In this work,we constructed a three-dimensional electrochemical system(3D-ECO),which included the cathode and anode electrode plates,as well as the screening of three-dimensional particle electrodes and parameter opti...In this work,we constructed a three-dimensional electrochemical system(3D-ECO),which included the cathode and anode electrode plates,as well as the screening of three-dimensional particle electrodes and parameter opti-mization,for the degradation of landfill leachate(LL)containing elevated levels of tetracycline(TC),and explored its mechanism of action.Firstly,titanium-based ruthenium-iridium(Ti/RuO_(2)-IrO_(2)),titanium-based ruthenium-iridium-platinum(Ti/Pt-RuO_(2)-IrO_(2)),and titanium-based tin-antimony(Ti/SnO_(2)-Sb_(2)O_(3))were employed as an-odes in the electrocatalytic oxidation system,with titanium and stainless steel plates serving as cathodes,to construct the optimal two-dimensional electrocatalytic oxidation system(2D-ECO)through cross-comparison ex-periments.Subsequently,using granular activated carbon(GAC),coconut shell biochar(CBC),walnut shell carbon(WBC),and bamboo charcoal(BBC)as particle electrodes,a 3D-ECO system was developed.The influence of var-ious operational parameters on treating TC-containing LL was investigated.The optimal operating parameters obtained from the study was:pH=5,current density of 30 mA/cm^(2),particle dosage of 7 g/L,particle size ranging from 1.70 to 2.00 mm,and electrode spacing of 4 cm.Under these conditions,the COD removal rate of 3D-ECO within three hours was 90.25%,the TC removal rate was 72.41%,and the NH_(3)-N removal rate was 39.52%.The removal of TC followed a pseudo-first-order kinetic model.Additionally,degradation mechanisms were elucidated through electron paramagnetic resonance(EPR)spectrometer and Tert-Butanol(TBA)quenching experiments,indicating that the degradation primarily occurred through a non-radical(1O_(2))pathway.This re-search offers a comprehensive analysis of the simultaneous breakdown of intricate LL matrices and TC,enhancing our comprehension of the degradation processes and underlying mechanisms.展开更多
To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as wel...To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.展开更多
Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-...Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-scale preparation of the“integrated”phosphorus-based precatalyst(FeP-NiP)on nickel foam(NF),which is in situ reconstructed into a highly active and corrosion-resistant(Fe)NiOOH phase for OER.The interaction between phosphate anions(PO_(x)^(y-))and iron ions(Fe^(3+))tunes the electronic structure of the catalytic phase to further enhance OER kinetics.The integrated FeP-NiP@NF electrode exhibits low overpotentials for OER in alkaline water/seawater,requiring only 275/289,320/336,and 349/358 mV to reach 0.1,0.5,and 1.0 A cm^(−2),respectively.The in situ reconstructed PO_(x)^(y-)anion electrostatically repels Cl−in seawater electrolytes,allowing stable operation for over 7 days at 1.0 A cm^(−2) in extreme electrolytes(1.0 M KOH+seawater and 6.0 M KOH+seawater),demonstrating industrial-level stability.This study overcomes the complex synthesis limitations of P-based materials through innovative material design,opening new avenues for electrochemical energy conversion.展开更多
Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effecti...Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effective energy storage systems.Ad-vances in materials science have led to the develop-ment of hybrid nanomaterials,such as combining fil-amentous carbon forms with inorganic nanoparticles,to create new charge and energy transfer processes.Notable materials for electrochemical energy-stor-age applications include MXenes,2D transition met-al carbides,and nitrides,carbon black,carbon aerogels,activated carbon,carbon nanotubes,conducting polymers,carbon fibers,and nanofibers,and graphene,because of their thermal,electrical,and mechanical properties.Carbon materials mixed with conducting polymers,ceramics,metal oxides,transition metal oxides,metal hydroxides,transition metal sulfides,trans-ition metal dichalcogenide,metal sulfides,carbides,nitrides,and biomass materials have received widespread attention due to their remarkable performance,eco-friendliness,cost-effectiveness,and renewability.This article explores the development of carbon-based hybrid materials for future supercapacitors,including electric double-layer capacitors,pseudocapacitors,and hy-brid supercapacitors.It investigates the difficulties that influence structural design,manufacturing(electrospinning,hydro-thermal/solvothermal,template-assisted synthesis,electrodeposition,electrospray,3D printing)techniques and the latest car-bon-based hybrid materials research offer practical solutions for producing high-performance,next-generation supercapacitors.展开更多
With the rapid development of flexible wearable electronics,the demand for stretchable energy storage devices has surged.In this work,a novel gradient-layered architecture was design based on single-pore hollow lignin...With the rapid development of flexible wearable electronics,the demand for stretchable energy storage devices has surged.In this work,a novel gradient-layered architecture was design based on single-pore hollow lignin nanospheres(HLNPs)-intercalated two-dimensional transition metal carbide(Ti_(3)C_(2)T_(x) MXene)for fabricating highly stretchable and durable supercapacitors.By depositing and inserting HLNPs in the MXene layers with a bottom-up decreasing gradient,a multilayered porous MXene structure with smooth ion channels was constructed by reducing the overstacking of MXene lamella.Moreover,the micro-chamber architecture of thin-walled lignin nanospheres effectively extended the contact area between lignin and MXene to improve ion and electron accessibility,thus better utilizing the pseudocapacitive property of lignin.All these strategies effectively enhanced the capacitive performance of the electrodes.In addition,HLNPs,which acted as a protective phase for MXene layer,enhanced mechanical properties of the wrinkled stretchable electrodes by releasing stress through slip and deformation during the stretch-release cycling and greatly improved the structural integrity and capacitive stability of the electrodes.Flexible electrodes and symmetric flexible all-solid-state supercapacitors capable of enduring 600%uniaxial tensile strain were developed with high specific capacitances of 1273 mF cm^(−2)(241 F g^(−1))and 514 mF cm^(−2)(95 F g^(−1)),respectively.Moreover,their capacitances were well preserved after 1000 times of 600%stretch-release cycling.This study showcased new possibilities of incorporating biobased lignin nanospheres in energy storage devices to fabricate stretchable devices leveraging synergies among various two-dimensional nanomaterials.展开更多
