Thermodynamic Perspective Research Articles

Practical evaluation of prelithiation strategies for next‐generation lithium‐ion batteries

AbstractWith the increasing market demand for high‐performance lithium‐ion batteries with high‐capacity electrode materials, reducing the irreversible capacity loss in the initial cycle and compensating for the active lithium loss during the cycling process are critical challenges. In recent years, various prelithiation strategies have been developed to overcome these issues. Since these approaches are carried out under a wide range of conditions, it is essential to evaluate their suitability for large‐scale commercial applications. In this review, these strategies are categorized based on different battery assembling stages that they are implemented in, including active material synthesis, the slurry mixing process, electrode pretreatment, and battery fabrication. Furthermore, their advantages and disadvantages in commercial production are discussed from the perspective of thermodynamics and kinetics. This review aims to provide guidance for the future development of prelithiation strategies toward commercialization, which will potentially promote the practical application of next‐generation high‐energy‐density lithium‐ion batteries.

InGaN surface morphology evolution investigated by atomic force microscope with power spectral density analysis

The morphology of thin InGaN layers grown at varying temperature by metalorganic chemical vapor deposition (MOCVD) has been studied by atomic force microscope (AFM). The surface morphology undergoes a transition process from three-dimensional (3D) island growth mode to two-dimensional (2D) nucleated mound and hillock growth mode and finally to layer-by-layer step-meandering and step flow growth mode. The changes in morphology were analyzed from a thermodynamic (mostly based on the BCF theory of crystal growth by Burton, Cabrera and Frank) and kinetic (mostly the ESB theory based on the Ehrlich-Schwöbel barrier) perspective. Power spectral density (PSD) analysis of AFM surface images is used to determine the dominant smoothing mechanisms that contribute to the feature of surface morphology of InGaN, and validate our analysis based on BCF and ESB theories.

DYNAMIC REVERSIBLE NETWORKS AND DEVELOPMENT OF SELF-HEALING RUBBERS: A CRITICAL REVIEW

ABSTRACT An intensive literature search shows that research in the field of self-healing rubbers is still in its infancy. By analyzing the various reviews and reports available, most of the results prove to be complicated; however, a few studies show promising self-healing properties of new elastomers. Most of these materials were prepared by relatively sophisticated chemical syntheses. Many of the studies on self-healing materials also deal with commercial rubbers, but the mechanical performance of these self-healing systems is very poor for practical application, perhaps because self-healing systems are usually prepared with an uncured or pseudo-crosslinked matrix structure. The poor mechanical properties are related to the highly viscous but inelastic nature of the uncured or only partially cured rubber compound. Importantly, most of the studies have been conducted on rubber systems without reinforcing fillers. For filler-reinforced rubber systems, the question is whether the working principle of reversible bonds is applicable. This literature review attempted to compile the current promising self-healing systems, describe their underlying chemical mechanisms, and discuss the self-healing concept from a thermodynamic perspective. In addition, this review is focused on the critical discussion of the principle and origin of self-healing behavior and finally draws conclusions on the applications and opportunities for further developments in this field.

Thermodynamic Simulation of O Content Variation Roadmap in Submerged Arc Welding Process: From Droplet to Weld Metal

Submerged arc welding is a complex metallurgical system involving various phases with a temperature higher than 2000 °C. Since the hot weld pool is shielded beneath the flux, thermodynamic investigation on the O content variation during the welding process remains nebulous. Within this framework, a thermodynamic approach has been proposed to estimate the variation tendency of O content in metal during the overall submerged arc welding process. The modeling is based on the assumptions of Oxygen Layer Theory, Local Attained Equilibrium, and Scheil Solidification. The simulated and measured data show that this approach is capable of predicting the variation of the O content roadmap when typical CaO–Al2O3 based fluxes are employed. Then, factors pertinent to the level of O content are evaluated from thermodynamic perspectives. Additionally, it is revealed that the decomposition mechanisms of the oxides in welding can be constrained via the incumbent approach.

Quantum Dots Meet Enzymes: Hydrophobicity of Surface Ligands and Size Do Matter.

