EP1183743A1

EP1183743A1 - Composite bodies used as separators in electrochemical cells

Info

Publication number: EP1183743A1
Application number: EP00925182A
Authority: EP
Inventors: Stephan Bauer; Bernd Bronstert; Helmut MÖHWALD
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1999-04-09
Filing date: 2000-04-07
Publication date: 2002-03-06
Also published as: TW488108B; RU2001130341A; KR20010112412A; AU4398900A; US6746803B1; DE19916109A1; CN1355940A; WO2000062355A1; CA2369483A1; JP2002541644A

Abstract

The invention relates to composite bodies having at least one first layer, containing a composition comprising (a) 1 to 99 percent by weight of a solid (I) with a primary particle size ranging from 5 nm to 100 νm or a mixture consisting of at least two solids; (b) 99 to 1 percent by weight of a polymeric binder (II) obtained by polymerization of b1) 5 to 100 percent by weight, in relation to the binder (II), of a condensation product (III) consisting of (α) at least one compound (IV) capable of reacting with a carboxylic acid or a sulphonic acid or a derivative or a mixture of two or more thereof and (β) at least one mole per mole of the compound (IV) consisting of a carboxylic acid or a sulphonic acid (V) having at least one radically polymerizable functional group or a derivative thereof or a mixture consisting of two or more thereof and b2) 0 to 95 percent by weight, in relation to the binder (II), of an additional compound (VII) having a mean molecular weight (numerical average) of at least 5000 with polyether segments in the main or side chain, wherein the at least one layer is applied on at least one second layer comprising at least one conventional separator.

Description

Composite bodies suitable as separators in electrochemical cells

The present invention relates to composite bodies which are particularly suitable as separators for electrochemical cells, preferably rechargeable cells and in particular lithium batteries and lithium ion batteries, these separators or electrochemical cells per se, and a method for producing these composite bodies.

Electrochemical, in particular rechargeable, cells are generally known, for example from “Ullmann's Encyclopedia of Industrial Chemistry”, 5th ed. Vol A3, VCH Verlagsgesellschaft mbH, Weinheim, 1985, pages 343-397.

Among these cells, the lithium batteries and the lithium ion batteries, in particular as secondary cells, occupy a special position due to their high specific energy storage density.

Such cells contain in the cathode, as described, inter alia, in the above quotation from "Ulimann", lithiated manganese, cobalt, vanadium or nickel mixed oxides, such as those in the simplest stoichiometric case as LiMn O ₄ , LiCoO, LiV ₂ O ₅ or LiNiO can be described.

These compounds react reversibly with compounds that can incorporate lithium ions into their lattice, such as graphite, to expand the lithium ions from the crystal lattice, in which the metal ions such as manganese, cobalt or nickel ions are oxidized. This reaction can be used in an electrochemical cell for storing electricity by separating the compound which absorbs lithium ions, that is to say the anode material, and the mixed oxide containing lithium, that is to say the cathode material, by means of an electrolyte which the lithium ions migrate from the mixed oxide into the anode material (charging process).

The compounds suitable for the reversible storage of lithium ions are usually fixed on discharge electrons by means of a binder.

When the cell is charged, electrons flow through an external voltage source and lithium cations through the electrolyte to the anode material. When the cell is used, the lithium cations flow through the electrolyte, while the electrons flow through a useful resistance from the anode material to the cathode material.

To avoid a short circuit within the electrochemical cell, there is an electrically insulating layer that is continuous for lithium cations between the two electrodes. This can be a so-called solid electrolyte or an ordinary separator.

Solid electrolytes and separators are known to consist of a carrier material into which a dissociable compound containing lithium cations to increase the lithium ion conductivity and usually other additives such as solvents are incorporated.

Microporous films have been proposed as separators for some time. For example, GB 2 027 637 describes a microporous film which comprises a matrix with 40 to 90% by volume of a polyolefin, 10 to 60% by volume of an inorganic filler and further constituents, as defined therein in each case. The matrix described therein has 30 to 95 vol .-% vacancies, based on the film volume, and is a separator for lead acid batteries.

A two-layer battery separator with a shutdown characteristic is described in EP-B 0 715 364. The battery separator described there has one a first shutdown microporous membrane made of a material selected from polyethylene, a blend consisting essentially of polyethylene, and a copolymer of polyethylene; it also has a second microporous membrane with a strength function, which is made of a material made of polypropylene, a blend. which essentially comprises polypropylene and is selected from a copolymer of polypropylene. According to the description, this separator has improved mechanical strength and through energy compared to the prior art.

A three-layer battery separator with a shutdown characteristic is described in EP-A 0 718 901. This separator comprises first and third microporous polypropylene membranes, which in turn include a microporous polyethylene membrane, the first and third membranes having greater puncture resistance and a higher melting point than the second membrane.

A composite polymer electrolyte in membrane form, which has an ion-conducting polymer gel applied to a matrix material made of a porous polytetrafluoroethylene membrane, is described in EP-A-0 708 791.

A composite body which is suitable as a separator in electrochemical cells and comprises a conventional, layer-shaped separator and at least one further layer which comprises a solid and a polymeric binder, a polymer or co-polymer which has chain, end and / or laterally reactive groups, which are capable of crosslinking reactions thermally and / or under UV radiation is described in DE-A 198 59 826.3.

In view of this prior art, the primary object of the present invention was to provide a separator which also has a

Shutdown mechanism and also has a form stability at high

Temperature (> 150 ° C) and a further improved mechanical strength and also has excellent ion-conducting properties, or represents an alternative system to the composite body according to DE-A 198 50 826.3.

The present invention thus relates to a composite body comprising a composite body comprising at least one first layer which comprises a composition

(a) 1 to 99% by weight of a solid (I) with a primary particle size of 5 nm to 100 μm or a mixture of at least two solids,

(b) 99 to 1% by weight of a polymeric binder (II), obtainable by polymerizing

bl) 5 to 100 wt .-% based on the binder (II)

Condensation product III from α) at least one compound TV which is capable of reacting with a carboxylic acid or a sulfonic acid or a derivative or a mixture of two or more thereof, and

β) at least 1 mole per mole of compound IV of a carboxylic acid or sulfonic acid V which has at least one free-radically polymerizable functional group, or a derivative thereof or a mixture of two or more thereof and

b2) 0 to 95% by weight, based on the binder (II), of a further compound VII with an average molecular weight (number average) of at least 5,000 with polyether segments in the main or side chain, the at least one first layer comprising at least a second layer comprising at least one conventional separator is applied. The present invention further relates to a composite body of the type mentioned above, the polymeric binder (IIA) being obtainable by polymerizing

bl) 5 to 75% by weight, based on the binder (IIA), of a compound VI capable of radical polymerization which is different from the carboxylic acid or the sulfonic acid V or a derivative thereof, or a mixture of two or more thereof

and

b2) 25 to 95% by weight, based on the binder (IIA), of a further compound VII with an average molecular weight (number average) of at least 5,000 with polyether segments in the main or side chain.