High-entropy materials represent a new category of high-performance materials,first proposed in 2004 and extensively investigated by researchers over the past two decades.The definition of high-entropy materials has c...High-entropy materials represent a new category of high-performance materials,first proposed in 2004 and extensively investigated by researchers over the past two decades.The definition of high-entropy materials has continuously evolved.In the last ten years,the discovery of an increasing number of high-entropy materials has led to significant advancements in their utilization in energy storage,electrocatalysis,and related domains,accompanied by a rise in techniques for fabricating high-entropy electrode materials.Recently,the research emphasis has shifted from solely improving the performance of high-entropy materials toward exploring their reaction mechanisms and adopting cleaner preparation approaches.However,the current definition of high-entropy materials remains relatively vague,and the preparation method of high-entropy materials is based on the preparation method of single metal/low-or medium-entropy materials.It should be noted that not all methods applicable to single metal/low-or medium-entropy materials can be directly applied to high-entropy materials.In this review,the definition and development of high-entropy materials are briefly reviewed.Subsequently,the classification of high-entropy electrode materials is presented,followed by a discussion of their applications in energy storage and catalysis from the perspective of synthesis methods.Finally,an evaluation of the advantages and disadvantages of various synthesis methods in the production process of different high-entropy materials is provided,along with a proposal for potential future development directions for high-entropy materials.展开更多
Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poi...Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poisoning of air electrodes,causing substantial degradation in electrochemical performance and compromising the longterm stability of SOCs.This mini-review examines the mechanism of Cr deposition and poisoning in air electrodes under both fuel-cell and electrolysis modes.Furthermore,emphasis is placed on the recent advancements in strategies to mitigate Cr poisoning,offering insights into the rational design and development of active and Cr-tolerant air electrodes for SOCs.展开更多
Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage p...Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.展开更多
Electrospinning technology has emerged as a promising method for fabricating flexible lithium-ion batter-ies(FLIBs)due to its ability to create materials with desir-able properties for energy storage applications.FLIB...Electrospinning technology has emerged as a promising method for fabricating flexible lithium-ion batter-ies(FLIBs)due to its ability to create materials with desir-able properties for energy storage applications.FLIBs,which are foldable and have high energy densities,are be-coming increasingly important as power sources for wear-able devices,flexible electronics,and mobile energy applica-tions.Carbon materials,especially carbon nanofibers,are pivotal in improving the performance of FLIBs by increas-ing electrical conductivity,chemical stability,and surface area,as well as reducing costs.These materials also play a significant role in establishing conducting networks and im-proving structural integrity,which are essential for extend-ing the cycle life and enhancing the safety of the batteries.This review considers the role of electrospinning in the fabrication of critical FLIB components,with a particular emphasis on the integration of carbon materials.It explores strategies to optimize FLIB performance by fine-tuning the electrospinning para-meters,such as electric field strength,spinning rate,solution concentration,and carbonization process.Precise control over fiber properties is crucial for enhancing battery reliability and stability during folding and bending.It also highlights the latest research findings in carbon-based electrode materials,high-performance electrolytes,and separator structures,discussing the practical challenges and opportunities these materials present.It underscores the significant impact of carbon materials on the evolution of FLIBs and their potential to shape future energy storage technologies.展开更多
As global energy demand increases and environmental standards tighten,the development of efficient,eco-friendly energy conversion and storage technologies becomes crucial.Solid oxide cells(SOCs)show great promise beca...As global energy demand increases and environmental standards tighten,the development of efficient,eco-friendly energy conversion and storage technologies becomes crucial.Solid oxide cells(SOCs)show great promise because of their high energy conversion efficiency and wide range of applications.Highentropy materials(HEMs),a novel class of materials comprising several principal elements,have attracted significant interest within the materials science and energy sectors.Their distinctive structural features and adaptable functional properties offer immense potential for innovation across various applications.This review systematically covers the basic concepts,crystal structures,element selection,and major synthesis strategies of HEMs,and explores in detail the specific applications of these materials in SOCs,including its potential as air electrodes,fuel electrodes,electrolytes,and interconnects(including barrier coatings).By analyzing existing studies,this review reveals the significant advantages of HEMs in enhancing the performance,anti-poisoning,and stability of SOCs;highlights the key areas and challenges for future research;and looks into possible future directions.展开更多
In a pulsed plasma thruster,the voltage distribution between the electrodes is a key factor that influences the ionization process.However,few researchers have conducted in-depth studies of this phenomenon in the past...In a pulsed plasma thruster,the voltage distribution between the electrodes is a key factor that influences the ionization process.However,few researchers have conducted in-depth studies of this phenomenon in the past.Reported here are measurements of the voltage distribution between the plates of a parallel-plate pulsed plasma thruster under different discharge voltages,based on which the variations in the total circuit inductance and resistance as well as those between the plates are calculated.The results show that the time-averaged voltage across the plates accounts for 28.7%-50.4%of the capacitor voltage.As the capacitor initial voltage increases from 1250 V to 2000 V,the voltage across the plates rises,but its proportion relative to the capacitor voltage decreases.For every 250 V increase in the capacitor initial voltage,the average voltage proportion across the plates decreases by approximately 2%-3%.Additionally,the voltage proportion decreases gradually from the end near the propellant outward.The voltage distribution ratio between the plates is correlated with the proportions of the resistance and inductance between the plates relative to the total circuit.展开更多
Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-sec...Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-section in the flow channel is normally adopted,the configuration optimization of which could potentially enhance the performance of the electrolyzer.This paper describes the numerical simulation study on the impact of the flow-channel cross-section shapes in the MEA electrolyzer for CO_(2)RR.The results show that wide flow channels with low heights are beneficial to the CO_(2)RR by providing a uniform flow field of CO_(2),especially at high current densities.Moreover,the larger the electrolyzer,the more significant the effect is.This study provides a theoretical basis for the design of high-performance MEA electrolyzers for CO_(2)RR.展开更多
Sodium(Na)and magnesium(Mg)are becoming important for making energy-storage batteries and structural materials.Herein,we develop a liquid-metal-electrode-assisted electrolysis route to producing Na and Mg with low-car...Sodium(Na)and magnesium(Mg)are becoming important for making energy-storage batteries and structural materials.Herein,we develop a liquid-metal-electrode-assisted electrolysis route to producing Na and Mg with low-carbon emissions and no chlorine gas evolution.The clean production stems from the choice of a molten NaCl-Na_(2)CO_(3) electrolyte to prevent chlorine gas evolution,an inert nickel-based anode to produce oxygen,and a liquid metal cathode to make the cathodic product sit at the bottom of the electrolytic cell.We achieve a current efficiency of>90%for the electrolytic production of liquid Na-Sn alloy.Later,Mg-Sn alloy is prepared using the obtained Na-Sn alloy to displace Mg from molten NaCl-MgCl_(2) with a displacement efficiency of>96%.Further,Na and Mg are separated from the electrolytic Na-Sn and displaced Mg-Sn alloys by vacuum distillation with a recovery rate of>92%and Sn can be reused.Using this electrolysisdisplacement-distillation(EDD)approach,we prepare Mg from seawater.The CO_(2)emission of the EDD approach is~20.6 kg CO_(2)per kg Mg,which is less than that of the Australian Magnesium(AM)electrolysis process(~25.0 kg CO_(2)per kg Mg)and less than half that of the Pidgeon process(~45.2 kg CO_(2)per kg Mg).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
This study explores the potential of Michelia champaca wood as a sustainable and locally available precursor for the fabrication of high-performance supercapacitor electrodes.Activated carbons were synthesized through...This study explores the potential of Michelia champaca wood as a sustainable and locally available precursor for the fabrication of high-performance supercapacitor electrodes.Activated carbons were synthesized through single-step carbonization at 400℃ and 500℃(SSC-400℃ and SSC-500℃) and double-step carbonization at 400℃(DSC-400℃),with all samples activated using H_(3)PO_(4).The effects of carbonization stratergy on the structural,morphological,and electrochemical characteristics of the resulting carbon materials were systematically evaluated,using techniques such as BET,SEM,TEM,XRD,Raman scattering,FTIR,CV,GCD and EIS.Among the samples,SSC-400℃ exhibited the best electrochemical performance,achieving a specific capacitance of 292.2 Fg^(-1),an energy density of 6.4 Wh kg^(-1),and a power density of 198.4 W kg^(-1).This superior performance is attributed to its optimized pore structure,improved sur-face functionality and enhanced conductivity.SSC-500℃showed marginally lower performance,whereas,DSC-400℃ displayed the least favorable results,indicating that double-step carbonization process may negatively affect material quality by disrupting the pore network.This work highlights a strong correlation between synthesis methodology and electrochemical efficiency,directly reinforcing the importance of process optimization in electrode material develop-ment.The findings contribute to the broader goal of developing cost-effective,renewable and environmentally friendly energy storage systems.By valorizing biomass waste,the study supports global movements toward green energy technologies and circular carbon economies,offering a viable pathway for sustainable supercapacitor development and practical applications in energy storage devices.展开更多
Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structur...Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structural studies of other physicochemical properties are con-ducted on a series of materials obtained by the sol-gel method with different ratios of Gd and Sm cations.It is documented that changing the x value,and the resulting adjustment of the average ionic radius,have a significant impact on the crystal structure,stability,as well as on the total conductivity and thermomechanical properties of the materials,with the best results obtained for the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)composition.Oxygen electrodes are prepared using the selected compound,allowing to obtain low polarization resistance values,such as 0.086Ω·cm^(2)at 800℃.Systematic studies of electrocatalytic activity are conducted using La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(_(0.2))O_(3−δ)as the electrolyte for all electrodes,and Ce_(0.8)Gd_(0.2)O_(2−δ)electrolyte for the best performing Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes.The electrochemical data are analyzed using the distribution of relaxation times method.Also,the influence of the preparation method of the electrode material is in-ve`stigated using the electrospinning technique.Finally,the performance of the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes is tested in a Ni-YSZ(yttria-stabilized zirconia)anode-supported cell with a Ce_(0.8)Gd_(0.2)O_(2−δ)buffer layer,in the fuel cell and electrolyzer operating modes.With the electrospun electrode,a power density of 462 mW·cm^(−2)is obtained at 700℃,with a current density of ca.0.2 A·cm^(−2)at 1.3 V for the electrolysis at the same temperature,indicating better performance compared to the sol-gel-based electrode.展开更多
