CN111463391A

CN111463391A - Improved coated separator, lithium battery and related methods

Info

Publication number: CN111463391A
Application number: CN202010289011.1A
Authority: CN
Inventors: 张峥明; 迈克尔·B·莱恩; 全寅植; 爱德华·克鲁格; 余翔; 罗尼·E·史密斯; 斯蒂芬·雷纳兹; 马俊青; 丹尼尔·R·亚历山大
Original assignee: Celgard LLC
Current assignee: Celgard LLC
Priority date: 2018-01-22
Filing date: 2019-01-04
Publication date: 2020-07-28
Also published as: CN111463390A

Abstract

The present invention relates to new and improved coatings, layers or treatments for porous substrates, battery separators including coated or treated porous substrates, including coated battery separators, lithium ion batteries including such coatings. According to the present invention, there is disclosed: an improved coating for a porous substrate, said substrate comprising a battery separator, and a new and/or improved coated porous substrate, said substrate comprising a battery separator, a new or improved coating for a porous substrate, said substrate comprising a battery separator, said battery separator comprising at least a matrix material or a polymeric binder, heat resistant particles and at least one component selected from the group consisting of cross-linkers, low temperature shutdown agents, binders and thickeners, a new and/or improved coated porous substrate, said substrate comprising a battery separator, wherein said coating comprises at least a matrix material or a polymeric binder, heat resistant particles and at least one component selected from the group consisting of cross-linkers, low temperature shutdown agents, binders, shutdown agents, friction reducing agents and high temperature agents.

Description

Improved coated separator, lithium battery and related methods

The present application is a divisional application entitled "improved coated separator, lithium battery and related method", application No. 201980004555.4, having application date 2019, 1, 4.

This application relates generally to PCT/US2017/043266 filed on 21/7/2017, the entire contents of which are incorporated herein by reference.

This application claims benefit and priority from U.S. provisional patent application 62/620,087 filed on 2018, 1/22/35, in accordance with 35 U.S. C. § 119(e), and is incorporated herein by reference in its entirety.

Technical Field

The present application relates to new and/or improved coatings for porous substrates, including battery separators or blanking films; and/or to a coated porous substrate comprising a coated battery separator; and/or to batteries or battery cells comprising such coatings or coated separators; and/or to related methods including methods of making and/or using the same. In accordance with at least certain embodiments, the present application is directed to a new or improved coating for a porous substrate, including a battery separator comprising at least a polymeric binder and heat-resistant particles, and which may or may not have additional additives, materials, or components; and/or to new or improved coated porous substrates, including battery separators, wherein the coating comprises at least a polymeric binder and heat-resistant particles and may or may not have additional additives, materials or components. In accordance with at least certain embodiments, the present application is directed to new or improved coatings for porous substrates, including battery separators; and to new and/or improved coated porous substrates, including battery separators; and more particularly to a new or improved coating for porous substrates, including battery separators, comprising at least (i) a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a cross-linking agent, a low temperature shutdown agent, a binder, and/or a thickener; and/or to new and/or improved coated porous substrates, including battery separators, wherein the coating comprises at least (i) a polymeric binder, (ii) heat resistant particles, and (iii) at least one component selected from the group consisting of cross-linking agents, low temperature shutdown agents, binders, thickeners, friction reducers, and/or high temperature shutdown agents. In accordance with at least certain selected embodiments, the present application is directed to new or improved coatings for porous substrates, including battery separators, capacitor separators, fuel cell membranes, textile materials, apparel materials or layers, and filter materials, among others; and to new and/or improved coated or treated porous substrates, including battery separators; and more particularly to a new or improved coating for porous substrates including battery separators, capacitor separators, fuel cell membranes, textile materials, apparel materials or layers, and filter materials, and the like, the coating comprising at least (i) a polymeric binder, (ii) optionally organic and/or inorganic pressure-, dendrite-, and/or heat-resistant particles, and (iii) at least one component selected from the group consisting of cross-linkers, shutdown agents, low temperature shutdown agents, high temperature shutdown agents, binders, X-ray detectable elements, friction reducing agents, and/or thickening agents; and/or to a new and/or improved coated porous substrate, including a battery separator, wherein the coating comprises at least (i) a polymeric binder, (ii) optionally organic and/or inorganic pressure-, dendrite-and/or heat-resistant particles, and (iii) at least one component selected from the group consisting of cross-linkers, shutdown agents, low temperature shutdown agents, high temperature shutdown agents, binders, X-ray detectable elements, friction reducing agents and/or thickeners.

Background

As the technical demands increase, the demands on separator performance, quality and manufacture also increase. Various techniques have been developed to improve the performance of a membrane or a porous substrate used as a separator in a lithium battery.

The application of polymer coatings and ceramic-containing polymer coatings are known methods to improve the thermal safety performance of microporous battery separators in lithium batteries. Such coatings may be applied as a coating or layer on one or both sides of the microporous battery separator membrane in order to promote high temperature stability, control oxidation at the separator-cathode interface of the microporous battery separator membrane, and improve the safety performance of the microporous battery separator membrane in various battery systems, such as lithium ion rechargeable (or secondary) battery systems. U.S. patent No.6,432,586, the entire contents of which are incorporated herein by reference, discloses various ceramic coated separators. In addition, U.S. patent publication No.2014/0045033, the entire contents of which are incorporated herein by reference, discloses various ceramic particle-containing polymer coatings for microporous battery separator membranes that can provide improvements in safety, battery cycle life, and high temperature performance. Such coatings may comprise one or more polymeric binders, one or more inorganic ceramic particles, and an aqueous, non-aqueous or water solvent. Such coatings can be applied using various techniques such as, but not limited to, dip coating, knife coating, gravure coating, curtain coating, spray coating, and the like. In addition, various known ceramic particle-containing polymer coatings may be applied to one or both sides of the microporous cell spacer membrane at different thicknesses, such as, for example, thicknesses of 2-6 microns.

The continued increase in performance standards, safety standards, manufacturing requirements, and/or environmental issues have made the development of new and/or improved coating compositions for battery separators desirable.

One possible major safety issue for lithium ion batteries is thermal runaway. Abusive conditions such as overcharge, overdischarge, and internal short circuits, for example, can result in battery temperatures that are much higher than the battery manufacturer would expect their battery to be used. Shutdown of the battery, for example, stopping of ion flow through, for example, a separator between the anode and the cathode in the event of thermal runaway, is a safety mechanism for preventing thermal runaway. Certain separators in lithium ion batteries provide the ability to shut down at temperatures at least slightly below the temperature at which thermal runaway occurs, while still maintaining their mechanical properties. It is highly desirable to shut down more quickly at lower temperatures and for longer periods of time, for example, to allow the user or device longer to shut down the system.

Another possible major safety issue for lithium ion batteries is the short circuits (hard or soft) that result when the electrodes are in contact with each other. Hard shorts can occur if the electrodes are in direct contact with each other, and can also occur when a large amount (perhaps 100) or very large lithium dendrites growing from the negative electrode are in contact with the positive electrode. The result may be thermal runaway. Soft shorting may occur when small or single (or small amounts, e.g., 5) lithium dendrites grown from the negative electrode contact the positive electrode. Soft shorting can reduce the cycling efficiency of the cell. Certain past ceramic coated separators may be good at preventing hard or soft short circuits, but there is a continuing desire to improve the safety and performance or dendrite blocking function of the separator. For example, it is desirable to maintain this function with increasingly thinner films and coatings.

Therefore, there is a need for improvements in performance, safety, structure, coating, manufacturing, etc., of at least some past separators, films, coating compositions, and/or coated battery separators.

Disclosure of Invention

In accordance with at least selected embodiments, the present application, disclosure or invention herein, provided or embodied thereby, may address previous problems, needs, or issues, and/or may provide or relate to new and/or improved coatings for porous substrates, including battery separators or separator membranes, and/or to coated porous substrates, including coated battery separators; and/or to batteries or battery cells comprising such coatings or coated separators; and/or to related methods including methods of making and/or using the same. In accordance with at least particular embodiments, the present application, disclosure or invention herein, or encompassed thereby, is directed to a new or improved coating for a porous substrate comprising a battery separator comprising at least a polymeric binder and heat-resistant particles and may or may not have additional additives, materials or components; and/or to new or improved coated porous substrates, including battery separators, wherein the coating comprises at least a polymeric binder and heat-resistant particles and may or may not have additional additives, materials or components. In accordance with at least certain embodiments, the present application is directed to new or improved coatings for porous substrates, including battery separators; and to new and/or improved coated or treated porous substrates comprising a battery separator; and more particularly to a new or improved coating for a porous substrate, the substrate comprising a battery separator, the coating comprising at least (i) a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a crosslinking agent, a low temperature shutdown agent, a binder, and a thickener; and/or to a new and/or improved coated porous substrate comprising a battery separator, wherein the coating comprises at least (i) a polymeric binder, (ii) heat resistant particles, and (iii) at least one component selected from the group consisting of cross-linking agents, low temperature shutdown agents, binders, thickeners, friction reducers, high temperature shutdown agents.

In accordance with at least certain selected embodiments, the present invention or application is directed to new or improved coatings for porous substrates, including battery separators, capacitor separators, fuel cell membranes, textile materials, apparel materials or layers, and filter materials, among others; and to new and/or improved coated or treated porous substrates, including battery separators; and more particularly to a new or improved coating for porous substrates including battery separators, capacitor separators, fuel cell membranes, textile materials, apparel materials or layers, and filter materials, and the like, the coating comprising at least (i) a polymeric binder, (ii) optionally organic and/or inorganic pressure-, dendrite-, and/or heat-resistant particles, and (iii) at least one component selected from the group consisting of cross-linkers, shutdown agents, low temperature shutdown agents, high temperature shutdown agents, binders, X-ray detectable elements, friction reducing agents, and/or thickening agents; and/or to a new and/or improved coated porous substrate, including a battery separator, wherein the coating comprises at least (i) a polymeric binder, (ii) optionally organic and/or inorganic pressure-, dendrite-and/or heat-resistant particles, and (iii) at least one component selected from the group consisting of cross-linkers, shutdown agents, low temperature shutdown agents, high temperature shutdown agents, binders, X-ray detectable elements, friction reducing agents and/or thickeners.

In one aspect, described herein is a coating composition, for example, a coating composition for use on at least one side of a porous or microporous substrate or membrane, such as a battery separator, a capacitor separator, a fuel cell membrane, a textile material, a garment material or layer, and/or a filter material. The coating may also be suitable for other uses where its properties, which will be discussed in detail below with respect to the application of the battery separator, will make it a suitable coating choice. The coating composition comprises: (i) a polymeric binder, (ii) heat resistant particles, and (iii) at least one other component selected from the group consisting of (a) a crosslinker, (b) a low temperature shutdown agent, (c) a binder, (d) a thickener, (e) a friction reducer, and (f) a high temperature shutdown agent. In some embodiments, the binder further comprises a solvent that is only water, an aqueous solvent, or a non-aqueous solvent. In some embodiments, the coating composition may also include at least one selected from the group consisting of surfactants, antioxidants, fillers, colorants, stabilizers, defoamers, thickeners, emulsifiers (emulsifier), pH buffers, emulsifiers (emulsification agent), surfactants, anti-settling agents, leveling agents, rheology modifiers, and wetting agents.

In another aspect, a separator describes, for example, a separator for a battery such as a lithium battery, a secondary lithium battery, a lithium ion battery, or a lithium ion secondary battery, the separator comprising a porous substrate and a coating layer formed on at least one surface thereof. The coating composition comprises a coating composition described herein. In some embodiments, the coating is the outermost coating, and in other embodiments, a different coating is formed over the coating, and in this case, the different coating is the outermost layer or may have another different coating formed over it. In some embodiments, a coating comprising the coating composition described herein is applied on both surfaces of the porous substrate, e.g., two opposing surfaces.

In further aspects, composites comprising a separator described herein in direct contact with an electrode for a lithium ion battery, secondary lithium ion batteries comprising a separator described herein, and/or devices or vehicles comprising a separator described herein or secondary lithium ion batteries comprising a separator described herein are described. Secondary lithium ion batteries exhibit at least improved safety and performance.

Drawings

Repeated color and black and white versions of certain figures may be provided.

FIG. 1 is a structural depiction of a copolymer or block copolymer, wherein X is a group capable of creating cross-linking between at least two copolymer or block copolymer chains, such as an epoxide or alkylamine-containing group, and the like, and one embodiment of the copolymer block copolymer is derived from a lactam.

FIG. 2 is a schematic representation of an example of cross-linking between at least two copolymers or block copolymer chains produced by a copolymer block copolymer derived from the lactam in FIG. 1 and the polymer chains are PVP chains, so R in FIG. 1₁、R₂、R₃、R₄And R₅Is hydrogen and Y is 2.

Fig. 3 is a schematic illustration of the selective coverage of heat resistant particles by a polymeric binder. For example, when the ratio of the heat resistant particles to the polymeric binder is lower, the heat resistant particles will be more covered with the binder (e.g., as shown in the right panel of fig. 3), and when the ratio of the heat resistant particles to the polymeric binder is higher, the heat resistant particles will be less covered (e.g., as shown in the left panel of fig. 3).

Fig. 4 is a schematic cross-sectional view of One Side Coating (OSC) and Two Side Coating (TSC) embodiments of the coated substrate or coated separator of the invention, respectively.

Fig. 5 is a graphical representation of one example of turn-off performance, with one axis being resistance and the other axis being temperature.

Fig. 6 is a schematic illustration of the shut-off windows of an uncoated and a side-coated substrate, respectively. The coated substrate has an extended shut-off window.

Fig. 7 is a schematic diagram of a lithium battery.

Fig. 8 is a graph showing the shutdown performance of each of the comparative examples and the inventive examples.

Fig. 9 is a graphical representation of the extended turn-off performance of inventive examples compared to comparative examples.

Fig. 10A, 10B and 10C are graphical representations of the shutdown performance of uncoated and coated PP/PE/PP and PE/PP/PE substrates, respectively.

Fig. 11 is a photographic image showing that by adding a binder to the coating composition, the adhesion of the coating to an electrode, such as a negative electrode, is increased.