The composition contained in the at least one first layer and its production will now be described in detail below.

The solid I is preferably selected from the group consisting of an inorganic solid, preferably an inorganic basic solid, selected from the group consisting of oxides, mixed oxides, carbonates, silicates, sulfates, phosphates, amides, imides, nitrides and carbides of the elements of I. ., II., III. or IV. main group or IV. subgroup of the periodic table; a polymer selected from the group consisting of polyethylene, polypropylene, polystyrene, polytetrafluoroethylene, polyvinylidene fluoride, polyamides, polyimides; containing a solid dispersion

(R) tend such a polymer; Glass powder, nanoglass particles such as Monosper (Merck), microglass particles such as Spheriglas ^® (Potters-Ballotini), nanowhiskers and a mixture of two or more thereof, whereby a composition is obtained which is used as a solid electrolyte and / or separator can be used. The term “solid III” encompasses all compounds which are present as a solid under normal conditions and which, when the battery is operated under the conditions prevailing when charging batteries, in particular lithium ion batteries, neither accept electrons nor give them off.

The solid III in this layer is primarily inorganic solids, preferably an inorganic basic solid, selected from the group consisting of oxides, mixed oxides. Silicates, sulfates, carbonates, phosphates.

Nitrides, amides, imides and carbides of the elements of I., II .. III. or IV. main group or IV. subgroup of the periodic table; a polymer selected from the group consisting of polyethylene, polypropylene, polystyrene,

Polytetrafluoroethylene, polyvinylidene fluoride, polyamides, polyimides; a solid dispersion containing such a polymer; and a mixture of two or more thereof.

Examples include: oxides, such as silicon dioxide, aluminum oxide, magnesium oxide or titanium dioxide, mixed oxides, for example the elements silicon, calcium. Aluminum, magnesium, titanium; Silicates, such as, for example, conductor, chain, layer and framework silicates. such as talc, pyrophyllite, muscovite, phlogopite. Amphiboles, Nesocilicate, Pyroxenes. Sorosilicates. Zeolites, feldspars, wollastonite, in particular hydrophobized wollastonite, mica, phyllosilicates; Sulfates, such as, for example, alkali and alkaline earth metal sulfates: carbonates, for example alkali and alkaline earth metal carbonates, such as, for example, calcium, magnesium or barium carbonate or lithium, potassium or sodium carbonate; Phosphates, for example apatite; Amides; Imides; Nitrides; Carbides; Polymers, such as polyethylene, polypropylene, polystyrene, polytetrafluoroethylene, polyvinylidene fluoride, polyamides, polyimides, or other thermoplastics, thermosets or microgels, crosslinked polymer particles, such as Agfaperl®, solid dispersions, in particular those containing the abovementioned polymers, and mixtures of two or more of the above solids. In addition, according to the invention, inorganic Li-ion-conducting solids, preferably an inorganic basic Li-ion-conducting solid, can be used as solid I.

These include: lithium borates, such as Li B ₆ On * xH ₂ O, Li ₃ (BO ₂ ) ₃ , Li ₂ B ₄ O ₇ * xH ₂ O, LiBO ₂ , where x can be a number from 0 to 20 ; Lithium aluminates, such as Li ₂ O * Al ₂ O ₃ * H ₂ O, Li ₂ Al ₂ O ₄ , LiAlO ₂ ; Lithium aluminosilicates, such as, for example, lithium-containing zeolites, feldspar, feldspar representatives, phyllo and inosilicates, and in particular LiAlSi ₂ O ₆ (spodumene), LiAlSi ₄ Oιo (petullite), LiAlSiO ₄ (eucryptite), mica, such as, for example, K [Li, Al] ₃ [AlSi] ₄ O ₁₀ (F-OH) ₂ , K [Li, Al, Fe] ₃ [AlSi] ₄ Oι ₀ (F-OH) ₂ ; Lithium zeolites, in particular those in the form of fibers, sheets or cubes, in particular those having the general formula Li _{2 / z} O * Al ₂ O ₃ * xSiO ₂ * yH ₂ O where z corresponds to the valency, x 1, 8 to about 12 and y is 0 to about 8; Lithium carbides, such as Li ₂ C ₂ , Li ₄ C; Li ₃ N; Lithium oxides and mixed oxides, such as LiAlO ₂ , Li ₂ MnO ₃ , Li ₂ O, Li ₂ O ₂ , Li ₂ MnO, Li ₂ TiO ₃ ; Li ₂ NH; LiNH ₂ ; Lithium phosphates, such as Li ₃ PO ₄ , LiPO ₃ , LiAlFPO ₄ , LiAl (OH) PO ₄ , LiFePO ₄ , LiMnPO ₄ ; Li ₂ CO ₃ ; Lithium silicates in the form of conductors, chains, layers and scaffolds, such as Li ₂ SiO ₃ , Li ₂ SiO ₄ and Li ₆ Si; Lithium sulfates, such as Li ₂ SO, LiHSO ₄ , LiKSO; and the Li compounds mentioned as compound Ib, the presence of conductive carbon black being excluded when used as solid I; and mixtures of two or more of the above-mentioned Li-ion-conducting solids.

Hydrophobized solids I are preferably used as solids I, more preferably hydrophobized compounds of the type mentioned above.

Basic solids are particularly suitable. Basic solids are to be understood to mean those whose mixture with a liquid, water-containing diluent, which itself has a pH of at most 7, has a higher pH than this diluent.

The solids should advantageously be largely insoluble in the liquid used as the electrolyte and be electrochemically inert in the battery medium. Solids I which have a primary particle size of 5 nm to 20 μm, preferably 0.01 to 10 μm and in particular 0.1 to 5 μm are particularly suitable, the specified particle sizes being determined by electron microscopy. The melting point of the pigments is preferably above the operating temperature customary for the electrochemical cell, melting points above 120 ° C., in particular above 150 ° C., having proven particularly favorable.

The pigments can be symmetrical in terms of their outer shape, i.e. have a size ratio of height: width: length (aspect ratio) of approximately 1 and as spheres, granules, approximately round structures, but also in the form of any polyhedra, such as present as a cuboid, tetrahedron, hexahedron, octahedron or as a bipyramid, or be distorted or asymmetrical, i.e. have a size ratio of height: width: length (aspect ratio) of not equal to 1 and e.g. present as needles, asymmetrical tetrahedra, asymmetrical bipyramids, asymmetrical hexahedron or octahedron, platelets, disks or as fibrous structures. If the solids are in the form of asymmetrical particles, the upper limit for the primary particle size given above relates to the smallest axis.