Colloidal quantum dots (QDs) are a class of representative fluorescent nanomaterials with tunable, bright, and sharp fluorescent emission, with promising biomedical applications. However, their effects on biological systems are not fully elucidated. In this work, we investigated the interactions between QDs with different surface ligands and different particle sizes and α-chymotrypsin (ChT) from the thermodynamic and kinetic perspectives. Enzymatic activity experiments demonstrated that the catalytic activity of ChT was strongly inhibited by QDs coated with dihydrolipoic acid (DHLA-QDs) with noncompetitive inhibitions, whereas the QDs coated with glutathione (GSH-QDs) had weak effects. Furthermore, kinetics studies showed that different particle sizes of DHLA-QDs all had high suppressive effects on the catalytic activity of ChT. It was found that DHLA-QDs with larger particle sizes had stronger inhibition effects because more ChT molecules were bound onto the surface of QDs. This work highlights the importance of hydrophobic ligands and particle sizes of QDs, which should be considered as the primary influencing factors in the assessment of biosafety. Meanwhile, the results herein can also inspire the design of nano inhibitors.

Intensive carbon combustion in sintering packed bed via steam spraying: An experimental study on carbon monoxide emission reduction.

Improving the combustion efficiency of solid fuels is important for reducing carbon monoxide emissions in the iron ore sintering process. In this paper, the surface steam spraying technology is introduced in the sintering process based on the auxiliary combustion effect of steam on coke, and its potential to reduce carbon monoxide emissions is demonstrated. Thermogravimetric analysis experiments of coke breeze in air and air-steam mixed atmosphere are carried out, and the results show that the introduction of steam can reduce the concentration of carbon monoxide in the exhaust gas from 183×10-6 to 78×10-6. At the same time, the mechanisms of carbon monoxide emission reduction by surface steam spraying technology are analyzed from the thermodynamic and kinetic perspectives. Then, a series of laboratory-scale sintering pot tests are carried out under no spraying operation, interval spraying operation, and continuous spraying operation. The results indicate that both interval and continuous spraying operations can reduce carbon monoxide emissions. The optimal mode of steam spraying under the present experimental conditions is continuously spraying for 13 min at a volume rate of 0.053 m3/min. Compared with no spraying, the average carbon monoxide concentration in the exhaust gas is reduced from 7565×10-6 to 6231×10-6, and total carbon monoxide emissions for per ton sinter are reduced from 13.46 m3/t to 9.51 m3/t.

Thermodynamics of Ligand Exchange with Aromatic Ligands on the Surface of CdSe Quantum Dots

Quantum dots (QDs) have great application prospects in optoelectronic devices because of their excellent optical properties. Nevertheless, the original ligands of the long carbon chain introduced in the synthesis process are not conducive to the application of CdSe QDs in optoelectronic devices due to their insulating nature. Therefore, short-chain and aromatic ligands are employed to replace the original ligands. However, the influences of conjugation structures on ligand exchange have rarely been systematically studied from a thermodynamic perspective. In this work, two types of aromatic ligands, namely, a series of benzoic acid (BA) ligands and cinnamic acid (CA) ligands that introduced electron-donating (methoxy-) and electron-withdrawing groups (fluoro-) at the meta and para positions of the benzene ring of aromatic ligands, were chosen to investigate the ligand exchanges on the surface of QDs from oleic acid (OA) to a series of aromatic ligands by 1H nuclear magnetic resonance (NMR) spectroscopy and isothermal titration calorimetry (ITC). 1H NMR showed that the average exchange ratio of CA ligands to OA was ∼1:1, which made it possible to obtain thermodynamic parameters through the determined ligand exchange model by ITC. Furthermore, thermodynamic results showed that ligand exchange with CA ligands was endothermic (ΔH > 0) and entropy-increasing (ΔS > 0), indicating that the process was entropy-driven. In addition, the equilibrium constants (K) of ligand exchange with CA ligands were larger than those with BA ligands. However, the K values of ligand exchange with BA ligands were ∼1, which resulted in ΔG ∼ 0 kJ/mol, demonstrating that ligand exchange with BA ligands was less favorable at 298.15 K. Finally, the introduction of substituents on meta and para positions of the aromatic ligand benzene ring had no significant effect on the ligand exchange process. This work not only elaborates on the process of exchange with aromatic ligands but also has fundamental significance for the application of aromatic ligand-modified QDs in optoelectronic devices.

