Ether-based solvents generally show better affinity for lithium metal,and thus ether-based electrolytes(EBEs)are more inclined to form a uniform and thin solid electrolyte interface(SEI),ensuring the long cycle stabil...Ether-based solvents generally show better affinity for lithium metal,and thus ether-based electrolytes(EBEs)are more inclined to form a uniform and thin solid electrolyte interface(SEI),ensuring the long cycle stability of the lithium metal batteries(LMBs).Nonetheless,EBEs still face the challenge of oxidative decomposition under high voltage,which will corrode the structure of cathodes,destroy the stability of the electrode−electrolyte interface,and even cause safety risks.Herein,the types and challenges of EBEs are reviewed,the strategies for improving the high voltage stability of EBEs and constructing stable electrode−electrolyte interfaces are discussed in detail.Finally,the future perspectives and potential directions for composition optimization of EBEs and electrolyte−electrode interface regulation of high-voltage LMBs are explored.展开更多
Proper orthogonal decomposition (POD) is an effective statistical technique for data reduction and feature extraction of the random field including the wind field. This paper introduces the theory of the POD and ill...Proper orthogonal decomposition (POD) is an effective statistical technique for data reduction and feature extraction of the random field including the wind field. This paper introduces the theory of the POD and illustrates engineering of structures. Using the POD technique, it is shown that wind pressure data can be accurately reconstructed with a limited number of modes using the wind pressure data from wind tunnel test. Comparing the reconstructed values by POD with the original measured values from the wind tunnel test both in the time and frequency domains, it is concluded that the proper orthogonal decomposition(POD) is an efficient and practical technique for deriving the random wind pressure field from limited known data as shown in the pitched roof example in this paper.展开更多
Plasma electrolytic oxidation(PEO)is considered as a cost effective and environmentally friendly surface treatmentprocess for improving surface properties of light alloys.The formation of ceramic coatings on Ti6Al4V a...Plasma electrolytic oxidation(PEO)is considered as a cost effective and environmentally friendly surface treatmentprocess for improving surface properties of light alloys.The formation of ceramic coatings on Ti6Al4V alloy was reported bytwo-step PEO process and its structural,electrochemical and mechanical properties with the coated samples were compared byone-step PEO process in an alkaline electrolyte.The structural properties were studied using field-emission scanning microscope(FESEM)and X-ray diffraction(XRD).Electrochemical studies were carried out using linear polarization method and in additionmechanical behaviors were investigated by means of Knoop microhardness and nanoindentation method.Results showed that thesecond step process resulted in an increase of both porosity percentage and average pore diameter on the surface.The two-stepprocess resulted in a small increase of thickness from about12.5to13.0μm.Electrochemical test results showed that applying thesecond step resulted in the decrease of both polarization resistance from1800.2to412.5kΩ/cm2and protection efficiency from97.8%to90.5%.Finally,the nanoindentation results indicated that the PEO coatings became softer but more ductile after applyingthe second processing step in acidic electrolyte.展开更多
Effect of configuration (structure of electrode, interelectrode gap, positions of inlet and outlet, volume of the cell and additional nets) on mass transfer characteristic of a filter-press type electrochemical cell...Effect of configuration (structure of electrode, interelectrode gap, positions of inlet and outlet, volume of the cell and additional nets) on mass transfer characteristic of a filter-press type electrochemical cell has been studied. The mass transfer coefficients on the electrodes were obtained by using the well-known technique based on the determination of limiting diffusion current. It is found that mass transfer coefficients with mesh electrode are greater than that of with plate electrode. Mass transfer coefficient is decreased with interelectrode gap. While interelectrode gap achieved a certain value (7 ram), mass transfer coefficient is steady, no more declining. Mass transfer characteristic for different positions of inlet and outlet are different and dimensionless number groups correlated equations are obtained by experiment. Mass transfer characteristic is the best when inlet located on the top and outlet on the bottom of the cell respectively. While magnified the volume of the cell to eight times, mass transfer characteristic changes little. Mass transfer characteristic without nets is lower than that of with additional nets in the exit region, but higher than that of with additional nets in the entry region.展开更多
Metallic nanowire arrays (NWAs) possess wide application prospects due to their unique property, and the tailoring of NWAs' structure and morphology is of importance since it would significantly influence the per- ...Metallic nanowire arrays (NWAs) possess wide application prospects due to their unique property, and the tailoring of NWAs' structure and morphology is of importance since it would significantly influence the per- formance of NWAs. In the present work, the morphology and structure evolution of the NWAs prepared by the newly developed die nanoimprinting technique has been investigated in detail. It was found that increasing pro- cessing temperature, time and pressure could increase the length of the nanowires and change the NWAs' morphol- ogy from monodispersed form to aggregated form. Increasing processing time and temperature within the supercooled liquid region would promote crystallization, while increasing processing pressure could suppress the crystallization. This work provided important insights into the structure and morphology evolution, and therefore, the tailoring of metallic NWAs prepared by die nanoimprinting through adjusting the process parameters.展开更多
基金financial support from the Natural Science Foundation of Hunan Province,China (No.2023JJ40759)the State Key Laboratory of Powder Metallurgy in Central South University,China。
文摘Ether-based solvents generally show better affinity for lithium metal,and thus ether-based electrolytes(EBEs)are more inclined to form a uniform and thin solid electrolyte interface(SEI),ensuring the long cycle stability of the lithium metal batteries(LMBs).Nonetheless,EBEs still face the challenge of oxidative decomposition under high voltage,which will corrode the structure of cathodes,destroy the stability of the electrode−electrolyte interface,and even cause safety risks.Herein,the types and challenges of EBEs are reviewed,the strategies for improving the high voltage stability of EBEs and constructing stable electrode−electrolyte interfaces are discussed in detail.Finally,the future perspectives and potential directions for composition optimization of EBEs and electrolyte−electrode interface regulation of high-voltage LMBs are explored.
