High-performance Energy Research Articles

Hierarchical H-bonding and metal coordination bonds enabled supramolecular dual networks for high-performance energy-dissipation

Natural organisms have superior material properties such as mechanical adaptability, impact protection, and self-healing to protect the body from complicated external environments, fascinating the development of functional supramolecular elastic materials with biomimetic protective features. Herein, a dual physically crosslinked supramolecular polyurethane (PU) network with strain-hardening effect is synthesized by incorporating hierarchical hydrogen bonds (H-bond) and metal coordination bonds into an elastomer matrix. A moderate content of quadruple H-bonds is critical for achieving a prominent toughness and a considerable strain-at-break owing to the strain hardening effect enabled by the hierarchical H-bonds. When the Zn-to-pyridine coordination bonds were introduced to the supramolecular PU, the strength, toughness, and energy dissipation properties were further enhanced attributing to the dual physical crosslinking networks. The dynamic dissociation and association of the sacrificial H-bonds and Zn-to-pyridine coordination bonds induced significant strain hardening effect and enabled tremendous energy absorption and self-healing properties. Besides, the supramolecular PU elastomers and their blends were foamed via scCO2 foaming to produce supramolecular foams containing dynamic bonds. The composite foam could effectively reduce the impact force from 6085 N to 373 N and achieve an outstanding energy absorption efficiency of 93.87% owing to the synergistic effect of porous structure and dual physically crosslinked networks. This work provides an innovative strategy for designing high-performance energy absorbing supramolecular elastomers and cushioning foams with reversible bonds.

Superior energy storage properties of BiFeO3 doped NaNbO3 antiferroelectric ceramics

NaNbO3 (NN)-based dielectric ceramics for energy storage have garnered significant interest due to their high saturation polarization, low residual polarization, and superior breakdown strength (Eb). However, the low recoverable energy storage density (Wrec) and efficiency (η) significantly limited their practical application. Herein, BiFeO3 (BF) was incorporated into NN to optimize the energy storage performance. The NN-BF ceramics exhibited pronounced antiferroelectric (AFE) relaxor phase, alongside grain size reduction and Eb enhancement, which contributed to a significant increase of Wrec and η. Specially, the optimum Wrec of 4.43 J/cm³ and η of 71.51 % were achieved at the composition of 0.9NN-0.1BF. Besides, stable energy storage performance was maintained over a wide temperature range (20–120 °C). These results highlight the potential of NN-BF relaxor AFE ceramics as promising candidates for high-performance energy storage applications.

Synthesis and Characterization of Carbon Nano Sphere-doped Gd: Alpha Sb2O4 Nanostructure for High-Performance Energy Storage Applications

Background: To enhance the super capacitive properties of nanocomposites, the effective method is to combine carbon nanospheres with mesoporous structures with Gd3+:α-Sb2O4 inorganic nanocomposites (NC) to form hybrid electrodes. An as-prepared hybrid electrode material possesses increased energy density, high rate of reversibility and cyclic stability when incorporated in electrochemical cyclic voltammetric studies. Methods: In the present investigation, various wt % of C-nanospheres (Cx) (5 %, 10% and 20%) were decorated over Gd3+: α-Sb2O4 nanocomposites and were synthesized by coprecipitation method. XRD, SEM, EDX, UV-visible, and XPS are only a few of the analytical techniques used to describe the as-prepared hybrid nanocomposites. Electrochemical cyclic voltammetry was carried out in a 6 M KOH solution, three-electrode system. Results: The crystal structure and morphology of Cx: Gd3+@ α-Sb2O4 NC showed a mixed hexagonal phase and agglomerated tiny irregularly shaped morphology that appeared as the Cx concentration increased. Redshift in optical absorption peak appeared (near UV-edge), and the optical band gap (Eg) value increased from 3.53 eV to 3.65 eV. The electrochemical supercapacitor showed the highest specific capacitance of 989 F/g at the current density of 1 A/g for C20%:Gd3+@α-Sb2O4 NC compared with Cx:Gd3+@α-Sb2O4 (x = 5% and 10%) and undoped Gd3+:α-Sb2O4 NC. The change in phase angle and Rs value of 1.98 was attributed to the ideal supercapacitor properties. The cyclic stability after 5000 cycles with 79.71% capacitive retention was exhibited by C20%:Gd3+@α-Sb2O4 NC. Conclusion: The present research introduces ease of synthesis of hybrid electrode materials possessing high active surface area, increased energy density, high cyclic stability, and reversibility in an aqueous solution.

