Abstract: A sealed type nickel-hydride battery comprising a positive electrode made of nickel oxides and/or Ni(OH).sub.2 as an active material, a negative electrode made of hydrogen storage alloys as main materials which may absorb and desorb hydrogen as an active material electrochemically, an alkaline electrolyte, and a separator. Prior to sealing in a battery case, the positive electrode contains cobalt and/or cobalt hydroxide having an oxidation potential lower than that of nickel hydroxide and the negative electrode is not subjected to a sufficient precharge as required for the substantial battery capacity to be limited by the capacity of the positive electrode. The battery is sealed in this state, and at an initial charge, the cobalt and/or cobalt oxides are charged and a precharged section absorbed hydrogen is formed in a negative electrode corresponding to the charge capacity of the cobalt and/or cobalt oxides.

Abstract: Disclosed is an improvement of a hydrogen absorbing alloy to be used as a negative electrode of an alkaline storage battery. The hydrogen absorbing alloy capable of electrochemically absorbing/desorbing hydrogen has a CaCu.sub.5 type crystal structure and is represented by the general formula of A.sub.1-x B.sub.x C.sub.y D.sub.z, in which formula: D is selected from the group consisting of V, In, Tl, Ga and mixtures thereof; the atomic ratio z has a value within the range made up as follows, 0.02.ltoreq.z.ltoreq.0.3 for V, 0.02.ltoreq.z.ltoreq.0.1 for In, 0.02.ltoreq.z.ltoreq.0.1 for Tl, and 0.02.ltoreq.z.ltoreq.0.1 for Ga; and the atomic ratio (y+z) has a value within the range of from 4.7 to 5.3.

Abstract: A sealed storage battery comprises a positive electrode including a metallic oxide as an active material, a negative electrode including hydrogen-storage-alloy powder capable of electrochemically charging and discharging hydrogen as an active material, an alkaline electrolyte, and two separators (12a and 1 2b) for absorbing and retaining the alkaline electrolyte. The hydrogen-storage-alloy power has a crystal structure and is provided with numerous irregularities on the surface thereof, and has SF-value of 2.5 or below, which SF-value represents a plateau characteristic of equilibrium pressure of released hydrogen. The numerous irregularities on the surface of the alloy powder cause oxygen being generated from the positive electrode to be eliminated promptly.