Energy & Fuels最新文献

Accurate estimation of battery state of health (SOH) is crucial for ensuring the safety and reliability of electric vehicles (EVs). However, the low-quality field data and the scarcity of reliable SOH labels hinder the development of SOH estimation methods. This study proposes a SOH estimation framework based on a patch cross-variate Transformer (PatchCVT) architecture. First, a multifactor correction method is developed for capacity calculation. It improves the reliability of SOH labels under varying operating conditions. Then, a local patching strategy and a cross-variate attention mechanism are designed to capture temporal dependencies in battery degradation as well as interactions among input features. To further enhance the model’s performance, a masked self-supervised pretraining strategy is introduced. It leverages unlabeled data and learns generalizable feature representations. Finally, the framework is validated using 1 year of real-world operational data collected from 41 EVs. Results show that PatchCVT achieves an estimation root-mean-square error (RMSE) of 0.894%, representing the lowest error metrics among all baseline models. This error further decreases to 0.729% after pretraining. Moreover, the framework is extended to cross-domain transfer tasks. A pretrained PatchCVT fine-tuned on target data achieves comparable performance to its supervised-transfer version, with the RMSE differing by only 0.353%. These results underscore its applicability to large-scale field data and offer a viable solution for battery health management.

Utilizing spiro-OMeTAD as a hole transport material (HTM) in perovskite solar cells (PSCs) has demonstrated an excellent device efficiency. However, the increasing commercial cost of spiro-OMeTAD highlights the need for gainful alternatives. This study used a donor–acceptor–donor′ (D–A–D′) architecture to develop two carbazole-based compounds, MK01 and MK01-alkyl. The acceptor (A) unit is a cyanopyridone or cyanopyridine ring, while the donor (D) and donor′ (D′) units are fluorene and N-ethylcarbazole rings, respectively. These compounds were synthesized from readily available starting materials at an estimated cost of $12.90/g for MK01 and $25.82/g for MK01-alkyl, substantially lower than the $400/g cost of spiro-OMeTAD. Photophysical studies revealed absorption maxima (λ_abs) at 386 nm (MK01) and 352 nm (MK01-alkyl), with emission maxima (λ_em) at 556 nm (MK01) and 520 nm (MK01-alkyl), respectively, in solution. The absolute quantum yields of MK01 and MK01-alkyl were 19.55% and 71.50%, respectively, in DMSO, while in the solid state, they were 1.84% and 15.50%. Thermogravimetric analysis showed a 5% weight loss at 401 °C for MK01 and 378 °C for MK01-alkyl, and the corresponding glass transition temperatures (T_g’s) were 173 and 119 °C, respectively. Electrochemical analyses showed that their HOMO energy levels were compatible with perovskite valence bands and that LUMO levels were sufficient for electron-blocking functionality. Further, all these experimental findings were well supported by DFT calculations. Moreover, MK01-alkyl exhibited hole mobility (3.5 × 10^–5 cm² V^–1 s^–1), while MK01 films showed minimal charge transport and no detectable photoresponse.

In biomass pyrolysis, final product selectivity is governed not only by major reaction conditions like temperature and heating rate but also by complex vapor–solid interactions and secondary reactions. Yet, the influence of internal flow configuration on pyrolysis vapor remains poorly understood in continuous pyrolysis systems. This study aims to evaluate how controlled vapor–solid interactions via changes in the vapor outlet port location affect the distribution and transformation of pyrolysis products. Experiments were performed in a continuous laboratory-scale auger reactor, processing pine bark at highest treatment temperatures (HTT) of 600, 700, and 800 °C. The reactor featured five independently heated zones and six selectable vapor outlet ports, enabling three vapor flow modes: parallel flow (PF, conventional cocurrent flow operation) and two counterflow (CF) configurations to systematically manipulate vapor–solid contact. Results showed that one of the CF configurations, where vapors passed through the coldest (the incoming) biomass zone before exiting, enhanced vapor condensation on incoming biomass and promoted secondary reactions, leading to up to a 15.5% relative increase in biochar yield compared to PF. The increase in biochar yield was accompanied by an increase in fixed carbon yield, and H₂ and CH₄ yields, indicating intensified thermal cracking and polymerization of pyrolysis vapors. In contrast, the CF configuration involving vapor recirculation without interaction with the coldest zone favored external condensation and achieved the highest bio-oil recovery. The PF configuration exhibited the lowest char yield and the highest unaccounted carbon fraction due to poor vapor condensation at elevated outlet temperatures. These findings demonstrate that the manipulation of vapor–solid interactions serves as a critical parameter for steering pyrolysis pathways toward targeted product enhancement, offering a scalable approach for optimizing biochar, gas, and bio-oil yields through in situ vapor recirculation.

