As the loss of active material Mg may affect electrode’s discharge capacity and the cycling stability, a more refined mechanism study on cycling capacity degradation should be made. The present investigation is based...As the loss of active material Mg may affect electrode’s discharge capacity and the cycling stability, a more refined mechanism study on cycling capacity degradation should be made. The present investigation is based on the supposition that the capacity degradation of the binary Mg50Ni50 alloy and ternary Mg45Cu5Ni50 alloy electrodes is solely due to the corrosion of Mg, the active hydrogen storage element. That means amount of capacity degradation is determined by the corrosion current time, which is also the time of operation. The corrosion current J corr dependence on cycling time was deduced. A mathematic relation between the cycling capacity retention C N / C 1 (%) and the duration of operation was also deduced. The data calculated from the equations deduced agree well with those of the experiment result. The loss of the active hydrogen absorbing element Mg is proved to be the main cause for cycling capacity deterioration in the present investigation.展开更多
The Mg0.9Ti0.1Ni1?xPdx (x= 0, 0.05, 0.1, 0.15) hydrogen storage electrode alloys were prepared by mechanical alloying. The main phases of the alloys were determined as amorphous by X-ray diffraction(XRD). The corrosio...The Mg0.9Ti0.1Ni1?xPdx (x= 0, 0.05, 0.1, 0.15) hydrogen storage electrode alloys were prepared by mechanical alloying. The main phases of the alloys were determined as amorphous by X-ray diffraction(XRD). The corrosion potentials of the alloys were measured by open circuit potential measurements and the values are ?0.478, ?0.473, ?0.473 and ?0.471 V (vs Hg/HgO electrode) for x=0, 0.05, 0.1, 0.15, respectively. The corrosion currents of the studied alloys were obtained by non-linear fitting of the anodic polarization curve using Bulter-Volmer equation and Levenberg-Marquardt algorithm, which were obtained after different cycles. The initial corrosion currents of the alloys are decreased with the increasing of Pd content. The increasing of Pd content in the alloys inhibits the corrosion rates of the electrode alloys with the progress of cycle number. The electrochemical impedance spectroscopy(EIS) was conducted after open circuit potential of the alloys stabilizing. The impedance data fit well with the theoretical values obtained by the proposed equivalent circuit model. The corrosion resistances and the thickness of surface passive film of the alloys, which were deduced by the analyses of EIS, are enhanced with the increasing of Pd content in the alloys, which are consistent with the results of corrosion rates obtained from anodic polarization measurements.展开更多
文摘As the loss of active material Mg may affect electrode’s discharge capacity and the cycling stability, a more refined mechanism study on cycling capacity degradation should be made. The present investigation is based on the supposition that the capacity degradation of the binary Mg50Ni50 alloy and ternary Mg45Cu5Ni50 alloy electrodes is solely due to the corrosion of Mg, the active hydrogen storage element. That means amount of capacity degradation is determined by the corrosion current time, which is also the time of operation. The corrosion current J corr dependence on cycling time was deduced. A mathematic relation between the cycling capacity retention C N / C 1 (%) and the duration of operation was also deduced. The data calculated from the equations deduced agree well with those of the experiment result. The loss of the active hydrogen absorbing element Mg is proved to be the main cause for cycling capacity deterioration in the present investigation.
基金Project(20473091) supported by the National Natural Science Foundation of China
文摘The Mg0.9Ti0.1Ni1?xPdx (x= 0, 0.05, 0.1, 0.15) hydrogen storage electrode alloys were prepared by mechanical alloying. The main phases of the alloys were determined as amorphous by X-ray diffraction(XRD). The corrosion potentials of the alloys were measured by open circuit potential measurements and the values are ?0.478, ?0.473, ?0.473 and ?0.471 V (vs Hg/HgO electrode) for x=0, 0.05, 0.1, 0.15, respectively. The corrosion currents of the studied alloys were obtained by non-linear fitting of the anodic polarization curve using Bulter-Volmer equation and Levenberg-Marquardt algorithm, which were obtained after different cycles. The initial corrosion currents of the alloys are decreased with the increasing of Pd content. The increasing of Pd content in the alloys inhibits the corrosion rates of the electrode alloys with the progress of cycle number. The electrochemical impedance spectroscopy(EIS) was conducted after open circuit potential of the alloys stabilizing. The impedance data fit well with the theoretical values obtained by the proposed equivalent circuit model. The corrosion resistances and the thickness of surface passive film of the alloys, which were deduced by the analyses of EIS, are enhanced with the increasing of Pd content in the alloys, which are consistent with the results of corrosion rates obtained from anodic polarization measurements.
