Abstract: The negative electrode of this invention includes, as a negative electrode active material, substantially amorphous aluminum alloy in the form of a powder with an average particle size of 50 &mgr;m or less represented by a composition formula, Al100-xMx, in which M is at least one element selected from the group consisting of La, Y, Yb, Ce, Gd, Nd, Sm, Pr, Er, Ni, Co, Cu and Fe; and 1≦x≦20. Owing to this negative electrode, a lithium secondary battery having large discharge capacity and exhibiting very good charge-discharge cycle performance can be realized.

Abstract: A sealed alkaline-zinc storage battery includes a battery can, a hollow positive electrode disposed within the battery can in electrical contact therewith and containing a positive active material including nickle hydroxide, a negative electrode disposed inwardly of the positive electrode and containing a negative active material including zinc, a separator disposed between the positive and negative electrodes, a negative current collector inserted into the negative electrode, and an alkaline electrolyte filled in the battery can and impregnated into the positive electrode, negative electrode and separator. The positive electrode, negative electrode, separator, negative current collector and electrolyte together account for at least 75% of an internal volume of the battery can. The alkaline electrolyte is in the 30 to 45 mass % concentration range and has a total water content in the range of 0.5 to 0.9 g for each theoretical capacity of the negative electrode expressed as 1 Ah (ampere-hour).

Abstract: A sealed alkaline storage battery using, as a positive electrode active material, nickel oxyhydroxide including Mn as a solid-solution element and having a &ggr; ratio of 65 through 100%; a sealed alkaline storage battery using, as a positive electrode active material, nickel oxyhydroxide including as an additive or coated with a rare earth element and/or a rare earth compound in a ratio measured based on the rare earth element of 0.05 through 5 wt %; and a sealed alkaline storage battery including, as a positive electrode active material, nickel oxyhydroxide having a half-width of a peak in a lattice plane (003) in an X-ray diffraction pattern of 0.8° or more. The pressure within the battery is not largely increased for a long period of charge-discharge cycles, and hence, the electrolyte hardly leaks.

Abstract: The present invention is directed to an alkaline secondary battery comprising a positive electrode, a zinc based negative electrode, and an alkaline electrolyte solution, wherein the positive electrode includes a central cavity for receiving the zinc based negative electrode, and the negative electrode includes a central cavity for holding the alkaline electrolyte solution. The battery is arranged such that the positive electrode presents a smaller capacity than the negative electrode at least in an initial charge/discharge period.

Abstract: The invention provides a sealed alkaline-zinc storage battery including a tubular positive electrode containing, as an active material, a material having reversibility in a charge-discharge reaction; a separator; a negative electrode disposed within the tubular positive electrode with the separator sandwiched therebetween; and an alkaline electrolyte, in which the positive electrode has a capacity smaller than a capacity of the negative electrode at least in initial charge-discharge cycles, and the amounts of an uncharged active material and zinc to be packed in the negative electrode in manufacture of the sealed alkaline-zinc storage battery are set so that a theoretical capacity P of the uncharged active material existing in the negative electrode can be 0.3 through 1.8 times as large as a battery capacity in a completely charged state in the initial charge-discharge cycles, and that a theoretical capacity Q of zinc existing in the negative electrode can be 0.6 through 2.

Abstract: A positive-electrode active material for alkaline secondary battery according to the invention has an &agr;-Ni(OH)2 crystal structure which incorporates therein manganese and a trivalent metal other than manganese.

Abstract: In an alkali storage battery comprising a positive electrode, a negative electrode and an alkali electrolyte in a battery can, .alpha.-nickel hydroxide containing manganese is used as a cathode active material for the positive electrode, and the difference between a charging potential and an oxygen gas evolution potential at the positive electrode is increased, to suppress oxygen gas evolution during the charging, and the volume percentage of the cathode active material and an anode active material is set to not less than 75% in the battery can, to obtain a large battery capacity.

Abstract: Non-sintered nickel electrodes for alkaline storage batteries which can express high active material utilization efficiency not only at the time of charging at ordinary temperature but also at the time of charging in a high-temperature atmosphere are provided by using an active material powder composed of composite particles each comprising a substrate particle containing nickel hydroxide, an inner coat layer covering the substrate particle and comprising yttrium, scandium or a lanthanoid, or an yttrium, scandium or lanthanoid compound, and an outer coat layer covering the inner coat layer and comprising cobalt or a cobalt compound, or composed of composite particles each comprising a substrate particle containing nickel hydroxide, an inner coat layer covering the substrate particle and comprising cobalt or a cobalt compound, and an outer coat layer covering the inner coat layer and comprising yttrium, scandium or a lanthanoid, or an yttrium, scandium or lanthanoid compound.

Abstract: A conductive agent for use in alkaline storage batteries in accordance with one aspect of the present invention contains 0.1 to 10% by weight sodium. This sodium content results from cobalt or a cobalt compound, to which an aqueous solution of sodium hydroxide is added and heated to 50 to 200.degree. C. A non-sintered nickel electrode for use in alkaline storage batteries is also proposed. In this electrode, the aforesaid conductive agent in accordance with the present invention is added to a pulverulent active material consisting of grains of nickel hydroxide or grains mainly constituted by nickel hydroxide such that 1 to 20 parts by weight of the conductive agent is added to 100 parts by weight nickel hydroxide contained in the pulverulent active material. Another non-sintered nickel electrode for use in alkaline storage batteries is also proposed.

