CELGARD, LLC

Improved battery separators, base films or membranes, batteries, cells, devices, systems, vehicles, and/or methods of making and/or using such separators, films or membranes, batteries, cells, devices, systems, vehicles, and/or methods of enhancing battery or cell charge rates, charge capacity, and/or discharge rates, and/or methods of improving batteries, systems including such batteries, vehicles including such batteries and/or systems, and/or the like; biaxially oriented porous membranes, composites including biaxially oriented porous membranes, biaxially oriented microporous membranes, biaxially oriented macroporous membranes, battery separators with improved charge capacities and the related methods and methods of manufacture, methods of use, and the like; flat sheet membranes, liquid retention media; dry process separators; biaxially stretched separators; dry process biaxially stretched separators having a thickness range between about 5 μm and 50 μm, preferably between about 10 μm and 25 μm, having improved strength, high porosity, and unexpectedly and/or surprisingly high charge capacity, such as, for example, high 10C rate charge capacity; separators or membranes with high charge capacity and high porosity, excellent charge rate and/or charge capacity performance in a rechargeable and/or secondary lithium battery, such as a lithium ion battery, for high power and/or high energy applications, cells, devices, systems, and/or vehicles, and/or the like; single or multiple ply or layer separators, monolayer separators, trilayer separators, composite separators, laminated separators, co-extruded separators, coated separators, 1 C or higher separators, at least 1 C separators, batteries, cells, systems, devices, vehicles, and/or the like; improved microporous battery separators for secondary lithium batteries, improved microporous battery separators with enhanced or high charge (C) rates, discharge (C) rates, and/or enhanced or high charge capacities in or for secondary lithium batteries, and/or related methods of manufacture, use, and/or the like, and/or combinations thereof are disclosed or provided.

A microporous film having at least one of the following properties: unrestrained MD shrinkage, when the film is baked unrestrained at 90° C. for 1 hour, of 2% or more; unrestrained MD shrinkage, when the film is baked unrestrained at 105° C. for 1 hour, of 2.5% or more; MD restrained growth, when measured using the MD restrained growth test, of less than or equal to 0.2%; rebound or recovery of 5% or greater when measured by the compressibility test; a max compression greater than or equal to 18% when measured by the compressibility test; swelling in DEC when measured according to the swelling in DEC test of 0.95% or less; the film exhibits a round-shaped, not a slit-shaped opening when subjected to the puncture test; the lamellae of the film have a thickness no greater than 250 nm; a normalized puncture strength above 350 g/16 micron; and having higher modulus and lower elongation before break of less than 40% in the machine direction. Also disclosed is a battery separator, battery, or device comprising at least one microporous film as described herein.

A two-side coated battery separator that has an adhesive layer on each side is described. The adhesive layer on one side is formed from a different coating formulation than the adhesive layer on an opposite side. In some embodiment, an adhesive layer on one side is formed on top of a ceramic layer and an adhesive layer on the other side is formed directly on the battery separator. A battery comprising this two-side coated battery separator is also described.

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.

Disclosed herein are new or improved method for measuring battery separators that are more suitable for modern battery separators and may more accurately predict performance in the battery. Also disclosed are characteristics of an ideal separator that may be measured according to the new or improved methods herein. The ideal separator may comprise one of more of the following properties: low electrical resistance (ER)/σ i approaching infinity; σ e approaching zero when the separator is dry or wet with electrolyte; low or no volume (higher Wh/l); low or no weight (high Wh/kg); anti-compression (z-performance, wet); super strong (XYZ direction strength for processing when dry and wet); all temperature stability (mechanical, electrical, and electro-chemical when wet and dry); and ability to apply infinite force when measuring ISR.

In accordance with at least selected embodiments, a battery separator or separator membrane comprises one or more co-extruded multi-microlayer membranes optionally laminated or adhered to another polymer membrane. The separators described herein may provide improved strength, for example, improved puncture strength, particularly at a certain thickness, and may exhibit improved shutdown and/or a reduced propensity to split.

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.

New and/or improved coatings, layers or treatments for porous substrates, including battery separators or separator membranes, and/or coated or treated porous substrates, including coated battery separators, and/or batteries or cells including such coatings or coated separators, and/or related methods including methods of manufacture and/or of use thereof are disclosed. Also, new or improved coatings for porous substrates, including battery separators, which comprise at least a matrix material or a polymeric binder, and heat-resistant particles with additional additives, materials or components, and/or to new or improved coated or treated porous substrates, including battery separators, where the coating comprises at least a matrix material or a polymeric binder, and heat-resistant particles with additional additives, materials or components are disclosed. Further, new or improved coatings for porous substrates, including battery separators, and new and/or improved coated porous substrates, including battery separators, new or improved coatings for porous substrates, including battery separators, which comprise at least (i) a matrix material or a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a cross-linker, a low-temperature shutdown agent, an adhesion agent, and a thickener, and new and/or improved coated porous substrates, including battery separators, where the coating comprises at least (i) a matrix material or a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a cross-linker, a low-temperature shutdown agent, an adhesion agent, a thickener, a friction-reducing agent, and a high-temperature shutdown agent are disclosed.

A novel or improved base film for impregnation, impregnated base film, product incorporating the impregnated base film, and/or related methods as shown, claimed or described herein.

A heat-resistant sticky coating for use on a membrane or lithium ion battery separator is disclosed. The coating has at least improved dry adhesion to an electrode for a lithium ion battery. The coating includes heat-resistant particles with a water-soluble sticky polymer on their surface. The water-soluble sticky polymer may be a polyethylene oxide (PEO). The coating may also include particles of water-insoluble sticky polymer. The water-insoluble sticky polymer may be a polyvinylidene fluoride (PVDF) homopolymer, copolymer, or terpolymer. The water-insoluble sticky polymer may be in the same layer of the coating as the heat-resistant particles with the water-soluble sticky polymer on their surface, or it may be in a different layer. A method for forming the heat-resistant sticky coating is also disclosed.