FIG. 12 is a photographic image showing the results of a thermal tip hole expansion study. The hot tip test measures the dimensional stability of the separator under spot heating. The test involves contacting the separator with a hot iron tip and measuring the resulting pores. Smaller pores are more desirable.

Fig. 13 is a schematic cross-sectional view of an exemplary ceramic coated separator.

Fig. 14 is a sectional view of a lithium battery in the shape of a column, such as a lithium ion battery or a lithium metal battery.

Detailed description of the preferred embodiments

In accordance with at least selected embodiments, aspects or objects, the present application, disclosure or invention herein provides, encompasses and/or solves previous problems, needs or issues, and/or may provide or relate to new and/or improved coatings or treatments for porous substrates, including battery separators or spacer films; and/or a coated or treated porous substrate comprising a coated battery separator; and/or a battery or battery cell comprising such a coating or coated separator; and/or related methods including methods of making and/or using the same. In accordance with at least certain embodiments, the present application, disclosure or invention herein, or encompassed herein, is directed to a new or improved coating for a porous substrate, including a battery separator, comprising at least a polymeric binder and heat-resistant particles, and which may or may not have additional additives, materials, or components; and/or to new or improved coated porous substrates, including battery separators, wherein the coating comprises at least a polymeric binder and heat-resistant particles and may or may not have additional additives, materials or components. In accordance with at least certain embodiments, the present application relates to new or improved coatings for porous substrates, including battery separators, and to new and/or improved coated or treated porous substrates, including battery separators; and more particularly to a new or improved coating for a porous substrate, the substrate comprising a battery separator, the coating comprising at least (i) a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a crosslinking agent, a low temperature shutdown agent, a binder, and a thickener; and/or to a new and/or improved coated porous substrate comprising a battery separator, wherein the coating comprises at least (i) a polymeric binder, (ii) heat resistant particles, and (iii) at least one component selected from the group consisting of a cross-linking agent, a low temperature shutdown agent, a binder, a thickener, a friction reducer, and a high temperature shutdown agent.

In accordance with at least certain selected embodiments, the present invention or application is directed to or provides new or improved coatings for porous substrates, including battery separators, capacitor separators, fuel cell membranes, textile materials, garment materials or layers, and filter materials, among others; and to or provide new and/or improved coated or treated porous substrates comprising battery separators; and more particularly to or providing a new or improved coating for porous substrates including battery separators, capacitor separators, fuel cell membranes, textile materials, apparel materials or layers, and filter materials, and the like, the coating comprising at least (i) a polymeric binder, (ii) optionally organic and/or inorganic pressure-, dendrite-, and/or heat-resistant particles, and (iii) at least one component selected from the group consisting of cross-linkers, shutdown agents, low temperature shutdown agents, high temperature shutdown agents, binders, X-ray detectable elements, friction reducing agents, and/or thickening agents; and/or to or provide new and/or improved coated porous substrates, including battery separators, wherein the coating comprises at least (i) a polymeric binder, (ii) optionally organic and/or inorganic pressure-, dendrite-and/or heat-resistant particles, and (iii) at least one component selected from the group consisting of cross-linkers, shutdown agents, low temperature shutdown agents, high temperature shutdown agents, binders, X-ray detectable elements, friction reducing agents and/or thickeners.

In accordance with at least selected aspects, objects or embodiments of the present disclosure or invention, see, e.g., examples (1) - (7) and tables 1-4 below, such aspects, objects or embodiments will be described in greater detail below.

Composition comprising a metal oxide and a metal oxide

According to at least one aspect, purpose or embodiment, the coating composition described herein comprises, consists of or consists essentially of: (1) a polymeric binder, optionally comprising a solvent that is only water, an aqueous solvent, or a non-aqueous solvent; (2) heat-resistant particles and/or pressure-resistant particles; and (3) at least one additional component selected from the group consisting of (a) a crosslinking agent, (b) a low temperature shutdown agent, (c) a binder, (d) a thickener, (e) a friction reducer, and (f) a high temperature shutdown agent.

In some embodiments, the coating composition comprises at least two of these additional components, e.g., (a) and (d), (b) and (c), (c) and (e), or (d) and (f). In some embodiments, the coating composition comprises at least three of these additional components, e.g., (a), (b), and (d), (a), (c), and (d) or (c), (e), and (f), and in other embodiments, the coating composition comprises one of these additional components, e.g., (a), (b), (c), (d), (e), and (f). In some embodiments, the coating composition may comprise; two components (a), for example, two crosslinking agents and one component (b). Alternatively, the coating composition may comprise three components (c), e.g. three binders, and one component (d). In some coating compositions, the separately added components may, for example, act as a binder and a low temperature shutdown agent, in other embodiments the binder and the low temperature shutdown agent are different compounds. The coating composition may comprise any possible combination of further components (a), (b), (c), (d), (e) and (f).

(1) Polymer binder

The polymeric binder comprises, consists of, or consists essentially of: at least one of a polymeric material, an oligomeric material, or an elastomeric material, and is not limited thereto. Any polymeric, oligomeric, or elastomeric material may be used that does not interfere with the present disclosure. The binder may be ionically conductive, semiconductive or nonconductive. Any gel-forming polymer suggested for use in a lithium polymer battery or a solid electrolyte battery may be used. For example, the polymeric binder may comprise at least one or two or three selected from the group consisting of polylactam polymers, polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyvinyl acetate (PVAc), carboxymethylcellulose (CMC), isobutylene polymers, acrylics, latex, aramids, or any combination of these materials, and the like.

In some preferred embodiments, the polymeric binder comprises, consists of, or consists essentially of: a polylactam polymer that is a homopolymer, copolymer, block polymer, or block copolymer derived from a lactam. In some embodiments, the polymeric material comprises a homopolymer, a copolymer, a block polymer, or a block copolymer according to formula (1):

wherein R is₁、R₂、R₃And R₄Is an alkyl or aromatic substituent, and R5 is an alkyl substituent, an aryl substituent, or a substituent comprising a fused ring; and wherein preferred polylactams are homopolymers or copolymers wherein the copolymeric group X is derived from vinyl, substituted or unsubstituted alkylvinyl, vinyl alcohol, vinyl acetate, acrylic acid, alkyl acrylate, acrylonitrile, maleic anhydride, maleimide, styrene, polyvinylpyrrolidone (PVP), polyvinylvalerolactam, polyvinylcaprolactam (PVCap), polyamides or polyimides; wherein m is an integer between 1 and 10, preferably between 2 and 4, and wherein the ratio of I to n is 0. ltoreq. I: n.ltoreq.10 or 0. ltoreq. I: n.ltoreq.1. In some preferred embodiments, the lactam-derived homopolymer, copolymer, block polymer, or block copolymer is at least one, at least two, or at least three selected from the group consisting of polyvinylpyrrolidone (PVP), polyvinylcaprolactam (PVCap), and polyvinylvalerolactam.

In a preferred embodiment, the lactam-derived copolymer block copolymer comprises in its backbone groups capable of generating cross-linking between at least two copolymer or block copolymer chains. For example, the group may be an epoxide group or an alkylamine. When the group capable of producing cross-linking between at least two copolymer or block copolymer chains is an epoxide, the epoxide undergoes an epoxidation reaction to produce cross-linking. In some embodiments, it is desirable to add a catalyst. For example, if the group capable of creating cross-links between at least two copolymer or block copolymer chains is an epoxide, a catalyst comprising an alkylamine group may be added, and if the group is an alkylamine, a catalyst comprising an epoxide group may be added. The copolymers or block copolymers described in this paragraph can have a structure as shown in FIG. 1, where X is a group capable of producing cross-linking between at least two copolymer or block copolymer chains, for example, an epoxide-containing or alkylamine-containing group. One embodiment of the lactam-derived copolymer block copolymer described in this paragraph is shown in FIG. 1.

An example of the cross-linking between at least two copolymers or block copolymer chains produced by the lactam-derived copolymer block copolymer in fig. 1 is shown in fig. 2.

In one embodiment, the polymeric coating may comprise a polylactam of formula (1):

wherein R is₁、R₂、R₃And R₄Is an alkyl or aromatic substituent, R₅Is alkyl, aryl or a fused ring; and

preferred polylactams among these may be homopolymers or copolymers wherein the copolymeric group X is derived from vinyl, substituted or unsubstituted alkylvinyl, vinyl alcohol, vinyl acetate, acrylic acid, alkyl acrylate, acrylonitrile, maleic anhydride, maleimide, styrene, polyvinylpyrrolidone (PVP), polyvinylvalerolactam, polyvinylcaprolactam (PVCap), polyamides or polyimides;

wherein m is an integer of 1 to 10, preferably 2 to 4,

and wherein the ratio of I to n is 0. ltoreq. I: n. ltoreq.10 or 0. ltoreq. I: n. ltoreq.1.

In one embodiment, the polymeric coating may comprise a polylactam according to formula (2) and a catalyst:

wherein R is₁、R₂、R₃And R₄Is an alkyl or aromatic substituent;

R⁵is alkyl, aryl or a fused ring;

wherein m is an integer of 1 to 10, preferably 2 to 4,

and wherein the ratio of I to n is 0. ltoreq. I: n. ltoreq.10 or 0. ltoreq. I: n. ltoreq.1,

x is an epoxide or an alkylamine.

In FIG. 2, the polymer chain is a PVP chain, so R in FIG. 1₁、R₂、R₃、R₄And R₅Is hydrogen and Y is 2. The use of a lactam-derived copolymer or block copolymer comprising in its backbone a group capable of creating cross-linking between at least two copolymer or block copolymer chains can improve thermal stability, improve electrolyte stability, improve wetting and CV performance of the resulting coating.

In another preferred embodiment, the polymeric binder comprises, consists of, or consists essentially of: polyvinyl alcohol (PVA). The use of PVA may result in a low curl coating that helps the substrate to which it is applied to remain stable and flat, e.g., helps prevent curling of the substrate. PVA may be added in combination with any of the other polymeric, oligomeric, or elastomeric materials described herein, particularly if low curl is desired.

In another preferred embodiment, the polymeric binder comprises, consists of, or consists essentially of: an acrylic resin. The type of acrylic resin is not particularly limited and may be any acrylic resin that does not contradict the purpose described herein, for example, to provide a new and improved coating composition that may be used, for example, to manufacture a battery separator having improved safety. For example, the acrylic resin may be at least one or two or three or four selected from the group consisting of polyacrylic acid (PAA), polymethyl methacrylate (PMMA), Polyacrylonitrile (PAN), polymethyl acrylate (PMA).

In other preferred embodiments, the polymeric binder comprises, consists of, or consists essentially of: carboxymethyl cellulose (CMC), an isobutylene polymer, a latex, or a combination of any of these. These may be added alone or together with any other suitable oligomeric, polymeric or elastomeric material.

In some embodiments, the polymeric binder may comprise a water-only solvent, an aqueous or water-based solvent (aquous or water-based solvent), and/or a non-aqueous solvent. When the solvent is water, in some embodiments, no other solvent is present. The aqueous or water-based solvent can comprise a majority (greater than 50%) of water, greater than 60% of water, greater than 70% of water, greater than 80% of water, greater than 90% of water, greater than 95% of water, or greater than 99% of water, but less than 100% of water. The aqueous solvent or the aqueous solvent may contain a polar or non-polar organic solvent other than water. The non-aqueous solvent is not limited and can be any polar or non-polar organic solvent compatible with the purposes described herein. In some embodiments, the polymeric binder contains only trace amounts of solvent, in other embodiments it contains more than 50% solvent, sometimes more than 60%, sometimes more than 70%, sometimes more than 80%, etc.

The ratio of heat resistant particles to polymeric binder in the coating composition is in some embodiments 50:50 to 99:1, in other embodiments 70:30 to 99:1 or 90:1 to 98:2, and in further embodiments 90:10 to 99: 1. This ratio affects the coverage of the heat resistant particles with the polymeric binder. For example, when the ratio of heat resistant particles to polymeric binder is lower, the heat resistant particles will be more covered with binder (e.g., as shown in the right panel of fig. 3), and when the ratio of heat resistant particles to polymeric binder is higher, the heat resistant particles will be less covered (e.g., as shown in the left panel of fig. 3).

In a preferred embodiment, at least one of the heat resistant particles is coated or partially coated with a polymeric binder. For example, in some embodiments, 0.01 to 99.99% of the surface area of at least one of the heat resistant particles (or the surface area of all of the heat resistant particles) is coated with a binder. In some embodiments, 0.01 to 99.99% of the total surface area of the heat resistant particles in the composition is coated with a polymeric binder.

(2) Heat-resistant and/or pressure-resistant particles

In another aspect, heat-resistant particles are added to the coating compositions described herein. The size, shape, chemical composition, etc. of these heat-resistant particles are not limited. The heat-resistant particles may comprise an organic material, an inorganic material, such as a ceramic material, or a composite material comprising both inorganic and organic materials, two or more organic materials, and/or two or more inorganic materials.

In some embodiments, heat resistant means that the material comprised of particles, which may comprise a composite material comprised of two or more different materials, does not undergo substantial physical changes, e.g., deformation, at a temperature of 200 ℃. Exemplary materials include alumina (Al)₂O₃) Silicon dioxide (SiO)₂) Graphite, and the like.

Non-limiting examples of inorganic materials that can be used to form the heat-resistant particles disclosed herein are as follows: iron oxide, silicon dioxide (SiO)₂) Alumina (A1)₂O₃) Boehmite (Al (O) OH), zirconium dioxide (ZrO)₂) Titanium dioxide (TiO)₂) Barium sulfate (BaSO)₄) Barium metatitanate (BaTiO)₃) Aluminum nitride, silicon nitride, calcium fluoride, barium fluoride, zeolite, apatite, kaolin, mullite, spinel, olivine, mica, tin dioxide (SnO)₂) Indium tin oxide, transition metal oxides, graphite, carbon, metals, X-ray detectable materials, kaolin, calcined clay, kaolinite, metastable alumina, mixtures or blends thereof, and any combination thereof.

