Generation characteristics of vacuum discharge plasma are very important for the applied research of metal plasma. The vacuum discharge electrode configuration and the cathode material affect the generation characteri...Generation characteristics of vacuum discharge plasma are very important for the applied research of metal plasma. The vacuum discharge electrode configuration and the cathode material affect the generation characteristics of the metal plasma which consists of metal ions coming from cathode and generated by vacuum discharge. In this research, the generation characteristics of the metal plasma generated by vacuum discharge are discussed for four patterns of electrode configurations, i.e. cone-mesh electrode setup, cone-cross line electrode setup, cone-line electrode setup and cone-ring electrode setup. Characteristics of the metal plasma, such as elec- tron density, electron temperature, space potential, ion energy, are measured by the probe method for discussing the impacts of different electrode configurations on the density of generated metal plasma. Moreover, the diffusion velocities of the metal plasma are measured for cathode materials of Pb, Al, and Cu, respectively. The experimental results indicate that the plasma generated by the discharge of cone-ring electrode configuration possesses the maximum density and the metal plasma generated by the Al cathode possesses the fastest diffusion velocity and the highest kinetic energy.展开更多
The enhanced volume of thermal plasma is produced by a multi-arc thermal plasma generator with three pairs of discharge electrodes driven by three directed current power suppliers.Combined with a high-speed camera and...The enhanced volume of thermal plasma is produced by a multi-arc thermal plasma generator with three pairs of discharge electrodes driven by three directed current power suppliers.Combined with a high-speed camera and an oscilloscope,which acquire optical and electric signals synchronously,the dynamic behavior of different kinds of multi-arc discharge adjusted by the electrode arrangement is investigated.Also,the spatial distributions and instability of the arc discharge are analyzed in four electrode configurations using the gray value statistical method.It is found that the cathodic arcs mainly show a contracting state,while the anodic arcs have a trend of transition from shrinkage to a diffusion-like state with the increase of the discharge current.As a result of the adjustment of the electrode configuration,a high temperature region formed in the center of the discharge region in configurations of adjacent electrodes with opposite flow distribution and opposite electrodes with swirl flow distribution due to severe fluctuation of arcs.The discharge voltage rises with increased discharge current in this novel multi-arc plasma generator.It is also found that anode ablation mainly occurs on the conical surface at the copper electrode tip,while cathode erosion mainly occurs on the surface of the inserted tungsten and the nearby copper.展开更多
This study investigates the breakdown voltage characteristics in sulfur hexafluoride(SF6)circuit breakers,employing a novel approach that integrates both experimental investigations and finite element simulations.Util...This study investigates the breakdown voltage characteristics in sulfur hexafluoride(SF6)circuit breakers,employing a novel approach that integrates both experimental investigations and finite element simulations.Utilizing a sphere-sphere electrode configuration,we meticulously measured the relationship between breakdown voltage and electrode gap distances ranging from 1 cm to 4.5 cm.Subsequent simulations,conducted using COMSOL Multiphysics,mirrored the experimental setup to validate the model’s accuracy through a comparison of the breakdown voltage-electrode gap distance curves.The simulation results not only aligned closely with the experimental data but also allowed the extraction of detailed electric field strength,electric potential contours,and electric current flow curves at the breakdown voltage for gap distances extending from 1 to 4.5 cm.Extending the analysis,the study explored the electric field and potential distribution at a constant voltage of 72.5 kV for gap distances between 1 to 10 cm,identifying the maximum electric field strength.A comprehensive comparison of five different electrode configurations(sphere-sphere,sphere-rod,sphere-plane,rod-plane,rod-rod)at 72.5 kV and a gap distance of 1.84 cm underscored the significant influence of electrode geometry on the breakdown process.Moreover,the research contrasts the breakdown voltage in SF6 with that in air,emphasizing SF6’s superior insulating properties.This investigation not only elucidates the intricate dynamics of electrical breakdown in SF6 circuit breakers but also contributes valuable insights into the optimal electrode configurations and the potential for alternative insulating gases,steering future advancements in high-voltage circuit breaker technology.展开更多