The composition used according to the invention comprises 1 to 99% by weight, preferably 15 to 90% by weight, more preferably 25 to 85% by weight, in particular 50 to 80% by weight of a solid I, and 1 to 99% by weight. %, preferably 10 to 85% by weight, more preferably 15 to 75% by weight, in particular 20 to 50% by weight, of the polymeric binder II or IIA.

In principle, all compounds which meet this criterion can be used as the compound IV which is capable of reacting with a carboxylic acid or a sulfonic acid V or a derivative or a mixture of two or more thereof. Compound IV is preferably selected from the group consisting of a mono- or polyhydric alcohol which has only carbon atoms in the main chain; a mono- or polyhydric alcohol that is in the main chain in addition to at least two carbon atoms, has at least one atom selected from the group consisting of oxygen, phosphorus and nitrogen; a silicon containing compound; an amine having at least one primary amino group; an amine having at least one secondary amino group; an amino alcohol; a mono- or polyvalent thiol; a compound having at least one thiol and at least one hydroxyl group; and a mixture of two or more of them.

Among these, compounds IV are preferred which have two or more functional groups which can react with the carboxylic acid or sulfonic acid.

When using compounds IN which contain amino groups as the functional group, it is preferred to use those with secondary amino groups, so that after the condensation / crosslinking either no or only small amounts of free ΝH groups are present in the binder II .

In particular, the following are to be mentioned as preferred connections:

monohydric or polyhydric alcohols which have only carbon atoms in the main chain, with 1 to 20, preferably 2 to 20 and in particular 2 to 10 alcoholic OH groups, in particular dihydric, trihydric and tetravalent alcohols, preferably with 2 to 20 carbon atoms, such as ethylene glycol, propane-1,2- or -1,3-diol, butane-1,2- or 1,3-diol, butene-1,4- or butyne-1,4-diol, hexane-1 , 6-diol, neopentyl glycol, dodecane-l, 2-diol. Glycerin, trimethylolpropane, pentaerythritol or sugar alcohols, hydroquinone, novolak, bisphenol A, but also, as is apparent from the above definition, monohydric alcohols, such as methanol, ethanol, propanol, n-, sec- or tert-butanol, etc. can be used; Polyhydroxyolefme can also. preferably those with two terminal hydroxyl groups, such as, for example, α.ω-dihydroxybutadiene, are used; Polyester polyols, as are known, for example, from Ullmann's Encyclopedia of Industrial Chemistry, 4th edition, vol. 19, pp. 62-65 and obtained, for example, by reacting dihydric alcohols with polyhydric, preferably dihydric, polycarbonates;

monohydric or polyhydric alcohols which contain at least one oxygen atom in the main chain in addition to at least two carbon atoms, preferably polyether alcohols, such as e.g. Polymerization products of alkylene epoxides, for example isobutylene oxide, propylene oxide. Ethylene oxide, 1, 2-epoxybutane, 1,2-epoxypentane, 1, 2-epoxyhexane, tetrahydrofuran, styrene oxide, polyether alcohols modified at the end groups, such as e.g. polyether alcohols modified with NH 2 end groups can be used; these alcohols preferably have a number average molecular weight of 100 to 5,000, more preferably 200 to 1,000, and in particular 300 to 800; such compounds are known per se and are commercially available, for example, under the Pluriol® or Pluronic® brands (BASF Aktiengesellschaft);

Alcohols, as defined above, in which some or all of the carbon atoms have been replaced by silicon, in particular polysiloxanes or alkylene oxide / siloxane copolymers or mixtures of polyether alcohols and polysiloxanes, as described, for example, in EP-B 581 296 and EP-A 525 728 can be used, the statements made above also relating to the molecular weight of these alcohols;

Alcohols as defined above, in particular polyether alcohols in which some or all of the oxygen atoms have been replaced by sulfur atoms, the statements made above also relating to the molecular weight of these alcohols;

monohydric or polyhydric alcohols which contain at least one phosphorus atom or at least one nitrogen atom in the main chain in addition to at least two carbon atoms, such as, for example, diethanolamine and triethanolamine; Lactones derived from compounds of the general formula HO- (CH ₂ ) _z -COOH, where z is a number from 1 to 20, such as, for example, ε-caprolactone, ß-propiolactone, Y-butyrolactone or methyl ε-caprolactone;

a silicon containing compound, e.g. Di- or trichlorosilane, phenyl-trichlorosilane, diphenyldichlorosilane, dimethylvinylchlorosilane; Silanols, e.g. Trimethylsilanol;

an amine having at least one primary and / or secondary amino group, e.g. Butvlamine, 2-ethylhexylamine, ethylene diamine, hexamethylene diamine, diethylene triamine. Tetraethylene pentamine, pentaethylene hexamine. Aniline, phenylenediamine;

Polyether diamines, e.g. 4,7-dioxydecane-l, 10-diamine, 4.11-dioxytetradecane-1,14-diamine;

a mono- or polyvalent thiol, e.g. aliphatic thiols, e.g. Methanethiol, ethanethiol, cyclohexanethiol, dodecanethiol; aromatic thiols, e.g. Thiophene, 4-chlorothiophenol, 2-mercaptoaniline;

a compound having at least one thiol and at least one hydroxyl group, e.g. 4-hydroxythiophenol and monothio derivatives of the polyhydric alcohols defined above;

Amino alcohols, e.g. Ethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, 2-amino-l-propanol, 2-amino-l-phenylethanol, mono- or polyaminopolyols with more than two aliphatically bound hydroxyl groups, such as Tris (hydroxymethyl) methylamine. Glucamine, N, N'-bis (2-hydroxyethyl) ethylenediamine.

Mixtures of two or more of the compounds IV defined above can also be used. According to the invention, the compounds IV mentioned above are condensed with a carboxylic acid or sulfonic acid N which has at least one free-radically polymerizable functional group, or a derivative thereof or a mixture of two or more thereof, at least one, preferably all, of the free groups capable of condensation within the Compounds IV are condensed with the compound V.

In principle, all carboxylic and sulfonic acids can be used as carboxylic acid or sulfonic acid V in the context of the present invention. which have at least one radically polymerizable functional group, and their derivatives are used. The term “derivatives” used here encompasses both compounds which are derived from a carbon or sulfonic acid which is modified in terms of the acid function, such as esters, acid halides or acid anhydrides, and compounds which are derived from a carbon or sulfonic acid which is modified on the carbon skeleton of the carbon or sulfonic acid, such as, for example, halocarbon or sulfonic acids.

The following are particularly to be mentioned as compound V:

α, β-unsaturated carboxylic acids or ß, γ-unsaturated carboxylic acids.

