Fuel cell using borohydride as the fuel has received much attention. AB5-type hydrogen storage alloy used as the anodic material instead of noble metals has been investigated. In order to restrain the generation of hy...Fuel cell using borohydride as the fuel has received much attention. AB5-type hydrogen storage alloy used as the anodic material instead of noble metals has been investigated. In order to restrain the generation of hydrogen and enhance the utilization of borohydride, Ti/Zr metal powders has been added into the parent LmNi4.78Mn0.22 （where Lm is La-richened mischmetal） alloy （LNM） by ball milling and heat treatment methods. It is found that the addition of Ti/Zr metal powders lowers the electrochemical catalytic activity of the electrodes, at the same time, restrains the generation of hydrogen and enhances the utilization of the fuel. All the results show that the hydrogen generation rate or the utilization of the fuel is directly relative to the electrochemical catalytic activity or the discharge capability of the electrodes. The utilization of the fuel increases with discharge current density. It is very important to find a balance between the discharge capability and the utilization of the fuel.展开更多
Low-temperature performance and high-rate discharge capability of AB5-type non-stoichiometric hydrogen storage are studied. X-ray diffraction(XRD),pressure-composition-temperature(PCT) curves and electrochemical imped...Low-temperature performance and high-rate discharge capability of AB5-type non-stoichiometric hydrogen storage are studied. X-ray diffraction(XRD),pressure-composition-temperature(PCT) curves and electrochemical impedance spectroscopy(EIS) are applied to characterize the electrochemical properties of ABx(x=4.8,4.9,5.0,5.1,5.2) alloys. The results show that the non-stoichiometric alloys exhibit better electrochemical properties compared with that of the AB5 alloy.展开更多
Perovskite-type SrTiO3 powders were prepared by using strontium acetate, tetrabutyl titanate and sodium hydroxide via direct hydrolysis-precipitation process. AB5-type hydrogen storage alloy（HSA） electrodes modified...Perovskite-type SrTiO3 powders were prepared by using strontium acetate, tetrabutyl titanate and sodium hydroxide via direct hydrolysis-precipitation process. AB5-type hydrogen storage alloy（HSA） electrodes modified with SrTiO3 powders were prepared and the photoelectrochemical characteristics of the as-prepared electrodes were investigated. The results of cyclic voltammograph show that the current of reduction peak increases remarkably under the light irradiation. The obvious photochargeable properties are obtained for the hydrogen storage alloys modified with Perovskite-type SrTiO3 powders. During photocharging process, the potential of the electrode shifts quickly to negative direction and a potential plateau occurs. HSA electrode modified with SrTiO3 powders prepared by direct hydrolysis-precipitation process gives the higher potential of about -0.90V（vs Hg/HgO） under the light irradiation. SEM observation discloses that a large amount of microcracks occur on the surface of the electrode after photocharging process, which is caused by the formation of hydride in the bulk of electrode.展开更多
文摘Fuel cell using borohydride as the fuel has received much attention. AB5-type hydrogen storage alloy used as the anodic material instead of noble metals has been investigated. In order to restrain the generation of hydrogen and enhance the utilization of borohydride, Ti/Zr metal powders has been added into the parent LmNi4.78Mn0.22 （where Lm is La-richened mischmetal） alloy （LNM） by ball milling and heat treatment methods. It is found that the addition of Ti/Zr metal powders lowers the electrochemical catalytic activity of the electrodes, at the same time, restrains the generation of hydrogen and enhances the utilization of the fuel. All the results show that the hydrogen generation rate or the utilization of the fuel is directly relative to the electrochemical catalytic activity or the discharge capability of the electrodes. The utilization of the fuel increases with discharge current density. It is very important to find a balance between the discharge capability and the utilization of the fuel.
基金Project(2006AA11A151) supported by the National Hi-Tech Research and Development Program of China
文摘Low-temperature performance and high-rate discharge capability of AB5-type non-stoichiometric hydrogen storage are studied. X-ray diffraction(XRD),pressure-composition-temperature(PCT) curves and electrochemical impedance spectroscopy(EIS) are applied to characterize the electrochemical properties of ABx(x=4.8,4.9,5.0,5.1,5.2) alloys. The results show that the non-stoichiometric alloys exhibit better electrochemical properties compared with that of the AB5 alloy.
基金Project(50201016) supported by the National Natural Science Foundation of China Project(Y404044) supported by theNatural Science Foundation of Zhejiang Province
文摘Perovskite-type SrTiO3 powders were prepared by using strontium acetate, tetrabutyl titanate and sodium hydroxide via direct hydrolysis-precipitation process. AB5-type hydrogen storage alloy（HSA） electrodes modified with SrTiO3 powders were prepared and the photoelectrochemical characteristics of the as-prepared electrodes were investigated. The results of cyclic voltammograph show that the current of reduction peak increases remarkably under the light irradiation. The obvious photochargeable properties are obtained for the hydrogen storage alloys modified with Perovskite-type SrTiO3 powders. During photocharging process, the potential of the electrode shifts quickly to negative direction and a potential plateau occurs. HSA electrode modified with SrTiO3 powders prepared by direct hydrolysis-precipitation process gives the higher potential of about -0.90V（vs Hg/HgO） under the light irradiation. SEM observation discloses that a large amount of microcracks occur on the surface of the electrode after photocharging process, which is caused by the formation of hydride in the bulk of electrode.