Silicon nanowires(SiNWs)have been used in a wide variety of applications over the past few decades due to their excellent material properties.The only drawback is the high production cost of SiNWs.The preparation of S...Silicon nanowires(SiNWs)have been used in a wide variety of applications over the past few decades due to their excellent material properties.The only drawback is the high production cost of SiNWs.The preparation of SiNWs from photovoltaic waste silicon(WSi)powders,which are high-volume industrial wastes,not only avoids the secondary energy consumption and environmental pollution caused by complicated recycling methods,but also realizes its high-value utilization.Herein,we present a method to rapidly convert photovoltaic WSi powders into SiNWs products.The flash heating and quenching provided by carbothermal shock induce the production of free silicon atoms from the WSi powders,which are rapidly reorganized and assembled into SiNWs during the vapor-phase process.This method allows for the one-step composite of SiNWs and carbon cloth(CC)and the formation of SiC at the interface of the silicon(Si)and carbon(C)contact to create a stable chemical connection.The obtained SiNWs-CC(SiNWs@CC)composites can be directly used as lithium anodes,exhibiting high initial coulombic efficiency(86.4%)and stable cycling specific capacity(2437.4 mA h g^(-1)at 0.5 A g^(-1)after 165 cycles).In addition,various SiNWs@C composite electrodes are easily prepared using this method.展开更多
Graphite-silicon species(Gr-Si)hybrid anodes have merged as potential candidates for high-energy lithium-ion batteries(LIBs),yet long been plagued by rapid capacity fading due to their unstable mechano-electrochemistr...Graphite-silicon species(Gr-Si)hybrid anodes have merged as potential candidates for high-energy lithium-ion batteries(LIBs),yet long been plagued by rapid capacity fading due to their unstable mechano-electrochemistry.The dominant approach to enhance electrochemical stability of the Gr-Si hybrid anodes typically involves the optimization of the electrode material structures and the employment of low active Si species content in electrode(<10 wt%in most instances).However,the electrode structure design,a factor of equal importance in determining the electrochemical performance of Gr-Si hybrid anodes,has received scant attention.In this study,three Gr-Si hybrid anodes with the identical material composition but distinct electrode structures are designed to investigate the mechanoelectrochemistry of the electrodes.It is revealed that the substantial volume change of Si species particles in Gr-Si hybrid anodes led to the local lattice stress of Gr at their contact interface during the charge/discharge processes,thereby increasing thermodynamic and kinetic barrier of Li-ion migration.Furthermore,the huge disparity in volume change of Si species and Gr particles trigger the separate agglomeration of these two materials,resulting in a considerable electrode volume change and increased electrochemical resistance.An advanced Gr/Si hybrid anode with upper Gr and lower Si species layer structure design addresses the above challenges using photovoltaic waste silicon sources under high Si species content(17 wt%)and areal capacity(2.0 mA h cm^(-2))in Ah-level full pouch cells with a low negative/positive(N/P)ratio of 1.09.The cell shows stable cycling for 100 cycles at 0.3 C with an impressively low capacity decay rate of 0.0546%per cycle,outperforming most reported Gr-Si hybrid anodes.展开更多
Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities.Unfortunately,traditional slurry-casting electrodes induce high-tortuous io...Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities.Unfortunately,traditional slurry-casting electrodes induce high-tortuous ionic diffusion routes that directly depress the capacitance with a thickening design.To overcome this,a novel 3D low-tortuosity,self-supporting,wood-structured ultrathick electrode(NiMoN@WC,a thickness of~1400 mm)with hierarchical porosity and artificial array-distributed small holes was constructed via anchoring bimetallic nitrides into the monolithic wood carbons.Accompanying the embedded NiMoN nanoclusters with well-designed geometric and electronic structure,the vertically low-tortuous channels,enlarged specific surface area and pore volume,superhydrophilic interface,and excellent charge conductivities,a superior capacitance of NiMoN@WC thick electrodes(~5350 mF cm^(-2)and 184.5 F g^(-1))is achieved without the structural deformation.In especial,monolithic wood carbons with gradient porous network not only function as the high-flux matrices to ameliorate the NiMoN loading via cell wall engineering but also allow fully-exposed electroactive substance and efficient current collection,thereby deliver an acceptable rate capability over 75%retention even at a high sweep rate of 20 mA cm^(-2).Additionally,an asymmetric NiMoN@WC//WC supercapacitor with an available working voltage of 1.0-1.8 V is assembled to demonstrate a maximum energy density of~2.04 mWh cm^(-2)(17.4 Wh kg^(-1))at a power density of 1620 mW cm^(-2),along with a decent long-term lifespan over 10,000 charging-discharging cycles.As a guideline,the rational design of wood ultrathick electrode with nanostructured transition metal nitrides sketch a promising blueprint for alleviating global energy scarcity while expanding carbon-neutral technologies.展开更多
Fully implanted brain-computer interfaces(BCIs)are preferred as they eliminate signal degradation caused by interference and absorption in external tissues,a common issue in non-fully implanted systems.To optimize the...Fully implanted brain-computer interfaces(BCIs)are preferred as they eliminate signal degradation caused by interference and absorption in external tissues,a common issue in non-fully implanted systems.To optimize the design of electroencephalography electrodes in fully implanted BCI systems,this study investigates the penetration and absorption characteristics of microwave signals in human brain tissue at different frequencies.Electromagnetic simulations are used to analyze the power density distribution and specific absorption rate(SAR)of signals at various frequen-cies.The results indicate that lower-frequency signals offer advantages in terms of power density and attenuation coeffi-cients.However,SAR-normalized analysis,which considers both power density and electromagnetic radiation hazards,shows that higher-frequency signals perform better at superficial to intermediate depths.Specifically,at a depth of 2 mm beneath the cortex,the power density of a 6.5 GHz signal is 247.83%higher than that of a 0.4 GHz signal.At a depth of 5 mm,the power density of a 3.5 GHz signal exceeds that of a 0.4 GHz signal by 224.16%.The findings suggest that 6.5 GHz is optimal for electrodes at a depth of 2 mm,3.5 GHz for 5 mm,2.45 GHz for depths of 15-20 mm,and 1.8 GHz for 25 mm.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42477406 and 51878617)the Horizontal Scientific Research Project(No.KYY-HX-20220803)the Engineering Research Center of Ministry of Education for Renewable Energy Infrastructure Construction Technology.
