Based on improved immune algorithm, the location of material storage in manufacturing workshop is studied. Intelligent optimization algorithms include particle swarm optimization algorithm, genetic selection algorithm...Based on improved immune algorithm, the location of material storage in manufacturing workshop is studied. Intelligent optimization algorithms include particle swarm optimization algorithm, genetic selection algorithm, simulated annealing algorithm, tabu search algorithm and so on. According to the non-linear constraints, the objective function is established to solve the minimum energy consumption of material distribution. The improved immune algorithm can solve the complex problem of manufacturing workshop, and the material storage location and scheduling scheme can be obtained by combining simulation software. Scheduling optimization involves material warehousing, sorting, loading and unloading, handling and so on. Using the one-to-one accurate distribution principle and MATLAB software to simulate and analyze, the location of material warehousing in manufacturing workshop is determined, and the material distribution and scheduling are studied.展开更多
With the development of the times, the development of the petrochemical industry in our country has gradually made great progress, which has a great impact on the cost, utilization and economic benefits of enterprise ...With the development of the times, the development of the petrochemical industry in our country has gradually made great progress, which has a great impact on the cost, utilization and economic benefits of enterprise materials. The material storage management of petrochemical enterprises is closely related to the competitiveness and position of the enterprises in the market. However, there are still many deficiencies in the material storage management of some enterprises. In this regard, this paper explores the management mode of material storage in petrochemical enterprises, analyzes the problems existing in the management of material storage and puts forward solutions to solve the problems encountered in the management.展开更多
While early transition metal-based materials,such as MXene,has emerged as an efficient catalyst for the Mg-based hydrogen storage materials,their strong interaction with hydrogen resulted in the high hydrogen diffusio...While early transition metal-based materials,such as MXene,has emerged as an efficient catalyst for the Mg-based hydrogen storage materials,their strong interaction with hydrogen resulted in the high hydrogen diffusion barrier,hindering further improvement of catalytic activity.A MXene is characterized by rich anionic groups on its surface,significantly affecting electronic and catalytic functionalities.Using Nb_(2)CT_(x)as an example,we herein illustrate the critical role of anionic T_(x)defects on controlling hydrogen dissociation and diffusion processes in Mg-based hydrogen storage materials.The hydrogen desorption properties of MgH_(2)can be significantly enhanced by utilizing T_(x)controllable Nb_(2)CT_(x),and it can release 3.57 wt.%hydrogen within 10 min under 240℃with the reduced dehydrogenation activation barrier.It also realized stable de/hydrogenation reactions for at least 50 cycles.DFT studies combined with kinetic analysis revealed that the catalyst‒hydrogen interaction could be systematically controlled by optimizing surface T_(x)defect density,accelerating the hydrogen dissociation and diffusion processes at the same time.These results demonstrate that the T_(x)defects serve as the effective catalytically active centers of Nb_(2)CT_(x),offering a flexible catalyst design guideline.展开更多
In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integra...In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integrated with phase change material(PCM)thermal storage is proposed.First,a thermal energy management framework is constructed,combining PCM thermal storage with the alkaline electrolyzer(AE)waste heat recovery and the heat pump(HP),while establishing a PCM-driven waste drying system to enhance the efficiency of waste incineration power generation.Next,a flue gas treatment method based on purification-separation-storage coordination is adopted,achieving spatiotemporal decoupling between waste incineration and flue gas treatment.Subsequently,a two-stage optimal dispatching strategy for the multi-energy system is developed:the first stage establishes a dayahead economic dispatch model with the objective of minimizing net system costs,while the second stage introduces model predictive control(MPC)to realize intraday rolling optimization.Finally,The optimal dispatching strategies under different scenarios are obtained using the Gurobi solver,followed by a comparative analysis of the optimized operational outcomes.Simulation results demonstrate that the proposed system optimizes the output and operational states of each unit,simultaneously reducing carbon trading costs while increasing electricity sales revenue.The proposed scheduling strategy demonstrates effective grid peak-shaving functionality,thereby simultaneously improving the system’s economic performance and operational flexibility while providing an innovative technical pathway for municipal solid waste(MSW)resource utilization and low-carbon transformation of energy systems.展开更多
So far,a clear understanding about the relationship of variable energy band structure with the corresponding charge-discharge process of energy storage materials is still lacking.Here,using optical spectroscopy(red-gr...So far,a clear understanding about the relationship of variable energy band structure with the corresponding charge-discharge process of energy storage materials is still lacking.Here,using optical spectroscopy(red-green-blue(RGB)value,reflectivity,transmittance,UV-vis,XPS,UPS)to studyα-Co(OH)_(2) electrode working in KOH electrolyte as the research object,we provide direct experimental evidence that:(1)The intercalation of OH-ions will reduce the valence/conduction band(VB and CB)and band gap energy(Eg)values;(2)The deintercalation of OH-ions corresponds with the reversion of VB,CB and E_(g) to the initial values;(3)The color of Co(OH)_(2) electrode also exhibit regular variations in RGB value during the charge-discharge process.展开更多
As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather tha...As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather than H_(2)upon decomposition.In this work,we report thatthe combination of AlH_(3)and LiNH_(2)through simple ball milling leads to partial reversibility of the AlH_(3)-LiNH_(2)system and the suppression of NH_(3)liberation.The negatively charged H^(δ-)in AlH_(3)will react with the positively charged H^(δ+)in LiNH_(2)through a redox reaction to form Li_(2)NH,AlN,and H_(2)at 120-170℃.After dehydrogenation at above 270℃,Li_(3)AlN_(2)is generated,which is crucial for the reversibility of this system.The more the Li3AlN2generated,the better the reversibility of this system.The dehydrogenation capacity of AlH_(3)+2LiNH_(2)at the third cycle(3.0 wt%)is higher than that of AlH_(3)+LiNH_(2)(1.2 wt%)due to the generation of more Li3AlN2.The role of AIH_(3)/Al in the AlH_(3)-LiNH_(2)system is to fix the nitrogen into the form of AIN and Li_(3)AlN_(2)and thus suppress the liberation of NH_(3).Therefore,the synergy of AlH_(3)and LiNH_(2)leads to the reversibility of the Li-Al-NH system and the suppression of NH_(3).展开更多
