Carbon Neutralization最新文献

This study explored thermal and electrodeposition impacts of distinct chaotic current waveforms to enhance current efficiency and reduce heat loss through the regulation of electrode interfacial reaction dynamics, advancing current efficiency, energy conservation, and carbon neutrality. Two universal control methodology was developed to achieve independent amplitude and offset boosting of arbitrary chaotic signals, implemented through a specially designed chaotic circuit. Three distinct waveforms (w-, F-, and G-signals) were systematically investigated for their thermal and electrochemical effects. Experimental and COMSOL simulation results demonstrated that Joule heating was governed by both fluctuation amplitude and frequency characteristics, following the sequence w < F < G. When the current density was about 1500 A/m², the corresponding optimal voltage fluctuations were identified as 2.8 V (w), 0.51 V (F), and 0.23 V (G), yielding current efficiency improvements of 2.2%, 0.7%, and 5.1%, respectively, based on the electrodeposition experiments. Combining experiments on electrolytes at different temperatures with corresponding SEM characterization revealed that chaotic current suppresses manganese nodules not only through Joule heating-induced temperature rise, but also via effective regulation of the interfacial electrochemical environment, thus allowing effective inhibition even at lower temperatures. These findings provide both theoretical insights and practical methodologies for implementing chaotic currents in industrial electrodeposition processes.

V-based materials, with the high specific capacity and multi-electron redox reactions, are considered as preferred cathodes for low-cost and high-safety aqueous zinc-ion batteries. Nevertheless, poor electronic conductivity, sluggish kinetics, vanadium dissolution, and unstable structure pose severe challenges for the further practical applications. To address these issues, in this study, transition metal ions Mo⁶⁺ and polyaniline were incorporated into V₂O₅ derived from vanadium acetylacetonate via a one-step hydrothermal method (MPVO). The results reveal that MPVO exhibits a unique three-dimensional (3D) sea urchin-like morphology with a satisfactory specific surface area and high concentration of oxygen vacancies. These characteristics offer more reaction sites for Zn²⁺ and adjust the electronic conductivity. Moreover, kinetic analysis and density-functional-theory calculations indicate that MPVO performs metallic behavior, with the lowest Zn²⁺ diffusion barrier and outstanding pseudocapacitive storage capacity. Hence, the MPVO cathode delivers a reversible capacity of approximately 457.5 mAh g⁻¹ at 0.1 A g⁻¹. Moreover, it demonstrates remarkable high-rate capacity and robust long-cycle performance. This study realizes a triple-strategy approach of enlarging the interlayer spacing, evolving from a zero-dimensional (0D) to 3D sea urchin-like morphology, and introducing abundant defects. These synergistic strategies significantly enhance the rapid kinetics and high stability of the MPVO cathode and provide new insights for designing V-based cathodes.

Wide-bandgap (WBG) perovskite solar cells (PSCs) are critical for tandem architectures but suffer from light-induced halide segregation and non-radiative recombination. Although conventional rare-earth doping passivates defects, it concurrently introduces vacancies and lattice strain that exacerbate halogen migration. Herein, we report a thermally induced doping strategy where Pr³⁺/Sm³⁺ ions pre-embedded in MeO-4PACz diffuse into the perovskite during annealing. Through combined tolerance factor analysis, structural characterization, and DFT calculations, we identify a dual doping mechanism: predominant interstitial incorporation with minor B-site substitution. This approach reduces defect density, increases iodine migration energy barriers (from 0.85 to 0.94 and 1.12 eV), and minimizes lattice distortion. Consequently, the experimental results show that the open-circuit voltage increases from 1.198 V to 1.230 V (Pr³⁺) and 1.233 V (Sm³⁺), and the fill factor increases from 83% to 86%. Finally, the PCE reached 23.04% (Pr³⁺) and 23.39% (Sm³⁺) (20.12% for control) with > 90% stability retention after 1500 h. In addition, the optimized semitransparent WBG device PCE was 19.48% (Pr³⁺) and 19.85% (Sm³⁺), and the PCE of 4-T perovskite was 27.05% (Pr³⁺) and 27.56% (Sm³⁺). This method will be beneficial for the development and application of WBG PSCs and TSCs.

