The crystal structure, the phase composition and the electrochemical characteristics of Zr0.9Ti0.1(Ni1.1Mn0.7V0.2)x (x=0.90, 0.95, 1.00, 1.05) alloys were investigated by means of XRD, SEM, EDS and electrochemical mea...The crystal structure, the phase composition and the electrochemical characteristics of Zr0.9Ti0.1(Ni1.1Mn0.7V0.2)x (x=0.90, 0.95, 1.00, 1.05) alloys were investigated by means of XRD, SEM, EDS and electrochemical measurements. It was shown that all alloys are multiphase with C15 Laves phase as a main phase along with C14 phase and some secondary phases. And the amounts of the C14 phase and secondary phases in the four alloys increases with decreasing x. The results indicated that the various stoichiometric ratios have great effects on the electrochemical characteristics such as the maximum discharge capacity, discharge rate capability and self-discharge properties etc. for Zr0.9Ti0.1(Ni1.1Mn0.7 V0.2)X (x=0.90, 0.95, 1.00, 1.05) alloys. The hyper-stoichiometric Zr0.9 Ti0.1(N1.1Mn0.7 V0.20)1.05 exhibits the maximum discharge capacity of 332mAh-g-1. The C14 phase and secondary phases seems to improve discharge rate capability of the alloys.展开更多
The degradation mechanism of electrochemical performance of sealed type nickel/metal hydride batteries was investigated. The results indicate that the degradation behavior of Ni/MH battery is not only owing to the l...The degradation mechanism of electrochemical performance of sealed type nickel/metal hydride batteries was investigated. The results indicate that the degradation behavior of Ni/MH battery is not only owing to the lack of electrolyte, but also the deterioration of the active materials on the positive and negative electrodes of Ni/MH batteries. Scanning electron micrographs (SEM), X ray diffraction (XRD) and laser granularity analyses are presented. The particle pulverization and oxidation during charge/discharge are identified as the main causes for deterioration of the negative and positive electrode in nickel/metal hydride batteries, as well as the cross section cracking of both anode and cathode.展开更多
A series of multi-component M1-based hydrogen storage alloys witha cobalt atomic ratio of 0.40-0.75 were prepared. The electrochemicalproperties under different charge-discharge conditions and PCTcharaceristics measur...A series of multi-component M1-based hydrogen storage alloys witha cobalt atomic ratio of 0.40-0.75 were prepared. The electrochemicalproperties under different charge-discharge conditions and PCTcharaceristics measured by electrochemical method were investigated.The addition of other alloying elements for partial substitution ofCo low- ers the hydrogen equilibrium pressure and discharge capacity,but improves the cycling stability and makes the alloys keep nearlythe same rate discharge capability and high-temperature dischargecapability as those of the compared alloy. The reasons werediscussed.展开更多
The electrochemical characteristics and crystal structure of metal hydride electrode of AB_(3.5)-type alloy was studied. The electrochemical properties of the metal hydride electrode were investigated at room temperat...The electrochemical characteristics and crystal structure of metal hydride electrode of AB_(3.5)-type alloy was studied. The electrochemical properties of the metal hydride electrode were investigated at room temperature and -30 ℃. The partial substitution of Ni by Al element causes an expansion of the lattice cell and increases the specific capacity and rate discharge ability of the alloy.展开更多
Ti0.5Al0.25Ni0.25 alloy prepared by vacuum induction melting was studied.The phase composition was analyzed with X-ray technique and EDS analysis,and its electrochemical properties were investigated at various tempera...Ti0.5Al0.25Ni0.25 alloy prepared by vacuum induction melting was studied.The phase composition was analyzed with X-ray technique and EDS analysis,and its electrochemical properties were investigated at various temperatures.Electrochemical reaction kinetic parameters were also studied with proper electrochemical techniques.The influence of the secondary corrosion reaction on the anodic linear polarization measurement was also analyzed by theoretical simulation.The results show that,proper ball-milling with nickel powders is beneficial to electrochemical performance.The theoretical simulation proves that,the existence of the side reaction can disturb the measurement of electrochemical reaction kinetic parameters.展开更多