Azobenzene and its derivatives are the most extensively investigated and applied molecular photoswitches,which can undergo reversible transformation between trans and cis isomers upon irradiation with light at specifi...Azobenzene and its derivatives are the most extensively investigated and applied molecular photoswitches,which can undergo reversible transformation between trans and cis isomers upon irradiation with light at specific wavelengths.Through structural geometry transformation,the property alterations can be integrated into smart materials to meet diverse application requirements.Most azo-based photo-switches require UV light for activation.However,complete activation within the visible or even near-infrared light range could offer several benefits for photo-switch applications,including improved biocompatibility,better light penetration,and enhanced solar light utilization efficiency.This review presents an overview of the development of visible-light responsive azo-based materials,covering molec-ular design strategies and their applications in energy storage.Recent efforts aimed at enhancing the performance of azo-based energy storage materials are high-lighted.According to the different strategies for improving energy storage prop-erties,these materials are categorized as those that directly increase isomerization energy and those that introduce phase transition energy.Furthermore,we discuss the challenges and opportunities in this field with a view to inspire further exploration.展开更多
High-efficiency solar energy systems are characterized by their designs,which primarily rely on effective concentration and conversion methods of solar radiation.Evaluation of the performance enhancement of flat plate...High-efficiency solar energy systems are characterized by their designs,which primarily rely on effective concentration and conversion methods of solar radiation.Evaluation of the performance enhancement of flat plate solar collectors by integration with thermal energy storage could be achieved through simulation of proposed designs.The work aims to analyze a new solar collector integrated with a porous medium and shell and coiled tube heat exchanger.The heat transfer enhancement was investigated by varying the geometrical parameters in shell and helically coiled tubes operating with CuFe_(2)O_(4)/water with different volume fractions of 0.02%,0.05%,and 0.1 vol.%.This study presents an experimental and numerical investigation of the performance of the flat plate solar collector integrated with a helical coil heat exchanger using nanofluids.The solar collector has a dimension of 180 cm×80 cm and works with close-loop systems operated by the thermo siphon method.Two types of helical coil heat exchangers,Coil-A and Coil-B have been investigated.The diameter of the glass porous media was investigated at 2,5,and 10 mm.The results manifested that the enhancement in the Nusselt number of the nanofluid reached maximum values of 15%,18%,and 22%for nanofluid ferrofluid with volume concentrations of 0.02%,0.05%,and 0.1%,respectively,for Coil-A.The maximum values of Nusselt number enhancement were 14%,17%,and 20%for ferrofluid concentrations of 0.02%,0.05%,and 0.1 vol.%,respectively,for Coil-B.The results also elucidated that the nanofluid mass flow and heat transfer rates could be noticeably compared to water.Where the increase is 5%,10%,and 20%for each concentration and diameter of the porous media,it specifies the enormous ranges of operational and geometrical parameters.展开更多
Owing to the orbital hybridization between the transition metal and the B element and the electron-trapping effect of the B ele-ment,transition metal borides are considered very promising materials for energy catalysi...Owing to the orbital hybridization between the transition metal and the B element and the electron-trapping effect of the B ele-ment,transition metal borides are considered very promising materials for energy catalysis.In this work,an amorphous scaly high-entropy boride(HEB)with electron traps was designed and fabricated via a facile reduction method to improve the hydrogen storage properties of magnesium hydride(MgH_(2)).For dehydrogenation,the onset temperature of MgH_(2)+10wt%HEB was dropped to 187.4℃;be-sides,the composite exhibited superior isothermal kinetics and the activation energy of the composite was reduced from(212.78±3.93)to(65.04±2.81)kJ/mol.In addition,MgH_(2)+10wt%HEB could absorb hydrogen at 21.5℃,and 5.02wt%H_(2) was charged in 50 min at 75℃.For reversible hydrogen storage capacity tests,the composite maintained a retention rate of 97%with 6.47wt%hydrogen capacity after 30 cycles.Combining microstructure evidence with hydrogen storage performance,the catalytic mechanism was proposed.During ball milling,scaly high-entropy borides riveted a large number of heterogeneous active sites on the surface of MgH_(2).Driven by the cocktail effect as well as the orbital hybridization of metal borides,numerous active sites steadily enhanced the hydrogen storage reactions in MgH_(2).展开更多
The high operating temperatures and slow kinetics limit the application of MgH_(2)-based hydrogen storage materials.Here,a composite of Ni_(3)ZnC_(0.7)/carbon nanotubes loaded onto a melamine sponge-derived carbon(MS)...The high operating temperatures and slow kinetics limit the application of MgH_(2)-based hydrogen storage materials.Here,a composite of Ni_(3)ZnC_(0.7)/carbon nanotubes loaded onto a melamine sponge-derived carbon(MS)skeleton is prepared and loaded onto MgH_(2).During dehydrogenation,Ni_(3)ZnC_(0.7)reacts with MgH_(2)and in situ changes to Mg_(2)Ni/Zn.The transformation of Mg_(2)Ni/Mg_(2)NiH_(4) serves as a“hydrogen pump”,providing diffusion channels for hydrogen atoms and molecules to promote the de-/hydrogenation processes.Moreover,Zn/MgZn_(2) provides the catalytic sites for the transformation of Mg/MgH_(2).The length of the Mg-H bond is elongated from 1.72 to 1.995Å,and the dissociation energy barrier of MgH_(2)is reduced from 1.55 to 0.49 eV.As a result,MgH_(2)with 2.5 wt%MS@Ni_(3)ZnC_(0.7)can absorb 5.18 wt%H_(2)at 423 K within 200 s,and its initial dehydrogenation temperature is reduced to 585 K.After 20 cycles,the dehydrogenation capacity retention is determined to be 94.6%.This work demonstrates an efficient non-stoichiometric metal carbide catalyst for MgH_(2).展开更多
