Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of va...Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.展开更多
Metals,indispensable since the Bronze Age,remain pivotal in modern technologies due to their exceptional properties and versatility.Beyond traditional machining,advanced nano/micro-machining techniques enable the fabr...Metals,indispensable since the Bronze Age,remain pivotal in modern technologies due to their exceptional properties and versatility.Beyond traditional machining,advanced nano/micro-machining techniques enable the fabrication of metallic nano/micro structures with high precision in shape,size,and pattern.These structures endow flexible electrodes with outstanding electrical,mechanical,optical,and electrochemical performance,enabling growing applications in flexible optoelectronics,epidermal electronics,energy harvesting,and biochemical sensing.This review provides a comprehensive overview of the fabrication strategies for flexible electrodes made from metal meshes,metal nanowires,and liquid metals.The current advancements,existing challenges,and emerging technologies are systematically discussed.Furthermore,the progression toward ultra-thin,soft epidermal electrodes is explored,with an emphasis on novel in situ and transfer fabrication methods.We examine the underlying mechanisms,performance indicators,and their integration for on-skin applications,including bioelectric sensing,electrical stimulation,and energy harvesting.Finally,we highlight the remaining challenges in performance improvement and industrialization of flexible and epidermal electrodes,along with future opportunities for integrating multimodal systems and leveraging artificial intelligence to enhance their functionalities.展开更多
Driven by the trend of device miniaturization and high-density integration,the interaction between adjacent electrodes has become a critical factor affecting the interfacial reliability of thermoelectric(TE)structures...Driven by the trend of device miniaturization and high-density integration,the interaction between adjacent electrodes has become a critical factor affecting the interfacial reliability of thermoelectric(TE)structures.This study investigates the influence of adjoining electrode interactions on the interfacial response of a multi-electrode/TE substrate structure,including interfacial stresses and stress intensity factors at the electrode ends.To solve the corresponding boundary-value problem,the Fourier transforms are adopted to derive a governing integro-differential equation for the interfacial shear stress in multi-electrode systems,incorporating the TE effects as generalized forces on the right-hand side.The results show that both the interfacial tension and transverse stress in the electrodes are significantly affected by the presence of adjacent electrodes.The interaction between neighboring electrodes diminishes as their spacing increases or when an adhesive interlayer is introduced.Furthermore,the softer and thinner electrodes,the softer and thicker adhesive interlayer,and the smaller TE loads are found to be beneficial for improving the interfacial performance.These findings may contribute to the accurate measurement in surface sensors and layout design of multi-point health monitoring systems for TE structures.展开更多
α-MnO_(2) is a promising,inexpensive,and readily producible catalyst for the oxygen reduction reaction(ORR)in alkaline media,but its application is limited by low electronic conductivity.In this study,we enhance the ...α-MnO_(2) is a promising,inexpensive,and readily producible catalyst for the oxygen reduction reaction(ORR)in alkaline media,but its application is limited by low electronic conductivity.In this study,we enhance the performance ofα-MnO_(2) electrodes by systematically varying theα-MnO_(2)-to-Vulcan ratio within the catalyst layer.Electrodes are evaluated in a gas diffusion electrode(GDE)half-cell,where an optimized catalyst layer composition leads to significantly improved ORR performance.By finetuning both theα-MnO_(2)-to-Vulcan ratio and theα-MnO_(2) loading,the electrode outperforms a commercial MnO_(2)-based electrode and approaches the performance of the Pt/C benchmark.The improvement is attributed to the presence of a three-dimensional(3D)Vulcan network electronically connecting catalytically activeα-MnO_(2) sites with the substrate.Additionally,the optimized electrodes are employed in a prototype Al-O_(2) flow cell.Under constant oxygen flow,power densities exceed 250 mW cm^(-2),which is significantly higher than that of conventional Al-air batteries.Electrochemical impedance spectroscopy combined with distribution of relaxation times(DRT)analysis enables the separation of anode and cathode charge transfer impedances without the need for an additional reference electrode.The analysis reveals that the anode contributes more than twice as much impedance as the cathode,highlighting the need for further anode optimization.This work demonstrates a transferable approach for catalyst layer screening under technically relevant conditions in the GDE half-cell.Subsequent measurements in an Al-O_(2) flow cell validate the approach.The methodology is widely applicable to the development of advanced electrodes for a variety of metal-air battery technologies.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
Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is a highly successful conductive polymer utilized as an electrode material in energy storage units for portable and wearable electronic de-vices.Neve...Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is a highly successful conductive polymer utilized as an electrode material in energy storage units for portable and wearable electronic de-vices.Nevertheless,employing PEDOT:PSS in supercapacitors(SC)in its pristine state presents challenges due to its suboptimal electrochemical performance and operational instability.To surmount these limita-tions,PEDOT:PSS has been integrated with carbon-based materials to form flexible electrodes,which ex-hibit physical and chemical stability during SC operation.We developed a streamlined fabrication process for high-performance SC electrodes composed of PEDOT:PSS and carbon quantum dots(CQDs).The CQDs were synthesized under microwave irradiation,yielding green-and red-light emissions.Through optimiz-ing the ratios of CQDs to PEDOT:PSS,the SC electrodes were prepared using a spray-coating technique,marking a significant improvement in device performance with a high volumetric capacitance(104.10 F cm-3),impressive energy density(19.68 Wh cm^(-3)),and excellent cyclic stability,retaining~85% of its original volumetric capacitance after 15,000 repeated GCD cycles.Moreover,the SCs,when utilized as a flexible substrate,demonstrated the ability to maintain up to~85% of their electrochemical performance even after 3,000 bending cycles(at a bending angle of 60°).These attributes render this hybrid composite an ideal candidate for a lightweight smart energy storage component in portable and wearable electronic technologies.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
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
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
