Effect of electron irradiation on the property of electrochemical hydrogen absorption by a Mm-Ni based alloy

Muraki, Keita*; Nakagawa, Takuya*; Kishimoto, Masahiko*; Abe, Hiroshi; Hiraki, Takeshi*; Uchida, Hirohisa*

In this study, we examined the effect of electron irradiation on the surface of a hydrogen storage alloy in order to improve the initial activation. We measured the initial rate of hydrogen absorption in an electrochemical process, and found that the electron irradiation treatment in the atmosphere is more effective than that in the vacuum or helium gas. Based on results of surface analysis of the alloy by ESCA, we found the existence of non-stoichiometric oxides of rare earths. As well known, non-stoichiometric rare earth oxides such as CeO and LaO has a high ability to dissociate covalent molecules like HO. This paper demonstrates an effective surface treatment of electron irradiation, and the important catalytic actions of rare earth oxides in the surface to improve the initial activation of the alloy.