, increasing thermal efficiency by 15.9%–32.1% and 3.5%–4.1%, electrical efficiency by 13.1%–22.7% and 5.0%–5.6%, and net power output by 10.9%–23.6% and 8.4%–20.4%, respectively. Placing nozzle outlets closer to the PV roof tile rear wall improved collector performance with only minor pressure drop changes (≤19.55%). The perforated jet plate performed best when positioned 25 mm from the rear wall, as flow resistance increased parabolically (up to 13-fold). Final recommendations were based on the newly proposed electro-thermo-hydraulic performance parameter (ETHPP), reflecting energy balance and the power-to-heat cost ratio. ETHPP distributions confirm that nozzle configurations are highly justified, with values of 1.02–1.24 across all conditions, consistently outperforming the perforated jet plate variant.

Bipolar plate is one of the most important components of proton exchange membrane fuel cells, which has the basic functions of conducting electricity, supporting membrane electrode assemblies, uniformly distributing and isolating reactant gas, circulating coolant, and rapid heat dissipation. In this article, taking the micro runner flexible forming process of 316L stainless steel sheet as the research object, the influence of process parameters on the forming quality of micro flow runners is analyzed. The results show that an increase of the equipment pressure and a decrease of the soft film hardness are conducive to the improvement of the forming depth of a bipolar plate, while the holding time has a minor effect on the forming depth. Under the same loading conditions, the forming depth of a 0.1 mm thick sheet is smaller than that of a 0.075 mm sheet. An increase of the grain size reduces the difficulty of forming, and the larger the grain size, the larger the forming height and runner filling rate. However, with an increase of the grain size, the surface roughness of the bipolar plate increases and the wall thickness of some parts of the runner becomes uneven.

Plastic waste management and the fabrication of low-cost, high-performance energy storage and glucose-sensing devices are the need of the hour. This work focuses on the deposition of nickel–phosphorus (Ni–P) thin films via an ecofriendly and cost-effective electroless deposition method on waste plastic substrates obtained from used beverage cups. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) are used to investigate the surface morphology and roughness of the deposited film, respectively, revealing uniform deposition and a root-mean-square (RMS) roughness of 67.17 ± 14.5 nm. X-ray diffraction (XRD) analysis confirmed the amorphous nature of the film. Electrochemical studies demonstrated outstanding glucose-sensing performance of the fabricated flexible electrode with a high glucose sensitivity of 1.43 mA/cm²·mM and a low limit of detection of 74.86 µM within a linear range of 0.2–2 mM, along with excellent selectivity in the presence of common interfering species. Additionally, the electrode showed impressive energy storage performance for supercapacitor applications, achieving a maximum specific capacitance of 571.43 F/g at a current density of 1 mA/cm² with exceptional stability. These findings highlight a sustainable and scalable route for transforming waste plastics into high-value functional materials for next-generation flexible electronics.

The solid polymer electrolytes (SPEs) based on a mixture of iodine (I₂), potassium iodide (KI), polyvinyl alcohol (PVA), and polymer F-127 were investigated. The compositions 0.54 PVA, 0.060 F-127, 0.40 KI, and 0.04 I₂ had the maximum room temperature conductivity (8.2891 × 10⁻⁴ mS cm⁻¹) (for 0.5 g total weight). The electrolyte's ideal mobile ion density is responsible for this increased conductivity. The Vogel–Tamman–Fulcher (VTF) relationship governs the change in conductivity with temperature. These PVA-based SPEs were employed as electrolytes in perovskite-sensitized solar cells, including 10–60 weight percent KI and I₂. The short-circuit current density (J_sc) improved with increasing KI content, boosting power conversion efficiency (η), which peaked at 40 weight percent KI at 4.74%. Characterization of I–V parameters, scanning electron micrographs (SEMs), and X-ray diffraction (XRD) analysis, along with the measurement of the photostability of the prepared solar cells constitutes part of the investigation. These findings determine the performance of PVA-based SPEs in the field of energy conversion and perovskite solar cells.

This study addresses the tracking of the maximal electrical power generated in series-connected hybrid photovoltaic-thermoelectric (PV-TE) energy harvesting systems in low-power applications. The integration of PV-TE technologies in a hybrid energy harvesting system enhances electricity generation from sunlight by combining the properties of PV cells with the thermoelectric effect in thermoelectric generators. However, the inherent differences in electrical characteristics between the photovoltaic cell and the thermoelectric generator pose challenges in achieving the maximum power point (MPP) for the overall hybrid system. This work reviews the potential of the “differential power processing” (DPP) approach, as well as the associated architectures, DC–DC converter topologies, and maximum power point tracking (MPPT) algorithms. The final goal of this study is to identify the most suitable solutions for low-power hybrid PV-TE systems connected in series, implementing the DPP approach.

In this work, nanocomposites of graphenated carbon nanotubes (g-CNTs) conformally coated with TiO₂ by atomic layer deposition (ALD) were produced. g-CNT forests were grown on silicon substrates by microwave plasma–enhanced chemical vapor deposition (915 MHz), and the density of graphene foliates was tuned by adjusting the growth time at 1050°C. TiO₂ thickness was controlled via the number of ALD cycles. The resulting electrodes comprise aligned, high-aspect-ratio nanotube arrays whose average diameter varies with the foliate thickness and the TiO₂ cycle number. Electrochemical impedance spectroscopy and cyclic voltammetry show that the TiO₂ coating improves cyclic stability and increases specific capacitance relative to pristine g-CNTs. This enhancement arises from the synergy between the high conductivity and electric double-layer capacitance of g-CNTs and the Faradaic pseudocapacitance of TiO₂. Finally, we identify a trade-off between foliate density and TiO₂ thickness that defines a tunable parameter space for optimizing g-CNT/TiO₂ electrodes.