NaCu_(0.2)Fe_(0.3)Mn_(0.5)O_(2) (NCFM) cathode material was synthesized using a simple solid-state reaction, and the effect of calcination temperature on its interlayer spacing and oxygen vacancies concentration was i...NaCu_(0.2)Fe_(0.3)Mn_(0.5)O_(2) (NCFM) cathode material was synthesized using a simple solid-state reaction, and the effect of calcination temperature on its interlayer spacing and oxygen vacancies concentration was investigated. Through electrochemical testing and material characterizations, higher calcination temperatures increase the electrostatic repulsion between oxygen atoms in adjacent layers, resulting in an expansion of Na layer spacing. This structural change enhances the diffusion kinetics of Na^(+), thereby significantly improving the rate performance of NCFM. Furthermore, elevated calcination temperatures facilitate the reduction of oxygen vacancies, leading to improved crystallinity. This enhancement in crystallinity mitigates structural strain during phase transitions, contributing to improved cyclic stability. Consequently, the optimized NCFM shows an initial discharge specific capacity of 143.3 mA·h/g at 0.1C, with a capacity retention rate of 79.28% after 100 cycles at 1C.展开更多
The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and redu...The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and reduce forming loads.However,the absence of compatible forming equipment makes it difficult to control the constraint in the unloaded zones during the forming process.This difficulty complicates coordination and control of deformation,particularly for asymmetric rib-web components.Additionally,the current implementation involves multi-fire heating,a long process flow,and high energy consumption,which limits the popularization and application of the local loading process.In this study,a new multi-pass local loading hydraulic forming apparatus that can quickly and reliably switch between heavy-load deformation and low-load constraint for different local loading sub-dies was developed.A 10-tonne laboratory prototype was developed,and the forming characteristics during the forming process as well as the response characteristics of the hydraulic system during the multi-pass intermittent local loading of rib-web component were investigated using numerical simulations and physical experiments.Results indicated that,compared to a whole loading process with the same initial geometry of billet,the total forming load(i.e.,the sum of loaded and restrained loads)is reduced by more than 40%with the local loading process,and by nearly 50%with multi-pass local loading.The multi-pass local loading process allows for more effective control of material flow compared to single-pass local loading,leading to improved cavity filling and reduced flow line disturbance.For a large-scale,complex titanium alloy bulkhead,the cavity filling problem was addressed by optimizing the multi-pass local loading path with an unequal thickness billet.The dynamic performance of the multi-pass local loading hydraulic system was found to be robust,with stable pressure transitions during motion and load switching for the sub-die(s).The dynamic characteristic of the hydraulic cylinder when switching from non-moving/unloaded state to a moving/loading state are consistent whether a load is present or not.However,the dynamic characteristics differ when switching from a moving/loading state to non-moving/unloaded state,showing opposite behavior.The developed hydraulic drive mechanism provides a way for implementation of multi-pass local loading without auxiliary operation and extra heating.The results of the study provide a foundation for the industrial production of large-scale,complex components with reduced force requirement and low-energy consumption.展开更多
Weakly solvating electrolytes(WSEs)promote the formation of anion-driven solid electrolyte interphases(SEI),enabling stable lithium metal batteries.However,current strategies involving alkylated modification,steric hi...Weakly solvating electrolytes(WSEs)promote the formation of anion-driven solid electrolyte interphases(SEI),enabling stable lithium metal batteries.However,current strategies involving alkylated modification,steric hindrance incorporation,coordinated oxygen(O)regulation,and selective fluorination face poor-diversity interfacial chemistry,high cost,or environmental concerns.Here,we propose a heteroatom-substitution strategy to design a WSE composed of lithium bis(fluorosulfonyl)imide(LiFSI)and 1,4-oxathiane(OTA)as a single solvent.Substituting oxygen with sulfur in conventional 1,4-dioxane(1,4-DX)generates OTA with a modulated dipole and charge distribution,weakening Li^(+)-OTA coordination while promoting anion-involved solvation sheath.This unique solvation structure triggers the formation of an inorganic-rich SEI with sulfur-containing species,enabling high Li plating/stripping coulombic efficiency and stable Li‖Li symmetric cells cycling for 1000 h.Benefiting from the superior interfacial chemistry and wettability of the electrolyte to the LiFePO_(4) cathode,full cells exhibit exceptional cycling stability even at low negative-to-positive(N/P)ratios,A pouch cell coupled with3.58 mAh cm^(-2) LiFePO_(4) and 20μm Li(N/P~1.15)maintains 88.77%capacity after 150 cycles.This work shows a fluorine-free solvent design paradigm for advanced WSEs,providing novel insights toward stable LMBs.展开更多
Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)...Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)sensors.Among them,the traditional surface plasmon polariton(SPP)based on noble metals limits its application beyond the near-infrared(IR)regime due to the large negative permittivity and optical losses.In this contribution,we theoretically proposed a highly sensitive PSHE sensor with the structure of Ge prism-SiC-Si:InAs-sensing medium,by taking advantage of the hybrid surface plasmon phonon polariton(SPPhP)in mid-IR regime.Here,heavily Si-doped InAs(Si:InAs)and SiC excite the SPP and surface phonon polariton(SPhP),and the hybrid SPPhP is realized in this system.More importantly,the designed PSHE sensor based on this SPPhP mechanism achieves the multi-stage RI measurements from 1.00025-1.00225 to 1.70025-1.70225,and the maximal intensity sensitivity and angle sensitivity can be up to 9.4×10^(4)μm/RIU and245°/RIU,respectively.These findings provide a new pathway for the enhancement of PSHE in mid-IR regime,and offer new opportunities to develop highly sensitive RI sensors in multi-scenario applications,such as harmful gas monitoring and biosensing.展开更多
基金supported by the National Natural Science Foundation of China(No.12175089)the Key Research and Development Program of Yunnan Province,China(No.202103AF140006)+2 种基金Basic Research Programs of Yunnan Provincial Science and Technology Department,China(Nos.202001AW070004,202301AS070051,202401AV070008)Yunnan Industrial Innovative Talents Program for“Xingdian Talent Support Plan”,China(No.KKXY202252001)Yunnan Major Scientific and Technological Projects,China(No.202202AG050003)。
文摘NaCu_(0.2)Fe_(0.3)Mn_(0.5)O_(2) (NCFM) cathode material was synthesized using a simple solid-state reaction, and the effect of calcination temperature on its interlayer spacing and oxygen vacancies concentration was investigated. Through electrochemical testing and material characterizations, higher calcination temperatures increase the electrostatic repulsion between oxygen atoms in adjacent layers, resulting in an expansion of Na layer spacing. This structural change enhances the diffusion kinetics of Na^(+), thereby significantly improving the rate performance of NCFM. Furthermore, elevated calcination temperatures facilitate the reduction of oxygen vacancies, leading to improved crystallinity. This enhancement in crystallinity mitigates structural strain during phase transitions, contributing to improved cyclic stability. Consequently, the optimized NCFM shows an initial discharge specific capacity of 143.3 mA·h/g at 0.1C, with a capacity retention rate of 79.28% after 100 cycles at 1C.
基金the supports of the National Natural Science Foundation of China(Grant No.52375378)。
文摘The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and reduce forming loads.However,the absence of compatible forming equipment makes it difficult to control the constraint in the unloaded zones during the forming process.This difficulty complicates coordination and control of deformation,particularly for asymmetric rib-web components.Additionally,the current implementation involves multi-fire heating,a long process flow,and high energy consumption,which limits the popularization and application of the local loading process.In this study,a new multi-pass local loading hydraulic forming apparatus that can quickly and reliably switch between heavy-load deformation and low-load constraint for different local loading sub-dies was developed.A 10-tonne laboratory prototype was developed,and the forming characteristics during the forming process as well as the response characteristics of the hydraulic system during the multi-pass intermittent local loading of rib-web component were investigated using numerical simulations and physical experiments.Results indicated that,compared to a whole loading process with the same initial geometry of billet,the total forming load(i.e.,the sum of loaded and restrained loads)is reduced by more than 40%with the local loading process,and by nearly 50%with multi-pass local loading.The multi-pass local loading process allows for more effective control of material flow compared to single-pass local loading,leading to improved cavity filling and reduced flow line disturbance.For a large-scale,complex titanium alloy bulkhead,the cavity filling problem was addressed by optimizing the multi-pass local loading path with an unequal thickness billet.The dynamic performance of the multi-pass local loading hydraulic system was found to be robust,with stable pressure transitions during motion and load switching for the sub-die(s).The dynamic characteristic of the hydraulic cylinder when switching from non-moving/unloaded state to a moving/loading state are consistent whether a load is present or not.However,the dynamic characteristics differ when switching from a moving/loading state to non-moving/unloaded state,showing opposite behavior.The developed hydraulic drive mechanism provides a way for implementation of multi-pass local loading without auxiliary operation and extra heating.The results of the study provide a foundation for the industrial production of large-scale,complex components with reduced force requirement and low-energy consumption.
