Improved Microlayer Films, Improved Battery Separators, and Related Methods

Abstract

An improved multilayer microporous membrane, base film, or battery separator is provided having various improvements such as improved tensile strength and improved dielectric breakdown strength. [Solution] A battery separator for a lithium battery comprising at least one microporous separator membrane or sub-membrane comprising a plurality of porous or microporous polymeric microlayers or nanolayers, wherein at least one of the individual microlayers or nanolayers comprises a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend, a different or distinct additive, drug, material, and / or filler, or a combination of different or distinct polymers, molecular weight polymers, homopolymers, copolymers, polymer blends, additives, drugs, materials, and / or fillers, compared to adjacent individual microlayers or nanolayers.

Description

Technical Field

[0001] Priority Claim This application claims the benefit and priority under 35 U.S.C. § 119(e)(1) of both U.S. Provisional Patent Application No. 62 / 508,360, filed May 18, 2017, and U.S. Provisional Patent Application No. 62 / 420,781, filed November 11, 2016. These provisional patent applications are hereby incorporated by reference in their entireties.

[0002] According to at least selected embodiments, the present application, disclosure, and invention relate to novel or improved membranes, separator membranes, separators, battery separators, lithium secondary battery separators, multilayer membranes, multilayer separator membranes, multilayer separators, multilayer battery separators, multilayer lithium secondary battery separators, and / or multilayer battery separators, novel or improved batteries, capacitors, fuel cells, lithium batteries, lithium-ion batteries, lithium secondary batteries, and / or lithium-ion secondary batteries, and / or methods of making and / or using such membranes, separator membranes, separators, battery separators, lithium secondary battery separators, batteries, capacitors, fuel cells, lithium batteries, lithium-ion batteries, lithium secondary batteries, and / or lithium-ion secondary batteries, and / or devices, vehicles, or products containing the same. According to at least certain embodiments, the present disclosure or invention relates to novel or improved membrane layers, membranes or separator membranes, battery separators containing such membranes, and / or related methods. According to at least certain selected embodiments, the present disclosure or invention relates to novel or improved porous polymer membranes or separator membranes, battery separators containing such membranes, and / or related methods. According to at least certain embodiments, the present disclosure or invention relates to novel or improved microporous polyolefin membranes or separator membranes, micro-layer membranes, multilayer membranes containing one or more micro-layers or nano-layer membranes, battery separators containing such membranes, and / or related methods. According to at least certain embodiments, the present disclosure or invention relates to novel, optimized, or improved microporous stretched polymer membranes or separator membranes having one or more novel or improved outer layers and / or inner layers, micro-layer membranes, multilayer microporous membranes or separator membranes having outer and inner layers, some of such layers or sub-layers being created by coextrusion and then laminated together to form the above novel, optimized, or improved membrane or separator membrane.In some embodiments, a layer, micro-layer or nano-layer may comprise a homopolymer, copolymer, block copolymer, elastomer, and / or polymer blend. In selected embodiments, at least a layer, micro-layer or nano-layer may comprise different or distinct polymers, homopolymers, copolymers, block copolymers, elastomers, and / or polymer blends. The present disclosure or invention also relates to novel or improved methods of making such membranes, separator membranes, or separators, and / or novel or improved methods of using such membranes, separator membranes or separators, for example, as lithium battery separators. According to at least selected embodiments, the present application or invention is directed to novel or improved multi-layer and / or micro-layer porous or microporous membranes, separator membranes, separators, composites, electrochemical devices, and / or batteries, and / or methods of making and / or using such membranes, separators, composites, devices and / or batteries. According to at least certain selected embodiments, the present application or invention is directed to a novel or improved multi-layered separator membrane, wherein one or more layers of the multi-layer structure are manufactured in a multi-layer or micro-layer co-extrusion die having a plurality of extruders. The novel or improved membranes, separator membranes, or separators described above may preferably demonstrate improved shutdown, improved strength, improved dielectric breakdown strength, and / or reduced tendency to tear. Preferably, improved shutdown, improved strength, improved dielectric breakdown strength, and / or reduced tendency to tear may be demonstrated. BACKGROUND OF THE INVENTION

[0003] Known methods of making microporous two-layer or three-layer membranes for use as battery separator membranes include laminating or adhering two or more single-layer precursors together, or co-extruding more than one membrane layer simultaneously using a co-extrusion die. Such methods are described, for example, in U.S. Patent No. 5,952,120, U.S. Patent Application Publication No. 2014 / 0079980, U.S. Patent No. 5,223,032, U.S. Patent No. 5,240,655, and U.S. Patent Application Publication No. 2005 / 031943.

[0004] In the above method, the balance of strength and / or performance characteristics for use in certain primary and / or secondary batteries, such as lithium-ion rechargeable batteries, cannot be fully optimized. This is especially true when the requirements for the battery separator become more stringent as consumers desire thinner and stronger battery separators. For example, a microporous three-layer film formed by coextrusion of three layers may have reduced strength. Separators formed by laminating single layers also ultimately cannot meet the increasing requirements. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0005] Therefore, there is a need for a new and improved multilayer microporous film, base thin film, or battery separator having various improvements such as improved tensile strength and improved dielectric breakdown strength. MEANS FOR SOLVING THE PROBLEM

[0006] According to at least the selected embodiments, the present application, disclosure and invention can address the above-mentioned needs, problems or issues and / or have new or improved membranes, separator membranes, separators, battery separators, lithium secondary battery separators, multilayer membranes, multilayer separator membranes, multilayer separators, multilayer battery separators, multilayer lithium secondary battery separators, and / or multilayer battery separators, new or improved batteries, capacitors, fuel cells, lithium batteries, lithium ion batteries, lithium secondary batteries, and / or lithium ion secondary batteries, and / or methods of fabricating and / or using such membranes, separator membranes, separators, battery separators, lithium secondary battery separators, batteries, capacitors, fuel cells, lithium batteries, lithium ion batteries, lithium secondary batteries, and / or lithium ion secondary batteries, and / or devices, vehicles or products containing the same can be provided. According to at least some embodiments, the present disclosure or invention relates to new or improved membrane layers, membranes or separator membranes, battery separators containing such membranes, and / or related methods. According to at least some selected embodiments, the present disclosure or invention relates to new or improved porous polymer membranes or separator membranes, battery separators containing such membranes, and / or related methods. According to at least certain embodiments, the present disclosure or invention relates to new or improved microporous polyolefin membranes or separator membranes, micro-layer membranes, multilayer membranes including one or more micro-layers or nano-layer membranes, battery separators containing such membranes, and / or related methods. According to at least certain embodiments, the present disclosure or invention relates to new, optimized or improved microporous stretched polymer membranes or separator membranes having one or more new or improved outer layers and / or inner layers, micro-layer membranes, multilayer microporous membranes or separator membranes having outer and inner layers, some of such layers or sub-layers being created by co-extrusion and then laminated together to form the above-mentioned new, optimized or improved membrane or separator membrane. In some embodiments, a layer, micro The ro layer or the nano layer may include a homopolymer, a copolymer, a random copolymer, a PP and / or a PE copolymer, a block copolymer, an elastomer, and / or a polymer blend. In selected embodiments, at least some layer, micro layer or nano layer may include different or distinct polymers, homopolymers, copolymers, block copolymers, elastomers, and / or polymer blends. The present disclosure or invention also relates to new or improved methods of making such membranes, separator membranes, or separators, and / or new or improved methods of using such membranes, separator membranes or separators, for example, as lithium battery separators. According to at least selected embodiments, the present application or invention is directed to new or improved multi-layer and / or micro-layered porous or microporous membranes, separator membranes, separators, composites, electrochemical devices, and / or batteries, and / or methods of making and / or using such membranes, separators, composites, devices and / or batteries. According to at least certain selected embodiments, the present application or invention is directed to a new or improved multi-layered separator membrane, wherein one or more layers of the multi-layer structure are manufactured in a multi-layer or micro-layer co-extrusion die having a plurality of extruders. The novel or improved membranes, separator membranes, or separators described above may preferably demonstrate improved shutdown, improved strength, improved dielectric breakdown strength, and / or reduced tendency to tear.

[0007] The microporous multilayer battery separators described herein, in some embodiments, exhibit improved safety, strength, and durability compared to previous two-layer, three-layer, or multilayer battery separators. For example, the separator can exhibit increased average dielectric breakdown (DB), increased minimum DB, increased shutdown rate, and increased flexibility, all of which indicate a safer battery separator. The separator can also exhibit increased puncture strength and increased mixed intrusion value, indicating a stronger and more durable battery.

[0008] These properties of the microporous multilayer battery separators described herein are, at least in part, the result of the way the separators are made. This method, in some embodiments, includes at least coextruding two or more polymer mixtures to form a first coextruded two-layer, three-layer, or multilayer thin film, coextruding two or more other polymer mixtures to form a second coextruded two-layer, three-layer, or multilayer thin film, and coextruding two or more additional polymer mixtures to form a third coextruded two-layer, three-layer, or multilayer thin film. Coextrusion typically involves using a coextrusion die with one or more extruders (typically one extruder per layer of the two-layer, three-layer, or multilayer thin film) that supply the die. The polymer mixtures used to form each layer of the first, second, and third two-layer, three-layer, or multilayer thin films may be the same or different. The mixtures may include one polymer, or more than one polymer, such as a polymer blend. Also, more than three two-layer, three-layer, or multilayer thin films may be formed. After the first, second, and third two-layer, three-layer, or multilayer thin films are formed, these thin films are laminated together with two of the thin films formed on opposing faces of one of these thin films to form the optionally preferred microporous battery separator described herein.

[0009] The microporous multilayer battery separator described in this specification can be used in lithium-ion batteries including lithium secondary batteries, resulting in a battery with improved safety and durability.

[0010] The battery separator in this specification can be described in several different ways.

[0011] In a first aspect, a battery separator for a lithium battery is described in this specification. In some embodiments, the battery separator includes at least one microporous separator membrane or sub-membrane including a plurality of porous or microporous polymer micro-layers or nano-layers, wherein at least one of the individual micro-layers or nano-layers includes a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend, or includes different or distinct additives, agents, materials, and / or fillers, or includes a combination of different or distinct polymers, molecular weight polymers, homopolymers, copolymers, random copolymers of ethylene and / or propylene, polymer blends, additives, agents, materials, elastomers, SEPS, SEBS, PVDF, EVOH, PMP, fillers, particles, ceramic particles, beads, fibers, scavengers, crosslinking agents, adhesion promoters, surface modifiers, and / or combinations thereof. In some embodiments, a plurality of the separator membranes or sub-membranes of the polymer micro-layers or nano-layers are laminated to each other or to a microporous polymer membrane. In some embodiments, at least one of the separator membranes or sub-membranes of the polymer micro-layers or nano-layers has at least three micro-layers or nano-layers. Optionally, at least one of the separator membranes or sub-membranes of the polymer micro-layers or nano-layers is made of one or more polyolefins. Optionally, at least one of the separator membranes or sub-membranes of the polymer micro-layers or nano-layers is made of co-extruded dry process polyolefin micro-layers or nano-layers. In some embodiments, at least two of the separator membranes or sub-membranes of the polymer micro-layers or nano-layers. In some embodiments, at least three of the separator membranes or sub-membranes of the polymer micro-layers or nano-layers.

[0012] In another aspect, a lithium battery including any of the battery separators described immediately above is described herein.

[0013] In another aspect, an improved separator, membrane or base thin film is described herein. In some embodiments, the separator is a multilayer separator, membrane, or base thin film comprising one or more microporous coextruded micro multilayer or nano multilayer polymer films or sub-films adapted to be laminated or adhered to another polymer film, wherein at least one of the individual micro or nano layers comprises a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend compared to an adjacent individual micro or nano layer, or comprises different or distinct additives, agents, materials, and / or fillers, or comprises a combination of different or distinct polymers, molecular weight polymers, homopolymers, copolymers, polymer blends, additives, agents, materials, and / or fillers.

[0014] In another aspect, a battery comprising at least one battery separator described in the preceding paragraph is described herein.

[0015] In another aspect, a battery separator or separator membrane is described herein. In some embodiments, the battery separator or separator membrane comprises one or more coextruded micro multilayer films laminated or adhered to another polymer film, and the separator or separator membrane can impart improved strength, e.g., improved puncture strength, at a particular thickness, and can also exhibit improved shutdown and / or reduced tendency to tear, wherein at least one of the individual micro layers comprises a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend compared to an adjacent individual micro layer, or comprises different or distinct additives, agents, materials, and / or fillers, or comprises a combination of different or distinct polymers, molecular weight polymers, homopolymers, copolymers, polymer blends, additives, agents, materials, and / or fillers.

[0016] In another aspect, a battery, particularly a lithium-ion battery, containing at least one separator described in the foregoing paragraph is described herein.

[0017] In another aspect, a battery separator or separator membrane is described herein. The battery separator or separator membrane includes, in some embodiments, one or more coextruded micro-multilayer or nano-multilayer membranes optionally laminated or adhered to another polymeric membrane. The separator or separator membrane may exhibit improved strength, improved puncture strength, and / or improved shutdown and / or reduced tearing tendency at a certain thickness. In some embodiments, at least one of the individual micro-layers or nano-layers includes a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend, or a different or distinct additive, agent, material, and / or filler, or a combination of different or distinct polymers, molecular weight polymers, homopolymers, copolymers, polymer blends, additives, agents, materials, and / or fillers compared to an adjacent individual micro-layer or nano-layer.

[0018] In another aspect, a battery, particularly a lithium-ion battery, containing at least one separator described in the foregoing paragraph is described herein.

[0019] In another aspect, an improved battery separator including a multilayer microporous thin film is described herein. In some embodiments, the multilayer microporous thin film includes 9 or more layers, 12 or more layers, 15 or more layers, 18 or more layers, 21 or more layers, 24 or more layers, 27 or more layers, 30 or more layers. In some embodiments, at least three consecutive layers of the microporous thin film have a thickness of 0.1 to 5 microns, 0.1 to 3 microns, 0.1 to 2.5 microns, or 0.1 to 2.0 microns. In some embodiments, the battery separator itself has a thickness of 1 micron to 30 microns, 2 microns to 20 microns, 3 microns to 15 microns, or 4 microns to 10 microns. In some embodiments, at least three consecutive layers each individually include a polyolefin or a polyolefin blend, and in some embodiments, these layers each include polyethylene, and in some embodiments, each includes polypropylene.

[0020] In some cases, at least three consecutive layers are coextruded layers. In some embodiments, these at least three consecutive layers are laminated with at least one other layer to form a microporous polymer thin film. In some embodiments, this at least one other layer is also a coextruded layer coextruded with at least one other layer. In the above battery separator, the at least one other layer is a coextruded layer. The described battery separator has a puncture strength of 290 gf or more, 300 gf or more, or 310 gf or more in some embodiments.

[0021] In another aspect, a battery, particularly a lithium-ion secondary battery, including one or more of the battery separators described in the preceding paragraphs is described herein. The above battery is particularly more durable at least in embodiments where the battery separator has a puncture strength of 290 gf or more, 300 gf or more, or 310 gf or more.

[0022] In yet another aspect, a microporous multilayer battery separator is described herein. The battery separator includes two or more layers and includes a first region that, when viewed in the z-direction of the thin film using SEM, mostly includes a discontinuous amorphous region; and at least a second region that includes at least one layer. In some embodiments, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more of the amorphous regions in the first region are discontinuous. In some embodiments, the second region includes two or more layers, preferably three or more layers, and an amorphous region having a maximum width of 0.8 microns, a maximum width of 0.7 microns, or a maximum width of 0.6 microns. In some of the embodiments described herein, at least one of the first and second regions includes one or more layers containing a polyolefin. In some embodiments, the first region includes at least one layer containing polyethylene, and the second region includes at least one layer containing polypropylene. Optionally, at least one of the first region and the second region includes a coextruded two-layer, three-layer, or multilayer thin film. Optionally, the first region includes a coextruded two-layer, three-layer, or multilayer thin film. Optionally, the first region and the second region include a coextruded two-layer, three-layer, or multilayer thin film. Optionally, the first region, the second region, and the third region of the microporous multilayer battery separator each include a coextruded two-layer, three-layer, or multilayer thin film. Optionally, at least one of the second and third regions of the microporous multilayer battery separator includes a coextruded two-layer, three-layer, or multilayer thin film. Optionally, the second region includes a coextruded two-layer, three-layer, or multilayer thin film. Optionally, the third region includes a coextruded two-layer, three-layer, or multilayer thin film.

[0023] In another aspect, a battery, particularly a lithium-ion battery, including at least one separator described in the preceding paragraphs is described herein.

[0024] In another aspect, a battery separator comprising a multi-layer microporous thin film having an average dielectric breakdown (DB) value higher than that of a typical three-layer microporous thin film having at least one of the same thickness, Gurley, and porosity as the multi-layer microporous thin film. For example, the average DB value may be 1 to 35% higher, 5 to 35% higher, 10 to 35% higher, 15 to 35% higher, or 20 to 35% higher. In some embodiments, the minimum DB value of the microporous multi-layer thin film of the battery separator described herein may be higher than that of a typical or conventional three-layer microporous thin film having the same thickness, Gurley, and / or porosity as the multi-layer microporous thin film. For example, the minimum DB value may be 3 to 20% higher, 5 to 15% higher, or 10 to 15% higher than that of a three-layer microporous thin film having the same thickness, Gurley, and / or porosity as the multi-layer microporous thin film. Optionally, the multi-layer microporous thin film may include 9 or more layers, 12 or more layers, 15 or more layers, 18 or more layers, 21 or more layers, 24 or more layers, 27 or more layers, or 30 or more layers. In some embodiments, at least one of such layers includes a polyolefin or a polyolefin blend. The polyolefin blend may be a polyethylene or a polyethylene blend or a polypropylene or a polypropylene blend. In some other embodiments, the multi-layer microporous thin film having a dielectric breakdown value herein may include a first region including 2 or more layers and a second region including at least one layer. The first region may include polypropylene and an amorphous region that is mostly discontinuous when viewed in the z-direction of the thin film using SEM. In some embodiments, the multi-layer microporous thin film of the battery separator having improved dielectric breakdown described herein may include: (1) a first region including 2 or more layers, a second region including at least one layer, and a third region including at least one layer. The first region may include polypropylene and an amorphous region that is mostly discontinuous when viewed in the z-direction (or thickness direction) of the thin film using SEM.

[0025] In another aspect, a battery, particularly a lithium-ion battery, comprising at least one separator as described in the foregoing paragraph is described herein.

[0026] In another aspect herein, when measured using mercury intrusion porosimetry, a battery separator comprising a multi-layer microporous thin film showing a mercury intrusion value of logarithmic differential intrusion of 5 mL / g or less, 4.5 mL / g or less, 4 mL / g or less, or 3.5 mL / g or less at a pressure sufficient to fill the pores with mercury. In another aspect, a battery, particularly a lithium-ion battery, comprising at least one separator as described in the foregoing paragraph is described herein.

[0027] In another aspect, a battery separator comprising a multi-layer microporous thin film having a Macmillan number greater than 5, greater than 5.5, greater than 6, greater than 6.5, greater than 7, greater than 8, greater than 9, or greater than 10 is described herein. In another aspect, a battery, particularly a lithium-ion battery, comprising at least one separator as described in the foregoing paragraph is described herein.

