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
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
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
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
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
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 development of high temperature phase change materials(PCMs)with great comprehensive performance is significant in the future thermal energy storage system.In this study,novel and durable Al-Si/Al_(2)O_(3)-Al N co...The development of high temperature phase change materials(PCMs)with great comprehensive performance is significant in the future thermal energy storage system.In this study,novel and durable Al-Si/Al_(2)O_(3)-Al N composite PCMs with controllable melting temperature were successfully synthesized by using pristine Al powder as raw material and tetraethyl orthosilicate as SiO_(2)source.The Al_(2)O_(3)shell and Al-Si alloy were in-situ produced via the substitution reaction between molten Al and SiO_(2).Importantly,the crack caused by the incomplete encapsulation of the Al_(2)O_(3)shell could repair itself by the nitridation reaction of internal molten Al and thereby forming a highly dense Al_(2)O_(3)-Al N composite shell.The produced dense Al_(2)O_(3)-Al N composite shell could significantly improve the thermal cycling stability of composite PCMs,and thus,the thermal storage density decrease of the Al-Si/Al_(2)O_(3)-Al N(59.8 J/g to77.7 J/g)was far less than that of the Al-Si/Al_(2)O_(3)(118.5 J/g)after 3000 thermal cycles.Moreover,the synthesized Al-Si/Al_(2)O_(3)-Al N still exhibited a controllable melting temperature(571.5-637.9℃),relatively high thermal storage density(105.6-150.7 J/g),great dimensional stability and structural stability after3000 thermal cycles.Hence,the synthesized Al-Si/Al_(2)O_(3)-Al N composite PCMs,as promising preferential thermal energy storage materials,can be stably used in the energy utilization efficiency improvement of various systems for more than 6 years.展开更多
A novel process for synthesis gas production over Circulating Fluidized Bed （CFB） using oxygen storage materials as oxygen carder was reported. First, oxygen in the air was chemically fixed and converted to lattice ...A novel process for synthesis gas production over Circulating Fluidized Bed （CFB） using oxygen storage materials as oxygen carder was reported. First, oxygen in the air was chemically fixed and converted to lattice oxygen of oxygen storage materials over regenerator, and then methane was selectively oxidized to synthesis gas with lattice oxygen of oxygen storage materials over riser reactor. The results from simulation reaction of CFB by sequential redox reaction on a fixed bed reactor using lanthanum-based perovskite LaFeO3 and La0.8Sr0.2Fe0.9CO0.1O3 oxides prepared by sol-gel, suggested that the depleted oxygen species could be regenerated, and methane could be oxidized to synthesis gas by lattice oxygen with high selectivity. The partial oxidation of methane to synthesis gas over CFB using lattice oxygen of the oxygen storage materials instead of gaseous oxygen should be possibly applicable.展开更多
There was an obvious relationship between seed testa structure, storage material and resistance to A. flavus of peanut. Results showed that seed testa of peanut germplasm with high resistance （HR） to A. flavus infec...There was an obvious relationship between seed testa structure, storage material and resistance to A. flavus of peanut. Results showed that seed testa of peanut germplasm with high resistance （HR） to A. flavus infection had thicker wax layer, integrated and tight epidermis layer, regular vascular tissue range. However, the seed testa of peanut germplasm with high sensitivity （HS） to A. flavus had the reverse results, and results of those with medium resistance （MR） to A. flavus lay in between, but changes of testa thickness were not significant among different resistance kinds. Results also showed that some seed storage materials were closely related with resistance potential to A. flavus. It seemed that varieties with higher resistance to A. flavus had higher oleic acid and protein content, lower linoleic acid and fat content. Content of palm acid, total sugar and VE did not show positive relationship with the resistance to A. flavus.展开更多
An evident improvement on activation properties of hydrogen storage was made by sput- tering an amorphous coating of commercial Si on TiFe alloy.SEM observation revealed an obvious difference between the morphologies ...An evident improvement on activation properties of hydrogen storage was made by sput- tering an amorphous coating of commercial Si on TiFe alloy.SEM observation revealed an obvious difference between the morphologies before and after hydrogen storage for TiFe alloy with or without amorphous Si coating.It is believed that this may be quite a developable hydrogen storage material.展开更多