Constructing superparaelectric state for NaNbO3-based ceramics electrostatic supercapacitors

A crucial prerequisite for developing high-performance energy storage devices for high pulsed power systems is the urgent necessity to acquire dielectric ceramics with high recoverable energy density (Wrec) and ultrahigh energy efficiency (η), particularly through an environmentally friendly lead-free approach. Here, superparaelectric state with ultra-small nanodomains in NaNbO3-based ceramics is successfully induced by implementing a superparaelectric modulation strategy. This innovation not only reduces the curvature value of the polarization–electric field (P-E) curve, but also produces negligible remanent polarization (Pr) and a linear-like P-E curve, obtaining outstanding efficiency (η) of 92.2 % and high energy storage density (Wrec) of 7.05 J/cm3. This achievement not only opens new avenues for enhancing the energy storage performance of dielectric ceramics but also heralds extensive applications of this material in high-pulse power electronic devices.

Energy storage efficiency and electrocaloric performances in lead-free Ba0.87Ca0.13(Ti0.9Zr0.1)0.98(Zn1/3Nb2/3)0.02O3 ceramic

Ba0.87Ca0.13(Ti0.9Zr0.1)0.98(Zn1/3Nb2/3)0.02O3 ceramic was prepared using a solid-state reaction method. This work investigates their dielectric, ferroelectric, energy storage, and electrocaloric properties. X-ray diffraction analysis confirms a pure perovskite structure. The dielectric constant reaches a maximum of 9364 at 326 K. Enhanced total energy density, recovered energy density, and energy storage efficiency are observed between 303 K and 363 K. Artificial neural networks (ANNs) are employed for the indirect determination of large ECE and responsivity based solely on measured ferroelectric polarization (P(E,T)). This approach offers rapid and accurate predictions with minimal experimental data, significantly accelerating the characterization of novel electrocaloric materials. The maximum ECE occurs above the Curie temperature (TC) and increases with higher electric fields. The ceramic exhibits significant ECE parameters around TC with a broad electrocaloric temperature span. Various figures of merit, including relative cooling power, refrigerant capacity, and temperature-averaged entropy change, are explored under different electric fields, demonstrating the material's potential for green cooling devices. These figures improve monotonically with increasing field strength. A comprehensive analysis of the field dependence of ΔS (entropy change) confirms the second-order nature of the electric phase transition through master curve analysis. In conclusion, these lead-free ceramics exhibit promising applications in high-performance energy storage devices and solid-state refrigeration technology.

Three-dimensional hydrogel membranes for boosting osmotic energy conversion: Spatial confinement and charge regulation induced by zirconium ion crosslinking

Ion-exchange membranes have been widely used to harvest osmotic energy in the past decades. However, conventional ion-exchange membranes suffer from low output power and poor conversion efficiency due to their limited pores and high membrane resistance. Herein, a sodium alginate (SA)/3-sulfopropyl acrylate potassium salt (SPAK) hydrogel membrane which has good cationic selectivity and can effectively harvest osmotic energy is designed, yielding a maximum power density of 16.44 W/m2 under a 50-fold NaCl concentration gradient and 36.85 W/m2 with ion selectivity of 0.73 at 500-fold. Furthermore, by introducing Zr4+, post-crosslinking reaction was employed to prepare tougher hydrogel membranes at room temperature for breaking a trade-off between selectivity and permeability, boosting a maximum power density up to 25.07 W/m2 under a 50-fold NaCl concentration gradient and 121.66 W/m2 with a high cation selectivity of 0.87 at 500-fold. Importantly, the resultant SA/SPAK/Zr4+ membrane reveals excellent osmotic energy harvesting property with the largest thickness of 500 μm, exceeding other reported porous nanofluidic membranes. Theoretical calculations correlate the enhanced power density of SA/SPAK/Zr4+ membranes with the enriched Cl- and smaller pore size after the introduction of Zr4+. This work paves an avenue to design and develop the 3D hydrogel membranes for high-performance osmotic energy generators.