Introduction The generation of biological wastes such as cow dung and aloe vera waste(AVW)causes a serious ecological pollution.The microbial electrolytic cell coupled with anaerobic digestion(MEC-AD)system can make a...Introduction The generation of biological wastes such as cow dung and aloe vera waste(AVW)causes a serious ecological pollution.The microbial electrolytic cell coupled with anaerobic digestion(MEC-AD)system can make a rational utilization of these biodegradable organic wastes,which is of vital importance for alleviating environmental deterioration and reducing resource waste.Electrode materials and accelerants are the two major factors that affect methane production in the MEC-AD system.They affect microbial attachment and electron transfer in the MEC-AD system.Bio-based carbon materials are carbon materials prepared from biomass as raw materials.They have characteristics such as a rich pore structure,good chemical stability,biocompatibility,and controllable surface properties,which can be used as accelerants and electrodes in the MEC-AD system to optimize its performance.This study was to investigate the influence of biomass-derived carbon as an electrode and accelerant on the performance of the MEC-AD system,and the mechanism for increasing the production of biogas and methane was also analyzed,thus providing a basis for the multifunctional application of biomass-derived carbon in the MEC-AD system.Methods A series of experimental methods were adopted to study the MEC-AD system.Two types of bio-based carbon,i.e.,aloe vera waste derived spherical carbon(AVW-SC)and porous carbon(AVW-PC),were synthesized via hydrothermal carbonization.The raw AVW material was washed with water,dried,ground,and subjected to hydrothermal treatment to obtain AVW-SC.After activating AVW-SC with KOH,it was carbonized in a tube furnace to obtain AVW-PC.In the preparation of the electrodes,bio-based carbon(AVW-SC and AVW-PC)was mixed with 5%polytetrafluoroethylene powder in ethanol and deionized water,and then ground in a ball mill for 4 h to form a slurry.The slurry was evenly sprayed on the Ti mesh,dried and sintered in N2 atmosphere at 360℃to obtain Ti-SC and Ti-PC electrodes.Four groups of experiments were conducted to determine the optimal voltage,compare different carbon electrodes,and explore the optimal coating amount.The MEC-AD reactor adopted 500 mL wide-mouthed glass bottles with a working volume of 400 mL.Each MEC-AD system received a co-substrate mixture of cattle dung and aloe vera waste and inoculum of sewage sludge in a mass ratio of 3:7.Afterward,they were placed at(36±1)℃for 35 d.The biogas was collected by a water displacement method.The materials were analyzed by characterization techniques such as X-ray diffraction(XRD)and scanning electron microscopy(SEM),and electrochemical tests were conducted on different electrodes.The composition,pH,TS,VS,TCOD and nutrient content of biogas were analyzed by standard chemical methods.Microbial community analysis was conducted using high-throughput sequencing technology.The modified Gompertz model was adopted to predict the kinetic parameters,and the coulombic efficiency and methane recovery rate were calculated according to a specific formula.Results and discussion The result shows that AVW-SC is spherical and closely aggregated,while AVW-PC has a three-dimensional network structure,with average pore diameter of 9.77 nm.The electron exchange capacity(EEC)of AVW-PC(i.e.,0.75μmol·e-/g)is higher than that of AVW-SC(i.e.,0.15μmol·e-/g),indicating a better electron exchange capacity.These results indicate that AVW-PC provides more substrate and bacteria accumulation sites,and has better electron-donating and electron-accepting ability,thus improving the digestion efficiency.In the MEC-AD system,using Ti mesh as an electrode,the effect of different voltages(i.e.,0,0.4,0.6,0.8 V and 1.2 V)on the system performance is investigated,obtaining the optimum biogas production and organic matter degradation rate at 0.8 V.AVW-SC and AVW-PC are respectively coated on Ti mesh as electrodes.The results show that the MEC-AD system with AVW-PC coated Ti mesh as the electrode has a better performance.The electrochemical analysis shows that the electrode coated with AVW-PC has a larger specific capacitance and a smaller charge transfer resistance,indicating that AVW-PC can improve the electrochemical properties and electron transfer ability of MEC-AD system.The influence of coating amount(i.e.,0.025,0.05,0.10,0.15,and 0.20 g)of AVW-PC on the MEC-AD system is investigated.At a coating amount of AVW-PC of 0.1 g,the cumulative biogas production and methane content of the Ti_(0.8)-PC_90.1) group both reach the maximum values.Different doses of AVW-PC(i.e.,0.10%,0.15%,0.20%,and 0.25%)are added as accelerants in Ti_(0.8)-PC_90.1).At the addition amount of AVW-PC of 0.20%,the Ti_(0.8)-PC_90.1)/PC0.2 group performs the optimum biogas production(i.e.,633.63 mL/g VS),methane content(i.e.,65.85%),and total nutrient content of biogas residue(i.e.,42.30 g/kg).In Ti_(0.8)-PC_90.1)/PC0.2,Bacteroidales,Pseudomonadales,Oscillospirales,Methanobacteraceae,Methanospirillaceae,Methanosarcinacea and Methanosaetaceae significantly increase.The increase in microbial diversity promotes interspecific hydrogen transfer(IHT),interspecific acetic transfer(IAT),and direct interspecific electron transfer(DIET),thereby enhancing methanogenic efficiency.Conclusions AVW-SC and AVW-PC were utilized as electrodes and accelerants to enhance methane yield in MEC-AD system.The Ti mesh electrode coated with different concentrations of AVW-PC achieved the optimal biogas production at 0.8 V.Specifically,the Ti_(0.8)-PC_90.1) combination could generate the maximum total amount of biogas and methane proportion.The Ti_(0.8)-PC_90.1)/PC0.2 combination exhibited the optimum performance(i.e.,biogas yield of 633.63 mL/g VS,methane content of 65.85%and total nutritional content of 42.30 g/kg).High abundances of Bacteroidales,Pseudomonadales,Oscillospirales,Methanobacteraceae,Methanospirillaceae,Methanosarcinaceae,and Methanosaetaceae appeared in the Ti_(0.8)-PC_90.1)/PC0.2 group,compared to other groups.In addition,an increased microbial diversity led to an enhanced methane production through processes like DIET.This research could highlight the potential significance of AVW-PC as both electrode and accelerator for increasing methane production and provide a perspective for improving MEC-AD performance through multiple applications of biomass-derived carbon.展开更多
Surgical electrodes are frequently associated with disadvantages such as high surface adhesion and severe thermal damage to adjacent normal tissues,which threaten operation quality and patient safety.In this study,by ...Surgical electrodes are frequently associated with disadvantages such as high surface adhesion and severe thermal damage to adjacent normal tissues,which threaten operation quality and patient safety.In this study,by mimicking the micromorphology and bio-anti-adhesion of shark skin,we proposed a strategy that utilized nanoscale aluminium oxide(Al_(2)O_(3))films deposited on bioinspired shark skin(BSS)microstructures to design a composite surface(Al_(2)O_(3)@BSS)and integrated it into both flat sides of the surgical electrodes.Micro/nano-manufacturing of the Al_(2)O_(3)@BSS surface was sequentially accomplished using nanosecond laser texturing,atomic layer deposition,and low-temperature annealing,endowing it with excellent blood-repellent properties.Visualisation experiments revealed that the tensile stress gradient of the blood coagulum with increasing thickness under a thermal field prompted it to separate from the Al_(2)O_(3)@BSS surface,resulting in anti-adhesion.Furthermore,it was observed for the first time that Al_(2)O_(3) films could transiently excite discharge along a dielectric surface(DADS)to ablate tissues while suppressing Joule heat,thereby minimising thermal damage.A combination of ex vivo tissue and living mouse experiments demonstrated that the Al_(2)O_(3)@BSS electrodes exhibited optimal comprehensive performance in terms of anti-adhesion,damage minimisation,and drag reduction.In addition,the Al_(2)O_(3)@BSS electrodes possessed remarkable antibacterial efficacy against E.coli and S.aureus.The proposed strategy can meet the extreme application requirements of surgical electrodes to improve operation quality and offer valuable insights for future studies.展开更多
