Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the e...Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials.展开更多
Improving the volumetric energy density of supercapacitors is essential for practical applications,which highly relies on the dense storage of ions in carbon-based electrodes.The functional units of carbon-based elect...Improving the volumetric energy density of supercapacitors is essential for practical applications,which highly relies on the dense storage of ions in carbon-based electrodes.The functional units of carbon-based electrode exhibit multi-scale structural characteristics including macroscopic electrode morphologies,mesoscopic microcrystals and pores,and microscopic defects and dopants in the carbon basal plane.Therefore,the ordered combination of multi-scale structures of carbon electrode is crucial for achieving dense energy storage and high volumetric performance by leveraging the functions of various scale structu re.Considering that previous reviews have focused more on the discussion of specific scale structu re of carbon electrodes,this review takes a multi-scale perspective in which recent progresses regarding the structureperformance relationship,underlying mechanism and directional design of carbon-based multi-scale structures including carbon morphology,pore structure,carbon basal plane micro-environment and electrode technology on dense energy storage and volumetric property of supercapacitors are systematically discussed.We analyzed in detail the effects of the morphology,pore,and micro-environment of carbon electrode materials on ion dense storage,summarized the specific effects of different scale structures on volumetric property and recent research progress,and proposed the mutual influence and trade-off relationship between various scale structures.In addition,the challenges and outlooks for improving the dense storage and volumetric performance of carbon-based supercapacitors are analyzed,which can provide feasible technical reference and guidance for the design and manufacture of dense carbon-based electrode materials.展开更多
It is regretful that the Acknowledgments part was lost in the final process of publication.The Acknowledgments part should be added as follow.The work described in this paper was supported by the grants from the Resea...It is regretful that the Acknowledgments part was lost in the final process of publication.The Acknowledgments part should be added as follow.The work described in this paper was supported by the grants from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.16205721).展开更多
This paper presents a new type of triangular Sharp Eagle wave energy converter(WEC)platform.On the basis of the linear potential flow theory and the finite element analysis method,the hydrodynamic performance and stru...This paper presents a new type of triangular Sharp Eagle wave energy converter(WEC)platform.On the basis of the linear potential flow theory and the finite element analysis method,the hydrodynamic performance and structural response of the platform are studied,considering the actual platform motion and free surface rise under extreme sea states.First,the effects of the wave frequency and direction on the wave-induced loads and dynamic responses were examined.The motion at a wave direction angle of 0°is relatively low.On this basis,the angle constrained by the two sides of the Sharp Eagle floaters should be aligned with the main wave direction to avoid significant platform motion under extreme sea states.Additionally,the structural response of the platform,including the wave-absorbing floaters,is investigated.The results highlighted that the conditions or locations where yielding,buckling,and fatigue failures occur were different.In this context,the connection area of the Sharp Eagle floaters and platform is prone to yielding failure under oblique wave action,whereas the pontoon and side of the Sharp Eagle floaters are prone to buckling failure during significant vertical motion.Additionally,fatigue damage is most likely to occur at the connection between the middle column on both sides of the Sharp Eagle floaters and the pontoons.The findings of this paper revealed an intrinsic connection between wave-induced loads and the dynamic and structural responses of the platform,which provides a useful reference for the improved design of WECs.展开更多
To reveal the rock burst mechanism,the stress and failure characteristics of coal-rock strata under different advancing speeds of mining working face were explored by theoretical analysis,simulation,and engineering mo...To reveal the rock burst mechanism,the stress and failure characteristics of coal-rock strata under different advancing speeds of mining working face were explored by theoretical analysis,simulation,and engineering monitoring.The relationship between energy accumulation and release was analyzed,and a reasonable mining speed according to specific projects was recommended.The theoretical analysis shows that as the mining speed increases from 4 to 15 m/d,the rheological coefficient of coal mass ranges from 0.9 to 0.4,and the elastic energy of coal mass accumulation varies from 100 to 900 kJ.Based on the simulation,there is a critical advancing speed,the iteration numbers of simulation are less than 15,000 per mining 10 m coal seam,the overburden structure is obvious,the abutment pressure in coal mass is large,and the accumulated energy is large,which is easy to cause strong rock burst.When the iteration number is greater than 15,000,the static force of coal mass increases slightly,but there is no obvious rock burst.Based on engineering monitoring,the mining speed of a mine is less than 8 m/d,and the periodic weighting distance is about 17 m;as the mining speed is greater than 10 m/d,and the periodic weighting distance is greater than 20 m;as the mining speed is 3-8 m/d,and the range of high stress in surrounding rock is 48 m;as the advancing speed is 8-12 m/d,and the high-stress range in surrounding rock is 80 m.Moreover,as the mining speed is less than 8 cut cycles,the micro seismic energy is less than 10,000 J;as the mining speed is 12 cut cycles,the microseismic energy is about 20,000 J.In summary,the advancing speed is positively correlated with the micro seismic event;as the mining speed increases,the accumulated elastic energy of surrounding rock is greater,which is easy to cause rock burst.The comprehensive analysis indicates the daily advance speed of the mine is not more than 12 cut cycles.展开更多
The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of ...The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of adsorbent and catalyst.Herein,we engineered a series of RuNa/γ-Al_(2)O_(3)materials,varying the size of ruthenium from single atoms to clusters/nanoparticles.The coordination environment and structure sensitivity of ruthenium were quantitatively investigated at atomic scale.Our findings reveal that the reduced Ru nanoparticles,approximately 7.1 nm in diameter with a Ru-Ru coordination number of 5.9,exhibit high methane formation activity and selectivity at 340°C.The Ru-Na interfacial sites facilitate CO_(2)migration through a deoxygenation pathway,involving carbonate dissociation,carbonyl formation,and hydrogenation.In-situ experiments and theoretical calculations show that stable carbonyl intermediates on metallic Ru nanoparticles facilitate heterolytic C–O scission and C–H bonding,significantly lowering the energy barrier for activating stored CO_(2).展开更多