Non-limiting examples of organic materials that can be used to form the heat resistant particles disclosed herein are as follows: polyimide resins, melamine resins, phenolic resins, Polymethylmethacrylate (PMMA) resins, polystyrene resins, Polydivinylbenzene (PDVB) resins, carbon black, graphite, and any combination thereof.

The heat-resistant particles may be round, irregular, flaky, etc. The average particle size of the heat-resistant material is in the range of 0.01-5 micrometers, 0.03-3 micrometers, 0.01-2 micrometers and the like.

As noted above, in preferred embodiments, at least one of the heat resistant particles added to the coating compositions described herein is coated or partially coated with a polymeric binder and/or with a wax. In other embodiments, the heat-resistant particles can be coated or partially coated (in addition to or as an alternative to being coated or partially coated with a polymeric binder) with a compatibilizer, e.g., a material that makes the particles more miscible with the polymeric binder. In general, the heat resistant particles can be coated or partially coated in any manner that is not inconsistent with the objectives described herein.

Without wishing to be bound by theory, oxidation or reduction reactions may occur during the formation stage of a lithium ion battery or during charging or discharging of a lithium ion battery, and these reactions may generate byproducts that are harmful to the battery system. The coating compositions described herein can slow or can prevent oxidation reactions that occur with uncoated polypropylene (PP) or Polyethylene (PE) porous substrates, such as battery separators. The heat-resistant particles contain, for example, aluminum oxide (Al)₂O₃) Are chemically inert and do not undergo oxidation with the electrolyte. The improved oxidative stability can be obtained by placing the coated side of the separator described herein facing or away from the positive electrode or positive electrode.

(3) Added components

The coating composition comprises at least one or two or three of (a) a crosslinking agent, (b) a low-temperature shutdown agent, (c) a binder, (d) a thickener, (e) a friction reducing agent, and (f) a high-temperature shutdown agent, and the like.

(a) Crosslinking agent

In another aspect, at least one crosslinking agent may be added to the coating composition. The crosslinking agent is not limited and includes any compound capable of forming a link between two or more polymeric chains in the coating composition as long as the compound does not interfere with the purpose described herein. For example, the crosslinking agent may be a compound having a plurality of reactive groups, such as epoxy groups, acrylate groups, and the like. For example, the crosslinking agent can comprise two, three, four, five, etc. reactive groups. In some embodiments, polyepoxy-based crosslinkers having three or more reactive groups are preferred.

In a preferred embodiment, the cross-linking agent may be part of a polymeric material, an oligomeric material or an elastomeric material in a polymeric binder, for example, in the backbone. For example, the crosslinking agent can be an epoxide group derived from a copolymer or block copolymer of lactams as shown in FIG. 1.

The crosslinking agent may also be a monomer species that is independent of the polymeric, oligomeric, or elastomeric material in the polymeric binder. Some examples of crosslinking agents include the following: difunctional acrylates, trifunctional acrylates including pentaerythritol triacrylate, multifunctional acrylates such as pentaerythritol tetraacrylate, ethoxylated (4) pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and ethoxylated dipentaerythritol hexaacrylate, diepoxides including, for example, 1, 3-diepoxybutane, bis [ (4-glycidoxy) phenyl ] methane and its isomers, 1, 4-butanediol diglycidyl ether, 1,2,7, 8-diepoxyoctane, 1, 2-cyclohexanedicarboxylic acid diglycidyl ester, N-diglycidyl-4-glycidoxyaniline, triepoxides including tris (2, 3-epoxypropyl) isocyanurate and tris (4-hydroxyphenyl) methane triglycidyl ether, mixtures thereof, and mixtures thereof, Dimethacrylates, trimethacrylates, and multifunctional methacrylates.

In some preferred embodiments, the crosslinking agent may be an epoxy or epoxy group-containing molecule. For example, it may be a di-, tri-or multifunctional epoxide. To form crosslinks between two or more polymers in a coating, the crosslinking agent may react with nucleophilic groups in the polymers. For example, nucleophilic groups containing N, S or O. For example, the nucleophilic group can be allylamine or an alkyl alcohol.

The crosslinking agent may be added in any amount consistent with the purpose described herein. In some preferred embodiments, the amount of crosslinker is added on a ppm scale, e.g., up to 50,000ppm, up to 10,000ppm, up to 5,000ppm, etc., relative to the total coating composition.

Upon addition of the crosslinking agent, in some embodiments, a crosslinking agent or catalyst may be added, which may be initiated or catalyzed by the added crosslinking agent, e.g., crosslinking of two polymer chains. The crosslinking agent may be sensitive to heat, light or chemical environment (e.g., pH), for example, a crosslinking agent (cross-linking agent) or a crosslinking agent (cross-linker) may initiate or catalyze crosslinking of more than one polymer chain in the coating composition in response to heat, light irradiation or a change in pH.

Upon addition of a cross-linking agent to the coating compositions described herein, the inventors of the present application have found that the resulting coating and battery separators comprising the coating (on one or both sides thereof) exhibit a number of beneficial properties. These properties include lower MD and TD shrinkage even at higher temperatures, for example, temperatures of l80 ℃. When a crosslinker is added to the coating composition described herein, a coating with higher thermal stability results.

Shrinkage was measured by: a test sample, such as a coated porous substrate, is placed between two sheets of paper, which are then sandwiched together to hold the sample between the papers and suspended in an oven. For the "150 ℃ for 1 hour" test, the sample was placed in an oven at 150 ℃ for 1 hour. After the specified heating time in the oven, each sample was removed and attached to the flat reverse side using double sided tape to make the sample flat and smooth for accurate length and width measurements. Shrinkage was measured in both the Machine Direction (MD) and Transverse Direction (TD) (perpendicular to the MD) directions and is expressed as% MD shrinkage and% TD shrinkage. For the "180 ℃ 10 min" test, the samples were placed in a 180 ℃ oven for 10 min and then tested as described for the "150 ℃ 1 h" test above. For the "180 ℃ 20 min" test, the samples were placed in a 180 ℃ oven for 20 min and then tested as described for the "150 ℃ 1 h" test above. Shrinkage can be measured for one-side coated porous substrates or two-side coated porous substrates.

In some preferred embodiments, the coating composition comprising the crosslinker will not contain inorganic components. One benefit of such embodiments may be the ability to form a thin coating such that the thickness of the coated porous substrate is not thicker or substantially thicker than the uncoated porous substrate. For example, the coated porous substrate may be less than 500nm, less than 400nm, less than 300nm, less than 200nm, less than 100nm, less than 50nm, or less than 1nm thicker than the uncoated porous substrate. This is possible, particularly in embodiments where no inorganic component is added, because the coating enters the pores in the microporous membrane. In embodiments where an inorganic component is added, the inorganic component may block or cover or partially block or cover the pores.

(b) Low temperature shutdown agent

In another aspect, a low temperature shutdown agent is added to the coating composition described herein. The type of cryogenic agent used is not limited so long as it does not interfere with the objectives described herein, such as providing a coating composition that can be used to make safer lithium ion batteries. In some embodiments, the low temperature shutdown agent has a melting temperature that is lower than the melting temperature of the porous film to which the coating composition is applied (or intended to be applied). For example, if the porous film melts around l35 ℃, the melting temperature of the low temperature shutdown agent is lower than l35 ℃.

In some embodiments, the low temperature shutdown agent has a melting point in the range of 80 ℃ to 130 ℃, sometimes in the range of 90 ℃ to l20 ℃, sometimes in the range of l00 ℃ to 120 ℃, and the like.

The low temperature shutdown agent can be particles with average particle size in the range of 0.1-5.0 micrometers, 0.2-3.0 micrometers, 0.3-1.0 micrometers, and the like. The particles may be coated, uncoated or partially coated.

In some preferred embodiments, the low temperature shutdown agent may be particles comprising waxes, oligomers, and/or Polyethylene (PE), such as low density PE, and the like.

The particles may be coated, uncoated or partially coated. For example, they may be coated with latex and/or the polymeric binders disclosed herein. In some embodiments, these coated low temperature shutdown agents may be coated with a high temperature shutdown agent described in more detail below.

The inventors of the present application found that coating a battery separator with a coating composition comprising the low temperature shutdown agent described herein results in a better separator, particularly from the viewpoint of safety. Without wishing to be bound by any particular theory, it is believed that this improved safety is due to the extended shutdown window discussed further herein, thereby allowing shutdown to begin at a lower temperature than the shutdown window of an uncoated separator or a coated separator in which the coating does not contain a low temperature shutdown agent.

(c) Adhesive agent

In another aspect, a binder may be added to the coating compositions herein. The compound used as the binder is not limited as long as it does not contradict the purpose described herein. In some embodiments, the addition of a binder to a coating composition described herein results in a coating having higher adhesion to a battery electrode, e.g., a lithium battery electrode, as compared to a coating formed from a similar coating composition in which no binder is added. The binder increases the "tack" and/or tackiness of the coating formed from the coating composition described herein. Adhesion between the heat-resistant particles in the coating and adhesion of the coating formed from the coating composition described herein to the porous substrate described herein can also be improved. For example, even in embodiments where the porous substrate has not been pretreated to improve the adhesion of the coating, the coating-to-porous substrate bond strength can be greater than l0N/m, greater than l2N/m, greater than 14N/m, greater than l6N/m, greater than l8N/m, or greater than 20N/m. Such pre-treatments may include corona treatment, plasma treatment, stretching, surfactant treatment/coating, and any other surface treatment and/or coating intended to improve the adhesion of the substrate to the coating. However, while it is not necessary to achieve excellent adhesive strength between the porous substrate and the coating, the use of such pre-treatments is not excluded. In some embodiments, the binder may be polyvinylpyrrolidone (PVP) or a thermoplastic fluoropolymer, such as polyvinylidene fluoride (PVdF or PVdF).

One way to measure the adhesion of the coating to the battery electrode is as follows: the coated battery separator described herein was placed between the electrodes, the electrolyte was injected into the space between the electrodes, and the electrode-coated separator composite was hot-pressed at 90 ℃ for 12 hours. Subsequently, the composite is disassembled, for example, the separator is separated from the electrode, and the separator is observed. If a large amount of black material as an electrode material is observed on the separator, this indicates higher adhesion between the separator and the electrode. The lower the amount of black material or electrode material, the lower the adhesion.

In some embodiments, the adhesive may comprise, consist of, or consist essentially of: "Dry-tack" polymers. As used herein, a "dry-tack" polymer is any polymer that imparts high or low tack to a coating. The high tack coating is more difficult to separate after contact with another surface with which it forms a bond. The less viscous coating is more easily separated and repositioned after contact with another surface with which it forms a bond. A coating having adhesion may be beneficial for battery separators used in stacked or prismatic battery cells. Once the separator is in its proper position in the cell, it helps prevent the separator from moving. "Dry-tack" polymers are characterized by their glass transition temperature. In some embodiments, the glass transition temperature may be less than l00 ℃, and preferably less than 70 ℃.

In some embodiments, the adhesive may comprise, consist of, or consist essentially of: a "wet-stick" polymer that swells and gels in a non-aqueous electrolyte. The "wet-stick" polymer described herein is not limited and can be any polymer that absorbs electrolyte, swells or increases in size as it absorbs electrolyte, and/or becomes gel-like as it absorbs electrolyte. The electrolyte may be any electrolyte suitable for use in a secondary battery, which may include, but is not limited to, an electrolyte in which the solvent is DEC, PC, DMC, EC, or a combination thereof. The wet adhesion polymer will also increase the adhesion of the coating to the negative or positive electrode of the secondary battery when wet. The wet tack polymer may be a fluoropolymer, such as PvdF or PvdF-HFP. The HFP content of PVDF-HFP may be 1 wt% to 50 wt% based on the total weight of the polymer. It may also be 1 to 40 wt%, 1 to 30 wt%, 1 to 20 wt%, 1 to 15 wt%, 1 to 10 wt%, or 1 to 5 wt%. In some embodiments, the wet adhesion polymer may be used in a coating placed in contact with the positive electrode of a secondary battery, such as a lithium ion battery. In such embodiments, the side of the separator in contact with the negative electrode may comprise a coating comprising or consisting essentially of CMC, styrene-butadiene rubber (SBR), or acrylic.

In some embodiments, the adhesive comprises, consists of, and combinations of a wet-stick polymer and a dry-stick polymer.

(d) Thickening agent

In another aspect, a thickener may be added to the coating compositions described herein. The thickener used is not limited and may be any thickener that does not negate the purpose described herein. In some embodiments, thickeners are added to adjust the viscosity of the coating compositions described herein. An exemplary thickener is, for example, carboxymethylcellulose (CMC).

(e) Friction reducing agent

In another aspect, a friction reducer may be added to the coating compositions described herein. The friction reducer is not limited and can be any friction reducer that does not oppose the objectives described herein. For example, in some embodiments, the addition of a friction reducer can result in a reduction in pin removal force and/or a reduction in the coefficient of friction when comparing a film formed from a coating composition containing the friction reducer to a film formed from a coating composition without the addition of the friction reducer. In some embodiments, the coatings formed from the coating compositions described herein are "tacky" or adhere well to the electrode when wet, e.g., with an electrolyte such as PVDF or PVDF: HFP, and have good pin removal force when dried. For example, in some embodiments, the film formed from the coating composition containing the friction reducer has a pin removal force of less than or equal to 7l00g, in some embodiments, a pin removal force of less than 6500g, and in some embodiments, a pin removal force of less than 6000 g. In some embodiments, the coefficient (static) ranges from 0.2 to 0.8, sometimes from 0.3 to 0.7, sometimes from 0.4 to 0.6, and sometimes from 0.3 to 0.5.

The following procedure for measuring 'pin removal force (g)' was used to quantify pin removal performance.

A separator (comprising, consisting of, or consisting essentially of a porous substrate having an applied coating on at least one surface thereof) is wound around a pin (or core or mandrel) using a battery winder. The pin is a two (2) piece cylindrical mandrel with a 0.16 inch diameter and a smooth outer surface. Each member has a semi-circular cross-section.