In order to address the current inability of screen printing to monitor printing pressure online,an online printing pressure monitoring system applied to screen printing machines was designed in this study.In this stu...In order to address the current inability of screen printing to monitor printing pressure online,an online printing pressure monitoring system applied to screen printing machines was designed in this study.In this study,the consistency of printed electrodes was measured by using a confocal microscope and the pressure distribution detected by online pressure monitoring system was compared to investigate the relationship.The results demonstrated the relationship between printing pressure and the consistency of printed electrodes.As printing pressure increases,the ink layer at the corresponding position becomes thicker and that higher printing pressure enhances the consistency of the printed electrodes.The experiment confirms the feasibility of the online pressure monitoring system,which aids in predicting and controlling the consistency of printed electrodes,thereby improving their performance.展开更多
As a negative electrode material for lithium-ion batteries,silicon monoxide(SiO)suffers from dramatic volume changes during cycling,causing excessive stress within the electrode and resulting in electrode deformation ...As a negative electrode material for lithium-ion batteries,silicon monoxide(SiO)suffers from dramatic volume changes during cycling,causing excessive stress within the electrode and resulting in electrode deformation and fragmentation.This ultimately leads to a decrease in cell capacity.The trends of volume expansion and capacity change of the SiO/graphite(SiO/C)composite electrode during cycling were investigated via in situ expansion monitoring.First,a series of expansion test schemes were designed,and the linear relationship between negative electrode expansion and cell capacity degradation was quantitatively analyzed.Then,the effects of different initial pressures on the long-term cycling performance of the cell were evaluated.Finally,the mechanism of their effects was analyzed by scanning electron microscope.The results show that after 50 cycles,the cell capacity decreases from 2.556 mAh to 1.689 mAh,with a capacity retention ratio(CRR)of only 66.08%.A linear relationship between the capacity retention ratio and thickness expansion was found.Electrochemical measurements and scanning electron microscope images demonstrate that intense stress inhibits the lithiation of the negative electrode and that the electrode is more susceptible to irreversible damage during cycling.Overall,these results reveal the relationship between the cycling performance of SiO and the internal pressure of the electrode from a macroscopic point of view,which provides some reference for the application of SiO/C composite electrodes in lithium-ion batteries.展开更多
The oil-based mud(OBM) borehole measurement environment presents significant limitations on the application of existing electrical logging instruments in high-resistance formations. In this paper, we propose a novel l...The oil-based mud(OBM) borehole measurement environment presents significant limitations on the application of existing electrical logging instruments in high-resistance formations. In this paper, we propose a novel logging method for detection of high-resistance formations in OBM using highfrequency electrodes. The method addresses the issue of shallow depth of investigation(DOI) in existing electrical logging instruments, while simultaneously ensuring the vertical resolution. Based on the principle of current continuity, the total impedance of the loop is obtained by equating the measurement loop to the series form of a capacitively coupled circuit. and its validity is verified in a homogeneous formation model and a radial two-layer formation model with a mud standoff. Then, the instrument operating frequency and electrode system parameters were preferentially determined by numerical simulation, and the effect of mud gap on impedance measurement was investigated. Subsequently, the DOI of the instrument was investigated utilizing the pseudo-geometric factor defined by the real part of impedance. It was determined that the detection depth of the instrument is 8.74 cm, while the effective vertical resolution was not less than 2 cm. Finally, a focused high-frequency electrode-type instrument was designed by introducing a pair of focused electrodes, which effectively enhanced the DOI of the instrument and was successfully deployed in the Oklahoma formation model. The simulation results demonstrate that the novel method can achieve a detection depth of 17.40 cm in highly-resistive formations drilling with OBM, which is approximately twice the depth of detection of the existing oil-based mud microimager instruments. Furthermore, its effective vertical resolution remains at or above 2 cm,which is comparable to the resolution of the existing OBM electrical logging instrument.展开更多
The three-dimensional particle electrode system exhibits significant potential for application in the treatment of wastewater.Nonetheless,the advancement of effective granular electrodes characterized by elevated cata...The three-dimensional particle electrode system exhibits significant potential for application in the treatment of wastewater.Nonetheless,the advancement of effective granular electrodes characterized by elevated catalytic activity and minimal energy consumption continues to pose a significant challenge.In this research,Fluorine-doped copper-carbon(F/Cu-GAC)particle electrodes were effectively synthesized through an impregnationcalcination technique,utilizing granular activated carbon as the carrier and fluorinedoped modified copper oxides as the catalytic agents.The particle electrodes were subsequently utilized to promote the degradation of 2,4,6-trichlorophenol(2,4,6-TCP)in a threedimensional electrocatalytic reactor(3DER).The F/Cu-GAC particle electrodes were polarized under the action of electric field,which promoted the heterogeneous Fenton-like reaction in which H2O2 generated by two-electron oxygen reduction reaction(2e-ORR)of O_(2) was catalytically decomposed to·OH.The 3DER equipped with F/Cu-GAC particle electrodes showed 100%removal of 2,4,6-TCP and 79.24%removal of TOC with a specific energy consumption(EC)of approximately 0.019 kWh/g·COD after 2 h of operation.The F/Cu-GAC particle electrodes exhibited an overpotential of 0.38 V and an electrochemically active surface area(ECSA)of 715 cm^(2),as determined through linear sweep voltammetry(LSV)and cyclic voltammetry(CV)assessments.These findings suggest a high level of electrocatalytic performance.Furthermore,the catalytic mechanism of the 3DER equipped with F/Cu-GAC particle electrodes was elucidated through the application of X-ray photoelectron spectroscopy(XPS),electron spin resonance(ESR),and active species capture experiments.This investigation offers a novel approach for the effective degradation of 2,4,6-TCP.展开更多