Modulating anionic oxygen in metal oxides through doping offers transformative potential for enhancing oxygen carriers in chemical looping processes by improving the redox performance and addressing challenges such as sintering and carbon deposition at high temperatures. Doping introduces oxygen vacancies and lattice strain, enhancing the oxygen mobility for the selective oxidation of fuels into desired products. The performance of oxygen carriers is critically influenced by the dopant type, concentration, and distribution; excessive doping leads to agglomeration and structural degradation, while insufficient doping results in suboptimal reactivity. Co-doping and doping in supports provide synergistic benefits, improving the oxygen transport, stability, and selectivity. This review explores the impact of dopant concentration, codoping, and support doping on oxygen carrier performance, emphasizing the need for optimal doping strategies to balance structural integrity and redox efficiency. It highlights advancements and case studies demonstrating selective fuel oxidation, offering insights into optimizing the oxygen carrier design for sustainable energy applications.

Water electrolysis (WE) powered by renewable energy represents a pivotal pathway for large-scale hydrogen production. However, its heavy reliance on scarce, high-purity freshwater increasingly conflicts with global water-stress realities. Thus, the direct use of abundant nonpure water sources, such as seawater and salt-lake water, has emerged as a critical research frontier. This perspective provides a comprehensive, cross-technology analysis of the underlying principles, technical challenges, and recent advances in this field. First, alkaline, proton exchange membrane (PEM), anion exchange membrane (AEM), and solid oxide electrolysis pathways were compared, considering water-quality tolerance, energy efficiency, and durability. Subsequently, the specific chemistry of seawater and salt-lake electrolytes was examined, highlighting chloride-induced anode corrosion, competitive chlorine evolution, and cathodic mineral deposition as dominant failure modes. The state-of-the-art mitigation strategies were systematically summarized: (i) protective layers (MnO_x, and Lewis-acidic oxides) that selectively block Cl^– while preserving oxygen evolution reaction (OER) kinetics; (ii) oxygen-containing anion (PO₄^3– and SO₄^2–) modification of layered double hydroxides to repel chloride via electrostatic and intercalation effects; (iii) chloride-induced surface reconstruction that unexpectedly activates lattice-oxygen–mediated oxygen evolution reaction pathways; and (iv) system-level designs including highly alkaline electrolytes, permselective chloride-blocking anodes, pH-asymmetric cells, and decoupled redox cycles. Finally, we outline key remaining gaps and future research directions, offering guidance for advancing sustainable hydrogen production from nonpure water sources.

Injecting CO₂ into low-permeable reservoirs can not only improve oil recovery but also achieve CO₂ storage, which has both economic and environmental benefits. The current study on coupled optimization of the CO₂ enhanced oil recovery (EOR) and enhanced CO₂ storage (ECS) primarily relies on numerical simulations. However, the optimization method considering the combined impact of multiple factors for CO₂ EOR and ECS is insufficient. To improve the efficiency of oil recovery and CO₂ storage during the CO₂ flooding process, the Box-Behnken design (BBD) and response surface method (RSM), combined with simulations of CO₂ flooding and storage, are conducted to reveal the coupled optimization effect of CO₂-enhanced oil recovery (CO₂-EOR) and enhanced CO₂ storage (ECS) within reservoirs. The results indicate that the sensitivity ranking of the induced factors on CO₂-EOR and ECS is the same as C (CO₂ injection method) > A (CO₂ injection rate) > B (CO₂ injection stage) > D (reservoir permeability). From the RSM analysis results, the oil recovery is mainly influenced by the interaction effect of factors AC and BC. However, the interaction effect of AC and CD on the CO₂ storage percentage in reservoirs is more significant. In the low water cut stage, the CO₂-EOR effect does not significantly differ under different CO₂ injection methods. However, as the water cut of reservoirs exceeds 50%, the difference in oil recovery becomes significant with the best displacement method of continuous CO₂ injection. In the high water cut stage, severe water locking occurred, and the CO₂ sweep volume in reservoirs was low by CO₂ huff and puff (CO₂ HnP) and CO₂-water-alternating (CO₂–WAG) injection, which inhibited the mass transfer between CO₂ and crude oil. The change in permeability of reservoirs has little effect on CO₂-EOR and ECS for low-permeability reservoirs. The optimized scenario for CO₂-EOR and ECS is with the reservoir permeability of 10 mD, a water cut of 30%, CO₂ HnP, and daily CO₂ injection of 9770.60 m³. The optimal scenario significantly improves oil recovery, reaching 87.89% and CO₂ storage percentage at 76.82%.

