CELGARD, LLC

An improved multilayer laminated microporous battery separator for a lithium ion secondary battery, and/or a method of making or using this separator is provided. The preferred inventive dry process separator is a tri-layer laminated Polypropylene/Polyethylene/Polypropylene microporous membrane with a thickness range of 12 μm to 30 μm having improved puncture strength and low electrical resistance for improved cycling and charge performance in a lithium ion battery. In addition, the preferred inventive separator's or membrane's low Electrical Resistance and high porosity provides superior charge rate performance in a lithium battery for high power applications.

In one aspect, microporous membranes are described herein demonstrating composite architectures and properties suitable for electronic and/or optical applications. In some embodiments, a composite membrane described herein includes a microporous polymeric matrix or substrate having an interconnected pore structure and an index of refraction and an electrically conductive coating deposited over one or more surfaces of the microporous polymeric matrix. In other embodiments, the pores are filled and the membranes are substantially transparent.

Disclosed or provided are high melt temperature microporous Lithium-ion rechargeable battery separators, shutdown high melt temperature battery separators, battery separators, membranes, composites, and the like that preferably prevent contact between the anode and cathode when the battery is maintained at elevated temperatures for a period of time, methods of making, testing and/or using such separators, membranes, composites, and the like, and/or batteries, Lithium-ion rechargeable batteries, and the like including one or more such separators, membranes, composites, and the like.

A system for differentiating short circuiting in a battery includes: a detector coupled to the battery; a monitor in communication with the detector, the monitor including a profile of a battery shorting behavior, and a comparator for matching data from the detector to the profile; and a controller for taking action based upon information from the detector. A method for detecting short circuiting in a battery includes the steps of: detecting a behavior of the battery; comparing the behavior of the battery to a predetermined battery behavior profile; determining the type of short based on the comparison; and taking mitigating action based on the determination. The system/method may monitor: temperature of the battery, heat generation from the battery, current flow through the battery, voltage drop across the battery, and/or combinations thereof. The system/method discriminates between the various battery shorting behaviors for aggressive response or passive response.

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 <0.80 microns (μm); or an interply adhesion as defined by a peel strength >60 grams.

Disclosed herein is an improved membrane, separator and/or method for forming a multilayer microporous membrane for use in an improved battery separator, particularly a battery separator for a lithium ion secondary battery. Also disclosed herein is the multilayer microporous membrane formed by this method, which has properties that compete with or exceed those of wet process, coated or uncoated, membranes that are also useable in battery separators. Also disclosed are battery separators comprising the multilayer microporous membrane and batteries, vehicles, or devices comprising the separators. The method may comprise at least the following steps: (1) forming a stretched first non-porous precursor film that has pores due to the stretching of a first non-porous precursor film; (2) separately forming a second stretched non-porous precursor film that has pores due to the stretching of a second non-porous precursor film; and then (3) laminating the stretched first non-porous precursor and the stretched second non-porous precursor.

A microporous membrane is made by a dry-stretch process and has substantially round shaped pores and a ratio of machine direction tensile strength to transverse direction tensile strength in the range of 0.5 to 5.0. The method of making the foregoing microporous membrane includes the steps of: extruding a polymer into a nonporous precursor, and biaxially stretching the nonporous precursor, the biaxial stretching including a machine direction stretching and a transverse direction stretching, the transverse direction stretching including a simultaneous controlled machine direction relax.

Novel or improved microporous single or multilayer battery separator membranes, separators, batteries including such membranes or separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries are provided. In accordance with at least certain embodiments, a multilayer dry process polyethylene/polypropylene/polyethylene microporous separator which is manufactured using the inventive process which includes machine direction stretching followed by transverse direction stretching and a subsequent calendering step as a means to reduce the thickness of the multilayer microporous membrane, to reduce the percent porosity of the multilayer microporous membrane in a controlled manner and/or to improve transverse direction tensile strength. In a very particular embodiment, the inventive process produces a thin multilayer microporous membrane that is easily coated with polymeric-ceramic coatings, has excellent mechanical strength properties due to its polypropylene layer or layers and a thermal shutdown function due to its polyethylene layer or layers. The ratio of the thickness of the polypropylene and polyethylene layers in the inventive multilayer microporous membrane can be tailored to balance mechanical strength and thermal shutdown properties.

Provided herein are seam tapes and related methods. The seam tapes can be compatible with polyolefin-based waterproof/breathable (w/b) membranes, including polypropylene (PP) w/b membranes and/or polyethylene (PE) w/b membranes. Also provided are seams sealed by means of these seam tapes, as well as materials, fabrics, and garments including one or more of these sealed seams.

A membrane is a microporous sheet made of a blend of a first ultra high molecular weight polyolefin and a second ultra high molecular weight polyolefin. Each polyolefin has a molecular weight, both of those molecular weights are greater than 1 million, and one molecular weight is greater than the other. Additionally, the intrinsic viscosity (IV) of the membrane may be greater than or equal to 6.3.