Developing efficient and stable electrocatalysts has always been the focus of electrochemical research.Here,sea urchin-like nickel-molybdenum bimetallic phosphide nickel-molybdenum alloy(Ni_(4)Mo)and(Ni-Mo-P)were succ...Developing efficient and stable electrocatalysts has always been the focus of electrochemical research.Here,sea urchin-like nickel-molybdenum bimetallic phosphide nickel-molybdenum alloy(Ni_(4)Mo)and(Ni-Mo-P)were successfully synthesized by hydrothermal,annealing and phosphating methods on nickel foam(NF).The unusual shape of the sea urchin facilitates gas release and mass transfer and increases the interaction between catalysts and electrolytes.The Ni_(4)Mo/NF and Ni-Mo-P/NF electrodes only need overpotentials of 72 and 197 mV to reach 50 mA·cm^(−2) under alkaline conditions for hydrogen evolution reaction and oxygen evolution reaction,respectively.The Ni_(4)Mo/NF and Ni-Mo-P/NF asymmetric electrodes were used as anode and cathode for the overall water splitting,respectively.In 1.0 M KOH,at a voltage of 1.485 V,the electrolytic device generated 50 mA·cm^(−2) current density,maintaining for 24 h without reduction.The labor presents a simple method to synthesize a highly active,low-cost,and strongly durable self-supporting electrode for over-water splitting.展开更多
Supercapacitors are efficient and versatile energy storage devices,offering remarkable power density,fast charge/discharge rates,and exceptional cycle life.As research continues to push the boundaries of their perform...Supercapacitors are efficient and versatile energy storage devices,offering remarkable power density,fast charge/discharge rates,and exceptional cycle life.As research continues to push the boundaries of their performance,electrode fabrication techniques are critical aspects influencing the overall capabilities of supercapacitors.Herein,we aim to shed light on the advantages offered by dry electrode processing for advanced supercapacitors.Notably,our study explores the performance of these electrodes in three different types of electrolytes:organic,ionic liquids,and quasi-solid states.By examining the impact of dry electrode processing on various electrode and electrolyte systems,we show valuable insights into the versatility and efficacy of this technique.The supercapacitors employing dry electrodes demonstrated significant improvements compared with conventional wet electrodes,with a lifespan extension of+45%in organic,+192%in ionic liquids,and+84%in quasi-solid electrolytes.Moreover,the increased electrode densities achievable through the dry approach directly translate to improved volumetric outputs,enhancing energy storage capacities within compact form factors.Notably,dry electrode-prepared supercapacitors outperformed their wet electrode counterparts,exhibiting a higher energy density of 6.1 Wh cm^(-3)compared with 4.7 Wh cm^(-3)at a high power density of 195Wcm^(-3),marking a substantial 28%energy improvement in the quasi-solid electrolyte.展开更多
The silicon-graphite(Si-C)composite electrode is considered a promising candidate for next-generation commercial electrodes due to its high capacity.However,lithium-ion batteries with silicon electrodes often experien...The silicon-graphite(Si-C)composite electrode is considered a promising candidate for next-generation commercial electrodes due to its high capacity.However,lithium-ion batteries with silicon electrodes often experience capacity fading and poor cyclic performance,primarily due to the mechanical degradation of the solid-electrolyte interphase(SEI).In this work,we present a homogenized constitutive model for Si-C composite electrodes under finite deformation,incorporating lithium-ion concentration-dependent properties.We perform a wrinkling analysis and systematically examine the influence of key parameters,such as modulus and thickness ratios,on the critical conditions for instability.Additionally,we investigate the ratcheting effect across varying silicon contents.Our findings reveal that maintaining the silicon content within an optimal range effectively reduces plastic accumulation during charge–discharge cycles.These insights provide crucial guidance for optimizing the design and fabrication of Si–C electrode systems,enhancing their durability and performance.展开更多
In pursuit of meeting the demands for the next generation of high energy density and flexible electronic products,there is a growing interest in flexible energy storage devices.Silicon(Si)stands out as a promising ele...In pursuit of meeting the demands for the next generation of high energy density and flexible electronic products,there is a growing interest in flexible energy storage devices.Silicon(Si)stands out as a promising electrode material due to its high theoretical specific capacity(~3579 mA h g^(-1)),low lithiation potential(~0.40 V),and abundance in nature.We have successfully developed freestanding and flexible CNT/Si/low-melting-point metal(LM)electrodes,which obviate the need for conductive additives,adhesives,and thereby increase the energy density of the device.As an anode material for lithium-ion batteries(LIBs),the CNT/Si/LM electrode demonstrates remarkable cycling stability and rate performance,achieving a reversible capacity of 1871.8 mA h g^(-1)after 100 cycles at a current density of 0.2 A g^(-1).In-situ XRD and in-situ thickness analysis are employed to elucidate the underlying mechanisms during the lithiation/delithiation.Density functional theory(DFT)calculations further substantiate the mechanism by which LM enhances the electrochemical performance of Si,focusing on the aspects of stress mitigation and reduction of the diffusion energy barrier.This research introduces a novel approach to flexible electrode design by integrating CNT films,LM,and Si,thereby charting a path forward for the development of next-generation flexible LIBs.展开更多
Rapid developments in lithium-ion battery(LIB)technology have been fueled by the expanding market for electric vehicles and increased demands for energy storage.Recently,thick electrode fabrication by solvent-free met...Rapid developments in lithium-ion battery(LIB)technology have been fueled by the expanding market for electric vehicles and increased demands for energy storage.Recently,thick electrode fabrication by solvent-free methods has emerged as a promising strategy for enhancing the energy density of LIBs.However,as electrode thickness increases,the tortuosity of lithium-ion transport also increases,resulting in severe polarization and poor electrochemical performance.Here,we investigate the effect of conductive agent morphology on the structural and electrochemical properties of 250μm thick lithium iron phosphate(LFP)/conductive agent/polytetrafluoroethylene(PTFE)-based electrodes.Three commercially available conductive additives,namely 0D Super P,1D multi-walled carbon nanotubes(MWCNTs),and 2D graphene nanoplatelets(GNPs),were incorporated into LFP-based electrodes.The MWCNT-incorporated electrode with a high loading mass(42 mg cm^(-2))exhibited a high porosity(ε=51%)and low tortuosity(τ=4.02)owing to its highly interconnected fibrous network of MWCNTs.Due to the fast lithium-ion transport kinetics in the MWCNT-incorporated electrode,the electrochemical performances exhibited a high specific capacity of 157 mAh g^(-1)at 0.1 C and an areal capacity of 7.16 mAh cm^(-2)at 0.1 C with a high-rate capability and excellent cycling stability over 300 cycles at 0.1 C.This study provides a guidance for utilizing conductive agents to apply in the low tortuous thick electrode fabricated by a solvent-free process.Additionally,this work paves the way to achieve scalable and sustainable dry processing techniques for developing next-generation energy storage technologies.展开更多
基金supported by the University of Seoul’s 2025 Research Fund.
文摘Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.