In this paper, the mechanical and thermal properties of a sand-clay ceramic with additives coal bottom ash (CBA) waste from incinerator coal power plant are investigated to develop an alternative material for thermal ...In this paper, the mechanical and thermal properties of a sand-clay ceramic with additives coal bottom ash (CBA) waste from incinerator coal power plant are investigated to develop an alternative material for thermal energy storage (TES). Ceramic balls are developed at 1000°C and 1060°C using sintering or firing method. The obtained ceramics were compressed with a compression machine and thermally analyse using Decagon devise KD2 Pro thermal analyser. A muffle furnace was also used for thermal cycling at 610°C. It was found that the CBA increased the porosity, which resulted in the increase of the axial tensile strength reaching 3.5 MPa for sand-clay and ash ceramic. The ceramic balls with the required tensile strength for TES were selected. Their volumetric heat capacity, and thermal conductivity range respectively from 2.4075 MJ·m-3·°C-1 to 3.426 MJ·m-3·°C-1 and their thermal conductivity from 0.331 Wm-1·K-1, to 1.014 Wm-1·K-1 depending on sand origin, size and firing temperature. The selected formulas have good thermal stability because the most fragile specimens after 60 thermal cycles did not present any cracks. These properties allow envisioning the use of the ceramic balls developed as filler material for thermocline thermal energy storage (structured beds) in Concentrating Solar Power plants. And for other applications like solar cooker and solar dryer.展开更多
Thermal energy storage is an attractive option for effectiveness since it gives flexibility and reduces energy consumption and costs. New composite materials for storage and transformation of heat of NaCl-Al2O3composi...Thermal energy storage is an attractive option for effectiveness since it gives flexibility and reduces energy consumption and costs. New composite materials for storage and transformation of heat of NaCl-Al2O3composite materials were synthesized by one-step synthesis method. The chemical composition, morphology, structure, and thermal properties were investigated by XRD, EDS, SEM, and DSC. The results show that NaCl can be absorbed by Al2O3particle from 800 to 900 ℃ for Al2O3particle surface is rich active structure. The results also indicate that the leakage of NaCl when the phase change can be prevented by Al2O3particles and the enthalpy of phase change of NaCl-Al2O3material is 362 J/g. The composites have an excellent heat storage capacity. Therefore, this study contributes to one new thought and method to prepare high temperature heat storage material and this material can be applied in future thermal engineering.展开更多
To meet the demands of the global energy transition,photothermal phase change energy storage materials have emerged as an innovative solution.These materials,utilizing various photothermal conversion carriers,can pass...To meet the demands of the global energy transition,photothermal phase change energy storage materials have emerged as an innovative solution.These materials,utilizing various photothermal conversion carriers,can passively store energy and respond to changes in light exposure,thereby enhancing the efficiency of energy systems.Photothermal phase change energy storage materials show immense potential in the fields of solar energy and thermal management,particularly in addressing the intermittency issues of solar power.Their multifunctionality and efficiency offer broad application prospects in new energy technologies,construction,aviation,personal thermal management,and electronics.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
Crystal structure determines electrochemical energy storage characteristics;this is the underlying logic of material design.To date,hundreds of electrode materials have been developed to pursue superior performance.Ho...Crystal structure determines electrochemical energy storage characteristics;this is the underlying logic of material design.To date,hundreds of electrode materials have been developed to pursue superior performance.However,it remains a great challenge to understand the fundamental structure–performance relationship and achieve quantitative crystal structure design for efficient energy storage.In this review,we introduce the concept of crystal packing factor(PF),which can quantify crystal packing density.We then present and classify the typical crystal structures of attractive cathode/anode materials.Comparative PF analyses of different materials,including polymorphs,isomorphs,and others,are performed to clarify the influence of crystal packing density on energy storage performance through electronic and ionic conductivities.Notably,the practical electronic/ionic conductivities of energy storage materials are based on their intrinsic characteristics related to the PF yet are also affected by extrinsic factors.The PF provides a novel avenue for understanding the electrochemical performance of pristine materials and may offer guidance on designing better materials.Additional approaches involve size regulation,doping,carbon additives,and other methods.We also propose extended PF concepts to understand charge storage and transport behavior at different scales.Finally,we provide our insights on the major challenges and prospective solutions in this highly exciting field.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
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.