The electrochemical properties of RE(NiCoMnTi) 5 hydrogen storage alloy with different composition of rare earth(RE=La 1-x-y-z Ce x Nd y Pr z ) components were systematically examined To display...The electrochemical properties of RE(NiCoMnTi) 5 hydrogen storage alloy with different composition of rare earth(RE=La 1-x-y-z Ce x Nd y Pr z ) components were systematically examined To display the effect of rare earth elements on the electrode properties, the comprehensive electrochemical property graphs including the discharge capacity, high dischargeability and cycling life of alloy electrode vs quasi ternary rare earth composition of multicomponent alloys were drawn by first dividing the component elements into two groups with fixed ratios between the two groups and then using a computer program for engineering graphics By the optimizaiton of the La∶Ce∶Nd∶Pr ratio, the alloy RE(NiCoMnTi) 5 shows a maximum capacity of 290 mAh/g and good cycling stability The higher capacity was due to the larger unit cell volume of the alloy with RE=La 0 4 Ce 0 1 Nd 0 3 Pr 0 2 , as determined by X ray diffraction analysis展开更多
The effects of small amounts of added elements such as aluminum, titanium and zirconium to MlNi 3.8(CoMn) 1.2 on its electrochemical performances and performances at high temperatures were investigated.It is fou...The effects of small amounts of added elements such as aluminum, titanium and zirconium to MlNi 3.8(CoMn) 1.2 on its electrochemical performances and performances at high temperatures were investigated.It is found that the addition of aluminum brings about a significant increase in the discharge capacity at high temperatures,and the capacity decay during repeated charge-discharge cycles and the self-discharge are both suppressed, while the rate capability decreases.The alloy containing zirconium exhibits a longer cycle life and a better rate capability,but a much lower discharge capacity.The addition of titanium improves the rate capability, but the capacity decreases greatly.An X-ray diffraction analysis indicates that a second phase exists in the alloy with additive Zr or Ti,which improves the discharge-rate characteristics,and the superior stability of the alloy with additive Al may be due to the expansion of lattice parameters and cell volume.展开更多
Composite LaNi5+x wt.% Ti0.10Zr0.16V0.34Cr0.10Ni0.30 (x=0, 1, 5, 10) alloys were prepared by two-step re-melting. X-ray diffractometer (XRD), scanning electron microscopy (FESEM), energy dispersive spectrometry (EDS),...Composite LaNi5+x wt.% Ti0.10Zr0.16V0.34Cr0.10Ni0.30 (x=0, 1, 5, 10) alloys were prepared by two-step re-melting. X-ray diffractometer (XRD), scanning electron microscopy (FESEM), energy dispersive spectrometry (EDS), inductively coupled plasma (ICP) and electrochemical impedance spectroscopy (EIS) analyses showed that the matrix phase of LaNi5 alloy with CaCu5 structure remained unchanged after additive alloy was added, the amount of the second phase increased with increasing x. The synergetic effect withi...展开更多
文摘The crystal structure, the phase composition and the electrochemical characteristics of Zr0.9Ti0.1(Ni1.1Mn0.7V0.2)x (x=0.90, 0.95, 1.00, 1.05) alloys were investigated by means of XRD, SEM, EDS and electrochemical measurements. It was shown that all alloys are multiphase with C15 Laves phase as a main phase along with C14 phase and some secondary phases. And the amounts of the C14 phase and secondary phases in the four alloys increases with decreasing x. The results indicated that the various stoichiometric ratios have great effects on the electrochemical characteristics such as the maximum discharge capacity, discharge rate capability and self-discharge properties etc. for Zr0.9Ti0.1(Ni1.1Mn0.7 V0.2)X (x=0.90, 0.95, 1.00, 1.05) alloys. The hyper-stoichiometric Zr0.9 Ti0.1(N1.1Mn0.7 V0.20)1.05 exhibits the maximum discharge capacity of 332mAh-g-1. The C14 phase and secondary phases seems to improve discharge rate capability of the alloys.
文摘The degradation mechanism of electrochemical performance of sealed type nickel/metal hydride batteries was investigated. The results indicate that the degradation behavior of Ni/MH battery is not only owing to the lack of electrolyte, but also the deterioration of the active materials on the positive and negative electrodes of Ni/MH batteries. Scanning electron micrographs (SEM), X ray diffraction (XRD) and laser granularity analyses are presented. The particle pulverization and oxidation during charge/discharge are identified as the main causes for deterioration of the negative and positive electrode in nickel/metal hydride batteries, as well as the cross section cracking of both anode and cathode.