Making 2D Materials Sparkle in Energy Storage via Assembly.

ConspectusTwo-dimensional (2D) materials such as graphene and MXenes offer appealing opportunities in electrochemical energy storage due to their large surface area, tunable surface chemistry, and unique electronic properties. One of the primary challenges in utilizing these materials for practical electrodes, especially those with industrial-level thickness, is developing a highly interconnected and porous conductive network. This network is crucial for supporting continuous electron transport, rapid ion diffusion, and effective participation of all active materials in electrochemical reactions. Moreover, the demand for efficient energy storage in advanced electronic devices and electric vehicles has led to the need for not only thicker but also denser electrodes to achieve compact energy storage. Traditional densification methods often compromise between volumetric capacitance and ion-accessible surface area, which can diminish rate performance. As versatile building blocks, 2D materials can overcome these limitations through the assembly into complex superstructures such as 1D fibers, 2D thin films, and 3D porous networks, a capability less attainable by other nanomaterials.This Account explores the pathways from exfoliated 2D nanosheets to densely packed, yet porous assemblies tailored for compact energy storage. Focusing on graphene and MXenes, we delve into the intricate relationships between surface structure, assembly behaviors, and electrochemical performance. We emphasize the crucial role of surface chemistry and interfacial interactions in forming stable colloidal dispersions and subsequent macroscopic structures. Furthermore, we highlight how solvents, acting as spacers, are instrumental in microstructure formation and how capillary force-driven densification is essential for creating compact assemblies. With precise control over shrinkage, the customized dense assemblies can strike a balance between high packing density and sufficient porosity, ensuring efficient ion transport, mechanical stability, and high volumetric performance across various electrochemical energy storage technologies.Furthermore, we highlight the importance of understanding and manipulating the surface chemistry of 2D materials at the atomic level to optimize their assembly and enhance electrochemical behaviors. Advanced in situ characterizations with high temporal and spatial resolution are necessary to gain deeper insights into the complex assembly process. Moreover, the integration of machine learning and computational chemistry emerges as a promising method to predict and design new materials and assembly strategies, potentially accelerating the development of next-generation energy storage systems. Our insights into the assembly and densification of 2D materials provide a comprehensive foundation for future research and practical applications in compact, high-performance energy storage devices. This exploration sets the stage for a transformative approach to overcoming the challenges of current energy storage technologies, promising significant advancements in 2D materials in the field.

Advanced Porous Gold-PANI Micro-Electrodes for High-Performance On-Chip Micro-Supercapacitors.

The downsizing of microscale energy storage devices is crucial for powering modern on-chip technologies by miniaturizing electronic components. Developing high-performance microscale energy devices, such as micro-supercapacitors, is essential through processing smart electrodes for on-chip structures. In this context, we introduce porous gold (Au) interdigitated electrodes (IDEs) as current collectors for micro-supercapacitors, using polyaniline as the active material. These porous Au IDE-based symmetric micro-supercapacitors (P-SMSCs) show a remarkable enhancement in charge storage performance, with a 187% increase in areal capacitance at 2.5 mA compared to conventional flat Au IDE-based devices, despite identical active material loading times. Our P-SMSCs achieve an areal capacitance of 60 mF/cm2, a peak areal energy density of 5.44 μWh/cm2, and an areal power of 2778 μW/cm2, surpassing most reported SMSCs. This study advances high-performance SMSCs by developing highly porous microscale planar current collectors, optimizing microelectrode use, and maximizing capacity within a compact footprint.