The nanofluid-based direct absorption solar collector(NDASC)ensures that solar radiation passing through the tube wall is directly absorbed by the nanofluid,reducing thermal resistance in the energy transfer process.H...The nanofluid-based direct absorption solar collector(NDASC)ensures that solar radiation passing through the tube wall is directly absorbed by the nanofluid,reducing thermal resistance in the energy transfer process.However,further exploration is required to suppress the outward thermal losses from the nanofluid at high temperatures.Herein,this paper proposes a novel NDASC in which the outer surface of the collector tube is covered with functional coatings and a three-dimensional computational fluid dynamics model is established to study the energy flow distributions on the collector within the temperature range of 400-600 K.When the nanofluid’s absorption coefficient reaches 80 m^(-1),the NDASC shows the optimal thermal performance,and the NDASC with local Sn-In_(2)O_(3) coating achieves a 7.8% improvement in thermal efficiency at 400 K compared to the original NDASC.Furthermore,hybrid coatings with Sn In_(2)O_(3)/WTi-Al_(2)O_(3) are explored,and the optimal coverage angles are determined.The NDASC with such coatings shows a 10.22%-17.9% increase in thermal efficiency compared to the original NDASC and a 7.6%-19.5% increase compared to the traditional surface-type solar collectors,demonstrating the effectiveness of the proposed energy flow control strategy for DASCs.展开更多
Photovoltaic(PV)power forecasting is essential for balancing energy supply and demand in renewable energy systems.However,the performance of PV panels varies across different technologies due to differences in efficie...Photovoltaic(PV)power forecasting is essential for balancing energy supply and demand in renewable energy systems.However,the performance of PV panels varies across different technologies due to differences in efficiency and how they process solar radiation.This study evaluates the effectiveness of deep learning models in predicting PV power generation for three panel technologies:Hybrid-Si,Mono-Si,and Poly-Si,across three forecasting horizons:1-step,12-step,and 24-step.Among the tested models,the Convolutional Neural Network—Long Short-Term Memory(CNN-LSTM)architecture exhibited superior performance,particularly for the 24-step horizon,achieving R^(2)=0.9793 and MAE 0.0162 for the Poly-Si array,followed by Mono-Si(R^(2)=0.9768)and Hybrid-Si arrays(R^(2)=0.9769).These findings demonstrate that the CNN-LSTM model can provide accurate and reliable PV power predictions for all studied technologies.By identifying the most suitable predictive model for each panel technology,this study contributes to optimizing PV power forecasting and improving energy management strategies.展开更多
Amidst the global push for decarbonization,solar-powered Organic Rankine Cycle(SORC)systems are gaining significant attention.The small-scale Organic Rankine Cycle(ORC)systems have enhanced environmental adaptability,...Amidst the global push for decarbonization,solar-powered Organic Rankine Cycle(SORC)systems are gaining significant attention.The small-scale Organic Rankine Cycle(ORC)systems have enhanced environmental adaptability,improved system flexibility,and achieved diversification of application scenarios.However,the power consumption ratio of the working fluid pump becomes significantly larger relative to the total power output of the system,adversely impacting overall system efficiency.This study introduces an innovative approach by incorporating a vapor-liquid ejector into the ORC system to reduce the pump work consumption within the ORC.The thermoeconomic models for both the traditional ORC and an ORC integrated with a vapor-liquid ejector driven by solar parabolic trough collectors(PTCs)were developed.Key evaluation indicators,such as thermal efficiency,exergy efficiency,specific investment cost,and levelized cost of energy,were employed to compare the SORC with the solar ejector organic Rankine cycle(SEORC).Additionally,the study explores the effects of solar beam radiation intensity,PTC temperature variation,evaporator pinch point temperature difference,and condenser pinch point temperature difference on the thermo-economic performance of both systems.Results demonstrate that SEORC consistently outperforms SORC.Higher solar radiation intensity and increased PTC inlet temperature lead to better system efficiency.Moreover,there is an optimal PTC temperature drop where both thermal and exergy efficiencies are maximized.The influence of evaporator and condenser temperature pinches on system performance is found to be inconsistent.展开更多
The replacement of non-aqueous organic electrolytes with solid-state electrolytes(SSEs)in solid-state lithium metal batteries(SLMBs)is considered a promising strategy to address the constraints of lithium-ion batterie...The replacement of non-aqueous organic electrolytes with solid-state electrolytes(SSEs)in solid-state lithium metal batteries(SLMBs)is considered a promising strategy to address the constraints of lithium-ion batteries,especially in terms of energy density and reliability.Nevertheless,few SLMBs can deliver the required cycling performance and long-term stability for practical use,primarily due to suboptimal interface properties.Given the diverse solidification pathways leading to different interface characteristics,it is crucial to pinpoint the source of interface deterioration and develop appropriate remedies.This review focuses on Li|SSE interface issues between lithium metal anode and SSE,discussing recent advancements in the understanding of(electro)chemistry,the impact of defects,and interface evolutions that vary among different SSE species.The state-ofthe-art strategies concerning modified SEI,artificial interlayer,surface architecture,and composite structure are summarized and delved into the internal relationships between interface characteristics and performance enhancements.The current challenges and opportunities in characterizing and modifying the Li|SSE interface are suggested as potential directions for achieving practical SLMBs.展开更多