SnSe₂ is a promising thermoelectric (TE) material with intrinsic n-type characteristics and a high theoretical ZT value of 2.95 along the a-axis. However, its densely packed crystal lattice in the plane perpendicular to the c-axis leads to weak phonon scattering, limiting improvements through conventional defect or nanostructure-based strategies. In this study, the rare-earth element Yb is introduced into tin-rich SnSe₂, predominantly segregating at grain boundaries and enhancing phonon scattering, while a small fraction incorporates into the lattice and modifies the electronic structure, simultaneously tuning both electrical and thermal transport behaviors. Yb incorporation enhances multiple phonon scattering mechanisms, significantly reducing lattice thermal conductivity, reaching a minimum of ~0.48 W·m⁻¹·K⁻¹. Meanwhile, it modulates the electronic structure by introducing impurity states, altering band alignment, and enhancing band degeneracy, collectively increasing the density-of-states (DOS) effective mass and Seebeck coefficient, contributing to a maximum power factor of 436.47 μW·m⁻¹·K⁻² at 773 K. As a result, the Yb-doped SnSe₂ sample with 1.0 wt% achieves a peak ZT_max of ~0.53 at 773 K along the direction parallel to the pressing direction, representing an ~95.3% enhancement over the undoped sample. This study presents a synergistic and effective strategy for optimizing SnSe₂-based TE materials via rare-earth doping, paving the way for next-generation high-performance TE devices.

For decades, the industry has believed that spherical graphite (SG) yield correlates strongly with graphite flake size. To clarify natural graphite (NG) spheroidization mechanisms, a comprehensive evaluation was conducted by extracting intermediate products from an industrial production line and utilizing separated jet mills to simulate continuous processing in the study. Focused ion beam-scanning electron microscope (FIB-SEM) cross-sectional analysis and nanocomputed tomography (Nano-CT) imaging revealed that flakes of different thicknesses underwent distinct morphological changes (folding, bending, or fragmentation) under mechanical force, with only flakes above a critical thickness (∼2 μm) forming SG cores. Statistical correlation between thickness (measured via statistical method under SEM) and yield demonstrated that thickness—not only size—is the dominant factor, redefining “effective SG flakes” to include small but thick flakes. Therefore, prioritizing thickness protection over size preservation in grinding-flotation and spheroidization processes increased SG yield by 7% in industrial validation. The work provides new insights for high-efficiency SG production.

Aqueous zinc-ion batteries (AZIBs) have gained great attention due to their nontoxicity, low-cost, and high theoretical capacity. However, the scarcity of suitable cathode materials with excellent performance limits the practical application of AZIBs. Herein, we develop a conducting polymer (polyaniline) and divalent ions (Ca²⁺) co-intercalated method to synergistically regulate the property of V₂O₅ to enhance Zn²⁺ storage performance. The synergistic effect of co-insertion Ca²⁺ and polyaniline (PANI) not only enlarges the interlayer spacing but also regulates multiple oxidation states of vanadium, which dramatically improves the conductivity, diffusion kinetics, and structural stability of host V₂O₅. Consequently, the resultant Ca/PANI/V₂O₅•nH₂O (CPVO) as AZIBs cathodes exhibits extraordinary specific capacity of 512 mAh g^–1 (0.5 A g^–1) and cycling stability with an outstanding coulombic efficiency of around 100% after 2000 cycles (25 A g^–1). Moreover, the Zn²⁺ storage mechanism is elaborated by combining comprehensive characterizations and DFT calculations.

The development of advanced catalytic technologies for the combustion of low-concentration methane is crucial for minimizing unburned CH₄ emissions, consequently improving the eco-efficiency of natural gas vehicles and power plants. The integration of effective catalysts into existing systems with minimal modifications is of paramount importance. Porous ceramic composites offer a promising alternative to traditional powder catalysts due to their high surface area, excellent thermal stability, adjustable porosity, and prolonged catalytic durability. This study introduces a trace Pd–incorporated SnO₂ porous ceramic catalyst (Pd/SnO₂) fabricated using the spark plasma sintering (SPS) technique. The synthesis process uses a NaCl salt template to create a porous structure and graphite to improve Pd loading and dispersion on the SnO₂ surface. An optimized 10 wt.% graphite-decorated Pd/SnO₂ porous ceramic catalyst, containing a trace Pd loading of 0.17 wt.%, achieved a low T₉₀ of 427°C during methane reforming tests and maintained stable catalytic performance after multiple temperature cycling and over 900 min of continuous operation. Enhanced activity stems from two synergies: first, graphite-mediated uniform PdO dispersion boosting active site accessibility and second, PdO–SnO₂ interfacial charge transfer generating oxygen-deficient sites, accelerating CH₄ dissociation and stabilizing Pd²⁺ against deactivation. These findings highlight the potential of this approach for use in the development of durable and efficient ceramic composite–based catalysts for environmental applications.