基金supported by the Basic and Applied Basic Research Foundation of Guangdong province(2024A1515030155 and 2022A1515010272)Natural Science Foundation of China(61904067)+2 种基金Basic and Applied Basic Research Foundation of Guangzhou city(202102020758)Open funding from State Key Laboratory of Optoelectronic Materials and Technologies(Sun Yat-Sen University,OEMT2022-KF-08)Fundamental Research Funds for the Central Universities(11625109,11621405)。
文摘Metals,indispensable since the Bronze Age,remain pivotal in modern technologies due to their exceptional properties and versatility.Beyond traditional machining,advanced nano/micro-machining techniques enable the fabrication of metallic nano/micro structures with high precision in shape,size,and pattern.These structures endow flexible electrodes with outstanding electrical,mechanical,optical,and electrochemical performance,enabling growing applications in flexible optoelectronics,epidermal electronics,energy harvesting,and biochemical sensing.This review provides a comprehensive overview of the fabrication strategies for flexible electrodes made from metal meshes,metal nanowires,and liquid metals.The current advancements,existing challenges,and emerging technologies are systematically discussed.Furthermore,the progression toward ultra-thin,soft epidermal electrodes is explored,with an emphasis on novel in situ and transfer fabrication methods.We examine the underlying mechanisms,performance indicators,and their integration for on-skin applications,including bioelectric sensing,electrical stimulation,and energy harvesting.Finally,we highlight the remaining challenges in performance improvement and industrialization of flexible and epidermal electrodes,along with future opportunities for integrating multimodal systems and leveraging artificial intelligence to enhance their functionalities.
基金Project supported by the National Natural Science Foundation of China(Nos.12502117,12272269,11972257)the Natural Science Foundation of Ningxia of China(No.2024AAC03018)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Shanghai Gaofeng Project for University Academic Program Development。
文摘Driven by the trend of device miniaturization and high-density integration,the interaction between adjacent electrodes has become a critical factor affecting the interfacial reliability of thermoelectric(TE)structures.This study investigates the influence of adjoining electrode interactions on the interfacial response of a multi-electrode/TE substrate structure,including interfacial stresses and stress intensity factors at the electrode ends.To solve the corresponding boundary-value problem,the Fourier transforms are adopted to derive a governing integro-differential equation for the interfacial shear stress in multi-electrode systems,incorporating the TE effects as generalized forces on the right-hand side.The results show that both the interfacial tension and transverse stress in the electrodes are significantly affected by the presence of adjacent electrodes.The interaction between neighboring electrodes diminishes as their spacing increases or when an adhesive interlayer is introduced.Furthermore,the softer and thinner electrodes,the softer and thicker adhesive interlayer,and the smaller TE loads are found to be beneficial for improving the interfacial performance.These findings may contribute to the accurate measurement in surface sensors and layout design of multi-point health monitoring systems for TE structures.
基金part of the ALU-STORE project(Aluminum Metal as Energy Carrier for Seasonal Energy Storage)funded by the KIT Future Fieldsthe research performed at CELEST(Center for Electrochemical Energy Storage Ulm-Karlsruhe)+1 种基金funding from the German Federal Ministry of Research,Technology and Space(BMFTR)in the Nano Mat Futur program(03XP0423)basic funding from the Helmholtz Association。
文摘α-MnO_(2) is a promising,inexpensive,and readily producible catalyst for the oxygen reduction reaction(ORR)in alkaline media,but its application is limited by low electronic conductivity.In this study,we enhance the performance ofα-MnO_(2) electrodes by systematically varying theα-MnO_(2)-to-Vulcan ratio within the catalyst layer.Electrodes are evaluated in a gas diffusion electrode(GDE)half-cell,where an optimized catalyst layer composition leads to significantly improved ORR performance.By finetuning both theα-MnO_(2)-to-Vulcan ratio and theα-MnO_(2) loading,the electrode outperforms a commercial MnO_(2)-based electrode and approaches the performance of the Pt/C benchmark.The improvement is attributed to the presence of a three-dimensional(3D)Vulcan network electronically connecting catalytically activeα-MnO_(2) sites with the substrate.Additionally,the optimized electrodes are employed in a prototype Al-O_(2) flow cell.Under constant oxygen flow,power densities exceed 250 mW cm^(-2),which is significantly higher than that of conventional Al-air batteries.Electrochemical impedance spectroscopy combined with distribution of relaxation times(DRT)analysis enables the separation of anode and cathode charge transfer impedances without the need for an additional reference electrode.The analysis reveals that the anode contributes more than twice as much impedance as the cathode,highlighting the need for further anode optimization.This work demonstrates a transferable approach for catalyst layer screening under technically relevant conditions in the GDE half-cell.Subsequent measurements in an Al-O_(2) flow cell validate the approach.The methodology is widely applicable to the development of advanced electrodes for a variety of metal-air battery technologies.
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supported by the National Research Foundation of Korea(NRF)through a grant provided by the Korean government(No.NRF-2021R1F1A1063451).
文摘Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is a highly successful conductive polymer utilized as an electrode material in energy storage units for portable and wearable electronic de-vices.Nevertheless,employing PEDOT:PSS in supercapacitors(SC)in its pristine state presents challenges due to its suboptimal electrochemical performance and operational instability.To surmount these limita-tions,PEDOT:PSS has been integrated with carbon-based materials to form flexible electrodes,which ex-hibit physical and chemical stability during SC operation.We developed a streamlined fabrication process for high-performance SC electrodes composed of PEDOT:PSS and carbon quantum dots(CQDs).The CQDs were synthesized under microwave irradiation,yielding green-and red-light emissions.Through optimiz-ing the ratios of CQDs to PEDOT:PSS,the SC electrodes were prepared using a spray-coating technique,marking a significant improvement in device performance with a high volumetric capacitance(104.10 F cm-3),impressive energy density(19.68 Wh cm^(-3)),and excellent cyclic stability,retaining~85% of its original volumetric capacitance after 15,000 repeated GCD cycles.Moreover,the SCs,when utilized as a flexible substrate,demonstrated the ability to maintain up to~85% of their electrochemical performance even after 3,000 bending cycles(at a bending angle of 60°).These attributes render this hybrid composite an ideal candidate for a lightweight smart energy storage component in portable and wearable electronic technologies.
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.
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.
