Battery separator and method of manufacturing the same, dry film for battery separator, lithium battery

Abstract

A battery separator comprising: a microporous polymeric film; and an optional coating on at least one side of the microporous polymeric film, wherein at least one of the microporous polymeric film and the optional coating comprises an additive selected from the group consisting of: a lubricant, a plasticizer, a nucleating agent, a shrinkage reducing agent, and a surfactant; or at least one of the microporous polymeric film and the optional coating comprises an electrolyte additive; or at least one of the microporous polymeric film and the first coating comprises a polysiloxane having a weight average molecular weight of between 500,000 and 1,000,000. According to the present invention, pin removal in the separator product can be improved, battery life can be extended, and strength can be increased while balancing electrochemical cell performance.

Description

[0001] This application is a divisional application. The original PCT application priority date was November 7, 2016; the original international application date was November 7, 2017; the original international application number was PCT / US2017 / 060377; the date of entry into the Chinese national phase was July 4, 2019, and the Chinese application number is 201780082294.9; the original invention title was "Battery Separator".

[0002] Priority Statement

[0003] This application claims priority and benefit to U.S. Provisional Patent Application No. 62 / 418,435, filed November 7, 2016, pursuant to 35 U.S. SC § 119(e), the entire contents of which are incorporated herein by reference. Technical Field

[0004] According to at least selected embodiments, this application or invention is committed to additives for improving battery performance, improved films containing additives, improved battery separators, and / or improved batteries, and / or improved or related methods of manufacturing and / or using them. According to at least specific embodiments, this application or invention is committed to films containing additives, separator films, and / or battery separators, and / or methods of manufacturing and / or using such films, separator films, and / or battery separators. According to at least particular embodiments, this application or invention is committed to adding additives to microporous films or separator films for secondary lithium batteries (e.g., secondary lithium-ion batteries), improved battery separators, and / or related methods. In some embodiments, the film may contain additives that improve performance in battery chemistry (e.g., in lithium-ion batteries). In other selected embodiments, the film may contain additives that improve needle removal performance, such as siloxanes or lithium stearate. In other specific embodiments, the invention may also relate to methods of preparing such films or separator films and methods of using such films or separator films, for example, as 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, and batteries, as well as methods for manufacturing such membranes, separators, composites, devices, and / or batteries. According to at least specific selected embodiments, the invention is directed to novel or improved separator membranes containing additives or elastomers. Improved membranes may preferably exhibit improved shut-off, improved strength, improved dielectric breakdown strength, and / or reduced cracking tendency. According to at least specific selected embodiments, this application or invention is directed to battery separators having a microporous polymer film or membrane and an optional coating layer on one side of the microporous polymer film, wherein at least one of the microporous polymer film and the optional coating contains an additive. Additives may be selected from lubricants, plasticizers, nucleating agents, shrinkage reducers, surfactants, SEI modifiers, cathodic protection agents, flame retardant additives, LiPF6 salt stabilizers, overcharge protectors, aluminum corrosion inhibitors, lithium deposition agents or modifiers or solvation enhancers, aluminum corrosion inhibitors, wetting agents, viscosity modifiers, friction reducers, COF reducers, needle removal force weakeners, copolymers, block copolymers, and / or combinations thereof. Furthermore, this document describes batteries (including primary or secondary lithium-ion batteries) comprising one or more of the described films, membranes, coatings, and / or separators. Methods for manufacturing the films, membranes, coatings, and / or battery separators are also described.According to at least a particular embodiment, this application or invention is committed to an improved or new battery separator having at least one of the following: enhanced puncture strength, reduced needle removal force, improved electrolyte wettability and increased pore size, and a microporous polymer film having an optional coating layer on at least one side thereof; a battery separator having at least one of an optional coating layer and a microporous polymer film, comprising an additive selected from lubricants, surfactants, nucleating agents, shrinkage agents and / or plasticizers therein and / or on the microporous polymer film having the additive primarily present in at least one surface region of the film, or present throughout the film, in a single surface region of the film, in a first surface region of the film and in a second surface region of the film opposite to the first surface region; a coating applied to the surface of the microporous polymer film, the coating being applied only to one surface of the microporous polymer film, applied to a first side of the microporous polymer film, while another coating is applied to a second side of the microporous polymer film opposite to the first side, and / or combinations thereof. According to at least one possible preferred embodiment, the microporous polymer film or membrane is a microporous polyolefin film, such as a dry-stretched process film, such as a single-layer dry-process film, a two-layer dry-process film, or a multi-layer dry-process film. Furthermore, according to at least one possible preferred embodiment, one, two, three, four, or all five different types of additives may be added to the film, coating, or separator, or a single additive may be added that functions as one, two, three, four, or all five different types of additives; for example, an additive that is both a lubricant and a surfactant may be added to or on it. Background Technology

[0005] Methods for improving battery separators and batteries have been discussed in this art. Many of these methods for improving battery separators focus on manipulating the polymer by controlling the extrusion process (i.e., co-extrusion or changing the blow-up ratio) or by combining various stretching techniques such as biaxial stretching. Other methods for improving battery separators include controlling the type of resin used, such as high molecular weight or low molecular weight resins.

[0006] As separators become thinner and / or their pore sizes increase to meet market demands, reducing surface friction on polypropylene microporous membranes to facilitate needle removal during battery core manufacturing becomes increasingly challenging. U.S. Patent No. 6,692,867 describes the use of calcium stearate to improve needle removal. While calcium stearate has been used, it tends to “bloom” or “snow” during high-temperature extrusion, contaminating equipment. Therefore, additives resistant to higher temperatures are needed. Furthermore, although the amount of calcium stearate added in the past was sufficient to improve needle removal in thicker, older separator products, it is insufficient for at least some newer separators that are being manufactured increasingly thinner to meet market demands, and it cannot be added in sufficiently high amounts without undesirable increases in “bloom” or “snow.” Therefore, a new alternative is needed to improve needle removal in at least certain separator products.

[0007] One of the key aspects of improving batteries and enabling the commercialization of future battery chemistry and technology is incorporating electrolyte additives into the electrolyte system. By including electrolyte additives, it is possible to stabilize high-voltage battery operation and extend battery life, for example. Some commonly used additives include borates, ethylene carbonate, and many other materials. These are typically added to the liquid electrolyte solution before battery manufacturing. However, this makes it difficult to ensure reproducible batch production, and the shelf life of electrolytes with additives can be very short. Electrolyte solutions should be mixed and used within a short period of time. Therefore, a new method for providing electrolyte additives without these problems is needed.

[0008] Although improvements to the mechanical strength of membranes and working compositions optimized for use in high-voltage systems have been mentioned many times in the art, new methods are still needed to improve strength while balancing the performance of electrochemical cells. Summary of the Invention

[0009] According to at least selected embodiments, this application or invention can address the aforementioned needs, desired improvements, difficulties, or problems, and / or can provide new and / or improved additives for improved battery performance, improved additive-containing membranes, improved battery separators, and / or improved batteries, and / or improved or related methods of manufacturing and / or using them. According to at least specific embodiments, this application or invention is directed to additive-containing membranes, separator membranes, and / or battery separators, and / or methods of manufacturing and / or using such membranes, separator membranes, and / or battery separators. According to at least particular embodiments, this application or invention is directed to incorporating additives into microporous membranes or separator membranes for secondary lithium batteries (such as secondary lithium-ion batteries), improved battery separators, and / or related methods. In some embodiments, the membrane may contain additives that improve performance in battery chemistry (e.g., in lithium-ion batteries). In other selected embodiments, the membrane may contain additives that improve needle removal performance, such as siloxanes or lithium stearate. In other specific embodiments, the invention may also relate to methods of manufacturing such membranes or separators and methods of using such membranes or separators, for example, as lithium-ion battery separators. According to at least selected embodiments, this application or invention is dedicated to new or improved porous membranes, separators, separators, dry-process separators, composites, electrochemical devices, batteries, and methods of manufacturing such membranes, separators, composites, devices, and / or batteries. According to at least specific selected embodiments, the invention is dedicated to new or improved separators containing additives or elastomers. Improved membranes may preferably exhibit improved shut-off, improved strength, improved dielectric breakdown strength, and / or reduced cracking tendency. According to at least specific selected embodiments, this application or invention is dedicated to battery separators having a microporous polymer film or membrane and having an optional coating layer on at least one side of the microporous polymer film, wherein at least one of the microporous polymer film and the optional coating contains an additive. Additives may be selected from lubricants, plasticizers, nucleating agents, shrinkage reducers, surfactants, SEI modifiers, cathodic protection agents, flame retardant additives, LiPF6 salt stabilizers, overcharge protectors, aluminum corrosion inhibitors, lithium deposition agents or modifiers, or solvation enhancers, aluminum corrosion inhibitors, wetting agents, viscosity modifiers, friction reducers, COF reducers, needle removal force weakeners, copolymers, block copolymers, and / or combinations thereof. Furthermore, this document also describes batteries (including primary or secondary lithium-ion batteries) comprising one or more of the described films, membranes, coatings, and / or separators. Methods for manufacturing the films, membranes, coatings, and / or battery separators are also described.According to at least a particular embodiment, this application or invention is committed to an improved or new battery separator having at least one of the following: enhanced puncture strength, reduced needle removal force, improved electrolyte wettability and increased pore size, and a microporous polymer film having an optional coating layer on at least one side thereof; a battery separator having at least one of an optional coating and a microporous polymer film, comprising an additive selected from lubricants, surfactants, nucleating agents, shrinkage agents and / or plasticizers therein and / or on the microporous polymer film having the additive primarily present in at least one surface region of the film, or present throughout the film, in a single surface region of the film, in a first surface region of the film and in a second surface region of the film opposite to the first surface region; a coating applied to the surface of the microporous polymer film, the coating being applied only to one surface of the microporous polymer film, applied to a first side of the microporous polymer film, while another coating is applied to a second side of the microporous polymer film opposite to the first side, and / or combinations thereof. According to at least one possible preferred embodiment, the microporous polymer film or membrane is a microporous polyolefin film, such as a dry-stretched process film, such as a single-layer dry-process film, a two-layer dry-process film, or a multi-layer dry-process film. Furthermore, according to at least one possible preferred embodiment, one, two, three, four, or all five different types of additives may be added to the film, coating, or separator, or a single additive may be added that functions as one, two, three, four, or all five different types of additives; for example, an additive that is both a lubricant and a surfactant may be added to or on it.

