Panasonic Intellectual Property Management Co., Ltd.

Akiko Okabe

Fumio Kato

Yasushi Nakamura

Hideaki Ohyama

Shinichi Sumiyama

Kiyoshi Hayashi

Hiroki Takeshima

Provided is an electrode alloy powder that is useful to obtain a nickel-metal hydride storage battery having a high battery capacity and a reduced self-discharge. The alloy powder is: a mixture including particles of a first hydrogen storage alloy having an AB-type crystal structure, and particles of at least one second hydrogen storage alloy selected from the group consisting of a hydrogen storage alloy a having an AB-type crystal structure and a hydrogen storage alloy b having an AB-type crystal structure, wherein an amount of the first hydrogen storage alloy included in the mixture is greater than 50 mass %.

Electrode alloy powder, negative electrode for nickel-metal hydride storage batteries using the same, and nickel-metal hydride storage battery

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;.

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Osaka, Japan

Akiko Okabe