Particularly suitable α, β-unsaturated carboxylic acids are those of the formula

in which R ¹ , R ² and R ^{3 represent} hydrogen or C 1 -C ₄ -alkyl radicals, among which in turn acrylic acid and methacrylic acid are preferred; cinnamic acid, maleic acid, fumaric acid, itaconic acid or p-ninylbenzoic acid, as well as derivatives thereof such as anhydrides such as maleic or itaconic anhydride; Halides, in particular chlorides, such as, for example, acrylic or methacrylic acid chloride;

Esters, e.g. (Cyclo) alkyl (meth) acrylates with up to 20 C atoms in the alkyl radical, e.g. Methyl, ethyl, propyl, butyl, hexyl, 2-ethylhexyl, stearyl. Lauryl, cyclohexyl, benzyl, trifluoromethyl, hexafluoropyl. Tetrafluoropropyl (meth) acrylate. Polypropylene glycol mono (meth) acrylates, polyethylene glycol mono (meth) acrylates, poly (meth) acrylates of polyhydric alcohols, such as e.g. Glycerol di (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol di- or tri (meth) acrylate, diethylene glycol bis (mono- (2-acryloxy) ethyl) carbonate. Poly (meth) acrylates of alcohols, which in turn have a radical polymerizable group, such as e.g. Esters of (meth) acrylic acid and vinyl and / or allyl alcohol;

Vinyl esters of other aliphatic or aromatic carboxylic acids, such as. B.

Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl hexanoate, vinyl octanoate, vinyl decanoate. Vinyl stearate, vinyl palminate, vinyl crotonoate, divinyl adipate, divinyl sebacate, vinyl 2-ethylhexanoate. Vinyl trifluoroacetate;

Allyl esters of other aliphatic or aromatic carboxylic acids, such as. B.

Allyl acetate, allyl propionate, allyl butyrate, allyl hexanoate, Allyloctanoat, Allyldeca- noat, allyl stearate, Allylpalminat, Allylcrotonoat, Allylsalicylat, allyl lactate, diallyl oxalate, diallyl malonate, diallyl succinate, Diallylglutarat, diallyl adipate, Diallylpimelat, Diallylcinnamat, diallyl maleate, diallyl phthalate, diallyl isophthalate, Triallylbenzol- 1, 3,5-tricarboyxylate, allyl trifluoroacetate, allyl perfluorobutyrate, allyl perfluorooctanoate;

ß, γ-unsaturated carboxylic acids or their derivatives, such as. B. vinyl acetic acid, 2-methyl vinyl acetic acid, isobutyl 3-butenoate. Allyl 3-butenoate. Allyl 2-hydroxy-3-butenoate. Diketene; Sulfonic acids, such as vinylsulfonic acid, allylic and methallylsulfonic acid, and also their esters and halides, vinyl benzenesulfonic acid ester, 4-vinylbenzenesulfonic acid amide.

Mixtures of two or more of the carboxylic and / or sulfonic acids described above can also be used.

Compounds VI capable of free-radical polymerization which can be used for the preparation of the binder (IIA) can be mentioned in detail: olefinic hydrocarbons, such as e.g. Ethylene, propylene, butylene, isobutene, hexene or higher homologues and vinylcyclohexane;

(Meth) acrylonitrile;

halogen-containing olefinic compounds, e.g. Vinylidene fluoride, vinylidene chloride, vinyl fluoride, vinyl chloride, hexafluoropropene, trifluoropropene, 1,2-dichloroethylene, 1,2-difluoroethylene and tetrafluoroethylene;

Vinyl alcohol, vinyl acetate, N-vinylpyπolidone. N-vinylimidazole, vinylformamide;

Phosphorus nitride chlorides, e.g. Phosphorus dichloride nitride, hexachlor (triphosphazene), and their derivatives which are partially or fully substituted by alkoxy, phenoxy, amino and fluoroalkoxy groups, i.e. Compounds that can be polymerized to polyphosphazenes;

aromatic, olefinic compounds such as e.g. Styrene, α-methylstyrene;

Vinyl ethers, such as, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, octyl, decyl, dodecyl, 2-ethylhexyl, cyclohexyl, benzyl, trifluoromethyl, hexafluoropropyl , Tetrafluoropropyl vinyl ether. Mixtures of the above compounds VI can of course also be used, in which case copolymers are formed which, depending on the type of preparation, contain the monomers in a statistically distributed manner or give block copolymers.

These compounds VI as well as the condensation products III are polymerized in a conventional manner well known to the person skilled in the art. preferably free-radically polymerized, with regard to the molecular weights obtained what has been said hereinafter regarding compound VII.

Compounds VII are primarily compounds with an average molecular weight (number average) of at least 5,000, preferably 5,000 to 20,000,000, in particular 100,000 to 6,000,000, which are capable of solvating lithium cations and functioning as binders . Suitable compounds VII are, for example, polyethers and copolymers which have at least 30% by weight of the following structural unit, based on the total weight of compound VII:

where R ¹ , R ² , R ³ and R ^{4 are} aryl groups, alkyl groups, preferably methyl groups, or hydrogen, are the same or different and heteroatoms such as oxygen. May contain nitrogen, sulfur or silicon.

Such connections are for example in: M. B. Armand et. al., Fast Ion Transport in Solids, Elsevier, New York, 1979, pp. 131-136, or in FR-A 7832976.

Compound VII can also consist of mixtures of two or more such compounds. The polymeric binders II and IIA defined above can also be in the form of a foam, in which case the solid I as such is present distributed therein.

The compound VII advantageously has an average molecular weight (number average) of 5,000 to 100,000,000, preferably 50,000 to 8,000,000. The binder II can be reacted by reacting 5 to 100% by weight, preferably 30 to 70% by weight, based on the binder II, of at least one condensation product III and 0 to 95% by weight, in particular 30 to 70% by weight. %, based on the binder II of a compound VII, can be obtained. The compound VII of the binder IIA advantageously has an average molecular weight (number average) of 5,000 to 100,000,000, preferably 50,000 to 8,000,000. The binder IIA can be converted by reaction of 5 to 75% by weight, preferably 30 to 70% by weight, based on the binder IIA of a compound VI, and 25 to 95% by weight, in particular 30 to 70% by weight. , Based on the binder IIA, a compound VII can be obtained.

A mixture of a solid I, a condensation product III, optionally a compound VII, or a mixture of a solid III, a compound VI and a compound VII and conventional additives, such as e.g. Plasticizers, preferably plasticizers containing polyethylene oxide or polypropylene oxide, are produced.

Thermoplastic and ion-conducting polymers can be used as further polymers VIII. Worthy of particular mention are:

1) polycarbonates, e.g. Polyethylene carbonate, polypropylene carbonate, poly butadiene carbonate, polyvinylidene carbonate.