Spacers are provided on the pins as described below. The initial force (tangential) on the separator was 0.5kgf, and then the separator was wound at a speed of ten (10) inches in twenty four (24) seconds. During winding, the tension roller engages the separator wound on the mandrel. The tension rollers included an 5/8 "diameter roller on the side opposite the separator feed, a 3/4" pneumatic cylinder applying 1 bar air pressure (when engaged), and a 1/4 "rod interconnecting the roller and cylinder.

The separator consisted of two (2)30mm (width) × 10 "pieces of film to be tested five (5) such separators were tested, the results averaged, and the average recorded, each piece was spliced to a separator feed roll on the winder with an amount of overlap of 1", from the free end of the separator, the distal splice end, ink marks were made at 1/2 "and 7", 1/2 "mark was aligned with the distal side of the pin (i.e., the side adjacent to the tension roll), the separator was engaged between the pieces of the pin, and winding was started from the engaged tension roll, when the 7" mark was about 1/2 "from the jelly roll (wound on the pin), the separator was cut at that mark, and the free end of the separator was secured to the jelly roll with a piece of tape (1" wide, 1/2 "overlap), -the jelly roll (i.e., the pin with separator thereon) was removed from the winder.

The jelly roll was placed in a tensile strength tester (i.e., Chatillon Model TCD500-MS from Chatillon corporation, greenboro, N.C.) with a load cell (50 lbs × 0.02.0.02 lbs.; Chatillon DFGS 50.) the strain rate was 2.5 inches/minute and the data from the load cell was recorded at a rate of 100 points/second.

COF (coefficient of friction) is statically measured according to JIS P8147 entitled "method for determining the coefficient of friction of paper and board".

In some preferred embodiments, the friction reducer is a fatty acid salt. For example, the friction reducer may be a metal stearate, such as lithium stearate, calcium stearate, and the like. Other possible friction reducers include silicones, fluororesin waxes (e.g., paraffin waxes, microcrystalline waxes, low molecular weight polyethylene and other hydrocarbon waxes), fatty acid esters (e.g., methyl stearate, stearyl stearate, monoglyceryl stearate), fatty amides (e.g., stearamide, palmitamide, methylene bis stearamide), and any combination of the foregoing friction reducers.

(f) High temperature shutdown agent

According to another aspect, a high temperature shutdown agent is added to the coating composition described herein. The type of high temperature agent used is not limited so long as it does not interfere with the objectives described herein, such as providing a coating composition that can be used to make safer lithium ion batteries. In some embodiments, the high temperature shutdown agent has a melting temperature that is higher than the melting temperature of the porous film on which (or intended to) apply the coating composition. For example, if the porous film melts at about 135 ℃, the melting temperature of the high temperature shutdown agent is higher than 135 ℃.

In some embodiments, the high temperature shutdown agent has a melting point in the range of 140 ℃ to 220 ℃, sometimes 150 ℃ to 200 ℃, sometimes 160 ℃ to 190 ℃, sometimes 170 ℃ to 180 ℃, and the like.

The high temperature shutdown agent can be particles with average particle size in the range of 0.1-5.0 micrometers, 0.2-3.0 micrometers, 0.3-1.0 micrometers, and the like. The particles may be coated, uncoated or partially coated.

In some preferred embodiments, the high temperature shutdown agent may be particles comprising polyvinylpyrrolidone (PVP) or polyvinylidene fluoride (PVdF). The particles may be coated, uncoated or partially coated. For example, they may be coated with latex and/or the polymeric binders described herein. In some embodiments, the coated particles may be coated with a low temperature shutdown agent as described above.

The inventors of the present application have found that coating a battery separator with a coating composition comprising the high temperature shutdown agent described herein, leads to a better separator, particularly from the viewpoint of safety. Without wishing to be bound by any particular theory, it is believed that this improved safety is due to the extension of the shutdown window discussed further herein to higher temperatures than the shutdown window of an uncoated separator or a coated separator in which the coating does not contain a high temperature shutdown agent.

4) Optional additional Components

In another aspect, one or more of the following additional components are optionally added: the paint consists of a surfactant, an antioxidant, a filler, a coloring agent, a stabilizer, a defoaming agent, a thickening agent, an emulsifier, a pH buffering agent, an emulsifier, a surfactant, an anti-settling agent, a leveling agent, a rheology modifier and a wetting agent. Two or more, three or more, four or more, etc. of these optional additional components may also be added to the coating compositions described herein. Further, depending on the need and the choice of particles or fillers, X-ray detectable elements may also be added. For example, barium sulfate may be added or may replace a portion of the particles or filler. In one embodiment, up to 30% of the particles may be replaced with an X-ray detectable element such as barium sulfate.

Separator

In another aspect, described herein is a separator comprising, consisting of, or consisting essentially of a porous substrate and a coating formed on at least one surface of the porous substrate. A one-side coated separator and a two-side coated separator according to some embodiments herein are shown in fig. 4.

The coating may comprise, consist of, or consist essentially of, and/or be formed from any of the coating compositions described above. The coating may be wet, dry, crosslinked, uncrosslinked, and the like. The coating may be applied over the PVD layer, or the PVD layer may be applied over the coating. The coating may be applied over the adhesive layer, or the adhesive layer may be applied over the coating.

The new and/or improved separators described herein may have or exhibit one or more of the following characteristics or improvements in the case of a lithium battery having a chemical vapor deposition (CCVD) or physical vapor deposition (PCS) of the same or different type of inorganic barrier coating (CCVD) or physical barrier coating (PCS) of the same or physical barrier coating (PCS) of the same or physical barrier coating (PCS) of the same or physical barrier coating) or physical barrier coating (PCS) of the same or physical barrier coating (PCS) or physical barrier coating, the same or physical barrier Coating (CVD) or physical barrier coating (PCS) or physical barrier Coating (CVD) of the same or physical barrier Coating (CVD) or physical barrier coating (PCS) or physical barrier Coating (CVD) of the same or physical barrier coating, the physical barrier Coating (CVD) or CVD) of the physical barrier coating, the same or physical barrier coating (CVD or physical barrier coating (PCS) or physical barrier Coating (CVD) of the same or physical barrier Coating (CVD) or physical barrier coating, the physical barrier coating (PCS) of the physical barrier coating, or.

The new and/or improved coated separator may have excellent quality and uniformity, providing good manufacturing yield. The new and/or improved coated separator may provide a battery with improved capacity and improved cycling capability. It may have fewer defects, such as fewer gel defects and/or fewer crater defects, than other known coated separators. The improved and/or coated separator may have improved adhesion of the coating to the porous substrate. The adhesive strength may be greater than l0N/m, greater than 12N/m, greater than l4N/m, greater than l6N/m, greater than 18N/m, or greater than 20N/m.

The new and/or improved coated porous substrates (or separators) may also have improved safety by exhibiting extended shut-off windows, particularly as compared to the shut-off windows of the porous substrate itself (e.g., an uncoated porous substrate or separator). The extended shutdown window of the new and/or improved separators disclosed herein may extend between about 80 ℃ to about 200 ℃ compared to the window of about 130 ℃ to 175 ℃ of the matrix itself. The extended off-window of the new and/or improved substrate is also stable, e.g., a constant or relatively constant resistance across the separator is measured over the entire window. For example, in some embodiments, the measured resistance across the separator remains greater than 10,000 ohms/cm throughout the window². This is considered to be stable. Sometimes, the measured resistance across the separator is even as high as 100,000 ohms/cm within the extended off window of the new and/or improved separator disclosed herein². The initial shut-off of the new and/or improved separators disclosed herein is also rapid. Sometimes, during initial shutdown, as the temperature increases between 1 and 5 degrees Celsius,measured resistance across the separator from less than 10 ohm/cm²Increase to more than 10,000 ohm/cm². For example, the resistance may be from 5 ohm/cm at l20 ℃²Becomes more than 10,000 ohm/cm at 125 DEG C². Sometimes, only a 4, or 3, or 2, or 1 degree temperature increase is necessary in order for this increase in resistance to occur.

Preferred thermal shutdown characteristics are a lower starting or starting temperature, a faster or more rapid shutdown speed, and a sustained, consistent, longer or extended thermal shutdown window. In a preferred embodiment, the turn-off speed is at least 2000ohms (Ω). cm²Second or 2000ohms (omega) · cm²And upon turn off, the resistance across the separator increases by at least two orders of magnitude. Fig. 5 shows an example of the shutdown performance.

The shutdown window as described herein generally refers to a time/temperature window spanned by the onset of shutdown (initiation) or initiation (onset), e.g., the time/temperature at which the separator first begins to melt sufficiently to close its pores, resulting in, for example, cessation or slowing of ion flow between the negative and positive electrodes and/or an increase in resistance across the separator, until the separator begins to decompose (e.g., decompose), resulting in recovery of ion flow and/or a decrease in resistance across the separator. Fig. 6 shows an example of an extended shutdown window as described herein.

Fig. 6 shows that the shut-off window of a coated porous substrate according to embodiments described herein is extended compared to the shut-off window of the porous substrate itself, e.g., prior to coating with one of the coating compositions described herein. For uncoated porous substrates, the onset or onset of shutdown occurred at about 135 ℃ and occurred earlier after coating. Without wishing to be bound by any particular theory, this may be due to the addition of the low temperature shutdown agents described herein to the coating compositions and/or coatings described herein. The low temperature shutdown agent may melt before the porous substrate and fill or partially fill its pores, resulting in an early (lower temperature) onset of shutdown. Fig. 6 also shows that the duration of shutdown extends from 170 ℃ in the uncoated porous substrate to about 190 ℃ after coating. Without wishing to be bound by any particular theory, this may result from the addition of the high temperature shutdown agents described herein to the coatings and coating compositions described herein. High temperature shutdown agents may degrade at higher temperatures than the porous substrate itself. In some embodiments described herein, only the shutdown initiation temperature (extended window) is reduced, in other embodiments only the high temperature endpoint (extended window) of the shutdown window is increased, and in some embodiments both the upper endpoint and the lower endpoint of the shutdown window are extended, for example, as shown in fig. 6.

Shutdown can be measured using a resistance test that measures the resistance of the blanking film as a function of temperature. Resistance (ER) is defined as the ohm-cm of a separator filled with electrolyte²Is the resistance value in units. During the Electrical Resistance (ER) test, the temperature may be increased at a rate of 1 to 10 ℃ per minute. When thermal shutdown of the battery separator occurs, the ER reaches about 1,000 to 10,000 ohm-cm²High resistance levels of an order of magnitude. The combination of a lower onset temperature for thermal shutdown and an extended shutdown temperature duration increases the sustained "window" of shutdown. A wider thermal shutdown window may improve battery safety by reducing the likelihood of a thermal runaway event and the likelihood of a fire or explosion.

One exemplary method of measuring the shutdown performance of the separator is to 1) place a few drops of electrolyte on the separator to saturate it and place the separator in the test cell, 2) ensure that the hot press is below 50 ℃, if so, place the test cell between platens (plates) and slightly compress the platens so that only slight pressure is applied to the test cell (< 50lbs for the Carver "C" press), 3) connect the test cell to an R L C bridge and begin recording the temperature and resistance, when a stable baseline is reached, then begin raising the temperature of the hot press at a rate of 10 ℃/min using a temperature controller, 4) shut down the heated platens when the maximum temperature is reached or when the separator resistance drops to a low value, and 5) open the platens and remove the test cell.

(1) Porous substrate

The porous substrate used in the separator described herein is not limited, and may be any porous substrate that does not contradict the purpose described herein. For example, the porous substrate may be any porous substrate that can be used as a battery separator. The porous substrate may be a macroporous substrate, a mesoporous substrate, a microporous substrate, or a nanoporous substrate. In some preferred embodiments, the porous substrate has a porosity of 20 to 90%, 40 to 80%, 50 to 70%, etc. Porosity is measured using ASTM D-2873 and is defined as the percentage of void space, e.g., porosity, in a region of a porous substrate, which is measured in the Machine Direction (MD) and Transverse Direction (TD) of the substrate. In some embodiments, the porous substrate has a JIS Gurley of 0.5 to 1000 seconds, in some embodiments, a JIS GUSGuley of 100 to 800 seconds, in other embodiments, a porous JIS Gurley of 200 to 700 seconds, and in other embodiments, a porous JIS Gurley of 300 to 600 seconds. Gurley is defined herein as japanese industrial standard (JIS Gurley), and is measured herein using an OHKEN permeability tester. JIS Gurley is defined as the time in seconds required for 100cc of air to pass through a 1-square inch membrane under a constant pressure of 4.9 inches of water. In some embodiments, the pores are circular, e.g., a sphericity factor of 0.25-8.0, elliptical, oval, or the like.

The fluorocarbon may include Polytetrafluoroethylene (PTFE), Polychlorotrifluoroethylene (PCTFE), Fluorinated Ethylene Propylene (FEP), Ethylene Chlorotrifluoroethylene (ECTFE), Ethylene Tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), Perfluoroalkoxy (PFA) resins, copolymers thereof, and co-polymers thereofPolyamides may include, but are not limited to, polyamide 6, polyamide 6/6, nylon 10/10, polyphthalamide (PPA), copolymers thereof, and blends thereof.polyester may include polyester terephthalate (PET), polybutylene terephthalate (PBT), poly-1, 4-cyclohexanedimethylene terephthalate (PCT), polyethylene naphthalate (PEN), and liquid crystal polymer (L CP). polythioethers include, but are not limited to, polyphenylene sulfide, polyethylene sulfide, copolymers thereof, and blends thereof.polyvinyl alcohol includes, but is not limited to, ethylene vinyl alcohol, copolymers thereof, and blends thereof₂O₃、SiO₂Etc.), including polymers, copolymers, and block polymers thereof, as well as blends, mixtures, or combinations thereof.

The porous substrate may be a multilayer film or a layer in a separator structure, a laminate, a composite, or the like. For example, the porous substrate (or coated base film) may be one layer of a multilayer film or separator structure, such as a bi-layer or tri-layer film of a laminate or composite, e.g., a polymer film combined with a nonwoven material such as glass and/or synthetic nonwoven materials and the like.