基金the financial support from the National Natural Science Foundation of China,China(Grant Nos.52502258 and 52162030)the Yunnan Fundamental Research Projects,China(Grant Nos.202501AT070298,202401AU070163 and 202401AT070368)+5 种基金the Yunnan Engineering Research Center Innovation Ability Construction and Enhancement Projects,China(Grant No.2023-XMDJ-00617107)the Expert Workstation Support Project of Yunnan Province,China(Grant Nos.202405AF140069 and 202505AF350019)the University Service Key Industry Project of Yunnan Province,China(Grant No.FWCY-ZD2024005)the Shenzhen Science and Technology Program,China(Grant No.KJZD20230923114107014)the Scientific Research Foundation of Kunming University of Science and Technology,China(20220122)the Analysis and Test Foundation of Kunming University of Science and Technology,China(Grant No.2023T20220122)。
文摘Weakly solvating electrolytes(WSEs)promote the formation of anion-driven solid electrolyte interphases(SEI),enabling stable lithium metal batteries.However,current strategies involving alkylated modification,steric hindrance incorporation,coordinated oxygen(O)regulation,and selective fluorination face poor-diversity interfacial chemistry,high cost,or environmental concerns.Here,we propose a heteroatom-substitution strategy to design a WSE composed of lithium bis(fluorosulfonyl)imide(LiFSI)and 1,4-oxathiane(OTA)as a single solvent.Substituting oxygen with sulfur in conventional 1,4-dioxane(1,4-DX)generates OTA with a modulated dipole and charge distribution,weakening Li^(+)-OTA coordination while promoting anion-involved solvation sheath.This unique solvation structure triggers the formation of an inorganic-rich SEI with sulfur-containing species,enabling high Li plating/stripping coulombic efficiency and stable Li‖Li symmetric cells cycling for 1000 h.Benefiting from the superior interfacial chemistry and wettability of the electrolyte to the LiFePO_(4) cathode,full cells exhibit exceptional cycling stability even at low negative-to-positive(N/P)ratios,A pouch cell coupled with3.58 mAh cm^(-2) LiFePO_(4) and 20μm Li(N/P~1.15)maintains 88.77%capacity after 150 cycles.This work shows a fluorine-free solvent design paradigm for advanced WSEs,providing novel insights toward stable LMBs.
基金Project supported by the National Natural Science Foundation of China(Grant No.12175107)the Qing Lan Project of Jiangsu Province+2 种基金the Hua Li Talents Program of Nanjing University of PostsTelecommunications,Natural Science Foundation of Nanjing Vocational University of Industry Technology(Grant No.YK22-02-08)the Fund from the Research Center of Industrial Perception and Intelligent Manufacturing Equipment Engineering of Jiangsu Province,China(Grant No.ZK21-05-09)。
文摘Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)sensors.Among them,the traditional surface plasmon polariton(SPP)based on noble metals limits its application beyond the near-infrared(IR)regime due to the large negative permittivity and optical losses.In this contribution,we theoretically proposed a highly sensitive PSHE sensor with the structure of Ge prism-SiC-Si:InAs-sensing medium,by taking advantage of the hybrid surface plasmon phonon polariton(SPPhP)in mid-IR regime.Here,heavily Si-doped InAs(Si:InAs)and SiC excite the SPP and surface phonon polariton(SPhP),and the hybrid SPPhP is realized in this system.More importantly,the designed PSHE sensor based on this SPPhP mechanism achieves the multi-stage RI measurements from 1.00025-1.00225 to 1.70025-1.70225,and the maximal intensity sensitivity and angle sensitivity can be up to 9.4×10^(4)μm/RIU and245°/RIU,respectively.These findings provide a new pathway for the enhancement of PSHE in mid-IR regime,and offer new opportunities to develop highly sensitive RI sensors in multi-scenario applications,such as harmful gas monitoring and biosensing.