2) Homo-, block and copolymers made from a) olefinic hydrocarbons, such as ethylene, propylene, butylene, isobutene, propene, hexene or higher homologues. Butadiene, cyclopentene. Cyclohexene, norbornene, vinylcyclohexane, 1,3-pentadiene, 1,3-, 1,4-, 1,5-hexadiene, isoprene, vinyl norbones; b) aromatic hydrocarbons such as styrene and methylstyrene; c) acrylic acid or methacrylic acid esters, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, octyl, decyl, dodecyl, 2-ethylhexyl, cyclohexyl, benzyl, trifluoromethyl, Hexafluoropropyl, tetrafluoropropyl acrylate or methacrylate; d) acrylonitrile, methacrylonitrile, N-methylpyrrolidone, N-vinylimidazole,

Vinyl acetate; e) vinyl ethers, e.g. Methyl-. Ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, octyl, decyl, dodecyl, 2-ethylhexyl, cyclohexyl, benzyl, trifluoromethyl, hexafluoropropyl, tetrafluoropropyl vinyl ether;

(f) Polymers and copolymers of halogen-containing olefinic compounds such as e.g. Vinylidene fluoride, vinylidene chloride, vinyl fluoride, vinyl chloride, hexafluoropropene, trifluoropropene, 1, 2-dichlorethylene, 1,2-difluoroethylene and tetrafluoroethylene; preferably polymers or copolymers of vinyl chloride. Acrylonitrile, vinylidene fluoride; Copolymers of vinyl chloride and vinylidene chloride, vinyl chloride and acrylonitrile, vinylidene fluoride and hexafluroporpylene. Vinylidene fluoride with hexafluoropropylene; Terpolymers of vinylidene fluoride and hexafluoropropylene and a member of the group consisting of vinyl fluoride, tetrafluoroethylene and a trifluoroethylene; in particular a copolymer of vinylidene fluoride and hexafluoropropylene; and more preferably a copolymer comprising 75 to 92% by weight vinylidene fluoride and 8 to 25 hexafluoropropylene. g) 2-vinyl pyridine, 4-vinyl pyridine, vinylene carbonate.

If necessary and / or desired, regulators such as mercaptans can be used in the production of the abovementioned polymers. ) Polyurethanes, for example obtainable by the implementation of

a) organic diisocyanates with 6 to 30 carbon atoms, e.g. aliphatic noncyclic diisocyanates, e.g. 1,5-hexamethylene diisocyanate and 1,6-hexamethylene diisocyanate. aliphatic cyclic diisocyanates, e.g. 1,4-cyclohexylene diisocyanate, dicyclohexyl methane diisocyanate and isophorone diisocyanate or aromatic diisocyanates such as e.g. Toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, m-tetramethylxylene diisocyanate, p-tetramethylxylene diisocyanate, 1,5-tetrahydronaphthylene diisocyanate and 4,4'-diphenylene methane diisocyanate or mixtures of such compounds, with b) polyhydric alcohols , such as Polyesterols, polyetherols and diols.

The polyesterols are advantageously predominantly linear polymers with terminal OH groups, preferably those with two or three, in particular two, OH groups. The acid number of the polyesterols is less than 10 and preferably less than 3. The polyesterols can easily be esterified by aliphatic or aromatic dicarboxylic acids having 4 to 15 carbon atoms, preferably 4 to 6 carbon atoms, with glycols, preferably glycols Produce 2 to 25 carbon atoms or by polymerizing lactones with 3 to 20 carbon atoms. Examples of dicarboxylic acids are glutaric acid and pimelic acid.

Use suberic acid, sebacic acid, dodecanoic acid and preferably adipic acid and succinic acid. Suitable aromatic dicarboxylic acids are terephthalic acid, isophthalic acid, phthalic acid or mixtures of these dicarboxylic acids with other dicarboxylic acids, for example diphenic acid, sebacic acid, succinic acid and adipic acid. The dicarboxylic acids can be used individually or as mixtures. For the preparation of the polyesterols it may be advantageous to use the instead of the dicarboxylic acids to use corresponding acid derivatives, such as carboxylic acid anhydrides or carboxylic acid chlorides. Examples of suitable glycols are diethylene glycol, 1,5-pentanediol, 1,10-decanediol and 2,2,4-trimethylpentanediol-1,5. 1,2-ethanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2,2-dimethyl-propanediol-1,3 are preferably used , 1, 4-dimethylolcyclohexane, 1,4-diethanolcyclohexane and ethoxylated or propoxylated products of 2,2-bis (4-hydroxyphenylene) propane (bisphenol A). Depending on the desired properties of the polyurethanes, the polyols can be used alone or as a mixture in various proportions. Suitable lactones for the production of the polyesterols are, for example .α-dimethyl-β-propiolactone, γ-butyro-lactone and preferably ε-caprolactone.

The polyetherols are essentially linear substances with terminal hydroxyl groups and contain ether bonds. suitable

Polyetherols can easily be prepared by polymerizing cyclic ethers, such as tetrahydrofuran, or by reacting one or more alkylene oxides having 2 to 4 carbon atoms in the alkylene radical with a starter molecule which contains two active hydrogen atoms bound in the alkylene radical. Examples of alkylene oxides are ethylene oxide, 1,2-propylene oxide, epichlorohydrin and 1,2-butylene oxide. Called 2,3-butylene oxide. The alkylene oxides can be used individually, alternately in succession or as a mixture. For example, water, glycols such as ethylene glycol are used as starter molecules. Propylene glycol, 1,4-butanediol and 1,6-hexanediol, amines such as ethylenediamine, hexamethylenediamine and 4,4'-diamino-diphenylmethane and amino alcohols such as ethanolamine. Suitable polyesterols and polyetherols and their preparation are described, for example, in EP-B 416 386, suitable polycarbonate diols, preferably those based on 1,6-hexanediol, and their preparation, for example, in US Pat. No. 4,131,731. In amounts of up to 30% by weight, based on the total mass of the alcohols, aliphatic diols having 2 to 20, preferably 2 to 10, carbon atoms, such as 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1, 6-hexanediol, 1,5-pentanediol, 1,10-decanediol, 2-methyl-l, 3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-2-butyl-l, 3-propanediol, 2,2-dimethyl-1,4-butanediol, 1,4-dimethylolcyclohexane, hydroxypivalic acid neopentyl glycol ester, diethylene glycol, triethylene glycol and methyl diethanolamine or aromatic-aliphatic or aromatic-cycloaliphatic diols with 8 to 30 carbon atoms, where as aromatic structures heterocyclic ring systems or preferably isocyclic ring systems such as naphthalene or in particular benzene derivatives such as bisphenol A, double symmetrically ethoxylated bisphenol A, double symmetrically propoxylated bisphenol A, more ethoxylated or propoxylated bisphenol A derivatives or bisphenol F derivatives and mixtures thereof Connections come into consideration n.