文摘A series of multi-component M1-based hydrogen storage alloys witha cobalt atomic ratio of 0.40-0.75 were prepared. The electrochemicalproperties under different charge-discharge conditions and PCTcharaceristics measured by electrochemical method were investigated.The addition of other alloying elements for partial substitution ofCo low- ers the hydrogen equilibrium pressure and discharge capacity,but improves the cycling stability and makes the alloys keep nearlythe same rate discharge capability and high-temperature dischargecapability as those of the compared alloy. The reasons werediscussed.
文摘The electrochemical characteristics and crystal structure of metal hydride electrode of AB_(3.5)-type alloy was studied. The electrochemical properties of the metal hydride electrode were investigated at room temperature and -30 ℃. The partial substitution of Ni by Al element causes an expansion of the lattice cell and increases the specific capacity and rate discharge ability of the alloy.
文摘Ti0.5Al0.25Ni0.25 alloy prepared by vacuum induction melting was studied.The phase composition was analyzed with X-ray technique and EDS analysis,and its electrochemical properties were investigated at various temperatures.Electrochemical reaction kinetic parameters were also studied with proper electrochemical techniques.The influence of the secondary corrosion reaction on the anodic linear polarization measurement was also analyzed by theoretical simulation.The results show that,proper ball-milling with nickel powders is beneficial to electrochemical performance.The theoretical simulation proves that,the existence of the side reaction can disturb the measurement of electrochemical reaction kinetic parameters.
文摘The electrochemical properties of RE(NiCoMnTi) 5 hydrogen storage alloy with different composition of rare earth(RE=La 1-x-y-z Ce x Nd y Pr z ) components were systematically examined To display the effect of rare earth elements on the electrode properties, the comprehensive electrochemical property graphs including the discharge capacity, high dischargeability and cycling life of alloy electrode vs quasi ternary rare earth composition of multicomponent alloys were drawn by first dividing the component elements into two groups with fixed ratios between the two groups and then using a computer program for engineering graphics By the optimizaiton of the La∶Ce∶Nd∶Pr ratio, the alloy RE(NiCoMnTi) 5 shows a maximum capacity of 290 mAh/g and good cycling stability The higher capacity was due to the larger unit cell volume of the alloy with RE=La 0 4 Ce 0 1 Nd 0 3 Pr 0 2 , as determined by X ray diffraction analysis
基金TheprojectisfinanciallysupportedbytheScienceResearchFoundationofOrdnanceEngineeringCollege (No .yjjxm0 0 0 6 )
文摘The effects of small amounts of added elements such as aluminum, titanium and zirconium to MlNi 3.8(CoMn) 1.2 on its electrochemical performances and performances at high temperatures were investigated.It is found that the addition of aluminum brings about a significant increase in the discharge capacity at high temperatures,and the capacity decay during repeated charge-discharge cycles and the self-discharge are both suppressed, while the rate capability decreases.The alloy containing zirconium exhibits a longer cycle life and a better rate capability,but a much lower discharge capacity.The addition of titanium improves the rate capability, but the capacity decreases greatly.An X-ray diffraction analysis indicates that a second phase exists in the alloy with additive Zr or Ti,which improves the discharge-rate characteristics,and the superior stability of the alloy with additive Al may be due to the expansion of lattice parameters and cell volume.
基金Project supported by Foundation of State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (CAS)
文摘Composite LaNi5+x wt.% Ti0.10Zr0.16V0.34Cr0.10Ni0.30 (x=0, 1, 5, 10) alloys were prepared by two-step re-melting. X-ray diffractometer (XRD), scanning electron microscopy (FESEM), energy dispersive spectrometry (EDS), inductively coupled plasma (ICP) and electrochemical impedance spectroscopy (EIS) analyses showed that the matrix phase of LaNi5 alloy with CaCu5 structure remained unchanged after additive alloy was added, the amount of the second phase increased with increasing x. The synergetic effect withi...