Abstract: In the non-sintered nickel electrode for an alkaline storage battery according to the invention, a yttrium metal powder and/or a yttrium compound powder has been added to a particulate active material comprising composite particles each consisting of a nickel hydroxide core and a sodium-doped cobalt compound shell. Because the yttrium metal powder and/or yttrium compound powder inhibits the diffusion of cobalt into the nickel hydroxide core, the non-sintered nickel electrode of the invention exhibits a high utilization efficiency not only in an initial phase of charge-discharge cycling but over a long time of use. Moreover, because the yttrium metal powder and/or yttrium compound powder enhances the oxygen overpotential, the non-sintered nickel electrode for an alkaline storage battery according to the invention shows very satisfactory charge characteristics particularly at high temperatures.

Abstract: An non-sintered nickel electrode of alkaline batteries uses an active material powder which comprises composite particles comprising nickel hydroxide particles or solid solution particles consisting essentially of nickel hydroxide the surface of which is covered with a mixed crystal of cobalt hydroxide and the hydroxide of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc. With this electrode, the cobalt hydroxide, which covers as a component of the mixed crystal the surface of the nickel hydroxide particles, minimally diffuses into them. Alkaline batteries using this electrode as positive electrode can therefore maintain, for a long period of time of charge-discharge cycles, the function of the cobalt hydroxide of increasing the conductivity of the electrode, thereby suppressing decrease in the discharge capacity in the course of charge-discharge cycles.

Abstract: A non-sintered nickel electrode for use in alkaline storage cells includes an active material comprising a solid solution of nickel hydroxide mixed with manganese, the solid solution further incorporating one or more elements selected from a group consisting of cobalt, cadmium, calcium and magnesium; an active material comprising a solid solution of nickel hydroxide mixed with manganese and zinc, the solid solution further incorporating one or more elements selected from a group consisting of cobalt, cadmium, calcium and magnesium; or an active material comprising nickel hydroxide with manganese added thereto, some of which manganese is incorporated in a solid solution of nickel hydroxide and the rest of which manganese exists as liberated from the solid solution of nickel hydroxide.

Abstract: An non-sintered nickel electrode of alkaline batteries uses an active material powder which comprises composite particles comprising nickel hydroxide particles or solid solution particles consisting essentially of nickel hydroxide the surface of which is covered with a mixed crystal of cobalt hydroxide and the hydroxide of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc. With this electrode, the cobalt hydroxide, which covers as a component of the mixed crystal the surface of the nickel hydroxide particles, minimally diffuses into them. Alkaline batteries using this electrode as positive electrode can therefore maintain, for a long period of time of charge-discharge cycles, the function of the cobalt hydroxide of increasing the conductivity of the electrode, thereby suppressing decrease in the discharge capacity in the course of charge-discharge cycles.

Abstract: Non-amalgamated zinc alloy powder is prepared by admixing zinc alloy powder with a predetermined amount of indium and heating the resulting mixture at temperature ranging from 160.degree. C. to 200.degree. C. in inert gas atmosphere.

Abstract: A zinc alkaline cell is formed by using an anode active material which contains a non-amalgamated zinc alloy powder having a bulk specific gravity ranging from approximately 2.90 to 3.50 (grams per cm.sup.3) and containing a predetermined amount of indium coated on a surface of the non-amalgamated zinc alloy powder containing a predetermined amount of aluminum and/or a predetermined amount of calcium as a zinc alloy powder component, other than unavoidable impurities. The zinc alkaline cell can achieve corrosive resistance and discharge performance as a cell and it is comparable with cells formed by using amalgamated zinc alloy powder which has been practically employed.

Abstract: A zinc alkaline cell is formed by using an anode active material which contains a non-amalgamated zinc alloy powder having a bulk specific gravity ranging from approximately 2.90 to 3.50 (grams per cm.sup.3) and containing a predetermined amount of indium coated on a surface of the non-amalgamated zinc alloy powder containing a predetermined amount of lead or a predetermined amount of a mixture of lead with bismuth or aluminum as a zinc alloy powder component, other than unavoidable impurities. The zinc alkaline cell can achieve corrosive resistance and discharge performance as a cell and it is comparable with cells formed by using amalgamated zinc alloy powder which has been practically employed.

Abstract: A zinc alkaline cell is formed by using an anode active material which contains a non-amalgamated zinc alloy powder having a bulk specific gravity ranging from approximately 2.90 to 3.50 (grams per cm.sup.3) and containing a predetermined amount of indium coated on a surface of the non-amalgamated zinc alloy powder containing a predetermined amount of lead and calcium or a predetermined amount of calcium and bismuth as a zinc alloy powder component, other than unavoidable impurities. The zinc alkali cell can achieve corrosive resistance and discharge performance as a cell and it is comparable with cells formed by using amalgamated zinc alloy powder which has been practically employed.