The porous substrate may include other components. For example, these ingredients may include: fillers (inert particles to reduce the cost of the porous substrate, but not significantly affect the manufacture of the porous substrate or its physical properties), antistatic agents, antiblocking agents, antioxidants, and lubricants (to facilitate manufacture), and the like.

Various materials may be added to the polymer to alter or improve the properties of the porous substrate, such materials include, but are not limited to, (1) polyolefins or polyolefin oligomers having a melting temperature of less than 130 ℃, (2) mineral fillers including, but not limited to, calcium carbonate, zinc oxide, diatomaceous earth, talc, kaolin, synthetic silica, mica, clay, boron nitride, silica, titanium dioxide, barium sulfate, aluminum hydroxide, and magnesium hydroxide, and the like, and blends thereof, (3) elastomers including, but not limited to, ethylene-propylene (EPR), ethylene-propylene-diene (EPDM), styrene-butadiene (SBR), Styrene Isoprene (SIR), Ethylidene Norbornene (ENB), epoxy resins, and polyurethanes and blends thereof, (4) wetting agents including, but not limited to, ethoxylated alcohols, primary polymeric carboxylic acids, glycols (e.g., polypropylene glycol and polyethylene glycol), functionalized polyolefins, and the like, (5) lubricants, e.g., silicones, fluoropolymers, oleamides, stearamides, erucamides, calcium stearates, or other metal stearates, (6) flame retardants, e.g., ammonium bromide, ammonium hydroxide, aluminum trihydrate, and phosphate esters, (7) cross-linking agents or coupling agents for processing of polypropylene polymers, including polypropylene nucleating agents, and nucleating agents disclosed in U.S. Pat. No. β

In some embodiments, the porous substrate is a single layer porous substrate comprising more than one ply; a two-layer porous substrate, wherein each layer may comprise more than one ply; or a multi-layer porous substrate, wherein each layer may comprise more than one ply. When the porous substrate is a multi-layer porous substrate, it may include 3 to 10 layers, 4 to 9 layers, 5 to 8 layers, or 6 to 7 layers. In some multilayer embodiments, the porous substrate comprises, in order: a polypropylene (PP) layer comprising a majority (greater than 50% of the polymer component) PP; a polyethylene layer (PE) comprising a majority of PE; and another PP layer comprising a majority of the PP. In other embodiments, a multi-layered porous substrate comprises, in order: a PE layer comprising a majority of PEs; a PP layer comprising a majority of PP; and another PE layer comprising a majority of PEs. The layer comprising mostly PP or PE may comprise PP or PE, respectively, in an amount of more than 50% up to 100% of the polymer component.

The porous substrate may be manufactured by any one of a wet manufacturing process, a dry manufacturing process, a particle stretch manufacturing process, and an β -nucleated biaxial orientation (BN-BOPP) manufacturing processSuch as Celgard LL C from Charlotte, N.C. (known as Dry stretch Process)

A dry-stretch process) may be any polyolefin microporous spacer membrane available from Celgard LL C of Charlotte, north carolina alternatively, in other embodiments, the porous substrate may be manufactured by the wet process of korean Celgard Korea, Asahi Kasei, and/or Tonen, which may involve the use of solvents and/or oils, sometimes referred to as a phase separation or extraction process.

Porous substrates herein may most preferably be prepared by a dry-stretch process (also known as the CE L GARD process) and may be MD stretched, TD stretched or MD and TD stretched (with or without relaxation) (sequential and/or simultaneous biaxial stretching), dry-stretch process refers to a process in which pore formation is produced by stretching of a nonporous precursor, see, Kesting, r., Synthetic Polymeric Membranes, a structural perspective, second edition, John Wiley & ns, New York, (NY), (1985), this page 290, as incorporated on the page, as a reference, a woven fibrous material, a fibrous material.

In one embodiment, the porous material may be a dry-stretched porous substrate having: 1) substantially slit, trapezoidal or circular shaped voids, and 2) a ratio of longitudinal tensile strength to transverse tensile strength in the range of 0.1 to 20, preferably 0.5 to 10. See FIGS. 1-5 for hole shapes. The circular holes of FIGS. 1 to 3 are different from the slit-shaped holes of FIGS. 4 to 5 and Kestin. Further, the pore shape of the porous substrates of the present invention may be characterized by the aspect ratio of the pores, which is the ratio of length to width. In one embodiment of the porous substrate of the present invention, the circular holes have an aspect ratio of 0.75 to 1.25. This is in contrast to the aspect ratio of slit-shaped apertured dry-stretched films of greater than 5.0. Regarding the ratio of machine direction tensile strength to cross direction tensile strength, in one embodiment of a circular hole, the ratio is 0.5 to 5.0. This ratio is different from the corresponding ratio for slit-shaped aperture membranes larger than 10.0. Tensile strength in the Machine Direction (MD) and Transverse Direction (TD) was measured using an Instron model 4201 according to the procedure of ASTM-882. Further features of the porous substrate of the present invention may be as follows: an average pore diameter of 0.03 to 0.30 micrometers (m); the porosity is within the range of 20-80%; and/or greater than 50, preferably 100, more preferably 250Kg/cm²The transverse direction tensile strength of (a). The foregoing values are exemplary values and are not intended to be limiting and should therefore be considered as merely representative of the porous substrates of the present invention. Pore size was measured using Aquapore, available from ports Materials, Inc. The pore size is expressed in μm.

The porous substrates of the present invention are preferably prepared by a dry-stretch process in which the precursor is sequentially and/or simultaneously MD stretched, TD stretched, biaxially stretched (i.e., stretched in not only the MD direction but also the TD direction), may be slot-die extruded (e.g., T-die), may be annular-die extruded (e.g., blister or parison), may be cast (e.g., β nucleated biaxially oriented polypropylene, BNBOPP), may be particle stretched, may be single or multiple layers or laminates, may be co-extruded, may be laminated, and/or may be used with other materials or layers, etc. the dry-stretch process may also involve or include extrusion that includes small amounts of pore formers, oils, solvents, plasticizers, waxes, oligomers, fillers, or other extrusion aids (e.g., small amounts of solvents, waxes or oils that may burn off in an oven).

Generally, the process for making the above porous substrate comprises the steps of: the nonporous precursor is extruded and then MD, TD, or biaxial stretched.

Optionally, the non-porous precursor may be annealed prior to stretching. In one embodiment, biaxial stretching includes machine direction stretching and transverse direction stretching with simultaneous controlled machine direction relaxation. The longitudinal stretching and the transverse stretching may be simultaneous or sequential. In one embodiment, the longitudinal stretching is followed by transverse stretching with simultaneous longitudinal relaxation. This sequential process will be discussed in more detail below.

Extrusion is generally conventional (by conventional is meant that dry-stretch processes are conventional). The extruder may have a slot die (for flat precursors) or an annular die (for parison precursors). In the latter case, an expanded parison technique (e.g., blow-up ratio (BUR)) may be employed. However, the birefringence of the nonporous precursor does not have to be as high as in conventional dry-stretch methods. For example, in a conventional dry-stretch process for making porous substrates with > 35% porosity from polypropylene resin, the birefringence of the precursor would be > 0.0130; whereas in the process of the present invention the birefringence of the PP precursor can be as low as 0.0100. In another embodiment, a porous substrate made from a polyethylene resin having a porosity of > 35%, the birefringence of the precursor would be > 0.0280; whereas for the process of the present invention, the birefringence of the PE precursor can be as low as 0.0240.

In one embodiment, annealing (optional) may be carried out at a temperature between Tm-80 ℃ and Tm-10 ℃ (where Tm is the melting temperature of the polymer); in another embodiment, at a temperature between Tm-50 ℃ and Tm-15 ℃. Some materials, such as those having high crystallinity after extrusion, e.g., polybutene, may not require annealing.

The longitudinal stretching may be performed as cold stretching or hot stretching or both, and as a single step or multiple steps. In one embodiment, cold stretching may be performed at < Tm-50 ℃, in another embodiment, at < Tm-80 ℃. In one embodiment, the thermal stretching may be performed at < Tm-10 ℃. In one embodiment, the total longitudinal stretch may be in the range of 50-500%, and in another embodiment, in the range of 100-300%. During longitudinal stretching, the precursor may shrink in the transverse direction (conventional). The transverse direction stretching after MD stretching preferably includes simultaneous controlled machine direction relaxation. This means that as the precursor is stretched in the transverse direction, the precursor is simultaneously allowed to shrink (i.e. relax) in the longitudinal direction in a controlled manner. The transverse stretching may be performed as a cold step, as a hot step, or a combination of both. The total cross direction stretch may be in the range of 100 to 1200% in one embodiment, and 200 to 900% in another embodiment. In one embodiment, the controlled longitudinal relaxation can be in the range of 5 to 80%, and in another embodiment, in the range of 15 to 65%. In one embodiment, the transverse stretching may be performed in multiple steps. During the transverse stretching, the precursor may or may not be allowed to shrink in the longitudinal direction. In embodiments of multi-step transverse stretching, the first transverse step may comprise transverse stretching with controlled machine direction relaxation, followed by simultaneous transverse and machine direction stretching, followed by transverse relaxation and no machine direction stretching or relaxation. Optionally, after longitudinal and transverse stretching, the precursor may undergo heat setting, and/or additional MD or TD stretching, and the like.

In some embodiments, the ratio of Machine Direction (MD) tensile strength to Transverse Direction (TD) tensile strength is between 0.5 and 10.0, in some embodiments 0.5 and 7.5, and in some embodiments 0.5 and 5.0. Machine Direction (MD) and Transverse Direction (TD) tensile strengths were measured using an Instron model 4201 according to the procedure of ASTM-882.

In some embodiments, the porous membrane has a puncture strength of 400g/mil or greater. Puncture strength was measured using an Instron model 4442 based on ASTM D3763. The measurement is made across the width of a microporous membrane (e.g., a porous substrate or membrane), and the puncture strength is defined as the force required to puncture the test sample.

(2) Coating layer

In one aspect, the coating may be the outermost coating of the separator, for example, it may have no other distinct coating formed thereon, or the coating may have at least one other distinct coating formed thereon. For example, in some embodiments, a different polymeric coating may be applied over the coating formed on at least one surface of the porous substrate. In some embodiments, the different polymeric coatings may comprise, consist of, or consist essentially of: at least one of polyvinylidene fluoride (PVdF) or Polycarbonate (PC).

In some embodiments, the coating is applied over one or more additional coatings that have been applied on at least one side of the porous substrate. For example, in some embodiments, the layers that have been applied to the porous substrate are thin, very thin, or ultra-thin layers of at least one of an inorganic material, an organic material, a conductive material, a semi-conductive material, a non-conductive material, a reactive material, or mixtures thereof. In some embodiments, these layers are metal-containing or metal oxide-containing layers. In some preferred embodiments, a metal-containing layer and a metal-containing oxide layer, e.g., a metal oxide of a metal for the metal-containing layer, are formed on a porous substrate prior to forming a coating layer comprising the coating composition described herein. Sometimes, the total thickness of these applied layer or layers is less than 5 microns, sometimes less than 4 microns, sometimes less than 3 microns, sometimes less than 2 microns, sometimes less than 1 micron, sometimes less than 0.5 microns, sometimes less than 0.1 microns, sometimes less than 0.05 microns.

In some embodiments, the thickness of the coating layer formed from the above-described coating composition 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 is less than 4 μm, less than 2 μm, or less than 1 μm.

The coating method is not limited, and the coatings described herein can be applied to a porous substrate, such as described herein, by at least one of the following coating methods: extrusion coating, roll coating, gravure coating, printing, knife coating, air knife coating, spray coating, dip coating, or curtain coating. The coating process may be carried out at room temperature or at elevated temperature.

The coating layer may be any one of non-porous, nanoporous, microporous, mesoporous, or macroporous. The JIS Gurley of the coating layer may be 10,000 or less, 1,000 or less, 700 or less, 600 or less, 500 or less, 400 or less, 300 or less, 200 or less, or 100 or less. For a non-porous coating, JIS Gurley may be 800 or more, 1,000 or more, 5,000 or more, or 10,000 or more (i.e., "infinite Gurley"). For a non-porous coating, while the coating is non-porous when dry, it is a good ionic conductor, especially when it becomes wet with electrolyte.

In some embodiments, the coating may be a one-molecule thick monolayer in which the molecules are at least one of (i) a matrix material or a polymeric binder, (ii) heat-resistant particles, or (iii) selected from the group consisting of a cross-linking agent, a low temperature shutdown agent, a binder, and a thickener.

In some embodiments, the coating is a continuous coating that covers 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 100% of the surface of the porous membrane on at least one side.

In some embodiments, the coating is a discontinuous coating that covers more than 1%, more than 5%, more than 10%, more than 20%, more than 30%, more than 40%, more than 50%, more than 60%, more than 70%, more than 80%, or more than 90% of the surface of the porous membrane on at least one side.

In some preferred embodiments, the coating blocks or prevents dendrite growth or short circuits caused by dendrites. In some embodiments, this may mean that the coating is tortuous or free of pinholes. In other words, the coating does not have any pores with a tortuosity of 1. In some embodiments, the tortuosity is greater than 1, greater than 1.1, greater than 1.2, greater than 1.3, greater than 1.4, greater than 1.5, greater than 1.6, greater than 1.7, greater than 1.8, greater than 1.9, or greater than 2.0.

Composite body, vehicle or device

A composite, jelly roll, flat, or system comprising any of the separators described above and one or more electrodes, such as a negative electrode, a positive electrode, or a negative and positive electrode, disposed in direct contact therewith. The type of electrode is not limited. For example, the electrode may be those suitable for a lithium ion secondary battery.

A lithium ion battery according to some embodiments herein is shown in fig. 7.

Fig. 14 illustrates a cross-sectional view of a lithium pillar battery according to some embodiments herein.

