DE102004033345A1 - Flame protective high energy-lithium-polymer-cell, useful in preparing high energy-lithium-polymer-battery, comprises anode and cathode comprising an arrestor and an active electrodes mass with e.g. binding agent, respectively - Google Patents

Abstract

Flame protective high energy-lithium-polymer-cell (I) comprises an anode and cathode comprising an arrestor and an active electrodes mass with at least a flame retarding fluoro compound and a binding agent, respectively. Independent claims are also included for: (1) the preparation of (I); and (2) preparation of a high-energy lithium polymer battery comprising an anode, a cathode and an intermediate separator, where (I) is combined to a compound system, and enclosed to a battery and are polarized.

Description

The This invention relates to flame retardant high energy lithium polymer batteries and process for their preparation.

Lithium polymer batteries with electrodes and separators suitable for high-energy applications, are known in the art. Batteries are also known where the electrodes, i. the anode or cathode, from one Arrester and an applied electrode mass built up are. For the electrode mass is e.g. active electrode materials in a polymer binder, optionally with conductivity-enhancing additives embedded.

In This relationship is at discharge rates of 0.01 to 1C is from High energy and at discharge currents of> 1C to 10C of high power spoken.

J. of Power Sources 113 [2003] 166-172 discloses tris (2,2,2) trifluoroethyl phosphite (TTFP) for non-flammable electrolytes in lithium-ion batteries in amounts of about 15% by weight in combination with 1MLiPF ₆ in 3: 3: 4 PC / EC / EMC. From WO 98/15025, for example, fluorinated ethylene carbonate and from EP 0 807 986 are partially fluorinated ethers of the formula RO [(CH ₂ ) _m O] _n -CF ₂ -CFHX known, which can be used as electrolyte additives.

US Pat. No. 5,830,600 describes non-flammable self-extinguishing electrolytes which optionally contain CO ₂ -developing components.

task The present invention is to provide electrodes and improved high energy lithium polymer cells Batteries and an improved process for their preparation to disposal to deliver. In particular, it is an intent to high-energy lithium polymer batteries with improved physical properties, improved lifetime and to develop adequate flame retardancy.

These Task can e.g. by the high energy lithium polymer cells according to claim 1, the manufacturing method for high energy lithium polymer cells according to claim 23 or the method of manufacturing a high energy lithium polymer battery according to claim 36 solved become. Preferred embodiments are in the dependent claims Are defined.

Especially the intention is to use a lithium ion battery with high energy content e.g. To develop> 45 A / h, Those in Lithium Ion Batteries edit. M. Wakihara, O. Yamamoto [1998] Verlag VCH-Weinheim p. 91 presented security guidelines equivalent. These are in detail

• 1. Outer short circuit test
• 2. Overload test
• 3. Forced discharge
• 4th shock test
• 5. Nail test

The minimal requirements of the security policies for the points 1, 4, 5 are: no development of smoke or fire, beyond is the survive a thermal stability test 150 ° C desired.

• a) Perfluoralkyl, -cycloalkyl und/oder -aryl-Verbindungen mit C₂ – C₁₀ und Siedepunkten von 30 bis 250°, bevorzugt 30 bis 130°C, und haben einen Dampfdruck von 0,01 bis 85 k/Pa, bevorzugt 3 bis 45k/Pa.
• b) Fluoralkylether mit mindestens einer Perfluoralkoxygruppe R-O-R₁, wobei R₁ = CH₃, C₂H₅, C₃H₇, C₄H₉ und R = Perfluoralkyl mit C₂ – C₁₀, bevorzugt mit C₂ – C₆ ist, mit Siedepunkten von 30 bis 250°, bevorzugt 30 bis 130°C, und einem Dampfdruck von 0,01 bis 85 k/Pa, bevorzugt 3 bis 45k/Pa.

The inventively preferred flameproof high energy lithium polymer cell is a cell in which the anode and cathode each comprise a trap and an active electrode mass, with at least one flame retardant fluorine compound and a binder. The flame retardant fluorine compounds are preferred

• a) perfluoroalkyl, cycloalkyl and / or aryl compounds with C ₂ -C ₁₀ and boiling points of 30 to 250 °, preferably 30 to 130 ° C, and have a vapor pressure of 0.01 to 85 k / Pa, preferably 3 up to 45k / Pa.
• b) fluoroalkyl ethers having at least one perfluoroalkoxy group ROR ₁ , wherein R ₁ = CH ₃ , C ₂ H ₅ , C ₃ H ₇ , C ₄ H ₉ and R = perfluoroalkyl with C ₂ - C ₁₀ , preferably with C ₂ - C ₆ , with boiling points of 30 to 250 °, preferably 30 to 130 ° C, and a vapor pressure of 0.01 to 85 k / Pa, preferably 3 to 45k / Pa.