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.
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.
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financially supported by the National Natural Science Foundation of China(No.51771158)the Development and Reform Commission of Shenzhen Municipality(No.ZX20190229)。
文摘The development of high temperature phase change materials(PCMs)with great comprehensive performance is significant in the future thermal energy storage system.In this study,novel and durable Al-Si/Al_(2)O_(3)-Al N composite PCMs with controllable melting temperature were successfully synthesized by using pristine Al powder as raw material and tetraethyl orthosilicate as SiO_(2)source.The Al_(2)O_(3)shell and Al-Si alloy were in-situ produced via the substitution reaction between molten Al and SiO_(2).Importantly,the crack caused by the incomplete encapsulation of the Al_(2)O_(3)shell could repair itself by the nitridation reaction of internal molten Al and thereby forming a highly dense Al_(2)O_(3)-Al N composite shell.The produced dense Al_(2)O_(3)-Al N composite shell could significantly improve the thermal cycling stability of composite PCMs,and thus,the thermal storage density decrease of the Al-Si/Al_(2)O_(3)-Al N(59.8 J/g to77.7 J/g)was far less than that of the Al-Si/Al_(2)O_(3)(118.5 J/g)after 3000 thermal cycles.Moreover,the synthesized Al-Si/Al_(2)O_(3)-Al N still exhibited a controllable melting temperature(571.5-637.9℃),relatively high thermal storage density(105.6-150.7 J/g),great dimensional stability and structural stability after3000 thermal cycles.Hence,the synthesized Al-Si/Al_(2)O_(3)-Al N composite PCMs,as promising preferential thermal energy storage materials,can be stably used in the energy utilization efficiency improvement of various systems for more than 6 years.
基金Project supported by the National Natural Science Foundation of China (20306016, 20322201)
文摘A novel process for synthesis gas production over Circulating Fluidized Bed （CFB） using oxygen storage materials as oxygen carder was reported. First, oxygen in the air was chemically fixed and converted to lattice oxygen of oxygen storage materials over regenerator, and then methane was selectively oxidized to synthesis gas with lattice oxygen of oxygen storage materials over riser reactor. The results from simulation reaction of CFB by sequential redox reaction on a fixed bed reactor using lanthanum-based perovskite LaFeO3 and La0.8Sr0.2Fe0.9CO0.1O3 oxides prepared by sol-gel, suggested that the depleted oxygen species could be regenerated, and methane could be oxidized to synthesis gas by lattice oxygen with high selectivity. The partial oxidation of methane to synthesis gas over CFB using lattice oxygen of the oxygen storage materials instead of gaseous oxygen should be possibly applicable.
文摘There was an obvious relationship between seed testa structure, storage material and resistance to A. flavus of peanut. Results showed that seed testa of peanut germplasm with high resistance （HR） to A. flavus infection had thicker wax layer, integrated and tight epidermis layer, regular vascular tissue range. However, the seed testa of peanut germplasm with high sensitivity （HS） to A. flavus had the reverse results, and results of those with medium resistance （MR） to A. flavus lay in between, but changes of testa thickness were not significant among different resistance kinds. Results also showed that some seed storage materials were closely related with resistance potential to A. flavus. It seemed that varieties with higher resistance to A. flavus had higher oleic acid and protein content, lower linoleic acid and fat content. Content of palm acid, total sugar and VE did not show positive relationship with the resistance to A. flavus.
文摘An evident improvement on activation properties of hydrogen storage was made by sput- tering an amorphous coating of commercial Si on TiFe alloy.SEM observation revealed an obvious difference between the morphologies before and after hydrogen storage for TiFe alloy with or without amorphous Si coating.It is believed that this may be quite a developable hydrogen storage material.
