Charlotte, NC, United States
Charlotte, NC, United States

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Patent
Celgard LLC | Date: 2016-08-17

Battery separators and methods are disclosed. The battery separator may be used in a lithium battery. The separator may include a microporous membrane laminated to a coated nonwoven. The coating may contain a polymer and optionally, a filler or particles. The methods may include the steps of: unwinding the microporous membrane and the nonwoven, laminating the nonwoven and microporous membrane, and coating the nonwoven before or after lamination.


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.


Disclosed herein are novel or improved microporous battery separator membranes, separators, batteries including such separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries. Further disclosed are laminated multilayer polyolefin membranes with exterior layers comprising one or more polyethylenes, which exterior layers are designed to provide an exterior surface that has a low pin removal force. Further disclosed are battery separator membranes having increased electrolyte absorption capacity at the separator/electrode interface region, which may improve cycling. Further disclosed are battery separator membranes having improved adhesion to any number of coatings. Also described are battery separator membranes having a tunable thermal shutdown where the onset temperature of thermal shutdown may be raised or lowered and the rate of thermal shutdown may be changed or increased. Also disclosed are multilayer battery separator membranes having enhanced web handling performance during manufacturing processes and coating operations.


Patent
Celgard LLC | Date: 2016-01-20

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.


In accordance with at least selected embodiments, the present disclosure or invention is directed to improved or novel separators, cells, batteries, and/or methods of manufacture and/or use. In accordance with at least certain embodiments, the present disclosure or invention is directed to improved or novel separators such as a separator for a high energy and/or high voltage lithium ion battery which is stable up to a 4.5 volt, or preferably up to a 5.0 volt or higher charging voltage, such as a novel or improved single or multilayer or multiply microporous separator membrane. In accordance with at least selected embodiments, the present application or invention is directed to novel or improved porous membranes or substrates, separator membranes, separators, composites, electrochemical devices, batteries, cells, methods of making such membranes or substrates, separators, cells, and/or batteries, and/or methods of using such membranes or substrates, separators, cells, and/or batteries. In accordance with at least certain embodiments, the present application is directed to novel or improved microporous membranes, battery separator membranes, separators, energy storage devices, batteries including such separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries. In accordance with at least certain selected embodiments, the present invention is directed to a novel or improved separator membrane or separator with or without embedded particles or materials, such as ceramic particles or materials, for example, aluminum oxide, boehmite, and/or barium, and/or with or without novel polymers, such as PVDF or PMP, and/or with or without one or more ceramic coatings, for a battery which is stable up to at least 5 volts in a battery, a novel or improved polymer membrane, or polymeric microporous membrane, adapted for use in a 4.5 volt, 4.7 volt, or 5 volt or higher rechargeable or secondary lithium battery and/or which provides for the energy density of a battery to be increased and/or has excellent oxidation resistance. In accordance with at least particular embodiments, the battery separator membrane described herein is directed to a single or multilayer or composite microporous membrane battery separator which may have excellent oxidation resistance and/or may be stable in a high voltage lithium battery system up to 5 volts or more.


In accordance with at least certain embodiments, the present invention is directed to novel, improved, coated, or treated separator membranes, separators or membrane based separators for lithium batteries. The membranes or separators may include non-woven layers, improved surfactant treatments, or combinations thereof. The separators or membranes are useful for solvent electrolyte lithium batteries, especially rechargeable lithium ion batteries, and provide improved performance, wettability, cycling ability, and/or recharging efficiency.


A functionalized microporous, mesoporous, or nanoporous membrane, material, textile, composite, laminate, or the like, and/or a method of making or using such functionalized membranes. The functionalized porous membrane may be a functionalized microporous, mesoporous, or nanoporous membrane that has a functional molecule attached, such as a functional polymer, to the surface and/or internal fibrillar structure of the membrane.


Novel or improved microporous battery separator membranes, separators, cells, batteries including such membranes, separators, or cells, and/or methods of making such membranes and/or separators, and/or methods of using such membranes and/or separators. In accordance with at least certain embodiments, an improved or novel battery separator for a secondary or rechargeable lithium battery may have low Electrical resistance of less than 0.95 ohm-cm^(2), or in some cases, less than 0.8 ohm-cm^(2). Furthermore, the inventive battery separator membrane may provide a means to achieve an improved level of battery performance in a rechargeable or secondary lithium battery based on a possibly synergistic combination of low Electrical resistance, low Gurley, low tortuosity, and/or a unique trapezoid shaped pore. In accordance with at least certain multilayer embodiments (by way of example only, a trilayer membrane made of two polypropylene layers with a polyethylene layer in between), the inventive microporous membrane or battery separator may have excellent onset and rate of thermal shutdown performance.


Patent
Celgard LLC | Date: 2016-07-22

In accordance with at least selected embodiments, novel or improved porous membranes or substrates, separator membranes, separators, composites, electrochemical devices, batteries, methods of making such membranes or substrates, separators, and/or batteries, and/or methods of using such membranes or substrates, separators and/or batteries are disclosed. In accordance with at least certain embodiments, novel or improved microporous membranes, battery separator membranes, separators, energy storage devices, batteries including such separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries are disclosed. In accordance with at least certain selected embodiments, a separator for a battery which has an oxidation protective and binder-free deposition layer which is stable up to 5.2 volts or more, for example, up to 7 volts, in a battery is disclosed. The deposition layer is preferably a thin, very thin or ultra-thin deposition on a polymeric microporous membrane applied via a binder-free and solvent-free deposition method. By employing such an ultra-thin deposition layer, the energy density of a battery may be increased. In accordance with at least particular embodiments, the battery separator membrane described herein is directed to a multi-layer or composite microporous membrane battery separator which may have excellent oxidation resistance and may be stable in a high voltage battery system up to 5.2 volts or more. In accordance with at least other certain selected embodiments, the present invention is directed to a separator for a battery which has a conductive deposition layer which is stable up to at least 5.2 volts or higher in a battery.


In accordance with at least selected embodiments, novel or improved separator membranes, separators, batteries including such separators, methods of making such membranes and/or separators, and/or methods of using such membranes and/or separators are disclosed or provided. In accordance with at least certain embodiments, an ionized radiation treated microporous polyolefin, polyethylene (PE), copolymer, and/or polymer blend (e.g., a copolymer or blend comprising PE and another polymer, such as polypropylene (PP)) battery separator for a secondary or rechargeable lithium battery and/or a method of making an ionized radiation treated microporous battery separator is disclosed. The ionized radiation treatment may provide a microporous membrane or battery separator having a lower onset temperature of thermal shutdown, an extended thermal shutdown window, physical, dimensional, and/or mechanical integrity maintained at higher temperatures, improved battery safety performance in a rechargeable lithium battery, a treated polyethylene separator membrane with the high temperature performance of a polypropylene membrane or separator membrane, or polypropylene-based trilayer product (by way of example only, a trilayer membrane made of two polypropylene layers with a polyethylene layer in between), reduced thermal shrinkage resulting in both improved thermal stability and high temperature physical integrity, which maintains the separation of cathode and anode in a battery system and avoids thermal runaway in a rechargeable or secondary lithium battery, and/or combinations thereof.

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