In amounts of up to 5% by weight, based on the total mass of the alcohols, advantageously aliphatic triols having 3 to 15, preferably 3 to 10 carbon atoms, such as trimethylolpropane or glycerol, the reaction product of such compounds with ethylene oxide and / or propylene oxide and mixtures of such connections.

The polyhydric alcohols can carry functional groups, for example neutral groups such as siloxane groups, basic groups such as, in particular, tertiary amino groups or acidic groups or their salts or groups which easily change into acidic groups, via a polyvalent group

Alcohol are introduced. Diol components which carry such groups, such as N-methyldiethanolamine, N, N-bis (hydroxyethyl) aminomethylphosphonic acid diethyl ester or N, N-bis (hydroxyethyl) -2-aminoacetic acid (3-sulfopropyl) ester or dicarboxylic acids, can preferably be used. which carry such groups and can be used for the production of polyesterols, such as 5-sulfoisophthalic acid. Acid groups are especially the phosphoric acid, phosphonic acid, sulfuric acid, sulfonic acid, carboxyl, or ammonium group.

Groups that easily change into acidic groups are, for example, the ester group or salts, preferably of the alkali metals such as lithium,

Sodium or potassium.

4) The polyesterols described above per se, whereby it should be noted. that molecular weights in the range of 10,000 to 2,000,000, preferably 50,000 to 1,000,000, are obtained.

5) Polyamines, polysiloxanes and polyphosphazenes, especially those as have already been discussed in the description of polymer IIb2.

6) polyetherols, such as. B. in the above discussion of the polymer Ilbl as compound (c) or in the discussion of polyurethanes.

Mixtures of the above polymers VIII can of course also be used. Depending on the type of preparation, the copolymers VIII used according to the invention can contain the monomers in a statistically distributed manner or be present as block copolymers.

The polymer VIII is polymerized in a conventional manner, which is well known to the person skilled in the art, preferably polymerized by free radicals. The polymer VIII can be used both in high molecular weight or oligomeric form or as mixtures thereof.

The proportion of polymer VIII in the polymeric binder II to IIA is generally 0 to 99% by weight, preferably 20 to 80% by weight and more preferably 40 to 70% by weight. The present invention preferably relates to composite bodies with a first layer, which comprises the following compositions:

First layers as defined above, wherein the polymer VIII is selected from the group consisting of a polymer or copolymer of vinyl chloride, acrylonitrile, vinylidene fluoride; a copolymer of vinyl chloride and vinylidene chloride, vinyl chloride and acrylonitrile, vinylidene fluoride and hexafluoropropylene, vinylidene fluoride with hexafluoropropylene; a terpolymer of vinylidene fluoride and hexafluoropropylene and a member of the group consisting of vinyl fluoride, tetrafluoroethylene and a trifluoroethylene and preferably a copolymer of vinylidene fluoride and hexafluoropropylene.

The compositions used according to the invention may further contain a plasticizer IX. However, it is also possible to work without a plasticizer.

If present, the proportion of plasticizer IX, based on the composition, is 0.1 to 100% by weight, preferably 0.5 to 50% by weight and in particular 1 to 20% by weight.

As plasticizer IX e.g. the plasticizers described in DE-A 198 19 752 are used, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethylene carbonate, 1,2-propylene carbonate, 1,3-propyl encarbonate, organic phosphorus compounds, in particular phosphates and phosphonates, such as e.g. Trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tris (2-ethylhexyl) phosphate. Polyalkylene oxide ethers and esters, e.g. Diglyme, triglyme and tetraglyme compounds, polymeric plasticizers such as e.g. thermoplastic polyurethanes or polyamides, and mixtures thereof are preferred.

The compositions used according to the invention can be in an inorganic or organic, preferably an organic liquid Diluents are dissolved or dispersed, the mixture according to the invention should have a viscosity of preferably 100 to 50,000 mPas, and then in a manner known per se, such as spray coating, pouring. Diving, spin coating, roller coating, printing in high-pressure. Gravure or planographic printing or screen printing, can be applied to a carrier material. Further processing can be carried out as usual, for example by removing the diluent and curing the mixture.

Suitable organic diluents are aliphatic ethers, in particular tetrahydrofiiran and dioxane, hydrocarbons, in particular hydrocarbon mixtures such as gasoline, toluene and xylene, aliphatic esters, in particular ethyl acetate and butyl acetate and ketones, in particular acetone, ethyl methyl ketone and cyclohexanone, and also DMF and NMP. Combinations of such diluents can also be used.

The materials usually used for electrodes, preferably metals such as aluminum and copper, come into consideration as carrier material. Temporary intermediate carriers, such as films, in particular polyester films, such as polyethylene terephthalate films, can also be used. Such films can advantageously be provided with a separating layer, preferably made of polysiloxanes.

The separators can also be produced thermoplastic, for example by injection molding or melt casting. Pressing, kneading or extruding, if appropriate with a subsequent calendering step of the composition used according to the invention.

After filming of the composition used according to the invention, volatile components such as solvents or plasticizers can be removed.

The composition used according to the invention can be crosslinked in a manner known per se, for example by ionic radiation or ionizing radiation, electron beam, preferably with an acceleration voltage between 20 and 2,000 kV and a radiation dose between 5 and 50 Mrad, UV or visible light, an initiator such as benzil dimethyl ketal or 1,3,5-trimethylbenzoyl-triphenylphosphine advantageously being used in the usual way oxide in amounts of in particular not more than 1% by weight, based on the polymeric binder II / IIA, can be added and the crosslinking can be carried out within generally from 0.5 to 15 minutes; by thermal crosslinking via radical polymerisation, preferably at temperatures above 60 ° C. an initiator such as azo-bis-isobutyronitrile can advantageously be added in amounts of generally at most 5% by weight, preferably 0.05 to 1% by weight, based on the polymeric binder II / IIA; by electrochemically induced polymerization: or by ionic polymerization, for example by acid-catalyzed cationic polymerization, the catalysts used primarily being acids, preferably Lewis acids such as BF ₃ , or in particular LiBF ₄ or LiPF ₆ . Catalysts containing lithium ions such as LiBF ₄ or LiPF ₆ can advantageously remain in the solid electrolyte or separator as the conductive salt.

The crosslinking described above is preferably carried out under inert gas. According to the invention, the exposure time can be controlled so that either complete crosslinking takes place or is only briefly pre-irradiated with UV light, so that only partial crosslinking takes place.