[0028] In another aspect herein, a battery separator comprising a multi-layer microporous thin film having a tortuosity value of 1.6 or greater, 1.8 or greater, or 2.0 or greater is described herein. In some embodiments, the battery separator herein is a microporous battery separator. In some embodiments, the battery separator is a microporous multi-layer battery separator.

[0029] In another aspect, a battery, particularly a lithium-ion battery, comprising at least one separator as described in the foregoing paragraph is described herein.

[0030] In another aspect, a battery separator comprising a multilayer microporous thin film exhibiting a pin removal force of less than 50 Newtons, 40 Newtons, 30 Newtons, 20 Newtons, 15 Newtons, or 10 Newtons.

[0031] In another aspect, a battery, particularly a lithium-ion battery, comprising at least one membrane or separator described in the preceding paragraphs is described herein. The battery may preferably have a membrane or separator that is a dry process or dry stretching process polyolefin-based membrane, particularly a blown or bubble extrusion MD stretch or MD+TD stretch membrane, but other membranes such as slot die extrusion or casting, wet process, BNBOPP, BOPP, particle stretching, and / or equivalent membranes may be used. For example, a dry process multilayer PO membrane may be laminated to a BNBOPP membrane.

[0032] In another aspect, a battery separator is described herein. The battery separator comprises a microporous multilayer thin film comprising: (1) a first region comprising two or more layers; (2) a second region comprising two or more layers on a first surface of the first region; and (3) a third region comprising two or more layers on a surface opposite the first surface of the first region, wherein at least one of the first, second, or third regions comprises PE and has a lower crystallinity than the PE-containing layer of the three-layer microporous thin film when measured by DSC, where the three-layer microporous thin film has the same thickness as the multilayer microporous thin film. For example, the crystallinity may be 1-20% lower, 1-15% lower, 1-10% lower, or 1-5% lower.

[0033] In another aspect, a battery, particularly a lithium-ion battery, comprising at least one separator described in the preceding paragraphs is described herein.

[0034] In another aspect, a battery separator including a multilayer microporous thin film having a mixed intrusion (N) value greater than 380 N, greater than 400 N, greater than 450 N, greater than 500 N, greater than 550 N, greater than 600 N, greater than 650 N, or greater than 700 N is described herein.

[0035] In another aspect, a battery, particularly a lithium-ion battery, including at least one separator described in the preceding paragraph is described herein.

[0036] In another aspect, a battery separator is described herein. The battery separator includes a microporous thin film having an electrical resistance value of 2 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, 1.0 or less in some embodiments.

[0037] In another aspect, a battery, particularly a lithium-ion battery, including at least one separator described in the preceding paragraph is described herein.

[0038] In another aspect, a battery separator including a multilayer microporous thin film having a mixed intrusion value of 380 N or more, 400 N or more, 450 N or more, 500 N or more, 550 N or more, 600 N or more, 650 N or more, or 700 N or more is described.

[0039] In another aspect, a battery, particularly a lithium-ion battery, including at least one separator described in the preceding paragraph is described herein.

[0040] In another aspect, a battery separator including a multilayer microporous thin film having an electrical resistance of 2.0 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, 1.1 or less, or 1.0 or less is described.

[0041] In another aspect, a battery, particularly a lithium-ion battery, comprising at least one separator described in the foregoing paragraph is described herein.

[0042] In another aspect, a battery separator comprising a multilayer microporous thin film including two or more layers or micro-layers and a region containing polyethylene in one or more of said layers or micro-layers. When the above region is tested according to the machine learning test described herein, at least one of the following is satisfied: W T x'≧-4, W T x'≧-2.654, W T x'≧1.3, and W T x'≧2, W T x'≧2 is most preferred.

[0043] In another aspect, a battery, particularly a lithium-ion battery, comprising at least one separator described in the foregoing paragraph is described herein.

[0044] In another aspect, a battery separator comprising a multilayer microporous thin film including two or more layers or micro-layers and a region containing polypropylene in one or more of said layers or micro-layers. When the above region is tested according to the machine learning test described herein, at least one of the following is satisfied: W T x'≧-5, W T x'≧-3, W T x' ≧0, W T x'≧3, W T x'≧3 is most preferred.

[0045] In another aspect, a battery, particularly a lithium-ion battery, comprising at least one separator described in the foregoing paragraph is described herein.

[0046] In another aspect, a battery separator includes a multilayer film or a microporous thin film having the same thickness, porosity, and dielectric breakdown uniformity better than that of a typical separator of Gurley.

[0047] In another aspect, a battery, particularly a lithium-ion battery, including at least one separator described in the foregoing paragraph is described herein.

[0048] In another aspect, a battery separator is described. The battery separator includes at least one multilayer microporous membrane or thin film having at least two regions or sub-layers each including at least two micro-layers, the multilayer film having or exhibiting at least one of the following: (a) a mixed intrusion (N) value greater than 380 N; (b) a mixed intrusion (N) value greater than 600 N; (c) a degree of bend of 1.8 or more; (d) an average dielectric breakdown value (V) 1 to 35% higher than that of a three-layer microporous thin film having the same thickness, Gurley, and / or porosity as the multilayer microporous thin film; (e) a minimum dielectric breakdown value (V) 3 to 20% higher than that of a three-layer microporous membrane or thin film having the same thickness, Gurley, and / or porosity as the multilayer microporous membrane; (f) having dielectric breakdown uniformity; (g) passing a nail penetration test; (h) having at least one micro-layer including PO, PP, and / or PE and an elastomer; (i) having at least one micro-layer including a siloxane; (j) having at least one micro-layer including PP and an elastomer; (k) having at least one micro-layer including a copolymer; (l) having at least one micro-layer including PP and a copolymer; (m) having at least two micro-layers including different resins or resin blends; (n) when one of the regions includes polypropylene in one or more of the micro-layers, when this region is tested according to the machine learning test described herein, at least one of the following is satisfied: W T x' ≧ - 5 or W T x' ≧ -3; (o) when one of the regions includes polypropylene in one or more of the micro-layers When including polypropylene, when this region is tested according to the dimensionality reduction technique known as PCA described herein, at least one of the following is satisfied: W T x'≥0, and W T x'≥3; (p) When one of the above regions contains polyethylene in one or more of the micro-layers, when this region is tested according to the machine learning test described herein, at least one of the following is satisfied: W T x'≥ -4 and W T x'≥ -2.654; (q) When one of the above regions contains polyethylene in one or more of the micro-layers, when this region is tested according to the machine learning test described herein, at least one of the following is satisfied: W T x' ≥1.3, and W T x'≥2; (r) One of the above regions contains PE, and also many Having a crystallinity that is 1 to 20% lower, as measured by DSC, than that of the PE-containing layer of a three-layer microporous membrane or thin film having the same thickness, Gurley, and / or porosity as the layer microporous thin film; (s) the microporous multilayer film or thin film has 30 to 100 micro-layers or more layers; (t) at least one of the micro-layers contains lithium stearate; (u) the multilayer microporous thin film exhibits a reduced MD or TD tear strength; (v) at least one of the micro-layers contains PE beads; (w) has a pin removal of less than 50 N; (x) exhibits a reduced contact with pins; (y) has a reduced MD or TD tear strength; (z) may be a precursor for at least one of lateral (TD) stretching, calendaring, and pore filling. In some embodiments, the microporous multilayer film exhibits one or more, two or more, three or more, four or more, five or more, six or more, seven or more, eight or more, nine or more, ten or more, eleven or more, twelve or more, thirteen or more, fourteen or more, fifteen or more, sixteen or more, seventeen or more, eighteen or more, nineteen or more, twenty or more, twenty-one or more, twenty-two or more, twenty-three or more, twenty-four or more, twenty-five or more, or 26 of the 26 options. The separator may include other properties. In some embodiments, the battery separator is coated on one or more of its surfaces and, in some embodiments, is not coated. In some embodiments, the coating is a ceramic coating.

[0049] In another aspect, a battery, particularly a lithium-ion battery, comprising at least one separator as described in the preceding paragraphs is described herein.

[0050] In another aspect, a method of forming an improved battery separator comprising a multilayer microporous membrane or thin film is described herein. The method includes co-extruding at least two layers and combining the at least two co-extruded layers with another layer or several In an embodiment, it at least includes a step of laminating with two other layers to form a multilayer microporous membrane. In some embodiments, at least 2, 3, 4, 5, 6, 7, 8, 9, or 10 layers are coextruded. In some embodiments, at least one of at least one other layer, or at least two of at least two other layers is a coextruded layer. In some embodiments, at least one of the other layers is a single-extruded layer. In an embodiment where at least two coextruded layers are laminated to two other layers, optionally, one of the two other layers is laminated to the first side of the at least two coextruded layers, and the second layer of the two other layers is laminated to the side of the at least two coextruded layers opposite to the first side. At least one of the two other layers may be a coextruded layer. In some embodiments, both of the two other layers are coextruded layers. In some embodiments, at least one of the at least two coextruded layers and the other layer include a polyolefin or a polyolefin blend. For example, these may include polyethylene or a polyethylene blend or polypropylene or a polypropylene blend. In some embodiments, at least one of the at least two coextruded layers includes polyethylene, and at least one or both of the other layers include polypropylene or a polyethylene blend. In some embodiments, at least one of the at least two coextruded layers includes polyethylene, and at least one or both of the other layers include polypropylene or a polypropylene blend. In some embodiments, each of the two other layers includes polyethylene or a polyethylene blend. In some embodiments, each of the two other layers includes polypropylene or a polypropylene blend. In some embodiments, one or both of the two other layers are coextruded layers coextruded with two or more, three or more, four or more, five or more, six or more, seven or more, eight or more, or nine or more other layers. When a layer is coextruded with nine other layers, the total number of coextruded layers is 10. In another aspect, a battery separator produced by the method described in the foregoing paragraph.

Brief Description of the Drawings

[0051]

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DETAILED DESCRIPTION OF THE INVENTION

[0052] The embodiments described herein can be more readily understood by reference to the following detailed description, examples, and figures. However, the elements, apparatus, and methods described herein are not limited to the specific embodiments presented in the detailed description, examples, and figures. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Many changes and modifications will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention.

[0053] Also, all ranges disclosed herein should be understood to encompass every sub-range subsumed therein. For example, a range described as "1.0 to 10.0" should be considered to include every sub-range starting with a minimum value of 1.0 or more and ending with a maximum value of 10.0 or less, such as 1.0 to 5.3, or 4.7 to 10.0, or 3.6 to 7.9.

[0054] All ranges disclosed herein must also be considered to include both ends of the range, unless otherwise explicitly stated. For example, ranges of "between 5 and 10", "from 5 to 10", or "5 - 10" should generally be considered to include both ends 5 and 10. It should be so considered.

[0055] Furthermore, when the phrase "up to" is used in conjunction with an amount or quantity, it should be understood that the amount is at least a detectable amount or quantity. For example, a material present in an amount "up to" a specified amount can be present in and include amounts from a detectable amount up to and including the specified amount.

[0056] The following are described herein: a microporous multilayer thin film or membrane; a battery separator comprising at least one of the microporous multilayer thin films or membranes; a battery, particularly a lithium ion battery, comprising at least one of the battery separators described herein; a device comprising the battery described herein; and a method of making a microporous multilayer thin film or membrane.

[0057] A multilayer (or multi-layer) microporous thin film or membrane exhibits improved properties, particularly when compared to past three-layer and multilayer microporous thin films having the same thickness, Gurley, and / or porosity. The improved properties of the thin film or membrane include, but are not limited to, improved puncture strength (gf) compared to prior tri-layer (or trilayer) and multilayer products, improved mixed intrusion average (N) compared to prior tri-layer and multilayer products, improved elongation (kgf / cm 2 ) compared to prior tri-layer and multilayer products, a faster shutdown speed (Ω-cm 2 ) compared to prior tri-layer and multilayer products, a higher average dielectric breakdown (DB) value (V) compared to prior tri-layer and multilayer products, a lower DB standard deviation (V) compared to prior tri-layer and multilayer products, a higher minimum DB value (V) compared to prior tri-layer and multilayer products, passing an industrial nail penetration test that prior tri-layer and multilayer microporous thin films did not pass, and improved cycle life compared to past tri-layer and multilayer products. It has also been found that the multilayer microporous thin films herein have a unique structure. This unique structure of these thin films accounts for many of the observed improved properties.

[0058] Battery separator The battery separator herein comprises, consists of, or consists essentially of one (i.e., one or more) multilayer film or multilayer microporous thin film, and optionally a coating layer on one or both sides of the film. The thin film itself, i.e., the thin film having no coating or any other additional components, exhibits the improved properties described above. The performance of the thin film can be improved by the addition of a coating or other additional components.

[0059] (1) Multilayer microporous thin film or membrane In some embodiments, the multilayer film or multilayer microporous thin film comprises 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 11 or more, 12 or more, 13 or more, 14 or more, 15 or more, 15 or more, 16 or more, 17 or more, 18 or more, 19 or more, 20 or more, 21 or more, 22 or more, 23 or more, 24 or more, 25 or more, 26 or more, 27 or more, 28 or more, 29 or more, 30 or more, 40 or more, 50 or more, 60 or more, 70 or more, 80 or more, 90 or more, or 100 or more layers. What is meant by the term "layer" includes single-extruded layers having a thickness of 2 to 20 microns. As will be understood by those skilled in the art, a single-extruded layer is a layer extruded by itself without any other accompaniments. Also, the layers of co-extruded two-layer, three-layer, or multilayer thin films are each considered to be "layers" for the purpose of determining whether a given battery separator is a multilayer battery separator. The number of layers in a co-extruded two-layer is 2, the number of layers in a co-extruded three-layer is 3, and the number of layers in a co-extruded multilayer thin film is 2 or more, preferably 3 or more. The exact number of layers of the two-layer, three-layer, or multilayer co-extruded thin film is determined by the die design and is not necessarily the materials co-extruded to form the co-extruded thin film. For example, the co-extruded two-, three- or multilayer thin film may be formed using the same material for each of the 2, 3, or 4 or more layers, and these layers are considered to be separate layers even if each is made of the same material. The exact number is similarly determined by the die design. The layers of the co-extruded two-, three- or multilayer thin film each have a thickness of 0.01 to 20 microns, preferably 0.1 to 5 microns, most preferably 0.1 to 3 microns, 0.1 to 2 microns, 0.1 to 1 micron, 0.01 to 0.9 micron, 0.01 to 0.8 micron, 0.01 to 0.7 micron, 0.01 to 0.6 micron, 0.01 to 0.5 micron, 0.01 to 0.4 micron, 0.01 to 0.3 micron, or 0.01 to 0.2 micron. These layers are micro-layers.

[0060] In some embodiments, the multilayer microporous thin film or multilayer microporous membrane disclosed herein comprises two or more, or preferably three or more, coextruded layers. A coextruded layer is a layer formed by a coextrusion process. At least two, preferably at least three, consecutive coextruded layers may be formed by the same or separate coextrusion processes. For example, at least two or at least three consecutive layers may be formed by the same coextrusion process, two or more layers may be coextruded by one process, two or more layers may be coextruded by separate processes, and two or more layers formed by one process may be laminated to two or more layers formed by separate processes such that four or more consecutive coextruded layers are combined. In some preferred embodiments, two or more, or preferably three or more, coextruded layers are formed by the same coextrusion process. For example, two or more, or preferably three or more, four or more, five or more, six or more, seven or more, eight or more, nine or more, ten or more, fifteen or more, twenty or more, twenty-five or more, thirty or more, thirty-five or more, forty or more, forty-five or more, fifty or more, fifty-five or more, or sixty or more coextruded layers may be formed by the same coextrusion process. In a further preferred embodiment, the extrusion process is carried out by extruding two or more polymer mixtures, which may be the same or different, without using a solvent. A preferred coextrusion process is a dry process, for example, the Celgard® dry process.

[0061] In some embodiments, the multilayer microporous thin film or multilayer film described herein forms a coextruded bilayer (2 coextruded layers), trilayer (3 coextruded layers), or multilayer (two or more, preferably three or more coextruded layers) thin film, and then the bilayer, trilayer, or multilayer thin film is fabricated by laminating it to at least one, but preferably two, other thin films. The at least one, but preferably two, other thin films may be nonwoven thin films, single-extruded thin films, or coextruded thin films. In a preferred embodiment, the other thin film is a coextruded thin film having the same number of coextruded layers as the coextruded bilayer, trilayer, or multilayer thin film. For example, when a coextruded trilayer thin film is formed, the others are also coextruded trilayers.

[0062] The lamination of a two-layer, three-layer, or multilayer coextruded film with at least one other single-extruded monolayer film or two-layer, three-layer, or multilayer film may involve the use of heat, pressure, or preferably both heat and pressure.

[0063] The polymers or copolymers that can be used in current battery separators are polymers or copolymers that are extrudable. Such polymers are typically referred to as thermoplastic polymers.

[0064] In some embodiments, one or more of the layers of the multilayer microporous film or multilayer film comprise a polymer or copolymer, or a polymer or copolymer blend, preferably a polyolefin or polyolefin blend. As understood by those skilled in the art, a polyolefin blend can be a blend of two or more different types of polyolefins, such as, a mixture of polyethylene and polypropylene, a blend of two or more of the same type of polyolefin where each polyolefin has different properties, such as ultra-high molecular weight polyolefin and low or ultra-low molecular weight polyolefin, or a mixture of a polyolefin and another type of polymer or copolymer, or may contain any additives.

[0065] Examples of polyolefins include, but are not limited to: polyethylene, polypropylene, polybutylene, polymethylpentene, copolymers thereof, and blends thereof. In some embodiments, the polyolefin can be an ultra-low molecular weight, low molecular weight, medium molecular weight, high molecular weight, or ultra-high molecular weight polyolefin, such as medium or high molecular weight polyethylene (PE) or polypropylene (PP). For example, an ultra-high molecular weight polyolefin can have a molecular weight of 450,000 (450k) or greater, such as 500k or greater, 650k or greater, 700k or greater, 800k or greater, 1,000,000 or greater, 2,000,000 or greater, 3,000,000 or greater, 4,000,000 or greater, 5,000,000 or greater, 6,000,000 or greater, and so on. A high molecular weight polyolefin can have a molecular weight in the range of 250k to 450k, such as 250k to 400k, 250k to 350k, or 250k to 300k. A medium molecular weight polyolefin can have a molecular weight in the range of 150 to 250k, such as 100k, 125k, 130k, 140k, 150k to 225k, 150k to 200k, 150k to 200k, and so on. A low molecular weight polyolefin can have a molecular weight in the range of 100k to 150k, such as 100k to 125k. An ultra-low molecular weight polyolefin can have a molecular weight of less than 100k. The above values are weight average molecular weights. In some embodiments, a higher molecular weight polyolefin may be used to increase the strength or other properties of the microporous multilayer film or battery, including those described herein. In some embodiments, a lower molecular weight polymer, such as a medium, low, or ultra-low molecular weight polymer, may be beneficial. For example, without wishing to be bound by any particular theory, it is believed that the crystallization behavior of a lower molecular weight polyolefin can result in a microporous thin multilayer film having smaller pores obtained from at least the MD stretching process that forms the pores.