文摘Introduction The generation of biological wastes such as cow dung and aloe vera waste(AVW)causes a serious ecological pollution.The microbial electrolytic cell coupled with anaerobic digestion(MEC-AD)system can make a rational utilization of these biodegradable organic wastes,which is of vital importance for alleviating environmental deterioration and reducing resource waste.Electrode materials and accelerants are the two major factors that affect methane production in the MEC-AD system.They affect microbial attachment and electron transfer in the MEC-AD system.Bio-based carbon materials are carbon materials prepared from biomass as raw materials.They have characteristics such as a rich pore structure,good chemical stability,biocompatibility,and controllable surface properties,which can be used as accelerants and electrodes in the MEC-AD system to optimize its performance.This study was to investigate the influence of biomass-derived carbon as an electrode and accelerant on the performance of the MEC-AD system,and the mechanism for increasing the production of biogas and methane was also analyzed,thus providing a basis for the multifunctional application of biomass-derived carbon in the MEC-AD system.Methods A series of experimental methods were adopted to study the MEC-AD system.Two types of bio-based carbon,i.e.,aloe vera waste derived spherical carbon(AVW-SC)and porous carbon(AVW-PC),were synthesized via hydrothermal carbonization.The raw AVW material was washed with water,dried,ground,and subjected to hydrothermal treatment to obtain AVW-SC.After activating AVW-SC with KOH,it was carbonized in a tube furnace to obtain AVW-PC.In the preparation of the electrodes,bio-based carbon(AVW-SC and AVW-PC)was mixed with 5%polytetrafluoroethylene powder in ethanol and deionized water,and then ground in a ball mill for 4 h to form a slurry.The slurry was evenly sprayed on the Ti mesh,dried and sintered in N2 atmosphere at 360℃to obtain Ti-SC and Ti-PC electrodes.Four groups of experiments were conducted to determine the optimal voltage,compare different carbon electrodes,and explore the optimal coating amount.The MEC-AD reactor adopted 500 mL wide-mouthed glass bottles with a working volume of 400 mL.Each MEC-AD system received a co-substrate mixture of cattle dung and aloe vera waste and inoculum of sewage sludge in a mass ratio of 3:7.Afterward,they were placed at(36±1)℃for 35 d.The biogas was collected by a water displacement method.The materials were analyzed by characterization techniques such as X-ray diffraction(XRD)and scanning electron microscopy(SEM),and electrochemical tests were conducted on different electrodes.The composition,pH,TS,VS,TCOD and nutrient content of biogas were analyzed by standard chemical methods.Microbial community analysis was conducted using high-throughput sequencing technology.The modified Gompertz model was adopted to predict the kinetic parameters,and the coulombic efficiency and methane recovery rate were calculated according to a specific formula.Results and discussion The result shows that AVW-SC is spherical and closely aggregated,while AVW-PC has a three-dimensional network structure,with average pore diameter of 9.77 nm.The electron exchange capacity(EEC)of AVW-PC(i.e.,0.75μmol·e-/g)is higher than that of AVW-SC(i.e.,0.15μmol·e-/g),indicating a better electron exchange capacity.These results indicate that AVW-PC provides more substrate and bacteria accumulation sites,and has better electron-donating and electron-accepting ability,thus improving the digestion efficiency.In the MEC-AD system,using Ti mesh as an electrode,the effect of different voltages(i.e.,0,0.4,0.6,0.8 V and 1.2 V)on the system performance is investigated,obtaining the optimum biogas production and organic matter degradation rate at 0.8 V.AVW-SC and AVW-PC are respectively coated on Ti mesh as electrodes.The results show that the MEC-AD system with AVW-PC coated Ti mesh as the electrode has a better performance.The electrochemical analysis shows that the electrode coated with AVW-PC has a larger specific capacitance and a smaller charge transfer resistance,indicating that AVW-PC can improve the electrochemical properties and electron transfer ability of MEC-AD system.The influence of coating amount(i.e.,0.025,0.05,0.10,0.15,and 0.20 g)of AVW-PC on the MEC-AD system is investigated.At a coating amount of AVW-PC of 0.1 g,the cumulative biogas production and methane content of the Ti_(0.8)-PC_90.1) group both reach the maximum values.Different doses of AVW-PC(i.e.,0.10%,0.15%,0.20%,and 0.25%)are added as accelerants in Ti_(0.8)-PC_90.1).At the addition amount of AVW-PC of 0.20%,the Ti_(0.8)-PC_90.1)/PC0.2 group performs the optimum biogas production(i.e.,633.63 mL/g VS),methane content(i.e.,65.85%),and total nutrient content of biogas residue(i.e.,42.30 g/kg).In Ti_(0.8)-PC_90.1)/PC0.2,Bacteroidales,Pseudomonadales,Oscillospirales,Methanobacteraceae,Methanospirillaceae,Methanosarcinacea and Methanosaetaceae significantly increase.The increase in microbial diversity promotes interspecific hydrogen transfer(IHT),interspecific acetic transfer(IAT),and direct interspecific electron transfer(DIET),thereby enhancing methanogenic efficiency.Conclusions AVW-SC and AVW-PC were utilized as electrodes and accelerants to enhance methane yield in MEC-AD system.The Ti mesh electrode coated with different concentrations of AVW-PC achieved the optimal biogas production at 0.8 V.Specifically,the Ti_(0.8)-PC_90.1) combination could generate the maximum total amount of biogas and methane proportion.The Ti_(0.8)-PC_90.1)/PC0.2 combination exhibited the optimum performance(i.e.,biogas yield of 633.63 mL/g VS,methane content of 65.85%and total nutritional content of 42.30 g/kg).High abundances of Bacteroidales,Pseudomonadales,Oscillospirales,Methanobacteraceae,Methanospirillaceae,Methanosarcinaceae,and Methanosaetaceae appeared in the Ti_(0.8)-PC_90.1)/PC0.2 group,compared to other groups.In addition,an increased microbial diversity led to an enhanced methane production through processes like DIET.This research could highlight the potential significance of AVW-PC as both electrode and accelerator for increasing methane production and provide a perspective for improving MEC-AD performance through multiple applications of biomass-derived carbon.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52275425,52405473,and 52405472)the Natural Science Foundation of Guangdong Province(Grant No.2024A1515010993)。
文摘Surgical electrodes are frequently associated with disadvantages such as high surface adhesion and severe thermal damage to adjacent normal tissues,which threaten operation quality and patient safety.In this study,by mimicking the micromorphology and bio-anti-adhesion of shark skin,we proposed a strategy that utilized nanoscale aluminium oxide(Al_(2)O_(3))films deposited on bioinspired shark skin(BSS)microstructures to design a composite surface(Al_(2)O_(3)@BSS)and integrated it into both flat sides of the surgical electrodes.Micro/nano-manufacturing of the Al_(2)O_(3)@BSS surface was sequentially accomplished using nanosecond laser texturing,atomic layer deposition,and low-temperature annealing,endowing it with excellent blood-repellent properties.Visualisation experiments revealed that the tensile stress gradient of the blood coagulum with increasing thickness under a thermal field prompted it to separate from the Al_(2)O_(3)@BSS surface,resulting in anti-adhesion.Furthermore,it was observed for the first time that Al_(2)O_(3) films could transiently excite discharge along a dielectric surface(DADS)to ablate tissues while suppressing Joule heat,thereby minimising thermal damage.A combination of ex vivo tissue and living mouse experiments demonstrated that the Al_(2)O_(3)@BSS electrodes exhibited optimal comprehensive performance in terms of anti-adhesion,damage minimisation,and drag reduction.In addition,the Al_(2)O_(3)@BSS electrodes possessed remarkable antibacterial efficacy against E.coli and S.aureus.The proposed strategy can meet the extreme application requirements of surgical electrodes to improve operation quality and offer valuable insights for future studies.