Theoretical Study on Zigzag Boron Nitride Nanowires.

In this work, two kinds of BN-nanowires (BNnws): a-BNnw and d-BNnw, respectively composed of azo (N-N) and diboron (B-B) bonds, are proposed with the aid of the first-principles simulations. Their structural stabilities are carefully verified from the energetics, lattice dynamics, and thermodynamic perspectives. Similar to the other common boron nitride polymorph, the a-BNnw and d-BNnw are semiconductors with relatively wide band gaps of 3.256 and 4.631 eV at the HSE06 level, respectively. The corresponding projected DOS patterns point out that their band edges are composed of different atomic species, which can help with the separation of their excitons. The band gaps can be manipulated monotonically by axial strains within the elastic ranges. The major charge carriers are electron holes. Significantly, a-BNnw possesses very high carrier mobilities around 0.44×104 cm2 V-1 s-1 .

Order and Complexity in the RNA World

The basic idea of the RNA world as an early step towards life relies on a molecular evolution process based on self-replicating RNA strands. It is probably the oldest and most convincing model for efficient prebiotic evolution. Obviously, the functionality of RNA sequences depends on order (i.e., the definition of their sequence) as well as on complexity (i.e., the length of their sequence). Order and complexity seem to be crucial parameters in the course of RNA evolution. In the following, an attempt is made to define these parameters and to identify characteristic mechanisms of their development. Using a general RNA world scenario including the free monomer units, the sequential order is defined based on statistical thermodynamics. The complexity, on the other hand, is determined by the size of a minimal algorithm fully describing the system. Under these conditions, a diagonal line in an order/complexity-diagram represents the progress of molecular evolution. Elementary steps such as repeated random polymerization and selection follow characteristic pathways and finally add up to a state of high system functionality. Furthermore, the model yields a thermodynamic perspective on molecular evolution, as the development of a defined polymer sequence has a distinct influence on the entropy of the overall system.

Formation Mechanisms and Three-dimensional Characterization of Composite Inclusions in Low Aluminum Steel Deoxidized by Silicon

Silicon deoxidized steel takes a large proportion in addition to aluminum deoxidized steel, since aluminum deoxidation may cause many problems, such as nozzle clogging and low toughness. In this paper, a low aluminum silicon deoxidized steel was prepared in the laboratory. The inclusions in steel mainly include MnS and composite inclusions made of MnS and oxides. The formation of MnS and composite inclusion was discussed based on the thermodynamic calculations. It was clarified that the MnS precipitate during the solidification process of steel. In addition, the formation mechanism of the composite inclusions was illustrated from the perspective of thermodynamics and lattice mismatch. The composite inclusions in steel were reconstructed by Micro-CT and the three-dimensional (3D) morphologies were analyzed in details. This method avoids artifacts and misleading of the two-dimensional observation on the cross sections of the steel samples. Meanwhile, the 3D observation by Micro-CT is an innovation way to characterize the different phases of the inclusion simultaneously, which paved a way for the analysis of the composite inclusions in the steel.

Untangling the importance of dynamic and thermodynamic drivers for wet and dry spells across the Tropical Andes

Andean vegetation and agriculture depend on the patterns of rainfall during the South American monsoon. However, our understanding on the importance of dynamic (upper-level wind circulation) as compared to thermodynamic (Amazon basin moisture) drivers for Andes rainfall remains limited. This study examines the effect of these drivers on 3–7 day wet and dry spells across the Tropical Andes and assesses resulting impacts on vegetation. Using reanalysis and remote sensing data from 1985–2018, we find that both dynamic and thermodynamic drivers play a role in determining the rainfall patterns. Notably, we show that the upper-level wind is an important driver of rainfall across the entire Tropical Andes mountain range, but not in the Amazon lowlands, suggesting a crucial role of topography in this relationship. From thermodynamic perspective, we find wet spell conditions to be associated with increased moisture along the Andes’ eastern foothills accompanied by a strengthened South American low-level jet, with moisture lifted into the Andes via topography and convection for all considered regions. Our results suggest that while changes in Amazon basin moisture dominate rainfall changes on daily time scales associated with three day spells, upper-level dynamics play a more important role on the synoptic time scale of 5–7 day spells. Considering impacts on the ground, we find that only 5–7 day spells in the semi-arid Andes have a prolonged effect on vegetation. Our study emphasizes the need to consider both dynamic and thermodynamic drivers when estimating rainfall changes in the Tropical Andes, including in the context of future climate projections.