[0066] Exemplary thermoplastic polymers, blends, mixtures or copolymers other than polyolefin polymers, blends or mixtures include, but are not limited to: polyacetal (or polyoxymethylene), polyamide, polyester, polysulfide, polyvinyl alcohol, polyvinyl ester, and polyvinylidene (such as PVDF, PVDF:HFP, PTFE, PEO, PVA, PAN, etc.). Examples of polyamides (nylons) include, but are not limited to: polyamide 6, polyamide 66, nylon 10,10, polyphthalamide (PPA), copolymers thereof, and blends thereof. Examples of polyesters include, but are not limited to: polyethylene terephthalate, polybutylene terephthalate, copolymers thereof, and blends thereof. Examples of polysulfides include, but are not limited to: polyphenyl sulfide, copolymers thereof, and blends thereof. Examples of polyvinyl alcohol include, but are not limited to: ethylene-vinyl alcohol, copolymers thereof, and blends thereof. Examples of polyvinyl esters include, but are not limited to: polyvinyl acetate, ethylene vinyl acetate, copolymers thereof, and blends thereof. Examples of polyvinylidene include, but are not limited to: fluorinated polyvinylidene (e.g., polyvinylidene chloride, polyvinylidene fluoride), copolymers thereof, and blends thereof. Various materials may be added to the polymer. These materials are added to modify or improve the performance or properties of the individual layer or the entire separator. Such materials include, but are not limited to: materials that may be added to lower the melting point of the polymer. Typically, a multilayer separator includes a layer designed to close pores at a predetermined temperature that blocks the flow of ions between the electrodes of the battery. This function is generally referred to as a shutdown.

[0067] In some embodiments, each layer of the multilayer microporous thin film or multilayer film comprises, consists of, or consists essentially of different polymers or copolymers or polymer or copolymer blends. In some embodiments, each layer comprises, consists of, or consists essentially of the same polymer or copolymer or polymer or copolymer blend. In some embodiments, alternating layers of the multilayer microporous thin film or multilayer film comprise, consist of, or consist essentially of the same polymer or copolymer or polymer or copolymer blend. In other embodiments, some of the layers of the multilayer film or microporous multilayer thin film comprise, consist of, or consist essentially of the same polymer or polymer blend, and some do not.

[0068] It may be preferred for each layer or micro-layer to comprise, consist of, or consist essentially of a polyolefin (PO), such as PP or PE or a PE+PP blend, mixture, copolymer, etc., but other polymers (PY), additives, drugs, materials, fillers, and / or particles (M), and / or the like may be added or used, and it is contemplated that these may form layers or micro-layers, such as PP+PY, PE+PY, PP+M, PE+M, PP+PE+PY, PE+PP+M, PP+PY+M, PE+PY+M, PP+PE+PY+M, or blends, mixtures, copolymers, and / or the like thereof.

[0069] Also, the same, similar, different, or different PP or PE or PE+PP polymers, homopolymers, copolymers, molecular weights, blends, mixtures, copolymers, etc. may be used. For example, the same, similar, different, or different molecular weight PP, PE, and / or PP+PE polymers, homopolymers, copolymers, multimers, blends, mixtures, and / or the like may be used in each layer. Thus, the structure may include various combinations and sub - combinations of PP, PE, PP+PE, PP1, PP2, PP3, PE1, PE2, PE3, PP1+PP2, PE1+PE2, PP1+PP2+PP3, PE1+PE2+PE3, PP1+PP2+PE, PP+PE1+PE2, PP1 / PP2, PP1 / PP2 / PP1, PE1 / PE2, PE1 / PE2 / PP1, PE1 / PE2 / PE3, PP1+PE / PP2, or other combinations or structures.

[0070] In some embodiments, one or more additives are added to the outermost layer of the multilayer microporous thin film or multilayer film to improve its properties or the properties of the battery separator or the battery including it. The outermost layer may include PE, PP, or PE+PP in addition to the additive. For example, to improve pin removal (i.e., to reduce the coefficient of friction of the thin film or membrane), additives such as lithium stearate, calcium stearate PE beads, siloxane, and polysiloxane may be added.

[0071] In addition, a specific polymer, copolymer, or polymer or copolymer blend is used in the outermost layer of the multilayer microporous thin film or multilayer film to improve its properties or the properties of the battery separator or the battery including it. For example, by adding an ultra - high molecular weight polymer or copolymer in the outermost layer, the puncture strength can be improved.

[0072] In a further embodiment, an additive for improving oxidation resistance may be added to the outermost layer of the multilayer microporous thin film or membrane. The additive may be an organic or inorganic additive, or a polymeric or non-polymeric additive.

[0073] In some embodiments, the outermost layer of the multilayer thin film or membrane may comprise, consist of, or consist essentially of polyethylene, polypropylene, or a mixture thereof.

[0074] In some embodiments, the microporous multilayer thin film or membrane may include three or more different regions or sub-membrane areas. In a preferred embodiment, one or more of the regions or sub-membrane areas may comprise, consist of, or consist essentially of two or more layers which may or may not be coextruded layers. In some preferred embodiments, the two or more layers are coextruded layers. In some embodiments, there is a lamination barrier between a region or sub-membrane area and an adjacent region or sub-membrane area. The lamination barrier is formed when two surfaces, e.g., the two surfaces of different thin films or layers, are laminated together using heat, pressure, but preferably heat and pressure. In some embodiments, the sub-membrane area has the following non-limiting structures: PP, PE, PP / PP, PP / PE, PE / PP, PE / PE, PP / PP / PP, PP / PP / PE, PP / PE / PE, PP / PE / PP, PE / PP / PE, PE / PE / PP, PP / PP / PP / PP, PP / PE / PE / PP, PE / PP / PP / PE, PP / PE / PP / PP, PE / PE / PP / PP, PE / PP / PE / PP, PP / PE / PE / PE / PP, PE / PP / PP / PP / PE, PP / PP / PE / PP / PP, PE / PE / PP / PP / PE / PE, PP / PE / PP / PE / PP, PP / PP / PE / PE / PP / PP, PE / PE / PP / PP / PE / PE, PE / PP / PE / PP / PE / PP, PP / PE / PP / PE / PP / PE, PP / PP / PP / PE / PP / PP / PP, PE / PE / PE / PP / PE / PE / PE, PP / PE / PP / PE / PP / PE / PP, PE / PP / PE / PP / PE / PP / PE, PE / PP / PE / PP / PE / PP / PE / PP, PP / PE / PP / PE / PP / PE / PP / PE, PP / PP / PE / PE / PP / PP / PE / PE, PP / PE / PE / PE / PE / PE / PE / PP, PE / PP / PP / PP / PP / PP / PP / PE, PP / PP / PE / PE / PEPE / PP / PP, PP / PP / PP / PP / PE / PE / PE / PE, PP / PP / PP / PP / PE / PP / PP / PP / PP, PE / PE / PE / PE / PP / PE / PE / PE / PE, PP / PE / PP / PE / PP / PE / PP / PE / PP,PE / PP / PE / PP / PE / PP / PE / PP / PE, PE / PE / PE / PE / PE / PP / PP / PP / PP, PP / PP / PP / PP / PP / PE / PE / PE / PE, PP / PP / PP / PP / PP / PE / PE / PE / PE / PE, PE / PE / PE / PE / PE / PP / PP / PP / PP / PP, PP / PE / PP / PE / PP / PE / PP / PE / PP / PE, PE / PP / PE / PP / PE / PP / PE / PP / PE / PP, PE / PP / PP / PP / PP / PP / PP / PP / PP / PP / PE, PP / PE / PE / PE / PE / PE / PE / PE / PE / PE / PP, PP / PP / PE / PE / PP / PP / PE / PE / PP / PP, PE / PE / PP / PP / PP / PP / PP / PP / PP / PE / PE, PP / PP / PP / PE / PE / PP / PP / PP / PP / PE, PE / PE / PE / PP / PP / PE / PE / PE / PP / PP. In this specification, PE represents a layer or micro-layer of a region or sub-membrane area that contains, consists of, or consists essentially of PE, such as a co-extruded layer or micro-layer. In this specification, PP represents a layer or micro-layer of a region or sub-membrane area that contains, consists of, or consists essentially of PP, such as a co-extruded layer or micro-layer. The PE or PP of different layers or micro-layers may be the same or different. Similar variations including up to 50 layers or micro-layers, particularly co-extruded layers or micro-layers, per region or sub-membrane area can be formed by a suitable extrusion die.,

[0075] In one preferred embodiment, the co-extrusion precursor may have structures such as (PP1 / PP2 / PP3), (PP3 / PP2 / PP1), (PP3 / PP3 / PP2 / PP1 / PP1), (PP3 / PP3 / PP2 / PP2 / PP1 / PP1), (PP3 / PP3 / PP3 / PP2 / PP2 / PP2 / PP1 / PP1 / PP1), etc.

[0076] PP1 is a homopolymer PP and any It is made of additives including an anti-slip additive or an anti-blocking additive and changes the surface friction coefficient. PP2 may be made of the same or different PP homopolymers as PP1 and copolymers of PP. The PP copolymer may be any propylene-ethylene or ethylene-propylene random copolymer, block copolymer, or elastomer. PP3 may be made of the same or different homopolymer PP as PP1 and PP2, and also includes an additive for changing the surface friction coefficient, which may be the same as or different from that used in PP1.

[0077] In other preferred embodiments, the coextrusion precursor may have structures such as (PP1 / PP2 / PP3), (PP3 / PP2 / PP1), (PP3 / PP3 / PP2 / PP1 / PP1), (PP3 / PP3 / PP2 / PP2 / PP1 / PP1), (PP3 / PP3 / PP3 / PP2 / PP2 / PP2 / PP1 / PP1 / PP1). PP1 may be any polypropylene blend. PP2 may be made of any PP block copolymer including those described herein. PP3 may be made of the same or different PP-block copolymer as that used in PP2.

[0078] The regions or sub-membrane areas may be arranged in any order to form a microporous multilayer film or a microporous multilayer thin film. For example, the microporous multilayer film or the microporous multilayer thin film may have the following non-limiting structures: (PP / PP)(PE / PE) / (PP / PP); (PE / PE)(PP / PP)(PE / PE); (PP / PE)(PP / PE)(PP / PE); (PP / PE)(PE / PP)(PE / PP); (PP / PP / PP)(PE / PE / PE)(PP / PP / PP); (PE / PE / PE)(PP / PP / PP)(PE / PE / PE); (PP / PE / PP)(PE / PP / PE)(PP / PE / PP); (PP / PP / PE)(PE / PE / PE)(PE / PP / PP); (PE / PE / PP)(PP / PP / PP)(PP / PE / PE); (PE / PP / PE) / (PP / PE / PP)(PE / PP / PE); (PP / PE / PP)(PE / PP / PE)(PP / PE / PP); (PP / PE / PP)(PP / PE / PP)(PP / PE / PP); (PP / PP / PP)(PP / PP / PP)(PP / PP / PP); (PE / PE / PE)(PE / PE / PE)(PE / PE / PE); (PE / PE / PE)(PP)(PE / PE / PE); (PP / PP / PP)(PE)(PP / PP / PP); (PE / PE / PE)(PP / PP)(PE / PE / PE); (PP / PP / PP)(PE / PE)(PP / PP / PP); (PE / PP / PE)(PP)(PE / PP / PE); (PP / PE / PP)(PE)(PP / PE / PP); (PE / PP / PE)(PP / PP)(PE / PP / PE); (PP / PE / PP)(PE / PE)(PP / PE / PP); (PP / PP / PP / PP)(PE)(PP / PP / PP / PP); (PE / PE / PE / PE)(PP)(PE / PE / PE / PE); (PP / PP / PP / PP / PP)(PE)(PP / PP / PP / PP / PP); (PE / PE / PE / PE / PE)(PP / PP)(PE / PE / PE / PE / PE); (PP / PP / PP / PP / PP)(PE / PE / PE / PE / PE)(PP / PP / PP / PP / PP); (PE / PE / PE / PE / PE / PE)(PP / PP / PP / PP / PP)(PE / PE / PE / PE / PE);(PP / PE / PP / PE / PP)(PE / PP / PE / PP / PE)(PP / PE / PP / PE / PP);(PE / PP / PE / PP / PE)(PP / PE / PP / PE / PP)(PE / PP / PE / PP / PE). The above modification examples can be used to form a microporous multilayer thin film or multilayer film having up to 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, or 200 layers or microlayers.;

[0079] The thickness of the microporous multilayer thin film or multilayer film is not very limited, but preferably less than 50 microns, less than 40 microns, less than 30 microns, less than 25 microns, less than 20 microns, less than 19 microns, less than 18 microns, less than 17 microns, less than 16 microns , less than 15 microns, less than 14 microns, less than 13 microns, less than 12 microns, less than 11 microns, less than 10 microns, less than 9 microns, less than 8 microns, less than 7 microns, less than 6 microns, or less than 5 microns. This is the thickness of the multilayer thin film or film before any coating or treatment is applied.

[0080] Microporous, as used herein, means that the average pore diameter of the thin film, film, or coating is 2 microns or less, preferably 1 micron or less, 0.9 micron or less, 0.8 micron or less, 0.7 micron or less, 0.6 micron or less, 0.5 micron or less, 0.4 micron or less, 0.3 micron or less, 0.2 micron or less, preferably 0.1 micron or less, 0.09 micron or less, 0.08 micron or less, 0.07 micron or less, 0.06 micron or less, 0.05 micron or less, 0.04 micron or less, 0.03 micron or less, 0.02 micron or less, or 0.01 micron or less. In a preferred embodiment, the pores can be formed, for example, by performing a stretching process in a precursor thin film as done in the Celgard® dry process.

[0081] In some preferred embodiments, the multilayer microporous thin film or membrane comprises, consists of, or consists essentially of sub - films or regions that contain PE, which are microporous and have an average pore diameter between 0.03 and 0.1, preferably between 0.05 and 0.09, 0.05 and 0.08, 0.05 and 0.07, or 0.05 and 0.06.

[0082] In other preferred embodiments, the multilayer microporous thin film or membrane comprises, consists of, or consists essentially of sub - films or regions that contain PP, which are microporous and have an average pore diameter between 0.02 and 0.06, preferably between 0.03 and 0.05, more preferably between 0.04 and 0.05 or 0.03 and 0.04.

[0083] In some other preferred embodiments, the multilayer microporous thin film or membrane comprises, consists of, or consists essentially of sub - films or regions that contain PP, or comprises, consists of, or consists essentially of sub - films or regions that contain PE, and the average pore diameter of the PP sub - film or region is smaller than that of the PE sub - film or region.

[0084] The Gurley of the microporous multilayer thin film or membrane is not highly limited and may have any Gurley that is acceptable for use as a battery separator. In some embodiments, the microporous multilayer thin film or membrane described herein has a JIS Gurley (s / 100cc) of 150 or more, 160 or more, 170 or more, 180 or more, 190 or more, 200 or more, 210 or more, 220 or more, 230 or more, 240 or more, 250 or more, 260 or more, 270 or more, 280 or more, 290 or more, 300 or more, 310 or more, 320 or more, 330 or more, 340 or more, or 350 or more.

[0085] The porosity of the microporous multilayer thin film is not very limited. For example, any porosity that can form an acceptable battery separator is acceptable. In some embodiments, the porosity of the thin film or membrane may be 10-60%, 20-60%, 30-60%, or 40-60%.

[0086] When not coated, the microporous multilayer thin film or membrane may have a puncture strength as high as 290 gf or more, 300 gf or more, 310 gf or more, 320 gf or more, 330 gf or more, 340 gf or more, 350 gf or more, or 400 gf or more.

[0087] The microporous multilayer thin film or membrane may have any average dielectric breakdown that is consistent with the goals described herein. In some embodiments, the average dielectric breakdown value is improved or higher than that of a three-layer microporous thin film having at least one of the same thickness, Gurley, and porosity. For example, it may be 1-35% higher, 5-35% higher, 10-35% higher, 15-35% higher, 20-35% higher, 25-35% higher, or 30-35% higher than that of a three-layer microporous thin film having the same thickness, Gurley, and / or porosity.

[0088] The minimum dielectric breakdown value of the microporous multilayer thin film or membrane is not very limited. In some embodiments, the minimum value may be improved (or higher) than that of a three-layer microporous thin film having the same thickness, Gurley, and / or porosity. For example, the minimum dielectric breakdown value may be 3-20% higher, 5-15% higher, 10-15% higher, 5-10% higher, 3-10% higher, 3-15% higher, 15-20% higher, 10-20% higher, or 5-20% higher than that of a three-layer microporous thin film having the same thickness, Gurley, and / or porosity.

[0089] The standard deviation of the dielectric breakdown value is also not very limited. In some embodiments, the standard deviation is improved (or lower) compared to a three-layer microporous thin film having the same thickness, Gurley, and / or porosity. For example, the standard deviation may be 10 - 55% lower, 10 - 50% lower, 10 - 45% lower, 10 - 40% lower, 10 - 35% lower, 10 - 30% lower, 10 - 25% lower, 10 - 20% lower, or 10 - 15% lower.

[0090] Higher average DB value, minimum DB value, and lower DB standard deviation indicate that the thin film can be used to provide a safer battery separator and battery. Dielectric breakdown is the voltage value at which current begins to flow across an insulator. A higher value clearly indicates a separator that can withstand a higher voltage. A higher minimum value is also important because the battery separator is just as safe at its weakest point. Also, with a higher average value, if one point in the thin film breaks down at a lower value, it is not good. The lower standard deviation of the DB value in the multilayer microporous thin films described herein indicates consistency in the safety of the microporous multilayer thin films described herein.

[0091] The mixed intrusion average (N) of the microporous multilayer thin films or film mixtures described herein is also not very limited. For example, the mixed intrusion value may be 380N or more, 390N or more, 400N or more, 410N or more, 420N or more, 440N or more, 450N or more, 460N or more, 470N or more, 480N or more, 500N or more, 510N or more, 520N or more, 550N or more, 560N or more, 580N or more, 600N or more, 620N or more, 640N or more, 660N or more, 680N or more, 690N or more, 700N or more, 710N or more, 720N or more, 740N or more, 750N or more, 760N or more.

[0092] The MD shrinkage rate of the multilayer microporous thin film or membrane described in this specification is not highly limited, but is preferably lower than those of the previous three-layer microporous thin films. For example, the MD shrinkage rate (%) at 105 °C is less than 3%, preferably less than 2.5%, more preferably less than 2% or less than 1.5%, and most preferably less than 1%.

[0093] The MD tensile strength of the microporous multilayer thin film is not highly limited, but is preferably high. For example, 1800 kgf / cm 2 more than, 2000 kgf / cm 2 more than, 2100 kgf / cm 2 more than, 2200 kgf / cm 2 more than, 2250 kgf / cm 2 more than, 2300 kgf / cm 2 more than, 2400 kgf / cm 2 more than, or 2500 kgf / cm 2 more than.

[0094] The MD elongation of the microporous multilayer thin film is not highly limited. For example, in some embodiments, it is more than 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. In some embodiments, it is more than 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%.