[0010] According to at least selected embodiments, aspects, or purposes, this application or invention is dedicated to improved additive-containing membranes, improved battery separators and / or improved batteries, and / or improved or related methods of manufacturing and / or using them.

[0011] At least in certain embodiments, this application or invention is directed to polyolefin films, polyolefin separator films, and / or polyolefin film battery separators containing additives, and / or methods of manufacturing and / or using such polyolefin films, separator films, and / or battery separators. According to at least certain selected embodiments, this application or invention is directed to battery separators having a microporous polyolefin film or membrane and having an optional coating on at least one side of the microporous polyolefin film, wherein at least one of the microporous film and the optional coating contains an additive. The additive may be a self-lubricant, plasticizer, nucleating agent, shrinkage reducer, surfactant, SEI modifier, cathodic protection agent, flame retardant additive, LiPF6 salt stabilizer, overcharge protectant, aluminum corrosion inhibitor, lithium deposition agent or modifier, or solvation enhancer, aluminum corrosion inhibitor, wetting agent, viscosity modifier, friction reducer, COF reducer, needle removal force reducer, copolymer, block copolymer, and / or combinations thereof. Furthermore, batteries (including primary or secondary lithium-ion batteries) comprising one or more of the described polyolefin films, membranes, coatings, and / or separators are also described herein. Methods for manufacturing polyolefin films, membranes, coatings, and / or battery separators are also described. According to at least particular embodiments, this application or invention is committed to improved or novel polyolefin film battery separators having at least one of the following: a microporous polyolefin film with enhanced puncture strength, reduced needle removal force, improved electrolyte wettability, and increased pore size, having an optional coating layer on at least one side thereof; a battery separator having at least one of an optional coating and a microporous polyolefin film, containing within and / or on an additive selected from lubricants, surfactants, nucleating agents, shrinkage reducers, and / or plasticizers, the microporous polyolefin film having the additive primarily present in at least one surface region of the film, or present throughout the film, in a single surface region of the film, in a first surface region of the film, and in a second surface region of the film opposite to the first surface region; a coating applied to the surface of the microporous film, the coating being applied only to one surface of the microporous film, applied to a first side of the microporous film, while another coating is applied to a second side of the microporous film opposite to the first side, and / or combinations thereof. According to at least one possible preferred embodiment, the microporous polymer film or membrane is a microporous polyolefin dry-stretch process film, such as a single-layer dry-process film, a two-layer dry-process film, or a multi-layer dry-process film. Furthermore, according to at least one possible preferred embodiment, one, two, three, four, or all five different types of additives may be added to the film, coating, or separator, or a single additive may be added that functions as one, two, three, four, or all five different types of additives; for example, an additive that is both a lubricant and a surfactant may be added to or on it.

[0012] In one aspect, this paper describes battery separators. In particular, this paper describes battery separators having at least one of, for example, increased puncture strength, reduced needle removal force, improved electrolyte wettability, and increased pore size.

[0013] The battery separator comprises, consists of, or is substantially composed of: a microporous polymer film and an optional coating on at least one side of the microporous polymer film. In the battery separator, at least one of the optional coating and the microporous polymer film contains an additive selected from lubricants, surfactants, nucleating agents, shrinkage reducing agents, and plasticizers.

[0014] In embodiments where the additive is present in the microporous polymer film, the additive may be primarily present in at least one surface region of the film or may be present throughout the entire film. In some embodiments, the additive may be present in a single surface region of the film. In other embodiments, the additive may be present in a first surface region of the film and a second surface region of the film opposite to the first surface region.

[0015] In some embodiments, the additive may be in a coating applied to the surface of the microporous polymer film. In some embodiments, the coating may be applied to only one surface of the microporous polymer film. In other embodiments, the coating may be applied to a first surface of the microporous polymer film, and another coating may be applied to a second surface of the microporous polymer film opposite the first surface.

[0016] The microporous polymer film or membrane can be a nonwoven stretched film or membrane, such as a single-layer dry process film, a double-layer dry process film or a multilayer dry process film (and may have a layer, coating or treatment applied to at least one side thereof).

[0017] One, two, three, four, or all five different types of additives may be added, or a single additive may be added that functions as one, two, three, four, or all five different types of additives. For example, an additive that is both a lubricant and a surfactant. Additives may be present in amounts of 10,000 to 200,000 ppm, 10,000 to 100,000 ppm, 10,000 to 60,000 ppm, or 10,000 to 30,000 ppm.

[0018] In some embodiments, the additive is a lubricant. It may also be at least one of a surfactant, nucleating agent, shrinkage reducer, and plasticizer. The lubricant may be a water-soluble lubricant. The lubricant may also be a lubricant with a melting point higher than 220°C, 230°C, or 240°C. In some embodiments, the lubricant is a fatty acid salt having at least one of the following properties: it is water-soluble or has a melting point higher than 220°C, 230°C, or 240°C. In some embodiments, the fatty acid salt has both of these properties. In some embodiments, the fatty acid salt is selected from lithium stearate, sodium stearate, and potassium stearate. In some embodiments, the lubricant is a polysiloxane, including ultra-high molecular weight polysiloxanes.

[0019] In another embodiment, this document describes another type of battery separator. This battery separator contains an electrolyte additive that can be released from the separator into the electrolyte when the separator is incorporated into a battery (particularly a lithium-ion battery).

[0020] The battery separator comprises, consists of, or is substantially composed of: a microporous polymer film and an optional coating on at least one side of the microporous polymer film. In the battery separator, at least one of the optional coating and the microporous polymer film contains an electrolyte additive.

[0021] In embodiments where the electrolyte additive is present in the microporous polymer film, the additive may be primarily present in at least one surface region of the film or may be present throughout the entire film. In some embodiments, the additive may be present in a single surface region of the film. In other embodiments, the electrolyte additive may be present in a first surface region of the film and a second surface region of the film opposite to the first surface region.

[0022] In some embodiments, the electrolyte additive may be in a coating applied to the surface of the microporous polymer film. In some embodiments, the coating may be applied to only one surface of the microporous polymer film. In other embodiments, the coating may be applied to a first surface of the microporous polymer film, and another coating may be applied to a second surface of the microporous polymer film opposite the first surface.

[0023] Microporous polymer films or membranes can be blown, cast, or stretched nonwoven polyolefin films or membranes, such as single-layer dry process films, double-layer dry process films, or multilayer dry process films.

[0024] In some embodiments, the electrolyte additive is selected from SEI modifiers, cathodic protection agents, flame retardant additives, LiPF6 salt stabilizers, overcharge protection agents, aluminum corrosion inhibitors, lithium deposition agents or modifiers, or solvation enhancers, aluminum corrosion inhibitors, wetting agents and viscosity modifiers. The amount of electrolyte additive can be 1,000 to 200,000 ppm, 1,000 to 100,000 ppm, 10,000 to 100,000 ppm, 10,000 to 60,000 ppm or 10,000 to 30,000 ppm.

[0025] On the other hand, this document describes a battery (particularly a lithium-ion battery) comprising a separator having additives as described herein. In some embodiments, the battery comprises an electrolyte, and this battery separator exhibits improved electrolyte wettability compared to the same battery separator without at least one additive described herein. In some embodiments, the electrolyte may be a lithium salt in a liquid solvent (e.g., SO2 or SOCl2). In other embodiments, the additive is an electrolyte additive that is released into the electrolyte after battery formation and / or during battery operation.

[0026] On the other hand, this document describes a method for forming the battery separator described herein. The method includes at least one of the following steps: (1) forming a microporous polymer film from a polymer mixture comprising a polymer and an additive, and (2) coating the microporous film with a coating mixture comprising a polymer and an additive. The additive may be any additive mentioned above. In some embodiments, the step of forming the microporous polymer film may comprise, consist of, or substantially consist of: extruding a polymer mixture comprising a polymer and an additive. Attached Figure Description

[0027] Figure 1 This is a box plot of the needle removal force of a battery separator according to some embodiments described herein.

[0028] Figure 2 This is a box plot of the puncture strength of a battery separator according to some embodiments described herein.

[0029] Figure 3 This is a differential capacity diagram of a battery that includes a battery separator according to the control PP and the siloxane-containing embodiments of the present invention.

[0030] Figure 4 This is a diagram showing the cycle of a battery separator according to some embodiments described herein.

[0031] Figure 5 This is a pore size distribution diagram of a battery separator according to some embodiments described herein.

[0032] Figure 6 This is a box plot of the needle removal force of the battery separator based on the control (Celgard 2500) and some embodiments described herein.

[0033] Figure 7 This is a pore size distribution diagram of the battery separator based on the comparison and embodiments described herein.

[0034] Figure 8 It is a DSC coating of Prime Polymer polypropylene with and without 5% lithium stearate.

[0035] Figure 9 This is a diagram showing the cycle of a battery separator according to some embodiments described herein.

[0036] Figure 10 This is a schematic diagram of a battery separator according to some implementation methods, indicating the x, y, and z directions of the battery separator.

[0037] Figures 11 to 17 These are schematic diagrams of specific co-extruded multilayer precursors, films, or separators according to some embodiments described herein. Detailed Implementation

[0038] This application relates to battery separators containing additives and related methods of manufacturing and using them. In some embodiments, the battery separator may contain additives that improve at least one of the following: ease of handling or processing the battery separator, for example, reduced needle removal force, improved electrostatic control, and reduced friction; and performance characteristics of the separator, such as higher puncture strength, greater compatibility and wettability with the electrolyte, and higher overall strength.