文摘In order to address the current inability of screen printing to monitor printing pressure online,an online printing pressure monitoring system applied to screen printing machines was designed in this study.In this study,the consistency of printed electrodes was measured by using a confocal microscope and the pressure distribution detected by online pressure monitoring system was compared to investigate the relationship.The results demonstrated the relationship between printing pressure and the consistency of printed electrodes.As printing pressure increases,the ink layer at the corresponding position becomes thicker and that higher printing pressure enhances the consistency of the printed electrodes.The experiment confirms the feasibility of the online pressure monitoring system,which aids in predicting and controlling the consistency of printed electrodes,thereby improving their performance.
基金supported by the Fundamental Research Funds for the Central Universities(WK2090000055)Anhui Provincial Natural Science Foundation of China(2308085QG231).
文摘As a negative electrode material for lithium-ion batteries,silicon monoxide(SiO)suffers from dramatic volume changes during cycling,causing excessive stress within the electrode and resulting in electrode deformation and fragmentation.This ultimately leads to a decrease in cell capacity.The trends of volume expansion and capacity change of the SiO/graphite(SiO/C)composite electrode during cycling were investigated via in situ expansion monitoring.First,a series of expansion test schemes were designed,and the linear relationship between negative electrode expansion and cell capacity degradation was quantitatively analyzed.Then,the effects of different initial pressures on the long-term cycling performance of the cell were evaluated.Finally,the mechanism of their effects was analyzed by scanning electron microscope.The results show that after 50 cycles,the cell capacity decreases from 2.556 mAh to 1.689 mAh,with a capacity retention ratio(CRR)of only 66.08%.A linear relationship between the capacity retention ratio and thickness expansion was found.Electrochemical measurements and scanning electron microscope images demonstrate that intense stress inhibits the lithiation of the negative electrode and that the electrode is more susceptible to irreversible damage during cycling.Overall,these results reveal the relationship between the cycling performance of SiO and the internal pressure of the electrode from a macroscopic point of view,which provides some reference for the application of SiO/C composite electrodes in lithium-ion batteries.
基金the National Natural Science Foundation of China(42074134,42474152,42374150)CNPC Innovation Found(2024DQ02-0152).
文摘The oil-based mud(OBM) borehole measurement environment presents significant limitations on the application of existing electrical logging instruments in high-resistance formations. In this paper, we propose a novel logging method for detection of high-resistance formations in OBM using highfrequency electrodes. The method addresses the issue of shallow depth of investigation(DOI) in existing electrical logging instruments, while simultaneously ensuring the vertical resolution. Based on the principle of current continuity, the total impedance of the loop is obtained by equating the measurement loop to the series form of a capacitively coupled circuit. and its validity is verified in a homogeneous formation model and a radial two-layer formation model with a mud standoff. Then, the instrument operating frequency and electrode system parameters were preferentially determined by numerical simulation, and the effect of mud gap on impedance measurement was investigated. Subsequently, the DOI of the instrument was investigated utilizing the pseudo-geometric factor defined by the real part of impedance. It was determined that the detection depth of the instrument is 8.74 cm, while the effective vertical resolution was not less than 2 cm. Finally, a focused high-frequency electrode-type instrument was designed by introducing a pair of focused electrodes, which effectively enhanced the DOI of the instrument and was successfully deployed in the Oklahoma formation model. The simulation results demonstrate that the novel method can achieve a detection depth of 17.40 cm in highly-resistive formations drilling with OBM, which is approximately twice the depth of detection of the existing oil-based mud microimager instruments. Furthermore, its effective vertical resolution remains at or above 2 cm,which is comparable to the resolution of the existing OBM electrical logging instrument.
基金supported by Guangxi Science and Technology Major Program(No.AA23073008)Hubei Key Laboratory of Water System Science for Sponge City Construction(Wuhan University)(No.2023–05)Nanning Innovation and Entrepreneur Leading Talent Project(No.2021001).
文摘The three-dimensional particle electrode system exhibits significant potential for application in the treatment of wastewater.Nonetheless,the advancement of effective granular electrodes characterized by elevated catalytic activity and minimal energy consumption continues to pose a significant challenge.In this research,Fluorine-doped copper-carbon(F/Cu-GAC)particle electrodes were effectively synthesized through an impregnationcalcination technique,utilizing granular activated carbon as the carrier and fluorinedoped modified copper oxides as the catalytic agents.The particle electrodes were subsequently utilized to promote the degradation of 2,4,6-trichlorophenol(2,4,6-TCP)in a threedimensional electrocatalytic reactor(3DER).The F/Cu-GAC particle electrodes were polarized under the action of electric field,which promoted the heterogeneous Fenton-like reaction in which H2O2 generated by two-electron oxygen reduction reaction(2e-ORR)of O_(2) was catalytically decomposed to·OH.The 3DER equipped with F/Cu-GAC particle electrodes showed 100%removal of 2,4,6-TCP and 79.24%removal of TOC with a specific energy consumption(EC)of approximately 0.019 kWh/g·COD after 2 h of operation.The F/Cu-GAC particle electrodes exhibited an overpotential of 0.38 V and an electrochemically active surface area(ECSA)of 715 cm^(2),as determined through linear sweep voltammetry(LSV)and cyclic voltammetry(CV)assessments.These findings suggest a high level of electrocatalytic performance.Furthermore,the catalytic mechanism of the 3DER equipped with F/Cu-GAC particle electrodes was elucidated through the application of X-ray photoelectron spectroscopy(XPS),electron spin resonance(ESR),and active species capture experiments.This investigation offers a novel approach for the effective degradation of 2,4,6-TCP.
基金supported by the Natural Science Research Project of Jiangsu Higher Education Institutions(No.23KJD150005)the Scientific Research Project of Nanjing Xiaozhuang University(No.2022NXY29).