[0095] The TD tensile strength of the microporous multilayer thin film is not highly limited. For example, in some embodiments, the TD tensile strength is 120 kgf / cm 2 or more, 125 kgf / cm 2 or more, 130 kgf / cm 2 or more, 135 kgf / cm 2 or more, 140 kgf / cm 2 or more, 145 kgf / cm 2 or more, 150 kgf / cm 2 or more, 155 kgf / cm 2 or more, 160 kgf / cm 2 or more, 165 kgf / cm 2 or more, 170 kgf / cm 2 or more, 175 kgf / cm2 Above, 180 kgf / cm 2 Above, 185 kgf / cm 2 Above, or 190 kgf / cm 2 Above, or 195 kgf / cm 2 Above.

[0096] The TD elongation of the microporous multilayer film is not very limited. For example, it may be over 500%, over 550%, over 600%, over 650%, over 700%, over 750%, over 800%, over 850%, over 900%, over 950%, or over 1000%.

[0097] The shutdown temperature of the microporous multilayer film is not very limited, but preferably 120 °C or higher, 130 °C or higher, 140 °C or higher, 150 °C or higher, 160 °C or higher, 170 °C or higher, 180 °C or higher, 190 °C or higher, or 200 °C or higher. The shutdown rate of the microporous multilayer film is not very limited, but preferably 6,000 Ω-cm 2 Above, 7,000 Ω-cm 2 Above, 8,000 Ω-cm 2 Above, 9,000 Ω-cm 2 Above, 10,000 Ω-cm 2 Above, 11,000 Ω-cm 2 Above, 12,000 Ω-cm 2 Above, 13,000 Ω-cm 2 Above, 14,000 Ω-cm 2 Above, 15,000 Ω-cm 2 Above, 16,000 Ω-cm 2 Above, 17,000 Ω-cm 2 Above, 18,000 Ω-cm 2 Above, 19,000 Ω-cm 2 Above or 20,000 Ω-cm 2 Above.

[0098] A higher shutdown rate also indicates a safer battery separator. The faster the battery can shut down, the higher the ability to prevent thermal runaway.

[0099] In some embodiments, the microporous multilayer films or thin films described herein can surprisingly exhibit increased strength performance as defined by a reduced degree of tearing or a reduced tendency to tear, particularly when compared to known battery separators of the same (or greater) thickness, and in particular when compared to known dry process battery separators of the same (or greater) thickness. The improvement in tearing or degree of tearing can be quantified by the test method disclosed herein as the Composite Tear Index (CSI), and the novel or improved separator formed from the films or thin films described herein can have an improved CSI.

[0100] Regarding the structural characteristics of the microporous multilayer thin films and films described herein, in some embodiments, the degree of curvature of the thin film is greater than 1.6, greater than 1.7, 1.8, greater than 1.9, greater than 2.0, greater than 2.1, or greater than 2.2. Without wishing to be bound by any particular theory, the observed degree of curvature values, particularly values greater than 2.0, 2.1, or 2.2, are thought to be responsible for the increased puncture strength and average value of mixed intrusion disclosed herein. A more curved thin film is also said to be safer when used as a battery separator for a lithium-ion battery.

[0101] The MacMullin number of the microporous multilayer thin film or film described herein is greater than 5.0, greater than 5.5, greater than 6.0, greater than 6.5, greater than 7.0, greater than 7.5, greater than 8.0, greater than 8.5, greater than 9.0, greater than 9.5, greater than 10.0, or greater than 10.5.

[0102] In some embodiments, the electrical resistance of the microporous multilayer thin film or film is greater than 0.9, greater than 1.0, greater than 1.1, greater than 1.2, greater than 1.3, greater than 1.4, greater than 1.5, 1.6, or greater than 1.7.

[0103] The crystallinity of the microporous multilayer thin films described herein has been found to be different from that of previous multilayer and trilayer thin films. For example, in some embodiments where the microporous multilayer thin film comprises: (1) a first region comprising two or more layers; (2) a second region comprising two or more layers on a first surface of the first region; and (3) a third region comprising two or more layers on a surface opposite the first surface of the first region, at least one of the first, second or third regions comprises PE, and when the trilayer microporous thin film has the same thickness as the multilayer microporous thin film, it has a lower crystallinity as measured by DSC than the PE-containing layer of the trilayer microporous thin film. For example, the crystallinity may be 1 to 20%, 1 to 19%, 1 to 18%, 1 to 17%, 1 to 16%, 1 to 15%, 1 to 14%, 1 to 13%, 1 to 12%, 1 to 11%, 1 to 10%, 1 to 9%, 1 to 8%, 1 to 7%, 1 to 6%, 1 to 5%, 1 to 4%, 1 to 3%, or 1 to 2% lower than the PE-containing layer of the trilayer microporous thin film when the trilayer microporous thin film has the same thickness as the multilayer microporous thin film.

[0104] Another structural difference between the multilayer microporous thin films described herein and the prior three-layer and multilayer thin films can be seen using a scanning electron microscope. For example, see FIGS. 25-31. For example, as shown in FIGS. 25-31, the multilayer microporous thin film or membrane can include a first region including at least two or more layers and a second layer including at least one layer. The first region can include mostly discontinuous amorphous regions when viewed in the z-direction of the thin film using SEM. What the term "mostly" means is that although not necessarily all, most of the amorphous regions in the first layer are discontinuous. This can mean that at least 50%, more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, more than 95%, more than 99%, or 100% of the amorphous regions in the first layer are continuous. A "discontinuous amorphous region" means that when a sample of the first layer is analyzed, for example, by SEM, the path of the amorphous region is interrupted or blocked by crystalline (lamellar) regions along the entire thickness direction of the first layer. Discontinuous means that the path of the amorphous region is interrupted or blocked by crystalline (lamellar) regions along the entire thickness direction of the first layer. The path of the amorphous region does not go around the crystalline (lamellar) regions. Instead, the crystalline (lamellar) regions completely divide the path of the amorphous region along the entire thickness direction of the first layer. The path of the amorphous region can be linear or circuitous. An example of the difference between a discontinuous amorphous region and a continuous amorphous region can be seen by comparing the SEM of the polyethylene layer of COM EX4 with the SEM of the polyethylene layer RO397 in FIG. 29. Discontinuous can also mean that the amorphous region is non-cylindrical, non-vertically continuous, or non-strut-like along the thickness of the layer. In some preferred embodiments, the first region, which is mostly a discontinuous amorphous region, can include, consist of, or consist essentially of polypropylene in some or all of the layers in the region. In some other embodiments, the second region includes two or more layers, and the amorphous area of the region of the thin film or membrane has a maximum width of 0.85 microns, 0.8 microns, 0.75 microns, 0.70 microns, 0.65 microns, or 0.6 microns.For example, this can be understood by comparing COM EX4 with R037 in FIG. 30. In some preferred embodiments, the second region may comprise, consist of, or consist essentially of polyethylene in some or all of the layers in the region.

[0105] (2) Optional coating In some embodiments, one or more coating layers may be applied to one or both sides of a microporous membrane or a thin film to form a battery separator. In some embodiments, one or more of the coatings may comprise, consist of, or consist essentially of a polymeric binder and organic and / or inorganic particles, and may be a ceramic coating. In some embodiments, only the ceramic coating is applied to one or both sides of the microporous membrane or thin film. In other embodiments, different coatings may be applied to the microporous membrane or thin film before or after the application of the ceramic coating. Further different coatings may also be applied to one or both sides of the above-mentioned membrane or thin film. In some embodiments, different polymeric coating layers may comprise, consist of, or consist essentially of at least one of polyvinylidene difluoride (PVdF) or polycarbonate (PC). In some embodiments, the thickness of the coating layer is less than about 12 μm, optionally less than 10 μm, optionally less than 9 μm, optionally less than 8 μm, optionally less than 7 μm, optionally less than 5 μm. In at least certain selected embodiments, the coating layer is less than 4 μm, less than 2 μm, or less than 1 μm.

[0106] The coating method is not very limited, and the coating layers described herein can be coated on the porous structure by at least one of the following coating methods: extrusion coating, roll coating, gravure coating, printing, knife coating, air knife coating, spray coating, dip coating, or curtain coating. The coating process can be carried out at room temperature or at a high temperature.

[0107] The coating method is not very limited, and the coating layers described herein can be coated on the porous structure by at least one of the following coating methods: extrusion coating, roll coating, gravure coating, printing, knife coating, air knife coating, spray coating, dip coating, or curtain coating. The coating process can be carried out at room temperature or at a high temperature.

[0108] The coating layer may be any one of non-porous, nanoporous, microporous, mesoporous, or macroporous. The coating layer may have a JIS Gurley of 700 or less, optionally 600 or less, 500 or less, 400 or less, 300 or less, 200 or less, or 100 or less.

[0109] One or more layers, treatments, materials, or coatings (CT) and / or nets, meshes, mats, woven or non-woven fabrics (NW) may be added to one or both sides of, or within, the multilayer thin films or membranes (M) described herein, including CT / M, CT / M / CT, NW / M, NW / M / NW, CT / M / NW, CT / NW / M / NW / CT, CT / M / NW / CT, etc.

[0110] Method The method for forming the multilayer microporous thin films or membranes described herein is not very limited and may be a dry process, preferably a CELGARD® dry-stretching process, a dry process such as BNOPP, or a wet process using a solvent or oil.

[0111] The method for forming the multilayer microporous thin films or membranes described herein includes at least the following steps: (1) co-extruding two or more polymer mixtures, which may be the same or different, to form a co-extruded thin film having two or more layers or micro-layers, as described above herein; (2) laminating the co-extruded thin film to at least one other single-extruded thin film, co-extruded thin film, or non-woven fabric, and in some preferred embodiments, the co-extruded thin film is laminated to two other co-extruded thin films having two or more micro-layers; (3) optionally, one or more additional steps.

[0112] (1) Co-extrusion step Coextrusion is not so limited. Exemplary coextrusion processes are shown in FIG. 7, and coextrusion dies are shown in FIG. 8. In some embodiments, the coextrusion die is used in conjunction with one or more extruders that supply the die. Typically, there is one extruder for each desired layer or microlayer of the ultimately formed coextruded film. For example, when the desired coextruded film has three microlayers, three extruders are used with the coextrusion die. In at least one embodiment, the film of the present invention can be composed of many microlayers or nanolayers in which the final product can contain 50 or more individual microlayers or nanolayers. In at least some embodiments, the technology of microlayers or nanolayers can be induced by a preliminary encapsulation feed block before entering the cast or blown film die.

[0113] In some preferred embodiments, coextrusion is a bubble coextrusion method, and the blow-up ratio can vary from 0.5 to 2.0, preferably from 0.7 to 1.8, and most preferably from 0.9 to 1.5. After coextrusion using this blow-up ratio, the thin film may be stretched in the MD direction, or stretched in the MD direction and then in the TD direction (with or without MD relaxation), or stretched simultaneously in the MD and TD directions. The thin film may optionally be calendered to further control the porosity.

[0114] The benefits of coextrusion include, but are not limited to, an increase in the number of layers (interfaces), and while not wishing to be bound by any particular theory, it is said to improve puncture strength. Also, coextrusion, while not wishing to be bound by any particular theory, is said to result in an improvement in DB. Specifically, the improvement in DB may be related to the reduced PP pore size observed when the coextrusion process is used. Also, coextrusion allows for a wide range of material options by incorporating blends into the micro-layers. Coextrusion also enables the formation of thin three-layer or multi-layer films (coextruded films). For example, a three-layer coextruded film having a thickness of 8 or 10 microns or less can be formed. Coextrusion allows for higher MD elongation and different pore structures (less PP, more PE). Coextrusion can be combined with lamination to create the desired multi-layer structure of the present invention. For example, the structure is as formed in the examples.

[0115] The minimum achievable thickness is determined by the extrusion process. In some examples, the thinnest PP micro-layer can be about 0.19 mils (sub-layer of about 4.83um), PE can be about 0.17 mils (sub-layer is about 4.32um), and for each of the three micro-layers of PP and PE, they can be 0.19 mils or 0.17 mils respectively. For an example of a 21-layer structure, according to the inventors, it can have a total extrusion thickness of 1.31 mils (33um), about 1.14 mils of PP (or 0.57 mils on each side) and 0.17 mils of PE. The inventors may be able to produce a 21-layer product of 30um or less with this configuration.

[0116] (2) Lamination The lamination is not very limited and includes bringing the surface of the coextruded film together with the surface of at least one other film and using heat, pressure, and / or heat and pressure to fix such two surfaces to each other. By using heat, for example, the viscosity of the surface of either or both of the coextruded film and at least one other film is increased to make the lamination easier, whereby the two surfaces are made sticky and can be adhered together better.

[0117] In some preferred embodiments, the laminate formed by laminating the coextruded film to at least one other film serves as a precursor for subsequent MD and / or TD stretching steps with or without relaxation. In some embodiments, the coextruded film is stretched prior to lamination.

[0118] (3) Further steps The further steps may include, consist of, or consist essentially of MD, TD, or sequential or simultaneous MD and TD stretching steps. The stretching step may be performed before or after the lamination step. The stretching may be performed with or without MD and / or TD relaxation. The co-owned U.S. Patent Application Publication No. US2017 / 0084898A1, which was published on March 23, 2017 and is co-pending, is hereby incorporated herein by reference in its entirety.

[0119] Additional further processes may include calendering. For example, in some embodiments, the calendering process may be carried out as a means of reducing thickness, which also reduces pore size and / or porosity and / or further improves the transverse direction (TD) tensile strength and / or puncture strength of the porous biaxially stretched film precursor. Calendering can also improve strength, wettability, and / or uniformity, and can reduce surface layer defects that would otherwise be incorporated during the manufacturing process, for example, during the MD and TD stretching processes. The calendered thin film or membrane may have improved coating ability (using a smooth calender roll). Additionally, the use of a textured calender roll can aid in improved film adhesion to the coating on the thin film or membrane.

[0120] Calendering can be cold (below room temperature), ambient (room temperature), or hot (e.g., 90 °C) and can involve the application of pressure or the application of heat and pressure to controllably reduce the thickness of the membrane or thin film. Calendering can be in one or more steps, such as low-pressure calendering followed by higher-pressure calendering, cold calendering followed by hot calendering, and / or the like. Additionally, the calendering process can use at least one of heat, pressure, and speed to densify the thermosensitive material. Additionally, the calendering process can selectively densify the thermosensitive material using uniform or non-uniform heat, pressure, and / or speed, (e.g., the use of smooth rolls, rough rolls, patterned rolls, micro-patterned rolls, nano-patterned rolls, speed changes, temperature changes, pressure changes, humidity changes, double-roll processes, multiple-roll processes, or combinations thereof) to impart a uniform or non-uniform calendered state, resulting in improved, desired, or unique structures, features, and / or performance, and can produce or control the resulting structures, features, and / or performance, and / or the like.

[0121] Another additional step may include pore filling. The pore filling step is not so limited and may be carried out in any way consistent with the goals described herein. For example, in some embodiments, the pores may be partially or completely coated, treated, or filled by a pore filling composition, material, polymer, gel polymer, layer, or physical vapor deposition (PVD). Preferably, the pore filling composition coats 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 95% or more, etc. of the surface area of the pores. The pore filling composition may comprise, consist of, or consist essentially of a polymer and a solvent. The solvent may be any suitable solvent useful for forming a composition for coating or filling the pores, including organic solvents such as octane, water, or a mixture of organic solvents and water. The polymer may be any suitable polymer, including acrylate polymers or polyolefins including low molecular weight polyolefins. The concentration of the polymer in the pore filling composition is not so limited as long as the viscosity of the pore filling composition enables it to coat the walls of the pores of any of the porous biaxially stretched precursor membranes disclosed herein, but may be between 1% and 30%, between 2% and 25%, between 3% and 20%, between 4% and 15%, between 5% and 10%, etc. Pore filling increases either or both of the machine direction (MD) and transverse direction (TD) tensile forces.

[0122] Composite material, vehicle, or device A composite material comprising the battery separator described above herein and one or more electrodes provided in direct contact therewith, such as an anode, a cathode, or an anode and a cathode. The type of electrode is not so limited. For example, the electrode may be suitable for use in a lithium-ion secondary battery.

[0123] A suitable anode can have an energy capacity of 372 mAh / g or more, preferably ≥ 700 mAh / g, and most preferably ≥ 1000 mAh / g. The anode is not simply composed of a lithium metal foil or a lithium alloy foil (e.g., lithium aluminum alloy), or a mixture of lithium metal and / or lithium alloy with materials such as carbon (e.g., coke, graphite), nickel, and copper. The anode is not merely made of an intercalation compound containing lithium or an insertion compound containing lithium.

[0124] A suitable cathode can be any cathode that is compatible with the anode and may include an intercalation compound, an insertion compound, or an electrochemically active polymer. Suitable interlayer materials include, for example, MoS2, FeS2, MnO2, TiS2, NbSe3, LiCoO2, LiNiO2, LiMn2O4, V6O 13 , V2O5, and CuCl2. Suitable polymers include, for example, polyacetylene, polypyrrole, polyaniline, and polythiophene.

[0125] Any of the separators described above herein can be incorporated into any vehicle that is fully or partially battery-powered, such as an electric vehicle, or a device, such as a mobile phone or a laptop computer.

[0126] The various embodiments of the present invention are described in connection with the achievement of the various objects of the present invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Many changes and modifications will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention.

Examples

[0127] Preparation of Examples With reference mainly to Examples 1 to 10 and Comparative Examples 1 to 5 below, the (multilayer) product of the present invention was prepared and compared with a comparative (three-layer) product. The multilayer product is formed by the method described herein and includes a step of co-extruding three separate thin films each including three co-extruded layers, and a step of laminating the three thin films together. The three-layer product was formed by forming three separate extruded single-layer thin films and laminating the single layers together.

[0128] The composition of the micro-layers of the prepared product of the present invention is as follows:

[0129] Example 1 (EX1) - (PP / PP / PP)(PE / PE / PE)(PP / PP / PP) - All PP layers are made of homopolymer PP with a density = 0.90 g / cm 3 , and a melt flow rate (MFR) in the range of 0.5 MFR to 2 MFR. All PE layers are a blend of 95% high-density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and 5% mLLDPE, with a density range of 0.955 to 0.966 g / cm 3 .

[0130] Example 2 (EX2) - (PP1 / PP2 / PP1)(PE1 / PE2 / PE3)(PP1 / PP2 / PP1) - PP1 is homopolymer PP. PP2 is a homopolymer polypropylene having a higher MFR than PP1. PE1 is high-density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C. PE2 is ultra-high-density polyethylene. PE3 is a blend of 95% high-density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and 5% 3 mLLDPE, with a density range of 0.955 to 0.966 g / cm .

[0131] Example 3 (EX3) - (PP / PP / PP)(PE1 / PE2 / PE1)(PP / PP / PP) - The PP layers are made of homopolymer PP, with a density = 0.90 g / cm 3 , and a melt flow rate (MFR) in the range of 0.5 MFR to 2 MFR. PE1 is made of high-density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C. PE2 is made of ultra-high molecular weight polyethylene.

[0132] Example 4 (EX4) - (PP / PP / PP)(PE / PE / PE)(PP / PP / PP) - All PP layers are made of homopolymer PP, with a density = 0.90 g / cm 3 , and a MFR in the range of 0.5 MFR to 2 MFR. All PE layers are made of a blend of 95% high-density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and 5% mLLDPE, with a density in the range of 0.955 - 0.966 g / cm 3 .