[0039] Battery separator

[0040] The battery separator preferably comprises, consists of, or is substantially composed of: (1) a microporous polymer film, and (2) an optional coating on one or more sides or surfaces of the microporous polymer film (the coating may be more than one layer and the coatings on each side may be the same or different, for example, a ceramic coating on only one side, a ceramic coating on one side and a polymer coating on the other side, or a ceramic coating covered by a polymer or adhesive on only one side). In some embodiments of double-sided coating, the coating is applied to a first side of the microporous film and a side of the microporous film opposite to the first side. At least one of the microporous polymer film and the optional coating contains one or more of the additives described herein.

[0041] A battery separator provides physical isolation between the anode and cathode of the battery. In a preferred embodiment, ions can flow through the separator in the battery, but at elevated temperatures, the separator has a shut-off capability, preventing the flow of ions.

[0042] (1) Microporous polymer films

[0043] There are few limitations on the microporous polymer film. In some preferred embodiments, it is microporous and contains one or more polymers. The microporous film contains pores with an average diameter or pore size between 0.01 and 1.0 micrometers, or 0.01 to 0.5 micrometers, preferably 0.01 to 0.08 micrometers, more preferably 0.01 to 0.06 micrometers, and in some embodiments, 0.01 to 0.04, 0.01 to 0.03, or 0.01 to 0.02 micrometers. In some embodiments, the porosity of the microporous polymer film is 20 to 90%, 40 to 80%, or 50 to 70%. Porosity is measured using ASTM D-2873 and is defined as the percentage of void space (e.g., pores) in a region of a porous substrate measured in the processing direction (MD) and transverse direction (TD) of the film. In some embodiments, the microporous polymer membrane has a JIS Gurley value of 50 to 800 seconds; in others, it is 100 to 600 seconds; in still others, the porous JIS Gurley value is 200 to 500 seconds; and in yet another embodiment, it is 200 to 400 seconds or 200 to 300 seconds. The Gurley value is defined herein as the Japanese Industrial Standard (JIS Gurley value) and is measured using an OHKEN permeability tester. The JIS Gurley value is defined in seconds as the time required for 100 cc of air to pass through a one-square-inch membrane at a constant pressure of 4.9 inches of water. In some embodiments, the pores of the microporous polymer membrane are circular (e.g., with a sphericity coefficient of 0.25 to 8.0), elliptical, slit-like, or oval.

[0044] There are few restrictions on the polymers used in the microporous polymer films, and they can be any polymer that does not contradict the objectives described herein. For example, the polymer can be at least one selected from polyolefins, fluorocarbons, polyamides, polyesters, polyacetals (or polyoxymethylene), polysulfides, polyvinyl alcohol, copolymers thereof, and combinations thereof. Polyolefins may include polyethylene (LDPE, LLDPE, HDPE, UHMWPE), polypropylene, polybutene, polymethylpentene, copolymers thereof, and blends thereof. Fluorocarbons may include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), fluorinated ethylene propylene (FEP), ethylene-chlorotrifluoroethylene (ECTFE), ethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), prefluoroalkoxy (PFA) resins, copolymers thereof, and blends thereof. Polyamides may include, but are not limited to: polyamide 6, polyamide 6 / 6, nylon 10 / 10, polyphthalamide (PPA), copolymers thereof, and blends thereof. Polyesters may include polyester terephthalate (PET), polybutylene terephthalate (PBT), poly-1,4-cyclohexanedimethyl terephthalate (PCT), polyethylene naphthalate (PEN), and liquid crystal polymers (LCP). Polysulfides include, but are not limited to, polyphenylene sulfide, polyethylene sulfides, copolymers thereof, and blends thereof. Polyvinyl alcohol includes, but is not limited to, ethylene-vinyl alcohol, copolymers thereof, and blends thereof. In some embodiments, the porous substrate comprises at least one of the following: polyolefins (PO) [e.g., polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), etc.], polyethylene terephthalate (PET), aromatic polyamides, polyvinylidene fluoride (PVDF), including polymers, copolymers, and block polymers thereof.

[0045] In some preferred embodiments, the polymer of the microporous polymer film is a polyolefin, such as polypropylene or polyethylene. In some embodiments, the polyolefin described herein can be an ultra-low molecular weight, low molecular weight, medium molecular weight, high molecular weight, ultra-high molecular weight polyolefin, or any combination thereof. For example, ultra-high molecular weight polyolefins may have a molecular weight of 450,000 (450k) or higher, such as 500k or higher, 650k or higher, 700k or higher, 800k or higher, etc. High molecular weight polyolefins may have a molecular weight of 250k to 450k, such as 250k to 400k, 250k to 350k, or 250k to 300k. Medium molecular weight polyolefins may have a molecular weight of 150k to 250k, such as 150k to 225k, 150k to 200k, 150k to 200k, etc. Low molecular weight polyolefins may have a molecular weight of 100k to 150k, such as 100k to 125k. Ultra-low molecular weight polyolefins can have a molecular weight of less than 100 kJ. These values ​​are weight-average molecular weights. In some embodiments, higher molecular weight polyolefins can be used to improve the strength or other properties of microporous membranes or batteries comprising such microporous membranes as described herein. In some embodiments, lower molecular weight polymers, such as medium, low, or ultra-low molecular weight polymers, may be advantageous. For example, without wishing to be bound by any particular theory, it is believed that the crystallization behavior of lower molecular weight polyolefins can result in microporous membranes as described herein having smaller pores.

[0046] There are no restrictions on the structure of the microporous polymer film, and the film can have any structure that does not contradict the purposes described herein. For example, the film can have a single-layer, double-layer, triple-layer, or multi-layer structure. The thickness of each layer can be 0.1 to 30 micrometers, 0.1 to 25 micrometers, 0.1 to 20 micrometers, 0.1 to 15 micrometers, 1 to 10 micrometers, or 2 to 5 micrometers. These layers can have the same or different thicknesses. A single-layer polymer film as described herein has one polymer-containing layer. A double-layer polymer film as described herein has two polymer-containing layers. A double-layer polymer film can be formed, for example, by co-extruding two potentially identical or different polymer-containing mixtures. In other embodiments, a double-layer polymer film can be formed by separately forming two single-layer polymer films and then laminating them together to form a double-layer structure. A triple-layer polymer film as described herein has three polymer-containing layers. A triple-layer polymer film can be formed, for example, by co-extruding three polymer mixtures, each polymer mixture being the same or different. In alternative embodiments, three different single-layer films can be formed separately, and then these films can be laminated together to form a triple-layer structure. The multilayer structures described herein have two or more layers comprising the same or different polymers or polymer mixtures. In some embodiments, the multilayer structure can be formed by co-extruding four or more different polymer mixtures. In alternative embodiments, four or more monolayer films can be formed individually and laminated together. In other embodiments, two or more co-extruded bilayer, trilayer, or multilayer films can be formed and laminated together. In further embodiments, a co-extruded trilayer film can be formed and laminated with individually formed monolayer, bilayer, trilayer, or multilayer films to form unique multilayer or multilayer co-extruded and laminated structures.

[0047] In other embodiments, the microporous polymer film may be a nonwoven film. As those skilled in the art will understand, nonwoven films are formed by mechanically, thermally, or chemically entangled fibers or filaments (e.g., polymer fibers or filaments).

[0048] In a preferred embodiment, the microporous polymer film is a dry-process microporous polymer film, meaning that the film is formed without the use of solvents. An exemplary dry process is a dry stretching process, which includes, or consists substantially of, the following steps: extruding a polymer to form a non-porous precursor film, and stretching the precursor film (among other things) to form pores. An exemplary dry stretching process is... Dry stretching process. In some embodiments, the extrusion step may include co-extrusion, wherein two or more polymer mixtures that are the same as or different from each other are co-extruded.

[0049] Microporous polymer films may contain the additives described herein throughout the film. In some embodiments, the additives are primarily located in one or more surface regions of the microporous polymer film. The term "surface region" refers to the region comprising the surface (xy) of the microporous polymer film and the depth (z) measured from the same surface of the microporous polymer film. See, for example, Figure 10 The x, y, and z directions of the cube represent the microporous polymer film described herein. The depth of the surface region can be 0.1 to 30 micrometers, 0.1 to 25 micrometers, 0.1 to 20 micrometers, 0.1 to 15 micrometers, 1 to 10 micrometers, or 2 to 5 micrometers. The phrase "primarily in one or more surface regions" means that 90% or more, 95% or more, or 99% or more of the additive is present in one or more surface regions, but not outside of them. In some embodiments, 100% of the additive may be contained in one or more surface regions, and sometimes 80% or more of the additive is present in one or more surface regions, but not outside of them.

[0050] In some embodiments, the microporous polymer film can be formed by any of the methods described above. To contain the additive primarily in one or more surface regions of the microporous polymer film, in some embodiments, this can be achieved by forming three monolayer films (two containing the additive and one without). The two films containing the additive can then be laminated onto either side of the film without the additive. In alternative embodiments, a film containing the additive primarily in one or more surface regions can be formed by co-extruding three or more polymer blends, two of which contain the additive and the remaining polymer blends do not, to form a three-layer or multi-layer structure, wherein the outermost two layers contain the additive. The polymer blends may contain the same or different polymers.

[0051] Figures 11 to 17 These are schematic diagrams of specific co-extruded multilayer precursors, films, membranes, or separators according to some embodiments described herein. While dry co-extruded blown (bubble or annular die extrusion) and stretched products or films are preferred over cast co-extruded (groove die extrusion) and stretched products or films, similar products can be formed using groove extrusion, wet processes, particle stretching, BNBOPP, BOPP, collapsed bubble, lamination, and other processes.

[0052] In a preferred embodiment, the co-extruded precursor may have the following structures: (PP1 / PP1), (PP1 / PP2), (PP2 / PP2), (PP2 / PP1), (PP1 / PP2 / PP3), (PP3 / PP2 / PP1), (PP1 / PP2 / PP2), (PP1 / PP2 / PP1), (PP1 / PP1 / PP2), (PP2 / PP1 / PP2), (PP3 / PP3 / PP2 / PP1 / PP1), (PP3 / PP3) / PP2 / PP2 / PP1 / PP1), (PP3 / PP3 / PP3 / PP2 / PP2 / PP2 / PP1 / PP1 / PP1), etc.