As a typical reactive composite hydrogen storage system,2LiBH_(4)-MgH_(2)holds an ultrahigh hydrogen storage capacity of 11.5 wt%.However,it suffers from sluggish hydrogen storage kinetics due to the difficult nucleat...As a typical reactive composite hydrogen storage system,2LiBH_(4)-MgH_(2)holds an ultrahigh hydrogen storage capacity of 11.5 wt%.However,it suffers from sluggish hydrogen storage kinetics due to the difficult nucleation of MgB_(2).Herein,amorphous VB_(2)nanoparticles with an average size of approximately 32 nm are synthesized to enhance the hydrogen storage performance of 2LiBH_(4)-MgH_(2)composite.VB_(2),sharing the same hexagonal structure with MgB_(2)with a d-value mismatch ratio of only 2.28%,could serve as effective nucleation sites for promoting the formation of MgB_(2).Theoretical calculations reveal that the introduction of VB_(2)significantly reduces the binding energies of B and Mg,facilitating in situ nucleation of MgB_(2).As a result,after the introduction of VB_(2)nanoparticles,complete hydrogen desorption of 9.23 wt%is achieved for 2LiBH_(4)-MgH_(2)within 2 h at 400℃,which is 4 times shorter than the time required for pure 2LiBH_(4)-MgH_(2),and no nucleation incubation period for hydrogen desorption is observed even at a low temperature of380℃.More importantly,a reversible capacity of9.3 wt%,corresponding to a capacity retention of 100%,could be preserved after 10 cycles of hydrogen storage,demonstrating stable reversible hydrogen storage performance.This study provides a novel technological pathway for improving the reversible hydrogen storage performance of composite metal hydrides and offers significant insights into the development of high-performance hydrogen storage materials.展开更多
Mg-based materials are one of the most promising hydrogen storage candidates due to their high hydrogen storage capacity,environmental benignity,and high Clarke number characteristics.However,the limited thermodynamic...Mg-based materials are one of the most promising hydrogen storage candidates due to their high hydrogen storage capacity,environmental benignity,and high Clarke number characteristics.However,the limited thermodynamics and kinetic properties pose major challenges for their engineering applications.Herein,we review the recent progress in improving their thermodynamics and kinetics,with an emphasis on the models and the influence of various parameters in the calculated models.Subsequently,the impact of alloying,composite,and nanocrystallization on both thermodynamics and dynamics are discussed in detail.In particular,the correlation between various modification strategies and the hydrogen capacity,dehydrogenation enthalpy and temperature,hydriding/dehydriding rates are summarized.In addition,the mechanism of hydrogen storage processes of Mg-based materials is discussed from the aspect of classical kinetic theories and microscope hydrogen transferring behavior.This review concludes with an outlook on the remaining challenge issues and prospects.展开更多
With the depletion of fossil fuels and global warming,there is an urgent demand to seek green,low-cost,and high-efficiency energy resources.Hydrogen has been considered as a potential candidate to replace fossil fuels...With the depletion of fossil fuels and global warming,there is an urgent demand to seek green,low-cost,and high-efficiency energy resources.Hydrogen has been considered as a potential candidate to replace fossil fuels,due to its high gravimetric energy density(142 MJ kg^(-1)),high abundance(H_(2)O),and environmentalfriendliness.However,due to its low volume density,effective and safe hydrogen storage techniques are now becoming the bottleneck for the"hydrogen economy".Under such a circumstance,Mg-based hydrogen storage materials garnered tremendous interests due to their high hydrogen storage capacity(~7.6 wt%for MgH_(2)),low cost,and excellent reversibility.However,the high thermodynamic stability(ΔH=-74.7 kJ mol^(-1)H_(2))and sluggish kinetics result in a relatively high desorption temperature(>300℃),which severely restricts widespread applications of MgH_(2).Nano-structuring has been proven to be an effective strategy that can simultaneously enhance the ab/de-sorption thermodynamic and kinetic properties of MgH_(2),possibly meeting the demand for rapid hydrogen desorption,economic viability,and effective thermal management in practical applications.Herein,the fundamental theories,recent advances,and practical applications of the nanostructured Mg-based hydrogen storage materials are discussed.The synthetic strategies are classified into four categories:free-standing nano-sized Mg/MgH_(2)through electrochemical/vapor-transport/ultrasonic methods,nanostructured Mg-based composites via mechanical milling methods,construction of core-shell nano-structured Mg-based composites by chemical reduction approaches,and multi-dimensional nano-sized Mg-based heterostructure by nanoconfinement strategy.Through applying these strategies,near room temperature ab/de-sorption(<100℃)with considerable high capacity(>6 wt%)has been achieved in nano Mg/MgH_(2)systems.Some perspectives on the future research and development of nanostructured hydrogen storage materials are also provided.展开更多
Over the last decade’s magnesium and magnesium based compounds have been intensively investigated as potential hydrogen storage as well as thermal energy storage materials due to their abundance and availability as w...Over the last decade’s magnesium and magnesium based compounds have been intensively investigated as potential hydrogen storage as well as thermal energy storage materials due to their abundance and availability as well as their extraordinary high gravimetric and volumetric storage densities.This review work provides a broad overview of the most appealing systems and of their hydrogenation/dehydrogenation properties.Special emphasis is placed on reviewing the efforts made by the scientific community in improving the material’s thermodynamic and kinetic properties while maintaining a high hydrogen storage capacity.展开更多
Mg-based materials have been intensively studied for hydrogen storage applications due to their high energy density up to 2600 Wh/kg or 3700 Wh/L.However,the Mg-based materials with poor kinetics and the necessity for...Mg-based materials have been intensively studied for hydrogen storage applications due to their high energy density up to 2600 Wh/kg or 3700 Wh/L.However,the Mg-based materials with poor kinetics and the necessity for a high temperature to achieve 0.1 MPa hydrogen equilibrium pressure limit the applications in the onboard storage in Fuel cell vehicles(FCVs).Over the past decades,many methods have been applied to improve the hydriding/dehydriding(H/D)kinetics of Mg/MgH 2 by forming amorphous or nanosized particles,adding catalysts and employing external energy field,etc.However,which method is more effective and the intrinsic mechanism they work are widely differing versions.The hydrogenation and dehydrogenation behaviors of Mg-based alloys analyzing by kinetic models is an efficient way to reveal the H/D kinetic mechanism.However,some recently proposed models with physical meaning and simple analysis method are not known intimately by researchers.Therefore,this review focuses on the enhancement method of kinetics in Mg-based hydrogen storage materials and introduces the new kinetic models.展开更多