文摘In this work,we constructed a three-dimensional electrochemical system(3D-ECO),which included the cathode and anode electrode plates,as well as the screening of three-dimensional particle electrodes and parameter opti-mization,for the degradation of landfill leachate(LL)containing elevated levels of tetracycline(TC),and explored its mechanism of action.Firstly,titanium-based ruthenium-iridium(Ti/RuO_(2)-IrO_(2)),titanium-based ruthenium-iridium-platinum(Ti/Pt-RuO_(2)-IrO_(2)),and titanium-based tin-antimony(Ti/SnO_(2)-Sb_(2)O_(3))were employed as an-odes in the electrocatalytic oxidation system,with titanium and stainless steel plates serving as cathodes,to construct the optimal two-dimensional electrocatalytic oxidation system(2D-ECO)through cross-comparison ex-periments.Subsequently,using granular activated carbon(GAC),coconut shell biochar(CBC),walnut shell carbon(WBC),and bamboo charcoal(BBC)as particle electrodes,a 3D-ECO system was developed.The influence of var-ious operational parameters on treating TC-containing LL was investigated.The optimal operating parameters obtained from the study was:pH=5,current density of 30 mA/cm^(2),particle dosage of 7 g/L,particle size ranging from 1.70 to 2.00 mm,and electrode spacing of 4 cm.Under these conditions,the COD removal rate of 3D-ECO within three hours was 90.25%,the TC removal rate was 72.41%,and the NH_(3)-N removal rate was 39.52%.The removal of TC followed a pseudo-first-order kinetic model.Additionally,degradation mechanisms were elucidated through electron paramagnetic resonance(EPR)spectrometer and Tert-Butanol(TBA)quenching experiments,indicating that the degradation primarily occurred through a non-radical(1O_(2))pathway.This re-search offers a comprehensive analysis of the simultaneous breakdown of intricate LL matrices and TC,enhancing our comprehension of the degradation processes and underlying mechanisms.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.NRF-2021M3H4A1A02048529)the Ministry of Trade,Industry and Energy(MOTIE)of the Korean government under grant No.RS-2022-00155854support from the DGIST Supercomputing and Big Data Center.
文摘To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.
基金funding support from Natural Science Foundation of Shanghai(Grant No.23ZR1443900)the National Natural Science Foundation of China(Grant Nos.22178309,22476131 and 22176127)。
文摘Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-scale preparation of the“integrated”phosphorus-based precatalyst(FeP-NiP)on nickel foam(NF),which is in situ reconstructed into a highly active and corrosion-resistant(Fe)NiOOH phase for OER.The interaction between phosphate anions(PO_(x)^(y-))and iron ions(Fe^(3+))tunes the electronic structure of the catalytic phase to further enhance OER kinetics.The integrated FeP-NiP@NF electrode exhibits low overpotentials for OER in alkaline water/seawater,requiring only 275/289,320/336,and 349/358 mV to reach 0.1,0.5,and 1.0 A cm^(−2),respectively.The in situ reconstructed PO_(x)^(y-)anion electrostatically repels Cl−in seawater electrolytes,allowing stable operation for over 7 days at 1.0 A cm^(−2) in extreme electrolytes(1.0 M KOH+seawater and 6.0 M KOH+seawater),demonstrating industrial-level stability.This study overcomes the complex synthesis limitations of P-based materials through innovative material design,opening new avenues for electrochemical energy conversion.
文摘Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effective energy storage systems.Ad-vances in materials science have led to the develop-ment of hybrid nanomaterials,such as combining fil-amentous carbon forms with inorganic nanoparticles,to create new charge and energy transfer processes.Notable materials for electrochemical energy-stor-age applications include MXenes,2D transition met-al carbides,and nitrides,carbon black,carbon aerogels,activated carbon,carbon nanotubes,conducting polymers,carbon fibers,and nanofibers,and graphene,because of their thermal,electrical,and mechanical properties.Carbon materials mixed with conducting polymers,ceramics,metal oxides,transition metal oxides,metal hydroxides,transition metal sulfides,trans-ition metal dichalcogenide,metal sulfides,carbides,nitrides,and biomass materials have received widespread attention due to their remarkable performance,eco-friendliness,cost-effectiveness,and renewability.This article explores the development of carbon-based hybrid materials for future supercapacitors,including electric double-layer capacitors,pseudocapacitors,and hy-brid supercapacitors.It investigates the difficulties that influence structural design,manufacturing(electrospinning,hydro-thermal/solvothermal,template-assisted synthesis,electrodeposition,electrospray,3D printing)techniques and the latest car-bon-based hybrid materials research offer practical solutions for producing high-performance,next-generation supercapacitors.
基金supported by Natural Science and Engineering Research Council of Canada(RGPIN-2017-06737)Canada Research Chairs program,the National Key Research and Development Program of China(2017YFD0601005,2022YFD0904201)+1 种基金the National Natural Science Foundation of China(51203075)the China Scholarship Council(Grant No.CSC202208320361).
文摘With the rapid development of flexible wearable electronics,the demand for stretchable energy storage devices has surged.In this work,a novel gradient-layered architecture was design based on single-pore hollow lignin nanospheres(HLNPs)-intercalated two-dimensional transition metal carbide(Ti_(3)C_(2)T_(x) MXene)for fabricating highly stretchable and durable supercapacitors.By depositing and inserting HLNPs in the MXene layers with a bottom-up decreasing gradient,a multilayered porous MXene structure with smooth ion channels was constructed by reducing the overstacking of MXene lamella.Moreover,the micro-chamber architecture of thin-walled lignin nanospheres effectively extended the contact area between lignin and MXene to improve ion and electron accessibility,thus better utilizing the pseudocapacitive property of lignin.All these strategies effectively enhanced the capacitive performance of the electrodes.In addition,HLNPs,which acted as a protective phase for MXene layer,enhanced mechanical properties of the wrinkled stretchable electrodes by releasing stress through slip and deformation during the stretch-release cycling and greatly improved the structural integrity and capacitive stability of the electrodes.Flexible electrodes and symmetric flexible all-solid-state supercapacitors capable of enduring 600%uniaxial tensile strain were developed with high specific capacitances of 1273 mF cm^(−2)(241 F g^(−1))and 514 mF cm^(−2)(95 F g^(−1)),respectively.Moreover,their capacitances were well preserved after 1000 times of 600%stretch-release cycling.This study showcased new possibilities of incorporating biobased lignin nanospheres in energy storage devices to fabricate stretchable devices leveraging synergies among various two-dimensional nanomaterials.