文摘Developing efficient and stable electrocatalysts has always been the focus of electrochemical research.Here,sea urchin-like nickel-molybdenum bimetallic phosphide nickel-molybdenum alloy(Ni_(4)Mo)and(Ni-Mo-P)were successfully synthesized by hydrothermal,annealing and phosphating methods on nickel foam(NF).The unusual shape of the sea urchin facilitates gas release and mass transfer and increases the interaction between catalysts and electrolytes.The Ni_(4)Mo/NF and Ni-Mo-P/NF electrodes only need overpotentials of 72 and 197 mV to reach 50 mA·cm^(−2) under alkaline conditions for hydrogen evolution reaction and oxygen evolution reaction,respectively.The Ni_(4)Mo/NF and Ni-Mo-P/NF asymmetric electrodes were used as anode and cathode for the overall water splitting,respectively.In 1.0 M KOH,at a voltage of 1.485 V,the electrolytic device generated 50 mA·cm^(−2) current density,maintaining for 24 h without reduction.The labor presents a simple method to synthesize a highly active,low-cost,and strongly durable self-supporting electrode for over-water splitting.
基金funding of the joint Polish-German project SUPILMIX(PR-1173/27)by the German Research Foundation(DFG,Deutsche Forschungsgemeinschaft)+1 种基金funding from the Alexander von Humboldt Foundation.D.L.the German Chemical Industry Fund for the financial support through a Liebig Fellowship.
文摘Supercapacitors are efficient and versatile energy storage devices,offering remarkable power density,fast charge/discharge rates,and exceptional cycle life.As research continues to push the boundaries of their performance,electrode fabrication techniques are critical aspects influencing the overall capabilities of supercapacitors.Herein,we aim to shed light on the advantages offered by dry electrode processing for advanced supercapacitors.Notably,our study explores the performance of these electrodes in three different types of electrolytes:organic,ionic liquids,and quasi-solid states.By examining the impact of dry electrode processing on various electrode and electrolyte systems,we show valuable insights into the versatility and efficacy of this technique.The supercapacitors employing dry electrodes demonstrated significant improvements compared with conventional wet electrodes,with a lifespan extension of+45%in organic,+192%in ionic liquids,and+84%in quasi-solid electrolytes.Moreover,the increased electrode densities achievable through the dry approach directly translate to improved volumetric outputs,enhancing energy storage capacities within compact form factors.Notably,dry electrode-prepared supercapacitors outperformed their wet electrode counterparts,exhibiting a higher energy density of 6.1 Wh cm^(-3)compared with 4.7 Wh cm^(-3)at a high power density of 195Wcm^(-3),marking a substantial 28%energy improvement in the quasi-solid electrolyte.
基金supported by the National Natural Science Foundation of China(Grants Nos.12172102 and 12372097)the Fundamental Research Funds for the Central Universities(Grant No.HIT.OCEF.2022013).
文摘The silicon-graphite(Si-C)composite electrode is considered a promising candidate for next-generation commercial electrodes due to its high capacity.However,lithium-ion batteries with silicon electrodes often experience capacity fading and poor cyclic performance,primarily due to the mechanical degradation of the solid-electrolyte interphase(SEI).In this work,we present a homogenized constitutive model for Si-C composite electrodes under finite deformation,incorporating lithium-ion concentration-dependent properties.We perform a wrinkling analysis and systematically examine the influence of key parameters,such as modulus and thickness ratios,on the critical conditions for instability.Additionally,we investigate the ratcheting effect across varying silicon contents.Our findings reveal that maintaining the silicon content within an optimal range effectively reduces plastic accumulation during charge–discharge cycles.These insights provide crucial guidance for optimizing the design and fabrication of Si–C electrode systems,enhancing their durability and performance.
基金the National Natural Science Foundation of China(22279070).
文摘In pursuit of meeting the demands for the next generation of high energy density and flexible electronic products,there is a growing interest in flexible energy storage devices.Silicon(Si)stands out as a promising electrode material due to its high theoretical specific capacity(~3579 mA h g^(-1)),low lithiation potential(~0.40 V),and abundance in nature.We have successfully developed freestanding and flexible CNT/Si/low-melting-point metal(LM)electrodes,which obviate the need for conductive additives,adhesives,and thereby increase the energy density of the device.As an anode material for lithium-ion batteries(LIBs),the CNT/Si/LM electrode demonstrates remarkable cycling stability and rate performance,achieving a reversible capacity of 1871.8 mA h g^(-1)after 100 cycles at a current density of 0.2 A g^(-1).In-situ XRD and in-situ thickness analysis are employed to elucidate the underlying mechanisms during the lithiation/delithiation.Density functional theory(DFT)calculations further substantiate the mechanism by which LM enhances the electrochemical performance of Si,focusing on the aspects of stress mitigation and reduction of the diffusion energy barrier.This research introduces a novel approach to flexible electrode design by integrating CNT films,LM,and Si,thereby charting a path forward for the development of next-generation flexible LIBs.
基金supported by the Materials/Parts Technology Development Programs(RS-2024-00466920,RS-2024-00432627,and RS-2024-00421058)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘Rapid developments in lithium-ion battery(LIB)technology have been fueled by the expanding market for electric vehicles and increased demands for energy storage.Recently,thick electrode fabrication by solvent-free methods has emerged as a promising strategy for enhancing the energy density of LIBs.However,as electrode thickness increases,the tortuosity of lithium-ion transport also increases,resulting in severe polarization and poor electrochemical performance.Here,we investigate the effect of conductive agent morphology on the structural and electrochemical properties of 250μm thick lithium iron phosphate(LFP)/conductive agent/polytetrafluoroethylene(PTFE)-based electrodes.Three commercially available conductive additives,namely 0D Super P,1D multi-walled carbon nanotubes(MWCNTs),and 2D graphene nanoplatelets(GNPs),were incorporated into LFP-based electrodes.The MWCNT-incorporated electrode with a high loading mass(42 mg cm^(-2))exhibited a high porosity(ε=51%)and low tortuosity(τ=4.02)owing to its highly interconnected fibrous network of MWCNTs.Due to the fast lithium-ion transport kinetics in the MWCNT-incorporated electrode,the electrochemical performances exhibited a high specific capacity of 157 mAh g^(-1)at 0.1 C and an areal capacity of 7.16 mAh cm^(-2)at 0.1 C with a high-rate capability and excellent cycling stability over 300 cycles at 0.1 C.This study provides a guidance for utilizing conductive agents to apply in the low tortuous thick electrode fabricated by a solvent-free process.Additionally,this work paves the way to achieve scalable and sustainable dry processing techniques for developing next-generation energy storage technologies.
