NOVELTY - An alkaline rechargeable battery (2) comprises an electrode assembly (22) and an alkaline electrolyte enclosed in a hermetically-sealed container, where the electrode assembly is formed of a positive electrode (24) and negative electrode (26) stacked with a separator (28) interposed between it, the positive electrode holds a positive electrode mixture containing positive-electrode active material particles formed primarily of nickel hydroxide, and a positive-electrode additive distributed between the positive-electrode active material particles.    USE - As an alkaline rechargeable battery (claimed), used in portable devices and hybrid electric vehicles.    ADVANTAGE - In the alkaline rechargeable battery, aluminum or an aluminum compound added as a positive-electrode additive that reduces self-discharge of the battery. The lithium present within the battery reduces the amount of gamma -nickel oxide hydroxide ( gamma -NiOOH) produced by adding aluminum or an aluminum compound thus increases the positive-electrode active material utilization ratio. The alkaline rechargeable battery exhibits both reduced self-discharge and increased positive-electrode active material utilization ratio.    DETAILED DESCRIPTION - An alkaline rechargeable battery (2) comprises an electrode assembly (22) and an alkaline electrolyte enclosed in a hermetically-sealed container, where the electrode assembly is formed of a positive electrode (24) and a negative electrode (26) stacked with a separator (28) interposed between it, the positive electrode holds a positive electrode mixture containing positive-electrode active material particles formed primarily of nickel hydroxide, and a positive-electrode additive distributed between the positive-electrode active material particles, the positive-electrode additive is at least one substance selected from aluminum and aluminum compounds, where the amount uranium (U) of the positive-electrode additive (in parts by weight) relative to 100 parts by weight of the positive-electrode active material particles is 0.01-1.5, and lithium (Li) is present within the alkaline rechargeable battery, where the total amount of Li present within the alkaline rechargeable battery, in terms of weight of lithium hydroxide (LiOH) per unit positive-electrode capacitance 1Ah, is 20-30 mg/Ah.    DESCRIPTION OF DRAWING(S) - The figure shows a partially-cutaway perspective view of a nickel-metal hydride rechargeable battery.    Alkaline rechargeable battery (2)    Electrode assembly (22)    Positive electrode (24)    Negative electrode (26)    Separator (28)    Positive-electrode active material particle (36)    Hydrogen-absorbing alloy particle (44)