Thermodynamic analysis of the difference in adsorption characteristics of CH4 and CO2 on continental shale

In order to explain the difference in adsorption characteristics of CH4 and CO2 on continental shale from the perspective of thermodynamics, the isothermal adsorption experiments of CH4 and CO2 adsorbed by shale in Yanchang Formation in Ordos Basin were carried out, and the excess adsorption capacity was corrected to absolute adsorption capacity. Then the Clausius-Clapeyron equation was used to analyze the isosteric heat of adsorption of CH4 and CO2 on shale. The results show that, for calculating the absolute adsorption capacity, Ozawa empirical formula or Van der Waals approximation method should be used to calculate the adsorption phase density. The absolute adsorption capacity should be selected as the basic data for calculating the isosteric heat of adsorption. The reason is that the excess isosteric heat of adsorption has a negative value in the low adsorption capacity stage, which is contradictory to the fact that the adsorption process is exothermic, and is significantly higher than the absolute isosteric heat of adsorption. There is a good linear positive correlation between the isosteric heat of adsorption and the adsorption amount of CH4 and CO2 adsorbed by continental shale, and the isosteric heat of adsorption of CH4 is greater than that of CO2. The absolute initial isosteric heat of adsorption of CH4 and CO2 adsorbed by shale is 52.04 kJ/mol and 27.71 kJ/mol, indicating that the adsorption force of CH4 on Yanchang Formation shale is stronger than that of CO2.

Structural and thermodynamic effects of hydration in Na-zeolite A (LTA) from low-temperature heat capacity

Zeolite A (Linde Type A; LTA) is an industrially important porous mineral that has recently been shown to exhibit framework flexibility upon changes in hydration level. To investigate the flexibility transition from a thermodynamic perspective, we have performed heat capacity measurements on sodium zeolite A at seven incremental hydration levels ranging from zero to equilibrium with ambient air. Excess low-frequency vibrations beyond the predictions of the Debye model are found in all samples, and the frequency of these vibrations increases as a function of hydration level. This suggests that an increase in hydration causes a decrease in at least one type of framework flexibility for sodium zeolite A. In addition, a subtle excess heat capacity contribution from 150 to 280 K is observed only for low and intermediate hydration levels, which may arise from a transformation tied to framework flexibility previously observed in zeolite A via gas absorption calorimetry. Values of the standard thermodynamic functions Cp,m°, Δ0TSm°, Δ0THm°, andΦm° are also reported.

Mechanistic insights into the crystallization of coamorphous drug systems.

In our previous study, the coamorphous formulation of lurasidone hydrochloride (LH) with saccharin (SAC) showed significantly enhanced dissolution and physical stability compared to crystalline/amorphous LH. However, the coamorphous system is still in amorphous state, and has the tendency to recrystallization, which will in turn result in the loss of above advantages. In this study, the crystallization kinetics under isothermal and non-isothermal conditions was investigated. Compared to amorphous LH, coamorphous LH-SAC showed 68.3-361.2 and 2.6-6.1 times lower crystallization rates in glassy state and supercooled liquid state, respectively. After co-amorphization, the addition of SAC changed the crystallization mechanism of amorphous LH from nucleation-controlled to diffusion-controlled manner. Amorphous LH followed the site-saturated nucleation, whereas the coamorphous system exhibited a fixed number of nuclei. The non-isothermal crystallization indicated amorphous LH and coamorphous LH-SAC showed two-dimensional (JMAEK 2) and three-dimensional (JMAEK 3) growth of nuclei, respectively. Furthermore, coamorphous LH-SAC exhibited higher molecular mobility and dynamic fragility (mD) than amorphous LH, which is kinetically unfavorable for its physical stability. However, from thermodynamic perspective, coamorphous LH-SAC had a higher configurational entropy, i.e., a higher entropy barrier for crystallization, which is beneficial to hinder its crystallization. Therefore, it was concluded that the higher configurational entropy rather than the molecular mobility was proposed to be responsible for its improved stability. In addition, molecular dynamics simulations with miscibility, radial distribution function and binding energy calculations suggested coamorphous components exhibited good miscibility and strong intermolecular interactions, which was also conductive to the enhancement in its stability. This study offers an in-depth understanding about the effect of the coformer on the crystallization kinetics of coamorphous systems, and points out the important contribution of the configurational entropy in stabilizing the coamorphous systems.