The flame-retardant fluorine compounds preferably have a molecular weight of up to 900, more preferably a molecular weight of 250 to 650, and are in amounts of preferably 5-45 wt .-%, more preferably 10-25 wt .-%, based on the total weight of the electrode composition contain. In the flame-retardant lithium polymer cell of the invention, the binder is preferably selected from fluoropolymers, polyolefins based on ethylene, propylene, isobutene, butene, styrene, butadiene and / or isoprene as homopolymers or copolymers, and optionally other unsaturated comonomers, wherein the binder particularly preferably comprises a terpolymer based on polyvinylidene fluoride, hexafluoropropylene and a perfluoroalkoxy ether and is contained as a polymer dispersion. The polymer dispersion is preferably a primary or secondary dispersion based on water or other auxiliary liquids or media. The active electrode material for the anode preferably comprises Li intercalatable carbon, preferably in the form of powders or fibers. The cathode active electrode material preferably comprises a Li intercalatable metal oxide, wherein the Li intercalatable metal oxide is preferably an oxide of a higher valence metal selected from Mn, Ti, Co, Ni, W, Mo and Cr, and preferably in the form of Powders or nanoparticles is. The active electrode material is preferably contained to 50-80 wt .-%, based on the total weight of the electrode mass. Li-organoborates and / or LiPF ₆ can be used as the conductive salt for the flameproof high-energy lithium polymer cell according to the invention. The solvents used are preferably aprotic solvents selected from alkyl carbonates, glycol ethers and perfluoroethers, it being possible for the conductive salts and / or aprotic solvents to be present in microencapsulated form. The conductive salts and / or solvents are preferably present at from 5 to 20% by weight, based on the total weight of the electrode composition. The flameproof high-energy lithium polymer cell according to the invention contains polymers such as polyvinylpyrrolidone or fluoroelastomers and / or additives selected from MgO, Al ₂ O ₃ , SiO ₂ and silicates. The deposited primer layer may comprise graphite, carbon black, conductive carbon black, Sn powder, a Li borate, a conductive polymer, or a combination thereof. The thickness of the preferably calendered layer of the electrode mass is preferably 10 to 50 μm.

• (i) Herstellen einer Elektrodenmaterialmischung durch Vermischen von Li-interkalationsfähigem aktivem Elektrodenmaterial, Leitsalz, Lösungsmitteln und wenigstens einer flammhemmenden Fluorverbindung;
• (ii) Vermischen der Elektrodenmaterialmischung mit einem Bindemittel;
• (iii) Homogenisieren der gesamten Mischung bis die Elektrodenmasse als eine einphasige Suspension vorliegt;
• (iv) Aufbringen der aktiven Elektrodenmasse als homogene Beschichtung auf den Ableiter;
• (v) Einstellen der Elektrodenmasse auf eine gewünschte Schichtdicke.

A preferred method according to the invention for the production of flame-retardant high-energy lithium polymer cells, wherein the anode and cathode preferably each comprise an arrester and an active electrode mass, comprises the following steps:

• (i) preparing an electrode material mixture by mixing Li intercalatable active electrode material, conductive salt, solvents and at least one flame retardant fluorine compound;
• (ii) mixing the electrode material mixture with a binder;
• (iii) homogenizing the entire mixture until the electrode mass is present as a single-phase suspension;
• (iv) applying the active electrode material as a homogeneous coating on the arrester;
• (v) adjusting the electrode mass to a desired layer thickness.

In In this method, the flame retardant fluorine compound is preferable like already mentioned before Are defined.

The The binder used in this process is preferred as a polymer dispersion used, wherein the polymer dispersion preferably as a primary or secondary dispersion used on the basis of water or other auxiliary fluids or media becomes. The active electrode material is preferably 50-80% by weight, based on the total weight of the electrode mass used. The Conducting salts and / or aprotic solvents are preferably microencapsulated, wherein the conductive salts and / or Solvent preferred to 5 to 20% by weight, based on the total weight of the electrode mass, be used. The single-phase suspension of the electrode mass can be applied continuously or discontinuously to the arrester become. In the method according to the invention can before applying the electrodeposition on the arrester, in particular for the cathode, a primer layer can be applied as an intermediate layer. The application the primer layer can be applied by means of liquid or spray coating respectively.

In a further preferred method for producing a high-energy lithium-polymer battery, with an anode, a cathode and an intervening separator, can the according to the before described cell to a composite system combined, and be housed and polarized into a battery.

In a preferred method of making electrodes for high energy lithium polymer batteries be intercalatable active electrode materials, conductive salts, solvent and optional, battery-specific additives for so-called electrode material mixture mixed. For this purpose, a binder is added, preferably the flame-retardant additives contains as swelling agent, and intimately mixed, then to the entire mixture for so long Homogenize until a single-phase suspension is present, which as Electrode mass can be used.