Aqueous zinc-ion batteries (AZIBs) show great promise for large-scale energy storage applications thanks to their excellent safety performance and low cost. However, their development is hindered by the limited availability of high-performance cathode materials. In this study, amorphous vanadium oxide (A-VO_x/NC) coated with nitrogen-doped carbon was produced using a nitriding strategy and subsequent electrochemical oxidation process with delaminated V₂CT_x MXene as the precursor. Material characterization confirmed that the resulting A-VO_x/NC had inherited the MXene precursor’s desirable layered morphology and formed a disordered amorphous structure. Within this tailored structure, the layered structure provides a large accessible site for the Zn redox reaction, while the amorphous structure offers isotropic ionic migration pathways for Zn-ion intercalation/deintercalation. Meanwhile, the nitrogen-doped carbon layer boosts the material’s conductivity and acts as stable “armor” to suppress vanadium dissolution in electrochemical reactions. Consequently, the A-VO_x/NC material exhibits exceptional electrochemical properties when used as a cathode in AZIBs, delivering a high specific capacity of 527.35 mAh g^–1 at 0.2 A g^–1, maintaining excellent rate capability (117.14 mAh g^–1 even at 50 A g^–1), and demonstrating outstanding cycling stability, retaining 91.67% of its capacity after 3000 cycles at 50 A g^–1. Further strong evidence confirms the conventional H⁺/Zn²⁺ cointercalation/deintercalation charge storage mechanism in the A-VO_x/NC cathode. This work expands the application of MXene-derived materials in electrochemical energy storage and provides a general strategy for regulating the crystallinity and microstructure of cathode materials. This is useful for designing advanced AZIB cathodes.

A systematic study on the competitive oxidation of glucose (Glc), xylose (Xyl), and 5-hydroxymethylfurfural (HMF) vs the oxygen evolution reaction (OER) was performed by coupling H-cell electrochemical experiments with in situ O₂ monitoring in the anodic chamber using an activated Ni foam as the anode. At a substrate concentration of 10 mM, multipotential steps showed similar OER onset potential values for Glc and Xyl (1.49 V_RHE), while the value for HMF was slightly lower (1.47 V_RHE). Chronoamperometry tests at 1.6 V_RHE (30 min) with varying concentrations showed that both Glc and Xyl oxidation reactions fully suppressed the OER at 30 mM, while 100 mM was required for HMF. A Langmuir–Hinshelwood analysis of the current–substrate concentration dependence revealed the slower kinetics and inhibitory effects impacting HMF oxidation, which account for the significant difference in performance with respect to both aldoses. Given its relevance as both a model and a promising substrate for membraneless electrolysis operation, Glc was further investigated in a long-term chronoamperometry experiment with in situ O₂ monitoring (15 h at 1.6 V_RHE, 30 mM Glc). The results suggested the feasibility of sustaining OER-free operational conditions for approximately 4 h from an initial Glc concentration of 100 mM. HPLC analysis indicated the presence of formate as the main coproduct of hydrogen via glucose electrolysis.

Rechargeable zinc-air batteries (ZABs) are attractive for energy storage, but their efficiency is limited by the slow kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Here, we report a bifunctional single-atom catalyst consisting of atomically dispersed iron anchored on N-doped two-dimensional (2D) carbon nanosheets (Fe-NCS-800) for high-performance ZABs. This material was sustainably synthesized through the graphene-oxide (GO)-induced hydrothermal carbonization of hemicellulose, followed by copyrolysis with NH₄Cl and FeCl₃ and subsequent acid leaching. The resulting architecture comprises interconnected porous nanosheets with a substantial surface area (1436 m² g^–1), facilitating mass transport and exposing abundant active sites. Advanced characterization techniques, including aberration-corrected scanning transmission electron microscopy (AC-STEM) and X-ray absorption spectroscopy, confirmed the dominant presence of FeN₄ coordination sites. Under alkaline conditions, Fe-NCS-800 outperformed Pt/C in the ORR with a half-wave potential (E_1/2) of 0.87 V vs RHE, while also exhibiting appreciable OER activity, resulting in a low bifunctional index (ΔE) of 0.83 V. When used as the air cathode in Zn-air batteries, it reached a peak power density of 215 mW cm^–2 and a specific capacity of 766 mA h g^–1, maintaining stable operation for over 400 h. These results show a sustainable strategy for developing efficient biomass-derived single-atom electrocatalysts for next-generation metal-air batteries.

Researchers based in different European countries are actively developing nanocellulose membranes as sustainable alternatives to conventional membranes used in both hydrogen fuel cells and anion- and proton-exchange membrane electrolyzers. Focusing on recent innovations, this study offers a European perspective on research on nanocellulose-based ion-exchange membranes for new-generation hydrogen fuel cells and water electrolyzers. The study highlights also how research policy promoting a cross-disciplinary and cooperative approach to research enabled the innovation behind the development of these enhanced membranes. Perspective is timely as research efforts conducted in European and in non-European countries in the past decade (2015–2025) are approaching technology commercialization.