Highly efficient and durable water electrolysis via ligand modulated interfacial assembly

Herein, we report a robust ligand-modulated interfacial assembly strategy for controllable metal doping to yield high-efficiency and durable bifunctional electrocatalysts of FeCoS-embedded hollow N-doped carbon (denoted H-FeCoS/NC) for electrocatalytic overall water splitting (EOWS). Specifically, the hollow Co-based layered double hydroxide (Co-LDH) is employed to render interfacial assembly of CoFe-PBA with tunable composition, morphology, and interface on Co-LDH, regulated by inorganic ligand. Subsequent sulfidation produces H-FeCoS/NC, manifesting outstanding OER/HER activities owing to favourable ligand-modulated Fe-doping, large specific surface area, well-dispersed FeCoS nanoparticles. DFT calculation reveals that ligand-modulated Fe-doping effectively promotes charge transfer, optimizes the intermediates/electrocatalyst interaction, and reduces OER/HER energy barriers, thus boosting the EOWS performance. The H-FeCoS/NC-assembled electrolyzer delivers a low cell voltage of 1.52 V and stably operates for 1000 h in alkaline medium, surpassing most non-noble-metal-based electrocatalysts. This work highlights a facile interfacial assembly route to engineer highly active electrocatalysts for high-performance and durable energy conversion and storage.

Machine learning-based process design of a novel sustainable cooling system

An exponential rise in cooling requirements occurred in the last few years because of rising global surface temperatures, population growth, faster urbanization, and income growth. Developing countries are facing major issues because of the larger impact of these cooling drivers. Conventional vapor compression systems are energy-demanding and involve dangerous chemicals. The current paper proposed an innovative indirect evaporative cooling system with high energy performance, less emissions, and chemical-free operation. To map the full-scale performance, a prototype was developed,and tested in a variety of outside air conditions. Then artificial neural network (ANN)-based machine learning model was developed incorporating important input parameters including outdoor air temperature, air flow rate ratio, working air temperature, and working air wet bulb temperature to predict the supply air temperature. The ANN model having nine neurons in the hidden layer exhibits excellent modeling performance with a coefficient of determination (R2) value of ∼ 1 and root mean square error of 0.046 °C, 0.06 °C, and 0.06 °C in the training, testing, and validation phases respectively. The variable significance analysis carried out by one factor at a time (OFAT) technique reveals that working air inlet temperature is the most important parameter to predict supply temperature with a significance factor of 33 %. According to the combined experimental and ML model, the proposed system generated 130 W of cooling capacity and dropped the temperature by more than 20 °C at 48 °C of outdoor air. The corresponding coefficient of performance achieved (just for cooling) was 32. It is also shown that the enhanced IEC operates steadily in ambient temperatures ranging from 30 to 48 °C and maintains supply air temperatures within the comfort zone of ASHRAE-55 and ISO7730.

Wood-derived biochar as a matrix for cost-effective and high-performing composite thermal energy storage materials

Wood-derived biochar as a matrix for cost-effective and high-performing composite thermal energy storage materials

Enhanced energy storage density and efficiency of nanocomposite dielectrics by modifying polymer matrix and aminated boron nitride nanosheet

Polymers and fillers with high dielectric constant (εr), charge-discharge efficiency (η) and breakdown strength (Eb) are fundamental to the development of nanocomposite dielectrics for superior energy storage capabilities. Herein, high-εr P(VDF-TrFE) is used to prepare the P(VDF-TrFE)-g-PMMA matrix with elevated εr and η, then the P(VDF-TrFE)-g-PMMA/BNNS-NH2 nanocomposites with uniformly oriented distribution of h-BN is obtained by a squeegee casting process using amino-boron nitride (BNNS-NH2) as fillers. Thanks to the limiting effect of PMMA and the high insulating effect of BNNS-NH2, the energy storage density (Ue) of the nanocomposite is up to 15.1 J/cm3 at 500 MV/m, which is 358 % and 182 % of the original P(VDF-TrFE). Furthermore, the η could reach to 72 %, being 184 % of neat polymer. These results demonstrate that the coordinated enhancement of Ue and η is critical for high performance energy storage, which provide scientific and technological support for the practicability of PVDF-based dielectrics.