Performance comparation of MEA and EDA in electrochemically-mediated amine regeneration for CO2 capture

Electrochemically-mediated amine regeneration (EMAR) for CO2 capture was recently developed as a promising substitute for conventional amine-based CO2 capture by avoiding the amine thermal regeneration process. A suitable solvent is significant for the overall performance and the scale-up of the EMAR system. However, there is currently a lack of comprehensive solvent comparison methods. In this work, a systematic comparison was conducted to elucidate the absorption and desorption behavior of the most discussed monoethanolamine (MEA) and ethylenediamine (EDA) in the EMAR process. Firstly, the CO2 absorption performance was compared by considering the CO2 absorption capacity, absorption rate, and coordination ability separately. Subsequently, the performance of absorbents was compared from the perspective of thermodynamics. Results indicated that the complex of Cu(II)-EDA shows higher stability which means it is more competitive than MEA in releasing the absorbed CO2 in the EMAR process. Then, the electrochemical behaviors comparison of MEA and EDA shows that the electrochemical reactions in EDA solvent are simpler and easier to occur, but the poor diffusion performance of reactive ions in EDA hinders its scale-up application. Finally, the CO2 desorption performance in MEA and EDA was carefully studied. A competitive and practically instructive desorption energy consumption of 42.4 kJe/mol CO2 with 300 A/m2 current density was obtained in EDA solvent. Overall, compared with MEA, EDA is more recommended to be used as an absorbent in the EMAR system.

Thermodynamic Phase Transition of Generalized Ayon-Beato Garcia Black Holes

In this work, we study thermodynamics of generalized Ayon-Beato and Garcia (ABG) black hole metric which contains three parameters named as mass m , magnetic charge q , and dimensionless coupling constant of nonlinear electrodynamics interacting field γ . We showed that central regions of this black hole behaves as dS (AdS) vacuum space by setting q < 2 m q > 2 m and in the case q = 2 m reaches to a flat Minkowski space. In the large distances, this black hole behaves as a Reissner-Nordstrom BH. However, an important role of the charge q appeared in the production of a formal variable cosmological parameter which will support pressure coordinate in the thermodynamic perspective of this black hole in our setup. We should point that this formal variable cosmological parameter is different with cosmological constant which comes from AdS/CFT correspondence, and it is effective at large distances as AdS space pressure. In our setup, the assumed pressure originated from the internal material of the black hole say q and m here. By calculating the Hawking temperature of this black hole, we obtain equation of state. Then, we plotted isothermal P-V curves and heat capacity at constant pressure. They show that the system participates in the small to large phase transition of the black hole or the Hawking-Page phase transition which is similar to the van der Waals phase transition in the ordinary thermodynamics systems. In fact in the Hawking-Page phase transition disequilibrium, evaporating generalized ABG black hole reaches to a vacuum AdS space finally.

Thermodynamic characterization of LF, H, and mineral soil layers from oak forest ecosystems: Exploring the role of proximate analysis

Studying the thermodynamic properties of soil organic matter is a developing field that involves the measurement of the energy stored by the soil. Quantifying soil energy content is still challenging despite different methodological approaches are available to calculate that value. One of the options is the proximate analysis following the guidelines for the energetic characterization of biomass. However, proximate analyses are still unexplored for soils. In this paper, we investigate the potential of this analysis to contribute to study soil from a thermodynamic perspective. With that goal, 31 soil samples collected in mature oak forests following a depth transect were used for elemental, thermal and proximate analysis. Proximate analyses and energetic characterization were performed by simultaneous thermogravimetry and differential scanning calorimetry.These methods allowed fragmentation of the soil organic matter in water content, volatile matter, fixed carbon, and ash, as well as the quantification of the soil organic matter and energy content. Pearson's correlation showed significant relations among the proximate, the elemental components of soils and the energy. The equations relating all of these variables were calculated for soils from oak forests by partial least squares analysis. Equations representing the relationship between energy and the proximate fractions provide an additional alternative to calculate the heat of combustion of the soil organic matter. This value is the essential step for the thermodynamic characterization of soils.