基金supported by the National Natural Science Foundation of China(22378431,52004338,51622406,21673298)Hunan Provincial Natural Science Foundation(2023JJ40210,2022JJ20075)+3 种基金the Science and Technology Innovation Program of Hunan Province(2023RC3259)the Key R&D plan of Hunan Province(2024JK2096)Scientifc Research Fund of Hunan Provincial Education Department(23B0699)Central South University Innovation-Driven Research Programme(2023CXQD008).
文摘High-entropy materials represent a new category of high-performance materials,first proposed in 2004 and extensively investigated by researchers over the past two decades.The definition of high-entropy materials has continuously evolved.In the last ten years,the discovery of an increasing number of high-entropy materials has led to significant advancements in their utilization in energy storage,electrocatalysis,and related domains,accompanied by a rise in techniques for fabricating high-entropy electrode materials.Recently,the research emphasis has shifted from solely improving the performance of high-entropy materials toward exploring their reaction mechanisms and adopting cleaner preparation approaches.However,the current definition of high-entropy materials remains relatively vague,and the preparation method of high-entropy materials is based on the preparation method of single metal/low-or medium-entropy materials.It should be noted that not all methods applicable to single metal/low-or medium-entropy materials can be directly applied to high-entropy materials.In this review,the definition and development of high-entropy materials are briefly reviewed.Subsequently,the classification of high-entropy electrode materials is presented,followed by a discussion of their applications in energy storage and catalysis from the perspective of synthesis methods.Finally,an evaluation of the advantages and disadvantages of various synthesis methods in the production process of different high-entropy materials is provided,along with a proposal for potential future development directions for high-entropy materials.
基金supported by National Natural Science Foundation of China(22279018)National Natural Science Foundation of China(22005055)Natural Science Foundation of Fujian Province(2022J01085).
文摘Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poisoning of air electrodes,causing substantial degradation in electrochemical performance and compromising the longterm stability of SOCs.This mini-review examines the mechanism of Cr deposition and poisoning in air electrodes under both fuel-cell and electrolysis modes.Furthermore,emphasis is placed on the recent advancements in strategies to mitigate Cr poisoning,offering insights into the rational design and development of active and Cr-tolerant air electrodes for SOCs.
基金supported by Fundamental Research Funds for the Central Universities(2023KYJD1008)the Science Research Projects of the Anhui Higher Education Institutions of China(2022AH051582).
文摘Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.
文摘Electrospinning technology has emerged as a promising method for fabricating flexible lithium-ion batter-ies(FLIBs)due to its ability to create materials with desir-able properties for energy storage applications.FLIBs,which are foldable and have high energy densities,are be-coming increasingly important as power sources for wear-able devices,flexible electronics,and mobile energy applica-tions.Carbon materials,especially carbon nanofibers,are pivotal in improving the performance of FLIBs by increas-ing electrical conductivity,chemical stability,and surface area,as well as reducing costs.These materials also play a significant role in establishing conducting networks and im-proving structural integrity,which are essential for extend-ing the cycle life and enhancing the safety of the batteries.This review considers the role of electrospinning in the fabrication of critical FLIB components,with a particular emphasis on the integration of carbon materials.It explores strategies to optimize FLIB performance by fine-tuning the electrospinning para-meters,such as electric field strength,spinning rate,solution concentration,and carbonization process.Precise control over fiber properties is crucial for enhancing battery reliability and stability during folding and bending.It also highlights the latest research findings in carbon-based electrode materials,high-performance electrolytes,and separator structures,discussing the practical challenges and opportunities these materials present.It underscores the significant impact of carbon materials on the evolution of FLIBs and their potential to shape future energy storage technologies.
基金supported by the National Key R&D Program of China(2022YFB4004000)National Natural Science Foundation of China(U24A20542,52472210,22279057)+3 种基金Natural Science Foundation of Jiangsu Province(BK20221312)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_1465)Cultivation Program for the Excellent Doctoral Dissertation of Nanjing Tech University(2023-09)the grant of Hydrogen Energy Laboratory(No.FEUZ-2024-0009)。
文摘As global energy demand increases and environmental standards tighten,the development of efficient,eco-friendly energy conversion and storage technologies becomes crucial.Solid oxide cells(SOCs)show great promise because of their high energy conversion efficiency and wide range of applications.Highentropy materials(HEMs),a novel class of materials comprising several principal elements,have attracted significant interest within the materials science and energy sectors.Their distinctive structural features and adaptable functional properties offer immense potential for innovation across various applications.This review systematically covers the basic concepts,crystal structures,element selection,and major synthesis strategies of HEMs,and explores in detail the specific applications of these materials in SOCs,including its potential as air electrodes,fuel electrodes,electrolytes,and interconnects(including barrier coatings).By analyzing existing studies,this review reveals the significant advantages of HEMs in enhancing the performance,anti-poisoning,and stability of SOCs;highlights the key areas and challenges for future research;and looks into possible future directions.
基金supported by the Beijing Natural Science Foundation(No.QY24166).
文摘In a pulsed plasma thruster,the voltage distribution between the electrodes is a key factor that influences the ionization process.However,few researchers have conducted in-depth studies of this phenomenon in the past.Reported here are measurements of the voltage distribution between the plates of a parallel-plate pulsed plasma thruster under different discharge voltages,based on which the variations in the total circuit inductance and resistance as well as those between the plates are calculated.The results show that the time-averaged voltage across the plates accounts for 28.7%-50.4%of the capacitor voltage.As the capacitor initial voltage increases from 1250 V to 2000 V,the voltage across the plates rises,but its proportion relative to the capacitor voltage decreases.For every 250 V increase in the capacitor initial voltage,the average voltage proportion across the plates decreases by approximately 2%-3%.Additionally,the voltage proportion decreases gradually from the end near the propellant outward.The voltage distribution ratio between the plates is correlated with the proportions of the resistance and inductance between the plates relative to the total circuit.
