Celgard Inc.

Ronald W Call

Lie Shi

Donald K Simmons

Khuy Van Nguyen

Zhengming Zhang

Ronnie E Smith

Jill V Watson

Xiaomin Zhang

Pankaj Arora

Xiangyun Wei

Shizuo Ogura

C William Fulk, Jr

Tien Dao

Robert A Nark

Wei-Ching Yu

Premanand Ramadass

Ta-Hua Yu

Shawn E Hux

Pierre C Cook

Mark W Ferebee

J Robert Dees

William C Fulk

A multi-layered battery separator for a lithium secondary battery includes a first layer of a dry processed membrane bonded to a second layer of a wet processed membrane. The first layer may be made of a polypropylene based resin. The second layer may be made of a polyethylene based resin. The separator may have more than two layers. The separator may have a ratio of TD/MD tensile strength in the range of about 1.5-3.0. The separator may have a thickness of about 35.0 microns or less. The separator may have a puncture strength of greater than about 630 gf. The separator may have a dielectric breakdown of at least about 2000V.

Multilayer hybrid battery separators for lithium ion secondary batteries and methods of making same

A battery separator comprises a co-extruded, microporous membrane having at least two layers made of extrudable polymers and having: a uniform thickness defined by a standard deviation of &#x3c;0.80 microns (&#x3bc;m); or an interply adhesion as defined by a peel strength &#x3e;60 grams.

Co-extruded, multi-layered battery separator

Method of making a co-extruded, multi-layered battery separator

A microporous battery separator is provided having a first co-extruded multilayered portion and a second co-extruded multilayered portion. The two portions are bonded together. In a preferred embodiment, the battery separator has two substantially identical multilayered portions bonded together face-to-face. Each of the two multilayered portions has at least one strength layer and at least one shutdown layer. Methods for making the battery separators are also provided. Preferably, a tubular multilayered film is extruded, and collapsed onto itself to form a multilayered battery separator precursor. The precursor is then bonded and annealed before it is stretched to form a microporous multilayer battery separator.

Multilayer battery separators

A battery separator is a microporous membrane. The membrane has a major volume of a thermoplastic polymer and a minor volume of an inert particulate filler. The filler is dispersed throughout the polymer. The membrane exhibits a maximum Z-direction compression of 95% of the original membrane thickness. Alternatively, the battery separator is a microporous membrane having a TMA compression curve with a first substantially horizontal slope between ambient temperature and 125&#xb0; C., a second substantially horizontal slope at greater than 225&#xb0; C. The curve of the first slope has a lower % compression than the curve of the second slope. The curve of the second slope is not less than 5% compression. The TMA compression curve is graphed so that the Y-axis represents % compression from original thickness and the X-axis represents temperature.

Battery separator with Z-direction stability

A multi-layered battery separator for a lithium secondary battery includes a first layer of a dry processed membrane bonded to a second layer of a wet processed membrane. The first layer may be made of a polypropylene based resin. The second layer may be made of a polyethylene based resin. The separator may have more than two layers. The separator may have a ratio of MD/TD tensile strength in the range of about 1.5-3.0. The separator may have a thickness of about 35.0 microns or less. The separator may have a puncture strength of greater than about 630 gf. The separator may have a dielectric breakdown of at least about 2000V.

A battery separator comprises a multi-layered film, individual layers of film having been bonded together by heat and pressure, having a peel strength of greater than or equal to 40 grams per inch (1.6 g/mm) and a thickness of &#x2266;25 microns. A method for making a battery separator comprises the steps of: extruding and winding up a first precursor film, extruding and winding up a second precursor film, unwinding the first and second precursor films, stacking up the first and second precursor films to form a single stacked precursor, laminating the single stacked precursor film, winding up the laminated single stacked precursor film, stacking up a plurality of laminated single stacked precursor films, and making microporous the stacked plurality of laminated single stacked precursor films.

Battery separator and method of making same

A multi-layer microporous battery separator which comprises: a high molecular weight polypropylene layer having a melt flow index of &#x2266;1.2 measured at layer; a polyethylene layer; and a high molecular weight polypropylene layer having a melt flow index of &#x2266;1.2 measured at layer. The resulting microporous battery separator which is formed by a dry stretch process produces the microporous battery separator which has a porosity of &#x2266;37% while maintaining a gurley from 13-25 seconds and a thickness of &#x2266;25 microns.

Multilayer separator exhibiting improved strength and stability

The present invention is directed to a battery separator. The battery separator comprises a microporous film having a first portion and a second portion. The first portion is bonded to the second portion. The bond has a strength greater than 5 g/in. The film has a thickness less than 1.7 mils, a Gurley of less than 50 sec/10 cc, and a puncture strength of greater than 400 g/mil.

Battery separator

A method for removing a pin from a battery assembly by the step of providing a separator comprising: a microporous membrane having an exterior surface portion of polypropylene, the polypropylene including at least 50 ppm of metallic stearate, preferably calcium stearate Static and being adapted to exhibit a pin removal force &lE;7100 g.

Battery separator-pin removal

A fusible, structurally stabilized battery separator is disclosed. The separator is formed by extruding a cylindrical parison of a polymer film and quenching the film on both sides with a low temperature fluid stream prior to processing the film to impart microporosity. Most preferably, the film includes at least a polyethylene layer and polypropylene layer.

Growing community of inventors

Rock Hill, SC, United States of America

Ronald W Call