[0133] Example 5 (EX5) - (PP / PP / PP)(PE / PE / PE)(PP / PP / PP) - All PP layers are made of homopolymer PP, with a density = 0.90 g / cm 3 , and a MFR in the range of 0.5 MFR to 2 MFR. All PE layers are made of a blend of 95% high-density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and 5% mLLDPE, with a density in the range of 0.955 - 0.966 g / cm 3 .

[0134] Example 6 (EX6) - (PP / PP / PP)(PE / PE / PE)(PP / PP / PP) - PP is made of homopolymer PP, with a density = 0.90 g / cm 3 , and a MFR in the range of 0.5 MFR to 2 MFR. PE is made of high-density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C.

[0135] Example 7 - (EX7) - (PP / PP / PP)(PE / PE / PE)(PP / PP / PP) - All PP layers are made of homopolymer PP with a density = 0.90 g / cm 3 and an MFR in the range of 0.5 MFR to 2 MFR. All PE layers are a blend of 95% high - density polyethylene with a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and a density in the range of 0.955 - 0.966 g / cm 3 and 5% mLLDPE.

[0136] Example 8 (EX8) - (PP1 / PP2 / PP1)(PE1 / PE2 / PE1)(PP1 / PP2 / PP1) PP1 is homopolymer PP with a density = 0.90 g / cm 3 and an MFR in the range of 0.5 MFR to 2 MFR. PP2 is made of homopolymer PP with an MFR of 0.25 and a density of 0.9. PE1 is high - density polyethylene with a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C. PE2 is ultra - high - molecular - weight polyethylene.

[0137] Example 9 (EX9) - (PP1 / PP2 / PP1)(PE / PE / PE)(PP1 / PP2 / PP1) - PP1 is made of homopolymer PP with a density = 0.90 g / cm 3 and an MFR in the range of 0.5 MFR to 2 MFR. PP2 is a blend of 95% homopolymer PP with a density = 0.90 g / cm 3 and an MFR in the range of 0.5 MFR to 2 MFR and 5% propylene - ethylene copolymer. PE is a blend of 92% high - density polyethylene with a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C and 8% olefin block copolymer.

[0138] Example 10 (EX10) - (PP / PP / PP)(PE / PE / PE)(PP / PP / PP) - All PP layers are made of homopolymer PP with a density = 0.90 g / cm 3has an MFR in the range of 0.5 MFR to 2 MFR. All of the PE layers are made of a blend of 95% high density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and a density in the range of 0.955 to 0.966 g / cm 3 and 5% mLLDPE. The layer composition of a comparative product was prepared as follows:

[0139] Comparative Example 1 (COM EX1) - (PP)(PE)(PP) - All of the PP layers are made of homopolymer PP, with a density = 0.90 g / cm 3 and has an MFR in the range of 0.5 MFR to 2 MFR. All of the PE layers are made of a blend of 95% high density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and a density range of 0.955 to 0.966 g / cm 3 and 5% mLLDPE.

[0140] Comparative Example 2 (COM EX2) - (PP)(PE)(PP) - All of the PP layers are made of homopolymer PP, with a density = 0.90 g / cm 3 and has an MFR in the range of 0.5 MFR to 2 MFR. All of the PE layers are made of a blend of 95% high density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and a density range of 0.955 to 0.966 g / cm 3 and 5% mLLDPE.

[0141] Comparative Example 3 (COM EX3) - (PP)(PE)(PP) - All of the PP layers are made of homopolymer PP, with a density = 0.90 g / cm 3 and has an MFR in the range of 0.5 MFR to 2 MFR. All of the PE layers are made of a blend of 95% high density polyethylene having a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and a density range of 0.955 to 0.966 g / cm 3 and 5% mLLDPE.

[0142] Comparative Example 4 (COM EX4) - (PP)(PE)(PP) - All PP layers are made of homopolymer PP with a density = 0.90 g / cm 3 , and have a melt flow rate (MFR) in the range of 0.5 MFR to 2 MFR. All PE layers have a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and 3 are made of a blend of 95% high density polyethylene with a density range of 0.955 - 0.966 g / cm and 5% mLLDPE.

[0143] Comparative Example 5 (COM EX5) - (PP)(PE)(PP) - All PP layers are made of homopolymer PP with a density = 0.90 g / cm 3 , and have a melt flow rate (MFR) in the range of 0.5 MFR to 2 MFR. All PE layers have a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and 3 are made of a blend of 95% high density polyethylene with a density range of 0.955 - 0.966 g / cm and 5% mLLDPE. Referring mainly to FIGS. 38 - 50 and further multilayer embodiments, where further Examples 11 - 38 are as follows:

[0144] Example 11 - Each PP and PE layer of the three - layer structure is itself made of a plurality of layers, preferably co - extruded and then laminated - (PP / PP / PP)(PE / PE / PE)(PP / PP / PP) - All PP layers are made of homopolymer PP with a density = 0.90 g / cm 3 , and have a melt flow rate (MFR) in the range of 0.5 MFR to 2 MFR. All PE layers have a melt index between 0.25 and 0.5 g / 10 min at 2.16 kg and 190 °C, and also a density range of 0.955 - 0.966 g / cm 3 are made of a blend of 95% high density polyethylene with a density range of 0.955 - 0.966 g / cm and 5% mLLDPE.

[0145] Example 12 - (PP1 / PP2 / PP3) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same as or different from PP1 and PP2, and is also a blend or block copolymer.

[0146] Example 13 - (PP1 / PP1) or (PP2 / PP2) or (PP1 / PP2) - PP1 is a polypropylene blend, and PP2 is a PP block copolymer.

[0147] Example 14 - (PP1 / PP1 / PP1) or (PP2 / PP2 / PP2) - PP1 is a polypropylene blend, and PP2 is a PP block copolymer.

[0148] Example 15 - (PP1 / PP2 / PP3) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same as or different from PP2, and is also a PP block copolymer.

[0149] Example 16 - (PP3 / PP2 / PP1) / (PP3 / PP2 / PP1) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same as or different from PP2, and is also a PP block copolymer.

[0150] Example 17 - (PP1 / PP2 / PP3) / (PP3 / PP2 / PP1) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same as or different from PP2, and is also a PP block copolymer.

[0151] Example 18 - (PP1 / PP2) / (PP3 / PP1) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same as or different from PP2, and is also a PP block copolymer.

[0152] Example 19 - (PP1 / PP2 / PP3 / PP1) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same as or different from PP2, and is also a PP block copolymer.

[0153] Example 20 - (PP1 / PP2 / PP3)-PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 contains an adhesion promoter.

[0154] Example 21 - (PO3 / PP2 / PP1)-PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PO3 is a polyolefin blend (e.g., PP + PE).

[0155] Example 22 - (PP1 / PP2 / PP3)-PP1 is a homopolymer PP + an additive that may contain any slip or block additive such as siloxane that changes the coefficient of friction as described herein. PP2 is the same or different homopolymer PP as that used in PP1 and includes copolymer PP which may be any propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer. PP3 is a homopolymer PP that is the same or different from that in PP1 and PP2 + an additive that changes the surface coefficient of friction (COF) and is the same or different from that used in PP1.

[0156] Example 23 - (PP3 / PP2 / PP1)-PP1 is a homopolymer PP + as described herein an additive that may contain any slip or block additive such as siloxane that changes the coefficient of friction (COF). PP2 is the same or different homopolymer PP as that used in PP1 and PP3 and includes copolymer PP which may be any propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer. PP3 is a homopolymer PP that is the same or different from that in PP1 and PP2 + an additive that changes the surface coefficient of friction and is the same or different from that used in PP1.

[0157] Example 24 - (PP3 / PP2 / PP1) or (PP1 / PP2 / PP3) - PP1 is a homopolymer PP + an additive that may contain any slip or block additive such as siloxane that changes the coefficient of friction (COF) as described herein. PP2 is the same or different homopolymer PP + any copolymer PP that may be a propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer as used in PP1 and PP3. PP3 is the same or different homopolymer PP + any copolymer PP that may be a propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer as in PP1 and PP2.

[0158] Example 25: A co - extruded PP precursor is proposed with the structure shown in Figure 41.

[0159] The additive for surface modification may contain any slip or antiblock additive such as siloxane. The copolymer may be any propylene - ethylene or ethylene - propylene random copolymer, block copolymer or elastomer.

[0160] The co - extruded PP precursor can be extruded at any blow - up ratio (BUR) between 0.9 and 1.5 to control the porosity. The co - extruded PP precursor is then either stretched sequentially in the MD - followed by the TD - or biaxially simultaneously. The biaxially stretched film can be further calendered to control the porosity.

[0161] Example 26: The second proposed structure can be as shown in Figure 44 for battery separator or textile applications.

[0162] With this structure, a higher degree of surface layer curvature for a water barrier in a high - speed water test can be designed.

[0163] The types of copolymers that can be incorporated into the above structure include, but are not limited to, propylene-ethylene or ethylene-propylene random copolymers, block copolymers or elastomers.

[0164] By extruding PP in a coextrusion form, the surface characteristics of the PP layer can be modified, and at the same time, it can be incorporated into a copolymer resin intermediate layer with a lower melting point to reduce the shutdown temperature. Different copolymer resins can also be incorporated into any part of the above structure to control the porosity of the TD stretched thin film.

[0165] By incorporating BUR into the precursor thin film, the porosity required in various applications can be further controlled.

[0166] Example 27 - (PP1 / PP2 / PP3)(PP1 / PP2 / PP3)(PP1 / PP2 / PP3)-PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same or a different PP block copolymer.

[0167] Example 28 - (PP3 / PP2 / PP1) / (PP3 / PP2 / PP1) / (PP3 / PP2 / PP1)-PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same or a different PP block copolymer.

[0168] Example 29 - (PP3 / PP2 / PP1)(PP1 / PP2 / PP3)(PP3 / PP2 / PP1) PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same or a different PP block copolymer.

[0169] Example 30 - (PP1 / PP2 / PP3)(PP3 / PP2 / PP1)(PP1 / PP2 / PP3) PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same or a different PP block copolymer.

[0170] Example 31 - (PP1 / PP2 / PP3)(PP3 / PP2 / PP1)(PP3 / PP2 / PP1) PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same or a different PP block copolymer.

[0171] Example 32 - (PP3 / PP2 / PP1)(PP1 / PP2 / PP3)(PP1 / PP2 / PP3) PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is the same or a different PP block copolymer.

[0172] Example 33 - (PP1 / PP2 / PP3)(PP1 / PP2 / PP3)(PP1 / PP2 / PP3) - PP1 is a homopolymer PP + an additive that may contain any slip or block additive such as siloxane that changes the coefficient of friction as described herein. PP2 is the same or a different homopolymer PP + a copolymer PP that may be any propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer used in PP1 and PP3. PP3 is the same or a different homopolymer PP as in PP1 and PP2 + contains an additive that changes the surface coefficient of friction, which may be the same or different from that used in PP1.

[0173] Example 34 - (PP3 / PP2 / PP1) / (PP3 / PP2 / PP1) / (PP3 / PP2 / PP1) - PP1 is a homopolymer PP + an additive that may contain any slip or block additive such as siloxane that changes the coefficient of friction as described herein. PP2 is the same or a different homopolymer PP + a copolymer PP that may be any propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer used in PP1 and PP3. PP3 is the same or a different homopolymer PP as in PP1 and PP2 + contains an additive that changes the surface coefficient of friction, which may be the same or different from that used in PP1.

[0174] Example 35 - (PP3 / PP2 / PP1)(PP1 / PP2 / PP3)(PP3 / PP2 / PP1) PP1 is a homopolymer PP + an additive that may contain any slip or block additive such as siloxane that changes the coefficient of friction as described herein. PP2 is the same as or different from that used in PP1 and PP3, a homopolymer PP + a copolymer PP that may be any propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer. PP3 is the same as or different from that in PP1 and PP2, a homopolymer PP + an additive that contains an additive that changes the surface coefficient of friction, which is the same as or different from that used in PP1.

[0175] Example 36 - (PP1 / PP2 / PP3)(PP3 / PP2 / PP1)(PP1 / PP2 / PP3) PP1 is a homopolymer PP + an additive that may contain any slip or block additive such as siloxane that changes the coefficient of friction as described herein. PP2 is the same as or different from that used in PP1 and PP3, a homopolymer PP + a copolymer PP that may be any propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer. PP3 is the same as or different from that in PP1 and PP2, a homopolymer PP + an additive that contains an additive that changes the surface coefficient of friction, which is the same as or different from that used in PP1.

[0176] Example 37 - (PP1 / PP2 / PP3)(PP3 / PP2 / PP1)(PP3 / PP2 / PP1) PP1 is a homopolymer PP + an additive that may contain any slip or block additive such as siloxane that changes the coefficient of friction as described herein. PP2 is a copolymer PP that may be the same as or different from that used in PP1 and PP3, and may be any propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer. PP3 is a homopolymer PP that may be the same as or different from that in PP1 and PP2, and contains an additive that changes the surface coefficient of friction, which may be the same as or different from that used in PP1.

[0177] Example 38 - (PP3 / PP2 / PP1)(PP1 / PP2 / PP3)(PP1 / PP2 / PP3) PP1 is a homopolymer PP + an additive that may contain any slip or block additive such as siloxane that changes the coefficient of friction as described herein. PP2 is a copolymer PP that may be the same as or different from that used in PP1 and PP3, and may be any propylene ethylene or ethylene - propylene random copolymer, block copolymer or elastomer. PP3 is a homopolymer PP that may be the same as or different from that in PP1 and PP2, and contains an additive that changes the surface coefficient of friction, which may be the same as or different from that used in PP1.

[0178] The composition of a certain comparative product may be as follows (for the comparative examples of the present invention being compared, preferably, it may have approximately the same thickness, the same thickness and porosity, or the same thickness, porosity and Gurley, and / or may be normalized for porosity and / or Gurley): Comparative 6 - Typical single - layer PP (e.g., Celgard 2500) Comparative 7 - Typical laminated three - layer (PP / PE / PP) Comparative 8 - Typical ceramic - coated version of typical single - layer PP or typical three - layer (PP / PE / PP)

[0179] Characteristic Determination of Examples - Characteristics Related to Separators and Battery Performance Thickness (μm) Using an Emveco Microgage 210-A micrometer thickness tester and test procedure ASTM D374, the thickness is measured in micrometers (μm). The thicknesses of Examples 1 to 6 and Comparative Examples 1 to 4 were determined and reported in the tables in Figures 22 and 23. Comparative examples having thicknesses corresponding to the examples were prepared so that the separators could be significantly compared.

[0180] Basis Weight (mg / cm 2 ) The basis weights of Examples 1 to 6 and Comparative Examples 1 to 4 were determined and reported in the table in Figure 22.

[0181] JIS Gurley (s / 100cc) Gurley is defined here as in the Japanese Industrial Standards (JIS Gurley) and measured here using an OHKEN permeability tester. JIS Gurley is defined as the time in seconds required for 100 cc of air to pass through a 1 square inch thin film at a constant pressure of 4.9 inches of water. The JIS Gurley of Examples 1 to 6 and Comparative Examples 1 to 4 was measured and reported in the table in Figure 22.

[0182] MD Shrinkage Rate at 105°C / 1 hour (%) The shrinkage rate is measured by placing the test sample between two sheets of paper, then fastening them together, holding the sample between the papers, and suspending it in an oven. For the "105°C for 1 hour" test, the sample is placed in the oven at 105°C for 1 hour. After the indicated heating time in the oven, each sample is removed, taped to a flat opposite surface using double-sided adhesive tape, the sample is flattened and smoothed, and the exact length and width are measured. The shrinkage rate is measured in both the machine direction (MD) and the transverse direction (TD) and expressed as the MD shrinkage rate (%) and the TD shrinkage rate (%).

[0183] The MD shrinkage rates of Examples 1 to 6 and Comparative Examples 1 to 4 were measured and reported in the table in FIG. 22.

[0184] MD Tensile Strength (kgf / cm 2 ) The machine direction (MD) tensile strength is measured using an Instron Model 4201 according to the ASTM-882 procedure. The MD tensile strengths of Examples 1 to 6 and Comparative Examples 1 to 4 were measured and reported in the table in FIG. 22.

[0185] MD Elongation (%) The MD breaking elongation (%) is the percentage of elongation of the test sample along the machine direction of the test sample measured at the maximum tensile strength required to break the sample. The MD elongations of Examples 1 to 6 and Comparative Examples 1 to 4 were measured and reported in the table in FIG. 22.

[0186] TD Tensile Strength (kgf / cm 2 ) The transverse direction (TD) tensile strength is measured using an Instron Model 4201 according to the ASTM-882 procedure. The TD tensile strengths of Examples 1 to 6 and Comparative Examples 1 to 4 were measured and reported in the table in FIG. 22.

[0187] TD Elongation (%) Reported in the table in FIG. 22. The TD breaking elongation (%) is the percentage of elongation of the test sample along the transverse direction of the test sample measured at the maximum tensile strength required to break the sample. The TD elongations of Examples 1 to 6 and Comparative Examples 1 to 4 were measured and reported in the table in FIG. 22.

[0188] Puncture Strength (gf) The puncture strength is measured using an Instron Model 4442 based on ASTM D3763. The measurement is performed across the width of the microporous membrane, and the puncture strength is defined as the force required to puncture the test sample. The puncture strengths of Examples 1 to 6 and Comparative Examples 1 to 4 were measured and reported in the table in FIG. 22.

[0189] As one idea, UHMW polymers are used to increase puncture strength. However, these polymers, which can have a molecular weight greater than 1,000,000, cause processing difficulties, especially when the process is a dry process such as the CELGARD® dry process. By leveraging these techniques, it is possible to reduce the need to use polymers with a molecular weight exceeding 1M, which can be very difficult to process, especially in dry process membranes.

[0190] DB average (V) A voltage is applied to the separator membrane until dielectric breakdown of the sample is observed. Strong separators exhibit high DB. Any non-uniformities in the separator membrane cause lower DB values. Battery separators with higher average DB, particularly higher minimum DB values, make the battery safer when used in a battery. The average DB of Examples 1 - 6 and Comparative Examples 1 - 4 was measured and reported in the table in FIG. 22.

[0191] DB minimum value (V) A voltage is applied to the separator membrane until dielectric breakdown of the sample is observed. Strong separators exhibit high DB. Any non-uniformities in the separator membrane cause lower DB values. Battery separators with higher average DB, particularly higher minimum DB values, make the battery safer when used in a battery. The minimum DB for Examples 1 - 6 and Comparative Examples 1 - 4 was measured and reported in the table in FIG. 22.

[0192] DB uniformity The DB values of Examples 1, 4, and 5 were compared with Comparative Examples 1, 2, and 4. The results are shown in FIG. 18. The DB standard deviation was calculated and reported.

[0193] Mixed intrusion average (N) Mixing intrusion is the force required to cause a short circuit through the separator when placed between the cathode material and the anode material. This test is used to show the tendency of the separator to cause a short circuit during battery assembly. Details of this method are described in US2010 / 209758, which is incorporated herein by reference in its entirety. The mixing intrusion values in Examples 1-6 and Comparative Examples 1-4 were calculated and reported in the table in Figure 22.