Developing fast-charging lithium-ion batteries(LIBs)that feature high energy density is critical for the scalable application of electric vehicles.Iron vanadate(FVO)holds great potential as anode material in fast-char...Developing fast-charging lithium-ion batteries(LIBs)that feature high energy density is critical for the scalable application of electric vehicles.Iron vanadate(FVO)holds great potential as anode material in fast-charging LIBs because of its high theoretical specific capacity and the high natural abundance of its constituents.However,the capacity of FVO rapidly decays due to its low electrical conductivity.Herein,uniform FVO nanoparticles are grown in situ on ordered mesoporous carbon(CMK-3)support,forming a highly electrically conductive porous network,FVO/CMK-3.The structure of CMK-3 helps prevent agglomeration of FVO particles.The electrically conductive nature of CMK-3 can further enhance the electrical conductivity of FVO/CMK-3 and buffer the volume expansion of FVO particles during cycling processes.As a result,the FVO/CMK-3 displays excellent fast-charging performance of 364.6 mAh·g^(-1)capacity for 2500 cycles at 10 A·g^(-1)(with an ultralow average capacity loss per cycle of 0.003%)through a pseudocapacitive-dominant process.Moreover,the LiCoO_(2)//FVO/CMK-3 full cell achieves a high capacity of 100.2 mAh·g^(-1)and a high capacity retention(96.2%)after 200 cycles.The superior electrochemical performance demonstrates that FVO/CMK-3 is an ideal anode material candidate for fast-charging,stable LIBs with high energy density.展开更多
Rechargeable magnesium batteries are promising alternatives to traditional lithium batteries because of the high abundance of Mg compounds in earth crust,their low toxicity,and possible favorable properties as electro...Rechargeable magnesium batteries are promising alternatives to traditional lithium batteries because of the high abundance of Mg compounds in earth crust,their low toxicity,and possible favorable properties as electrodes'material.However,Mg metal anodes face several challenges,notably the natively existence of an inactive oxide layer on their surfaces,which reduces their effectiveness.Additionally,interactions of Mg electrodes with electrolyte solutions'components can lead to the formation of insulating surface layers,that can fully block them for ions transport.This review addresses these issues by focusing on surface treatments strategies to enhance electrochemical performance of Mg anodes.It highlights chemical and physical modification techniques to prevent oxidation and inactive-layers formation,as well as their practical implications for MIBs.We also examined the impact of Mg anodes'surface engineering on their electrochemical reversibility and cycling efficiency.Finally,future research directions to improve the performance and commercial viability of magnesium anodes and advance development of high-capacity,safe,and cost-effective energy storage systems based on magnesium electrochemistry are discussed.展开更多
Aluminum(Al)exhibits excellent electrical conductivity,mechanical ductility,and good chemical compatibility with high-ionic-conductivity electrolytes.This makes it more suitable as an anode material for all-solid-stat...Aluminum(Al)exhibits excellent electrical conductivity,mechanical ductility,and good chemical compatibility with high-ionic-conductivity electrolytes.This makes it more suitable as an anode material for all-solid-state lithium batteries(ASSLBs)compared to the overly reactive metallic lithium anode and the mechanically weak silicon anode.This study finds that the pre-lithiated Al anode demonstrates outstanding interfacial stability with the Li_6PS_5Cl(LPSCl)electrolyte,maintaining stable cycling for over 1200 h under conditions of deep charge-discharge.This paper combines the pre-lithiated Al anode with a high-nickel cathode,LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2),paired with the highly ionic conductive LPSCl electrolyte,to design an ASSLB with high energy density and stability.Using anode pre-lithiation techniques,along with dual-reinforcement technology between the electrolyte and the cathode active material,the ASSLB achieves stable cycling for 1000 cycles at a 0.2C rate,with a capacity retention rate of up to 82.2%.At a critical negative-to-positive ratio of 1.1,the battery's specific energy reaches up to 375 Wh kg^(-1),and it maintains over 85.9%of its capacity after 100 charge-discharge cycles.This work provides a new approach and an excellent solution for developing low-cost,high-stability all-solid-state batteries.展开更多
Sodium-ion batteries(SIBs) and potassium-ion batteries(PIBs) have been attracting great attentions and widely been exploited due to the abundant sodium/potassium resources.Hence,the preparation of high-powered anode m...Sodium-ion batteries(SIBs) and potassium-ion batteries(PIBs) have been attracting great attentions and widely been exploited due to the abundant sodium/potassium resources.Hence,the preparation of high-powered anode materials for SIBs/PIBs plays a decisive role for the commercial applications of SIBs/PIBs in the future.Manganese selenides are a class of potential anode materials for SIBs/PIBs because of their small band gap and high electrical conductivity.In this work,MnSe and ReS_(2) core-shell nanowires connecting by polydopamine derived carbon nanotube(MnSe@NC@ReS_(2)) have been successfully synthesized from growing ReS_(2) nanosheets array on the surface of MnSe@NC nano wires,which present excellent Na^(+)/K^(+) storage performance.While applied as SIBs anode,the specific capacity of 300 mAh·g^(-1) was maintwined after 400 cycles at the current density of 1.0 A·g^(-1).Besides,it could also keep 120 mAh·g^(-1) specific capacity after 900 cycles at 1.0 A·g^(-1) for the anode of PIBs.These heterogeneous engineering and one-dimensional-two-dimensional(1D-2D) hybrid strategies could provide an ideal strategy for the synthesis of new hetero-structured anode materials with outstanding battery performance for SIBs and PIBs.展开更多
Zn-based aqueous batteries(ZABs) are gaining widespread popularity due to their low cost and high safety profile. However, the application of ZABs faces significant challenges, such as dendrite growth and parasitic re...Zn-based aqueous batteries(ZABs) are gaining widespread popularity due to their low cost and high safety profile. However, the application of ZABs faces significant challenges, such as dendrite growth and parasitic reactions of metallic Zn anodes. Therefore, achieving high-energy–density ZABs necessitates addressing the fundamental thermodynamics and kinetics of Zn anodes. Various strategies are available to mitigate these challenges, with electrolyte additive engineering emerging as one of the most efficient and promising approaches. Despite considerable research in this field, a comprehensive understanding of the intrinsic mechanisms behind the high performance of electrolyte additives remains limited. This review aims to provide a detailed introduction to functional electrolyte additives and thoroughly explore their underlying mechanisms. Additionally, it discusses potential directions and perspectives in additive engineering for ZABs, offering insights into future development and guidelines for achieving high-performance ZABs.展开更多
