Advancing high-voltage stability of layered sodium-ion oxides represents a pivotal avenue for their progress in energy storage applications.Despite this,a comprehensive understanding of the mechanisms underpinning the...Advancing high-voltage stability of layered sodium-ion oxides represents a pivotal avenue for their progress in energy storage applications.Despite this,a comprehensive understanding of the mechanisms underpinning their structural deterioration at elevated voltages remains insufficiently explored.In this study,we unveil a layer delamination phenomenon of Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2)(NNM)within the 2.0-4.3 V voltage,attributed to considerable volumetric fluctuations along the c-axis and lattice oxygen reactions induced by the simultaneous Ni^(3+)/Ni^(4+)and anion redox reactions.By introducing Mg doping to diminished Ni-O antibonding,the anion oxidation-reduction reactions are effectively mitigated,and the structural integrity of the P2 phase remains firmly intact,safeguarding active sites and precluding the formation of novel interfaces.The Na_(0.67)Mg_(0.05)Ni_(0.25)Mn_(0.7)O_(2)(NMNM-5)exhibits a specific capacity of100.7 mA h g^(-1),signifying an 83%improvement compared to the NNM material within the voltage of2.0-4.3 V.This investigation underscores the intricate interplay between high-voltage stability and structural degradation mechanisms in layered sodium-ion oxides.展开更多
In order to investigate the general reliability assessment methods based on performance degradation data,two commonly used stochastic process approaches,bilinear process method and random-effect model were studied.Ana...In order to investigate the general reliability assessment methods based on performance degradation data,two commonly used stochastic process approaches,bilinear process method and random-effect model were studied.Analyzing procedure and effectiveness of these two methodologies were studied and compared.Meanwhile,the two approaches were illustrated through practical applications.The residual plots and the 10th percentile curves of the two methods were presented to demonstrate the comparative results.The randomeffect model yielded more volatile residuals and a lower and unsafe 10th percentile curve.Consequently the bilinear process model can be concluded to derive more reasonable results due to its one-stage estimation property.展开更多
Power battery technology is essential to ensuring the overall performance and safety of electric vehicles.Non-invasive char-acteristic curve analysis(CCA)for lithium-ion batteries is of particular importance.CCA can p...Power battery technology is essential to ensuring the overall performance and safety of electric vehicles.Non-invasive char-acteristic curve analysis(CCA)for lithium-ion batteries is of particular importance.CCA can provide characteristic data for further applications such as state estimation and thermal runaway warning without disassembling the batteries.This paper summarizes the characteristic curves consisting of incremental curve analysis,differential voltage analysis,and differential thermal voltammetry from the perspectives of exploring the aging mechanism of batteries and constructing the data-driven model.The process of quantitative analysis of battery aging mechanism is presented and the steps of constructing data-driven models are induced.Moreover,the recent progress and application of the main features and methodologies are discussed.Finally,the applicability of battery CCA is discussed by converting non-quantifiable battery information into transportable data covering macrostate and micro-reaction information.Combined with the cloud-based battery management platform,the above-mentioned battery characteristic curves could be used as a valuable dataset to upgrade the next-generation battery management system design.展开更多
The current research of nuclear control rod drive mechanism(CRDM)movable latch only makes a simple measurement of wear mass.The wear volume and difference in various claw surfaces are ignored and the degradation mecha...The current research of nuclear control rod drive mechanism(CRDM)movable latch only makes a simple measurement of wear mass.The wear volume and difference in various claw surfaces are ignored and the degradation mechanism of each claw surface is not clear.In this paper,a detailed degradation analysis was carried out on each claw surface of movable latch combined with wear result and worn morphology.Results indicate that the boundary of carbide is preferred for corrosion because carbide presents a nobler Volta potential compared to the metal matrix or boundary region.Due to the oscillation of drive shaft between the claw surfaces of movable latch,the dominant wear mechanism on the upper surface of claw(USC)and lower surface of claw(LSC)is plastic deformation caused by impact wear.Mechanical impact wear will cause the fragmentation of carbides because of the high hardness and low ductility of carbides.Corrosion promotes the broken carbides to fall off from the metal matrix.The generated fine carbides(abrasive particles)cause extra abrasive wear on USC when the movable brings the drive shaft upward or downward.As a result,USC has a higher wear volume than LSC.This research proposes a method to evaluate the wear on the whole movable latches using a 3D full-size scanner.展开更多
基金the financial support from the National Natural Science Foundation of China(52202338)。
文摘Advancing high-voltage stability of layered sodium-ion oxides represents a pivotal avenue for their progress in energy storage applications.Despite this,a comprehensive understanding of the mechanisms underpinning their structural deterioration at elevated voltages remains insufficiently explored.In this study,we unveil a layer delamination phenomenon of Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2)(NNM)within the 2.0-4.3 V voltage,attributed to considerable volumetric fluctuations along the c-axis and lattice oxygen reactions induced by the simultaneous Ni^(3+)/Ni^(4+)and anion redox reactions.By introducing Mg doping to diminished Ni-O antibonding,the anion oxidation-reduction reactions are effectively mitigated,and the structural integrity of the P2 phase remains firmly intact,safeguarding active sites and precluding the formation of novel interfaces.The Na_(0.67)Mg_(0.05)Ni_(0.25)Mn_(0.7)O_(2)(NMNM-5)exhibits a specific capacity of100.7 mA h g^(-1),signifying an 83%improvement compared to the NNM material within the voltage of2.0-4.3 V.This investigation underscores the intricate interplay between high-voltage stability and structural degradation mechanisms in layered sodium-ion oxides.