[0194] Nail penetration test When Examples 1-9 and Comparative Examples 1-5 were tested, Examples 1 and 6 passed the nail penetration test. None of the comparative examples passed the nail penetration test. The nail penetration tests at speeds of 1 cm / second and 10 cm / second are described in U.S. Patent No. 9,065,152, which is incorporated herein by reference in its entirety.

[0195] Shutdown temperature (°C) Record the start temperature of shutdown at a resistance reading of 100 W×cm 2 and report in °C. The shutdown temperatures for Examples 1-6 and Comparative Examples 1-4 were measured and reported in the table in Figure 22.

[0196] Shutdown speed (Ω-cm 2 ) The thin film of the example is sandwiched between two nickel disks and wetted with a PC solvent. The wetted separator stack is then subjected to a temperature gradient of 60 °C / min. During the duration of the test, the resistance between the two nickel disks is monitored by a multimeter. According to the definition of shutdown in this test, the resistance should increase by two orders of magnitude from 100 W×cm 2 to 10,000 W×cm 2 and is normalized by the time required for this increase in resistance. The results for the shutdown speed are reported in units of W×cm 2 / second. The shutdown speeds of Examples 1-6 and Comparative Examples 1-4 were measured and reported in the table in Figure 22.

[0197] ER (Ω-cm2 ) The ER method uses an electrolyte solution composed of a solvent mixture of DI water and 2-propanol. The electrical resistance is evaluated by continuously adding four circular separator disks (38 mm in diameter) between two metal electrodes. The resistance value of the separator is measured in Ω using an LCR meter and then multiplied by the area of the electrode to obtain Ω-cm 2 to obtain. The electrolyte resistivity is measured using a YSI meter.

[0198] Calculation: 1) Average separator resistance of continuous separator layer, (Ω) = (R 層4 Ω - R 層3 Ω + R 層3 Ω - R 層2 Ω / 2 2) Electrical resistance, Ω-cm 2 = Average resistance Ω of continuous separator layer * Area of nickel-plated electrode cm 2

[0199] The QC-ER for Examples 1 to 6 and Comparative Examples 1 to 4 was determined and reported in the table in Figure 23.

[0200] MacMullin number The MacMullin number is calculated using the measured value of electrical resistance (ER). The calculation is as follows: MacMullin number = (electrical resistance, Ω-cm 2 / separator thickness, cm) / electrolyte resistivity (Ω-cm).

[0201] The MacMullin numbers for Examples 1 to 6 and Comparative Examples 1 to 4 were determined and reported in the table in Figure 23.

[0202] Cycle life All cycling was performed in constant current (CC) mode. The cathode used was 523NMC. The anode used was superior graphite. For the electrolyte, 1 M LiPF6 salt in a 3:7 v:v EC:EMC solvent was used. The voltage window was 3.0 - 4.3 V. For cycles 1 - 5, the charge rate and discharge rate were C / 10. For cycles 6 - 10, the charge rate and discharge rate were C / 5. For cycles 11 - 15, the charge rate was C / 5 and the discharge rate was C / 2. For cycles 16 - 20, the charge rate was C / 5 and the discharge rate was 1C (charge / discharge rate capacity; 1C is the full charge or discharge rate in 60 minutes). For cycles 21 - 25, the charge rate was C / 5 and the discharge rate was 5C. For cycles 26 - 30, the charge rate was C / 5 and the discharge rate was 10C. For cycles 31 - 35, the charge rate and discharge rate were C / 10.

[0203] The cycle lives of Example 1 and Comparative Example 1 were compared. This was done at a C rate of C / 3 with a 4.3 V cutoff at 523NCM relative to graphite. The data shown presents the average of 5 cells for each sample (or the total of 10 cells). The results are shown in Figure 19. Without wishing to be bound by any particular theory, this is thought to be due to improved electrolyte uptake, perhaps due to an increased interface, e.g., a laminated interface, and the complexity of the pore structure. A repeatable improvement in cycle life with the multilayer product compared to the conventional three layers is shown by this test.

[0204] Compressive elasticity The compressive elastic modulus was evaluated using a TMA Q400 and a hemispherical probe. 5 mm x 5 mm samples were compressed at a constant rate up to a maximum of 1 N (568 N / cm2), and then the pressure was released at a constant rate back to 0 N at ambient temperature. The percentage change in dimension during compression and recovery was estimated based on the initial thickness of the sample. The compressive elasticity of Example 1 and Comparative Example 1 was tested. The results are reported in Figure 5 and Table 1 below.

[0205]

Table 1

[0206] The micro-layer structure imparts higher compression recovery than equivalent wet-process membranes. In certain applications, it may be desirable to have less squeezing and / or better compression recovery.

[0207] Pin removal Pin removal data at attachment was collected using a pin removal winder. The machine was equipped with a 45 mm slit roll, and a separator roll was mounted on the machine onto a split pin mandrel (4 mm diameter). The separator was wound onto the mandrel and the pin was pulled off. The maximum removal force was recorded and reported in Newtons. For each test sample, the outer diameter was kept constant, and the tension and length of the thin film varied based on the thin film thickness. It is best to compare thin films of the same or approximately the same thickness.

[0208] Characterization of Examples - Structural Characteristics AQ Porosity (%) The porosity of the microporous thin film samples was measured using ASTM method D - 2873 and defined as the void percentage in the microporous membrane measured in both the machine direction (MD) and the transverse direction (TD). The AQ porosity for Examples 1 - 6 and Comparative Examples 1 - 4 was calculated. It is reported in the table in Figure 22. Some additional porosity data for Example 1 was determined. It is reported in Table 2 below:

[0209]

Table 2

[0210] Aquapore Porosity (%) The Aquapore (AQ) porosity for Examples 1 - 6 and Comparative Examples 1 - 4 was measured. It is reported in the table in Figure 23.

[0211] AQ PP Pore Size (μm) The pore diameter is measured using Aquapore, which is available through Porous Materials Inc. (PMI). The pore diameter is expressed in μm. The AQ PP pore diameters for Examples 1 to 6 and Comparative Examples 1 to 4 were calculated and reported in the table in Figure 22. Additional data for Examples 1, 9, and 10 were obtained and reported in Table 2.

[0212] AQ PE pore diameter (μm) The pore diameter is measured using Aquapore, which is available through Porous Materials Inc. (PMI). The pore diameter is expressed in μm. The AQ PE pore diameters for Examples 1 to 6 and Comparative Examples 1 to 4 were determined and reported in the table in Figure 22. Additional data for Examples 1, 9, and 10 were obtained and reported in Table 2.

[0213] AQ surface area (m 2 / g) Aquapore is a water intrusion measurement technique and is only available for testing base films. In this measurement, a wide area of the film is immersed in water and pressurized to 3,000 psi. The test results are the overall porosity of the film (reported in %), the pore diameters of PP and / or PE (reported in μm), and the surface areas inside and outside the pores (reported in m 2 / g). The sample mass must be ≥ 3 g for each aquapore measurement. The AQ surface areas for Examples 1 to 6 and Comparative Examples 1 to 4 were determined and reported in the table in Figure 22. Additional data for Examples 1, 9, and 10 were obtained and reported in Table 2.

[0214] Pore diameter distribution The pore diameter distributions of Example 6 and 11 and Comparative Example 4 were measured using mercury intrusion porosimetry. The results are shown in Figure 33. The pore diameters in Comparative Example 4 were larger than those in the examples of the present invention and had a narrower distribution.

[0215] Calculated tortuosity. The tortuosity was calculated by the following formula (1): N m = T 2 / P(1), wherein N m is a Maclaurin number, T is the degree of tortuosity, and P is the porosity. Although not wishing to be bound by any particular theory, it is said that a battery separator having a higher degree of tortuosity is safer. This is because dendritic crystals growing from the anode to the cathode have to follow a more convoluted path, making it more difficult for dendritic crystals to grow between the electrodes. The calculated degrees of tortuosity for Examples 1 to 6 and Comparative Examples 1 to 4 are given in the table in FIG. 23.

[0216] SEM image 1. Processing conditions Procedure for cross-sectional observation by scanning electron microscope (SEM). a.) Cut the sample into an appropriate size (several mm square). b.) Produce a flat cross-section by ion milling (MD-ND plane). Ion milling equipment: E-3500 (Hitachi High-Technologies Corporation.) Ion source: Ar+ Acceleration voltage: 3.5 kV Discharge voltage: 2.0 kV Stage control: 5 (set value) Processing time: 4 hours Temperature: 20 - 25 °C c.) Attach the sample to the stub using double-sided carbon conductive tape and carbon paste. d.) Apply osmium plasma coating to impart conductivity to the sample. 2. SEM observation conditions a.) Equipment: S-4800 (Hitachi High-Technologies Corporation.) Acceleration voltage: 1 kV Working distance: approximately 5 mm

[0217] SEM images of Examples 1, 2, 4, and 6 and Comparative Examples 1, 4, and 5 were taken. Some of these images are shown in FIGS. 24 to 30. It was found that there were different structural differences between the multilayer products in the examples and the three-layer products in the comparative examples. For example, while the PP layer of the three-layer product contained more columnar or vertically continuous amorphous regions, the amorphous regions of the multilayer PP regions (having three layers of PP in the examples) were mostly discontinuous and non-columnar. The control comparisons in FIGS. 28 to 30 show these differences between the multilayer and three-layer products.

[0218] Machine learning test Detailed procedure 1: Image feature extraction for obtaining a machine learning vector · Read the image by the OpenCV python module cv2 · Obtain 50 partial images of 240×160 pixels^2 at random positions uniformly from either the PP or PE region, and normalize the image by using cv2.normalize with α = 0, β = 255, and norm_type = cv2.NORM_MINMAX. Normalize. · For each partial image, use the SIFT feature detector cv2.x features 2d.SIFT_create with default settings to obtain features with angles and sizes. Convert each angle a of the obtained features to a' = 90 - |a mod 180 - 90|. · For i from 1 to 9, count the number of angles a' converted in the range of [10 * (i - 1), 10 * i], which is called bin count. · Concatenate the 9 bin counts, the average feature size (scalar), and the number of features (scalar) to obtain the feature vector x k (11 - dimensional) (k - th image). · Collect the median of 11 features from 50 partial images to obtain the feature vector x of the input image.

[0219] The rules for the OpenCV Python module cv2 include Python Machine Learning by Raschka (ISBN1783555130) and OpenCV by Michael Beyeler (1785282697). All of these rules are hereby incorporated by reference into this specification in their entirety. Further information on OpenCV can be found at https: / / en.wikipedia.org / wiki / OpenCV.

[0220] Example of the PP layer: · After obtaining the feature vector x from the PP layer by the procedure 1 described below, each value x in x is standardized as x'=(x - m) / s using the following mean vector m = [0.121252742025, 0.0932702969461, 0.0637613832138, 0.0471628522627, 0.0410994787666, 0.0455612990903, 0.0663893557564, 0.143913936237, 0.373695714612, 3.470413863, 569.830508475] and standard deviation vector s = [0.0177890460233, 0.0126226741459, 0.0109280746046, 0.00952236047605, 0.00919810029221, 0.00802167410741, 0.00965575771023, 0.0135729399588, 0.0556357096109, 0.181326979354, 52.6681415756]. · Let w be [-2.29884147179, -0.120953660963, 0.609748975014, -0.354807579078, 0.0742943451505, -0.0596756155513, 0.679531409197, 1.18484320645, 0.639551068782, -0.123277373445, 0.495565514875], and calculate the inner product of w T with x'. · w T When w x'> -1.27465281948, classify the image into 9 layers.

[0221] Examples of the PE layer: · After obtaining the feature vector x from the PE layer by the procedure 1 described below, each value x in x is normalized as x' = (x - m) / s using the following average vector m = [0.0753659021681, 0.0647442404474, 0.052445934828, 0.0441842705626, 0.0424971059836, 0.0495261454071, 0.0745156791392, 0.15315494777, 0.434028151238, 3.51412063686, 480.02173913] and standard deviation vector s = [0.0212709138539, 0.0156303526361, 0.0100887199823, 0.00610554172426, 0.00588628646619, 0.00509466227247, 0.00868424601387, 0.0177249443105, 0.0499726205047, 0.217925555283, 60.5317430669]. Let w be [0.0026717153, -0.2072501509, -0.4883326802, 0.0172248418, -0.5467527574, -0.389222 5728, 0.7356477088, 1.1574408691, -1.1992044378, -1.920101147, 0.1068808983, 0.6542173447], and calculate the inner product of w T with x' · w T When w · x' > -0.6542173447, classify the image into 9 layers.

[0222] By subjecting Examples 1, 2, 4, 7, 8, and 10, as well as Comparative Examples 1, 4, and 5, to a machine learning test, it was determined whether the comparative (three-layer) examples and the examples of the present invention (multi-layer) could be distinguished by this test. The results are shown in Figures 34 to 37. The comparative (three-layer) examples and the examples of the present invention (multi-layer) could be distinguished.

[0223] DSC Perform DSC analysis to determine the melting point (T m ) and the onset of crystallization. Use a Netzsch DSC200F3 model together with a sealed aluminum sample holder with a perforated lid. Use nitrogen as the carrier gas at 40 ml / min to prevent oxidation of the sample. The mass of the analyzed sample varies from 5 to 6 mg. T m To determine the onset of melting and crystallization, the sample is first subjected to a heat treatment to erase the thermal history. Then, another heating and cooling cycle at 10 °C / min from 25 °C to 300 °C is performed by the instrument. The acquisition and handling of data are performed by Proteus Analysis software. Examples 1, 3, 5, and 6 as well as Comparative Examples 1, 2, 3, and 4 were evaluated by DSC. The PE layer and the PP layer were evaluated separately. The results are shown in Figures 31 and 32.

[0224] According to at least selected embodiments, the present application, disclosure, and invention relate to novel or improved membranes, separator membranes, separators, battery separators, lithium secondary battery separators, multilayer membranes, multilayer separator membranes, multilayer separators, multilayer battery separators, multilayer lithium secondary battery separators, and / or multilayer battery separators, novel or improved batteries, capacitors, fuel cells, lithium batteries, lithium ion batteries, lithium secondary batteries, and / or lithium ion secondary batteries, and / or methods of making and / or using such membranes, separator membranes, separators, battery separators, lithium secondary battery separators, batteries, capacitors, fuel cells, lithium batteries, lithium ion batteries, lithium secondary batteries, and / or lithium ion secondary batteries, and / or devices, vehicles, or products containing the same. According to at least certain embodiments, the present disclosure or invention relates to novel or improved membrane layers, membranes or separator membranes, battery separators containing such membranes, and / or related methods. According to at least certain selected embodiments, the present disclosure or invention relates to novel or improved porous polymer membranes or separator membranes, battery separators containing such membranes, and / or related methods. According to at least certain embodiments, the present disclosure or invention relates to novel or improved microporous polyolefin membranes or separator membranes, micro-layer membranes, multilayer membranes including one or more micro-layers or nano-layer membranes, battery separators containing such membranes, and / or related methods. According to at least certain embodiments, the present disclosure or invention relates to novel, optimized, or improved microporous stretched polymer membranes or separator membranes having one or more novel or improved outer layers and / or inner layers, micro-layer membranes, multilayer microporous membranes or separator membranes having outer and inner layers, some of such layers or sub-layers being created by co-extrusion and then laminated together to form the above novel, optimized, or improved membrane or separator membrane.In some embodiments, a layer, micro-layer or nano-layer may comprise a homopolymer, copolymer, block copolymer, elastomer, and / or polymer blend. In selected embodiments, at least a layer, micro-layer or nano-layer may comprise different or distinct polymers, homopolymers, copolymers, block copolymers, elastomers, and / or polymer blends. This. The disclosure or invention also relates to novel or improved methods of making such membranes, separator membranes, or separators, and / or novel or improved methods of using such membranes, separator membranes or separators, for example, as lithium battery separators. According to at least selected embodiments, the present application or invention is directed to novel or improved multi-layer and / or micro-layer porous or microporous membranes, separator membranes, separators, composites, electrochemical devices, and / or batteries, and / or methods of making and / or using such membranes, separators, composites, devices and / or batteries. According to at least certain selected embodiments, the present application or invention is directed to a novel or improved separator membrane that is multi-layered, wherein one or more layers of the multi-layer structure are manufactured in a multi-layer or micro-layer co-extrusion die having a plurality of extruders. The novel or improved membranes, separator membranes, or separators described above may preferably demonstrate improved shutdown, improved strength, improved dielectric breakdown strength, and / or reduced tendency to tear.

[0225] According to at least selected embodiments, this application or invention is directed to additives for improved battery performance, improved additive-containing membranes, improved battery separators, and / or improved batteries, and / or related methods for their manufacture and / or use. According to at least some embodiments, this application or invention is directed to additive-containing membranes, separator membranes, and / or battery separators, and / or methods for making and / or using such membranes, separator membranes, and / or battery separators. According to at least certain embodiments, this application or invention is directed to the incorporation of additives into microporous or separator membranes for use in lithium secondary batteries, such as lithium ion secondary batteries, improved battery separators, and / or related methods. In some embodiments, the membranes may contain additives that improve performance in battery chemistries, such as in lithium ion batteries. In other selected embodiments, the membranes may contain additives that improve pin removal performance, such as siloxane or lithium stearate. In some other embodiments, the invention may also relate to methods for making such membranes or separator membranes, and methods for using such membranes or separator membranes as, for example, lithium battery separators. According to at least selected embodiments, this application or invention is directed to novel or improved porous membranes, separator membranes, separators, dry process separators, composites, electrochemical devices, batteries, and methods for making such membranes, separators, composites, devices, and / or batteries. According to at least some selected embodiments, the invention is directed to novel or improved separator membranes containing additives or elastomers. The improved membranes may preferably demonstrate improved shutdown, improved strength, improved dielectric breakdown strength, and / or reduced tendency to tear.According to at least certain selected embodiments, this application or invention is a battery separator having a microporous polymer thin film or membrane and an optional coating layer on at least one surface of the microporous polymer thin film, wherein at least one of the microporous polymer thin film and the optional coating contains an additive. The additive may be selected from the group consisting of lubricants, plasticizers, nucleating agents, shrinkage reducing agents, surfactants, SEI modifiers, cathode protectants, flame retardant additives, LiPF6 salt stabilizers, overcharge preventers, aluminum corrosion preventers, lithium deposition or deposition regulators, or solvation promoters, aluminum corrosion preventers, wetting agents, viscosity modifiers, friction reducers, COF reducers, pin removal force reducers, copolymers, block copolymers, and / or combinations thereof. Also described herein is a battery, including a primary or secondary lithium ion battery, comprising one or more of the above thin films, membranes, coatings, and / or separators. Also described is a method of making the above thin films, membranes, coatings, and / or battery separators. According to at least certain embodiments, this application or invention is an improved or novel battery separator having at least one of increased puncture strength, decreased pin removal force, improved electrolyte wetting, and increased pore size. - A battery separator having a microporous polymer thin film with an optional coating layer on at least one of its surfaces, an optional coating, and at least one of the microporous polymer thin films therein and / or thereon, an additive selected from the group consisting of a lubricant, a surfactant, a nucleating agent, a shrinkage reducing agent, and / or a plasticizer, a microporous polymer thin film having an additive mainly present in at least one surface region of the thin film, or present in a single surface region of the thin film, or present in the first surface region of the thin film and the second surface region of the thin film opposite to the first surface region, or present throughout the thin film, a coating applied to the surface of the microporous polymer thin film, the coating may be applied only to one surface of the microporous polymer thin film, or may be applied to the first surface of the microporous polymer thin film, and another coating may be applied to the second surface of the microporous polymer thin film opposite to the first surface, the above coating, and / or combinations thereof. According to at least a preferred embodiment, the microporous polymer thin film or membrane is a microporous polyolefin film such as a dry stretching process film such as a single-layer dry process thin film, a two-layer dry process thin film, or a multi-layer dry process thin film. Also, according to at least a preferred embodiment, one, two, three, four, or all five of different types of additives may be added, or a single additive acting as one, two, three, four, or all five of different types of additives may be added to the thin film, coating, or separator. For example, an additive that is both a lubricant and a surfactant may be added therein or thereon.

