Aqueous Zinc-based energy storage devices are considered as one of the potential candidates in future power technologies.Nevertheless,poor low temperature performance and uncontrollable Zn dendrite growth lead to the ...Aqueous Zinc-based energy storage devices are considered as one of the potential candidates in future power technologies.Nevertheless,poor low temperature performance and uncontrollable Zn dendrite growth lead to the limited energy storage capability.Herein,an anti-hydrolysis,cold-resistant,economical,safe,and environmentally friendly electrolyte is developed by utilizing water,ethylene glycol(EG),and ZnCl_(2)with high ionic conductivity(7.9 mS cm^(-1)in glass fiber membrane at-20℃).The spectra data and DFT calculations show the competitive coordination of EG and Cl-to induce a unique solvation configuration of Zn^(2+),conducive to effectively inhibiting the hydrolysis of Zn^(2+),suppressing the dendrite growth,and broadening the working voltage range and temperature range of ZnCl_(2)electrolyte.The isotope tracing data confirm that Cl^(-)could effectively destroy the ZnO passivation film,promoting the formation of Zn nuclei and improving its reaction activity.Compared to the corresponding ZnSO4electrolyte,the Cu/Zn half-cell with the ZnCl_(2)electrolyte exhibits a stable cycle life of more than 1600 h at-20℃,even at the current density of 5 mA cm^(-2).The assembled Zn-ion hybrid capacitor possesses an average capacity of 42.68 m A h g^(-1)under-20℃at a current density of 5 A g^(-1),3.5 times than that of the modified ZnSO4electrolyte.Our work proposes a new approach for optimizing aqueous electrolytes to meet low temperature energy storage applications.展开更多
In this paper,we consider the double-satellite localization under the earth ellipsoid model of the Wideband Geodetic System(WGS-84)using the Time Difference of Arrival(TDOA)and the Angle-of-Arrival(AOA).Several closed...In this paper,we consider the double-satellite localization under the earth ellipsoid model of the Wideband Geodetic System(WGS-84)using the Time Difference of Arrival(TDOA)and the Angle-of-Arrival(AOA).Several closed-form solution algorithms via the pseudolinearization of the measurement equations are presented to efficiently estimate the location.These algorithms include the Weighted Least Squares(WLS),the Constrained Total Least Squares(CTLS),and the Taylor-Series Iteration(TSI).Performance comparison of the proposed methods with the Cramér-Rao Lower Bound(CRLB)in the simulation is shown to demonstrate that the proposed algorithms are feasible and have stable performance.展开更多
In this study, diamond films were synthesized on silicon substrates by microwave plasma enhanced chemical vapor deposition（CVD） over a wide range of experimental parameters. The effects of the microwave power,CH;/H;...In this study, diamond films were synthesized on silicon substrates by microwave plasma enhanced chemical vapor deposition（CVD） over a wide range of experimental parameters. The effects of the microwave power,CH;/H;ratio and gas pressure on the morphology, growth rate, composition, and quality of diamond films were investigated by means of scanning electron microscope（SEM）, X-ray diffraction（XRD）, Raman spectroscopy and X-ray photoelectron spectroscopy（XPS）. A rise of microwave power can lead to an increasing pyrolysis of hydrogen and methane, so that the microcrystalline diamond film could be synthesized at low CH;/H;levels. Gas pressure has similar effect in changing the morphology of diamond films, and high gas pressure also results in dramatically increased grain size. However,diamond film is deteriorated at high CH;/H;ratio due to the abundant graphite content including in the films. Under an extreme condition of high microwave power of 10 kW and high CH;concentration, a hybrid film composed of diamond/graphite was successfully formed in the absence of N;or Ar,which is different from other reports. This composite structure has an excellent measured sheet resistance of 10-100 Ω/Sqr. which allows it to be utilized as field electron emitter. The diamond/graphite hybrid nanostructure displays excellent electron field emission（EFE） properties with a low turn-on field of 2.17 V/μm and β= 3160, therefore it could be a promising alternative in field emission applications.展开更多