After that Preferably, the application of the electrode material is carried out as a single-phase Suspension on the trap to produce a homogeneous coating. Subsequently the electrode mass applied to the arrester is preferred by calendering to a desired one Layer thickness set. Other methods of manufacturing the electrodes can e.g. continuous extrusion or liquid coating followed by drying be.

The thus obtained electrode is through a trap and on one applied homogeneous coating layer of an electrode material characterized by good physical properties, e.g. a long life expectancy of the electrode when used in one High-energy lithium polymer battery can guarantee.

in the The following are illustrative of other aspects, benefits and effects of preferred embodiments of the manufacturing method of the invention for electrodes explained.

1st preferred embodiment

In this embodiment A preferred method of manufacturing an anode will be described. The Electrode material mixture for an anode can e.g. contain the following components:

AI: active anode material

The active anode material is preferably a lithium intercalatable carbon. Examples of the carbon are synthetic or natural graphite, MCMB ^®, SGB ^® or similar. The active anode material may be used in the form of powders or fibers and is preferably used in an amount of about 50 to 85% by weight, based on the total weight of the electrode mass.

AII: Additions

The active anode material may further include optional, battery-specific additives, eg, at 1-10 wt%, based on the total electrode mass. Preferred additives are polymers such as polyvinylpyrrolidone, fluoroelastomers such as Kynar 2801 ^®, Kynar 761 ^®, or Sn powder as well as MgO, Al ₂ O _3, SiO ₂ or other silicates or borates.

AIII: flame retardant on Base of perfluoroether

The flame retardants are preferably Novec ^™ type fluorinated ethers (the 3 M Comp.) And perfluorinated alkanes of the Fluorinert ^™ Electronic Liquids type (3 M Comp., Neuss).

In particular, for example, Methoxynonafluorbutan C ₄ F ₉ OCH ₃ , Novec HFE 7100 ^® , trifluoromethyl-3-ethoxydecafluorohexane Novec HFE 7500 ^® or HFE 7200 ^® or Fluorinert TM ^® Electronic Liquids eg FC 72, 84, 77, 75, 3238, 40 o. ä. in amounts of 10 to 25 wt .-%, based on the total electrode mass, can be used.

AIV: Conducting salt / solvent

The Active anode material may generally be 5-20% by weight of conducting salt and / or aprotic solvents include the conductivity promote. Useful conductive salts and solvents are in the "Handbook of Battery Materials ", I.O. Besenhard, VCH Weinheim, 1999, p. 462/463 and Chap. 7.2.

In a preferred embodiment the method according to the invention are used e.g. Conducting salts and / or solvents preferably used micro-encapsulated, but not in other embodiments must be the case. The microencapsulation is e.g. in "Ullmann's Industrial Chemistry" Vol. A 16, VCH Weinheim, 1990, p. 575.

Conducting salts used with particular preference are lithium organoborates, such as lithium oxalato borates, or LiPF ₆ . The conductive salts may preferably be used in combination with other additives such as MgO, Al ₂ O ₃ , SiO ₂ or silicates.

Especially preferred solvents are aprotic solvents, such as alkyl carbonates or glycol ethers or perfluoroethers, such as under AIII, which are used as flame retardants.

