Effects of ion irradiation on hydriding rate of Mm based hydrogen storage alloy

Abe, Hiroshi; Morimoto, Ryo*; Sato, Fumiatsu*; Azuma, Yorito*; Uchida, Hirohisa*

Mm(misch metal) based hydrogen storage alloys are applied to the negative electrode of the Ni-H battery and other hydrogen storage systems. In such pratical applications, various surface processes of hydrogen molecules often become rate contolling. Therefore, the improvement of the alloy surface is of great importance to promote the initial activation and hydriding rate. We have reported that the alkaline pretreatment of an alloy surfece exhibits a high durability against CO attack. Since low energy ion irradiation is quite useful for surface modification of materials, the hydriding proerties of a Mm is expected on electrochemical hydriding rate of the alloy. As a result, the ion irradiation Mm was found to induce a higher hydriding rate than that of the un-irradiation one.