A numerical model for hydrothermal transport in unsaturated freezing soils considering thermodynamics equilibrium

AbstractThe analysis of frost heave in unsaturated subgrade soils should consider the coupled movement of liquid water, vapor, and heat, accompanied by phase transition of water, vapor, and ice. In this paper, the equilibrium relationship of the three phases of water in soils was comprehensively considered, and the water head and vapor density were determined under frozen and unfrozen conditions from the perspective of thermodynamics. Based on that, the governing equations of mass and energy conservation were then derived and a new transient finite element model was developed, considering the behavior of the phase change and coupled hydrothermal transport under frozen as well as unfrozen conditions. Since the discontinuities between the frozen and the unfrozen zones may bring difficulties to the numerical solution, two kinds of smoothing techniques were proposed to solve the discontinuities at the phase transition interface, which guaranteed robust convergence and enhanced computational efficiency. The model proposed was verified by comparing with some available test results and applied to analyze the frost heave process of unsaturated subgrade under impermeable road pavements, demonstrating the model's accuracy and applicative prospect. It is revealed that the movement of liquid water and vapor in the frozen zones may still exist, and its mechanism and performance are different from that in unfrozen zones. The significance of vapor migration on the subgrade frost heave is also emphasized.

Adsorption of Molnupiravir anti-COVID-19 drug over B12N12 and Al12N12 nanocarriers: a DFT study

The potentiality of B12N12 and Al12N12 nanocarriers to adsorb Molnupiravir anti-COVID-19 drug, for the first time, was herein elucidated using a series of quantum mechanical calculations. Density function theory (DFT) was systematically utilized. Interaction (E int) and adsorption (E ads) energies showed higher negative values for Molnupiravir···Al12N12 complexes compared with Molnupiravir···B12N12 analogs. Symmetry-adapted perturbation theory (SAPT) results proclaimed that the adsorption process was predominated by electrostatic forces. Notably, the alterations in the distributions of the molecular orbitals ensured that the B12N12 and Al12N12 nanocarriers were efficient candidates for delivering the Molnupiravir drug. From the thermodynamic perspective, the adsorption process of Molnupiravir drug over B12N12 and Al12N12 nanocarriers had spontaneous and exothermic nature. The ESP, QTAIM, NCI, and DOS observations exposed the tendency of BN and Al12N12 to adsorb the Molnupiravir drug. Overall, these findings proposed that the B12N12 and Al12N12 nanocarriers are efficient aspirants for the development of the Molnupiravir anti-COVID-19 drug delivery process. Communicated by Ramaswamy H. Sarma

Thermodynamic analysis of a novel hybrid fuel cell-combined cooling, heating-and power (CCHP) system-integrated solar-driven biomass gasification for achieving sustainable and efficient poly-generation

ABSTRACT In this work, a novel biomass and solar energy hybrid fuel cell-combined cooling, heating, and power (CCHP) system is proposed, including solar-driven biomass gasification, solid oxide fuel cell, homogeneous charge compression ignition engine, double-effect absorption chiller, and waste heat recovery unit. The aim of this work is to explore the feasibility of the proposed system from thermodynamic and environmental perspectives. Based on the thermodynamic modeling, the comprehensive performance of the proposed system is evaluated by multiple methods, including energy, exergy, exergoeconomic, and environmental analyses. Furthermore, it was compared with a reference system without solar energy to illustrate the advantages of the proposed system. It is found that the total energy and exergy efficiency of the hybrid system are 57.5% and 36.6% under design condition, respectively. The energy and exergy efficiency of the proposed system are 2.7% and 2.1% higher than those of the reference system, respectively. The introduction of solar energy significantly increases the utilization rate and the generating capacity of the unit biomass by 63.8% and 36.3%, respectively, compared to the reference system. In addition, the carbon emission of the proposed system is about 0.071 to 0.075 t/GJ and 46.3% lower than that of the reference system.