• a. Die Komponenten AI bis AIV werden mit einer Polymerdispersion als Bindemittel homogenisiert, um die Elektrodenmasse als eine einphasige Suspension zu erzeugen. Diese einphasige Suspension wird anschließend als homogene Beschichtungsschicht auf den Ableiter z.B. mit einem kontinuierlichen oder diskontinuierlichen Beschichtungsverfahren aufgebracht, getrocknet und auf die gewünschte Dicke gebracht. Vorzugsweise geschieht dies durch Kalandrieren. Die Dicke der erhaltenen Schicht ist bevorzugt 10 – 50 μm, bevorzugter 20 – 30 μm. Die als Bindemittel eingesetzte Polymerdispersion kann eine Primär- oder Sekundärdispersion sein. In einer Primärdispersion werden z.B. Monomere durch Emulsions-, Dispersions- oder Suspensionspolymerisation unter Zusatz von Dispergierhilfsmitteln polymerisiert. In einer Sekundärdispersion werden z.B. Polymere unter Zusatz von Dispergierhilfsmitteln dispergiert (nachträgliche Dispersion). Geeignete Verfahren hierfür finden sich z.B. in H.G. Elias, Makromoleküle, Band 2, S. 741 [1992], Hüttig & Wepf Verlag, Basel. Als bevorzugte Bindemittel werden solche auf Basis von Fluorpolymeren oder Polyolefinen basierend auf Ethylen, Propylen, Isobuten, Buten, Butadien und/oder Isopren als Mono- oder Copolymerisate, ggf. mit anderen ungesättigten Comonomeren eingesetzt. Weiter bevorzugt eingesetzte Bindemittel beinhalten Terpolymere auf Basis von Polyvinylidenfluorid (PVDF), Hexafluorpropylen (HFP) und einem Perfluoralkoxyether. Im Gegensatz zu den bekannten Verfahren wird erfindungsgemäß nicht nur Ruß mit einem Latexadditiv homogenisiert, sondern das gesamte Anodenmaterial einschließlich verschiedener Zusätze und ggf. der Leitsalze vermischt und so lange homogenisiert, bis es als eine einphasige Suspension vorliegt, die auf den Ableiter aufgebracht wird. Dadurch wird eine homogene Elektrodenmassenschicht auf den Ableiter ausgebildet, die hervorragende elektrochemische und physikalische Eigenschaften, wie eine hohe Bruchfestigkeit und eine gute Haftung der Elektrodenmasse auf dem Ableiter gewährleistet.
• b. Parallel zu dem vorher unter a. erwähnten Verfahren, kann die jeweilige Elektrodenmasse durch Extrusionsbeschichtung auf den Elektrodenableiter aufgetragen werden – z.B. das Anodenmaterial auf die Cu-Folie (als Ableiter). Hierbei werden die Komponenten AI, AII, AIII und AIV gemischt und im Extruder bei Temperaturen von 85 – 130°C, vorzugsweise bei 90 – 110°C gemischt und als Folie entsprechend der US 1996000653174 bzw. DE 101 18 639.8 extrudiert. Die bevorzugt Weiterverarbeitung der Anode und das Kombinieren mit Separator und Kathode zum Trilaminat und später zur gebrauchsfertigen Batterie wird im Folgenden dargestellt.
• c. Sogenannte Flüssigbeschichtung: In Polymerbinder-Lösungen werden aktive Massen dispergiert. Die Komponenten (Binder) AII werden in Lösungsmitteln, z.B. N-Methylpyrrolidon (NMP) oder Aceton gelöst (5 – 15%ige Lösungen) und anschließend das aktive Anodenmaterial AI zugesetzt und dispergiert. Diese Dispersion wird kontinuierlich aufgetragen, getrocknet und kalandriert. Vor dem Zusammenbau mit Separator und Kathode werden die Flammenhemmer sowie die Leitsalze und Lösungsmittel für die Leitsalze zugefügt, z.B. entsprechend dem in DE 101 34 057 A1 beschriebenen Verfahren.

The components AI to AIV listed above are intimately mixed and then preferably processed according to at least one of the following alternatives ac:

• a. The components AI to AIV are homogenized with a polymer dispersion as a binder to produce the electrode composition as a single-phase suspension. This single-phase suspension is then applied as a homogeneous coating layer on the arrester, for example by a continuous or discontinuous coating method, dried and brought to the desired thickness. Preferably, this is done by calendering. The thickness of the obtained layer is preferably 10 to 50 μm, more preferably 20 to 30 μm. The polymer dispersion used as a binder may be a primary or secondary dispersion. In a primary dispersion, for example, monomers are polymerized by emulsion, dispersion or suspension polymerization with the addition of dispersing aids. In a secondary dispersion, for example, polymers are dispersed with the addition of dispersing aids (subsequent dispersion). Suitable methods for this can be found, for example, in HG Elias, Makromolekule, Volume 2, p. 741 [1992], Hüttig & Wepf Verlag, Basel. Preferred binders are those based on fluoropolymers or polyolefins based on ethylene, propylene, isobutene, butene, butadiene and / or isoprene used as mono- or copolymers, optionally with other unsaturated comonomers. Further preferred binders include terpolymers based on polyvinylidene fluoride (PVDF), hexafluoropropylene (HFP) and a perfluoroalkoxy ether. In contrast to the known methods, according to the invention not only carbon black is homogenized with a latex additive, but the entire anode material including various additives and possibly the conductive salts mixed and homogenized until it is present as a single-phase suspension, which is applied to the arrester. As a result, a homogeneous electrode mass layer is formed on the arrester, which ensures excellent electrochemical and physical properties, such as a high breaking strength and good adhesion of the electrode mass on the arrester.
• b. Parallel to the previously under a. mentioned method, the respective electrode material can be applied by extrusion coating on the electrode conductor - for example, the anode material on the Cu film (as a conductor). Here, the components are mixed AI, AII, AIII and AIV and mixed in the extruder at temperatures of 85-130 ° C, preferably at 90-110 ° C and as a film according to the US 1996000653174 respectively. DE 101 18 639.8 extruded. The preferred further processing of the anode and the combination with separator and cathode to the trilaminate and later to the ready-to-use battery is shown below.
• c. So-called liquid coating: In polymer binder solutions, active materials are dispersed. The components (binders) AII are dissolved in solvents, for example N-methylpyrrolidone (NMP) or acetone (5-15% strength solutions), and then the active anode material AI is added and dispersed. This dispersion is applied continuously, dried and calendered. Prior to assembly with separator and cathode, the flame retardants and the conductive salts and solvents for the conductive salts are added, eg according to the in DE 101 34 057 A1 described method.

