Japan Vilene Company, Ltd.

Other

National Institute of Advanced Industrial Science and Technology

Sanoh Industrial Co., Ltd.

Jemco Inc.

Ube Exsymo Co., Ltd.

Masanao Tanaka

Toshiaki Takase

Nobutoshi Tokutake

Yoshihiko Kondo

Yasuhiro Ito

Hiroaki Yamazaki

Masaki Hirooka

Kazuya Sato

Koji Kimura

Koichi Kato

Tatsuo Nakamura

Akihiko Kawano

Te Hyon Cho

Yuka Kondo

Hiroshi Ohnishi

Tetsuo Sakai

Hiroyuki Imai

Noriko Miyaguchi

Yoshiaki Kawatsu

Shinji Oota

Kunikazu Nagai

Yoshinori Sato

Ayuka Noguchi

Hiroki Cho

Yoshitaka Mayuzumi

Keisuke Takahashi

Kazuya Tsuda

Yoshikazu Miyata

It is an object of the present invention to provide a nonwoven fabric having mechanical strength which is hardly cut and broken by an external force, and a separator for electrochemical devices using the nonwoven fabric. The inventive nonwoven fabric has a sum of tensile strengths by zero-span per basis weight in the machine direction and the cross-machine direction of 6.5N/50 mm or more. Thus, the strength of the constituent fibers of this nonwoven fabric against an external force is high, and this nonwoven fabric has mechanical strength which is hardly cut and broken by an external force. The separator for electrochemical devices of the present invention is composed of this nonwoven fabric.

Non-woven fabric and separator for electrochemical elements

Disclosed herein is a separator for an electrochemical element, comprising a fibrous structure, wherein the fibrous structure has a first fibrous layer part in which short fibers and/or pulp-like fibers are intertwined with each other, and a second fibrous layer part; some of the short fibers and/or the pulp-like fibers constituting the first fibrous layer part penetrates the second fibrous layer part; and a pore diameter distribution of the fibrous structure satisfies the following formula: 0 μm<Dmax<18 μm, and 0 μm≤(Dmax−Dave)<13 μm, wherein Dmax is a maximum pore diameter (μm) of the fibrous structure, and Dave is an average pore diameter (μm) of the fibrous structure.

Separator for electrochemical element

Disclosed are a separator for lithium ion secondary batteries, having an inorganic layer formed from inorganic particles, characterized in that the inorganic particles have a particle diameter distribution in which the 50% cumulative particle diameter Dis in the range of 100 nm to 500 nm, the 10% cumulative particle diameter Dis 0.5Dor more, and the 90% cumulative particle diameter Dis 2Dor less; a method for manufacturing the separator; and a lithium ion secondary battery using the separator. When the separator is used, there can be produced a lithium ion secondary battery in which a short circuit caused by contraction or melting can be definitely prevented, as well as the current density applied to the electrodes during charging and discharging is uniform so that charging and discharging can be efficiently achieved.

Separator for lithium ion secondary battery, method for manufacture thereof, and lithium ion secondary battery

Disclosed is a lithium ion secondary battery, in which comprises a vinyl alcohol polymer or a derivative thereof in an amount of 0.3 mg or more per 1 mAh of battery capacity in terms of a vinyl alcohol unit moiety content. The lithium ion secondary battery can decrease the battery voltage under high-temperature conditions and cannot be recharged after being exposed to high-temperature conditions.

Lithium ion secondary battery

An alkaline battery separator comprises a fused fiber layer, and a fine fiber layer adjacent to the fused fiber layer and comprising fine fibers and second fusible fibers, which are fused in the fine fiber layer, wherein part of the fine fibers are incorporated into the fused fiber layer, so that in determining a delamination strength between the fused fiber layer and the fine fiber layer, delamination occurs in the fine fiber layer and therefore the determination results in failure. A process for manufacturing the separator includes preparing a fused fiber sheet, preparing a slurry containing fine fibers and second fusible fibers, scooping up the slurry with the fused fiber sheet, to thereby incorporate part of the fine fibers into the fused fiber sheet, and fusing the second fusible fibers in the fused fiber sheet.

Alkaline battery separator, process for production thereof and alkaline batteries

A battery separator comprising a nonwoven fabric, wherein the nonwoven fabric contains (1) superfine fibers having a fiber diameter of 3 &#x3bc;m or less, (2) noncircular fine fibers having a noncircular cross-sectional shape and having a fiber diameter of 3 to 5 &#x3bc;m (excluding 3 &#x3bc;m), the fiber diameter meaning a diameter of a circle having an area the same as that of the noncircular cross-sectional shape, and (3) polypropylene based high-strength composite fibers containing a fusible component on the surface thereof and having a tensile strength of 4.5 cN/dtex or more, and the fusible component contained in the polypropylene based high-strength composite fibers is fused, and a battery comprising the battery separator are disclosed. A battery separator of the present invention has a high electrolyte-holding capacity and is capable of effectively preventing a short circuit, even if the separator is designed to be thinner to enhance the capacity of a battery.

