Santoku Corporation

Takayuki Otsuki

Toshio Irie

Shinji Ikeuchi

Akiyasu Ota

Yasunori Yanagi

Hiroki Hayashi

Noboru Nishigaki

Atsushi Sakuta

Yoshiharu Takata

A low-cost hydrogen storage material has hydrogen absorption (storage) and desorption properties suitable for hydrogen storage. A hydrogen storage container including the hydrogen storage material and a hydrogen supply apparatus including the hydrogen storage container are disclosed. The hydrogen storage material includes an alloy having a specific elemental composition represented by Formula (1), in which, in a 1000×COMP image of a cross section of the alloy obtained by EPMA, a plurality of phases enriched with R are present, the phases having phase diameters of 0.1 μm or more and 10 μm or less, and 100 or more sets of combinations of two phases in the phases are present in a visual field of 85 μm×120 μm in the COMP image, the shortest separation distance between the two phases being 0.5 to 20 μm.[Chem. 1]TiRM1FeMnM2C  (1)

Hydrogen storage material, hydrogen storage container, and hydrogen supply apparatus

Hydrogen storage alloy powder, an anode, and a nickel-hydrogen rechargeable battery are provided, which are excellent in low-temperature characteristics and both in initial activity and cycle life at the same time, which properties are trading-off in conventional nickel-hydrogen rechargeable batteries. The alloy powder has a composition represented by formula (1) RMgNiAlM(R: rare earth elements including Sc and Y, or the like; 0.005&#x2266;a&#x2266;0.40, 3.00&#x2266;b&#x2266;4.50, 0&#x2266;c&#x2266;0.50, 0&#x2266;d&#x2266;1.00, 3.00&#x2266;b+c+d&#x2266;4.50), and has an arithmetical mean roughness (Ra) of the powder particle outer surface of not less than 2 &#x3bc;m, or a crushing strength of not higher than 35,000 gf/mm.

Hydrogen absorption alloy powder, negative electrode, and nickel-hydrogen secondary cell

Provided are hydrogen storage alloy powder capable of providing a nickel-hydrogen rechargeable battery with simultaneous excellence in initial activity, discharge capacity, and cycle characteristics, which are otherwise in a trade-off relationship, an anode for a nickel-hydrogen rechargeable battery as well as a nickel-hydrogen rechargeable battery employing the same. The hydrogen storage alloy has a particular composition represented by formula (1), RMgNiAlM, and has at its outermost surface a Mg-rich/Ni-poor region having a composition with a Mg molar ratio higher than that in formula (1) and a Ni molar ratio lower than that in formula (1), and has inside a Mg/Ni-containing region having a composition with a Mg molar ratio lower than and a Ni molar ratio higher than those in the Mg-rich/Ni-poor region.

Hydrogen-absorbing alloy powder, negative electrode, and nickel hydrogen secondary battery

A safe and industrially advantageous production method is disclosed for producing a rare earth-Mg&#x2014;Ni based hydrogen storage alloy which realizes production of a nickel-hydrogen rechargeable battery having excellent cycle characteristics and a large capacity. The method is for producing a rare earth-Mg&#x2014;Ni based hydrogen storage alloy including element A, Mg, and element B, wherein element A is composed of at least one element R selected from rare earth elements including Sc and Y, and optionally at least one element selected from Zr, Hf, and Ca, and element B is composed of Ni and optionally at least one element selected from elements other than element A and Mg. The method includes first step of mixing an alloy consisting of elements A and B and Mg metal and/or a Mg-containing alloy having a melting point not higher than the melting point of Mg metal, and second step of heat-treating a mixture obtained from first step for 0.5 to 240 hours at a temperature 5 to 250&#xb0; C. lower than a melting point of the rare earth-Mg&#x2014;Ni based hydrogen storage alloy to be obtained.

Process for production of (rare earth)-Mg-Ni-based hydrogen storage alloy

A hydrogen storage alloy wherein elution of Co, Mn, Al, and the like elements into an alkaline electrolyte is inhibited, an anode for a nickel-hydrogen rechargeable battery employing the alloy, and a nickel-hydrogen rechargeable battery having the anode.

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Kobe, Japan

Takayuki Otsuki