In fig. 14, a lithium ion or lithium metal cylindrical battery 10 includes, for example, a lithium metal or alloy negative electrode 12, a positive electrode 14, and a separator 16 disposed between the negative electrode 12 and the positive electrode 14, all enclosed within a can 20. The illustrated battery cell 10 is a cylindrical battery cell or a "jelly-roll" battery cell, but the present invention is not limited thereto. Other configurations are also included, such as prismatic cells, button cells, pouch cells, stacked cells, or polymer cells. The battery cell may be a primary (single use) or secondary (rechargeable) battery cell or battery. In addition, the electrolyte is not shown. The electrolyte may be a liquid (organic or inorganic) or a gel (or polymer). For convenience, the present invention will be described with respect to a cylindrical battery cell having a liquid organic electrolyte, but the present invention is not so limited and may find use in other battery cell types (e.g., energy storage systems, assembled battery cells, and capacitors) and configurations.

Suitable negative electrodes 12 may be any negative electrode, and may have an energy capacity greater than or equal to, preferably 372mAh/g, preferably 700mAh/g, and most preferably 1000mAh/g in at least one embodiment. The negative electrode may be composed of a lithium metal foil or lithium alloy foil (e.g., lithium aluminum alloy) or a mixture of lithium metal and/or lithium alloy and a material such as carbon (e.g., coke, graphite), nickel, copper, and the like. The negative electrode is preferably not made solely of a lithium-containing intercalation compound or a lithium-containing intercalation compound in at least one embodiment.

Suitable positive electrode 14 can be any positive electrode compatible with the negative electrode, and in at least one embodiment can include an intercalation compoundAn intercalation compound or an electrochemically active polymer. Suitable embedding materials include, for example, MoS₂、FeS₂、MnO₂、TiS₂、NbSe₃、LiCoO₂、LiNiO₂、LiMn₂O₄、V₆O_l3、V₂O₅And CuCl₂. Suitable polymers include, for example, polyacetylene, polypyrrole, polyaniline, and polythiophene.

The electrolyte may be a liquid (organic or inorganic) or a gel (or polymer). generally, the electrolyte preferably consists essentially of a salt and a medium (e.g., in a liquid electrolyte, the medium may be referred to as a solvent; in a gel electrolyte, the medium may be a polymer matrix)₆、LiAsF₆、LiCF₃SO₃、LiN(CF₃SO₃)₃、LiBF₆And L iClO₄A BETTE electrolyte (commercially available from 3M company of Minneapolis, mn), and combinations thereof. The solvent may include, for example, Ethylene Carbonate (EC), Propylene Carbonate (PC), EC/PC, 2-MeTHF (2-methyltetrahydrofuran)/EC/PC, EC/DMC (dimethyl carbonate), EC/DME (dimethylethane), EC/DEC (diethyl carbonate), EC/EMC (ethyl methyl carbonate), EC/EMC/DMC/DEC/PE, PC/DME, and DME/PC. The polymer matrix may include, for example, PVDF (polyvinylidene fluoride), PVDF: THF (PVDF: tetrahydrofuran), PVDF: CTFE (PVDF: chlorotrifluoroethylene), PVDF: HFP (PVDF: hexafluoropropylene), PAN (polyacrylonitrile), and PEO (polyethylene oxide).

Any of the separators, battery cells, or batteries described above may be incorporated into any vehicle (e.g., an electric vehicle) or device (e.g., a cell phone or laptop computer) that is fully or partially powered by a battery.

Various embodiments of the present invention have been described to achieve various objects of the present invention. It is to be understood that these embodiments are merely illustrative of the principles of the invention. Many modifications and adaptations may be apparent to those skilled in the art without departing from the spirit and scope of the present invention.

Examples

(1) At least the following coating compositions are contemplated.

TABLE 1

CJ-heat resistant particles comprising a binder derived from a lactam polymer, optionally with water, an aqueous solvent or a non-aqueous solvent as a solvent.

CM-heat resistant particles and a PVA binder, optionally with water, an aqueous solvent or a non-aqueous solvent as a solvent.

CS-heat resistant particles with acrylic binder, optionally with water, aqueous solvent or non-aqueous solvent as solvent.

a-any crosslinking agent described herein

b-any of the low temperature shutoff agents described herein

c-any of the adhesives described herein

d-any of the thickeners described herein

e-any friction reducer described herein

f-any of the high temperature shutdown agents described herein

(2) Exemplary improved shutdown implementation

As described above, the addition of a low temperature shutdown agent and/or a high temperature shutdown agent may extend the shutdown window of a coated separator compared to an uncoated counterpart or a coated counterpart of the separator, wherein the coating does not include the low temperature shutdown agent and/or the high temperature shutdown agent.

(a) In one exemplary embodiment, coated battery separators according to some embodiments described herein were prepared (inventive examples). The coating composition comprises CJ and polyethylene beads as a low temperature shut-off agent (b), and is coated on a three-layer porous substrate comprising a polypropylene (PP) layer, a Polyethylene (PE) layer and a polypropylene (PP) layer. The shutdown characteristics of the coated battery separator were evaluated according to the resistance test described herein and compared to the shutdown characteristics of the tri-layer porous substrate itself (i.e., the uncoated comparative example). The results are shown in FIG. 8. Fig. 8 shows that the shutdown window for the comparative example is from about 125 c to about 175 c. The lower endpoint of the shut-off window moves from about 125 ℃ to about 95 ℃, i.e., about 30 ℃, when the coating is applied. The upper end points of the shutdown windows of the inventive example and the comparative example are approximately the same. Thus, overall, the shutdown window of the inventive examples was extended by almost 30 ℃, resulting in a safer battery separator.

(b) In another exemplary embodiment, a coated separator (inventive example) is prepared, the coating of which comprises CJ and PVDF as the high temperature shutdown agent (f). The porous substrate of this example is the same as that described in example 2(a) above. The shutdown windows of the coated separators (inventive examples) were evaluated according to the resistance test described herein and compared to uncoated three-layer porous substrates or separators (comparative examples). The results are shown in FIG. 9. In this embodiment, the shutdown window of the inventive examples is reduced by about 5 ℃ and the upper endpoint of the shutdown window extends to > 180 ℃, e.g., greater than 10,000W Ω -cm is obtained at temperatures > 180 ℃²This results in a very safe battery.

(c) In another exemplary embodiment, two coated separators are prepared by coating a multi-layered (tri-layered) porous substrate comprising PP-PE-PP and PE-PP-PE on one side of the porous substrate with a coating comprising CJ and polyvinylpyrrolidone (PVP), e.g., a high temperature shutdown agent. The coating was 3 microns thick. These are embodiments of the present invention. The shutdown windows of these coated separators (the inventive example shown in fig. 10B) were evaluated according to the resistance test described herein and compared to uncoated multi-layer (tri-layer) porous substrates comprising PP-PE-PP and PE-PP-PE (comparative examples shown in fig. 10A and 10C), respectively. Extended shutdown characteristics in excess of 190 ℃ were observed for one-side coated PP-PE-PP porous substrates and one-side coated PE-PP-PE substrates.

(3) Exemplary improved shrinkage embodiments

(a) The addition of at least a thickener and/or a crosslinker to the coating compositions described herein reduces shrinkage, including shrinkage at elevated temperatures, of separators comprising coatings made from these coating compositions. In table 2 below, coating compositions comprising only CS, CS and d (thickeners) and CS, d and a (crosslinkers) were prepared. In these compositions, CS and the thickener are the same in these compositions. CS and thickener shrinkage are measured in the Machine Direction (MD) and Transverse Direction (TD) and are expressed as% MD shrinkage and% TD shrinkage. For the "l 80 ℃ 10 minutes" test, the sample was placed in an oven at l80 ℃ for 10 minutes and then tested as described above for the "150 ℃ 1 hour" test. For the "l 80 ℃ 20 minutes" test, the sample was placed in an oven at 180 ℃ for 20 minutes and then tested as described above for the "150 ℃ 1 hour" test. Shrinkage can be measured for one-side coated porous substrates or two-side coated porous substrates.

Thickness is measured in micrometers using an Emveco Microgag 210-A micrometer thickness gauge and test procedure ASTM D374.

TABLE 2

(4) Exemplary improved coating-electrode adhesion embodiments

As described above, the addition of a binder to the coating compositions described herein increases the adhesion of the coating to an electrode, such as a negative electrode.

(a) Inventive examples were prepared identical to those prepared in section 2(b) above. The coating of this example was evaluated for adhesion to the negative electrode as described herein. The results are shown in FIG. 11. Fig. 11 shows that much of the electrode material, i.e., electrode material from the negative electrode, was transferred onto the separator, indicating good adhesion between the coating and the negative electrode.

(5) Exemplary embodiments for improved coating-porous substrate bond strength

As described above, the addition of a binder to the coating compositions described herein increases the adhesion of the coating to the porous substrate without pretreating the porous substrate.

(6) Exemplary improved Pin removal force embodiments

As described above, for example, the addition of a friction reducer to the coating compositions described herein can improve the pin removal force of the coating (and separators comprising such a coating).

The inventive examples of section 2(c) above (inventive examples, i.e. one side coated PP-PE-PP porous substrate and one side coated PE-PP-PE porous substrate) were compared with uncoated PP-PE-PP porous substrate (control). The pin removal test described herein was performed three times to collect three data points, and the data is reported in table 3 below.

TABLE 3

7) Exemplary improved thermal tip test embodiments

As described above, the separators disclosed herein have improved thermal stability, for example, as demonstrated by the desired behavior in hot tip pore expansion studies. The hot tip test measures the dimensional stability of the separator under spot heating conditions. The test involves contacting the separator with a hot iron tip and measuring the resulting holes. Smaller holes are more desirable.

(a) The thermal tip test was performed on the embodiment of section 2(c) above and the results are reported in table 4 below and fig. 12. It was found that one-side coated PE-PP-PE and PP-PE-PP substrates (inventive examples) performed better (smaller pores) than the uncoated control (uncoated PP-PE-PP porous substrate (control)).

TABLE 4

	Control	One-side coated PE-PP-PE porous substrate	One-side coated PP-PE-PP porous substrate
				Experiment 1:	0.681	0.683
experiment 2:		0.657	0.644
				experiment 3:	0.565	0.688
mean value (mm)	3.669	0.634	0.672

The selected alumina coating on the separator may be fabricated by a Physical Vapor Deposition (PVD) process. The major advantages of PVD processes over other conventional coating techniques include the following:

roll-to-roll manufacturing; can be manufactured in more than one hundred meters per minute;

homogeneous, uniform coating, complete coverage;

no binder coating, less/no defect;

the thickness is adjustable, from a few nanometers to a few micrometers thick.

Referring to fig. 13, there is shown an example of a separator 20 of the present invention the separator 20 preferably comprises at least one ceramic composite layer or coating 22 and at least one polymeric microporous layer 24. preferably a ceramic composite layer and may be adapted to at least prevent shrinkage, oxidation, electronic shorting (e.g., direct or physical contact of the negative and positive electrodes) and/or block dendritic growth. the polymeric microporous layer may be and is preferably adapted to at least prevent direct or physical contact of the negative and positive electrodes under normal conditions, supporting desired battery performance, and/or block (or shut off) ionic conductivity between the negative and positive electrodes at high temperatures to prevent or block thermal runaway.under typical battery or battery operating conditions, the ceramic composite layer 22 of the separator 20 must have sufficient ionic conductivity to allow ionic flow between the negative and positive electrodes so that the battery can produce the desired amount of current.22 and 24 should adhere well to each other, i.e., no unintended separation should occur. layers 22 and 24 may be laminated, coextruded, deposited (e., PVD, CYD or a L D) or a coating process to form a discrete layer 22, preferably having a total thickness in the range of 0.001 to 50 microns, preferably 0 to 5 microns, preferably 0 to 12 microns, preferably 0 to 5 microns, and more preferably 0 to 5 microns.

The ceramic composite layer 22 includes a matrix material or binder 26 having particles 28, such as inorganic or ceramic particles, dispersed therein. The ceramic composite layer 22 is porous or non-porous (it should be understood that some matrix or binder materials swell and gel in the electrolyte and can conduct ions even if the dry separator has a high Gurley (even at 1,000 or at 10,000 Gurley) before being wetted or wetted with electrolyte), and the ionic conductivity of the layer 22 depends primarily on the choice of porosity, electrolyte, matrix material 26, and particles 28. The matrix material 26 or particles 28 of the layer 22 may each be a component of a separator that prevents electronic shorting, in part, by preventing dendrite growth and by keeping the electrodes spaced apart at high temperatures. In addition, the matrix material 26 may also be used as a gel-like electrolyte or a polymer electrolyte (for example, carrying an electrolyte salt). The matrix material 26 preferably comprises about 0.5 wt% to 95 wt%, preferably 5 wt% to 80 wt%, of the ceramic composite layer 22, and the inorganic particles 28 preferably comprise about 5 wt% to 95.5 wt%, preferably 20 wt% to 95 wt%, of the layer 22. Preferably, the composite layer 22 includes 10 wt% to 99 wt%, preferably 30 wt% to 75 wt% inorganic particles. Most preferably, the composite layer 22 comprises 20 wt% to 98 wt%, preferably 40 wt% to 60 wt% inorganic particles.

The matrix material 26 may include organic and/or inorganic particles, and in addition, may include electrolyte particles or materials and/or may function as a gel-like electrolyte or polymer electrolyte (e.g., supporting electrolyte salts) and/or as a binder (may adhere to the electrodes, may reduce gaps or spaces between the separator and the electrodes, may provide uniform charge distribution, and/or may prevent dendrite formation). The matrix material or binder 26 may preferably constitute about 0.5 wt% to 95 wt%, preferably 2 wt% to 80 wt%, of the ceramic composite layer 22, and the particles 28 preferably constitute about 5 wt% to 95.5 wt%, preferably 20 wt% to 98 wt%, of the layer 22. In a particular embodiment, the particles are coated particles with a binder material as a coating. In another particular embodiment, the particles are a mixture of two or more particle types or sizes.