[0053] PP1 can be made from homopolymer PP and additives used to modify the surface friction coefficient, including any anti-slip or anti-blocking additives such as polysiloxanes or siloxanes. PP2 can be made from the same or different PP homopolymer and PP copolymer, which can be any propylene-ethylene or ethylene-propylene random copolymer, block copolymer, or elastomer. PP3 can be made from the same or different homopolymer PP as PP1 and PP2, and may also contain additives for modifying the surface friction coefficient, which may be the same or different from the additives used in PP1, or additives for promoting coating adhesion or otherwise modifying the surface.

[0054] In other preferred embodiments, the co-extruded precursor may have the following structures: (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. PP1 may be any polypropylene blend. PP2 may be made from any PP block copolymer, including those described herein. PP3 may be made from the same or different PP-block copolymer used in PP2, and / or may also include additives that modify the surface friction coefficient, which may be the same or different from the additives used in PP1, or additives that promote coating adhesion or otherwise modify the surface.

[0055] (2) Co-extrusion or co-extrusion

[0056] Co-extrusion is not limited to this. Exemplary co-extrusion processes and co-extrusion dies can be used. In some embodiments, co-extrusion is performed using a co-extrusion die having one or more extruders feeding the die. Typically, there is one extruder for each desired layer or micron layer of the final co-extruded film. For example, if the desired co-extruded film has three micron layers, three extruders are used with the co-extrusion die. In at least one embodiment, the film of the present invention can be composed of multiple layers, micron layers, or nanolayers, wherein the final product can contain two or more layers, micron layers, and / or nanolayers. In at least certain embodiments, the micron or nanolayer technology can be produced by pre-encapsulating the feed block before entering the casting or blown film die.

[0057] In some preferred embodiments, the co-extrusion is a dry process blown (non-cast) bubble co-extrusion, and the blow-up ratio can vary between 0.5 and 2.0, preferably 0.7 to 1.8, and most preferably 0.9 to 1.2. After co-extrusion using this blow-up ratio, the film can be MD-stretched; MD-stretched, then TD-stretched; or MD-and TD-stretched simultaneously. The film can then optionally be calendered to further control the thickness or porosity.

[0058] The benefits of co-extrusion include, but are not limited to, increasing the number of layers (interfaces), which is believed (unintentionally, to be bound by any particular theory) to improve puncture strength. Moreover, without wishing to be bound by any particular theory, co-extrusion is believed to result in the observed improvement in depth density (DB). Specifically, DB improvement may be related to the uniformity or reduction in PP pore size observed when using a co-extrusion process. Furthermore, co-extrusion allows for a greater selection of materials by incorporating blends into layers or micron-layers. Co-extrusion also allows for the formation of thin bilayer, trilayer, or multilayer films (co-extruded films). For example, trilayer co-extruded films with a thickness of 8 or 10 microns or less can be formed. For higher depth densities (MD), co-extrusion allows for different pore structures (smaller for PP, larger for PE). Co-extrusion can be combined with lamination to produce desired, stronger, or unique multilayer structures. And, the minimum achievable thickness can be determined by the extrusion process. In some instances, the thinnest micron- or nanolayers are formed using co-extrusion dies.

[0059] (3) Coating

[0060] There are few restrictions on the coating and it can include any known coating used for battery separators, wherein the additives as described herein have been added to the coating. For example, the coating can be a ceramic coating comprising, consisting of, or substantially consisting of the additives herein; a coating comprising, consisting of, or substantially consisting of polycarbonate and the additives herein; or a coating comprising, consisting of, or substantially consisting of PVDF and the additives herein.

[0061] In one aspect, the coating may be the outermost coating of the partition; for example, the coating may not have any other different coatings formed thereon, or the coating may have at least one other different coating formed thereon. For example, in some embodiments, a different polymer coating may be applied in addition to or on top of a coating formed on at least one surface of the porous substrate.

[0062] In some embodiments, the coating thickness is less than about 12 μm, sometimes less than 10 μm, sometimes less than 9 μm, sometimes less than 8 μm, sometimes less than 7 μm, and sometimes less than 5 μm. In at least certain selected embodiments, the coating thickness is less than 4 μm, less than 2 μm, or less than 1 μm.

[0063] There are few restrictions on the coating method; the coating layer described herein can be applied to a porous substrate by at least one of the following methods: extrusion coating, roller coating, gravure coating, printing, doctor blade coating, air knife coating, spraying, dip coating, or curtain coating. The coating process can be carried out at room temperature or high temperature.

[0064] The coating can be any of the following: non-porous, nanoporous, microporous, mesoporous, or macroporous. The coating may have a JIS Gurley value of 700 or less, sometimes 600 or less, 500 or less, 400 or less, 300 or less, 200 or less, or 100 or less.

[0065] At least one optional coating may contain one or more additives as described herein. In some embodiments, all coated coatings contain one or more additives as described herein, and in some embodiments, some optional coated coatings contain one additive as described herein. In embodiments in which all or some coatings contain one or more additives as described herein, each coating may contain the same or different additives or mixtures of additives.

[0066] (3) Additives

[0067] There are few restrictions on the additives; they can be any additive that does not contradict the objectives described herein. In some embodiments, the additive is selected from at least one of the following: plasticizers, shrinkage-reducing agents, surfactants, and lubricants. In other embodiments, the additive is an electrolyte additive. One or more of the additives described herein can be added, and in some embodiments, a single additive has multiple functions. For example, it can be a lubricant, plasticizer, shrinkage-reducing agent, and surfactant. In some embodiments, the additive can be both a shrinkage-reducing agent and an electrolyte additive.

[0068] There are few restrictions on the amount of additive, which can be 500 to 50,000 ppm, 500 to 25,000 ppm, 500 to 15,000 ppm, or 500 to 10,000 ppm. In a preferred embodiment, the additive is added in amounts of 1,000 to 10,000 ppm, 1,000 to 9,000 ppm, 1,000 to 8,000 ppm, 1,000 to 7,000 ppm, 1,000 to 6,000 ppm, 1,000 to 5,000 ppm, 1,000 to 4,000 ppm, 1,000 to 3,000 ppm, or 1,000 to 2,000 ppm.

[0069] Crucially, the additives should not adversely affect battery chemistry or performance. The effect of the additives can be determined by plotting capacity (mAh) vs. cycle index. When comparing battery separators with and without additives, the graphs should not show significant differences. (4) Additives selected from lubricants, plasticizers, shrinkage reducers and / or surfactants.

[0070] There are few limitations on the lubricating media or lubricants described herein. As those skilled in the art will understand, lubricants are compounds used to reduce friction between various surfaces, including: polymers; metals; organic materials; and inorganic materials. Specific examples of the lubricating media or lubricants described herein are compounds containing silanoxy functional groups (including siloxanes and polysiloxanes) and fatty acid salts (including metal stearates).

[0071] Compounds containing two or more, three or more, four or more, five or more, six or more, seven or more, eight or more, nine or more, or ten or more siloxanes can be used as the lubricants described herein. As understood by those skilled in the art, siloxanes are a class of molecules with alternating silicon (Si) and oxygen (O) atoms as the backbone, each silicon atom potentially having a linked hydrogen (H) or a saturated or unsaturated organic group, such as -CH3 or C2H5. Polysiloxanes are polymerized siloxanes, typically having a high molecular weight. In some preferred embodiments described herein, the polysiloxane can be a high molecular weight, or in some cases even more preferably an ultra-high molecular weight polysiloxane. In some embodiments, the weight-average molecular weight of high and ultra-high molecular weight polysiloxanes can be between 500,000 and 1,000,000.

[0072] There are few limitations on the fatty acid salts described herein, and they can be any fatty acid salt that functions as a lubricant. The fatty acids in the fatty acid salts can be fatty acids having 12 to 22 carbon atoms. For example, the metallic fatty acids can be selected from: lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, palmitoleic acid, behenic acid, erucic acid, and arachidic acid. There are few limitations on the metal, but in preferred embodiments, it is an alkali metal or alkaline earth metal, such as Li, Be, Na, Mg, K, Ca, Rb, Sr, Cs, Ba, Fr, and Ra. In some preferred embodiments, the metal is Li, Be, Na, Mg, K, or Ca.

[0073] In some preferred embodiments, the fatty acid salt is lithium stearate, sodium stearate, lithium oleate, sodium oleate, sodium palmitate, lithium palmitate, potassium stearate, or potassium oleate.

[0074] In some preferred embodiments described herein, the lubricants (including fatty acid salts) described herein have melting points of 200°C or higher, 210°C or higher, 220°C or higher, 230°C or higher, or 240°C or higher. Fatty acid salts such as lithium stearate (melting point 220°C), sodium stearate (melting point 245 to 255°C), or potassium stearate (melting point 240°C) have such melting points. Fatty acid salts such as calcium stearate (melting point 155°C) do not. The inventors of this application have found that, from a processing perspective, calcium stearate is less desirable than other fatty acid metal salts (e.g., metal stearates) with higher melting points. In particular, it has been found that calcium stearate cannot be added in amounts higher than 800 ppm without the so-called "snowfall effect," in which wax separates and spreads throughout the body during hot extrusion. Not wishing to be bound by any particular theory, it is believed that using fatty acid metal salts with melting points higher than the hot extrusion temperature can solve this "snowfall" problem. Fatty acid salts with melting points higher than calcium stearate, particularly those with melting points above 200°C, can be added in amounts exceeding 1% or 1,000 ppm without “snowing down.” Amounts of 1% or higher have been found to be important for achieving desired properties (e.g., improved wettability and improved needle removal), particularly for thinner septa. In some embodiments, amounts particularly preferred for this purpose are 1,000 to 10,000 ppm, 1,000 to 9,000 ppm, 1,000 to 8,000 ppm, 1,000 to 7,000 ppm, 1,000 to 6,000 ppm, 1,000 to 5,000 ppm, 1,000 to 4,000 ppm, 1,000 to 3,000 ppm, or 1,000 to 2,000 ppm.