For the anode conductor it is preferred to use Cu foil, in particular with a thickness of 10-20 μm, e.g. those of Gould-Eichstetten. The arrester can be different have geometric shapes or designs, but are flat arresters preferably, e.g. the shape of foils, ribbons, a Möbius' band, cylinders, Balls, tubes, Nets or wires can have.

The arrester for the anode is preferably used ungeprimert. However, for improved conductivity, prior to application of the electrode mass layer to the arrester, a primer layer may additionally be applied. In particular, the primer layer may comprise graphite, carbon black, carbon black, Sn powder, a borate, a silicate, a conductive polymer, or a combination thereof. The proportion of carbon black or Sn may be, for example, 25-40% by weight, based on the primer. Particularly preferred primer combinations are, for example, graphite / Li-borate, conductive carbon black / Li-borate, carbon black / Dyneon THV 220 ^D® , Sn powder / Dyneon THV 220 ^D® . The primer can be applied in particular by liquid or spray coating with subsequent drying. The thickness of the primer is preferably 1-5 microns.

2nd preferred embodiment

In this embodiment a preferred method of manufacturing a cathode is described, wherein the electrode material mixture e.g. contain the following components can:

KI: active cathode material

For the cathode material, which is used for example in the form of powders or defined nanoparticles, preferably Li-intercalatable metal oxides can be used. In particular, oxi are suitable de of heavy metals of higher valence states selected from Mn, Ni, Co, Ti, W, Mo, Cr, and the like, for the cathode material. The active cathode material may be used in an amount of, for example, 50 to 90% by weight, based on the total electrode mass.

KII: Additions

Further, optional additives, eg, at 1-10 wt.%, Based on the total electrode mass, may be included in the cathode material. Preferred additives are polymers, such as polyvinylpyrrolidone and / or copolymers, fluoroelastomers and especially terpolymers thereof, and inorganic additives such as MgO, Al ₂ O ₃ , SiO ₂ or other silicates or borates are suitable.

KIII: flame retardant on Base of perfluoroether

The Cathode Blend may contain the flame retardants described under AIII.

KIV: Conducting salt / solvent

The proportion of conductive salts and / or aprotic solvents is, for example 5 to 20 wt .-%, which may be selected according to AIV. For the cathode material conductive salts are preferably used in combination with additives such as MgO, Al ₂ O ₃ , SiO ₂ or silicates, such as permutites, vermiculite or the like.

Also here is a microencapsulation of the components under KIV, accordingly AIV, the preferred form of use, with unencapsulated as needed Components can be used.

For the cathode conductor, a primed Al foil is preferably used in a thickness of 10-20 μm. For example, the primer layer may include graphite, carbon black, carbon black, Sn powder, a silicate, a borate, a conductive polymer, or a combination thereof to improve conductivity. The proportion of carbon black or Sn is preferably 25-40% by weight, based on the total weight of the primer. Particularly preferred primer combinations are, for example, graphite / Li-borate, conductive carbon black / Li-borate, carbon black / Dyneon THV 220 ^D® , Sn powder / Dyneon THV 220 ^D® . The primer may be applied by liquid or spray coating followed by drying. The thickness of the primer is preferably 1 - 5 microns.

The Manufacturing process for the cathodes according to the invention can be analogous to the method for the Anode done by the components KI to KIV intimately mixed and then homogenized after addition of the polymer dispersion until a single-phase suspension is present.

The single-phase suspension of the cathode mass is as in the manufacturing process for the Anodes are applied to the arrester or the primed arrester, dried and then to a thickness of preferably 10 - 50 microns, more preferably 30-40 μm, preferably by calendering, brought.

3rd preferred embodiment

In this embodiment becomes a high energy lithium polymer battery described with anode, cathode and a separator. The anode and / or Cathode is preferred according to the in the embodiments 1 and 2 described method. But it can also be any other manufacturing processes for Electrodes are used as long as at least one electrode mass as a single-phase suspension as electrode mass layer on the arrester or the primed conductor is applied.

Further embodiments are analogous as for the anodes also as extrusion coating (according to b) or as liquid coating (corresponding to c) for the cathodes possible.

The Battery also includes one to separate the anode from the cathode Separator, which is placed between the two electrodes.