Optimized energy storage with hydrothermally synthesized metal sulfide nanocomposite electrodes

Supercapacitors exhibit impressive energy storage capabilities, providing high power density and quick charge/discharge cycles across various applications, including electronics and renewable energy systems. Molybdenum disulfide (MoS2) plays a crucial role in enhancing supercapacitor performance through its high surface area, conductivity, and electrochemical stability. Recent reports have shown that manipulating phase transitions and incorporating dopants or substitutions can significantly enhance the performance of 2D materials. The present study investigated the influence of tungsten substitution on the phase changes and electrochemical properties of MoS2. The hydrothermal synthesis process involved the substitution of tungsten with different concentration, leading to a notable phase change from 2 H to 1 T, as confirmed by X-ray diffraction (XRD) analysis. Morphological studies using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) revealed modifications in the morphological structure. The electrochemical performance of pristine MoS2 and MoS2/WS2 composites were evaluated using cyclic voltammetry (CV), chronopotentiometry (CP), and electrochemical impedance spectroscopy (EIS). The determined specific capacitances of MoS2/WS2 composites exhibited higher values compared to pristine MoS2. Specifically, the sample with 15 mol% tungsten addition demonstrated a maximum specific capacitance of 333 F g−1, surpassing that of pristine MoS2 and other samples at a current density of 1 A g−1. This research provides valuable insights into the phase-dependent electrochemical behaviour of MoS2 with tungsten substitution, offering a better understanding of its potential for applications in high-performance energy storage devices.

Phosphorous - Containing Activated Carbon Derived From Natural Honeydew Peel Powers Aqueous Supercapacitors.

The introduction of phosphorous (P), and oxygen (O) heteroatoms in the natural honeydew chemical structure is one of the most effective, and practical approaches to synthesizing activated carbon for possible high-performance energy storage applications. The performance metrics of supercapacitors depend on surface functional groups and high-surface-area electrodes that can play a dominant role in areas that require high-power applications. Here, we report a phosphorous and oxygen co-doped honeydew peel-derived activated carbon (HDP-AC) electrode with low surface area for supercapacitor via H3PO4 activation. This activator forms phosphorylation with cellulose fibers in the HDP. The formation of heteroatoms stabilizes the cellulose structure by preventing the formation of levoglucosan (C6H10O5), a cellulose combustion product, which would otherwise offer a pathway for a substantial degradation of cellulose into volatile products. Therefore, heteroatom doping has proved effective, in improving the electrochemical properties of AC-based electrodes for supercapacitors. The specific capacitance of HDP-AC exhibits greatly improved performance with increasing carbon-to-H3PO4 ratio, especially in energy density and power density. The improved performance is attributed to the high phosphorous doping with a hierarchical porous structure, which enables the transportation of ions at higher current rates. The high specific capacitance of 486, and 478 F/g at 0.6, and 1.3 A/g in 1 M H2SO4 electrolyte with a prominent retention of 98.5 % is observed for 2 M H3PO4 having an impregnation ratio of 1 : 4. The higher yield of HDP-AC could only be obtained at an activation temperature of 500 °C with an optimized amount of H3PO4 ratio. The findings suggest that the concentration of heteroatoms as surface functional groups in the synthesized HDP-AC depends on the chosen biomass precursor and the processing conditions. This work opens new avenues for utilizing biomass-derived materials in energy storage, emphasizing the importance of sustainable practices in addressing environmental challenges and advancing toward a greener future.