Phase change materials(PCMs)are widely considered as promising energy storage materials for solar/electro-thermal energy storage.Nevertheless,the inherent low thermal/electrical conductivities of most PCMs limit their...Phase change materials(PCMs)are widely considered as promising energy storage materials for solar/electro-thermal energy storage.Nevertheless,the inherent low thermal/electrical conductivities of most PCMs limit their energy conversion efficiencies,hindering their practical applications.Herein,we fabricate a highly thermally/electrically conductive solid-solid phase change composite(PCC)enabled by forming aligned graphite networks through pressing the mixture of the trimethylolethane and porous expanded graphite(EG).Experiments indicate that both the thermal and electrical conductivities of the PCC increase with increasing mass proportion of the EG because the aligned graphite networks establish highly conductive pathways.Meanwhile,the PCC4 sample with the EG proportion of 20wt%can achieve a high thermal conductivity of 12.82±0.38W·m^(-1)·K^(-1)and a high electrical conductivity of 4.11±0.02S·cm^(-1)in the lengthwise direction.Furthermore,a solar-thermal energy storage device incorporating the PCC4,a solar selective absorber,and a highly transparent glass is developed,which reaches a high solar-thermal efficiency of 77.30±2.71%under 3.0 suns.Moreover,the PCC4 can also reach a high electro-thermal efficiency of 91.62±3.52%at a low voltage of 3.6V,demonstrating its superior electro-thermal storage performance.Finally,stability experiments indicate that PCCs exhibit stabilized performance in prolonged TES operations.Overall,this work offers highly conductive and cost-effective PCCs,which are suitable for large-scale and efficient solar/electro-thermal energy storage.展开更多
Chemical leaching of coals would be required to produce cleaner coals for some special applications where physical benefi-ciation may not be effective enough.This would also help in recovering Li and rare earth metals...Chemical leaching of coals would be required to produce cleaner coals for some special applications where physical benefi-ciation may not be effective enough.This would also help in recovering Li and rare earth metals besides in the sequestration of CO_(2).About 20 Indian coals having complexly distributed moderate to high ash contents were sequentially treated with various alkali–acid such as NaOH-HCl,HF,HCl,HCl-HF,and NaOH-HCl-HF leaching.This aimed to establish and design the best stepwise sequential process for the highest degree of demineralisation through a chemical leaching process.Kinetics and process intensification studies were carried out.More than 80%demineralisation of Madhaipur and Neemcha coals was observed using the best sequential treatment designed presently.The repeated stepwise treatment of the alkali and the acid was also studied,which was found to significantly enhance the degree of demineralisation of coals.The integrated process of alkali–acid leaching followed by solvent extraction(Organo-refining)and vice versa of the treated coal was also studied for producing cleaner coals.展开更多
The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis(PEMWE)emerging as the preeminent pathway for...The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis(PEMWE)emerging as the preeminent pathway for hydrogen production.Despite remarkable advancements in this field,confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable obstacle.This impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles detachment.To address these challenges,we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis system.Compared to constant voltage electrolysis(hydrogen production rate:51.6 m L h^(-1),energy consumption:5.37 kWh Nm-^(3)H_(2)),this strategy(hydrogen production rate:66 m L h^(-1),energy consumption:3.83 kWh Nm-^(3)H_(2))increases the hydrogen production rate by approximately 27%and reduces the energy consumption by about 28%.Furthermore,we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic(PV)system designed for outdoor operation,successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 V.The combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism:pulsed dynamic electrolysis(PDE)dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode surface.As such,PDE-enhanced PEMWE represents a synergistic advancement,concurrently enhancing both the hydrogen generation reaction and associated transport processes.This promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.展开更多
The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace K...The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace KOH-catalyzed CO_(2) activation.Comprehensive investigations were conducted on three aspects:physicochemical structure evolution of biochar,mechanistic understanding of trace KOH-facilitated CO_(2) activation processes,and application characteristics for CO_(2) adsorption.Results demonstrate that biochar activated by trace KOH(<10%)and CO_(2) achieves comparable specific surface area(1244.09 m^(2)/g)to that obtained with 100%KOH activation(1425.10 m^(2)/g).The pore structure characteristics(specific surface area and pore volume)are governed by CO and CH4 generated through K-salt catalyzed reactions between CO_(2) and biochar.The optimal CO_(2) adsorption capacities of KBC adsorbent reached 4.70 mmol/g(0℃)and 7.25 mmol/g(25℃),representing the maximum values among comparable carbon adsorbents.The 5%KBC-CO_(2) sample exhibited CO_(2) adsorption capacities of 3.19 and 5.01 mmol/g under respective conditions,attaining current average performance levels.Notably,CO_(2)/N_(2) selectivity(85∶15,volume ratio)reached 64.71 at 0.02 bar with robust cycling stability.Molecular dynamics simulations revealed that oxygen-containing functional groups accelerate CO_(2) adsorption kinetics and enhance micropore storage capacity.This technical route offers simplicity,environmental compatibility,and scalability,providing critical references for large-scale preparation of high-quality carbon materials.展开更多
Lithium-sulfur batteries(LSBs)have attracted widespread attention due to their high theoretical energy density.However,the dissolution of long-chain polysulfides into the electrolyte(the“shuttle effect”)leads to rap...Lithium-sulfur batteries(LSBs)have attracted widespread attention due to their high theoretical energy density.However,the dissolution of long-chain polysulfides into the electrolyte(the“shuttle effect”)leads to rapid capacity decay.Therefore,finding suitable materials to mitigate the shuttle effect of polysulfides is crucial for enhancing the electrochemical performance of lithium-sulfur batteries.In this study,LSBs’separator is modified with Ni_(3)V_(2)O_(8)nanoparticles@carboxylated carbon nanotubes(Ni_(3)V_(2)O_(8)@CNTs)composite.There are abundant oxygen vacancies in Ni_(3)V_(2)O_(8)@CNTs composite which plays a synergistic effect on shuttle effect.The Ni_(3)V_(2)O_(8)can tightly anchor soluble polysulfides through oxygen vacancies,while the CNTs not only facilitate the transport of ions and electrons but also weaken the migration of polysulfides,limiting shuttle effect.As a result,the cycling stability of LSBs using Ni_(3)V_(2)O_(8)@CNTs-modified separator has been significantly improved(with a capacity decay rate of only 0.0334%after 1500 cycles at 4.0C).This study proposes a strategy to design modified separator for high-performance LSBs.展开更多
基金supported by the National Natural Science Foundation of China(U21A20281)the Special Fund for Young Teachers from Zhengzhou University(JC23557030,JC23257011)+1 种基金the Key Research Projects of Higher Education Institutions of Henan Province(24A530009)the Project of Zhongyuan Critical Metals Laboratory(GJJSGFYQ202336).
文摘Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials.