The separator may, in particular of perforated polymer films or webs of PP (polypropylene) Celgard ^® or the like exist. It may also consist of extruded films, which may consist of swellable polymers which are already filled with electrolyte and optionally contain inorganic fillers.

The preparation of the separator is advantageously carried out by mixing the individual components. Before Constrained conditions are temperatures of 25 ° C to 160 ° C, eg in a Voith mixer. A particular preferred component mixture for the separator consists of the following components: 15% by weight Kynar ^® in 2801, 15% by weight Dyneon THV ^120® , 5% by weight Styroflex® ^® 10% by weight MgO, and 55% by weight aprotic solvents and liquid, flame retardant fluorine compounds with boiling points of 30 to 250 ° C.

The Mixture can after intensive stirring at 150 ° C heated then discharged and granulated. Modifications of the procedure are possible at any time to the knowledge of the person skilled in the art.

The granulated mixture is then fed to an extruder according to this specific embodiment and added via a metering pump (continuously) with 55 wt .-% of a 1 molar LiPF ₆ solution in ethylene carbonate / diethyl carbonate (1: 1), at an extrusion temperature of 105 ° C. mixed and discharged at an outlet temperature of 90 ° C at the slot die with a width of 150 mm and a thickness of 30 microns. The resulting Separatorfolie is wound in batch processes (eg with insulating paper as an intermediate layer) and fed in continuous processes directly to further processing, ie coating with anode or cathode masses.

However, a separator without conducting salt can also be used as the separator. Its preparation is preferably carried out as described above, but without Leitsalzzusatz (eg LiPF ₆ ). Only the aprotic solvents (ethylene carbonate / diethyl carbonate 1: 1) are incorporated via the metering pump in the extruder into the polymer mixture, advantageously together with MgO. The amount of aprotic solvents may be, for example, 55% by weight (based on the total separator mass). Also in this case, a Separatorfolie having a width, for example, of 150 mm and a thickness of, for example, 25 microns can be obtained.

In The following examples give details of the process according to the invention and the electrodes obtained thereby. At the specified Parts are parts by weight.

example 1

manufacturing an anode

80 parts of synthetic graphite MCMB ^® 26 and 2 parts of Sn powder (particle diameter of 2 to 10 microns) are mixed with 10 parts of Li-oxalatoborate and 18 parts of a mixture of ethylene / propylene carbonate (1: 1) was added and ml with stirring in 200 of a 10% solution of Dyneon THV ^® 220D in FC (a perfluorinated alkane) entered 84 ^®. Subsequently, this mixture is homogenized at room temperature for about 20 minutes, for example by means of an Ultraturrax at 1500 - 2000 U / min, until the component mixture is present as a single-phase suspension. Thereafter, the homogeneous electrode mass is applied by means of a roller or a Pastiermaschine on Cu film (12 microns, unprimed). The remaining coating layer has a thickness of 35-40 μm. By subsequent calendering at 60-70 ° C, a homogeneous coating with a thickness of 20-32 microns is set.

Example 2

manufacturing a cathode

According to the Example 1, 95 parts of Li-Co oxide interkalierbares with 2 parts of lithium acetylacetonate and 5 parts of Luviskol K90 ^® intensively mixed, admixed with 10 parts of Li-oxalatoborate, in 50 ml of a 1: 1 mixture of ethylene carbonate / propylene carbonate also microencapsulated added, in 50 ml of a 10% solution of Dyneon THV 220D ^® in Novec HFE 7500 ^® (trifluoromethyl-3-ethoxidodecafluorhexan) was added and while stirring with a dissolver for 30 minutes at 2000 rev / min and room temperature homogenised , The resulting single-phase suspension is applied to a primed Al foil with a pasting machine and then calendered at 60-70.degree. The layer thickness on the 18 μm thick Al foil is 40-45 μm.

Examples 3 to 6

Corresponding Examples 1 and 2 are blends with those in the following Table 1 listed Components prepared after addition of a polymer dispersion of the invention be homogenized to a single phase suspension.

Becomes under standard conditions, i. according to the two usual coating methods When working, the anode and cathode masses (i.e., more intercalatable Carbon or intercalatable heavy metal oxides) with polymer binders in a solvent, e.g. N-methylpyrrolidone (NMP), added, the mixture pasted and then on the arrester foil painted. After that, the solvent needs (NMP: bp 81-82 ° C, 10 mm) by thermal treatment down to residual amounts of smaller 0.5%, otherwise the NMP interferes.

Of the contains remaining film only the active electrode masses and polymer binders, i. no aprotic solvent and no conductive salt. These must later added become.

Becomes By contrast, by means of conventional Extrusion coating, e.g. according to WO 01/82403, worked that way also none of the above-described conductive salts is incorporated, otherwise a destruction of the Conducting salt takes place. Thus, here also the conductive salt in retrospect the electrode mass is inserted.