[0075] In some other preferred embodiments, the solubility of the fatty acid salt may be equal to or greater than that of lithium stearate in water; that is, the metallic fatty acid has the same or higher solubility as lithium stearate in water. This makes it easier to incorporate the additive into the coating slurry, including ceramic coating slurries.

[0076] There are few limitations on the plasticizing media or plasticizers described herein. As those skilled in the art will understand, a plasticizer is a compound that can be added to a polymer to make it easier to process and / or handle. For example, plasticizers reduce interactions between polymer segments, lower Tg, melt viscosity, and / or reduce the elastic modulus. In some embodiments, the selected plasticizer is a non-volatile material and has good compatibility with one or more polymers to be processed. In some preferred embodiments herein, the plasticizer is lithium stearate.

[0077] There are few limitations on the nucleating media or nucleating agents described herein, and they can be any nucleating media or nucleating agents that do not contradict the objectives described herein. As those skilled in the art will understand, nucleating media or nucleating agents are inorganic materials added to polymers to increase crystallinity and shorten cycle time. They accelerate the transition from molten material to solid material. Changing the crystallinity of a polymer alters other properties of the polymer. For example, nucleating agents can increase the porosity of microporous polymer films containing them, which is accompanied by a decrease in the Gurley value of the film. In some preferred embodiments herein, the nucleating agent is lithium stearate.

[0078] There are few limitations on the shrinkage reducing agent described herein, and it can be any shrinkage reducing agent that does not contradict the objectives described herein. A shrinkage reducing agent is a compound that, when added to the microporous polymer film described herein, reduces the shrinkage of the film in any direction, particularly the processing direction (MD) and / or transverse direction (TD, which is perpendicular to the MD direction). In some preferred embodiments herein, the shrinkage reducing agent is lithium stearate.

[0079] There are few limitations on the surfactants or surfactant media described herein, and they can be any surfactant that does not contradict the purposes described herein. As those skilled in the art will understand, surfactants or surfactant media are organic or inorganic compounds soluble in water and / or organic solvents. Surfactant molecules are amphiphilic, meaning they contain a hydrophilic or hydrophilic group (“head” portion) and a hydrophobic or hydrorepellent group (“tail” portion). This amphiphilic nature allows surfactants to interact with polar (e.g., water) and nonpolar molecules (e.g., oils). Surfactants include, for example, synthetic, anionic, amphoteric, zwitterionic, cationic, and nonionic surfactants. In some preferred embodiments herein, the surfactant is at least one fatty acid salt described herein, including lithium stearate.

[0080] In some embodiments, the additives are compounds of surfactants, shrinkage reducers, nucleating agents, plasticizers, and lubricants. An example of such an additive is lithium stearate.

[0081] (5) Electrolyte additives

[0082] There are few limitations on the electrolyte additives described herein, as long as the electrolyte aligns with the objectives described herein. The electrolyte additive can be any additive typically added by battery manufacturers, particularly lithium-ion battery manufacturers, to improve battery performance. The electrolyte additive must also be compatible with the polymer used for the polymer microporous film (e.g., miscible) or with the coating slurry. The miscibility of the additive can also be aided or improved by coating or partially coating the additive. For example, exemplary electrolyte additives are disclosed in *A Review of Additives for Lithium-ion Battery Electrolytes* (J. of PowerSources, Vol. 162, No. 2, 2006, pp. 1379-1394), the entire contents of which are incorporated herein by reference. In some preferred embodiments, the electrolyte additive is at least one selected from SEI improvers, cathodic protectants, flame retardants, LiPF6 salt stabilizers, overcharge protectants, aluminum corrosion inhibitors, lithium depositors or improvers or solvation enhancers, aluminum corrosion inhibitors, wetting agents, and viscosity improvers. In some embodiments, the additive may have more than one property; for example, it may be a wetting agent and a viscosity improver.

[0083] Exemplary SEI modifiers include VEC (vinyl ethylene carbonate), VC (vinyl carbonate), FEC (fluoroethylene carbonate), and LiBOB (lithium bis(oxalate)borate). Exemplary cathodic protectants include N,N'-dicyclohexylcarbodiimide, N,N-diethylaminotrimethylsilane, and LiBOB. Exemplary flame retardant additives include TTFP (tris(2,2,2-trifluoroethyl) phosphate), fluorinated propylene carbonate, and MFE (methyl nonafluoroboron ether). Exemplary LiPF6 salt stabilizers include LiF, TTFP (tris(2,2,2-trifluoroethyl) phosphite), 1-methyl-2-pyrrolidone, fluorinated carbamate, and hexamethylphosphoramide. Exemplary overcharge protectants include xylene, cyclohexylbenzene, biphenyl, 2,2-diphenylpropane, and phenyl-tert-butyl carbonate. Exemplary lithium deposition modifiers include AlI3, SnI2, hexadecyltrimethylammonium chloride, perfluoropolyethers, and tetraalkylammonium chloride having long alkyl chains. Exemplary ionic solvation enhancers include 12-crown ether-4 and TPFPB (tris(pentafluorophenyl)). Exemplary aluminum corrosion inhibitors include LiBOB, LiODFB, and borates, for example. Exemplary wetting agents and viscosity diluents include cyclohexane and P2O5.

[0084] In some preferred embodiments, the electrolyte additive is air-stable or oxidation-resistant. Battery separators containing the electrolyte additives disclosed herein can have a shelf life of several weeks to several months, for example, one week to 11 months. This means that, for example, in one week, two weeks, three weeks, four weeks, two months, three months, four months, five months, six months, seven months, eight months, nine months, ten months, or eleven months, when the battery separator is used in a lithium-ion battery, the separator will retain its ability to release the electrolyte additive into the electrolyte of the lithium-ion battery. For example, it will retain 70%, 80%, 90%, 95%, or 100% of its initial ability to release the electrolyte into the electrolyte of the lithium-ion battery. Once the battery separator is incorporated into the battery, it is no longer exposed to air and therefore will no longer be affected by any significant degree of oxidation. While coatings can be added to the separator to prevent oxidation and extend the shelf life of the battery separator, its shelf life is measured without the addition of coatings that prevent or slow down oxidation.

[0085] (6) Complex, vehicle or device

[0086] The composite comprises any separator as described above and one or more electrodes, such as an anode, cathode, or anode and cathode, configured to be in direct contact therewith. There are few restrictions on the type of electrodes. For example, the electrodes can be those suitable for use in lithium-ion secondary batteries.

[0087] A suitable anode may have a specific capacity greater than or equal to 372 mAh / g, preferably ≥700 mAh / g, and most preferably ≥1000 mAh / g. The anode is composed of lithium metal foil or lithium alloy foil (e.g., lithium-aluminum alloy) or a mixture of lithium metal and / or lithium alloy, as well as materials such as carbon (e.g., coke, graphite), nickel, and copper. The anode is not made solely of lithium-containing intercalation compounds or lithium-containing insertion compounds.

[0088] A suitable cathode can be any cathode compatible with the anode and may include intercalating compounds, insertion compounds, or electrochemically active polymers. Suitable intercalating materials include, for example, MoS2, FeS2, MnO2, TiS2, NbSe3, LiCoO2, LiNiO2, LiMn2O4, and V6O. 13 V₂O₅ and CuCl₂. Suitable polymers include, for example, polyacetylene, polypyrrole, polyaniline and polythiophene.

[0089] A suitable electrolyte can be any electrolyte suitable for lithium-ion batteries. For example, in some embodiments, the electrolyte can be a lithium salt in a liquid solvent (e.g., SO2 or SOCl2).

[0090] Any of the partitions described above can be incorporated into any vehicle (e.g., an electric vehicle) or device (e.g., a cell phone or laptop) that is fully or partially powered by a battery.

[0091] (7) Method

[0092] The method of forming the battery separator described herein comprises, or substantially comprises, at least one of the following steps: (1) forming a microporous polymer film from a polymer mixture comprising a polymer and any additives or electrolyte additives disclosed herein; and (2) coating the microporous polymer film with a coating mixture comprising any additives or electrolyte additives. In some embodiments, forming the microporous polymer film comprises extruding or co-extruding a polymer mixture, i.e., extruding a polymer mixture with one or more other polymer mixtures, with or without any additives or electrolyte additives disclosed herein. In some embodiments, forming the microporous film further comprises stretching the extruded polymer to form pores. In some embodiments, the microporous film is a single-layer, double-layer, triple-layer, or multilayer film. A single layer can be formed by extrusion, a double layer by co-extrusion, a triple layer by co-extrusion, or a multilayer by co-extrusion. A double-layer film can be formed by extruding two single layers and laminating them together. In some embodiments, a triple layer can be formed by extruding three single layers and laminating them together. A multilayer can be formed by extruding two or more single layers and laminating them together. A multilayer can be formed by co-extruding three separate co-extruded triple layers and laminating them together. Multilayers can be formed by co-extruding three separate bilayers and laminating them. These are exemplary methods for forming the microporous films described herein.

[0093] In some embodiments, the battery separator described herein can be formed, at least by coating a microporous polymer film with a coating mixture containing any of the additives or electrolyte additives described herein. There are few limitations on the coating mixture; it can be a ceramic coating mixture. The coating mixture can be coated on one or more sides of the microporous film.

[0094] There are few restrictions on the coating method; the coating described herein can be applied to a porous substrate by at least one of the following methods: extrusion coating, roller coating, gravure coating, printing, doctor blade coating, air knife coating, spraying, dip coating, or curtain coating. The coating process can be carried out at room temperature or high temperature.

[0095] Various embodiments of the invention have been described to achieve its various objectives. It should be understood that these embodiments are merely illustrative of the principles of the invention. Many modifications and adjustments will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

[0096] Example

[0097] Depending on at least selected embodiments, aspects, or purposes, additives may be provided and added to microporous membranes (films) or separator membranes for secondary batteries. In some embodiments, the membrane (film) may contain additives that improve battery (e.g., lithium-ion battery) performance. In other selected embodiments, the membrane may contain additives, such as polysiloxanes or lithium stearate, that improve battery manufacturing-related properties, such as ease of needle removal.