基金funded by the Joint Fund for Regional Innovation and Development of National Natural Science Foundation of China(U21A20143)the National Science Fund for Excellent Young Scholars(52322607)the Excellent Youth Foundation of Heilongjiang Scientific Committee(YQ2022E028)。
文摘Improving the volumetric energy density of supercapacitors is essential for practical applications,which highly relies on the dense storage of ions in carbon-based electrodes.The functional units of carbon-based electrode exhibit multi-scale structural characteristics including macroscopic electrode morphologies,mesoscopic microcrystals and pores,and microscopic defects and dopants in the carbon basal plane.Therefore,the ordered combination of multi-scale structures of carbon electrode is crucial for achieving dense energy storage and high volumetric performance by leveraging the functions of various scale structu re.Considering that previous reviews have focused more on the discussion of specific scale structu re of carbon electrodes,this review takes a multi-scale perspective in which recent progresses regarding the structureperformance relationship,underlying mechanism and directional design of carbon-based multi-scale structures including carbon morphology,pore structure,carbon basal plane micro-environment and electrode technology on dense energy storage and volumetric property of supercapacitors are systematically discussed.We analyzed in detail the effects of the morphology,pore,and micro-environment of carbon electrode materials on ion dense storage,summarized the specific effects of different scale structures on volumetric property and recent research progress,and proposed the mutual influence and trade-off relationship between various scale structures.In addition,the challenges and outlooks for improving the dense storage and volumetric performance of carbon-based supercapacitors are analyzed,which can provide feasible technical reference and guidance for the design and manufacture of dense carbon-based electrode materials.
文摘It is regretful that the Acknowledgments part was lost in the final process of publication.The Acknowledgments part should be added as follow.The work described in this paper was supported by the grants from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.16205721).
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC3003805)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2022356)Guangzhou Basic and Applied Basic Research Project(Grant No.2023A04J0955).
文摘This paper presents a new type of triangular Sharp Eagle wave energy converter(WEC)platform.On the basis of the linear potential flow theory and the finite element analysis method,the hydrodynamic performance and structural response of the platform are studied,considering the actual platform motion and free surface rise under extreme sea states.First,the effects of the wave frequency and direction on the wave-induced loads and dynamic responses were examined.The motion at a wave direction angle of 0°is relatively low.On this basis,the angle constrained by the two sides of the Sharp Eagle floaters should be aligned with the main wave direction to avoid significant platform motion under extreme sea states.Additionally,the structural response of the platform,including the wave-absorbing floaters,is investigated.The results highlighted that the conditions or locations where yielding,buckling,and fatigue failures occur were different.In this context,the connection area of the Sharp Eagle floaters and platform is prone to yielding failure under oblique wave action,whereas the pontoon and side of the Sharp Eagle floaters are prone to buckling failure during significant vertical motion.Additionally,fatigue damage is most likely to occur at the connection between the middle column on both sides of the Sharp Eagle floaters and the pontoons.The findings of this paper revealed an intrinsic connection between wave-induced loads and the dynamic and structural responses of the platform,which provides a useful reference for the improved design of WECs.
基金supported by the National Natural Science Foundation of China(52174109)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(22IRTSTHN005)+1 种基金Key Research and Development Project of Henan Province(242102240029)Key Research Project of Institutions of Higher Education in Henan Province(24A580001).
文摘To reveal the rock burst mechanism,the stress and failure characteristics of coal-rock strata under different advancing speeds of mining working face were explored by theoretical analysis,simulation,and engineering monitoring.The relationship between energy accumulation and release was analyzed,and a reasonable mining speed according to specific projects was recommended.The theoretical analysis shows that as the mining speed increases from 4 to 15 m/d,the rheological coefficient of coal mass ranges from 0.9 to 0.4,and the elastic energy of coal mass accumulation varies from 100 to 900 kJ.Based on the simulation,there is a critical advancing speed,the iteration numbers of simulation are less than 15,000 per mining 10 m coal seam,the overburden structure is obvious,the abutment pressure in coal mass is large,and the accumulated energy is large,which is easy to cause strong rock burst.When the iteration number is greater than 15,000,the static force of coal mass increases slightly,but there is no obvious rock burst.Based on engineering monitoring,the mining speed of a mine is less than 8 m/d,and the periodic weighting distance is about 17 m;as the mining speed is greater than 10 m/d,and the periodic weighting distance is greater than 20 m;as the mining speed is 3-8 m/d,and the range of high stress in surrounding rock is 48 m;as the advancing speed is 8-12 m/d,and the high-stress range in surrounding rock is 80 m.Moreover,as the mining speed is less than 8 cut cycles,the micro seismic energy is less than 10,000 J;as the mining speed is 12 cut cycles,the microseismic energy is about 20,000 J.In summary,the advancing speed is positively correlated with the micro seismic event;as the mining speed increases,the accumulated elastic energy of surrounding rock is greater,which is easy to cause rock burst.The comprehensive analysis indicates the daily advance speed of the mine is not more than 12 cut cycles.
基金National Key R&D Program of China(2022YFE0105900)National Natural Science Foundation of China(52306179)+1 种基金Science and Technology Innovation Program of Hunan Province(2021RC4006)High Performance Computing Center of Central South University。
文摘The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of adsorbent and catalyst.Herein,we engineered a series of RuNa/γ-Al_(2)O_(3)materials,varying the size of ruthenium from single atoms to clusters/nanoparticles.The coordination environment and structure sensitivity of ruthenium were quantitatively investigated at atomic scale.Our findings reveal that the reduced Ru nanoparticles,approximately 7.1 nm in diameter with a Ru-Ru coordination number of 5.9,exhibit high methane formation activity and selectivity at 340°C.The Ru-Na interfacial sites facilitate CO_(2)migration through a deoxygenation pathway,involving carbonate dissociation,carbonyl formation,and hydrogenation.In-situ experiments and theoretical calculations show that stable carbonyl intermediates on metallic Ru nanoparticles facilitate heterolytic C–O scission and C–H bonding,significantly lowering the energy barrier for activating stored CO_(2).