Battery separator and battery comprising same

An alkaline battery separator which enables the preparation of a battery with a good yield and workability is provided. The alkaline battery separator of the present invention comprises a fiber sheet mainly comprising hydrophilicity-imparted polyolefin fibers having a fiber diameter of 8 &#x3bc;m or more, and a part of the hydrophilicity-imparted polyolefin fibers is composed of high-strength fibers having a tensile strength of 5 g/d or more.

Alkaline battery separator and process for producing the same

An alkaline battery comprises an electrode. The electrode has a current collector and an active substance filled in the current collector. The current collector includes a nonwoven fabric fabricated from a plurality of fibers and a nickel-plating film formed on the plurality of fibers. A specific surface area per unit volume of the current collector is 0.13 m/cm-0.35 m/cm.

Alkaline battery, current collector, electrode, and method of manufacturing electrode

Disclosed is a battery separator consisting essentially of a nonwoven fabric having a substantially unilayered structure, wherein an apparent total surface area of fibers per a surface density of the nonwoven fabric is 20 mor more, a thickness of the nonwoven fabric is 0.1 mm or less, a uniformity index of the nonwoven fabric is 0.15 or less, and the nonwoven fabric contains fine fibers having a fiber diameter of 4 &#x3bc;m or less.

Battery separator

An alkaline battery separator which enables the preparation of a battery with a good yield and workability is provided. The alkaline battery separator of the present invention comprises a fiber sheet mainly comprising hydrophilicity-imparted polyolefin fibers having a fiber diameter of 8 &mgr;m or more, and a part of the hydrophilicity-imparted polyolefin fibers is composed of high-strength fibers having a tensile strength of 5 g/d or more.

A battery separator is provided which is hardly broken by tension during the manufacture of batteries, is hardly punctured with a plate flash, and is hardly torn off with a plate edge, thereby hardly causing a short circuit. Accordingly, the separator can facilitate the stable manufacture of the batteries. The battery separator is equipped with a fiber sheet containing a polypropylene fiber having a tensile strength of not less than 10 g/d (denier) and a Young's modulus of not less than 800 kg/mm , said separator having a resistance of not less than 585 gf to puncture by edge, or is equipped with a fiber sheet containing not less than 10 mass % of a polypropylene fiber having a tensile strength of not less than 10 g/d (denier) and a Young's modulus of not less than 800 kg/mm .

An alkaline battery separator comprising a gas-permeable sheet which contains a hydrophilic portion carrying a methacrylic/ethylene copolymer component having a crystallinity of 25% or more on at least a part of a surface of said hydrophilic portion.

Alkaline battery separators

An alkaline battery separator comprising a nonwoven fabric containing one or more mixture layers of entangled short fibers and entangled long fibers, wherein a fiber length of the short fibers is from 1 mm to less than 25 mm, a fiber length of the long fibers is 25 mm or more, and a total thickness of all of the mixture layers accounts for not less than one-third of a whole thickness of the nonwoven fabric is disclosed. The alkaline battery separator according to the present invention exhibits an excellent electrolyte-holding capacity, tensile strength, tear strength and bending resistance, and can be used to stably prepare a battery. Electrode flash rarely penetrate the separator, to thereby cause a short circuit between electrodes.

An alkaline battery separator comprising a fiber sheet containing, on outer surfaces of fibers forming a surface of the fiber sheet, a substance having a peak of a bond energy at 530.5 to 531.5 eV which is measured by an X-ray photoelectron spectrometer at a photoelectron-taking-off angle of about 30&deg;; a fiber sheet containing a larger amount of carboxyl groups bonded to surfaces of fibers forming an inside of the fiber sheet than an amount of carboxyl groups bonded to outer surfaces of fibers forming a surface of the fiber sheet; or a fiber sheet capable of entrapping ammonia in an amount of 0.4 mmol/g or more in average is disclosed.

An alkaline battery separator comprising a hydrophilic nonwoven fabric obtainable by heat-fusing and hydro-entangling (1) polyolefin dividable composite fibers having an average fiber length of 20 to 60 mm, (2) high-strength fibers having an average fiber length of 30 to 60 mm and a fiber strength of 5 g/denier or more, and (3) polyolefin heat-sensitive-adhesive fibers having an average fiber length of 30 to 60 mm, to obtain a heat-fused and hydro-entangled nonwoven fabric by a dry-laid method, and imparting a hydrophilic property to the resulting heat-fused and hydro-entangled nonwoven fabric; these high-strength fibers accounting for 20 to 45 mass % with respect to a total mass of the polyolefin dividable composite fibers, the high-strength fibers and the polyolefin heat-sensitive-adhesive fibers. The alkaline battery separator exhibits an excellent breaking strength, and has practical and sufficient tensile strength and electrolyte-holding capacity properties.

Growing community of inventors

Ibaraki, Japan

Masanao Tanaka