Mechanism of chloride modification ambipolar polymer electrode materials for high-performance energy storage device

Ambipolar conducting polymer electrode materials exhibit a wide voltage window, contributing to fast development of high-energy–density storage devices. The doping levels of p-doped and n-doped in ambipolar conducting polymers determine the electrochemical performance of energy storage devices. However, n-doped materials always face low doping efficiency, caused by difficulty in electron injection and ion migration, thereby affecting specific capacitance and stability. In this study, two ambipolar conductive polymers were developed, in which the n-doped imine group was chlorinated to improve electron injection, and the mechanism of ion migration process was studied by changing the chlorination of different positions relative to the carbonyl group. The influence of chloride modification on n-doped electrochemical energy storage was thoroughly investigated. The results show that chloride modification can lower the lowest unoccupied molecular orbital (LUMO) energy level of the monomer and make electron injection easier. Interestingly, the chloride modification position not only affects the oxidation–reduction of the carbonyl, but also the binding of the carbonyl with lithium ions. If the chloride modification position is too close to the carbonyl, lithium-ion migration in ambipolar conducting polymer will be restricted, although electron injection is beneficial. Based on this design, the developed PEPCl conducting polymer exhibits excellent electrochemical performance, and the mechanism of chlorination modification of ambipolar polymer electrode materials is described.

Interplay of physical and textural properties in porous, nanostructured hard‑carbons as electrode materials for non-Faradic energy storage devices

This work presents a systematic investigation on the non-Faradic energy storage ability of non-graphitizable, porosity engineered hard‑carbon nanostructures as electrode materials. The persistent challenge of inducing and tuning porosity in hard‑carbon nanostructures is overcome here, by utilizing dendritic fibrous nano silica (DFNS) as a sacrificial template for uniform and conformal deposition of carbon through thermal chemical vapor deposition, leading to the formation of porosity tuned, nanostructured hard‑carbon florets (NCF). This strategy enables precisely crafted six varieties of NCF with varying yet monodisperse dimensions (NCF 90, NCF 350, NCF 366, NCF 430, NCF 540 and NCF 600), SSA (494–719 m2/g) and textural features such as pore volume (0.67–1.24 cm3/g) and pore diameter (3.83–5.65 nm). In contrast to current understanding, NCF 366 with defect length of 16 nm, defect density of 2.65 × 1011 cm−2, micro- to mesoscale pore ratio of 0.16 and specific surface area of 535 m2/g achieves the highest energy density of 14.6 Wh/kg and power density 10.0 kW/kg, when compared to NCF 90 with higher SSA (719 m2/g) and pore volume (1.24 cm3/g). Thus, this work manifests the critical contributions of tuning the pore structures and optimizing the relative contributions from multi-scale pore structures to achieve high-performing energy storage devices.

The influence of divalent ions on the osmotic energy conversion performance of 2D cation exchange membrane in reverse electrodialysis process

As reverse electrodialysis (RED) technology evolves, achieving high-performance osmotic energy conversion (OEC) necessitates porous membranes with exceptional ion selectivity and permeability. Two-dimensional membranes crafted from graphene oxide (GO) or MXene stand out for their immensely high surface charges, which facilitate superb ion selectivity during transport. Their unique layered stacking structure further yields ultra-small nanochannel radii, bolstering ion selectivity while maintaining high permeability. This makes them prime candidates for osmotic energy conversion. However, the presence of divalent ions in natural seawater readily alters the surface charge density and interlayer spacing of these 2D membranes, significantly impacting their OEC performance, resulting in a power density reduction of about 6 % -10 %. Prior research focused on the ionic properties of divalent ions but overlooked their impact on the nanochannel structure, including changes in interlayer spacing and surface charge density. This study thus delves into the OEC performance variations of GO and MXene 2D layered membranes under varying divalent ion concentrations and salt ratios. Starting from the ion properties of divalent ions and their impact on the nanochannel structure, combined with simulation research, explain their mechanism of action. This research offers theoretical foundations for the future design and application of 2D layered membranes, providing novel solutions and insights to tackle critical challenges like enhancing power density and adapting to real seawater conditions.

Self-Exfoliating Benzotristriazine Macrocyclic Network: A New 2D Material for High-Performance Electrochemical Energy Storage.