基金Project(52476095)supported by the National Natural Science Foundation of ChinaProject(kq2506013)supported by Changsha Outstanding Innovative Youth Training Program,China。
文摘The nanofluid-based direct absorption solar collector(NDASC)ensures that solar radiation passing through the tube wall is directly absorbed by the nanofluid,reducing thermal resistance in the energy transfer process.However,further exploration is required to suppress the outward thermal losses from the nanofluid at high temperatures.Herein,this paper proposes a novel NDASC in which the outer surface of the collector tube is covered with functional coatings and a three-dimensional computational fluid dynamics model is established to study the energy flow distributions on the collector within the temperature range of 400-600 K.When the nanofluid’s absorption coefficient reaches 80 m^(-1),the NDASC shows the optimal thermal performance,and the NDASC with local Sn-In_(2)O_(3) coating achieves a 7.8% improvement in thermal efficiency at 400 K compared to the original NDASC.Furthermore,hybrid coatings with Sn In_(2)O_(3)/WTi-Al_(2)O_(3) are explored,and the optimal coverage angles are determined.The NDASC with such coatings shows a 10.22%-17.9% increase in thermal efficiency compared to the original NDASC and a 7.6%-19.5% increase compared to the traditional surface-type solar collectors,demonstrating the effectiveness of the proposed energy flow control strategy for DASCs.
文摘Photovoltaic(PV)power forecasting is essential for balancing energy supply and demand in renewable energy systems.However,the performance of PV panels varies across different technologies due to differences in efficiency and how they process solar radiation.This study evaluates the effectiveness of deep learning models in predicting PV power generation for three panel technologies:Hybrid-Si,Mono-Si,and Poly-Si,across three forecasting horizons:1-step,12-step,and 24-step.Among the tested models,the Convolutional Neural Network—Long Short-Term Memory(CNN-LSTM)architecture exhibited superior performance,particularly for the 24-step horizon,achieving R^(2)=0.9793 and MAE 0.0162 for the Poly-Si array,followed by Mono-Si(R^(2)=0.9768)and Hybrid-Si arrays(R^(2)=0.9769).These findings demonstrate that the CNN-LSTM model can provide accurate and reliable PV power predictions for all studied technologies.By identifying the most suitable predictive model for each panel technology,this study contributes to optimizing PV power forecasting and improving energy management strategies.
基金This research was funded by Natural Science Foundation of Guangdong Province,grant number 2024A1515030130National Natural Science Foundation of China,grant number 42102336.
文摘Amidst the global push for decarbonization,solar-powered Organic Rankine Cycle(SORC)systems are gaining significant attention.The small-scale Organic Rankine Cycle(ORC)systems have enhanced environmental adaptability,improved system flexibility,and achieved diversification of application scenarios.However,the power consumption ratio of the working fluid pump becomes significantly larger relative to the total power output of the system,adversely impacting overall system efficiency.This study introduces an innovative approach by incorporating a vapor-liquid ejector into the ORC system to reduce the pump work consumption within the ORC.The thermoeconomic models for both the traditional ORC and an ORC integrated with a vapor-liquid ejector driven by solar parabolic trough collectors(PTCs)were developed.Key evaluation indicators,such as thermal efficiency,exergy efficiency,specific investment cost,and levelized cost of energy,were employed to compare the SORC with the solar ejector organic Rankine cycle(SEORC).Additionally,the study explores the effects of solar beam radiation intensity,PTC temperature variation,evaporator pinch point temperature difference,and condenser pinch point temperature difference on the thermo-economic performance of both systems.Results demonstrate that SEORC consistently outperforms SORC.Higher solar radiation intensity and increased PTC inlet temperature lead to better system efficiency.Moreover,there is an optimal PTC temperature drop where both thermal and exergy efficiencies are maximized.The influence of evaporator and condenser temperature pinches on system performance is found to be inconsistent.
基金Financial support from National Key R&D Program(2022YFB2404600)Natural Science Foundation of China(Key Project of 52131306)+1 种基金Project on Carbon Emission Peak and Neutrality of Jiangsu Province(BE2022031-4)the Big Data Computing Center of Southeast University are greatly appreciated.
文摘The replacement of non-aqueous organic electrolytes with solid-state electrolytes(SSEs)in solid-state lithium metal batteries(SLMBs)is considered a promising strategy to address the constraints of lithium-ion batteries,especially in terms of energy density and reliability.Nevertheless,few SLMBs can deliver the required cycling performance and long-term stability for practical use,primarily due to suboptimal interface properties.Given the diverse solidification pathways leading to different interface characteristics,it is crucial to pinpoint the source of interface deterioration and develop appropriate remedies.This review focuses on Li|SSE interface issues between lithium metal anode and SSE,discussing recent advancements in the understanding of(electro)chemistry,the impact of defects,and interface evolutions that vary among different SSE species.The state-ofthe-art strategies concerning modified SEI,artificial interlayer,surface architecture,and composite structure are summarized and delved into the internal relationships between interface characteristics and performance enhancements.The current challenges and opportunities in characterizing and modifying the Li|SSE interface are suggested as potential directions for achieving practical SLMBs.
基金supported by the National Natural Science Foundation of China(No.52002170)the Central Guidance Fund Project for Local Scientific and Technological Development in Qinghai Province(No.2024ZY013)+1 种基金the Foundation of Key Laboratory of Flexible Electronics of Zhejiang Province(No.2023FE011)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX24_1635).
文摘Developing fast-charging lithium-ion batteries(LIBs)that feature high energy density is critical for the scalable application of electric vehicles.Iron vanadate(FVO)holds great potential as anode material in fast-charging LIBs because of its high theoretical specific capacity and the high natural abundance of its constituents.However,the capacity of FVO rapidly decays due to its low electrical conductivity.Herein,uniform FVO nanoparticles are grown in situ on ordered mesoporous carbon(CMK-3)support,forming a highly electrically conductive porous network,FVO/CMK-3.The structure of CMK-3 helps prevent agglomeration of FVO particles.The electrically conductive nature of CMK-3 can further enhance the electrical conductivity of FVO/CMK-3 and buffer the volume expansion of FVO particles during cycling processes.As a result,the FVO/CMK-3 displays excellent fast-charging performance of 364.6 mAh·g^(-1)capacity for 2500 cycles at 10 A·g^(-1)(with an ultralow average capacity loss per cycle of 0.003%)through a pseudocapacitive-dominant process.Moreover,the LiCoO_(2)//FVO/CMK-3 full cell achieves a high capacity of 100.2 mAh·g^(-1)and a high capacity retention(96.2%)after 200 cycles.The superior electrochemical performance demonstrates that FVO/CMK-3 is an ideal anode material candidate for fast-charging,stable LIBs with high energy density.