[0098] Polysiloxane Examples

[0099] It is prepared by forming two single-extruded PP layers and one single-extruded PE layer. Figure 1 TDX143 is used in this process. The single-extruded PP layer is formed by extruding a mixture containing polysiloxane. The three layers are laminated together to form a sandwich structure with the single-extruded PE layer in the middle. Stretching is also performed to make the resulting film microporous. The amount of polysiloxane is 3,000 ppm or 3%. Figure 1 The results showed that the needle removal force of TDX143 was reduced by adding polysiloxane. Figure 1 TDX144, also a three-layer PP-PE-PP film, is prepared in the same manner as TDX143 (except without the addition of polysiloxane), exhibiting higher needle removal force at winding tensions of 200g and 350g. Significant lubrication is achieved using polysiloxane. Additionally, when... Figure 2 When up to 3% or 30,000 ppm of polysiloxane is added to the membrane shown, the puncture strength is improved.

[0100] As mentioned above, it is crucial that the additives do not adversely affect the battery's chemistry or performance. Figure 3 This indicates that adding polysiloxane to the porous membrane separator will not affect the battery system that passes the cyclic voltammetry test. Figure 4 Further battery cycle tests show that the capacity after 300 cycles is very similar for batteries containing 0% and 4.5% polysiloxane.

[0101] It is prepared by forming two single-extruded PP layers and one single-extruded PE layer. Figure 5 SX112 is used in this process. The single-extruded PP layer is formed by extruding a mixture containing polysiloxane. The three layers are then laminated together to form a sandwich structure with the single-extruded PE layer in the middle. Stretching is also performed to make the resulting film microporous. The amount of polysiloxane is 3,000 ppm or 3%. Figure 5SX113 is also a three-layer PP-PE-PP film prepared in the same way as SX112, the difference being that no polysiloxane is added. Figure 5 The results show that, due to the addition of polysiloxane to the PP layer, the PP pore size of SX112 is larger than that of SX113, while the PE pore size of the two films is the same.

[0102] The testing methods are described in the “Testing Methods” section below.

[0103] Lithium stearate examples

[0104] In other embodiments, the additive can be a metal stearate, such as lithium stearate. One function of lithium stearate is to reduce needle removal force. It is a better lubricant than, for example, calcium stearate, because it has a higher melting point and less tendency to “bloom” or “snow” during extrusion. Due to its reduced tendency to “bloom” or “snow,” a higher loading can be used, for example, up to 5%. Figure 6 The results showed that the needle removal force of a 24 μm thick monolayer polypropylene septum decreased after the addition of 2% (20,000 ppm) or 5% (50,000 ppm) of LiSt.

[0105] Lithium stearate acts as a processing aid and plasticizer. It reduces the viscosity of the polymer, thus requiring much lower processing temperatures. Data in Table 1 indicate that, depending on the resin, the extruder and die temperatures may need to be reduced by 10°C to 30°C after adding 5% (50,000 ppm) of lithium stearate. In Table 1, resin 1 and resin 2 are polypropylene resins.

[0106] Table 1

[0107]

[0108] The use of lithium stearate as an additive in polypropylene can also improve the wettability of the membrane electrolyte. Table 2 shows the average contact angle of polypropylene membranes using propylene carbonate-based electrolytes (which are the most difficult electrolyte solvents to wet) with no additive and with 2% (20,000 ppm) and 5% (50,000 ppm) lithium stearate. A decrease in contact angle from 91.5 degrees to 81.4 degrees was observed when using 5% lithium stearate.

[0109] Table 2

[0110]

[0111] In other selected embodiments, the addition of lithium stearate to the porous membrane can effectively increase the pore size and porosity. Figure 7This is a pore distribution diagram of a PP membrane measured using an Aquapore porosimeter via the water intrusion method. An increase of 25% in pore size was observed with the addition of 5% LiSt. Without wishing to be bound by any particular theory, this phenomenon is believed to be due to the nucleation effect of lithium stearate, i.e., lithium stearate acting as a nucleating medium or nucleating agent.

[0112] Figure 8 The DSC capping layer also clearly illustrates the nucleation effect of lithium stearate; that is, when 5% lithium stearate is added, the peak crystallization temperature of Prime Polymer polypropylene increases from 165.63°C to 168.73°C. Due to the higher peak crystallization temperature, the polymer can generate more crystalline precursors to create more pores in the porous membrane. Table 3 shows an overall comparison of 24 μm monolayer polypropylene membranes containing 0%, 2%, and 5% lithium stearate. Advantages include a lower Gurley value and reduced shrinkage.

[0113] Table 3

[0114]

[0115] Figure 9 The lifetime of membranes with 2 or 5% lithium stearate is shown compared to the control. The curves indicate that a loading of less than 5% is optimal to avoid potential capacity decay.

[0116] Main reference Figures 11 to 17 In addition to other multi-layered implementations, the following are further embodiments 10 to 23:

[0117] Example 10:

[0118] Each PP and PE layer in the three-layer structure consists of multiple 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 of 0.90 g / cm³. 3 The melt flow rate (MFR) ranges from 0.5 MFR to 2 MFR. All PE layers are made from a blend of 95% high-density polyethylene (HDPE) and 5% mLLDPE. The HDPE has a melt flow index of 0.25-0.5 g / 10 min at 2.16 kg and 190°C, and a density range of 0.955-0.966 g / cm³. 3 .

[0119] Example 11:

[0120] (PP1 / PP2 / PP3) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is a blend or block copolymer that is the same as or different from PP1 and PP2.

[0121] Example 12:

[0122] (PP1 / PP1) or (PP2 / PP2) or (PP1 / PP2) - PP1 is a polypropylene blend, and PP2 is a PP block copolymer.

[0123] Example 13:

[0124] (PP1 / PP1 / PP1) or (PP2 / PP2 / PP2)-PP1 is a polypropylene blend, and PP2 is a PP block copolymer.

[0125] Example 14:

[0126] (PP1 / PP2 / PP3) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is a PP block copolymer that may be the same or different.

[0127] Example 15:

[0128] (PP3 / PP2 / PP1) / (PP3 / PP2 / PP1)-PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is a PP block copolymer of the same or different types.

[0129] Example 16:

[0130] (PP1 / PP2 / PP3) / (PP3 / PP2 / PP1) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is a PP block copolymer that is the same or different.

[0131] Example 17:

[0132] (PP1 / PP2) / (PP3 / PP1) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is a PP block copolymer that is the same as or different from the PP.

[0133] Example 18:

[0134] (PP1 / PP2 / PP3 / PP1) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 is a PP block copolymer that is the same as or different from other PP blocks.

[0135] Example 19:

[0136] (PP1 / PP2 / PP3) - PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PP3 includes an adhesion promoter.

[0137] Example 20:

[0138] (PO3 / PP2 / PP1)-PP1 is a polypropylene blend, PP2 is a PP block copolymer, and PO3 is a polyolefin blend (such as PP+PE).

[0139] Example 21:

[0140] (PP1 / PP2 / PP3) - PP1 is a homopolymer PP + additives used to modify the coefficient of friction as described herein, which may include any lubricating or adhesive additives such as siloxanes. PP2 is a homopolymer PP that may be the same as or different from the homopolymer PP 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 + additives, the homopolymer being the same as or different from the homopolymer PP in PP1 and PP2, and the additives used to modify the coefficient of surface friction (COF) being the same as or different from the additives used in PP1.

[0141] Example 22:

[0142] (PP3 / PP2 / PP1) - PP1 is homopolymer PP + additives used to modify the coefficient of friction (COF) as described herein, which may include any lubricating or adhesive additives such as siloxanes. PP2 is homopolymer PP + copolymer PP, the homopolymer PP being the same as or different from the homopolymer PP used in PP1 and PP3, and the copolymer PP can be any propylene-ethylene or ethylene-propylene random copolymer, block copolymer, or elastomer. PP3 is homopolymer PP + additives, the homopolymer PP being the same as or different from the homopolymer PP in PP1 and PP2, and the additives used to modify the surface coefficient of friction being the same as or different from the additives used in PP1.

[0143] Example 23:

[0144] (PP3 / PP2 / PP1) or (PP1 / PP2 / PP3)-PP1 is a homopolymer PP plus an additive used to modify the coefficient of friction (COF) as described herein, which may include any lubricating or adhesive additives such as siloxanes. PP2 is a homopolymer PP plus a copolymer PP, the homopolymer PP being the same as or different from the homopolymer PP used in PP1 and PP3, and the copolymer PP can be any propylene-ethylene or ethylene-propylene random copolymer, block copolymer, or elastomer. PP3 is a homopolymer PP plus a copolymer PP, the homopolymer PP being the same as or different from the homopolymer PP used in PP1 and PP2, and the copolymer PP can be any propylene-ethylene or ethylene-propylene random copolymer, block copolymer, or elastomer.

[0145] The composition of the product layers can be compared as follows:

[0146] Comparative Example 1 – Typical single-layer PP (e.g., Celgard 2500)

[0147] Comparative Example 2 – Typical Three-Layer PP / PE / PP

[0148] Comparative Example 3 – Typical single-layer PP or typical three-layer (PP / PE / PP) ceramic-coated version

[0149] Test methods

[0150] Gurley value

[0151] In this article, the Gurley value is defined as the Japanese Industrial Standard (JIS Gurley value), and is measured using an OHKEN permeability tester. The JIS Gurley value is defined in seconds as the time, in seconds, required for 100 cc of air to pass through a one square inch membrane under a constant pressure of 4.9 inches of water.

[0152] thickness

[0153] Thickness was measured in micrometers (μm) using an Emveco Microgage 210-A micrometer thickness tester and test procedure ASTM D374.

