Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Shinichi Sumiyama

Fumio Kato

Yasushi Nakamura

Kiyoshi Hayashi

Hideaki Ohyama

Akiko Okabe

Kenji Yamamoto

Hiroki Takeshima

Susumu Kato

Hidekatsu Izumi

Yasuhiko Syoji

Hirofumi Iwaki

Shunsuke Uzuka

Disclosed is an alloy powder for electrodes for nickel-metal hydride storage batteries having a high battery capacity and being excellent in life characteristics and high-temperature storage characteristics. The alloy powder includes a hydrogen storage alloy containing elements L, M, Ni, Co, and E. L includes La as an essential component. L includes no Nd, or when including Nd, the percentage of Nd in L is less than 5 mass %. The percentage of La in the hydrogen storage alloy is 23 mass % or less. M is Mg, Ca, Sr and/or Ba. A molar ratio &#x3b1; to a total of L and M is 0.045&#x2264;&#x3b1;&#x2264;0.133. A molar ratio x of Ni to the total of L and M is 3.5&#x2264;x&#x2264;4.32, and a molar ratio y of Co is 0.13&#x2264;y&#x2264;0.5. The molar ratios x and y, and a molar ratio z of E to the total of L and M satisfy 4.78&#x2264;x+y+z&#x3c;5.03.

Alloy powder for electrodes, negative electrode for nickel-metal hydride storage batteries including the same, and nickel-metal hydride storage battery including the same

Provided is an alloy powder for an electrode which enables an alkaline storage battery to have both excellent discharge characteristics and excellent life characteristics. The alloy powder includes a hydrogen storage alloy including an element L, Mg, Ni, Al, and an element M. The element L is at least one selected from the group consisting of group 3 elements and group 4 elements of the periodic table (excluding Y). The element Mis at least two selected from the group consisting of Ge, Y, and Sn. A molar proportion x of Mg in a total of the element L and Mg is 0.008&#x2266;x&#x2266;0.54. A molar proportion y of Ni, a molar proportion &#x3b1; of Al, and a molar proportion &#x3b2; of the element M, per the foregoing total is 1.6&#x2266;y&#x2266;4, 0.008&#x2266;&#x3b1;&#x2266;0.32, and 0.01&#x2266;&#x3b2;&#x2266;0.12, respectively.

Alloy powder for electrode, negative electrode for alkaline storage battery using the same, and alkaline storage battery

There is provided a nickel-metal hydride storage battery with suppression of rise in internal pressure, allowing suppression of alkaline electrolyte leakage even when two or more of the batteries are used. The battery includes: positive and negative electrodes; a separator interposed therebetween; and an alkaline electrolyte. The negative electrode includes: a material mixture layer including hydrogen storage alloy powder capable of electrochemically absorbing and releasing hydrogen; and a water-repellent layer including a first polymer including tetrafluoroethylene as monomer units, formed on the material mixture layer. The separator includes: a primary layer having a non-woven fabric structure of fibers; and a composite layer formed on the primary layer and being in contact with the water-repellent layer. The composite layer includes: fibers in continuity with the non-woven fabric structure; and a second polymer including tetrafluoroethylene as monomer units. The composite layer has a water contact angle of 10 to 80&#xb0;.

Nickel-hydrogen storage battery and battery pack

An alkaline storage battery includes: a cylindrical case having a side wall including an opening end portion and a bottom; a sealing plate; a gasket interposed between the sealing plate and the opening end portion; and a sealant between the gasket and the opening end portion. The side wall has an annular groove opened at an outer surface thereof, and an inwardly curl portion at the opening end portion. In at least part of the groove, the minimum width L1 is within 0.2 mm. The sealant includes a polyamide resin formed such that when two test-plate materials are bonded together at bonding faces facing each other via a bonding portion of the sealant, and moved in parallel with the bonding faces and in opposite directions to have a relative displacement within 0.5 to 5 mm, a stress at least 0.02 N/mmis applied to the bonding portion.

Cylindrical alkaline storage battery

An alkaline dry battery of this invention includes: a positive electrode including at least one of a manganese dioxide powder and a nickel oxyhydroxide powder; a negative electrode including a zinc alloy powder; a separator interposed between the positive electrode and the negative electrode; an alkaline electrolyte; and a battery case for housing the positive electrode, negative electrode, the separator, and the alkaline electrolyte. The negative electrode further includes a surfactant that adsorbs to a surface of the zinc alloy powder during a non-discharge period and promptly desorbs from the surface of the zinc alloy powder upon start of discharge without impeding ion transfer in the alkaline electrolyte.

Alkaline dry battery

A gelled negative electrode contains zinc powder, alkaline electrolyte, and a gelling agent. The specific surface area of the zinc powder is in the range between 0.025 and 0.045 m/g. The gelling agent contains, as a main component, a cross-linked polymer formed by radical polymerization in a non-benzene solvent, specifically, a cross-linked poly(meth)acrylic acid (or salt) formed by radical polymerization of a (meth)acrylic acid (or slat) in a non-benzene solvent.

Gelled negative electrode for alkaline battery and alkaline battery

The opening portion of a battery case is sealed with a sealing plate using a gasket. The potential of electrolytic manganese dioxide in a positive electrode active material is in the range from 275 to 320 mV. The volume of a closed space formed between the gasket and positive and negative electrodes in the battery case is in the range from 2.0 to 6.0% of the volume inside the battery formed by the battery case and the sealing plate.

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Osaka, Japan

Shinichi Sumiyama