Lithium–sulfur (Li–S) batteries face significant commercialization hurdles, predominantly due to challenges in promoting sulfur conversion reactions and simultaneously stabilizing cathode/electrolyte/anode interfaces. To tackle these issues, Fluoroisatin (FRN), as an electrolyte additive, was introduced in Li–S batteries, which dissolves in the electrolyte, undergoes partial deprotonation, and reacts with LiTFSI/lithium polysulfides. Consequently, it can regulate sulfur conversion pathways, accelerate reaction kinetics, and construct a LiF-rich solid-state electrolyte interface. The Li–S battery, with merely 0.5 wt% FRN additive and operating at −20°C, shows a high initial discharge capacity of 912 mAh g⁻¹ at 0.2 C, and it is maintained at 830 mAh g⁻¹ after 120 cycles. The potential of FRN, as a versatile electrolyte modifier, has potential for using in high-performance Li–S batteries.

Thermal quenching has long plagued rare-earth-doped luminescent materials as an inherent limitation, severely hampering their practical deployment in complex environments. Herein, novel orange-red-emitting K₃Sc(PO₄)₂:Sm³⁺ phosphors with anti-thermal quenching behavior have been successfully synthesized. The resultant samples have a trigonal crystal structure with space group P$��\bar{3}�$, where Sm³⁺ ions occupied two distinct Sc³⁺ lattice sites, inducing crystal field splitting and consequent emission peak splitting. The optimal doping concentration of Sm³⁺ ions was determined to be 5 mol%, above which concentration quenching was dominated by electric dipole-dipole interactions. Analysis of the intensity ratio between pure electric dipole and magnetic dipole transitions reveals that Sm³⁺ ions are predominantly sited at the centrosymmetric 1a lattice position of Sc³⁺. Moreover, the stable octahedral framework endowed the phosphors with unique anti-thermal quenching spectral properties, as evidenced by the integrated emission intensity at 573 K retaining 112.5% of its 298 K value. Finally, optical thermometric performance evaluated using emission transitions with distinct temperature dependencies underscores the phosphor's potential as a promising candidate for thermal sensing, thereby advancing the development of next-generation luminescent thermometry platforms.

The transition toward sustainable energy systems has accelerated the development of sodium-ion batteries (SIBs) as promising alternatives to lithium-ion batteries (LIBs), owing to their abundant sodium resources and cost advantages. However, the commercialization of SIBs for electric vehicles (EVs) remains hindered by challenges in achieving fast-charging performance, particularly at the anode. Hard carbons (HCs), widely regarded as the most practical anode materials, face intrinsic rate limitations due to their complex sodium storage mechanism, which involves a sloping region (> 0.10 V vs. Na/Na⁺) and a plateau region (0.01–0.10 V vs. Na/Na⁺), the latter posing a risk of sodium metal plating during rapid charging. This review examines the structural and kinetic factors that govern the fast-charging performance of HC anodes. The relationships among HC formation, microstructure, and sodium storage mechanisms are highlighted to clarify how structural features dictate electrochemical behavior. Key factors limiting rate capability, including electronic and ionic conductivity, as well as Na⁺ desolvation and diffusion, are critically assessed. Recent advances in material design, such as precursor optimization, heteroatom doping, closed-pore structure regulation, metal atom modulation, and surface coating, are evaluated to identify strategies for enhancing Na⁺ transport. Progress in electrode–electrolyte interphase engineering, particularly through electrolyte optimization and HC surface modification for stable SEI formation, is also summarized. By linking fundamental kinetics with practical design, this review provides insights for developing high-performance HC anodes and accelerating the deployment of fast-charging SIBs in next-generation EVs.