Toyo Tanso Co., Ltd.

National Institute of Technology

Tetsuya Yuki

Yoshiaki Hirose

Hiroshi Okano

Toshihiro Hosokawa

Nobuya Misaki

Tomofumi Kurosaki

Takurou Tsuruoka

A positive electrode for an air battery that can remarkably improve the battery performance is provided by uniformly dispersing fine Nb (Nb oxide) therein. An air battery using the positive electrode as well as a method of manufacturing the positive electrode is also provided. A positive electrode for an air battery includes an expanded graphite sheet containing expanded graphite and Nb dispersed within the sheet. It is desirable that the Nb be contained in a weight proportion of from 5 ppm to 50000 ppm with respect to the expanded graphite.

Positive electrode for air battery, air battery using the positive electrode, and method of manufacturing the positive electrode

An expanded graphite sheet is provided that can remarkably improve the quality and yield rate by preventing chipping and cracks in the surface in molding the sheet into a desired shape by inhibiting degradation in the flexibility while reducing the ash content to a certain degree. An expanded graphite sheet () has a flexibility of 25 times or greater, as determined in a flexibility test in which the flexibility is defined as the number of times the expanded graphite sheet () can be bent using a flexibility testing device having a rotator () to which one end of a plate-shaped expanded graphite sheet () is fixed, a weight () fixed to the other end of the expanded graphite sheet (), and a bending position determining member () for determining a bending position of the expanded graphite sheet () when the rotator () is rotated.

Expanded graphite sheet and method of manufacturing same

A crucible protection sheet is provided that can prevent damages to an inner crucible, hinder an outer crucible from silicon-carbidization, and transmit heat from the outer crucible to the inner crucible uniformly. In a crucible having an inner crucibleand an outer crucible, the crucible protection sheet is arranged between the two crucibles and is made of expanded graphite. The planar thermal conductivity is 120 W/(m&#xb7;K) or higher, the gas permeability is less than 1.0&#xd7;10cm/s, and the compression ratio is 20% or higher when the sheet is compressed in a thickness direction at a pressure of 34.3 MPa. Since the compression ratio is high, the effect of preventing breakage is great when inserting the inner crucible, improving workability and preventing the inner crucible from tilting inside the outer crucible. In addition, even though the compression ratio is high, the thermal conductivity is kept to such a degree that the inner crucible can be heated uniformly, and the gas shielding capability is also ensured. As a result, the outer crucible is prevented from silicon-carbidization and thickness decrease.

Crucible protection sheet and crucible apparatus using the crucible protection sheet

An object is to provide an expanded graphite sheet at the use stage that can prevent can prevent degradation in product quality and deterioration in product yield by inhibiting the expanded graphite sheet from containing impurities even when the expanded graphite sheet is actually used. An expanded graphite sheet at the use stage in a condition in which the expanded graphite sheet is packed with a packing material and thereafter removed from the packing material, characterized in that all of the amounts of Al, B, Be, Ca, Cu, Fe, Li, Mg, Ni, S, Ti, V, and Zn as determined by an ICP emission spectroscopy method, the amounts of K and Na as determined by an atomic absorption spectrometry method, and the amount of Si as determined by an absorption spectrophotometry method are at a level less than the detection limit.

Expanded graphite sheet

There is provided a mold release sheet () disposed between silica powder M and an inner face of an outer memberof a mold and made of expanded graphite. The mold release sheet has a gas permeability represented by the following equation (1) from 5.0&#xd7;10cm/s to 1.0&#xd7;10cm/s. Gas permeability=Q&#xb7;L/(&#x394;P&#xb7;A) (1). In this equation (1), Q is the gas flow rate (Pa&#xb7;cm/s), &#x394;P is the pressure difference (Pa) between two chambers, A is the gas transmission area (cm) of the mold release sheet, which is the area of a passage that allows the two chambers to communicate with each other, and L is the thickness (cm) of the mold release sheet.

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Mitoyo, Japan

Tetsuya Yuki