基金Acknowledgements The authors are grateful for the support of this research by the Committee of National Science Foundation of China (50908077) and Foundation of Heilongjiang Province Educational Committee (11551368).
文摘Proper orthogonal decomposition (POD) is an effective statistical technique for data reduction and feature extraction of the random field including the wind field. This paper introduces the theory of the POD and illustrates engineering of structures. Using the POD technique, it is shown that wind pressure data can be accurately reconstructed with a limited number of modes using the wind pressure data from wind tunnel test. Comparing the reconstructed values by POD with the original measured values from the wind tunnel test both in the time and frequency domains, it is concluded that the proper orthogonal decomposition(POD) is an efficient and practical technique for deriving the random wind pressure field from limited known data as shown in the pitched roof example in this paper.
基金International affairs department of University of Tehran and Sarkhoon & Qeshm Gas Treating Company for the financial support of this study
文摘Plasma electrolytic oxidation(PEO)is considered as a cost effective and environmentally friendly surface treatmentprocess for improving surface properties of light alloys.The formation of ceramic coatings on Ti6Al4V alloy was reported bytwo-step PEO process and its structural,electrochemical and mechanical properties with the coated samples were compared byone-step PEO process in an alkaline electrolyte.The structural properties were studied using field-emission scanning microscope(FESEM)and X-ray diffraction(XRD).Electrochemical studies were carried out using linear polarization method and in additionmechanical behaviors were investigated by means of Knoop microhardness and nanoindentation method.Results showed that thesecond step process resulted in an increase of both porosity percentage and average pore diameter on the surface.The two-stepprocess resulted in a small increase of thickness from about12.5to13.0μm.Electrochemical test results showed that applying thesecond step resulted in the decrease of both polarization resistance from1800.2to412.5kΩ/cm2and protection efficiency from97.8%to90.5%.Finally,the nanoindentation results indicated that the PEO coatings became softer but more ductile after applyingthe second processing step in acidic electrolyte.
基金Supported by the National Natural Science Foundation of China (20573045, 20843001), the "Tenth Five-Year" National Key Scientific and Technological Project (2004BA313B-17) and the National High Technology Research and Development Pro gram of China (2006AA06Z321).
文摘Effect of configuration (structure of electrode, interelectrode gap, positions of inlet and outlet, volume of the cell and additional nets) on mass transfer characteristic of a filter-press type electrochemical cell has been studied. The mass transfer coefficients on the electrodes were obtained by using the well-known technique based on the determination of limiting diffusion current. It is found that mass transfer coefficients with mesh electrode are greater than that of with plate electrode. Mass transfer coefficient is decreased with interelectrode gap. While interelectrode gap achieved a certain value (7 ram), mass transfer coefficient is steady, no more declining. Mass transfer characteristic for different positions of inlet and outlet are different and dimensionless number groups correlated equations are obtained by experiment. Mass transfer characteristic is the best when inlet located on the top and outlet on the bottom of the cell respectively. While magnified the volume of the cell to eight times, mass transfer characteristic changes little. Mass transfer characteristic without nets is lower than that of with additional nets in the exit region, but higher than that of with additional nets in the entry region.
基金This work was supported by the National Natural Science Foundation of China (51271095 and 51101090), and PhD Program Foundation of Ministry of Education of China (20120002110038).
文摘Metallic nanowire arrays (NWAs) possess wide application prospects due to their unique property, and the tailoring of NWAs' structure and morphology is of importance since it would significantly influence the per- formance of NWAs. In the present work, the morphology and structure evolution of the NWAs prepared by the newly developed die nanoimprinting technique has been investigated in detail. It was found that increasing pro- cessing temperature, time and pressure could increase the length of the nanowires and change the NWAs' morphol- ogy from monodispersed form to aggregated form. Increasing processing time and temperature within the supercooled liquid region would promote crystallization, while increasing processing pressure could suppress the crystallization. This work provided important insights into the structure and morphology evolution, and therefore, the tailoring of metallic NWAs prepared by die nanoimprinting through adjusting the process parameters.