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AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsSusumu Kikuyama, Takashi Ebihara, Akiko Miyahara, Xianglong Wang, Kohji Yuasa
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An alkaline storage battery which is excellent in charge and discharge cycle life characteristics and high-rate discharge characteristics is provided by constructing it using an electrode made of an MmNi type hydrogen-absorbing alloy powders having modified surface. The alkaline storage battery comprises a negative electrode made using a hydrogen-absorbing alloy in the form of powders comprising at least one rare earth element, nickel and at least one transition metal in which the surface portion of the alloy has nickel in metallic state exposed at the surface, pores positioned between the nickel and the nickel, and a nickel-rich layer present on the alloy surface contacting with the pores, a positive electrode made using a metal oxide, a separator, and an alkaline electrolyte.
A hydrogen-absorbing alloy for batteries in the form of powders comprising at least one rare earth element, nickel and at least one transition metal in which the surface portion of the alloy has nickel in metallic state exposed at the surface, pores positioned between the nickel and the nickel, and a nickel-rich layer present on the alloy surface contacting with the pores.
A method for producing a hydrogen-absorbing alloy for batteries which comprises a first step of grinding a hydrogen-absorbing alloy comprising at least one rare earth element, nickel and at least one transition metal to prepare alloy powders, a second step of treating the alloy powders in an alkaline aqueous solution, a third step of treating the alloy powders in an acidic aqueous solution, and a fourth step of a dehydrogenation treatment to remove hydrogen absorbed in the alloy powders in the presence of acetate ion in an aqueous solution.
An alkaline storage battery which has a negative electrode comprising a hydrogen-absorbing alloy in the form of powders comprising at least one rare earth element, nickel and at least one transition metal in which the surface portion of the alloy has nickel in metallic state exposed at the surface, pores positioned between the nickel and the nickel, and a nickel-rich layer present on the alloy surface contacting with the pores;
A hydrogen-absorbing alloy for batteries in the form of powders comprising at least one rare earth element, nickel and at least one transition metal in which the surface portion of the alloy has nickel in metallic state exposed at the surface, pores positioned between the nickel and the nickel, and a nickel-rich layer present on the alloy surface contacting with the pores, the surface of the nickel in metallic state and the surface of the nickel-rich layer being modified with OH− group.
A method for producing a hydrogen-absorbing alloy for batteries which comprises a first step of grinding a hydrogen-absorbing alloy containing at least one rare earth element, nickel and at least one transition metal to prepare alloy powders, a second step of treating the alloy powders in an alkaline aqueous solution, a third step of treating the alloy powders in an acidic aqueous solution, a fourth step of a dehydrogenation treatment to remove hydrogen absorbed in the alloy powders in the presence of acetate ion in an aqueous solution, and a fifth step of adding an alkali to the aqueous solution.
A method for producing a hydrogen-absorbing alloy electrode for batteries which comprises preparing a paste by kneading a hydrogen-absorbing alloy with a thickening agent or a binder and water and coating the resulting paste on a metallic substrate, said hydrogen-absorbing alloy being in the form of powders comprising at least one rare earth element, nickel and at least one transition metal in which the surface portion of the alloy has nickel in metallic state exposed at the surface, pores positioned between the nickel and the nickel, and a nickel-rich layer present on the alloy surface contacting with the pores, the surface of the nickel in metallic state and the surface of the nickel-rich layer being modified with OH− group.
An alkaline storage battery which has a negative electrode comprising a hydrogen-absorbing alloy in the form of powders containing at least one rare earth element, nickel and at least one transition metal in which the surface portion of the alloy has nickel in metallic state exposed at the surface, pores positioned between the nickel and the nickel, and a nickel-rich layer present on the alloy surface contacting with the pores, the surface of the nickel in metallic state and the surface of the nickel-rich layer being modified with OH− group;
Dependencies are inferred from the claim text.