文摘In this paper, the mechanical and thermal properties of a sand-clay ceramic with additives coal bottom ash (CBA) waste from incinerator coal power plant are investigated to develop an alternative material for thermal energy storage (TES). Ceramic balls are developed at 1000°C and 1060°C using sintering or firing method. The obtained ceramics were compressed with a compression machine and thermally analyse using Decagon devise KD2 Pro thermal analyser. A muffle furnace was also used for thermal cycling at 610°C. It was found that the CBA increased the porosity, which resulted in the increase of the axial tensile strength reaching 3.5 MPa for sand-clay and ash ceramic. The ceramic balls with the required tensile strength for TES were selected. Their volumetric heat capacity, and thermal conductivity range respectively from 2.4075 MJ·m-3·°C-1 to 3.426 MJ·m-3·°C-1 and their thermal conductivity from 0.331 Wm-1·K-1, to 1.014 Wm-1·K-1 depending on sand origin, size and firing temperature. The selected formulas have good thermal stability because the most fragile specimens after 60 thermal cycles did not present any cracks. These properties allow envisioning the use of the ceramic balls developed as filler material for thermocline thermal energy storage (structured beds) in Concentrating Solar Power plants. And for other applications like solar cooker and solar dryer.
基金Funded by the National Natural Science of China(No.2012BAA05B06)
文摘Thermal energy storage is an attractive option for effectiveness since it gives flexibility and reduces energy consumption and costs. New composite materials for storage and transformation of heat of NaCl-Al2O3composite materials were synthesized by one-step synthesis method. The chemical composition, morphology, structure, and thermal properties were investigated by XRD, EDS, SEM, and DSC. The results show that NaCl can be absorbed by Al2O3particle from 800 to 900 ℃ for Al2O3particle surface is rich active structure. The results also indicate that the leakage of NaCl when the phase change can be prevented by Al2O3particles and the enthalpy of phase change of NaCl-Al2O3material is 362 J/g. The composites have an excellent heat storage capacity. Therefore, this study contributes to one new thought and method to prepare high temperature heat storage material and this material can be applied in future thermal engineering.
基金supported by National Natural Science Foundation of China(grant nos.52327802,52303101,52173078,and 52130303)National Key R&D Program of China(no.2022YFB3805702).
文摘To meet the demands of the global energy transition,photothermal phase change energy storage materials have emerged as an innovative solution.These materials,utilizing various photothermal conversion carriers,can passively store energy and respond to changes in light exposure,thereby enhancing the efficiency of energy systems.Photothermal phase change energy storage materials show immense potential in the fields of solar energy and thermal management,particularly in addressing the intermittency issues of solar power.Their multifunctionality and efficiency offer broad application prospects in new energy technologies,construction,aviation,personal thermal management,and electronics.
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(52202327)Science and Technology Commission of Shanghai Municipality(22ZR1471300)the Key Research Program of Frontier Science,Chinese Academy of Sciences(Grant No.QYZDJ-SSW-JSC013 and KGZD-EW-T06).
文摘Crystal structure determines electrochemical energy storage characteristics;this is the underlying logic of material design.To date,hundreds of electrode materials have been developed to pursue superior performance.However,it remains a great challenge to understand the fundamental structure–performance relationship and achieve quantitative crystal structure design for efficient energy storage.In this review,we introduce the concept of crystal packing factor(PF),which can quantify crystal packing density.We then present and classify the typical crystal structures of attractive cathode/anode materials.Comparative PF analyses of different materials,including polymorphs,isomorphs,and others,are performed to clarify the influence of crystal packing density on energy storage performance through electronic and ionic conductivities.Notably,the practical electronic/ionic conductivities of energy storage materials are based on their intrinsic characteristics related to the PF yet are also affected by extrinsic factors.The PF provides a novel avenue for understanding the electrochemical performance of pristine materials and may offer guidance on designing better materials.Additional approaches involve size regulation,doping,carbon additives,and other methods.We also propose extended PF concepts to understand charge storage and transport behavior at different scales.Finally,we provide our insights on the major challenges and prospective solutions in this highly exciting field.
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).