Magnesium hydride(MgH_(2)) is a candidate material for hydrogen storage.MgH_(2)-AlH_(3) composite shows superior hydrogen desorption properties than pure MgH_(2).However,this composite still suffers from poor cycling ...Magnesium hydride(MgH_(2)) is a candidate material for hydrogen storage.MgH_(2)-AlH_(3) composite shows superior hydrogen desorption properties than pure MgH_(2).However,this composite still suffers from poor cycling performance.In this work,NbF_(5) was utilized to improve the cycling properties of the MgH_(2)-AlH_(3) composite.Cycling hydrogen desorption studies show that NbF_(5) significantly improves the cycling stability of MgH_(2)-AlH_(3).The MgH_(2)-AlH_(3)-NbF_(5) composite can release about 2.7 wt% of hydrogen at 300℃ for 1 h and the hydrogen desorption capacity can maintain at 2.7 wt% for more than100 cycles.In comparison,the hydrogen desorption capacity of the MgH_(2)-AlH_(3) composite is decreasing with the cycle number increasing.The capacity is reduced from a maximum value of 3.3 wt% to about 1.0 wt% after 40 cycles.Brunauer-Emmett-Teller(BET) surface area measurements show that the particle size of MgH_(2)-AlH_(3) composite decreases after cycling,which means pulverization of the composite.NbF_(5) can to some extent suppress the pulverization of the composite during cycling,which partially contributes to the improvement of the cycling hydrogen desorption properties of the material.展开更多
Supercapacitors are favorable energy storage devices in the field of emerging energy technologies with high power density,excellent cycle stability and environmental benignity.The performance of supercapacitors is def...Supercapacitors are favorable energy storage devices in the field of emerging energy technologies with high power density,excellent cycle stability and environmental benignity.The performance of supercapacitors is definitively influenced by the electrode materials.Nickel sulfides have attracted extensive interest in recent years due to their specific merits for supercapacitor application.However,the distribution of electrochemically active sites critically limits their electrochemical performance.Notable improvements have been achieved through various strategies such as building synergetic structures with conductive substrates,enhancing the active sites by nanocrystallization and constructing nanohybrid architecture with other electrode materials.This article overviews the progress in the reasonable design and preparation of nickel sulfides and their composite electrodes combined with various bifunctional electric double-layer capacitor(EDLC)-based substances(e.g.,graphene,hollow carbon)and pseudocapacitive materials(e.g.,transition-metal oxides,sulfides,nitrides).Moreover,the corresponding electrochemical performances,reaction mechanisms,emerging challenges and future perspectives are briefly discussed and summarized.展开更多
Rechargeable batteries and supercapacitors are widely investigated as the most important electrochemical energy storage devices nowadays due to the booming energy demand for electric vehicles and hand-held electronics...Rechargeable batteries and supercapacitors are widely investigated as the most important electrochemical energy storage devices nowadays due to the booming energy demand for electric vehicles and hand-held electronics. The large surface-area-to-volume ratio and internal surface areas endow two-dimensional（2D） materials with high mobility and high energy density; therefore, 2D materials are very promising candidates for Li ion batteries and supercapacitors with comprehensive investigations. In 2011, a new kind of 2D transition metal carbides, nitrides and carbonitrides, MXene, were successfully obtained from MAX phases. Since then about 20 different kinds of MXene have been prepared. Other precursors besides MAX phases and even other methods such as chemical vapor deposition（CVD） were also applied to prepare MXene, opening new doors for the preparation of new MXene. Their 2D nature and good electronic properties ensure the inherent advantages as electrode materials for electrochemical energy storage. In this review, we summarize the recent progress in the development of MXene with emphasis on the applications to electrochemical energy storage. Also, future perspective and challenges of MXene-based materials are briefly discussed regrading electrochemical energy storage.展开更多
A SnO-graphite composite material, which can deliver high capacities and good cycling stability compared with unsupported SnO, was described. This material prepared via chemical co-precipitation reaction in the presen...A SnO-graphite composite material, which can deliver high capacities and good cycling stability compared with unsupported SnO, was described. This material prepared via chemical co-precipitation reaction in the presence of graphite consists of high dispersion of SnO with a size of about several hundred nanometers in the graphite. The phase structure was analyzed by X-ray diffraction (XRD). The morphology and the element distribution were examined by scanning electron microscopy (SEM) equipped with energy spectrum. The results show that the SnO-graphite composites produced by slowly hydrolysis have higher rechargeable capacities than pure graphite and better cycling performance than SnO.展开更多
The thermal energy storage phase change material used for building has been prepared with a few of fatty acids based on the principle of binary low eutectic point. The thermal behaviors such as phase transition temper...The thermal energy storage phase change material used for building has been prepared with a few of fatty acids based on the principle of binary low eutectic point. The thermal behaviors such as phase transition temperature and enthalpy of compound energy storage material are researched through differential scanning calorimeter(DSC) and scanning electron microscope(SEM) . The results show that the thermal energy storage phase change composite material can be used in the wall panels well as its higher latent heat.展开更多
文摘Based on improved immune algorithm, the location of material storage in manufacturing workshop is studied. Intelligent optimization algorithms include particle swarm optimization algorithm, genetic selection algorithm, simulated annealing algorithm, tabu search algorithm and so on. According to the non-linear constraints, the objective function is established to solve the minimum energy consumption of material distribution. The improved immune algorithm can solve the complex problem of manufacturing workshop, and the material storage location and scheduling scheme can be obtained by combining simulation software. Scheduling optimization involves material warehousing, sorting, loading and unloading, handling and so on. Using the one-to-one accurate distribution principle and MATLAB software to simulate and analyze, the location of material warehousing in manufacturing workshop is determined, and the material distribution and scheduling are studied.
