Abstract: The present invention relates to a fuel cell comprising an aqueous alkaline solution of electrolyte containing a hydrogen-releasing agent selected from the group consisting of NaBH4, KBH4, LiAlH4, KH and NaH, an oxygen electrode as a cathode and a hydrogen storage alloy electrode as an anode.

Abstract: A zirconium-based hydrogen storage alloys having the composition formula:Zr.sub.1-x Q.sub.x Cr.sub.1-Y-Z-A-B Mn.sub.Y Fe.sub.Z Co.sub.A V.sub.B Ni(I)wherein Q is Ti or Hf; 0<x.ltoreq.0.3; and 0<Y+Z+A+B<1, are disclosed. The Zr-based hydrogen storage alloy has a C-14 hexagonal structure and is mainly composed of single phase. The alloy is useable for a negative electrode material for secondary batteries. The Zr-based hydrogen storage alloy also has also a discharge capacity of 300.about.377 mAg/g and low reduction of discharge capacity at a low temperature and discharge rate.

Abstract: The specification describes novel zirconium-based hydrogen storage materials useful as negative electrodes for rechargeable batteries. The materials according to the present invention are represented by the following empirical formula:Zr-based metal hydrides+Mx (I)wherein M is a light rare earth metal selected from the group consisting of La, Nd, and Mm; 0<x<0.1; and the Zr-base metal hydrides means mainly that the metal hydrides are mainly in Zr-based Laves phase such as ZrCrNi, Zr (V.sub.0.33 Ni.sub.0.67).sub.2.4. Another group of the materials is represented by the following formula:ZrCr.sub.1+y Ni.sub.1+z (II)wherein, 0.ltoreq.y.ltoreq.0.2, and 0.ltoreq.z.ltoreq.0.2, provided that y and z cannot denote 0 concurrently. The negative electrodes made of these alloys need only a small number of activation cycles and thus, exhibit an improved activation behavior without any pretreatments for the activation.