Comparative Examples

LiOB

= Li-Oxalatoborat

EC

= Ethylencarbonat

PC

= Propylencarbonat

DEC

= Diethylencarbonat

DI

= Dyneon (Fluorelastomer, Terpolymer) Schichtdicke = nach dem Kalandrieren

Lösung*

= 10%-ige Lösung NOVEC^TMFluorether im jeweiligen Lösungsmittel.

According to Examples 3 to 6, comparative examples were prepared which differed from the examples according to the invention in that they did not contain any flame retardants. Table 1

LiOB

= Li-oxalato borate

EC

= Ethylene carbonate

PC

= Propylene carbonate

DEC

= Diethylene carbonate

DI

= Dyneon (fluoroelastomer, terpolymer) layer thickness = after calendering

Solution*

= 10% solution of NOVEC ^TM fluoroether in the respective solvent.

The electrodes produced by the process according to the invention also show significant mechanical advantages in addition to the electrochemical advantages. Thus, the electrodes are unbreakable and easy to wind, such as a tight mandrel (Ø 5 mm). In addition, the electrodes have excellent adhesion of the electrode masses on the arrester, which is retained even after loading and unloading. This good adhesion of the homogeneous electrode mass layer also causes no infiltration of solvent or electrolyte occurs. It also prevents the occurrence of corrosion effects or the formation of local elements. The electrodes and the batteries produced with Celgard VECA 114 ^® as separator have a good shelf life and are hardly subject to fading (<2%), whereby a high energy density of eg greater than 120 Wh / kg is achieved.

The above cells (according to the examples 3-6) by combining anode + separator + cathode into a trilaminate together and wrapped and subjected to the previously described safety test.

manufacturing a winding cell

The composite system described above was on a winding machine (Ø 7.5 cm) wound. The arrester foils were contacted by laser welding and provided with Ableitscheiben at each pole of the battery. After that the entire system was wrapped in a shrink wrap.

Battery test load / unload

The wound cells prepared according to Examples 3-6 were formed and charged in a 3-step process with a current of 0.15 mA / m ² galvanostatically at 1.5 V, 2.8 V, 4.2 V and then potentiostatic at 4.2 V. For this purpose, a charging program and devices of the company Digatron (Aachen) was used. The discharge was also carried out with a current of 0.15 mA / m ² up to a discharge voltage of 2.8V.

The measured discharge capacity was 36-40 Ah and fading of about 2-2.5% was detected after 200 cycles (at temperatures up to 60 ° C).

safety tests

1) Overcharge protection

3) Nageltest (Nagel 3mmØ, 30 kg Gewicht)

4) Thermische* Stabilität

The cells (corresponding to Examples 3-6) were evaluated for resistance to degradation upon overcharging. For this purpose, the respective fully charged cell with constant current / constant voltage (constant voltage) at 4.2 V for 1 h with 1 C (constant) loaded, then it was switched off and maintained. It turns out that the cells of the comparative examples decomposed spontaneously within 30-40 seconds after the transfer process. In contrast, the cells according to the invention showed no decomposition after the transfer process and a waiting time of up to 24 h. 2) Short circuit: External short * (room temperature - 40 ° C)

3) nail test (nail 3mmØ, 30 kg weight)

4) Thermal * Stability

As already under point 1), the systems according to the invention passed the tests while the cells of the comparative examples decompose and develop of smoke or flames, i. the cells of the Comparative examples were sufficient not the test requirements.

Claims (42)