文摘With the development of the times, the development of the petrochemical industry in our country has gradually made great progress, which has a great impact on the cost, utilization and economic benefits of enterprise materials. The material storage management of petrochemical enterprises is closely related to the competitiveness and position of the enterprises in the market. However, there are still many deficiencies in the material storage management of some enterprises. In this regard, this paper explores the management mode of material storage in petrochemical enterprises, analyzes the problems existing in the management of material storage and puts forward solutions to solve the problems encountered in the management.
基金supported by Liuchuang Program of Chongqing Municipality(cx2022038)the Fundamental Research Funds for the Central Universities(2022CDJQY-013)the Graduate Research and Innovation Foundation of Chongqing,China(CYB22005).
文摘While early transition metal-based materials,such as MXene,has emerged as an efficient catalyst for the Mg-based hydrogen storage materials,their strong interaction with hydrogen resulted in the high hydrogen diffusion barrier,hindering further improvement of catalytic activity.A MXene is characterized by rich anionic groups on its surface,significantly affecting electronic and catalytic functionalities.Using Nb_(2)CT_(x)as an example,we herein illustrate the critical role of anionic T_(x)defects on controlling hydrogen dissociation and diffusion processes in Mg-based hydrogen storage materials.The hydrogen desorption properties of MgH_(2)can be significantly enhanced by utilizing T_(x)controllable Nb_(2)CT_(x),and it can release 3.57 wt.%hydrogen within 10 min under 240℃with the reduced dehydrogenation activation barrier.It also realized stable de/hydrogenation reactions for at least 50 cycles.DFT studies combined with kinetic analysis revealed that the catalyst‒hydrogen interaction could be systematically controlled by optimizing surface T_(x)defect density,accelerating the hydrogen dissociation and diffusion processes at the same time.These results demonstrate that the T_(x)defects serve as the effective catalytically active centers of Nb_(2)CT_(x),offering a flexible catalyst design guideline.
文摘In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integrated with phase change material(PCM)thermal storage is proposed.First,a thermal energy management framework is constructed,combining PCM thermal storage with the alkaline electrolyzer(AE)waste heat recovery and the heat pump(HP),while establishing a PCM-driven waste drying system to enhance the efficiency of waste incineration power generation.Next,a flue gas treatment method based on purification-separation-storage coordination is adopted,achieving spatiotemporal decoupling between waste incineration and flue gas treatment.Subsequently,a two-stage optimal dispatching strategy for the multi-energy system is developed:the first stage establishes a dayahead economic dispatch model with the objective of minimizing net system costs,while the second stage introduces model predictive control(MPC)to realize intraday rolling optimization.Finally,The optimal dispatching strategies under different scenarios are obtained using the Gurobi solver,followed by a comparative analysis of the optimized operational outcomes.Simulation results demonstrate that the proposed system optimizes the output and operational states of each unit,simultaneously reducing carbon trading costs while increasing electricity sales revenue.The proposed scheduling strategy demonstrates effective grid peak-shaving functionality,thereby simultaneously improving the system’s economic performance and operational flexibility while providing an innovative technical pathway for municipal solid waste(MSW)resource utilization and low-carbon transformation of energy systems.
基金supported by the National Natural Science Foundation of China(Nos.51972146,52072150).
文摘So far,a clear understanding about the relationship of variable energy band structure with the corresponding charge-discharge process of energy storage materials is still lacking.Here,using optical spectroscopy(red-green-blue(RGB)value,reflectivity,transmittance,UV-vis,XPS,UPS)to studyα-Co(OH)_(2) electrode working in KOH electrolyte as the research object,we provide direct experimental evidence that:(1)The intercalation of OH-ions will reduce the valence/conduction band(VB and CB)and band gap energy(Eg)values;(2)The deintercalation of OH-ions corresponds with the reversion of VB,CB and E_(g) to the initial values;(3)The color of Co(OH)_(2) electrode also exhibit regular variations in RGB value during the charge-discharge process.
基金financially supported by the National Natural Science Foundation of China(Nos.22379030,52001079,52261038)the Science and Technology Department of Guangxi Zhuang Autonomous(Nos.2024JJG160001,GuiKeAD21238022)the Innovation Project of Guangxi Graduate Education(No.YCBZ2023011)
文摘As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather than H_(2)upon decomposition.In this work,we report thatthe combination of AlH_(3)and LiNH_(2)through simple ball milling leads to partial reversibility of the AlH_(3)-LiNH_(2)system and the suppression of NH_(3)liberation.The negatively charged H^(δ-)in AlH_(3)will react with the positively charged H^(δ+)in LiNH_(2)through a redox reaction to form Li_(2)NH,AlN,and H_(2)at 120-170℃.After dehydrogenation at above 270℃,Li_(3)AlN_(2)is generated,which is crucial for the reversibility of this system.The more the Li3AlN2generated,the better the reversibility of this system.The dehydrogenation capacity of AlH_(3)+2LiNH_(2)at the third cycle(3.0 wt%)is higher than that of AlH_(3)+LiNH_(2)(1.2 wt%)due to the generation of more Li3AlN2.The role of AIH_(3)/Al in the AlH_(3)-LiNH_(2)system is to fix the nitrogen into the form of AIN and Li_(3)AlN_(2)and thus suppress the liberation of NH_(3).Therefore,the synergy of AlH_(3)and LiNH_(2)leads to the reversibility of the Li-Al-NH system and the suppression of NH_(3).
基金National Natural Science Foundation of China(22108026,22178050)the Young Elite Scientists Sponsorship Program by CAST(2021QNRC001)+2 种基金the Natural Science Foundation of Liaoning Province(2022-BS-091)the Dalian Science and Technology Innovation Fund Young Tech Star(2022RQ008)the Fundamental Research Funds for the Central Universities(DUT22LAB610).