基金the National Key R&D Program of China(No.2021YFA1501503)the National Natural Science Foundation of China(Nos.22250008,22121004,22108197)+3 种基金the Haihe Laboratory of Sustainable Chemical Transformations(No.CYZC202107)the Natural Science Foundation of Tianjin City(No.21JCZXJC00060)the Program of Introducing Talents of Discipline to Universities(No.BP0618007)the Xplorer Prize for financial support。
文摘Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-section in the flow channel is normally adopted,the configuration optimization of which could potentially enhance the performance of the electrolyzer.This paper describes the numerical simulation study on the impact of the flow-channel cross-section shapes in the MEA electrolyzer for CO_(2)RR.The results show that wide flow channels with low heights are beneficial to the CO_(2)RR by providing a uniform flow field of CO_(2),especially at high current densities.Moreover,the larger the electrolyzer,the more significant the effect is.This study provides a theoretical basis for the design of high-performance MEA electrolyzers for CO_(2)RR.
基金support from the National Natural Science Foundation of China(No’s.U22B2071,51874211,52031008)the Chilwee Group(CWDY-ZH-YJY-202101-001).
文摘Sodium(Na)and magnesium(Mg)are becoming important for making energy-storage batteries and structural materials.Herein,we develop a liquid-metal-electrode-assisted electrolysis route to producing Na and Mg with low-carbon emissions and no chlorine gas evolution.The clean production stems from the choice of a molten NaCl-Na_(2)CO_(3) electrolyte to prevent chlorine gas evolution,an inert nickel-based anode to produce oxygen,and a liquid metal cathode to make the cathodic product sit at the bottom of the electrolytic cell.We achieve a current efficiency of>90%for the electrolytic production of liquid Na-Sn alloy.Later,Mg-Sn alloy is prepared using the obtained Na-Sn alloy to displace Mg from molten NaCl-MgCl_(2) with a displacement efficiency of>96%.Further,Na and Mg are separated from the electrolytic Na-Sn and displaced Mg-Sn alloys by vacuum distillation with a recovery rate of>92%and Sn can be reused.Using this electrolysisdisplacement-distillation(EDD)approach,we prepare Mg from seawater.The CO_(2)emission of the EDD approach is~20.6 kg CO_(2)per kg Mg,which is less than that of the Australian Magnesium(AM)electrolysis process(~25.0 kg CO_(2)per kg Mg)and less than half that of the Pidgeon process(~45.2 kg CO_(2)per kg Mg).
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This study explores the potential of Michelia champaca wood as a sustainable and locally available precursor for the fabrication of high-performance supercapacitor electrodes.Activated carbons were synthesized through single-step carbonization at 400℃ and 500℃(SSC-400℃ and SSC-500℃) and double-step carbonization at 400℃(DSC-400℃),with all samples activated using H_(3)PO_(4).The effects of carbonization stratergy on the structural,morphological,and electrochemical characteristics of the resulting carbon materials were systematically evaluated,using techniques such as BET,SEM,TEM,XRD,Raman scattering,FTIR,CV,GCD and EIS.Among the samples,SSC-400℃ exhibited the best electrochemical performance,achieving a specific capacitance of 292.2 Fg^(-1),an energy density of 6.4 Wh kg^(-1),and a power density of 198.4 W kg^(-1).This superior performance is attributed to its optimized pore structure,improved sur-face functionality and enhanced conductivity.SSC-500℃showed marginally lower performance,whereas,DSC-400℃ displayed the least favorable results,indicating that double-step carbonization process may negatively affect material quality by disrupting the pore network.This work highlights a strong correlation between synthesis methodology and electrochemical efficiency,directly reinforcing the importance of process optimization in electrode material develop-ment.The findings contribute to the broader goal of developing cost-effective,renewable and environmentally friendly energy storage systems.By valorizing biomass waste,the study supports global movements toward green energy technologies and circular carbon economies,offering a viable pathway for sustainable supercapacitor development and practical applications in energy storage devices.
基金funded by the National Science Centre,Poland,on the basis of the decision number UMO-2020/37/B/ST8/02097supported by the program“Excellence Initiative-Research University”for the AGH University of Krakow(IDUB AGH,No.501.696.7996,Action 4,ID 9880).
文摘Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structural studies of other physicochemical properties are con-ducted on a series of materials obtained by the sol-gel method with different ratios of Gd and Sm cations.It is documented that changing the x value,and the resulting adjustment of the average ionic radius,have a significant impact on the crystal structure,stability,as well as on the total conductivity and thermomechanical properties of the materials,with the best results obtained for the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)composition.Oxygen electrodes are prepared using the selected compound,allowing to obtain low polarization resistance values,such as 0.086Ω·cm^(2)at 800℃.Systematic studies of electrocatalytic activity are conducted using La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(_(0.2))O_(3−δ)as the electrolyte for all electrodes,and Ce_(0.8)Gd_(0.2)O_(2−δ)electrolyte for the best performing Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes.The electrochemical data are analyzed using the distribution of relaxation times method.Also,the influence of the preparation method of the electrode material is in-ve`stigated using the electrospinning technique.Finally,the performance of the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes is tested in a Ni-YSZ(yttria-stabilized zirconia)anode-supported cell with a Ce_(0.8)Gd_(0.2)O_(2−δ)buffer layer,in the fuel cell and electrolyzer operating modes.With the electrospun electrode,a power density of 462 mW·cm^(−2)is obtained at 700℃,with a current density of ca.0.2 A·cm^(−2)at 1.3 V for the electrolysis at the same temperature,indicating better performance compared to the sol-gel-based electrode.