[0154] Tensile strength

[0155] The tensile strength in the machining direction (MD) and transverse direction (TD) was measured using an Instron Model 4201 according to ASTM-882 specifications.

[0156] MD (Mean Elongation at Break) is the percentage of elongation of a test sample along the processing direction, measured at the maximum tensile strength required for sample fracture.

[0157] TD breaking tensile strength % is the percentage of elongation of a test sample in the transverse direction, measured at the maximum tensile strength required for the sample to break.

[0158] Puncture strength

[0159] Puncture strength was measured using the Instron Model 4442 based on ASTM D3763. Measurements were performed across the width of the microporous membrane, and puncture strength was defined as the force required to puncture the test sample.

[0160] Heat shrinkage

[0161] Shrinkage is measured by placing the test sample between two sheets of paper, clamping them together to hold the sample in place, and suspending it in an oven. For the "105°C for 1 hour" test, the sample is placed in an oven at 105°C for 1 hour. After maintaining the specified heating time in the oven, each sample is removed and adhered to a flat, opposite surface with double-sided tape to flatten and smooth the sample for accurate length and width measurements. Shrinkage is measured in the machining direction (MD) and transverse direction (TD) and expressed as MD shrinkage % and TD shrinkage % respectively.

[0162] aperture

[0163] Aperture was measured using an Aquapore instrument available from Porous Materials, Inc. (PMI). Aperture is expressed in μm.

[0164] Porosity

[0165] The porosity of microporous film samples was measured using ASTM method D-2873 and defined as the percentage of voids in the microporous membrane measured in both the processing direction (MD) and transverse direction (TD).

[0166] Dielectric breakdown (DB)

[0167] A voltage was applied to the separator film until dielectric breakdown of the sample was observed. A robust separator exhibited a high dB value. Inhomogeneities in the separator film may cause a decrease in the dB value.

[0168] Differential capacity analysis

[0169] Differential capacity analysis was performed to investigate the electrochemical stability of the additive material in a typical lithium-ion battery electrolyte (1M LiPF6 in a 3:7 EC:EMC). Differential capacity analysis is commonly used to study the electrochemical properties of analytes in solution. The scan rate was 15 mA / g.

[0170] Contact angle

[0171] The contact angle of propylene carbonate was measured using a KRUSS DSA100 contact angle analyzer. Measurements were taken within 3 seconds of dispensing the droplets. The average contact angle of 10 droplets was reported as the membrane contact angle.

[0172] Needle removal force

[0173] Split strips 6 inches long and 45 mm wide are wound into cores with tensions of 50 g, 200 g, and 350 g. The needles are 4 mm in diameter and 61 mm in length. After winding, the maximum force required to pull one or both needles out of the core is measured and reported as the needle removal force.

[0174] Shear viscosity

[0175] Viscosity was measured using a TA HR-2 Discovery Hybrid rheometer with parallel plates and a 1 mm gap.

[0176] electrostatic charge

[0177] After the separator was dried for at least 24 hours, all measurements were collected in a dry laboratory. A SIMCO ion electrostatic field meter was used. The measurement distance was 25 mm from the separator surface.

[0178] resistance

[0179] Resistance can be measured in non-battery electrolytes (e.g., solutions of KCl and deionized water) using an Agilent LCR meter or an Instek LCR meter. Separator samples are prepared by cutting each different separator into four identical samples. Resistance measurements are performed on separators with 1, 2, 3, and 4 layers.

[0180] DSC

[0181] DSC analysis was performed to determine the melting temperature (Tm) and the onset of crystallization. A Netzsch DSC analyzer with a sealed aluminum sample holder featuring a porous cap was used. Nitrogen was used as the carrier gas at a flow rate of 40 ml / min to prevent sample oxidation. The mass of the analyzed samples ranged from 5 to 6 mg. To determine Tm and the onset of crystallization, the samples were first heat-treated to eliminate thermal history. Next, another heating and cooling cycle was performed at a rate of 10 °C / min, starting at 25 °C and progressing to 300 °C. Data acquisition and processing were performed using Proteus analysis software. The PE and PP layers were evaluated separately.

[0182] MD stretching ratio (%)

[0183] MD (Mean Elongation at Break) is the percentage of elongation of a test sample along the machining direction, measured at the maximum tensile strength required for sample breakage.

[0184] TD stretching ratio (%)

[0185] TD breaking tensile strength % is the percentage of elongation of the test sample along the transverse direction, measured at the maximum tensile strength required for sample breakage.

[0186] Shutdown temperature (°C)

[0187] With a resistance reading of 100W×cm 2 Record the initial shut-off temperature in °C.

[0188] Closing speed (ohm-cm) 2 )

[0189] The thin film of the example was sandwiched between two nickel disks and wetted with PC solvent. The wet partition stack was then subjected to a temperature increase of 60°C / min. During the test, the resistance between the two nickel disks was monitored with a multimeter. For this test, closure was defined as a resistance of 100 W × cm. 2 Increase by two orders of magnitude to 10,000 W × cm 2 The result is normalized by the time required for the resistance to rise. The closing speed is expressed in W × cm. 2 The unit is / sec.

[0190] McMillan

[0191] The McMillan number is calculated using the electrical impedance (ER) measurement results. The calculation is as follows: McMillan number = ((electrical impedance (Ω-cm)) / (electrical impedance (Ω-cm)) 2 ) / Separator thickness (cm) / Electrolyte resistivity (ohm-cm).

[0192] Cycle life

[0193] All cycles were performed in constant current (CC) mode.

[0194] Calculated curvature

[0195] The curvature is calculated using the following formula (1):

[0196] Nm = T 2 / P (1)

[0197] Where Nm is the McMillan number, T is the curvature, and P is the porosity. Without being bound by any particular theory, it is believed that battery separators with higher curvature will be safer. This is thought to be because the growth of dendrites between electrodes will be more difficult, as they will have to follow a more tortuous path from the anode to the cathode.

[0198] According to at least selected embodiments, aspects, or purposes, this application or invention is committed to additives for improving battery performance, improved films containing additives, improved battery separators, and / or improved batteries, and / or improved or related methods of manufacturing and / or using them. According to at least specific embodiments, this application or invention is committed to additive-containing films, separator films, and / or battery separators, and / or methods of preparing and / or using such films, separator films, and / or battery separators. According to at least particular embodiments, this application or invention is committed to adding additives to microporous films or separators used in secondary lithium batteries (e.g., secondary lithium-ion batteries), improved battery separators, and / or related methods. In some embodiments, the film may contain additives that improve performance in battery chemistry (e.g., lithium-ion batteries). In other selected embodiments, the film may contain additives that improve needle removal performance, such as siloxanes or lithium stearate. In other specific embodiments, the invention may also relate to methods of preparing such films or separator films and methods of using such films or separator films, for example, as lithium battery separators. According to at least selected embodiments, this application or invention is directed to new or improved porous membranes, separator membranes, separators, dry-process separators, composites, electrochemical devices, and batteries, as well as methods for manufacturing such membranes, separators, composites, devices, and / or batteries. According to at least specific selected embodiments, the invention is directed to new or improved separators containing additives or elastomers. Improved membranes may preferably exhibit improved shut-off, improved strength, improved dielectric breakdown strength, and / or reduced cracking tendency. According to at least specific selected embodiments, this application or invention is directed to battery separators having a microporous polymer film or membrane and an optional coating layer on at least one side of the microporous polymer film, wherein at least one of the microporous polymer film and the optional coating contains an additive. Additives may be selected from lubricants, plasticizers, nucleating agents, shrinkage reducers, surfactants, SEI modifiers, cathodic protection agents, flame retardant additives, LiPF6 salt stabilizers, overcharge protectors, aluminum corrosion inhibitors, lithium deposition agents or modifiers or solvation enhancers, aluminum corrosion inhibitors, wetting agents, viscosity modifiers, friction reducers, COF reducers, needle removal force weakeners, copolymers, block copolymers, and / or combinations thereof. Furthermore, this document describes batteries (including primary or secondary lithium batteries) comprising one or more of the described films, membranes, coatings, and / or separators. Methods for manufacturing the films, membranes, coatings, and / or battery separators are also described.According to at least a particular embodiment, this application or invention is committed to an improved or new battery separator having at least one of the following: enhanced puncture strength, reduced needle removal force, improved electrolyte wettability and increased pore size, and a microporous polymer film having an optional coating layer on at least one side thereof; a battery separator having at least one of an optional coating and a microporous polymer film, comprising an additive selected from lubricants, surfactants, nucleating agents, shrinkage reducers and / or plasticizers therein and / or on it; the microporous polymer film having an additive that is primarily present in at least one surface region of the film, or present throughout the film, in a single surface region of the film, in a first surface region of the film and in a second surface region of the film opposite to the first surface region; a coating applied to the surface of the microporous polymer film, the coating being applied only to one surface of the microporous polymer film, applied to a first side of the microporous polymer film, while other coatings may be applied to a second side of the microporous polymer film opposite to the first side, and / or combinations thereof. According to at least a preferred embodiment, the microporous polymer film or membrane is a microporous polyolefin film, such as a dry-stretched process film, including single-layer, double-layer, or multi-layer dry-process films. Furthermore, according to at least a preferred embodiment, one, two, three, four, or all five different types of additives may be added, or a single additive may be added to the film, coating, or separator, acting as one, two, three, four, or all five different types of additives; for example, an additive that is both a lubricant and a surfactant may be added therein or on it.

[0199] The invention may be implemented in other forms without departing from its spirit and essential attributes; therefore, when indicating the scope of the invention, reference should be made to the appended claims rather than the foregoing description. Disclosed are components that can be used to implement the disclosed methods and systems. These and other components are disclosed herein, and it should be understood that, for all methods and systems, while specific references to each individual and collective combination and permutation of these components may not be explicitly disclosed, each is particularly considered and described herein. This applies to all aspects of this application, including but not limited to the steps in the disclosed methods. Therefore, if various additional steps are available, it should be understood that each of these additional steps can be performed using any particular implementation or combination of implementations of the disclosed methods.