Aza-fused aromatic π-conjugated networks are an important class of 2D graphitic analogs, which are generally constructed using aromatic precursors. Herein, the study describes a new synthetic approach and electrochemical properties of a self-exfoliating benzotristriazine 2D network (BTTN) constructed using aliphatic precursors, under relatively mild conditions. The obtained BTTN exhibits a nanodisc-like morphology, the self-exfoliation tendency of which is ascribed to the presence of structurally different macrocycles with high electronic repulsion between the layers. The benzotristriazine repeat units of BTTN is electroactive and holds higher carbon/nitrogen ratio when compared with the conventional graphitic aza-fused π-conjugated networks. The self-exfoliated BTTN nanodiscs show excellent electrochemical energy storage of 485 and 333 F g-1 at 1 A g-1 in three-electrode and two-electrode measurements, respectively. BTTN in a symmetric coin-cell architecture exhibits a high specific energy value of 46Wh kg-1 at a power density of 1kW kg-1 and shows excellent cyclic stability of 96% for 10000 and 90% for 30000 charge-discharge cycles at a higher current density of 5 A g-1, surpassing the device performance of most of the reported all-organic pseudocapacitive 2D networks.

Optical investigation on lubricant combustion characteristics under the ammonia-methane premixed environment

The combustion process is an indispensable energy conversion step in modern industry and energy production. Especially in high-performance engines and energy conversion systems, understanding and controlling the combustion process is critical to improving efficiency and reducing environmental pollution. As a key component of mechanical systems, the combustion characteristics of lubricants at high temperatures and pressures have a direct impact on system performance and emissions. This study investigated the combustion characteristics of lubricant films in an ammonia-methane premixed environment using Planar Laser-Induced Fluorescence (PLIF) and Planar Laser-Induced Incandescence (PLII). It focused on the effects of varying ammonia concentrations on the emission of soot and polycyclic aromatic hydrocarbons (PAHs) in the constant volume combustion vessel. Experiments varied the ammonia-to-methane molar ratios, initial oil film thickness, and base oil type to study their influence on the lubricant combustion characteristics. Results indicated that ammonia significantly reduced soot formation by altering the dynamics of NH* and OH* and impacting PAH distribution. For the lubricating oil soot formation factors, the increase of the initial mean oil film thickness was more obvious for the promotion of soot formation, the increase of the unsaturated hydrocarbon content in the oil film also promoted the generation of carbon soot to a certain extent, and the initial flame energy ratio had the least influence on the promotion of soot formation. Overall, the study contributed to the understanding of the formation mechanism of soot caused by lubricating oil in zero-carbon and low-carbon blended atmospheres and provided a new insight into the interaction between nitrogen-containing zero-carbon fuels and large-carbon-number hydrocarbons, which is of great significance for controlling soot emissions from engines under zero-carbon fuel blending.

Novel NH4V4O10-Reduced Graphene Oxide Cathodes for Zinc-Ion Batteries: Theoretical Predictions and Experimental Validation

This investigation explores the potential of enhancing aqueous zinc-ion batteries (AZIBs) through the introduction of a novel cathode material, NH4V4O10 (NVO), combined with reduced graphene oxide (rGO). Utilizing Density Functional Theory (DFT), it was hypothesized that the incorporation of rGO would increase the interlayer spacing of NVO and diminish the charge transfer interactions, thus promoting enhanced diffusion of Zn2+ ions. These theoretical predictions were substantiated by experimental data acquired from hydrothermal synthesis, which indicated a marked increase in interlayer spacing. Significantly, the NVO–rGO composite exhibits remarkable cyclic durability, maintaining 95% of its initial specific capacity of 507 mAh g−1 after 600 cycles at a current density of 5 A g−1. The electrochemical performance of NVO–rGO not only surpasses that of pristine NVO but also outperforms the majority of existing vanadium oxide cathode materials reported in the literature. This study underscores the effective integration of theoretical insights and experimental validation, contributing to the advancement of high-performance energy storage technologies.