Toray Battery Separator Film Co., Ltd.

Toray Industries, Inc.

Tonen Chemical Corporation

National Institute of Advanced Industrial Science and Technology

Takeshi Ishihara

Koichi Kono

Satoshi Miyaoka

Patrick Brant

Donna Jean Crowther

Kazuhiro Yamada

Hiroyuki Ozaki

Satoshi Ueki

Masami Sugata

Kohtaro Kimishima

Kenji Tsuchihara

Kunihiko Imanishi

Hideaki Hagihara

Naoki Toyota

Takeshi Shiono

Ban The Hoang

Masatoshi Horii

Hideaki Wakabayashi

Satoshi Miyaoki

A method suppresses membrane thickness variation and air resistance variation after a compression at 60&#xb0; C. or 80&#xb0; C. Stretching is performed at least twice in at least different axial directions before the extraction of the solvent, and at the same time, at least one of (i) and (ii) is satisfied. (i) The step (c) is a first stretching step of stretching the sheet-shaped product at least once in a sheet transport direction (MD direction) and at least once in a sheet width direction (TD direction) individually, and the MD stretching magnification and the TD stretching magnification in the step (c) satisfy (TD stretching magnification&#x2265;MD stretching magnification&#x2212;2). (ii) The stretching temperature (T1) of a first axial stretching performed firstly in the step (c) and the maximal stretching temperature (T2) of a second stretching performed after the first axial stretching satisfy (T1&#x2212;T2&#x2265;0).

Microporous membrane lithium ion secondary battery and method of producing the microporous membrane

A microporous membrane has average membrane thickness of 15 &#x3bc;m or less, and relative impedance A after a heat compression treatment under a pressure of 4.0 MPa at 80&#xb0; C. for 10 minutes of 140% or less, the relative impedance A being obtained by the equation below: Relative impedance A=(impedance measured at 80&#xb0; C. after the heat compression treatment)/(impedance measured at room temperature prior to the heat compression treatment)&#xd7;100.

Microporous membrane, lithium ion secondary battery and method of producing the microporous membrane

Provided is a microporous polyolefin membrane which has excellent oxidation resistance and electrolyte injection performance and further has excellent permeability and strength balance. The multilayer, microporous polyolefin membrane has a first microporous layer containing polypropylene. The electrolyte injection performance is 20 seconds or less, at least one surface layer is the first microporous layer, and the PP distribution in the first microporous layer is uniform in the in-plane direction.

Multilayer, microporous polyolefin membrane, and production method thereof

A polyolefin microporous membrane includes a polyethylene composition, and 0.5% or more but less than 5% by mass of polypropylene, wherein the polyethylene composition includes polyethylene having a mass average molecular weight of 2.5&#xd7;10to 5&#xd7;10and ultrahigh molecular weight polyethylene having a mass average molecular weight of 1&#xd7;10to 3&#xd7;10in an amount of more than 5% by mass and not more than 50% by mass based on 100% by mass of polyethylene composition and has a molecular weight distribution (Mw/Mn) of 5.0 to 300, and the polyolefin microporous membrane has an injection of electrolyte of 20 seconds or less and a uniform polypropylene distribution in at least one plane perpendicular to the thickness direction.

Polyolefin microporous film and method of producing same

A multilayer microporous membrane including polymer and having a shutdown temperature of &#x2266;130.5&#xb0; C. and a storage stability of 0.3V or less.

Microporous polymeric membranes, battery separators, and production methods therefor

A polyolefin microporous membrane is produced by forming a gel-like molding using a polyolefin resin containing polypropylene, and stretching the molding in at least one direction, followed by washing, the polyolefin microporous membrane having an injection of electrolyte of 20 seconds or less and a uniform polypropylene distribution in at least one plane perpendicular to the thickness direction.

Polyolefin microporous film and method for producing same

A microporous membrane includes a low melting polypropylene, the low melting polypropylene being a polypropylene homopolymer or copolymer having an MFR&#x2267;2.0&#xd7;10, a Tm of 85.0&#xb0; C. to 130.0&#xb0; C., and a Te-Tm&#x2266;10&#xb0; C.

Microporous film, methods for making such film, and use for such film as battery separator film

The invention relates to microporous membranes comprising polymer and having well-balanced permeability, shutdown temperature, and pin puncture strength. The invention also relates to methods for making such membranes, and the use of such membranes as battery separator film in, e.g., lithium ion secondary batteries.

Microporous membranes, methods for making such membranes, and the use of such membranes as battery separator film

The invention relates to microporous membranes comprising polymer and having well-balanced permeability, shutdown temperature, and pin puncture strength. The invention also relates to methods for making such membranes, and the use of such membranes as battery separator film in, e.g., lithium ion secondary batteries. The membrane has a shutdown temperature &#x3c;130.5&#xb0; C.

The invention relates to microporous membranes having at least two layers, a first layer comprising polymethylpentene and a second layer which comprises a polymer and has a composition that is not substantially the same as that of the first layer. The invention also relates to methods for making such membranes and the use of such membranes as battery separator film in, e.g., lithium ion batteries.

Multi-layer microporous film

The invention relates to a microporous membrane having a relatively low heat shrinkage values along planar axes of the membrane. The invention also relates to a battery separator formed by such microporous membrane, and a battery comprising such a separator. Another aspect of the invention relates to a method for making the multi-layer, microporous polyolefin membrane, a method for making a battery using such a membrane as a separator, and a method for using such a battery.

Microporous films, methods for their production, and applications thereof

The invention relates to microporous polymeric membranes suitable for use as battery separator film. The membrane comprises polyethylene, polypropylene, and polymethylpentene. The invention also relates to a method for producing such a membrane, batteries containing such membranes as battery separators, methods for making such batteries, and methods for using such batteries.

Microporous film, process for production of the film, and use of the film

The present invention relates to microporous membranes comprising polymer and having well-balanced permeability and heat shrinkage, especially heat shrinkage at elevated temperature. The invention also relates to methods for making such membranes, and the use of such membranes as battery separator film in, e.g., lithium ion secondary batteries.

The invention relates to microporous membranes having high meltdown temperature, high air permeability, and high puncture strength. The invention also relates to the production of such membranes and the use of such membranes as battery separator film.

Microporous membranes, methods for making these membranes, and the use of these membranes as battery separator films

The invention relates to microporous membranes having high meltdown temperature, low shutdown temperature, and resistance to heat shrinkage at elevated temperature. The membranes can be produced by stretching a sheet comprising polymethylpentene, polyethylene, and diluent, and then removing the diluent. The membranes can be used as battery separator film in, e.g., lithium ion batteries.

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Nasushiobara, Japan

Takeshi Ishihara