[0226] The microporous multilayer battery separators described herein, in some embodiments, exhibit improved safety, strength, and durability as compared to previous two-layer, three-layer, or multilayer battery separators. For example, the separator may exhibit increased average dielectric breakdown (DB), increased minimum DB, increased shutdown rate, and increased degree of bend, all of which indicate a safer battery separator. The separator may also exhibit increased puncture strength and increased mixed intrusion value, indicating a stronger and more durable battery.

[0227] These properties of the microporous multilayer battery separators described herein are, at least in part, the result of the way the separator is made. This method, in some embodiments, includes at least coextruding two or more polymer mixtures to form a first coextruded two-layer, three-layer, or multilayer thin film, coextruding two or more other polymer mixtures to form a second coextruded two-layer, three-layer, or multilayer thin film, and coextruding two or more additional polymer mixtures to form a third coextruded two-layer, three-layer, or multilayer thin film. Coextrusion typically involves using a coextrusion die with one or more extruders (typically one extruder per layer of the two-layer, three-layer, or multilayer thin film) that supply the die. The polymer mixtures used to form each layer of the first, second, and third two-layer, three-layer, or multilayer thin films may be the same or different. The mixtures may include one polymer, or more than one polymer, such as a polymer blend. Also, more than three two-layer, three-layer, or multilayer thin films may be formed. After the first, second, and third two-layer, three-layer, or multilayer thin films are formed, these thin films are laminated together with two of the thin films formed on opposite faces of one of these thin films to form the microporous battery separator described herein.

[0228] The microporous multilayer battery separator described in this specification can be used in lithium-ion batteries including lithium secondary batteries, resulting in batteries with improved safety and durability.

[0229] The battery separator in this specification can be described in several different ways.

[0230] In a first aspect, a battery separator for a lithium battery is described in this specification. In some embodiments, the battery separator includes at least one microporous separator membrane or sub-membrane including a plurality of porous or microporous polymer micro-layers or nano-layers, with at least one of the individual micro-layers or nano-layers including a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend, or including a different or distinct additive, agent, material, and / or filler, or including a combination of different or distinct polymers, molecular weight polymers, homopolymers, copolymers, polymer blends, additives, agents, materials, and / or fillers compared to adjacent individual micro-layers or nano-layers. In some embodiments, a plurality of the above separator membranes or sub-membranes of the polymer micro-layers or nano-layers are laminated to each other or to a microporous polymer membrane. In some embodiments, at least one of the above separator membranes or sub-membranes of the polymer micro-layers or nano-layers has at least three micro-layers or nano-layers. Optionally, at least one of the above separator membranes or sub-membranes of the polymer micro-layers or nano-layers is made of one or more polyolefins. Optionally, at least one of the above separator membranes or sub-membranes of the polymer micro-layers or nano-layers is made of co-extruded dry process polyolefin micro-layers or nano-layers. In some embodiments, at least two of the above separator membranes or sub-membranes of the polymer micro-layers or nano-layers. In some embodiments, at least three of the above separator membranes or sub-membranes of the polymer micro-layers or nano-layers.

[0231] Described herein are multilayer microporous thin films or membranes that can exhibit improved properties, including improved dielectric breakdown and strength, compared to prior single-layer or trilayer microporous membranes of the same thickness. Preferred multilayer microporous membranes include micro-layers and one or more laminated barriers. Also disclosed are battery separators or batteries that include one or more of the multilayer microporous thin films or membranes. The batteries and battery separators of the present invention are preferably safer and more robust than batteries and battery separators using prior single-layer and trilayer microporous membranes. Also described herein is a method of making the multilayer microporous separators, membranes or thin films described herein.

[0232] Depending on at least certain embodiments, aspects, or objectives, the following may be disclosed, provided, or expected:

[0233] A battery separator for a lithium battery, comprising at least one microporous separator membrane or sub-membrane comprising a plurality of porous or microporous polymer micro-layers or nano-layers, wherein at least one of the individual micro-layers or nano-layers comprises a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend than an adjacent individual micro-layer or nano-layer, or comprises different or distinct additives, agents, materials, and / or fillers, or comprises different or distinct polymers, molecular weight polymers, homopolymers, copolymers, polymer blends, additives, agents, materials, and / or fillers.

[0234] The battery separator as described above, wherein a plurality of the separator membranes or sub-membranes of polymer micro-layers or nano-layers are laminated to each other or to a microporous polymer membrane.

[0235] The battery separator as described above, wherein at least one of the separator membranes or sub-membranes of polymer micro-layers or nano-layers has at least three micro-layers or nano-layers.

[0236] At least one of the separator membranes or sub-membranes of the polymer micro layer or nano layer is The above battery separator made of one or more polyolefins.

[0237] At least one of the separator membranes or sub-membranes of the polymer micro layer or nano layer is made of a co-extruded dry process polyolefin micro layer or nano layer, the above battery separator.

[0238] The above battery separator including at least two of the separator membranes or sub-membranes of the polymer micro layer or nano layer.

[0239] The above battery separator including at least three of the separator membranes or sub-membranes of the polymer micro layer or nano layer.

[0240] The battery separator or separator membrane shown or described in this specification.

[0241] A lithium battery including the above battery separator.

[0242] An improved separator, membrane or base thin film, wherein the separator is a multi-layer separator, membrane, or base thin film including one or more microporous co-extruded micro multi-layer or nano multi-layer polymer membranes or sub-membranes adapted to be laminated or adhered to another polymer membrane, and at least one of the individual micro layers or nano layers includes a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend, or includes a different or distinct additive, agent, material, and / or filler, or includes a combination of different or distinct polymers, molecular weight polymers, homopolymers, copolymers, polymer blends, additives, agents, materials, and / or fillers, the above improved separator, membrane or base thin film.

[0243] A battery separator or separator membrane comprising one or more coextruded micro multilayer films laminated or adhered to another polymer film, wherein the separator or separator membrane can impart improved strength, for example, improved puncture strength, at a particular thickness, and can also exhibit improved shutdown and / or reduced tendency to tear, and at least one of the individual micro layers contains a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend compared to an adjacent individual micro layer, or contains a different or distinct additive, drug, material, and / or filler, or contains a combination of different or distinct polymers, molecular weight polymers, homopolymers, copolymers, polymer blends, additives, drugs, materials, and / or fillers.

[0244] A battery separator or separator membrane comprising one or more coextruded micro multilayer or nano multilayer films optionally laminated or adhered to another polymer film, which can exhibit improved strength, improved puncture strength, at a particular thickness, and / or can exhibit improved shutdown and / or reduced tendency to tear, and at least one of the individual micro layers or nano layers contains a different or distinct polymer, molecular weight polymer, homopolymer, copolymer, and / or polymer blend compared to an adjacent individual micro layer or nano layer, or contains a different or distinct additive, drug, material, and / or filler, or contains a combination of different or distinct polymers, molecular weight polymers, homopolymers, copolymers, polymer blends, additives, drugs, materials, and / or fillers.

[0245] A lithium battery comprising the above battery separator.

[0246] A lithium secondary battery comprising the above battery separator.

[0247] A lithium ion battery comprising the above battery separator.

[0248] An improved battery separator comprising a multilayer microporous thin film having 9 or more layers, wherein at least three consecutive layers of the microporous thin film have a thickness of 0.1 to 5 microns, the above-mentioned battery separator.

[0249] The above-mentioned battery separator, wherein at least three consecutive layers of the microporous thin film have a thickness of 0.1 to 3 microns.

[0250] The above-mentioned battery separator, wherein at least three consecutive layers of the microporous thin film have a thickness of 0.1 to 2.5 microns.

[0251] The above-mentioned battery separator, wherein at least three consecutive layers of the microporous thin film have a thickness of 0.1 to 2.0 microns.

[0252] The above-mentioned battery separator, wherein the multilayer microporous thin film has a thickness of 1 micron to 30 microns.

[0253] The above-mentioned battery separator, wherein the multilayer microporous thin film has a thickness of 1 micron to 20 microns.

[0254] The above-mentioned battery separator, wherein the multilayer microporous thin film has a thickness of 1 micron to 15 microns.

[0255] The above-mentioned battery separator, wherein the multilayer microporous thin film has a thickness of 1 micron to 10 microns.

[0256] The above-mentioned battery separator, wherein at least three consecutive layers are coextruded layers.

[0257] The above-mentioned battery separator, wherein at least three consecutive coextruded layers are laminated together with at least one other layer to form a microporous polymer thin film.

[0258] The above-mentioned battery separator, wherein at least one other layer is a coextruded layer.

[0259] The above-described battery separator, wherein at least three continuous layers comprise a polyolefin or a polyolefin blend.

[0260] The above-described battery separator, wherein at least three continuous layers each comprise polyethylene.

[0261] The above-described battery separator, wherein at least three continuous layers each comprise polypropylene.

[0262] The above-described battery separator, wherein the multilayer microporous film comprises 12 or more layers.

[0263] The above-described battery separator, wherein the multilayer microporous film comprises 15 or more layers.

[0264] The above-described battery separator, wherein the multilayer microporous film comprises 18 or more layers.

[0265] The above-described battery separator, wherein the multilayer microporous film comprises 21 or more layers.

[0266] The above-described battery separator, wherein the multilayer microporous film comprises 24 or more layers.

[0267] The above-described battery separator, wherein the multilayer microporous film comprises 27 or more layers.

[0268] The above-described battery separator, wherein the multilayer microporous film comprises 30 or more layers. The above-described battery separator, wherein the multilayer microporous film has a puncture strength of 290 gf or more.

[0269] The above-described battery separator, wherein the multilayer microporous film has a puncture strength of 300 gf or more.

[0270] The above-described battery separator, wherein the multilayer microporous film has a puncture strength of 310 gf or more.

[0271] A battery comprising one or more of the above-described battery separators.

[0272] A method of forming an improved battery separator comprising a multilayer microporous membrane, comprising: coextruding at least two layers; laminating at least two coextruded layers to at least one other layer to form a multilayer microporous membrane The above method.

[0273] The above method, wherein at least three layers are coextruded.

[0274] The above method, wherein at least four layers are coextruded.

[0275] The above method, wherein at least five layers are coextruded.

[0276] The above method, wherein at least six layers are coextruded.

[0277] The above method, wherein at least seven layers are coextruded.

[0278] The above method, wherein at least eight layers are coextruded.

[0279] The above method, wherein at least nine layers are coextruded.

[0280] The above method, wherein at least ten layers are coextruded.

[0281] The above method, wherein at least one other layer is a coextruded layer.

[0282] The above method, wherein at least one other layer is a single-extruded layer.

[0283] The above method, wherein at least two coextruded layers are laminated to two other layers.

[0284] One of the other two layers is laminated on the first surface of the at least two coextruded layers, and the second of the other two layers is laminated on the surface of the at least two coextruded layers that is opposite to the first surface. The above method, wherein the layer is laminated.

[0285] The above method, wherein at least one of the other two layers is a coextruded layer.

[0286] The above method, wherein both of the other two layers are coextruded layers.

[0287] The above method, wherein at least one of the other two layers is a coextruded layer.

[0288] The above method, wherein both of the other two layers are coextruded layers.

[0289] The above method, wherein at least one of the at least two coextruded layers and the other layer comprise a polyolefin or a polyolefin blend.

[0290] The above method, wherein at least one of the at least two coextruded layers comprises a polyolefin or a polyolefin blend different from that contained in the other layer.

[0291] The above method, wherein at least one of the at least two coextruded layers comprises polypropylene and the other layer comprises polyethylene.

[0292] The above method, wherein at least one of the at least two coextruded layers comprises polyethylene and the other layer comprises polypropylene.

[0293] The above method, wherein each of the other two layers comprises polypropylene or each of the other two layers comprises polyethylene.

[0294] The above method, wherein each of the other two layers comprises polypropylene or each of the other two layers comprises polyethylene.

[0295] The above method, wherein each of the other two layers contains polypropylene or each contains polyethylene.

[0296] The above method, wherein each of the other two layers contains polypropylene or each contains polyethylene.

[0297] The above method, wherein each of the other two layers contains polypropylene or each contains polyethylene.

[0298] The above method, wherein each of the other two layers contains polypropylene or each contains polyethylene.

[0299] The above method, wherein at least one of the other two layers is a coextruded layer coextruded with two or more other layers.

[0300] The above method, wherein at least one of the other two layers is a coextruded layer coextruded with three or more other layers.

[0301] The above method, wherein at least one of the other two layers is a coextruded layer coextruded with four or more other layers.

[0302] The above method, wherein at least one of the other two layers is a coextruded layer coextruded with five or more other layers. The above method.

[0303] The above method, wherein at least one of the other two layers is a coextruded layer coextruded with six or more other layers.

[0304] The above method, wherein at least one of the other two layers is a coextruded layer coextruded with seven or more other layers.

[0305] The above method, wherein at least one of the other two layers is a coextruded layer coextruded with eight or more other layers.

[0306] The above method, wherein at least one of the other two layers is a coextruded layer coextruded with nine or more other layers.

[0307] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with two or more other layers.

[0308] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with three or more other layers.

[0309] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with four or more other layers.

[0310] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with five or more other layers.

[0311] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with six or more other layers.

[0312] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with seven or more other layers.

[0313] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with eight or more other layers.

[0314] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with nine or more other layers.

[0315] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with two or more other layers.

[0316] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with three or more other layers.

[0317] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with four or more other layers.

[0318] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with five or more other layers.

[0319] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with six or more other layers.

[0320] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with seven or more other layers.

[0321] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with eight or more other layers.

[0322] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with nine or more other layers.

[0323] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with two or more other layers.

[0324] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with three or more other layers.

[0325] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with four or more other layers.

[0326] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with five or more other layers.

[0327] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with six or more other layers.

[0328] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with seven or more other layers.

[0329] The method as described above, wherein at least one of the other two layers is a co-extruded layer co-extruded with eight or more other layers.

[0330] The method as described above, wherein at least one of the other two layers is a coextruded layer coextruded with nine or more other layers.

[0331] A battery separator produced by the method as described above.

[0332] A battery separator comprising a multilayer microporous thin film, wherein: a first region comprising two or more layers, most of which contain discontinuous amorphous regions when viewed in the z-direction of the thin film using SEM; a second region comprising at least one layer The battery separator as described above.

[0333] The battery separator as described above, wherein the second region contains two or more layers and an amorphous region with a maximum width of 0.8 microns when viewed in the z-direction of the thin film using SEM.

[0334] The battery separator as described above, wherein the maximum width of the amorphous region is 0.7 microns.

[0335] The battery separator as described above, wherein the maximum width of the amorphous region is 0.6 microns.

[0336] The battery separator as described above, wherein 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more of the amorphous regions in the first region are discontinuous.

[0337] The battery separator as described above, wherein at least one of the first and second regions contains one or more layers containing a polyolefin.

[0338] The battery separator as described above, wherein the first region contains at least one layer containing polyethylene, and the second region contains at least one layer containing polypropylene.

[0339] The battery separator as described above, wherein at least one of the first and second regions contains a coextruded two-layer, three-layer, or multilayer thin film.

[0340] The above battery separator, wherein the first region comprises a coextruded two-layer, three-layer or multi-layer thin film.

[0341] The above battery separator, wherein the first region and the second region each comprise a coextruded two-layer, three-layer or multi-layer thin film.

[0342] The above battery separator, wherein the first region, the second region and the third region of the microporous multi-layer battery separator each comprise a coextruded two-layer, three-layer or multi-layer thin film.

[0343] The above battery separator, wherein at least one of the second and third regions of the microporous multi-layer battery separator comprises a coextruded two-layer, three-layer or multi-layer thin film.

[0344] The above battery separator, wherein the second region comprises a coextruded two-layer, three-layer or multi-layer thin film.

[0345] The above battery separator, wherein the third region comprises a coextruded two-layer, three-layer or multi-layer thin film.

[0346] A battery separator comprising a multi-layer microporous thin film having an average dielectric breakdown value (V) higher than that of a three-layer microporous thin film having the same thickness, Gurley and / or porosity as the multi-layer microporous thin film.

[0347] The above battery separator, comprising a multi-layer microporous thin film having an average dielectric breakdown value (V) 1-35% higher than that of a three-layer microporous thin film having the same thickness, Gurley and / or porosity as the multi-layer microporous thin film.

[0348] The above battery separator, comprising a multi-layer microporous thin film having an average dielectric breakdown value (V) 5-35% higher than that of a three-layer microporous thin film having the same thickness, Gurley and / or porosity as the multi-layer microporous thin film.

[0349] The above battery separator comprising a multilayer microporous thin film having an average dielectric breakdown value (V) 10 to 35% higher than that of a three-layer microporous thin film having the same thickness, Gurley and / or porosity.

[0350] The above battery separator comprising a multilayer microporous thin film having an average dielectric breakdown value (V) 15 to 35% higher than that of a three-layer microporous thin film having the same thickness, Gurley and / or porosity.

[0351] Having an average dielectric breakdown value (V) 20 to 35% higher than that of a three-layer microporous thin film having the same thickness, Gurley, and / or porosity for the above battery separator comprising a multilayer microporous thin film.

[0352] The above battery separator wherein the minimum dielectric breakdown value of the multilayer microporous thin film is higher than that of a three-layer microporous thin film having the same thickness, Gurley, and / or porosity, for example, 3 to 20% higher, 5 to 15% higher, or 10 to 15% higher.

[0353] The above battery separator wherein the minimum dielectric breakdown value of the multilayer microporous thin film is higher than that of a three-layer microporous thin film having the same thickness, Gurley, and / or porosity, for example, 3 to 20% higher, 5 to 15% higher, or 10 to 15% higher.

[0354] The above battery separator wherein the minimum dielectric breakdown value of the multilayer microporous thin film is higher than that of a three-layer microporous thin film having the same thickness, Gurley, and / or porosity, for example, 3 to 20% higher, 5 to 15% higher, or 10 to 15% higher.

[0355] The minimum dielectric breakdown value of the multilayer microporous film is higher than that of a three-layer microporous film having the same thickness, Gurley, and / or porosity as the multilayer microporous film, for example, 3 to 20% higher, 5 to 15% higher, or 10 to 15% higher, the above-described battery separator.

[0356] The minimum dielectric breakdown value of the multilayer microporous film is higher than that of a three-layer microporous film having the same thickness, Gurley, and / or porosity as the multilayer microporous film, for example, 3 to 20% higher, 5 to 15% higher, or 10 to 15% higher, the above-described battery separator.