flame-retardant High energy lithium polymer cell, with the anode and cathode respectively a trap and an active electrode mass having at least one flame-retardant fluorine compound and a binder. flame-retardant The high energy lithium polymer cell of claim 1, wherein the flame retardant fluoro compound a perfluoroalkane and / or fluoroalkyl ether. A flame retarded high energy lithium polymer cell according to claim 2, wherein the perfluoroalkane is selected from perfluoroalkyl, cycloalkyl and / or aryl compounds with C ₂ -C ₁₀ . The flame retarded high energy lithium polymer cell of claim 2, wherein the fluoroalkyl ether comprises at least one perfluoroalkoxy group ROR ₁ , wherein R ₁ = CH ₃ , C ₂ H ₅ , C ₃ H ₇ , C ₄ H ₉ and R = perfluoroalkyl with C ₂ - C is ₁₀ . A flame-retardant high energy lithium polymer cell according to claim 4, wherein R = perfluoroalkyl with C ₂ -C ₆ . flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the flame-retardant fluorine compound has a boiling point of 30 up to 250 ° C and a vapor pressure of 0.01 to 85 k / Pa, flame-retardant The high energy lithium polymer cell of claim 6, wherein the flame retardant fluorine compound a boiling point of 30 to 130 ° C Has. flame-retardant The high energy lithium polymer cell of claim 6, wherein the flame retardant fluorine compound has a vapor pressure of 3 to 45k / Pa. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the flame retardant fluorine compound has a molecular weight of up to 900. flame-retardant The high energy lithium polymer cell of claim 9, wherein the flame retardant fluorine compound has a molecular weight of 250 to 650. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the flame retardant fluorine compound in amounts of 5-45 wt .-% based is contained on the electrode mass. flame-retardant High energy lithium polymer cell according to one of the preceding Claim 5, wherein the flame retardant fluorine compound in amounts of 10-25 wt .-% based on the electrode mass is included. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the binder is selected is from fluoropolymers, polyolefins, based on ethylene, propylene, Isobutene, butene, styrene butadiene and / or isoprene as mono- or Copolymers, and optionally other unsaturated comonomers. flame-retardant The high energy lithium polymer cell of claim 13, wherein the binder a terpolymer based on polyvinylidene fluoride, hexafluoropropylene and a perfluoroalkoxyether. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the binder is contained as a polymer dispersion. flame-retardant The high energy lithium polymer cell of claim 15, wherein the polymer dispersion a primary or secondary dispersion based on water or other auxiliary fluids or media. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the active electrode material for the anode is Li-intercalatable Carbon in the form of powders or fibers. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the active electrode material for the cathode with a Liinterkalationsfähiges oxide of a metal with a higher one Valence, selected of Mn, Ti, Co, Ni, W, Mo and Cr. flame-retardant The high energy lithium polymer cell of claim 18, wherein said Li intercalatable oxide a metal in the form of powders or nanoparticles. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the active electrode material at 50-80 wt%, based on the entire electrode mass, is included. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein As Leitsalz at least one Li salt is used. Flame-retardant high-energy lithium polymer cell according to claim 21, wherein the conductive salt used is Li organoborate and / or LiPF ₆ . flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein as a solvent aprotic solvents, selected from alkylcarbonates, glycol ethers and perfluoroethers are. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the conductive salts and / or aprotic solvents microencapsulated available. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the conductive salts and / or solvents with 5 to 20 wt .-%, based on the electrode mass included are. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein Contain polymers such as polyvinylpyrrolidone or fluoroelastomers are. A flame retarded high energy lithium polymer cell according to any one of the preceding claims, wherein additives selected from MgO, Al ₂ O ₃ , SiO ₂ and silicates are included. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the applied primer layer comprises graphite, carbon black, conductive carbon black, Sn powder, a Li borate, a silicate conductive polymer or a combination thereof. flame-retardant High energy lithium polymer cell according to one of the preceding Claims, wherein the thickness of the calendered layer of the electrode mass is 10 to 50 μm. A method of making flame retarded high energy lithium polymer cells, the anode and cathode each comprising a trap and an active electrode mass, comprising the steps of: (i) preparing an electrode material mixture by mixing Li-intercalatable active electrode material, conductive salt , Solvents and at least one flame retardant fluorine compound; (ii) mixing the electrode material mixture with a binder; (iii) homogenizing the entire mixture until the electrode mass is present as a single-phase suspension; (iv) applying the active electrode material as a homogeneous coating on the arrester; (v) adjusting the electrode mass to a desired layer thickness. The method of claim 30, wherein a flame retardant Fluorine compound as in claims 2 to 10 defined is used. Method according to one of the preceding claims, wherein the flame retardant fluorine compound in amounts of 10-25 wt .-% based is added to the electrode mass. Method according to one of the preceding claims, wherein the binder is used as a polymer dispersion. Method according to one of the preceding claims, wherein the polymer dispersion as a primary or secondary dispersion on watery Base or other auxiliary fluids or media is used. Method according to one of the preceding claims, wherein the active electrode material at 50-80 wt%, based on the entire electrode mass is used. Method according to one of the preceding claims, wherein the conductive salts and / or aprotic solvents microencapsulated available. Method according to one of the preceding claims, wherein the conductive salts and / or solvents with 5 to 20 wt .-%, based on the electrode composition used become. Method according to one of the preceding claims, wherein the single-phase suspension of the electrode mass continuously or is applied discontinuously to the arrester. Method according to one of the preceding claims, wherein before the deposition of the electrode on the arrester, in particular for the Cathode, a primer layer is applied as an intermediate layer. Method according to one of the preceding claims, wherein the application of the primer layer by means of liquid or spray coating takes place. Method according to one of the preceding claims, wherein the cell is a cell according to any one of claims 1 to 29. Method for producing a high energy lithium polymer battery, comprising an anode, a cathode and an intermediate one Separator, according to the method A cell produced according to any one of the preceding claims Composite system is combined, and housed in a battery and is poled.