As an improvement on the conventional two-layer electrode （active material layerlcurrent collector）, a novel sandwich-like three-layer electrode （conductive layerlactive material layertcurrent collector） for catho...As an improvement on the conventional two-layer electrode （active material layerlcurrent collector）, a novel sandwich-like three-layer electrode （conductive layerlactive material layertcurrent collector） for cathode material LiFePO4/C was introduced in order to improve its electrochemical performance. LiFePO4/C in the three-layer electrode exhibited superior rate capability in comparison with that in the two-layer electrode in accordance with charge-discharge examination. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that Fe3＋/Fe2＋ redox couple for LiFePO4 in the three-layer electrode displayed faster kinetics, better reversibility and much lower charge transfer resistance than that in the two-layer electrode in electrochemical process. For three-layer electrode, the holes in the surface of active material layer were filled by smaller acetylene black grains, which formed electrical connections and provided more pathways to electron transport to/from LiFePO4/C particles exposed to the bulk electrolyte.展开更多
A macroscopic cell and three-dimensional fluid model have been used to investigate the discharge characteristics in ac plasma display panel cells of electrode-shaping configurations. Four kinds of non-standaxd geometr...A macroscopic cell and three-dimensional fluid model have been used to investigate the discharge characteristics in ac plasma display panel cells of electrode-shaping configurations. Four kinds of non-standaxd geometries （i.e. D-, △-, W- and U-shape electrodes） have been considered. The characteristics of the discharge current, the operating voltage and the discharge efficiency of different configurations have been discussed. It is found that the discharge efficiency can be improved by about 10%-30% compared with the standard geometry, while the operating voltage increases slightly in the non-standard geometries. There is a trade-off between improving the discharge efficiency and lowering the sustaining voltage in design of plasma display cells by electrode shaping.展开更多
Sodium ion batteries(SIBs)have been regarded as one of the alternatives to lithium ion batteries owing to their wide availability and significantly low cost of sodium sources.However,they face serious challenges of lo...Sodium ion batteries(SIBs)have been regarded as one of the alternatives to lithium ion batteries owing to their wide availability and significantly low cost of sodium sources.However,they face serious challenges of low energy&power density and short cycling lifespan owing to the heavy mass and large radius of Na^(+).Vanadium-based polyanionic compounds have advantageous characteristic of high operating voltage,high ionic conductivity and robust structural framework,which is conducive to their high energy&power density and long lifespan for SIBs.In this review,we will overview the latest V-based polyanionic compounds,along with the respective characteristic from the intrinsic crystal structure to performance presentation and improvement for SIBs.One of the most important aspect is to discover the essential problems existed in the present V-based polyanionic compounds for high-energy&power applications,and point out most suitable solutions from the crystal structure modulation,interface tailoring and electrode configuration design.Moreover,some scientific issues of V-based polyanionic compounds shall be also proposed and related future direction shall be provided.We believe that this review can serve as a motivation for further development of novel V-based polyanionic compounds and drive them toward high energy&power applications in the near future.展开更多
Flexible energy storage systems are promising and efficient technologies for realizing large-scale application of portable,bendable,and wearable electronic devices.Among these systems,aqueous hybrid supercapacitors(AH...Flexible energy storage systems are promising and efficient technologies for realizing large-scale application of portable,bendable,and wearable electronic devices.Among these systems,aqueous hybrid supercapacitors(AHSs)fabricated using redox-active materials with a positive voltage window in aqueous electrolytes and capacitive carbon materials have attracted enormous attention due to their advantages,including a wide operating voltage,a high energy density,a high power density,a long cycling lifespan,and low cost.Thus far,considerable efforts have been made to develop flexible AHSs constructed from various free-standing and flexible electrodes.However,optimizing the configurations of flexible electrodes and the interfacial interaction between flexible substrates and electroactive materials to fully develop the performance through their synergistic effects remains a major challenge.Herein,we have reviewed and summarized recent advances in flexible electrode materials with a variety of configurations based on porous metal supports,carbon substrates,including carbon nanotube networks,graphene and wearable carbon(carbon fibers,carbon cloth,carbon fabric,etc.),and other flexible materials for high-performance AHSs.These flexible electrodes show unique configurations and optimized interfacial structures,resulting in