基金National Natural Science Foundation of China(11202011)Beijing Natural Science Foundation(3154034)+1 种基金Fundamental Research Funds for the Central Universities(YWK13HK11)National Basic Research Program of China(2012CB720000)
文摘In order to investigate the general reliability assessment methods based on performance degradation data,two commonly used stochastic process approaches,bilinear process method and random-effect model were studied.Analyzing procedure and effectiveness of these two methodologies were studied and compared.Meanwhile,the two approaches were illustrated through practical applications.The residual plots and the 10th percentile curves of the two methods were presented to demonstrate the comparative results.The randomeffect model yielded more volatile residuals and a lower and unsafe 10th percentile curve.Consequently the bilinear process model can be concluded to derive more reasonable results due to its one-stage estimation property.
基金The National Key Research and Development Program of China(2018YFB0104001-01)National Natural Science Foundation of China(No.52102470).
文摘Power battery technology is essential to ensuring the overall performance and safety of electric vehicles.Non-invasive char-acteristic curve analysis(CCA)for lithium-ion batteries is of particular importance.CCA can provide characteristic data for further applications such as state estimation and thermal runaway warning without disassembling the batteries.This paper summarizes the characteristic curves consisting of incremental curve analysis,differential voltage analysis,and differential thermal voltammetry from the perspectives of exploring the aging mechanism of batteries and constructing the data-driven model.The process of quantitative analysis of battery aging mechanism is presented and the steps of constructing data-driven models are induced.Moreover,the recent progress and application of the main features and methodologies are discussed.Finally,the applicability of battery CCA is discussed by converting non-quantifiable battery information into transportable data covering macrostate and micro-reaction information.Combined with the cloud-based battery management platform,the above-mentioned battery characteristic curves could be used as a valuable dataset to upgrade the next-generation battery management system design.
基金Supported by Sichuan Science and Technology Program(Grant No.2019ZDZX0001)National Natural Science Foundation of China(Grant No.U2067221)Sichuan Science and Technology Planning Project(Grant No.22JCQN0111).
文摘The current research of nuclear control rod drive mechanism(CRDM)movable latch only makes a simple measurement of wear mass.The wear volume and difference in various claw surfaces are ignored and the degradation mechanism of each claw surface is not clear.In this paper,a detailed degradation analysis was carried out on each claw surface of movable latch combined with wear result and worn morphology.Results indicate that the boundary of carbide is preferred for corrosion because carbide presents a nobler Volta potential compared to the metal matrix or boundary region.Due to the oscillation of drive shaft between the claw surfaces of movable latch,the dominant wear mechanism on the upper surface of claw(USC)and lower surface of claw(LSC)is plastic deformation caused by impact wear.Mechanical impact wear will cause the fragmentation of carbides because of the high hardness and low ductility of carbides.Corrosion promotes the broken carbides to fall off from the metal matrix.The generated fine carbides(abrasive particles)cause extra abrasive wear on USC when the movable brings the drive shaft upward or downward.As a result,USC has a higher wear volume than LSC.This research proposes a method to evaluate the wear on the whole movable latches using a 3D full-size scanner.