[0357] The minimum dielectric breakdown value of the multilayer microporous film is higher than that of a three-layer microporous film having the same thickness, Gurley, and / or porosity as the multilayer microporous film, for example, 3 to 20% higher, 5 to 15% higher, or 10 to 15% higher, the above-described battery separator.

[0358] Nine or more layers are present in the multilayer microporous film, the above-described battery separator.

[0359] Nine or more layers are present in the multilayer microporous film, the above-described battery separator.

[0360] Twelve or more layers are present in the multilayer microporous film, the above-described battery separator.

[0361] Twelve or more layers are present in the multilayer microporous film, the above-described battery separator.

[0362] Fifteen or more layers are present in the multilayer microporous film, the above-described battery separator.

[0363] Fifteen or more layers are present in the multilayer microporous film, the above-described battery separator.

[0364] Eighteen or more layers are present in the multilayer microporous film, the above-described battery separator.

[0365] The above battery separator in which more than 18 layers are present in the multilayer microporous film.

[0366] The above battery separator in which more than 21 layers are present in the multilayer microporous film.

[0367] The above battery separator in which more than 21 layers are present in the multilayer microporous film.

[0368] The above battery separator in which more than 24 layers are present in the multilayer microporous film.

[0369] The above battery separator in which more than 24 layers are present in the multilayer microporous film.

[0370] The above battery separator in which more than 27 layers are present in the multilayer microporous film.

[0371] The above battery separator in which more than 27 layers are present in the multilayer microporous film.

[0372] The above battery separator in which more than 30 layers are present in the multilayer microporous film.

[0373] The above battery separator in which more than 30 layers are present in the multilayer microporous film.

[0374] The above battery separator in which at least one of the layers of the multilayer microporous film contains a polyolefin.

[0375] The above battery separator in which at least one of the layers of the multilayer microporous film contains a polyolefin or a polyolefin blend.

[0376] The above battery separator in which at least one of the layers of the multilayer microporous film contains polyethylene or a polyethylene blend.

[0377] The above-described battery separator, wherein at least one of the layers of the multilayer microporous thin film contains polyethylene or a polyethylene blend.

[0378] The above-described battery separator, wherein at least one of the layers of the multilayer microporous thin film contains polypropylene or a polypropylene blend.

[0379] The above-described battery separator, wherein at least one of the layers of the multilayer microporous thin film contains polypropylene or a polypropylene blend.

[0380] The above-described battery separator, wherein at least one of the layers of the multilayer microporous thin film contains polypropylene or a polypropylene blend, and at least one of the layers contains polyethylene or a polyethylene blend.

[0381] The multilayer microporous thin film comprises: a first region including two or more layers that contain polypropylene and mostly discontinuous amorphous regions when viewed in the z-direction of the thin film using SEM; a second region including at least one layer and the above-described battery separator. The multilayer microporous thin film comprises: a first region including two or more layers that contain polypropylene and mostly discontinuous amorphous regions when viewed in the z-direction of the thin film using SEM, and a second region including at least one layer and the above-described battery separator.

[0382] The multilayer microporous thin film comprises: a first region including two or more layers that contain polypropylene and mostly discontinuous amorphous regions when viewed in the z-direction of the thin film using SEM; a second region including at least one layer; a third region including at least one layer The above battery separator including A multilayer microporous film comprising: A first region comprising two or more layers, where when the film is viewed in the z-direction using SEM, it contains polypropylene and mostly discontinuous amorphous regions; A second region comprising at least one layer; A third region comprising at least one layer The above battery separator including

[0383] A battery separator including a multilayer microporous film that exhibits a peak mercury intrusion value of logarithmic differential intrusion of 5 mL / g or less when measured using mercury intrusion porosimetry.

[0384] The peak mercury intrusion value is such that the logarithmic differential intrusion is 4.5 mL / g or less for the above battery separator.

[0385] The peak mercury intrusion value is such that the logarithmic differential intrusion is 4 mL / g or less for the above battery separator.

[0386] The peak mercury intrusion value is such that the logarithmic differential intrusion is 3.5 mL / g or less for the above battery separator.

[0387] A battery separator including a multilayer microporous film having a MacMilan number greater than 5.

[0388] The MacMilan number is greater than 5.5 for the above battery separator.

[0389] The MacMilan number is greater than 6 for the above battery separator.

[0390] The MacMilan number is greater than 7 for the above battery separator.

[0391] The MacMilan number is greater than 7.5 for the above battery separator.

[0392] The MacMilan number is greater than 8 for the above battery separator.

[0393] The above battery separator having a MacMilan number greater than 9.

[0394] The above battery separator having a MacMilan number greater than 10.

[0395] A battery separator comprising a multilayer microporous thin film having a tortuosity value of 1.6 or more.

[0396] The above battery separator having a tortuosity value of 1.7 or more.

[0397] The above battery separator having a tortuosity value of 2.0 or more.

[0398] A battery separator comprising a multilayer microporous thin film having a pin removal force of less than 50 N.

[0399] The above battery separator having a pin removal force of less than 40 N.

[0400] The above battery separator having a pin removal force of less than 30 N.

[0401] The above battery separator having a pin removal force of less than 20 N.

[0402] The above battery separator having a pin removal force of less than 15 N.

[0403] The above battery separator having a pin removal force of less than 10 N.

[0404] A first region including two or more layers; A second region including two or more layers on a first surface of the first region; A third region including two or more layers on a surface of the first region opposite to the first surface A battery separator comprising a multilayer microporous thin film including: At least one of the first, second, or third regions contains PE and has a crystallinity lower than that of the PE-containing layer of the three-layer microporous thin film when measured by DSC, where the three-layer microporous thin film has the same thickness as the multilayer microporous thin film, the above battery separator.

[0405] The above battery separator with a crystallinity 1 - 20% lower.

[0406] The above battery separator with a crystallinity 1 - 17% lower.

[0407] The above battery separator with a crystallinity 1 - 10% lower.

[0408] The above battery separator with a crystallinity 1 - 5% lower.

[0409] The battery separator includes a multilayer microporous thin film containing at least two regions each including at least two micro-layers or sub-layers and has a mixed intrusion (N) value exceeding 380 N.

[0410] The above battery separator with a mixed intrusion (N) value exceeding 400 N.

[0411] The above battery separator with a mixed intrusion (N) value exceeding 450 N.

[0412] The above battery separator with a mixed intrusion (N) value exceeding 500 N.

[0413] The above battery separator with a mixed intrusion (N) value exceeding 550 N.

[0414] The above battery separator with a mixed intrusion (N) value exceeding 600 N.

[0415] The above battery separator with a mixed intrusion (N) value exceeding 650 N.

[0416] The above battery separator with a mixed intrusion (N) value exceeding 700 N.

[0417] A battery separator including a multilayer microporous thin film having an electrical resistance of 2.0 or less.

[0418] The above battery separator with an electrical resistance of 1.7 or less.

[0419] The above battery separator with an electrical resistance of 1.6 or less.

[0420] The above battery separator with an electrical resistance of 1.5 or less.

[0421] The above battery separator with an electrical resistance of 1.4 or less.

[0422] The above battery separator with an electrical resistance of 1.3 or less.

[0423] The above battery separator with an electrical resistance of 1.2 or less.

[0424] The above battery separator with an electrical resistance of 1.1 or less.

[0425] The above battery separator with an electrical resistance of 1.0 or less.

[0426] A battery separator including a multilayer microporous thin film including a region, including two or more layers and including polyethylene in one or more of the above layers, when this region is tested by the machine learning test described in this specification, the following: W T x'-4 or W T x'≧-2.654 The above battery separator for which the following is satisfied.

[0427] The following: W T x'≧1.3 or W T x'≧2 The above battery separator for which the following is satisfied.

[0428] A battery separator comprising a multilayer microporous thin film including a region, comprising two or more layers and polyethylene in one or more of the above layers, when this region is tested by the machine learning tests described herein, the following: W T x' ≧ -5 or W T x' ≧ -3 is satisfied, the above battery separator.

[0429] The following: W T x' ≧ 0 or W T x' ≧ 3 is satisfied, the above battery separator.

[0430] A battery separator comprising a microporous multilayer thin film having a lower standard deviation value with respect to dielectric breakdown than a three-layer microporous thin film having the same thickness, Gurley, and / or porosity as the multilayer microporous thin film.

[0431] The above battery separator, wherein the standard deviation value is 10 - 60% lower.

[0432] The above battery separator, wherein the standard deviation value is 10 - 40% lower.

[0433] The above battery separator, wherein the standard deviation value is 10 - 20% lower.

[0434] A battery separator having at least one multilayer microporous membrane or thin film having at least two regions or sub-layers each including at least two micro-layers, wherein the multilayer film has or exhibits at least one of the following: (a) A mixed intrusion (N) value exceeding 380 N; (b) A mixed intrusion (N) value exceeding 600 N; (c) A degree of bending of 1.8 or more; (d) An average breakdown voltage (V) that is 1 - 35% higher than that of a three - layer microporous thin film having the same thickness, Gurley, and / or porosity as the multilayer microporous thin film; (e) A minimum breakdown voltage (V) that is 3 - 20% higher than that of a three - layer microporous film or thin film having the same thickness, Gurley, and / or porosity as the multilayer microporous film; (f) Having a standard deviation value of breakdown voltage that is 10 - 60% lower than that of a three - layer microporous film or thin film having the same thickness, Gurley, and / or porosity as the multilayer microporous film; (g) Passing the nail penetration test; (h) Having at least one micro - layer containing PO, PP, and / or PE and an elastomer; (i) Having at least one micro - layer containing a siloxane; (j) Having at least one micro - layer containing PP and an elastomer; (k) Having at least one micro - layer containing a copolymer (l) Having at least one micro - layer containing PP and a copolymer; (m) Having at least two micro - layers containing different resins or resin blends; (n) When one of the above regions contains polypropylene in one or more of the micro - layers, when this region is tested according to the machine - learning test described herein, the following: W T x'≧ - 5 or W T x'≧ - 3; is satisfied (o) When one of the above regions contains polypropylene in one or more of the micro - layers, when this region is tested according to the machine - learning test described herein, the following: W T x'≧0 or W T x'≧3; is satisfied When one of the above regions contains polyethylene in one or more of the micro-layers, when this region is tested according to the machine learning tests described herein: W T x' ≥ -4 or W T x' ≥ -2.654; is satisfied (q) When one of the above regions contains polyethylene in one or more of the micro-layers, when this region is tested according to the machine learning tests described herein: W T x' ≥ 1.3 or W T x' ≥ 2; is satisfied (r) When one of the above regions contains polyethylene in one or more of the micro-layers, when this region is tested according to the machine learning tests described herein: W T x' ≥ -4 or W T x' ≥ -2; is satisfied (s) When one of the above regions contains polyethylene in one or more of the micro-layers, when this region is tested according to the machine learning tests described herein: W T x' ≥ 2 or W T x' ≥ 4; is satisfied (t) When one of the above regions contains PE and has a crystallinity that is 1 - 20% lower, as measured by DSC, than that of the PE-containing layer of a three-layer microporous membrane or thin film having the same thickness, Gurley, and / or porosity as the multi-layer microporous thin film; (u) The microporous multi-layer film or thin film has 30 - 100 micro-layers or more; (v) At least one of the micro-layers contains lithium stearate; (w) The multi-layer microporous thin film exhibits a reduced MD or TD tear strength; (x) At least one of the micro-layers contains PE beads; (y) having pin removal of less than 50 N; (z) showing reduced contact with pins; (aa) having reduced MD or TD tear strength; (bb) may be a precursor for at least one of transverse (TD) stretching, calendering, and pore filling The above method.

[0435] The above battery separator, wherein at least one surface of the battery separator is coated.

[0436] The above battery separator, wherein both surfaces of the battery separator are coated.

[0437] The above battery separator, wherein at least one surface is coated with a ceramic film.

[0438] A novel or improved membrane, separator membrane, separator, battery separator, lithium secondary battery separator, multilayer membrane, multilayer separator membrane, multilayer separator, multilayer battery separator, multilayer lithium secondary battery separator, and / or multilayer battery separator, a novel or improved battery, capacitor, fuel cell, lithium battery, lithium ion battery, lithium secondary battery, and / or lithium ion secondary battery, and / or a method of fabricating and / or using such a membrane, separator membrane, separator, battery separator, lithium secondary battery separator, battery, capacitor, fuel cell, lithium battery, lithium ion battery, lithium secondary battery, and / or lithium ion secondary battery, and / or a device, vehicle or product containing the same; A novel or improved membrane layer, membrane or separator membrane, a battery separator comprising such a membrane, and / or a related method; A novel or improved porous polymer membrane or separator membrane, a battery separator comprising such a membrane, and / or a related method; Novel or improved microporous polyolefin membranes or separator membranes, micro-layer membranes, multi-layer membranes including one or more micro-layers or nano-layer membranes, battery separators including such membranes, and / or related methods; One or more novel or improved outer layers and / or inner layers, micro-layer membranes, novel, optimized, or improved microporous stretched polymer membranes or separator membranes having multi-layered microporous membranes or separator membranes with outer and inner layers, some of such layers or sub-layers being produced by co-extrusion and then laminated together to form the above novel, optimized, or improved membranes or separator membranes; The layer, micro-layer or nano-layer may include a homopolymer, copolymer, block copolymer, elastomer, and / or polymer blend. The layer, micro-layer or nano-layer may include different or distinct polymers, homopolymers, copolymers, block copolymers, elastomers, and / or polymer blends. Novel or improved methods for producing such membranes, separator membranes, or separators, and / or novel or improved methods for using such membranes, separator membranes or separators, for example, as lithium battery separators; Novel or improved multi-layer and / or micro-layer porous or microporous membranes, separator membranes, separators, composites, electrochemical devices, and / or batteries, and / or methods for producing and / or using such membranes, separators, composites, devices and / or batteries; A novel or improved multi-layered separator membrane, wherein one or more layers of the multi-layer structure are produced in a multi-layer or micro-layer co-extrusion die having a plurality of extruders; and / or A novel or improved membrane, separator membrane, or separator that preferably can demonstrate an improved shutdown, improved strength, improved dielectric strength, and / or reduced tendency to tear, as shown, described, or claimed herein.

[0439] Various embodiments of the invention are described in achieving various objects of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the invention. Many changes and modifications will be readily apparent to those skilled in the art without departing from the spirit and scope of the invention.

[0440] The invention may be embodied without departing from its spirit and essential characteristics, and thus, reference should be made to the appended claims rather than the foregoing specification as indicating the scope of the invention. Components that may be used to implement the disclosed methods and systems are disclosed. These and other components are disclosed herein, and although combinations, subsets, interactions, groups, etc. of these components may not be explicitly disclosed when each of their various individual and collective combinations and permutations are not explicitly disclosed, when disclosed, each is understood to be specifically contemplated for all methods and systems and described herein. This applies to all aspects of this application, including but not limited to the steps in the disclosed methods. Thus, when there are various additional steps that may be implemented, it is understood that each of these additional steps may be implemented by any specific embodiment or combination of embodiments of the disclosed methods.

[0441] The detailed description of the structures and methods presented above is for illustrative purposes only. Using examples, exemplary embodiments including the best mode are disclosed, and any person skilled in the art will be able to implement the present invention, including making and using any device or system and implementing any incorporated method. These examples are not intended to be exclusive or to limit the invention to the exact steps and / or forms disclosed, and many changes and modifications are possible in light of the above teachings. The features described herein may be combined in any combination. The steps of the methods described herein may be performed in any physically possible order. The patentable scope of the present invention is defined by the appended claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims when they have structural elements that do not differ from the literal language of the claims or when they include equivalent structural elements that do not substantially differ from the literal language of the claims.

[0442] The compositions and methods of the appended claims are not limited in scope by the specific compositions and methods described herein. In addition to those shown and described herein, various changes in the compositions and methods are intended to be within the scope of the appended claims. Further, although only certain representative compositions and method steps disclosed herein are specifically described, other combinations of such compositions and method steps are also intended to be within the scope of the appended claims, even if not specifically enumerated. Accordingly, while a combination of steps, elements, components, or ingredients may be explicitly recited herein or below, other combinations of steps, elements, components, or ingredients are included even if not explicitly described.

[0443] As used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" or "approximately" one particular value and / or / to "about" or "approximately" another particular value. When such a range is expressed, other embodiments include from one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," the particular value is understood to form another embodiment. It is further understood that each of the endpoints of a range is significant both in relation to the other endpoint and independently of the other endpoint. The terms "optional" or "optionally" mean that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0444] Throughout the detailed description and the claims of this specification, the word "comprise" and variations such as "comprising" and "comprises" mean "include but not limited to," and are not intended to (e.g.,) exclude other additives, components, integer values, or steps. The terms "consisting essentially of" and "consisting of" may be used in place of "comprising" and "including" to impart more specific embodiments of the invention, and are also disclosed. The terms "exemplary" or "for example" mean "an example of," and are not intended to convey that the preferred or ideal embodiments are being shown. Similarly, "such as" is used for illustrative or exemplary purposes, and not in a limiting sense.

[0445] All numbers representing geometric shapes, dimensions, etc. used in this specification and the claims, other than those noted, should be understood to be at least, and not as an attempt to limit the application of the doctrine of equivalents and the claims, but should be construed in terms of the number of significant figures and the normal rounding approach.

[0446] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed invention pertains. The patent publications and materials listed in this specification are specifically incorporated by reference.

[0447] In addition, the invention disclosed illustratively in this specification may preferably be practiced in the absence of any element not specifically disclosed herein.

Claims

1. A battery separator comprising a multilayer microporous thin film, a first region comprising three or more polyethylene (PE) layers, a second region comprising three or more polypropylene (PP) layers on a first side of the first region, a third region comprising three or more polypropylene (PP) layers on a side of the first region opposite the first side, comprising, the first region, the second region, and the third region are coextruded dry process films, and at least two of the first region, the second region, and the third region are laminated to each other, and the puncture strength of the separator is 290 gf or more, The PE is a blend of 95% high-density polyethylene having a melt index of 0.25 to 0.5 g / 10 min at 2.16 kg and 190 °C and a density range of 0.955 to 0.966 g / cm ３ and 5% mLLDPE (metallocene linear low-density polyethylene), and is a battery separator.

2. The battery separator according to claim 1, wherein the first region, the second region, and the third region each include a layer having a thickness of less than 4 μm and having a mixed intrusion (N) value exceeding 380 N.

3. The battery separator according to claim 1, wherein each of the three or more polyethylene (PE) layers in the first region and each of the three or more polypropylene (PP) layers in each of the second region and the third region have a thickness of 0.1 to 5 μm.

4. The battery separator according to claim 1, wherein each of the three or more polyethylene (PE) layers in the first region and each of the three or more polypropylene (PP) layers in each of the second region and the third region are coextruded dry process polyolefin layers.

5. The battery separator according to claim 1, having an average dielectric breakdown value (V) of 1504 to 2060.

6. The battery separator according to claim 1, wherein when measured using mercury intrusion porosimetry, the multilayer microporous thin film exhibits a peak mercury intrusion value of logarithmic differential intrusion of 5 mL / g or less.

7. The battery separator according to claim 1, having a MacMullin number greater than 5.

8. The battery separator according to claim 1, having a degree of bend value of 1.6 or more.

9. The battery separator according to claim 1, having a pin removal force of less than 50 N.

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