Abstract: A sintered substrate is configured such that pores having a pore size (pore radius) of from 5 ?m to 7 ?m have a peak volume fraction with respect to the total pore volume of the sintered substrate, and pores having a pore radius of greater than 8.5 ?m has a volume fraction of 11% or less with respect to the total pore volume of the sintered substrate. The sintered substrate has a smaller number of large-sized pores than conventional sintered substrates and a more uniform pore size distribution, and therefore shows a sufficient strength even when the porosity is increased. In addition, a cadmium negative electrode employing the sintered substrate shows excellent gas absorption capability and therefore can reduce the internal pressure of the battery during charge.

Abstract: A sintered substrate is configured such that pores having a pore size (pore radius) of from 5 ?m to 7 ?m have a peak volume fraction with respect to the total pore volume of the sintered substrate, and pores having a pore radius of greater than 8.5 ?m has a volume fraction of 11% or less with respect to the total pore volume of the sintered substrate. The sintered substrate has a smaller number of large-sized pores than conventional sintered substrates and a more uniform pore size distribution, and therefore shows a sufficient strength even when the porosity is increased. In addition, a cadmium negative electrode employing the sintered substrate shows excellent gas absorption capability and therefore can reduce the internal pressure of the battery during charge.

Abstract: An electrode assembly of an alkaline secondary battery includes positive and negative electrodes disposed to face each other via a separator sandwiched therebetween. The separator has a dual-layer structure composed of a main-fiber nonwoven layer and an aromatic-polyamide-fiber nonwoven layer that are laminated in the thickness direction. The main-fiber nonwoven layer contains nylon as main fiber and does not contain aromatic-polyamide-fiber. In the electrode assembly, the separator is so disposed that the aromatic-polyamide-fiber nonwoven fabric layer faces toward the negative electrode.

Abstract: A nickel electrode for an alkaline storage battery is made by filling a conductive porous member with an active material including a main active material layer substantially made of nickel hydroxide and containing cobalt in a state of a solid solution, and a compound layer containing at least one element selected from the group consisting of calcium, aluminum, strontium, scandium, yttrium, and lanthanoide series, the compound layer being formed on a surface of the main active material layer. A metal molar ratio of cobalt contained in the main active material layer to nickel contained in the main active material layer is in a range of 0.5% to 3.0%, and a metal molar ratio of the at least one element contained in the compound layer to nickel contained in the active material is in a range of 0.3% to 5.0%.

Abstract: A method of producing a nickel electrode for an alkaline storage battery, comprising: an active-material loading step comprising preparing an active-material loaded plate electrode by loading an active-material containing nickel hydroxide as its principal component into the pores of said porous electrically conductive substrate; an immersion step comprising immersing said active-material loaded plate electrode into an impregnation solution comprising an acid salt solution containing at least one element selected from the group consisting of Ca, Sr, Sc, Y, Al, Mn, and lanthanides; and an alkali treatment step comprising forming a hydroxide layer on the surface of the electrode plate by converting the acid salt into a hydroxide by immersing said plate electrode into an alkaline solution; provided that the temperature of the impregnation solution is controlled in a range of from 40 to 90° C., and that the pH value of impregnating solution is controlled to a range of from 4 to 6.

Abstract: A nickel electrode for alkaline storage battery of the invention comprises an electrically-conductive porous substrate coated with an oxide containing cobalt on the surface thereof and a positive active material coated with nickel and a compound selected from the group consisting of Ca, Sr, Sc, Y, Al, Mn and lanthanoids on the surface thereof. Thus, the coating of the surface of the active material with nickel and a compound containing Ca, Sr, Sc, Y, Al, Mn and lanthanoids causes the enhancement of the effect of increasing oxygen overvoltage at high temperature and hence the charge acceptability. Further, since the gap between the electrically-conductive porous substrate and the positive active material is filled with the oxide containing cobalt, the electrical conductivity thereof can be improved, making it possible to inhibit the deterioration of large current charge properties and large current discharge properties.

Abstract: A method of producing a nickel electrode for an alkaline storage battery, comprising: an active-material loading step comprising preparing an active-material loaded plate electrode by loading an active-material containing nickel hydroxide as its principal component into the pores of said porous electrically conductive substrate; an immersion step comprising immersing said active-material loaded plate electrode into an impregnation solution comprising an acid salt solution containing at least one element selected from the group consisting of Ca, Sr, Sc, Y, Al, Mn, and lanthanides; and an alkali treatment step comprising forming a hydroxide layer on the surface of the electrode plate by converting the acid salt into a hydroxide by immersing said plate electrode into an alkaline solution; provided that the temperature of the impregnation solution is controlled in a range of from 40 to 90° C., and that the pH value of impregnating solution is controlled to a range of from 4 to 6.

Abstract: A nickel electrode for an alkaline storage battery is made by filling a conductive porous member with an active material including a main active material layer substantially made of nickel hydroxide and containing cobalt in a state of a solid solution, and a compound layer containing at least one element selected from the group consisting of calcium, aluminum, strontium, scandium, yttrium, and lanthanoide series, the compound layer being formed on a surface of the main active material layer. A metal molar ratio of cobalt contained in the main active material layer to nickel contained in the main active material layer is in a range of 0.5% to 3.0%, and a metal molar ratio of the at least one element contained in the compound layer to nickel contained in the active material is in a range of 0.3% to 5.0%.