The matrix material 26 may be ionically conductive or non-conductive, for example, a solvent or aqueous polymer or binder, such as PVDF, acrylic, polyamide, and/or any polymer, copolymer thereof, and combinations, copolymers, blends, or mixtures thereof, suggested for use in gel-forming lithium polymer batteries or solid electrolyte batteries. The matrix material 26 may be selected from, for example, polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE), polyurethane, Polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polytetraethylene glycol diacrylate, copolymers thereof, and mixtures thereof. Preferred matrix materials are PVDF and/or PEO and their copolymers. PVDF copolymers include PVDF: HFP (polyvinylidene fluoride: hexafluoropropylene) and PVDF: CTFE (polyvinylidene fluoride: chlorotrifluoroethylene). The most preferred matrix materials include PVDF: CTFE wherein CTFE is less than 23 wt%, PVDF having less than 28 wt% HFP, PEO of any type, and combinations, blends, mixtures or copolymers thereof. In a particular embodiment, the binder may be a polyimide or polyamide, for example a solvent soluble polyimide or polyamide.

The inorganic particles 28 are generally considered to be electrically non-conductive, however, when these particles come into contact with the electrolyte, an ionically conductive or superconducting surface is formed, which improves the ionic conductivity (reduces the electrical resistance) of the separator 20. The inorganic particles 28 may be selected from, for example, Silica (SiO)₂) Alumina (Al)₂O₃) Boehmite, kaolin, clay, barium sulfate, calcium carbonate (CaCO)₃) Titanium dioxide (TiO)₂)、SiS₂、SiPO₄An X-ray detectable material, kaolin, calcined clay, kaolinite, metastable alumina, or a combination, blend, or mixture thereof. Preferred inorganic particles may be boehmite, kaolin, SiO₂、Al₂O₃Barium sulfate and/or CaCO₃. The average particle size of the particles may be in the range of from 0.001 microns to 25 microns, preferably in the range of from 0.01 microns to 2 microns, most preferably in the range of from 0.05 microns to 0.5 microns.

The microporous polymer layer 24 may be any of several types of microporous films (e.g., single or multiple layers), sheets, films, or layers, such as C from Charlotte, N.C.Those produced by elgard, LL C

Microporous polyolefin product, or produced by Asahi Kasei Corp of Tokyo, Japan

Microporous polyolefin products, and the like. The porosity of the layer 24 may be in the range of 10 to 90%, preferably in the range of 20 to 80%, and more preferably in the range of 28 to 60%. The average pore size of the layer 24 may be in the range of 0.001 to 2 microns, preferably in the range of 0.02 to 2 microns, preferably in the range of 0.05 to 1 micron, more preferably in the range of 0.08 to 0.5 microns. The Gurley number of the layer 24 may be preferably in the range of 5 to 150 seconds, preferably in the range of 15 to 150 seconds, preferably in the range of 10 to 80 seconds, and more preferably in the range of 30 to 60 seconds. (Gurley number refers to the time it takes 10cc of air to pass through a1 square inch membrane in 12.2 inches of water.) layer 24 is preferably a polyolefin. Preferred polyolefins include polyethylene and polypropylene, or combinations, blends, copolymers, block copolymers or mixtures thereof.

In accordance with at least certain selected embodiments, the present invention or application relates to or provides new or improved coatings for porous substrates, including battery separators, capacitor separators, fuel cell membranes, textile materials, apparel materials or layers, and filter materials, and the like, as well as new and/or improved coated porous substrates, including battery separators, and more particularly, to new or improved coatings for porous substrates, including battery separators, capacitor separators, fuel cell separators, textile materials, apparel materials or layers, and filter materials, and the like, comprising at least (i) a polymeric binder, (ii) optionally organic and/or inorganic pressure, dendrite and/or heat resistant particles, and (iii) a coating selected from the group consisting of cross-linkers, shutdown agents, low temperature shutdown agents, high temperature shutdown agents, adhesives, X-ray detectable elements, metal oxides, and metal oxides, At least one component of the group consisting of friction reducers and/or thickeners, and/or new and/or improved coated porous substrates, including battery separators, wherein the coating comprises at least (i) a polymeric binder, (ii) optionally organic and/or inorganic pressure-, dendrite-and/or heat-resistant particles, and (iii) at least one component selected from the group consisting of cross-linkers, shutdown agents, low temperature shutdown agents, high temperature shutdown agents, binders, X-ray detectable elements, friction reducers and/or thickeners.

In accordance with at least certain objects, aspects or embodiments, certain new and/or improved coatings for porous substrates, including battery separators or separator membranes, and/or coated porous substrates, including coated battery separators, and/or batteries or cells including such coatings or coated separators, and/or related methods including methods of making and/or using the same, are described or shown. Further, new or improved coatings for porous substrates, including battery separators, comprising at least a matrix material or a polymeric binder, and heat-resistant particles and additional additives, materials, or components, and/or to new or improved coated porous substrates, including battery separators, wherein a coating comprises at least a matrix material or a polymeric binder, and heat-resistant particles and additional additives, materials, or components, are disclosed. In addition, new or improved coatings for porous substrates, including battery separators, and new and/or improved coated porous substrates, including battery separators, new or improved coatings for porous substrates, the substrate comprises a battery separator, the coating comprising at least (i) a matrix material or a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a crosslinking agent, a low temperature shutdown agent, a binder, and a thickener, and new and/or improved coated porous substrates including battery separators, wherein the coating comprises at least (i) a matrix material or a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a crosslinking agent, a low temperature shutdown agent, a binder, a thickener, a friction reducer, a high temperature shutdown agent. The polymer matrix or binder may include, for example, PVDF (polyvinylidene fluoride), PVDF: THF (PVDF: tetrahydrofuran), PVDF: CTFE (PVDF: chlorotrifluoroethylene), PVDF: HFP (PVDF: hexafluoropropylene), PAN (polyacrylonitrile), PVA (polyvinyl alcohol), PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxy), fluoropolymers, acrylic acid, PO (polyolefin), PE (polyethylene), PP (polypropylene), PMP (polymethylpentene), PEO (polyethylene oxide), polyacrylic acid (PAA), Polymethylmethacrylate (PMMA), Polyacrylonitrile (PAN), Polymethylmethacrylate (PMA), and composites, combinations, mixtures, blends, copolymers, or block copolymers thereof.

In other preferred embodiments, the polymeric binder comprises, consists of, or consists essentially of: carboxymethyl cellulose (CMC), isobutylene polymers, latex.

Certain new and/or improved methods are described or shown in accordance with at least certain objects, aspects or embodiments. For example, a method for detecting the position of a separator relative to an electrode in a secondary lithium battery includes the steps of: providing a secondary lithium battery comprising a positive electrode, a negative electrode, an X-ray sensitive separator positioned between the electrodes, the X-ray sensitive separator comprising a microporous membrane having an X-ray detectable element dispersed therein or thereon, the X-ray detectable element comprising at least 1% and no greater than 80% by weight of the membrane, and a can or pouch containing the electrodes and separator; performing X-ray irradiation on a secondary lithium battery; determining a position of the separator relative to the electrode; and approving or rejecting the secondary lithium battery based on the position of the separator relative to the electrode.

The method wherein the X-ray detectable element comprises from 2% to 70% by weight of the film.

The method wherein the X-ray detectable element comprises from 5% to 50% by weight of the film.

The above method, wherein the X-ray detectable element is included in a coating on the film.

The above method, wherein the X-ray detectable element is selected from the group consisting of a metal, a metal oxide, a metal phosphate, a metal carbonate, an X-ray fluorescent material, a metal salt, a metal sulfate, or a mixture thereof, and any of the foregoing metals is selected from the group consisting of Zn, Ti, Mn, Ba, Ni, W, Hg, Si, Cs, Sr, Ca, Rb, Ta, Zr, Al, Pb, Sn, Sb, Cu, Fe, and a mixture thereof.

The method wherein the X-ray detectable element is preferably barium sulfate.

The above method, wherein the X-ray detectable element is in a coating on at least one side of the film.

The above method, wherein the coating is a ceramic coating.

The above method, wherein the X-ray detectable element is at least one of dispersed therein, coated thereon, or added thereto.

The new and/or improved separators described herein may have or exhibit one or more of the following characteristics or improvements (1) a desired porosity level observed and measured by SEM, (2) a desired Gurley number showing permeability, (3) a desired thickness, (4) a desired level of coalescence of a polymeric binder to improve the coating relative to a known coating, such as a chemical vapor deposition or physical vapor deposition of CCDS or CCDS of CCDS or of CCDS-phase-coated or PCS-coated CCDS-coated or PCS-coated CCCS (PCS) onto a PCS-coated or PCS coated PCS-coated or PCS-coated PCS-coated ceramic-coated or ceramic-coated PCS-coated or ceramic-coated PCS-coated lithium battery (PCS) and/PCS-coated-electrode-coated lithium-coated-electrode-coated-electrode-coated-electrode-coated electrode-coated electrode-coated electrode-coated electrode-coated electrode-coated electrode-battery-electrode-battery-electrode-battery-electrode-.

In accordance with various aspects, objects, or embodiments, new and/or improved coatings, layers, or treatments for porous substrates, including battery separators or separator membranes, and/or coated or treated porous substrates, including coated battery separators, and/or batteries or cells including such coatings or coated separators, and/or related methods including methods of making and/or using the same, are described or provided. Additionally, new or improved coatings for porous substrates, including battery separators, comprising at least a matrix material or polymeric binder and heat-resistant particles and additional additives, materials, or components, and/or new or improved coated or treated porous substrates, including battery separators, wherein the coatings comprise at least a matrix material or polymeric binder and heat-resistant particles and additional additives, materials, or components, are disclosed. Further, disclosed are new or improved coatings for porous substrates, including battery separators, and new and/or improved coated porous substrates, including battery separators, new or improved coatings for porous substrates, the substrate comprises a battery separator, the coating comprising at least (i) a matrix material or a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a crosslinking agent, a low temperature shutdown agent, a binder, and a thickener, and new and/or improved coated porous substrates, including battery separators, wherein the coating comprises at least (i) a matrix material or a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a crosslinking agent, a low temperature shutdown agent, a binder, a thickener, a friction reducer, and a high temperature shutdown agent.

Various embodiments of the present invention have been described to achieve various objects of the present invention. It is to be understood that these embodiments are merely illustrative of the principles of the invention. Many modifications and adaptations thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A separator for a high energy rechargeable lithium battery, comprising:

at least one ceramic composite layer or coating, said layer being formed from a coating composition comprising a matrix material or polymeric binder, heat-resistant particles, and a crosslinking agent; the layer is adapted for at least one of:

blocking dendrite growth and preventing electronic shorting;

blocking dendrite growth after repeated charge-discharge cycles throughout the life of the rechargeable battery;

preventing electronic short circuits throughout repeated charge-discharge cycles throughout the life of the rechargeable battery;

blocking dendrite growth after repeated charge-discharge cycles;

preventing electronic short circuits;

blocking dendrite growth and thereby preventing electronic shorting after repeated charge-discharge cycles;

preventing an electronic short circuit by preventing direct contact between a negative electrode and a positive electrode of a high energy rechargeable battery;

preventing an electronic short circuit by preventing direct contact between the negative electrode and the positive electrode throughout repeated charge-discharge cycles;

preventing electronic shorting by preventing direct contact between the negative and positive electrodes throughout the cycle life of the battery;

preventing electronic shorts by eliminating hard shorts caused by dendrites;

preventing electronic short circuits by eliminating soft short circuits caused by dendrites;

preventing electronic shorts by eliminating hard shorts caused by dendrites growing during repeated charge-discharge cycles;

preventing electronic short circuits by eliminating soft short circuits caused by dendrites growing during repeated charge-discharge cycles;

preventing electronic shorts by eliminating hard shorts caused by dendrites throughout the commercial life of the battery;

preventing electrical shorts by eliminating soft shorts caused by dendrites throughout the commercial life of the battery; and/or

Is adapted to prevent short-circuiting of other electrons,

and at least one polyolefin microporous layer, said layer being adapted for at least one of:

blocking ion flow between the negative and positive electrodes of the battery; and/or

The flow of ions between the negative and positive electrodes of the battery is turned off and blocked.

2. The separator of claim 1, the ceramic composite layer comprising, having, being, or exhibiting at least one of:

the thickness is 0.01 to 25 microns;

comprises heat-resistant particles with the average particle size of 0.001-24 microns;

is non-porous so that pores are formed upon contact with the electrolyte;

further comprising another distinct coating layer formed thereon;

comprises 20 to 95 weight percent of SiO₂、Al₂O₃、CaCO₃、TiO₂、SiS₂And SiPO₄And the like, and mixtures thereof, 5 to 80 weight percent of a matrix material or a polymeric binder selected from the group consisting of polyethylene oxide, polyvinylidene fluoride, polytetrafluoroethylene, copolymers of the foregoing, and mixtures thereof, and a cross-linking agent;

coating composition comprising heat resistant particles having an average particle size in the range of 0.001 to 24 micrometers and a crosslinker in a matrix material or polymeric binder, wherein the heat resistant particles comprise dioxygenSilicon (SiO)₂) Alumina (Al)₂O₃) Calcium carbonate (CaCO)₃) Titanium dioxide (TiO)₂)、SiS₂、SiPO₄Or mixtures thereof;

a coating composition comprising about 20 to 95 weight percent of heat resistant particles, about 5 to 80 weight percent of a matrix material or polymeric binder, and a crosslinking agent.

A coating composition comprising heat resistant particles having an average particle size in the range of 0.001-24 microns and a crosslinker in a matrix material or polymeric binder, the matrix material comprising polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE), polyurethane, Polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polytetraethylene glycol diacrylate, copolymers thereof, or mixtures thereof, wherein the heat resistant particles comprise Silica (SiO)₂) Alumina (Al)₂O₃) Calcium carbonate (CaCO)₃) Titanium dioxide (TiO)₂)、SiS₂、SiPO₄Or mixtures thereof;

a coating composition comprising heat resistant particles having an average particle size in the range of 0.001 to 24 microns and a crosslinker in a matrix material or polymer binder, wherein the matrix material comprises PVDF (polyvinylidene fluoride), PAN (polyacrylonitrile), PEO (polyethylene oxide), or copolymers or mixtures thereof; and/or

A coating composition comprising heat resistant particles having an average particle size in the range of 0.001 to 24 microns and a crosslinking agent in a matrix material or a polymeric binder.