基金supported by the Global Joint Research Program funded by the Pukyong National University(202411790001)the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)+2 种基金funded by the Ministry of Science and ICT(RS-2024-00446825)the Technology Innovation Program(RS-2024-00418815)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)。
文摘Rechargeable magnesium batteries are promising alternatives to traditional lithium batteries because of the high abundance of Mg compounds in earth crust,their low toxicity,and possible favorable properties as electrodes'material.However,Mg metal anodes face several challenges,notably the natively existence of an inactive oxide layer on their surfaces,which reduces their effectiveness.Additionally,interactions of Mg electrodes with electrolyte solutions'components can lead to the formation of insulating surface layers,that can fully block them for ions transport.This review addresses these issues by focusing on surface treatments strategies to enhance electrochemical performance of Mg anodes.It highlights chemical and physical modification techniques to prevent oxidation and inactive-layers formation,as well as their practical implications for MIBs.We also examined the impact of Mg anodes'surface engineering on their electrochemical reversibility and cycling efficiency.Finally,future research directions to improve the performance and commercial viability of magnesium anodes and advance development of high-capacity,safe,and cost-effective energy storage systems based on magnesium electrochemistry are discussed.
基金the technical support for Nano-X from Suzhou Institute of Nano-Tech and NanoBionics,Chinese Academy of Sciences(SINANO)supported by the National Key R&D Program of China(2021YFB3800300)+2 种基金the National Natural Science Foundation of China(22179059,22239002,92372201)the science and technology innovation fund for emission peak and carbon neutrality of Jiangsu province(BK20231512,BK20220034)the Key R&D project funded by department of science and technology of Jiangsu Province(BE2020003)。
文摘Aluminum(Al)exhibits excellent electrical conductivity,mechanical ductility,and good chemical compatibility with high-ionic-conductivity electrolytes.This makes it more suitable as an anode material for all-solid-state lithium batteries(ASSLBs)compared to the overly reactive metallic lithium anode and the mechanically weak silicon anode.This study finds that the pre-lithiated Al anode demonstrates outstanding interfacial stability with the Li_6PS_5Cl(LPSCl)electrolyte,maintaining stable cycling for over 1200 h under conditions of deep charge-discharge.This paper combines the pre-lithiated Al anode with a high-nickel cathode,LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2),paired with the highly ionic conductive LPSCl electrolyte,to design an ASSLB with high energy density and stability.Using anode pre-lithiation techniques,along with dual-reinforcement technology between the electrolyte and the cathode active material,the ASSLB achieves stable cycling for 1000 cycles at a 0.2C rate,with a capacity retention rate of up to 82.2%.At a critical negative-to-positive ratio of 1.1,the battery's specific energy reaches up to 375 Wh kg^(-1),and it maintains over 85.9%of its capacity after 100 charge-discharge cycles.This work provides a new approach and an excellent solution for developing low-cost,high-stability all-solid-state batteries.
基金financially supported by the National Natural Science Foundation of China (No.52101243)the Natural Science Foundation of Guangdong Province (No.2023A1515012619)the Science and Technology Planning Project of Guangzhou (No.202102010373)。
文摘Sodium-ion batteries(SIBs) and potassium-ion batteries(PIBs) have been attracting great attentions and widely been exploited due to the abundant sodium/potassium resources.Hence,the preparation of high-powered anode materials for SIBs/PIBs plays a decisive role for the commercial applications of SIBs/PIBs in the future.Manganese selenides are a class of potential anode materials for SIBs/PIBs because of their small band gap and high electrical conductivity.In this work,MnSe and ReS_(2) core-shell nanowires connecting by polydopamine derived carbon nanotube(MnSe@NC@ReS_(2)) have been successfully synthesized from growing ReS_(2) nanosheets array on the surface of MnSe@NC nano wires,which present excellent Na^(+)/K^(+) storage performance.While applied as SIBs anode,the specific capacity of 300 mAh·g^(-1) was maintwined after 400 cycles at the current density of 1.0 A·g^(-1).Besides,it could also keep 120 mAh·g^(-1) specific capacity after 900 cycles at 1.0 A·g^(-1) for the anode of PIBs.These heterogeneous engineering and one-dimensional-two-dimensional(1D-2D) hybrid strategies could provide an ideal strategy for the synthesis of new hetero-structured anode materials with outstanding battery performance for SIBs and PIBs.
基金financially National Natural Science Foundation of China (22309165)Excellent Youth Foundation of Henan Province (242300421126)+6 种基金Talent Development Funding Project of Shanghai (2021030)Joint Fund of Science and Technology R&D Plan of Henan Province (232301420053)Postdoctoral Science Foundation of China (2023M743170)Key Research Projects of Higher Education Institutions of Henan Province (24A530010, and 23A530002)Key Laboratory of Adv. Mater. of Ministry of Education (Adv Mat2023-17)State Key Laboratory of Inorganic Synthesis & Preparative Chemistry Jilin University (2024-34)Frontier Exploration Projects of Longmen Laboratory of Henan (LMQYTSKT021)。
文摘Zn-based aqueous batteries(ZABs) are gaining widespread popularity due to their low cost and high safety profile. However, the application of ZABs faces significant challenges, such as dendrite growth and parasitic reactions of metallic Zn anodes. Therefore, achieving high-energy–density ZABs necessitates addressing the fundamental thermodynamics and kinetics of Zn anodes. Various strategies are available to mitigate these challenges, with electrolyte additive engineering emerging as one of the most efficient and promising approaches. Despite considerable research in this field, a comprehensive understanding of the intrinsic mechanisms behind the high performance of electrolyte additives remains limited. This review aims to provide a detailed introduction to functional electrolyte additives and thoroughly explore their underlying mechanisms. Additionally, it discusses potential directions and perspectives in additive engineering for ZABs, offering insights into future development and guidelines for achieving high-performance ZABs.
基金supported by the Natural Science Foundation of Hunan Province(No.2024JJ4059)Changsha Outstanding Innovative Youth Training Program(No.kq2306010)+1 种基金National Natural Science Foundation of China(No.52176093)the Central South University Innovation-Driven Research Programme(No.2023CXQD055).