As mentioned at the beginning, the at least one second layer of the molded body according to the invention comprises a conventional separator. All conventional separators can be used according to the invention. The following should be mentioned in particular:

Separators based on microporous polyolefin films as they are commercially available, for example under the trade names Celgard ^®, Hipore and inter alia, EP-A 0718901 and EP-B 0715364, both fully into the context of the present application by Reference to be included; there are polyethylene and Polypropylene films, and films which contain blends of polyethylene or polypropylene with other polymers, can also be used well; microporous polytetrafluoroethylene (PTFE) films from Goretex, as described, for example, in EP-A 0 798 791, which is also incorporated by reference into the context of the present application;

Nonwovens, fibers, and non-woven textile composites, so-called "nonwovens", all of which can be produced using fibrous polymer materials, such as, for example, polyolefin, polyamide and polyester fibers;

Films available under the trade name Nafion; Films based on a copolymer of vinylidene difluoride and hexafluoropropene, as described, for example, in US Pat. No. 5,540,741 and US Pat. No. 5,478,668; Filler-containing, available through extrusion homo-, block and copolymers, made from

(a) olefinic hydrocarbons such as e.g. Ethylene, propylene, butylene, isobutene, propene, hexene or higher homologues, butadiene, cyclopentene, cyclohexene. Norbornen. Vinylcyclohexane; (b) aromatic hydrocarbons such as e.g. Styrene and methylstyrene;

(c) acrylic acid or methacrylic acid esters, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, octyl, decyl, dodecyl, 2-ethylhexyl, cyclohexyl, benzyl, Trifluoromethyl, hexafluoropropyl, tetrafluoropropyl acrylate or methacrylate; (d) acrylonitrile, methacrylonitrile, N-methylpyπolidone, N-vinylimidazole,

Vinyl acetate;

(e) vinyl ethers such as Methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, octyl, decyl. Dodecyl, 2-ethylhexyl, cyclohexyl, benzyl, trifluoromethyl, hexafluoropropyl, tetrafluoropropyl vinyl ether;

(f) halogen-containing olefinic compounds such as vinyl chloride, vinyl fluoride, vinylidene fluoride, vinylidene chloride, hexafluoropropene, Trifluoropropene, 1, 2-dichloroethene, 1,2-difluoroethene. Tetrafluoroethene,

the solids (I) according to the invention being used as filler in these polymers; Such extruder films are in the

DE-A 197 13 072.0 described in detail with regard to their composition and manufacture.

To produce the composite body according to the invention, the at least one first layer is brought together with the at least one second layer, it being possible to use all known methods for bringing such layers together according to the invention. For example, the application of the first layer to the second layer can be carried out by non-pressure processes, such as, for example, casting or knife coating the starting material for the first layer, and by processing processes under pressure, such as extrusion. Laminating, in particular hot lamination, laminating, calendering or pressing. The composite body produced in this way can be crosslinked or hardened by radiation, electrochemically or thermally. In addition, the starting material for the at least one first layer can first be wholly or partially thermally crosslinked or cured and then, as described above, brought together with the second layer used according to the invention without pressure or under pressure. If already prepared films, ie the at least one first layer in the form of a film and the conventional separator in the form of a film are to be brought together, this is preferably done by lamination, temperatures generally in the range from about 50 to about 160 ° C., preferably about 70 to about 120 ° C can be used, the exact temperatures used depending in particular on the conventional separator used. For example, polypropylene films can be used at slightly higher temperatures than polyethylene films. Even in the production of the composite body by lamination, the composition of the first layer can be fully or partially crosslinked and the composite body obtained after lamination can be crosslinked again as required or can be used directly without postcrosslinking.

When using the composite body according to the invention as a separator in an electrochemical cell, the composite body is combined with conventional anodes and cathodes. In addition, a dissociable compound containing lithium cations, a so-called conductive salt, and possibly other additives, such as, in particular, organic solvents, a so-called electrolyte, are inkoφoriert. The latter substances can be mixed partially or completely in the manufacture of the composite body according to the invention or introduced after the manufacture thereof.

The generally known conductive salts, described for example in EP-A 0 096 629, can be used as conductive salts. According to the invention, LiPF ₆ , LiBF, LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (SO ₂ C _n F ₂ “ ₊ ι ) 2, LiC [(C _n F _{2n +} .) SO ₂ ] ₃ , Li (C _n F _{2n +} ι) SO ₂ , with n each 2 to 20, LiN (SO ₂ F) ₂ , LiAlCl ₄ , LiSiF ₆ , LiSbF ₆ , (RSO ₂ ) _n XLi ( _n X = ιO, iS, ₂ N, ₂ P, 3C, ₃ Si; R = C _m F _{2m +} ι with m = 0-10 or C1-C20 hydrocarbons), Li Imide salts, Li-methide salts, or a mixture of two or more thereof, LiPF ₆ being particularly preferably used as the conductive salt.

Suitable organic electrolyte solvents are the compounds discussed above under “plasticizers”, preference being given to using the customary organic electrolytes, preferably esters such as ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate, or mixtures of such compounds.

The composite body according to the invention advantageously has a thickness of 5 to 500 μm, preferably 10 to 500 μm, more preferably 10 to 200 μm and in particular 15 to 100 μm. The composite body can be assembled with the anodes and cathodes to form an electrochemical cell, which in turn is a solid composite. This composite advantageously has a total thickness of 30 to 2000 μm, in particular a total thickness of 50 to 1000 μm.

The present invention further relates to a method for producing such a composite body, which comprises the following stages:

(A) making at least a first layer as defined above; (B) making at least a second layer as defined above; and

(C) then bringing the at least one first layer together with the at least one second layer by a conventional coating method.

The at least one first layer is preferably produced on a temporary carrier. Temporary carriers commonly used according to the invention, such as e.g. a release film made of a polymer or a preferably coated paper, e.g. a siliconized polyester film can be used. However, the production of this first layer is also on a permanent support, e.g. an arrester electrode or even completely without a carrier.

The layers defined above are brought together or produced by pressureless processes for coating or producing foils, such as Casting or knife coating, as well as by processing methods under pressure, e.g. Extruding, laminating, in particular hot lamination, laminating, calendering or pressing. If necessary, the composite body produced in this way can be crosslinked or hardened by radiation, electrochemically or thermally.

Furthermore, it is possible to bring together the composite body according to the invention with conventional electrodes by means of the methods described above to provide a composite with the components (separating film / separator / electrode).

It is also possible to provide a composite with the components anode / separator / cathode by double-sided coating of the composite body.

The composite body can be laminated as a separator and with the anode foil and / or cathode foil together at temperatures> 80 ° C. It is easily possible, e.g. to laminate the composite body according to the invention on a conventional anode or cathode, a composite anode or cathode / separator being obtained, which in turn can then be combined with a conventional cathode or anode to form a composite body comprising a cathode-separator-anode.