基金partially funded by the National Natural Science Foundation of China(52074255,52274412)。
文摘Silicon nanowires(SiNWs)have been used in a wide variety of applications over the past few decades due to their excellent material properties.The only drawback is the high production cost of SiNWs.The preparation of SiNWs from photovoltaic waste silicon(WSi)powders,which are high-volume industrial wastes,not only avoids the secondary energy consumption and environmental pollution caused by complicated recycling methods,but also realizes its high-value utilization.Herein,we present a method to rapidly convert photovoltaic WSi powders into SiNWs products.The flash heating and quenching provided by carbothermal shock induce the production of free silicon atoms from the WSi powders,which are rapidly reorganized and assembled into SiNWs during the vapor-phase process.This method allows for the one-step composite of SiNWs and carbon cloth(CC)and the formation of SiC at the interface of the silicon(Si)and carbon(C)contact to create a stable chemical connection.The obtained SiNWs-CC(SiNWs@CC)composites can be directly used as lithium anodes,exhibiting high initial coulombic efficiency(86.4%)and stable cycling specific capacity(2437.4 mA h g^(-1)at 0.5 A g^(-1)after 165 cycles).In addition,various SiNWs@C composite electrodes are easily prepared using this method.
基金the financial support by the National Natural Science Foundation of China(52072137)the National Natural Science Foundation of China(22205068)the"CUG Scholar"Scientific Research Funds at China University of Geosciences(Wuhan)(2022118)。
文摘Graphite-silicon species(Gr-Si)hybrid anodes have merged as potential candidates for high-energy lithium-ion batteries(LIBs),yet long been plagued by rapid capacity fading due to their unstable mechano-electrochemistry.The dominant approach to enhance electrochemical stability of the Gr-Si hybrid anodes typically involves the optimization of the electrode material structures and the employment of low active Si species content in electrode(<10 wt%in most instances).However,the electrode structure design,a factor of equal importance in determining the electrochemical performance of Gr-Si hybrid anodes,has received scant attention.In this study,three Gr-Si hybrid anodes with the identical material composition but distinct electrode structures are designed to investigate the mechanoelectrochemistry of the electrodes.It is revealed that the substantial volume change of Si species particles in Gr-Si hybrid anodes led to the local lattice stress of Gr at their contact interface during the charge/discharge processes,thereby increasing thermodynamic and kinetic barrier of Li-ion migration.Furthermore,the huge disparity in volume change of Si species and Gr particles trigger the separate agglomeration of these two materials,resulting in a considerable electrode volume change and increased electrochemical resistance.An advanced Gr/Si hybrid anode with upper Gr and lower Si species layer structure design addresses the above challenges using photovoltaic waste silicon sources under high Si species content(17 wt%)and areal capacity(2.0 mA h cm^(-2))in Ah-level full pouch cells with a low negative/positive(N/P)ratio of 1.09.The cell shows stable cycling for 100 cycles at 0.3 C with an impressively low capacity decay rate of 0.0546%per cycle,outperforming most reported Gr-Si hybrid anodes.
基金support from the National Natural Science Foundation of China(32171728)Wuhan Knowledge Innovation Project(2022020801020312).
文摘Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities.Unfortunately,traditional slurry-casting electrodes induce high-tortuous ionic diffusion routes that directly depress the capacitance with a thickening design.To overcome this,a novel 3D low-tortuosity,self-supporting,wood-structured ultrathick electrode(NiMoN@WC,a thickness of~1400 mm)with hierarchical porosity and artificial array-distributed small holes was constructed via anchoring bimetallic nitrides into the monolithic wood carbons.Accompanying the embedded NiMoN nanoclusters with well-designed geometric and electronic structure,the vertically low-tortuous channels,enlarged specific surface area and pore volume,superhydrophilic interface,and excellent charge conductivities,a superior capacitance of NiMoN@WC thick electrodes(~5350 mF cm^(-2)and 184.5 F g^(-1))is achieved without the structural deformation.In especial,monolithic wood carbons with gradient porous network not only function as the high-flux matrices to ameliorate the NiMoN loading via cell wall engineering but also allow fully-exposed electroactive substance and efficient current collection,thereby deliver an acceptable rate capability over 75%retention even at a high sweep rate of 20 mA cm^(-2).Additionally,an asymmetric NiMoN@WC//WC supercapacitor with an available working voltage of 1.0-1.8 V is assembled to demonstrate a maximum energy density of~2.04 mWh cm^(-2)(17.4 Wh kg^(-1))at a power density of 1620 mW cm^(-2),along with a decent long-term lifespan over 10,000 charging-discharging cycles.As a guideline,the rational design of wood ultrathick electrode with nanostructured transition metal nitrides sketch a promising blueprint for alleviating global energy scarcity while expanding carbon-neutral technologies.
基金The Open Project of State Key Laboratory of Smart Grid Protection and Operation Control in 2022(No.SGNR0000KJJS2302150).
文摘Fully implanted brain-computer interfaces(BCIs)are preferred as they eliminate signal degradation caused by interference and absorption in external tissues,a common issue in non-fully implanted systems.To optimize the design of electroencephalography electrodes in fully implanted BCI systems,this study investigates the penetration and absorption characteristics of microwave signals in human brain tissue at different frequencies.Electromagnetic simulations are used to analyze the power density distribution and specific absorption rate(SAR)of signals at various frequen-cies.The results indicate that lower-frequency signals offer advantages in terms of power density and attenuation coeffi-cients.However,SAR-normalized analysis,which considers both power density and electromagnetic radiation hazards,shows that higher-frequency signals perform better at superficial to intermediate depths.Specifically,at a depth of 2 mm beneath the cortex,the power density of a 6.5 GHz signal is 247.83%higher than that of a 0.4 GHz signal.At a depth of 5 mm,the power density of a 3.5 GHz signal exceeds that of a 0.4 GHz signal by 224.16%.The findings suggest that 6.5 GHz is optimal for electrodes at a depth of 2 mm,3.5 GHz for 5 mm,2.45 GHz for depths of 15-20 mm,and 1.8 GHz for 25 mm.