excellent electrochemical performance and superior mechanical stability in AHSs under various harsh conditions,and have great potential for practical applications.Furthermore,the future directions and perspectives for constructing flexible electrodes with novel configurations and AHSs are outlined and discussed,including(1)fabrication of compressible,ultralight,or transparent flexible electrodes for special needs;(2)tailoring and tuning of interfacial properties with robust adhesion between electroactive materials and flexible substrates;(3)development of advanced in situ characterization techniques to uncover the structure evolution rules of flexible electrodes under the operation conditions;(4)matching and optimization of flexible positive and negative electrode materials to assemble advanced AHS devices;(5)design of multifunctional flexible electrodes and AHSs by integrating other specific functions,etc.This timely review is believed to provide deep insights into the intensive research on flexible aqueous energy storage devices.展开更多
Three‐dimensional(3D)printing has the potential to revolutionize the way energy storage devices are designed and manufactured.In this paper,we explore the use of 3D printing in the design and production of energy sto...Three‐dimensional(3D)printing has the potential to revolutionize the way energy storage devices are designed and manufactured.In this paper,we explore the use of 3D printing in the design and production of energy storage devices,especially zinc‐ion batteries(ZIBs)and examine its potential advantages over traditional manufacturing methods.3D printing could significantly improve the customization of ZIBs,making it a promising strategy for the future of energy storage.In particular,3D printing allows for the creation of complex,customized geometries,and designs that can optimize the energy density,power density,and overall performance of batteries.Simultaneously,we discuss and compare the impact of 3D printing design strategies based on different configurations of film,interdigitation,and framework on energy storage devices with a focus on ZIBs.Additionally,3D printing enables the rapid prototyping and production of batteries,reducing leading times and costs compared with traditional manufacturing methods.However,there are also challenges and limitations to consider,such as the need for further development of suitable 3D printing materials and processes for energy storage applications.展开更多
文摘Generation characteristics of vacuum discharge plasma are very important for the applied research of metal plasma. The vacuum discharge electrode configuration and the cathode material affect the generation characteristics of the metal plasma which consists of metal ions coming from cathode and generated by vacuum discharge. In this research, the generation characteristics of the metal plasma generated by vacuum discharge are discussed for four patterns of electrode configurations, i.e. cone-mesh electrode setup, cone-cross line electrode setup, cone-line electrode setup and cone-ring electrode setup. Characteristics of the metal plasma, such as elec- tron density, electron temperature, space potential, ion energy, are measured by the probe method for discussing the impacts of different electrode configurations on the density of generated metal plasma. Moreover, the diffusion velocities of the metal plasma are measured for cathode materials of Pb, Al, and Cu, respectively. The experimental results indicate that the plasma generated by the discharge of cone-ring electrode configuration possesses the maximum density and the metal plasma generated by the Al cathode possesses the fastest diffusion velocity and the highest kinetic energy.
基金supported by National Natural Science Foundation of China(No.11875295)the National Key R&D Program of China(No.2019YFC0119000)。
文摘The enhanced volume of thermal plasma is produced by a multi-arc thermal plasma generator with three pairs of discharge electrodes driven by three directed current power suppliers.Combined with a high-speed camera and an oscilloscope,which acquire optical and electric signals synchronously,the dynamic behavior of different kinds of multi-arc discharge adjusted by the electrode arrangement is investigated.Also,the spatial distributions and instability of the arc discharge are analyzed in four electrode configurations using the gray value statistical method.It is found that the cathodic arcs mainly show a contracting state,while the anodic arcs have a trend of transition from shrinkage to a diffusion-like state with the increase of the discharge current.As a result of the adjustment of the electrode configuration,a high temperature region formed in the center of the discharge region in configurations of adjacent electrodes with opposite flow distribution and opposite electrodes with swirl flow distribution due to severe fluctuation of arcs.The discharge voltage rises with increased discharge current in this novel multi-arc plasma generator.It is also found that anode ablation mainly occurs on the conical surface at the copper electrode tip,while cathode erosion mainly occurs on the surface of the inserted tungsten and the nearby copper.