A composite anode / separator / cathode as described above can also be produced without the use of a carrier or the arrester electrodes, since the composite body according to the invention containing at least one first and at least one second layer, as defined above, per se for use in electrochemical Cells has sufficient mechanical stability.

The filling of such composites or the electrochemical cell with an electrolyte and conductive salt can be carried out either before the layers are brought together or preferably after the layers have been brought together, if necessary after contacting them with suitable discharge electrodes, for example a metal foil, and even after the composite body or of the composite take place in a battery housing, the special microporous structure of the layers in the composite body according to the invention, in particular due to the presence of the solid I defined above, allowing the electrolyte and the conductive salt to be sucked up and the air to be displaced in the pores. The infestation can be carried out at temperatures from 0 ° C. to approximately 100 ° C., depending on the electrolyte used. The electrochemical cells according to the invention can be used in particular as a car, device or flat battery and as an on-board battery, battery for static applications and battery for electric traction.

The composite body according to the invention has the following advantages over the separators hitherto intended for use in electrochemical cells: due to the combination of a conventional separator and the composition containing a solid I, a composite body is obtained which has extraordinary mechanical stability, in particular excellent dimensional stability and has improved compressive strength; the composite body according to the invention can be used in battery manufacture on commercially available automatic winding machines, such as those used there, without any problems; the composite body according to the invention represents a separator with a shutdown mechanism (shutdown mechanism).

The present invention will now be explained with the aid of a few examples.

EXAMPLES

Production Example 1: Production of a separator film

75 g of a hydrophobicized with Epoxsilan wollastonite (Tremin ^® 800 EST, Quarzwerke Frechen) microns with a particle size of 3, was dispersed using a high speed in 300 g of toluene. Subsequently, to the mixture 12.5 g of a polyethylene oxide having an average molecular weight of Mw = 2,000,000 (Polyox ^®, Union Carbide), 12.5 g Methacrylsäurediester of a propylene oxide-ethylene block copolymer (Pluriol ^® PE 6000 from BASF AG) and 0:02 g of a UV-photoinitiator (Lucirin ^® BDK, BASF AG). The mixture was then applied to a siliconized polyethylene terephthalate film at 60 ° C. using a doctor blade with a casting gap of 300 μm, the toluene was removed within 5 minutes and an approximately 30 μm thick film was obtained after the dried coating had been peeled off.

Production Example 2: Production of a PEO adhesive layer

6 g of polyethylene oxide having an average molecular weight of Mw = 2,000,000 (Polyox ^®, Union Carbide) were dissolved in 300 g of toluene. The solution was knife-coated onto a siliconized polyethylene terephthalate film at 60 ° C. so that the PEO adhesive layer had a layer thickness of about 3 μm.

example

To produce the composite body, the two films were intimately bonded to one another at 80 ° C. using a Ibica laminator, type IL12HR. The siliconized polyethylene terephthalate film on the PEO adhesive layer side was then removed. On the PEO adhesive layer side, a commercially available separator film of the type Celgard ^® 2300 (Hoechst Celanese). The two films were then intimately connected to one another at 80 ° C. using the laminator. After cooling, the second siliconized polyethylene terephthalate film could be removed from the composite separator film.

Claims

claims

Composite body, comprising at least a first layer containing a composition

(a) 1 to 99% by weight of a solid (I) with a primary particle size of 5 nm to 100 μm or a mixture of at least two solids, (b) 99 to 1% by weight of a polymeric binder (II) by

Polymerization of bl) 5 to 100 wt .-%, based on the binder (II), a condensation product III from α) at least one compound IV, which is capable of with a carboxylic acid or a sulfonic acid or

To react derivative or a mixture of two or more thereof, and β) at least 1 mole per mole of compound IV one

Carboxylic acid or sulfonic acid N which has at least one radically polymerizable functional group, or a derivative thereof or a mixture of two or more thereof and b2) 0 to 95% by weight, based on the binder (II), of a further compound VII with an average molecular weight

(Number average) of at least 5,000 with polyether segments in the main or side chain, comprises, wherein the at least one first layer is applied to at least one second layer comprising at least one conventional separator.

2. Verbundköφer according to claim 1, wherein the at least a first layer comprises a polymeric binder (IIA), which is obtainable by polymerization of bl) 5 to 75 wt .-%, based on the binder (IIA), one capable of radical polymerization Compound VI other than carboxylic acid or sulfonic acid V or one

Is a derivative thereof, or a mixture of two or more thereof and b2) 25 to 95% by weight, based on the binder (IIA), of a further compound VII with an average molecular weight (number average) of at least 5,000 with polyether segments in main or

Side chain.

3. Verbundköφer according to claim 1 or 2, wherein the at least one conventional separator is selected from the group consisting of a microporous polyolefin film and a polytetrafluoroethylene

Foil.

4. Verbundköφer according to one of claims 1 to 3, wherein the solid I is selected from the group consisting of an inorganic solid, selected from the group consisting of oxides,

Mixed oxides, silicates, sulfates, carbonates, phosphates, nitrides, amides, imides and carbides of the elements of I., II., III. or IV. main group or IV. subgroup of the periodic table; a polymer selected from the group consisting of polyethylene, Polypropylene, polystyrene, polytetrafluoroethylene, polyvinylidene fluoride; Polyamides; Polyimides; and a solid dispersion containing such a polymer; and a mixture of two or more of them.

5. Verbundköφer according to one of claims 1 to 4, wherein the at least one first layer comprises at least one further polymer VIII, which is selected from the group consisting of a polymer or copolymer of vinyl chloride, acrylonitrile, vinylidene fluoride; a copolymer of vinyl chloride and vinylidene chloride, vinyl chloride and acrylonitrile, vinylidene fluoride and hexafluropropylene, vinylidene fluoride with hexafluoropropylene; a Teφolymer of vinylidene fluoride and hexafluoropropylene and a member of the group consisting of vinyl fluoride, tetrafluoroethylene and a trifluoroethylene.

6. Verbundköφer according to claim 5, wherein the polymer VIII is a copolymer of vinylidene fluoride and hexafluoropropylene.

7. Separator comprising at least one composite body according to one of claims 1 to 6.

8. An electrochemical cell comprising a separator according to claim 7.

9. A method of making a composite body according to any one of claims 1 to 6, comprising the steps of: (A) making at least a first layer as in one of the

Claims 1 to 6 defined;

(B) making at least a second layer as defined in any one of claims 1 to 6; and (C) subsequently bringing the at least one first layer together with the at least one second layer by a conventional coating method.

10. The method according to claim 9, wherein the bringing together of the at least one first layer and the at least one second layer, comprising at least one separator, by contacting the at least one first layer onto the at least one conventional separator or by lamination, preferably lamination with the action of heat, of the at least a first layer is carried out on the at least one conventional separator.