文摘Azobenzene and its derivatives are the most extensively investigated and applied molecular photoswitches,which can undergo reversible transformation between trans and cis isomers upon irradiation with light at specific wavelengths.Through structural geometry transformation,the property alterations can be integrated into smart materials to meet diverse application requirements.Most azo-based photo-switches require UV light for activation.However,complete activation within the visible or even near-infrared light range could offer several benefits for photo-switch applications,including improved biocompatibility,better light penetration,and enhanced solar light utilization efficiency.This review presents an overview of the development of visible-light responsive azo-based materials,covering molec-ular design strategies and their applications in energy storage.Recent efforts aimed at enhancing the performance of azo-based energy storage materials are high-lighted.According to the different strategies for improving energy storage prop-erties,these materials are categorized as those that directly increase isomerization energy and those that introduce phase transition energy.Furthermore,we discuss the challenges and opportunities in this field with a view to inspire further exploration.
文摘High-efficiency solar energy systems are characterized by their designs,which primarily rely on effective concentration and conversion methods of solar radiation.Evaluation of the performance enhancement of flat plate solar collectors by integration with thermal energy storage could be achieved through simulation of proposed designs.The work aims to analyze a new solar collector integrated with a porous medium and shell and coiled tube heat exchanger.The heat transfer enhancement was investigated by varying the geometrical parameters in shell and helically coiled tubes operating with CuFe_(2)O_(4)/water with different volume fractions of 0.02%,0.05%,and 0.1 vol.%.This study presents an experimental and numerical investigation of the performance of the flat plate solar collector integrated with a helical coil heat exchanger using nanofluids.The solar collector has a dimension of 180 cm×80 cm and works with close-loop systems operated by the thermo siphon method.Two types of helical coil heat exchangers,Coil-A and Coil-B have been investigated.The diameter of the glass porous media was investigated at 2,5,and 10 mm.The results manifested that the enhancement in the Nusselt number of the nanofluid reached maximum values of 15%,18%,and 22%for nanofluid ferrofluid with volume concentrations of 0.02%,0.05%,and 0.1%,respectively,for Coil-A.The maximum values of Nusselt number enhancement were 14%,17%,and 20%for ferrofluid concentrations of 0.02%,0.05%,and 0.1 vol.%,respectively,for Coil-B.The results also elucidated that the nanofluid mass flow and heat transfer rates could be noticeably compared to water.Where the increase is 5%,10%,and 20%for each concentration and diameter of the porous media,it specifies the enormous ranges of operational and geometrical parameters.
基金supported by the National Natural Science Foundation of China(No.22179054)the Jiangsu Province Innovation Support Project,China(No.BZ2023010)+1 种基金the Project of Jiangsu University High-Tech Ship Collaborative Innovation Center(No.1174871801-11)the Ministry of Science and Technology of the People’s Republic of China(No.G2023014022L).
文摘Owing to the orbital hybridization between the transition metal and the B element and the electron-trapping effect of the B ele-ment,transition metal borides are considered very promising materials for energy catalysis.In this work,an amorphous scaly high-entropy boride(HEB)with electron traps was designed and fabricated via a facile reduction method to improve the hydrogen storage properties of magnesium hydride(MgH_(2)).For dehydrogenation,the onset temperature of MgH_(2)+10wt%HEB was dropped to 187.4℃;be-sides,the composite exhibited superior isothermal kinetics and the activation energy of the composite was reduced from(212.78±3.93)to(65.04±2.81)kJ/mol.In addition,MgH_(2)+10wt%HEB could absorb hydrogen at 21.5℃,and 5.02wt%H_(2) was charged in 50 min at 75℃.For reversible hydrogen storage capacity tests,the composite maintained a retention rate of 97%with 6.47wt%hydrogen capacity after 30 cycles.Combining microstructure evidence with hydrogen storage performance,the catalytic mechanism was proposed.During ball milling,scaly high-entropy borides riveted a large number of heterogeneous active sites on the surface of MgH_(2).Driven by the cocktail effect as well as the orbital hybridization of metal borides,numerous active sites steadily enhanced the hydrogen storage reactions in MgH_(2).
基金supported by the National Natural Science Foundation of China(No.52101274)the Natural Science Foundation of Shandong Province(Nos.ZR2020QE011 and ZR2022ME089)+2 种基金Youth Top Talent Foundation of Yantai University(No.2219008)Graduate Innovation Foundation of Yantai University(No.GIFYTU2240)College Student Innovation and Entrepreneurship Training Program Project(No.202311066088).
文摘The high operating temperatures and slow kinetics limit the application of MgH_(2)-based hydrogen storage materials.Here,a composite of Ni_(3)ZnC_(0.7)/carbon nanotubes loaded onto a melamine sponge-derived carbon(MS)skeleton is prepared and loaded onto MgH_(2).During dehydrogenation,Ni_(3)ZnC_(0.7)reacts with MgH_(2)and in situ changes to Mg_(2)Ni/Zn.The transformation of Mg_(2)Ni/Mg_(2)NiH_(4) serves as a“hydrogen pump”,providing diffusion channels for hydrogen atoms and molecules to promote the de-/hydrogenation processes.Moreover,Zn/MgZn_(2) provides the catalytic sites for the transformation of Mg/MgH_(2).The length of the Mg-H bond is elongated from 1.72 to 1.995Å,and the dissociation energy barrier of MgH_(2)is reduced from 1.55 to 0.49 eV.As a result,MgH_(2)with 2.5 wt%MS@Ni_(3)ZnC_(0.7)can absorb 5.18 wt%H_(2)at 423 K within 200 s,and its initial dehydrogenation temperature is reduced to 585 K.After 20 cycles,the dehydrogenation capacity retention is determined to be 94.6%.This work demonstrates an efficient non-stoichiometric metal carbide catalyst for MgH_(2).