基金supported by the National Natural Science Foundation of China(52002052)the Startup funds of Outstanding Talents of UESTC(A1098531023601205)+1 种基金the National Youth Talents Plan of China(G05QNQR049)the Foundation of State Key Laboratory of Silicon Materials(SKL2021-12)。
文摘Aqueous Zinc-based energy storage devices are considered as one of the potential candidates in future power technologies.Nevertheless,poor low temperature performance and uncontrollable Zn dendrite growth lead to the limited energy storage capability.Herein,an anti-hydrolysis,cold-resistant,economical,safe,and environmentally friendly electrolyte is developed by utilizing water,ethylene glycol(EG),and ZnCl_(2)with high ionic conductivity(7.9 mS cm^(-1)in glass fiber membrane at-20℃).The spectra data and DFT calculations show the competitive coordination of EG and Cl-to induce a unique solvation configuration of Zn^(2+),conducive to effectively inhibiting the hydrolysis of Zn^(2+),suppressing the dendrite growth,and broadening the working voltage range and temperature range of ZnCl_(2)electrolyte.The isotope tracing data confirm that Cl^(-)could effectively destroy the ZnO passivation film,promoting the formation of Zn nuclei and improving its reaction activity.Compared to the corresponding ZnSO4electrolyte,the Cu/Zn half-cell with the ZnCl_(2)electrolyte exhibits a stable cycle life of more than 1600 h at-20℃,even at the current density of 5 mA cm^(-2).The assembled Zn-ion hybrid capacitor possesses an average capacity of 42.68 m A h g^(-1)under-20℃at a current density of 5 A g^(-1),3.5 times than that of the modified ZnSO4electrolyte.Our work proposes a new approach for optimizing aqueous electrolytes to meet low temperature energy storage applications.
基金supported by Meteorological information and Signal Processing Key Laboratory of Sichuan Higher Education Institutes of Chengdu University of Information Technology,China(No.QXXCSYS201702)
文摘In this paper,we consider the double-satellite localization under the earth ellipsoid model of the Wideband Geodetic System(WGS-84)using the Time Difference of Arrival(TDOA)and the Angle-of-Arrival(AOA).Several closed-form solution algorithms via the pseudolinearization of the measurement equations are presented to efficiently estimate the location.These algorithms include the Weighted Least Squares(WLS),the Constrained Total Least Squares(CTLS),and the Taylor-Series Iteration(TSI).Performance comparison of the proposed methods with the Cramér-Rao Lower Bound(CRLB)in the simulation is shown to demonstrate that the proposed algorithms are feasible and have stable performance.
基金financial support from the Project supported by the National Natural Science Foundation of China(Grant No.51202257)Shenyang Double-Hundreds Project(Z17-7-027,Z18-0-025)
文摘In this study, diamond films were synthesized on silicon substrates by microwave plasma enhanced chemical vapor deposition（CVD） over a wide range of experimental parameters. The effects of the microwave power,CH;/H;ratio and gas pressure on the morphology, growth rate, composition, and quality of diamond films were investigated by means of scanning electron microscope（SEM）, X-ray diffraction（XRD）, Raman spectroscopy and X-ray photoelectron spectroscopy（XPS）. A rise of microwave power can lead to an increasing pyrolysis of hydrogen and methane, so that the microcrystalline diamond film could be synthesized at low CH;/H;levels. Gas pressure has similar effect in changing the morphology of diamond films, and high gas pressure also results in dramatically increased grain size. However,diamond film is deteriorated at high CH;/H;ratio due to the abundant graphite content including in the films. Under an extreme condition of high microwave power of 10 kW and high CH;concentration, a hybrid film composed of diamond/graphite was successfully formed in the absence of N;or Ar,which is different from other reports. This composite structure has an excellent measured sheet resistance of 10-100 Ω/Sqr. which allows it to be utilized as field electron emitter. The diamond/graphite hybrid nanostructure displays excellent electron field emission（EFE） properties with a low turn-on field of 2.17 V/μm and β= 3160, therefore it could be a promising alternative in field emission applications.