3. The separator of claim 1, wherein the polyolefin microporous layer has or comprises at least one of:

a porosity of about 20-80%;

the average pore diameter is within the range of 0.02-2 microns;

the Gurley number is within the range of 15-150 seconds; and/or

Comprising at least one of polyethylene, polypropylene, and mixtures thereof.

4. The separator of claim 1, wherein the heat resistant particles are selected from the group consisting of:

SiO₂；

A1₂O₃；

CaCO₃；

TiO₂；

SiS₂；

SiPO₄；

an organic material or a mixture of organic materials, and the organic material is at least one of a polyimide resin, a melamine resin, a polymethyl methacrylate (PMMA) resin, a polystyrene resin, a polyvinyl benzene (PDVB) resin, carbon black, and graphite; and/or

Mixtures thereof.

5. The separator of claim 1, wherein the base material is or comprises:

selected from the group consisting of polyethylene oxide, polyvinylidene fluoride, polytetrafluoroethylene, polyurethane, polyacrylonitrile, polymethyl methacrylate, polytetraethylene glycol diacrylate, copolymers thereof, or mixtures thereof;

a continuous material in which the heat-resistant particles are embedded;

comprising polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE), Polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polytetraethylene glycol diacrylate, copolymers thereof, or mixtures thereof, PVDF and/or PEO and copolymers thereof, PVDF: HFP (polyvinylidene fluoride: hexafluoropropylene), PVDF: CTFE (polyvinylidene fluoride: chlorotrifluoroethylene), PVDF having less than 23 wt.% CTFE, PVDF having less than 28 wt.% HFP, or mixtures thereof;

comprises polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE), polyurethane, Polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polytetraethylene glycol diacrylate, copolymers thereof, or mixtures thereof;

comprising polyvinylidene fluoride (PVDF), polyethylene oxide (PEO), copolymers thereof, or mixtures thereof;

comprising a gel-forming polymer;

comprising PVDF (polyvinylidene fluoride), PEO (polyethylene oxide), or copolymers thereof, or mixtures thereof;

comprising PVDF (polyvinylidene fluoride), or copolymers thereof, or mixtures thereof;

selected from the group consisting of polyethylene oxide, polyvinylidene fluoride, polytetrafluoroethylene, polyacrylonitrile, polymethyl methacrylate, polytetraethylene glycol diacrylate, copolymers thereof, or mixtures thereof;

selected from the group consisting of polyvinylidene fluoride, polytetrafluoroethylene, polyacrylonitrile, polymethyl methacrylate, polytetraethylene glycol diacrylate, copolymers thereof, or mixtures thereof;

comprising polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE), Polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polytetraethylene glycol diacrylate, copolymers thereof, or mixtures thereof, PVDF and/or PEO and copolymers thereof, PVDF: HFP (polyvinylidene fluoride: hexafluoropropylene), PVDF: CTFE (polyvinylidene fluoride: chlorotrifluoroethylene), PVDF having less than 23 wt.% CTFE, PVDF having less than 28 wt.% HFP, or mixtures thereof; and/or

Comprising polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE), Polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polytetraethylene glycol diacrylate, copolymers thereof, or mixtures thereof, PVDF and/or PEO and copolymers thereof, PVDF: HFP (polyvinylidene fluoride: hexafluoropropylene), PVDF: CTFE (polyvinylidene fluoride: chlorotrifluoroethylene), PVDF having less than 23 wt.% CTFE, PVDF having less than 28 wt.% HFP: HFP, or mixtures thereof.

6. The separator of claim 1, wherein the polymeric binder comprises, encompasses, or is at least one of:

containing water, an aqueous solvent, or a nonaqueous solvent as a solvent;

comprises at least one selected from the group consisting of polylactam polymer, polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyvinyl acetate (PVAc), carboxymethylcellulose (CMC), isobutylene polymer, acrylic resin, and latex;

comprising polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyvinyl acetate (PVAc), carboxymethylcellulose (CMC), isobutylene polymers, acrylics, and/or latex;

comprising a polylactam polymer that is a homopolymer, copolymer, block polymer, or block copolymer derived from a lactam;

a polylactam comprising the formula (1):

preferred polylactams among these are homopolymers or copolymers wherein the copolymeric group X is derived from vinyl, substituted or unsubstituted alkylvinyl, vinyl alcohol, vinyl acetate, acrylic acid, alkyl acrylate, acrylonitrile, maleic anhydride, maleimide, styrene, polyvinylpyrrolidone (PVP), polyvinylvalerolactam, polyvinylcaprolactam (PVCap), polyamides, or polyimides; wherein m is an integer of 1 to 10, preferably 2 to 4,

and wherein the ratio of l to n is 0. ltoreq. l: n. ltoreq.10 or 0. ltoreq. l: n. ltoreq.1;

comprising a homopolymer or copolymer derived from a lactam, wherein the homopolymer or copolymer derived from a lactam is at least one selected from the group consisting of polyvinylpyrrolidone (PVP), polyvinylcaprolactam (PVCap), and polyvinylvalerolactam;

comprising a polylactam according to formula (2) and a catalyst:

wherein R is₁、R₂、R₃And R₄Is an alkyl or aromatic substituent;

R₅is alkyl, aryl or a fused ring;

m is an integer of 1 to 10, preferably 2 to 4,

and wherein the ratio of l to n is 0. ltoreq. l: n. ltoreq.10 or 0. ltoreq. l: n. ltoreq.1,

and X is an epoxide or alkylamine;

comprising a polylactam according to formula (2) and a catalyst:

wherein R is₁、R₂、R₃And R₄Is an alkyl or aromatic substituent;

R₅is alkyl, aryl or a fused ring;

m is an integer of 1 to 10, preferably 2 to 4,

x is an epoxide and the catalyst comprises an alkylamine or epoxide;

covering 0.01 to 99.99% of the surface area of at least one of the heat-resistant particles; and/or

Such that the ratio of heat-resistant particles to binder in the coating composition is comprised from 50:50 to 99: 1.

7. A separator as claimed in claim 1, wherein the cross-linking agent is or comprises at least one of:

comprises a plurality of reactive groups;

is an epoxy cross-linker comprising a plurality of reactive epoxy groups;

and/or an acrylate crosslinker having a plurality of reactive acrylate groups.

8. The separator of claim 1, wherein the separator is a shutdown separator.

9. A lithium ion secondary battery comprising the separator according to any one of claims 1 to 8.

10. A composite comprising the separator of any one of claims 1 to 8 in direct contact with an electrode of a lithium ion secondary battery.

11. A vehicle or apparatus comprising the partition of any one of claims 1 to 8.

12. A high energy rechargeable lithium battery, comprising:

negative electrode containing lithium metal or lithium alloy or mixture of lithium metal and/or lithium alloy and other material

A positive electrode;

the separator according to any one of claims 1 to 8, provided between the negative electrode and the positive electrode; and

an electrolyte in ionic communication with the negative electrode and the positive electrode via the separator.

13. A rechargeable lithium battery, comprising:

a negative electrode, wherein the negative electrode comprises lithium metal, a lithium alloy, a lithium intercalation compound, a lithium insertion compound, a carbon intercalation compound, or mixtures thereof;

a positive electrode, wherein the positive electrode comprises an intercalation compound, an electrochemically active polymer, or a mixture thereof;

a separator disposed between the negative electrode and the positive electrode, wherein the separator includes: at least one ceramic composite layer, wherein the ceramic composite layer is a coating having a thickness in the range of about 0.01 to 25 microns and comprises: a coating composition of heat-resistant particles having an average particle diameter in the range of 0.001 to 24 μm in a base material or a polymer binder and a crosslinking agent, wherein the heat-resistant particles comprise Silica (SiO)₂) Alumina (A1)₂O₃) Calcium carbonate (CaCO)₃) Titanium dioxide (TiO)₂)、SiS₂、SiPO₄Or mixtures thereof, and wherein the ceramic composite layer is adapted to at least block dendrite growth after repeated charge-discharge cycles and prevent electronic shorting throughout repeated charge-discharge cycles throughout the cycle life of the rechargeable battery;and at least one polyolefin microporous layer, wherein the polyolefin microporous layer comprises a polyolefin membrane of at least one of polyethylene or polypropylene and is adapted to shut off and block ion flow between the negative electrode and the positive electrode; and

an electrolyte in ionic communication with the anode and the cathode via the separator, wherein the electrolyte comprises a liquid.

14. The battery of claim 13, wherein at least one of:

the negative electrode comprises only a carbon intercalation compound; and/or

The matrix material comprises polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE), Polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polytetraethylene glycol diacrylate, copolymers thereof, or mixtures thereof, PVDF and/or PEO and copolymers thereof, PVDF: HFP (polyvinylidene fluoride: hexafluoropropylene), PVDF: CTFE (polyvinylidene fluoride: chlorotrifluoroethylene), PVDF: CTFE having less than 23 wt.% CTFE, PVDF: HFP having less than 28 wt.% HFP, or mixtures thereof.

15. A rechargeable lithium battery, comprising:

a negative electrode;

a positive electrode;

16. The rechargeable battery of claim 15, wherein at least one of:

the negative electrode comprises lithium metal, a lithium alloy, a lithium intercalation compound, a carbon intercalation compound, or a mixture thereof;

the negative electrode comprises only a carbon intercalation compound;

the energy capacity of the negative electrode is about 372mAh/g or more;

the positive electrode comprises an intercalation compound, or an electrochemically active polymer, or mixtures thereof;

the positive electrode contains MoS₂、FeS₂、MnO₂、TiS₂、NbSe₃、LiCoO₂、LiNiO₂、LiMn₂O₄、V₆O_l3、V₂O₅、CuCl₂Polyacetylene, polypyrrole, polyaniline, or polythiophene or mixtures thereof;

the electrolyte comprises a liquid;

the electrolyte is a liquid organic electrolyte;

the electrolyte comprises a liquid and a polymer;

the electrolyte comprises a salt and a liquid solvent, wherein the salt comprises a salt selected from L iPF₆、LiAsF₆、LiCF₃SO₃、LiN(CF₃SO₃)₃、LiBF₆、LiClO₄Or a mixture thereof, and wherein the liquid solvent comprises Ethylene Carbonate (EC), Propylene Carbonate (PC), EC/PC, 2-MeTHF (2-methyltetrahydrofuran)/EC/PC, EC/DMC (dimethyl carbonate), EC/DME (dimethylethane), EC/DEC (diethyl carbonate), EC/EMC (ethylmethyl carbonate), EC/EMC/DMC/DEC/PE, PC/DME, DME/PC, or a mixture thereof; and/or

The electrolyte comprises a salt, a liquid solvent, and a polymer, wherein the salt comprises a salt selected from L iPF₆、LiAsF₆、LiCF₃SO₃、LiN(CF₃SO₃)₃、LiBF₆、LiClO₄Or a mixture thereof, and wherein the liquid solvent and the polymer comprise PVDF (polyvinylidene fluoride), PVDF: THF (PVDF: tetrahydrofuran), PVDF: CTFE (PVDF: chlorotrifluoroethylene), PAN (polyacrylonitrile), PEO (polyethylene oxide), or a mixture thereof.

17. A rechargeable lithium battery, comprising:

a separator disposed between the negative electrode and the positive electrode, wherein the separator includes: at least one ceramic composite layer and at least one polyolefin microporous layer,

wherein the ceramic composite layer is a coating having a thickness in the range of about 0.001 to 25 microns and comprises: a coating composition of heat-resistant particles having an average particle diameter in the range of 0.001 to 24 μm in a base material or a polymer binder and a crosslinking agent,

the matrix material comprises PEO, PVDF, PTFE, polyurethane, PAN, PMMA, polytetraethylene glycol diacrylate, copolymers thereof or mixtures thereof,

the heat-resistant particles comprise silicon dioxide (SiO)₂) Alumina (A1)₂O₃) Calcium carbonate (CaCO)₃) Titanium dioxide (TiO)₂)、SiS₂、SiPO₄Or a mixture thereof,

the ceramic composite layer is adapted to at least block dendrite growth after repeated charge-discharge cycles and thereby prevent electronic shorting by preventing direct contact between the negative and positive electrodes throughout repeated charge-discharge cycles of the overall cycle life of the rechargeable battery;

and at least one polyolefin microporous layer, wherein the polyolefin microporous layer comprises a shutdown polyolefin membrane of polyethylene or polypropylene and is adapted to block ion flow between the negative electrode and the positive electrode via the separator; and

18. The battery of claim 17, wherein at least one of:

the negative electrode comprises only a carbon intercalation compound;

the energy capacity of the negative electrode is about 372mAh/g or more;

the electrolyte comprises a liquid and a polymer;

19. A rechargeable lithium battery, comprising:

a separator disposed between the negative electrode and the positive electrode, wherein the separator includes: at least one ceramic composite layer, wherein the ceramic composite layer is a coating having a thickness in the range of about 0.01 to 25 microns and comprises: a coating composition of heat resistant particles having an average particle size in the range of 0.001-24 microns and a cross-linking agent in a matrix material or polymer binder, wherein the matrix material comprises PVDF (polyvinylidene fluoride), PAN (polyacrylonitrile), PEO (polyethylene oxide), or copolymers thereof or mixtures thereof, and wherein the ceramic composite layer is adapted to at least block dendrite growth after repeated charge-discharge cycles and prevent electronic shorting through the entire repeated charge-discharge cycles of the entire cycle life of the rechargeable battery; and at least one polyolefin microporous layer, wherein said polyolefin microporous layer comprises a polyolefin membrane of at least one of polyethylene or polypropylene and is adapted to shut off and block ion flow between said negative electrode and said positive electrode; and

20. The battery of claim 19, wherein at least one of:

the heat-resistant particles comprise silicon dioxide (SiO)₂) Alumina (A1)₂O₃) Calcium carbonate (CaCO)₃) Titanium dioxide (TiO)₂)、SiS₂、SiPO₄Or a coating composition thereof;

the negative electrode comprises only a carbon intercalation compound; and/or

The ceramic composite layer prevents an electronic short circuit by preventing direct contact between the anode and the cathode.