基金financially supported by the National Key R&D Program of China(No.2021YFB 3802400)the National Natural Science Foundation of China(Nos.U2130208,22279020 and 52301264)the Science and Technology Commission of Shanghai Municipality(Nos.23ZR1406500 and 22ZR1406500)
文摘As a typical reactive composite hydrogen storage system,2LiBH_(4)-MgH_(2)holds an ultrahigh hydrogen storage capacity of 11.5 wt%.However,it suffers from sluggish hydrogen storage kinetics due to the difficult nucleation of MgB_(2).Herein,amorphous VB_(2)nanoparticles with an average size of approximately 32 nm are synthesized to enhance the hydrogen storage performance of 2LiBH_(4)-MgH_(2)composite.VB_(2),sharing the same hexagonal structure with MgB_(2)with a d-value mismatch ratio of only 2.28%,could serve as effective nucleation sites for promoting the formation of MgB_(2).Theoretical calculations reveal that the introduction of VB_(2)significantly reduces the binding energies of B and Mg,facilitating in situ nucleation of MgB_(2).As a result,after the introduction of VB_(2)nanoparticles,complete hydrogen desorption of 9.23 wt%is achieved for 2LiBH_(4)-MgH_(2)within 2 h at 400℃,which is 4 times shorter than the time required for pure 2LiBH_(4)-MgH_(2),and no nucleation incubation period for hydrogen desorption is observed even at a low temperature of380℃.More importantly,a reversible capacity of9.3 wt%,corresponding to a capacity retention of 100%,could be preserved after 10 cycles of hydrogen storage,demonstrating stable reversible hydrogen storage performance.This study provides a novel technological pathway for improving the reversible hydrogen storage performance of composite metal hydrides and offers significant insights into the development of high-performance hydrogen storage materials.
基金supported by the Chongqing Special Key Project of Technology Innovation and Application Development,China(cstc2019jscx-dxwt B0029)the National Natural Science Foundation of China(51871143)+5 种基金the Science and Technology Committee of Shanghai(19010500400)the Shanghai Rising-Star Program(21QA1403200)Chongqing Research Program of Basic Research and Frontier Technology(No.cstc2019jcyj-msxm X0306)the Start-up Funds of Chongqing University(02110011044171)the Senior Talent Start-up Funds of Jiangsu University(4111310024)the Independent Research Project of State Key Laboratory of Mechanical Transmissions(SKLMT-ZZKT-2021M11)
文摘Mg-based materials are one of the most promising hydrogen storage candidates due to their high hydrogen storage capacity,environmental benignity,and high Clarke number characteristics.However,the limited thermodynamics and kinetic properties pose major challenges for their engineering applications.Herein,we review the recent progress in improving their thermodynamics and kinetics,with an emphasis on the models and the influence of various parameters in the calculated models.Subsequently,the impact of alloying,composite,and nanocrystallization on both thermodynamics and dynamics are discussed in detail.In particular,the correlation between various modification strategies and the hydrogen capacity,dehydrogenation enthalpy and temperature,hydriding/dehydriding rates are summarized.In addition,the mechanism of hydrogen storage processes of Mg-based materials is discussed from the aspect of classical kinetic theories and microscope hydrogen transferring behavior.This review concludes with an outlook on the remaining challenge issues and prospects.
基金support from the National Key Research&Development Program(2022YFB3803700)of ChinaNational Natural Science Foundation(No.52171186)financial support from the Center of Hydrogen Science,Shanghai Jiao Tong University。
文摘With the depletion of fossil fuels and global warming,there is an urgent demand to seek green,low-cost,and high-efficiency energy resources.Hydrogen has been considered as a potential candidate to replace fossil fuels,due to its high gravimetric energy density(142 MJ kg^(-1)),high abundance(H_(2)O),and environmentalfriendliness.However,due to its low volume density,effective and safe hydrogen storage techniques are now becoming the bottleneck for the"hydrogen economy".Under such a circumstance,Mg-based hydrogen storage materials garnered tremendous interests due to their high hydrogen storage capacity(~7.6 wt%for MgH_(2)),low cost,and excellent reversibility.However,the high thermodynamic stability(ΔH=-74.7 kJ mol^(-1)H_(2))and sluggish kinetics result in a relatively high desorption temperature(>300℃),which severely restricts widespread applications of MgH_(2).Nano-structuring has been proven to be an effective strategy that can simultaneously enhance the ab/de-sorption thermodynamic and kinetic properties of MgH_(2),possibly meeting the demand for rapid hydrogen desorption,economic viability,and effective thermal management in practical applications.Herein,the fundamental theories,recent advances,and practical applications of the nanostructured Mg-based hydrogen storage materials are discussed.The synthetic strategies are classified into four categories:free-standing nano-sized Mg/MgH_(2)through electrochemical/vapor-transport/ultrasonic methods,nanostructured Mg-based composites via mechanical milling methods,construction of core-shell nano-structured Mg-based composites by chemical reduction approaches,and multi-dimensional nano-sized Mg-based heterostructure by nanoconfinement strategy.Through applying these strategies,near room temperature ab/de-sorption(<100℃)with considerable high capacity(>6 wt%)has been achieved in nano Mg/MgH_(2)systems.Some perspectives on the future research and development of nanostructured hydrogen storage materials are also provided.
文摘Over the last decade’s magnesium and magnesium based compounds have been intensively investigated as potential hydrogen storage as well as thermal energy storage materials due to their abundance and availability as well as their extraordinary high gravimetric and volumetric storage densities.This review work provides a broad overview of the most appealing systems and of their hydrogenation/dehydrogenation properties.Special emphasis is placed on reviewing the efforts made by the scientific community in improving the material’s thermodynamic and kinetic properties while maintaining a high hydrogen storage capacity.
