Abstract: A metal nitride is added as the conductivity-imparting component to a positive electrode for alkaline storage battery, which contains the active material comprising nickel hydroxide as the main component to provide alkaline storage batteries having the good cycle characteristics.

Abstract: In order to provide a positive electrode active material capable of producing an alkaline storage battery having a high discharge voltage and an excellent discharge characteristic and also provide a positive electrode and alkaline storage battery containing thereof, a positive electrode active material for an alkaline storage battery comprising a nickel hydroxide powder is used, in which the nickel hydroxide is a solid solution containing magnesium, the magnesium content in the nickel hydroxide is 2 to 7 mol % of all metallic elements contained in the nickel hydroxide, the tap density of the nickel hydroxide is 1.9 g/cm3 or more, the half-width of a peak attributed to (101) face near 2&thgr;=37 to 40° in a powder X-ray diffraction pattern of the nickel hydroxide by CuK&agr; radiation is 0.7 to 1.2° and the sulfate ion content in the nickel hydroxide is 0.5 wt % or less.

Abstract: A metal nitride is added as the conductivity-imparting component to a positive electrode for alkaline storage battery, which contains the active material comprising nickel hydroxide as the main component to provide alkaline storage batteries having the good cycle characteristics.

Abstract: A process for producing positive electrode active material includes feeding an aqueous nickel salt solution, aqueous solutions of different kinds of metals, aqueous solution containing ammonium ions and aqueous alkali solution each independently and simultaneously into a reaction vessel such that the amount of alkali metal is 1.9-2.3 moles relative to 1 mole of the total amount of nickel and different kinds of metals and the amount of ammonium ions is 2 moles or more relative to 1 mole of the total amount of nickel and different kinds of metals, the pH in the vessel is 11-13, the temperature in the vessel is 30-60° C. and the average residence time is 20-50 hours.

Abstract: Disclosed is a high capacity positive active material for an alkaline storage battery comprising a nickel based multi-metals oxide, wherein the charge characteristic at high temperature is improved. This oxide has a large number of micropores in at least a surface layer. An average composition of the surface layer is different from that of the interior in that at least one element selected from the group consisting of Ca, Ti, Zn, Sr, Ba, Y, Cd, Co, Cr, Bi and lanthanoids, in addition to Ni, is contained in the surface layer, or in that the at least one element is contained at a concentration higher than that of the interior.

Abstract: The present invention discloses a cathode active material for an alkaline storage battery, which has a high energy density and a high cycle stability. The cathode active material includes particles of a solid solution or eutectic mixture nickel oxide, which has a crystal structure of &bgr;-Ni(OH)2 and contains at least Mn, where Mn has a mean valence of not less than 3.3, and a coating layer of a solid solution or eutectic mixture cobalt oxide formed on the surface of the particles, which contains at least one element of Ni and Mn.

Abstract: A positive electrode active material, includes a .beta.-Ni(OH).sub.2 type nickel oxide (including hydroxide) containing Mn in the state of solid solution or coprecipitated state with an average valence of Mn being 3.3 valences or more and preferably with a ratio A2/A1 being 1.25 or less which is a ratio of integrated intensity A2 of a peak present at 2.theta.=18-21.degree. to integrated intensity A1 of a peak present at 2.theta.=37-40.degree. of powder X-ray diffraction using CuK.alpha. ray.

Abstract: The energy density of active materials for a positive electrode comprising an oxide containing Ni as a main metallic element is enhanced, and, moreover, a method for manufacturing them is provided. The oxide includes Ni as a main metallic element and contains at least Mn in the state of solid solution or eutectic mixture, wherein the average valence of Mn is 3.3 valences or more, the tap density is 1.7 g/cc or more, the half width of a peak at around 2.theta.=37-40.degree. of X-ray diffraction using CuK.alpha. ray is 1.2 deg or less, the ratio B/A of integrated intensity B of a peak at around 2.theta.=18-21.degree. to integrated intensity A of a peak at around 2.theta.=37-40.degree. is 1.25 or less, and the volume of pores having a pore radius of 40 .ANG. or less is 60% or more of the total pore volume. The oxide is obtained by growing in the state of keeping the dissolved oxygen concentration in the aqueous solution in the reaction vessel and then oxidizing the oxide.

Abstract: A process for producing positive electrode active material includes feeding an aqueous nickel salt solution, aqueous solutions of different kinds of metals, aqueous solution containing ammonium ions and aqueous alkali solution each independently and simultaneously into a reaction vessel such that the amount of alkali metal is 1.9-2.3 moles relative to 1 mole of the total amount of nickel and different kinds of metals and the amount of ammonium ions is 2 moles or more relative to 1 mole of the total amount of nickel and different kinds of metals, the pH in the vessel is 11-13, the temperature in the vessel is 30-60.degree. C. and the average residence time is 20-50 hours.

Abstract: Active materials for positive electrodes in alkaline storage batteries excellent in capacity density, discharge voltage, and high rate discharge characteristics can be provided by coating the surface of the active material powder with an .alpha.-like Al-substituted Ni(OH).sub.2. Moreover, active materials excellent in capacity density, discharge voltage and high rate discharge characteristics, and besides in high-temperature charging efficiency and/or charge and discharge characteristics can be provided by dissolving in solid state and/or coprecipitated state at least one different metal element selected from Ca, Cr, Y, Ti and Co in the .alpha.-like Al-substituted Ni(OH).sub.2 layer. Furthermore, active materials excellent in capacity density, discharge voltage and high rate discharge characteristics, and besides in charge and discharge characteristics can be provided by coating with a Co oxide the surface of the active material powder coated with the .alpha.-like Al-substituted Ni(OH).sub.2.

Abstract: Disclosed is a sealed alkaline storage battery with an increased utilization of a positive electrode active material comprising a nickel oxide and with drastically enhanced capacity density. The positive electrode active material is a nickel based multi-metals oxide containing at least one element such as Mn which promotes the formation of .gamma. phase during charging. The ratio A.sub..gamma. /A.sub..beta. of the integrated intensity A.sub..gamma. of the diffraction peak at d=about 7 angstroms attributed to the .gamma. phase to the integrated intensity A.sub..gamma. of the diffraction peak at d=about 4.5 to 5.0 angstroms attributed to the .beta. phase of the oxide in the completely charged state is not smaller than 0.4. The electrolyte comprises an aqueous solution containing at least one of K.sup.+ and Na.sup.+ as a cationic component and the total concentration of the above-mentioned cationic component in the completely charged state is within a range between 4 and 12 mol/l.