基金Ningbo Science and Technology Plan Project(Grant No.2023Z043)。
文摘This study investigates the breakdown voltage characteristics in sulfur hexafluoride(SF6)circuit breakers,employing a novel approach that integrates both experimental investigations and finite element simulations.Utilizing a sphere-sphere electrode configuration,we meticulously measured the relationship between breakdown voltage and electrode gap distances ranging from 1 cm to 4.5 cm.Subsequent simulations,conducted using COMSOL Multiphysics,mirrored the experimental setup to validate the model’s accuracy through a comparison of the breakdown voltage-electrode gap distance curves.The simulation results not only aligned closely with the experimental data but also allowed the extraction of detailed electric field strength,electric potential contours,and electric current flow curves at the breakdown voltage for gap distances extending from 1 to 4.5 cm.Extending the analysis,the study explored the electric field and potential distribution at a constant voltage of 72.5 kV for gap distances between 1 to 10 cm,identifying the maximum electric field strength.A comprehensive comparison of five different electrode configurations(sphere-sphere,sphere-rod,sphere-plane,rod-plane,rod-rod)at 72.5 kV and a gap distance of 1.84 cm underscored the significant influence of electrode geometry on the breakdown process.Moreover,the research contrasts the breakdown voltage in SF6 with that in air,emphasizing SF6’s superior insulating properties.This investigation not only elucidates the intricate dynamics of electrical breakdown in SF6 circuit breakers but also contributes valuable insights into the optimal electrode configurations and the potential for alternative insulating gases,steering future advancements in high-voltage circuit breaker technology.
基金Project(2010ZCO51)supported by Natural Science Foundation of Yunnan ProvinceProject supported by Analysis and Testing Foundation(2009-041)Starting Research Fund(14118245)from Kunming University of Science and Technology
文摘As an improvement on the conventional two-layer electrode （active material layerlcurrent collector）, a novel sandwich-like three-layer electrode （conductive layerlactive material layertcurrent collector） for cathode material LiFePO4/C was introduced in order to improve its electrochemical performance. LiFePO4/C in the three-layer electrode exhibited superior rate capability in comparison with that in the two-layer electrode in accordance with charge-discharge examination. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that Fe3＋/Fe2＋ redox couple for LiFePO4 in the three-layer electrode displayed faster kinetics, better reversibility and much lower charge transfer resistance than that in the two-layer electrode in electrochemical process. For three-layer electrode, the holes in the surface of active material layer were filled by smaller acetylene black grains, which formed electrical connections and provided more pathways to electron transport to/from LiFePO4/C particles exposed to the bulk electrolyte.
基金Project supported by the National Natural Science Foundation of China （Grant No 10475007）, the Scientific Research Foundation for the Returned 0verseas Chinese Scholars, the State Education Ministry of China （Grant No LLKYJJ200403） and Thomson . Plasma, France.
文摘A macroscopic cell and three-dimensional fluid model have been used to investigate the discharge characteristics in ac plasma display panel cells of electrode-shaping configurations. Four kinds of non-standaxd geometries （i.e. D-, △-, W- and U-shape electrodes） have been considered. The characteristics of the discharge current, the operating voltage and the discharge efficiency of different configurations have been discussed. It is found that the discharge efficiency can be improved by about 10%-30% compared with the standard geometry, while the operating voltage increases slightly in the non-standard geometries. There is a trade-off between improving the discharge efficiency and lowering the sustaining voltage in design of plasma display cells by electrode shaping.