文摘Phase change materials(PCMs)are widely considered as promising energy storage materials for solar/electro-thermal energy storage.Nevertheless,the inherent low thermal/electrical conductivities of most PCMs limit their energy conversion efficiencies,hindering their practical applications.Herein,we fabricate a highly thermally/electrically conductive solid-solid phase change composite(PCC)enabled by forming aligned graphite networks through pressing the mixture of the trimethylolethane and porous expanded graphite(EG).Experiments indicate that both the thermal and electrical conductivities of the PCC increase with increasing mass proportion of the EG because the aligned graphite networks establish highly conductive pathways.Meanwhile,the PCC4 sample with the EG proportion of 20wt%can achieve a high thermal conductivity of 12.82±0.38W·m^(-1)·K^(-1)and a high electrical conductivity of 4.11±0.02S·cm^(-1)in the lengthwise direction.Furthermore,a solar-thermal energy storage device incorporating the PCC4,a solar selective absorber,and a highly transparent glass is developed,which reaches a high solar-thermal efficiency of 77.30±2.71%under 3.0 suns.Moreover,the PCC4 can also reach a high electro-thermal efficiency of 91.62±3.52%at a low voltage of 3.6V,demonstrating its superior electro-thermal storage performance.Finally,stability experiments indicate that PCCs exhibit stabilized performance in prolonged TES operations.Overall,this work offers highly conductive and cost-effective PCCs,which are suitable for large-scale and efficient solar/electro-thermal energy storage.
文摘Chemical leaching of coals would be required to produce cleaner coals for some special applications where physical benefi-ciation may not be effective enough.This would also help in recovering Li and rare earth metals besides in the sequestration of CO_(2).About 20 Indian coals having complexly distributed moderate to high ash contents were sequentially treated with various alkali–acid such as NaOH-HCl,HF,HCl,HCl-HF,and NaOH-HCl-HF leaching.This aimed to establish and design the best stepwise sequential process for the highest degree of demineralisation through a chemical leaching process.Kinetics and process intensification studies were carried out.More than 80%demineralisation of Madhaipur and Neemcha coals was observed using the best sequential treatment designed presently.The repeated stepwise treatment of the alkali and the acid was also studied,which was found to significantly enhance the degree of demineralisation of coals.The integrated process of alkali–acid leaching followed by solvent extraction(Organo-refining)and vice versa of the treated coal was also studied for producing cleaner coals.
基金National Natural Science Foundation of China(No.52476192,No.52106237)Natural Science Foundation of Heilongjiang Province(No.YQ2022E027)。
文摘The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis(PEMWE)emerging as the preeminent pathway for hydrogen production.Despite remarkable advancements in this field,confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable obstacle.This impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles detachment.To address these challenges,we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis system.Compared to constant voltage electrolysis(hydrogen production rate:51.6 m L h^(-1),energy consumption:5.37 kWh Nm-^(3)H_(2)),this strategy(hydrogen production rate:66 m L h^(-1),energy consumption:3.83 kWh Nm-^(3)H_(2))increases the hydrogen production rate by approximately 27%and reduces the energy consumption by about 28%.Furthermore,we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic(PV)system designed for outdoor operation,successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 V.The combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism:pulsed dynamic electrolysis(PDE)dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode surface.As such,PDE-enhanced PEMWE represents a synergistic advancement,concurrently enhancing both the hydrogen generation reaction and associated transport processes.This promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.
基金supported by the National Natural Science Foundation of China(52376103,542B2081).
文摘The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace KOH-catalyzed CO_(2) activation.Comprehensive investigations were conducted on three aspects:physicochemical structure evolution of biochar,mechanistic understanding of trace KOH-facilitated CO_(2) activation processes,and application characteristics for CO_(2) adsorption.Results demonstrate that biochar activated by trace KOH(<10%)and CO_(2) achieves comparable specific surface area(1244.09 m^(2)/g)to that obtained with 100%KOH activation(1425.10 m^(2)/g).The pore structure characteristics(specific surface area and pore volume)are governed by CO and CH4 generated through K-salt catalyzed reactions between CO_(2) and biochar.The optimal CO_(2) adsorption capacities of KBC adsorbent reached 4.70 mmol/g(0℃)and 7.25 mmol/g(25℃),representing the maximum values among comparable carbon adsorbents.The 5%KBC-CO_(2) sample exhibited CO_(2) adsorption capacities of 3.19 and 5.01 mmol/g under respective conditions,attaining current average performance levels.Notably,CO_(2)/N_(2) selectivity(85∶15,volume ratio)reached 64.71 at 0.02 bar with robust cycling stability.Molecular dynamics simulations revealed that oxygen-containing functional groups accelerate CO_(2) adsorption kinetics and enhance micropore storage capacity.This technical route offers simplicity,environmental compatibility,and scalability,providing critical references for large-scale preparation of high-quality carbon materials.
基金supported by the Key Research and Development Projects of Anhui Province(No.202304a05020031).
文摘Lithium-sulfur batteries(LSBs)have attracted widespread attention due to their high theoretical energy density.However,the dissolution of long-chain polysulfides into the electrolyte(the“shuttle effect”)leads to rapid capacity decay.Therefore,finding suitable materials to mitigate the shuttle effect of polysulfides is crucial for enhancing the electrochemical performance of lithium-sulfur batteries.In this study,LSBs’separator is modified with Ni_(3)V_(2)O_(8)nanoparticles@carboxylated carbon nanotubes(Ni_(3)V_(2)O_(8)@CNTs)composite.There are abundant oxygen vacancies in Ni_(3)V_(2)O_(8)@CNTs composite which plays a synergistic effect on shuttle effect.The Ni_(3)V_(2)O_(8)can tightly anchor soluble polysulfides through oxygen vacancies,while the CNTs not only facilitate the transport of ions and electrons but also weaken the migration of polysulfides,limiting shuttle effect.As a result,the cycling stability of LSBs using Ni_(3)V_(2)O_(8)@CNTs-modified separator has been significantly improved(with a capacity decay rate of only 0.0334%after 1500 cycles at 4.0C).This study proposes a strategy to design modified separator for high-performance LSBs.