基金H.Shao acknowledges the Macao Science and Technol-ogy Development Fund(FDCT)for funding(project no.118/2016/A3 and 0062/2018/A2)and this work was also par-tially supported by a Start-Up Research Fund from the Uni-versity of Macao(SRG2016-00088-FST)+5 种基金Q.Li also thanks the financial support from the National Natural Science Foun-dation of China(51671118)Young Elite Scientists Sponsor-ship Program by CAST(2017QNRC001)the“Chenguang”Program from the Shanghai Municipal Education Commission(17CG42)Science and Technology Committee of Shanghai(16520721800)the Program for Professor of Special Ap-pointment(Eastern Scholar)by Shanghai Municipal Educa-tion Commission(No.TP2015040).。
文摘Mg-based materials have been intensively studied for hydrogen storage applications due to their high energy density up to 2600 Wh/kg or 3700 Wh/L.However,the Mg-based materials with poor kinetics and the necessity for a high temperature to achieve 0.1 MPa hydrogen equilibrium pressure limit the applications in the onboard storage in Fuel cell vehicles(FCVs).Over the past decades,many methods have been applied to improve the hydriding/dehydriding(H/D)kinetics of Mg/MgH 2 by forming amorphous or nanosized particles,adding catalysts and employing external energy field,etc.However,which method is more effective and the intrinsic mechanism they work are widely differing versions.The hydrogenation and dehydrogenation behaviors of Mg-based alloys analyzing by kinetic models is an efficient way to reveal the H/D kinetic mechanism.However,some recently proposed models with physical meaning and simple analysis method are not known intimately by researchers.Therefore,this review focuses on the enhancement method of kinetics in Mg-based hydrogen storage materials and introduces the new kinetic models.
基金financially supported by the National Natural Science Foundation of China(Nos.51771171 and 51971199)the Natural Science Foundation of Guangxi Province(Nos.2019GXNSFBA185004 and 2018GXNSFAA281308)the Basic Ability Improvement Project for Young and Middle-Aged Teachers in Colleges and Universities in Guangxi(No.2019KY0021)。
文摘Magnesium hydride(MgH_(2)) is a candidate material for hydrogen storage.MgH_(2)-AlH_(3) composite shows superior hydrogen desorption properties than pure MgH_(2).However,this composite still suffers from poor cycling performance.In this work,NbF_(5) was utilized to improve the cycling properties of the MgH_(2)-AlH_(3) composite.Cycling hydrogen desorption studies show that NbF_(5) significantly improves the cycling stability of MgH_(2)-AlH_(3).The MgH_(2)-AlH_(3)-NbF_(5) composite can release about 2.7 wt% of hydrogen at 300℃ for 1 h and the hydrogen desorption capacity can maintain at 2.7 wt% for more than100 cycles.In comparison,the hydrogen desorption capacity of the MgH_(2)-AlH_(3) composite is decreasing with the cycle number increasing.The capacity is reduced from a maximum value of 3.3 wt% to about 1.0 wt% after 40 cycles.Brunauer-Emmett-Teller(BET) surface area measurements show that the particle size of MgH_(2)-AlH_(3) composite decreases after cycling,which means pulverization of the composite.NbF_(5) can to some extent suppress the pulverization of the composite during cycling,which partially contributes to the improvement of the cycling hydrogen desorption properties of the material.
基金the National Natural Science Foundation of China(Nos.51302079,51702138 and 51403193)the Natural Science Foundation of Hunan Province(No.2017JJ1008)the Key Research and Development Program of Hunan Province of China(No.2018GK2031)。
文摘Supercapacitors are favorable energy storage devices in the field of emerging energy technologies with high power density,excellent cycle stability and environmental benignity.The performance of supercapacitors is definitively influenced by the electrode materials.Nickel sulfides have attracted extensive interest in recent years due to their specific merits for supercapacitor application.However,the distribution of electrochemically active sites critically limits their electrochemical performance.Notable improvements have been achieved through various strategies such as building synergetic structures with conductive substrates,enhancing the active sites by nanocrystallization and constructing nanohybrid architecture with other electrode materials.This article overviews the progress in the reasonable design and preparation of nickel sulfides and their composite electrodes combined with various bifunctional electric double-layer capacitor(EDLC)-based substances(e.g.,graphene,hollow carbon)and pseudocapacitive materials(e.g.,transition-metal oxides,sulfides,nitrides).Moreover,the corresponding electrochemical performances,reaction mechanisms,emerging challenges and future perspectives are briefly discussed and summarized.
基金supported by Tianjin Municipal Science and Technology Commission(16PTSYJC00010)in China
文摘Rechargeable batteries and supercapacitors are widely investigated as the most important electrochemical energy storage devices nowadays due to the booming energy demand for electric vehicles and hand-held electronics. The large surface-area-to-volume ratio and internal surface areas endow two-dimensional（2D） materials with high mobility and high energy density; therefore, 2D materials are very promising candidates for Li ion batteries and supercapacitors with comprehensive investigations. In 2011, a new kind of 2D transition metal carbides, nitrides and carbonitrides, MXene, were successfully obtained from MAX phases. Since then about 20 different kinds of MXene have been prepared. Other precursors besides MAX phases and even other methods such as chemical vapor deposition（CVD） were also applied to prepare MXene, opening new doors for the preparation of new MXene. Their 2D nature and good electronic properties ensure the inherent advantages as electrode materials for electrochemical energy storage. In this review, we summarize the recent progress in the development of MXene with emphasis on the applications to electrochemical energy storage. Also, future perspective and challenges of MXene-based materials are briefly discussed regrading electrochemical energy storage.
文摘A SnO-graphite composite material, which can deliver high capacities and good cycling stability compared with unsupported SnO, was described. This material prepared via chemical co-precipitation reaction in the presence of graphite consists of high dispersion of SnO with a size of about several hundred nanometers in the graphite. The phase structure was analyzed by X-ray diffraction (XRD). The morphology and the element distribution were examined by scanning electron microscopy (SEM) equipped with energy spectrum. The results show that the SnO-graphite composites produced by slowly hydrolysis have higher rechargeable capacities than pure graphite and better cycling performance than SnO.
基金the National Support Projects of the Eleventh Five-year Plan (No. 2006BAJ02B01)the Special Research Projects of Shaanxi Province Education Department (No. 08JK316)the Key Discipline Construction Projects of Shaanxi Province for Funding Support
文摘The thermal energy storage phase change material used for building has been prepared with a few of fatty acids based on the principle of binary low eutectic point. The thermal behaviors such as phase transition temperature and enthalpy of compound energy storage material are researched through differential scanning calorimeter(DSC) and scanning electron microscope(SEM) . The results show that the thermal energy storage phase change composite material can be used in the wall panels well as its higher latent heat.