[0200] The foregoing written description of the structures and methods is given for illustrative purposes only. The embodiments are provided to disclose exemplary implementations, including best practices, and to enable those skilled in the art to practice the invention (including making and using any apparatus or system and performing any combination of methods). These embodiments are not intended to be exhaustive or to limit the invention to the precise steps and / or forms disclosed; many modifications and variations are possible in accordance with the foregoing teachings. The features described herein can be combined in any combination. The steps of the methods described herein can be performed in any physically possible order. The patentable scope of the invention is defined by the appended claims and may include other embodiments that would occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements identical to the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

[0201] The composites and methods described in the appended claims are not limited to the specific composites and methods described herein. Various modifications to the composites and methods other than those shown and described herein are intended to fall within the scope of the appended claims. Furthermore, although only specific and representative composites and method steps disclosed herein are specifically described, other combinations of composites and method steps are also intended to fall within the scope of the appended claims, even if not specifically stated. Therefore, combinations of steps, elements, components, or components may be referred to explicitly or less explicitly herein; however, other combinations of steps, elements, components, or components are included even if not explicitly stated.

[0202] When used in the specification and appended claims, the singular forms “a,” “an,” and “the” include plural indications unless the context clearly indicates otherwise. A range herein may be expressed as from “about” or “approximately” a particular value, and / or to “about” or “approximately” another particular value. When such a range is expressed, an alternative embodiment includes from one particular value and / or to another particular value. Similarly, when a numerical value is expressed as an approximation using the antecedent “about,” it should be understood that the particular value forms an alternative embodiment. It should further be understood that each endpoint of a range is significant relative to and independent of the other endpoint. “Optional” or “optionally” means that an event or condition subsequently described may or may not occur, and the description includes both scenarios where the event or condition occurs and scenarios where the event or condition does not occur.

[0203] Throughout this specification and claims, the word “comprising” and variations thereof, such as “comprising in participle form” and “comprising in singular form”, means “including, but not limited to” and is not intended to exclude, for example, other additives, components, integers, or steps. The terms “consistently of” and “comprises of” are used in place of “comprising” and “including” to provide more specific embodiments of the invention, which are also disclosed therein. “Exemplary” or “for example” means “an example” and is not intended to convey that it is a preferred or ideal embodiment. Similarly, “such as” is not used in a limiting sense but for illustrative or exemplary purposes.

[0204] Unless otherwise stated, all figures used in the specification and claims to indicate geometry, dimensions, etc., are not intended to limit the application of the doctrine of equivalence to the scope of the claims, and should at least be understood to be interpreted in accordance with significant figures and conventional rounding methods.

[0205] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed invention pertains. Publications cited herein, and the material they reference, are expressly incorporated herein by reference.

[0206] Furthermore, the inventions disclosed illustratively herein may be practiced in the absence of any elements not specifically disclosed herein.

Claims

1. A battery separator, comprising: Microporous polymer films; and A coating on at least one side of a microporous polymer film, wherein the microporous polymer film comprises an additive, wherein... The additive contains ultra-high molecular weight polysiloxane and fatty acid salts with melting points above 200°C; the concentration of the fatty acid salts is at least 1%.

2. The battery separator as described in claim 1, wherein, The fatty acid salt is lithium stearate, sodium stearate, lithium oleate, sodium oleate, sodium palmitate, lithium palmitate, potassium stearate, or potassium oleate.

3. The battery separator as described in claim 1, wherein, Microporous polymer films contain additives that act as lubricants, plasticizers, nucleating agents, shrinkage reducers, and / or auxiliary surfactants.

4. The battery separator as described in claim 1, wherein, Microporous polymer films are nonwovens.

5. The battery separator as described in claim 4, wherein, The nonwoven fabric is a dry-process single-layer film, a dry-process double-layer film, a dry-process multilayer film, or a microporous polymer film containing polyolefins.

6. The battery separator as described in claim 1, wherein, The additives are mainly present in one or more surface regions of the microporous polymer film.

7. The battery separator as described in claim 6, wherein, The fatty acid salt is selected from lithium stearate, sodium stearate, and potassium stearate.

8. The battery separator as described in claim 3, wherein, The additives further include plasticizers.

9. The battery separator as described in claim 3, wherein, The additives further include nucleating agents.

10. The battery separator as claimed in claim 3, wherein, The additives further include auxiliary surfactants.

11. The battery separator as claimed in claim 3, wherein, The additives further include shrinkage-reducing agents.

12. A lithium battery comprising the battery separator as claimed in claim 1.

13. A dry-process membrane, comprising: Microporous polymer films; and A coating is applied to at least one side of the microporous polymer film, wherein, The microporous polymer film contains additives selected from lubricants, plasticizers, nucleating agents, shrinkage reducers, and auxiliary surfactants. The additives contain ultra-high molecular weight polysiloxanes and fatty acid salts with melting points above 200°C; the concentration of the fatty acid salts is at least 1%.

14. The membrane of claim 13, wherein, The coating contains additives.

15. The membrane of claim 13, wherein, The microporous polymer film contains additives; these additives are primarily present in one or more surface regions of the microporous film.

16. The membrane of claim 13, wherein, Microporous polymer films are nonwovens.

17. The membrane of claim 16, wherein, The nonwoven fabric is a dry-process single-layer film, a dry-process double-layer film, a dry-process multilayer film, or a microporous polymer film containing polyolefins.

18. The membrane of claim 13, wherein, The fatty acid salt is selected from lithium stearate, sodium stearate, and potassium stearate.

19. The membrane of claim 13, wherein, The additive is a plasticizer.

20. The membrane of claim 13, wherein, The additive is a nucleating agent.

21. The membrane of claim 13, wherein, Additives are auxiliary surfactants.

22. The membrane of claim 13, wherein, The additive is a shrinkage reducer.

23. A battery separator, comprising: Microporous polymer films; and A coating on at least one side of a microporous polymer film, wherein, The microporous polymer film comprises a polysiloxane with a weight-average molecular weight between 500,000 and 1,000,000 and a fatty acid salt with a melting point above 200°C; the fatty acid salt is present at a concentration of at least 1%.

24. The battery separator as claimed in claim 23, wherein, The concentration of the polysiloxane is between 5,000 and 100,000 ppm.

25. The battery separator as claimed in claim 24, wherein, The concentration of the polysiloxane is between 10,000 and 60,000 ppm.

26. The battery separator as claimed in claim 25, wherein, The concentration of the polysiloxane is between 10,000 and 40,000 ppm.

27. The battery separator as claimed in claim 23, wherein, The polysiloxane has a melting point of 200°C.

28. The battery separator as claimed in claim 23, wherein, The polysiloxane has a melting point greater than or equal to 220°C.

29. The battery separator as claimed in claim 28, wherein, The polysiloxane has a melting point greater than or equal to 230°C.

30. The battery separator as claimed in claim 29, wherein, The polysiloxane has a melting point greater than or equal to 240°C.

31. The battery separator as claimed in claim 23, wherein, The battery separator contains a lubricant, which is a fatty acid salt selected from lithium stearate, sodium stearate, and potassium stearate.

32. The battery separator as claimed in claim 23, wherein, The battery separator contains additives. The additive is at least one of lubricant, plasticizer, nucleating agent, shrinkage reducer, and auxiliary surfactant.

33. The battery separator as described in claim 23, wherein, It also contains an electrolyte additive present in a first surface region of the microporous polymer film and a second surface region opposite to the first surface region of the microporous polymer film.

34. The battery separator as claimed in claim 33, wherein, The electrolyte additives are selected from: SEI modifiers, cathodic protection agents, flame retardant additives, LiPF6 salt stabilizers, overcharge protection agents, lithium deposition agents or solvation enhancers, aluminum corrosion inhibitors, wetting agents, and viscosity modifiers.

35. The battery separator as claimed in claim 33, wherein, The electrolyte additive is selected from borate or ethylene carbonate.

36. A method for manufacturing a battery separator, comprising the following steps: Microporous polymer films are formed from polymer mixtures containing polymers and additives; and A microporous polymer film is coated with a coating mixture containing the additive, which has an ultra-high molecular weight polysiloxane and a fatty acid salt with a melting point above 200°C; the fatty acid salt is present at a concentration of at least 1%.

37. The method of claim 36, wherein, Forming microporous polymer films involves extruding polymer mixtures.

38. The method of claim 36, wherein, Forming microporous polymer films involves co-extruding polymer blends.

39. A method for manufacturing a battery separator, comprising the following steps: Microporous polymer films are formed from polymer mixtures containing polymers and electrolyte additives; and A microporous polymer film is coated with a coating mixture containing the electrolyte additive. The microporous polymer film has an ultra-high molecular weight polysiloxane and a fatty acid salt with a melting point above 200°C; the concentration of the fatty acid salt is at least 1%.

40. The method of claim 39, wherein, The coating also contains ultra-high molecular weight polysiloxane and fatty acid salts with melting points above 200°C; the concentration of the fatty acid salts is at least 1%.

41. The method of claim 39, wherein, Forming microporous polymer films involves extruding polymer mixtures.

42. The method of claim 39, wherein, Forming microporous polymer films involves co-extruding polymer blends.

43. A battery separator for a lithium battery, comprising: At least one microporous separator membrane comprising a plurality of microporous polymer layers, wherein, Compared to adjacent single layers, at least one single layer contains a different additive having an ultra-high molecular weight polysiloxane and a fatty acid salt with a melting point above 200°C; the concentration of the fatty acid salt is at least 1%.

44. The battery separator as claimed in claim 43, wherein, The microporous polymer layer comprises a micron- or nano-layer; and / or, the polymer comprises a homopolymer or copolymer.

45. The battery separator as claimed in claim 43, wherein, The fatty acid salt is selected from lithium stearate, sodium stearate and potassium stearate.

46. ​​The battery separator as claimed in claim 43, wherein, Compared to adjacent single layers, at least one single layer contains a combination of the different additives with polymers of different molecular weights and / or different fillers.

47. The battery separator as claimed in claim 44, wherein, The polymers include different polymer blends.

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