基金financial support from the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA21070500)the DNL Cooperation Fund,CAS(DNL201914)。
文摘Sodium ion batteries(SIBs)have been regarded as one of the alternatives to lithium ion batteries owing to their wide availability and significantly low cost of sodium sources.However,they face serious challenges of low energy&power density and short cycling lifespan owing to the heavy mass and large radius of Na^(+).Vanadium-based polyanionic compounds have advantageous characteristic of high operating voltage,high ionic conductivity and robust structural framework,which is conducive to their high energy&power density and long lifespan for SIBs.In this review,we will overview the latest V-based polyanionic compounds,along with the respective characteristic from the intrinsic crystal structure to performance presentation and improvement for SIBs.One of the most important aspect is to discover the essential problems existed in the present V-based polyanionic compounds for high-energy&power applications,and point out most suitable solutions from the crystal structure modulation,interface tailoring and electrode configuration design.Moreover,some scientific issues of V-based polyanionic compounds shall be also proposed and related future direction shall be provided.We believe that this review can serve as a motivation for further development of novel V-based polyanionic compounds and drive them toward high energy&power applications in the near future.
基金supported by the National Natural Science Foundation of China(Nos.22278328,U2003216)the Key Research and Development Program in Shaanxi Province of China(No.2023-YBGY-292)the Fundamental Research Funds for the Central Universities(No.xtr042021009).
文摘Flexible energy storage systems are promising and efficient technologies for realizing large-scale application of portable,bendable,and wearable electronic devices.Among these systems,aqueous hybrid supercapacitors(AHSs)fabricated using redox-active materials with a positive voltage window in aqueous electrolytes and capacitive carbon materials have attracted enormous attention due to their advantages,including a wide operating voltage,a high energy density,a high power density,a long cycling lifespan,and low cost.Thus far,considerable efforts have been made to develop flexible AHSs constructed from various free-standing and flexible electrodes.However,optimizing the configurations of flexible electrodes and the interfacial interaction between flexible substrates and electroactive materials to fully develop the performance through their synergistic effects remains a major challenge.Herein,we have reviewed and summarized recent advances in flexible electrode materials with a variety of configurations based on porous metal supports,carbon substrates,including carbon nanotube networks,graphene and wearable carbon(carbon fibers,carbon cloth,carbon fabric,etc.),and other flexible materials for high-performance AHSs.These flexible electrodes show unique configurations and optimized interfacial structures,resulting in excellent electrochemical performance and superior mechanical stability in AHSs under various harsh conditions,and have great potential for practical applications.Furthermore,the future directions and perspectives for constructing flexible electrodes with novel configurations and AHSs are outlined and discussed,including(1)fabrication of compressible,ultralight,or transparent flexible electrodes for special needs;(2)tailoring and tuning of interfacial properties with robust adhesion between electroactive materials and flexible substrates;(3)development of advanced in situ characterization techniques to uncover the structure evolution rules of flexible electrodes under the operation conditions;(4)matching and optimization of flexible positive and negative electrode materials to assemble advanced AHS devices;(5)design of multifunctional flexible electrodes and AHSs by integrating other specific functions,etc.This timely review is believed to provide deep insights into the intensive research on flexible aqueous energy storage devices.
基金Xuan Gao thanked the funding support from China Scholarship Council/University College London for the joint PhD scholarshipThe authors would like to acknowledge the Engineering and Physical Sciences Research Council,United Kingdom(EPSRC,Nos.EP/L015862/1,EP/V027433/1,and EP/V027433/2).
文摘Three‐dimensional(3D)printing has the potential to revolutionize the way energy storage devices are designed and manufactured.In this paper,we explore the use of 3D printing in the design and production of energy storage devices,especially zinc‐ion batteries(ZIBs)and examine its potential advantages over traditional manufacturing methods.3D printing could significantly improve the customization of ZIBs,making it a promising strategy for the future of energy storage.In particular,3D printing allows for the creation of complex,customized geometries,and designs that can optimize the energy density,power density,and overall performance of batteries.Simultaneously,we discuss and compare the impact of 3D printing design strategies based on different configurations of film,interdigitation,and framework on energy storage devices with a focus on ZIBs.Additionally,3D printing enables the rapid prototyping and production of batteries,reducing leading times and costs compared with traditional manufacturing methods.However,there are also challenges and limitations to consider,such as the need for further development of suitable 3D printing materials and processes for energy storage applications.
