Electrode binder composition for lithium-ion energy storage devices

Abstract

The present invention provides a cathode binder formulation that enables the production of a cathode that has balanced binding force and cathode slurry stability, and can be easily processed. [Solution] A binder for nanosized lithium phosphoolivine cathodes comprising a fluoropolymer composition, wherein the composition comprises at least one thermoplastic fluoropolymer containing at least one functional monomer, and is tested at room temperature by a Brookfield viscometer with 5% by weight solids in NMP at 10s -1 A binder having a solution viscosity of 0.3 Pa.s to 1 Pa.s is provided.

Description

[Technical Field]

[0001] This invention generally relates to the field of electrical energy storage in lithium-ion batteries. More specifically, the invention relates to a binder for the positive electrode of a lithium-ion battery, a method for preparing the electrode, and its use in a lithium-ion battery. Another subject of the invention is a lithium-ion battery manufactured by incorporating this electrode material. [Background technology]

[0002] The basic cell of a lithium-ion battery or lithium battery generally comprises a lithium metal or carbon-based anode (during discharge) and a cathode (similarly during discharge) generally made of a metal oxide type lithium-intercalated compound, with an electrolyte that conducts lithium ions inserted between them.

[0003] The cathode or anode generally includes at least one current collector on which a composite material is deposited, comprising one or more polymers, such as polyvinylidene fluoride (PVDF), or aqueous polymers of the carboxymethylcellulose type or styrene / butadiene latex, which act as a binder and are generally functionalized or unfunctionalized fluoropolymers, and one or more electronically conductive additives, which are generally allotropes of carbon, acting as a binder and generally functionalized or unfunctionalized fluoropolymers, in addition to one or more "active" substances that are generally active to exhibit electrochemical activity toward lithium.

[0004] Conventional active materials in the negative electrode are generally lithium metal, graphite, silicon / carbon composite materials, silicon, and CF with x = 0 to 1. X Fluorographite and LiTi5O 12 It is a type of titanate.

[0005] Conventional active materials used in cathodes are generally LiMO2 type, LiMPO4 type, Li2MPO3F type, Li2MSiO4 type (where M is Co, Ni, Mn, Fe, or a combination thereof), LiMn2O4 type, or S8 type.

[0006] Among these materials, lithium iron phosphate (LiFePO4 or LFP) with an olivine structure has a high theoretical capacity (170 mAhg). -1 Due to its high safety and economic benefits, LiFePO4 is attracting attention as a potential cathode material for lithium-ion batteries. However, LiFePO4 has poor conductivity and a low lithium-ion diffusion coefficient. To address these problems, several methods have been proposed, including morphological control, surface coating of additional layers, and the use of conductive additives.

[0007] Nanosizing is a method to improve the rate performance of LFP cathodes by shortening the lithium ion migration length. A binder with higher bonding strength is required to maintain the cathode's bonding level to the aluminum foil because nanosized LFPs have a large surface area. Furthermore, the slurry viscosity of nanosized LFPs is very high, and they can easily physically gel or increase in viscosity during storage.

[0008] Reference US2017 / 373319 describes a conductive paste for lithium-ion battery positive electrodes that has a viscosity that allows for easy application while suppressing viscosity increases and gelation. The conductive paste comprises a dispersion resin (A) containing a polycyclic aromatic hydrocarbon group-containing resin (A1) and a polyvinyl alcohol resin (A2), polyvinylidene fluoride (B), conductive carbon (C), and a solvent (D) containing a dehydrating agent (E). This combination of components (A) to (D) and the dehydrating agent (E) presumably suppresses polymerization of polyvinylidene fluoride molecules, and this suppression inhibits viscosity increases and gelation of the conductive paste or composite paste for lithium-ion battery positive electrodes.

[0009] A cathode binder formulation is needed that provides balanced binding force and cathode slurry stability, enabling the production of easily processable cathodes.

[0010] It was found that by combining a specific range of functional groups in a fluoride binder with a specific viscosity in the binder formulation, the binding strength is improved compared to non-functionalized binders, while good slurry processability is maintained in nano-sized phospho-olivine cathode formulations. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] U.S. Patent Application Publication No. 2017 / 373319 [Overview of the project] [Problems that the invention aims to solve]

[0012] The first object of the present invention is a binder for nanosized phospho-olivine cathodes comprising a fluoropolymer composition, wherein the composition comprises at least one thermoplastic fluoropolymer containing at least one functional monomer, and is tested at room temperature (25°C) by a Brookfield viscometer with 5% by weight solids in NMP for 10 sq. -1 The objective is to provide a binder for nano-sized phospho-olivine cathodes having a solution viscosity of 0.3 Pa.s to 1 Pa.s.

[0013] Another object of the present invention is to provide a lithium-ion battery cathode material comprising at least one electronically conductive additive, nanosized phosphoolivine as an electrode active material capable of reversibly forming an insertion compound with lithium, and a polymer binder, wherein the binder is made of a fluoropolymer composition according to the present invention.

[0014] Another object of the present invention is a method for preparing the above-mentioned electrode composite material, i) Preparation of a slurry by mixing the following components in a solvent or a mixture of solvents: -Electronically conductive additives; - A polymer binder according to the present invention, - Nano-sized phospho-olivine as the electrode active material, ii) Preparation of a film starting from the slurry prepared in (i), iii) Coating the film on a current collector and evaporating the solvent, is a method for preparing the above electrode composite material.

[0015] In addition, the subject of the present invention is a lithium ion battery comprising the material.

[0016] According to the present invention, it is possible to meet the above needs. In particular, the present invention provides a binder formulation having improved binding strength that can maintain good slurry processability in nano-sized phospho-olivine cathodes.

Embodiments for Carrying Out the Invention

[0017] In the following description, without limiting the present invention, it will be described in more detail. Unless otherwise specified, the percentages in this application are weight percentages.

[0018] According to a first aspect, the present invention is a binder for a nano-sized lithium phospho-olivine cathode comprising a fluoropolymer composition, the composition comprising at least one thermoplastic fluoropolymer comprising at least one functional monomer, and having a solution viscosity of from 0.3 Pa·s to 1 Pa·s at 10 s -1 at 5% solids in NMP when tested with a Brookfield viscometer at room temperature, for a nano-sized phospho-olivine cathode.

[0019] Fluorinated vinyl monomer fluoropolymers include vinylidene fluoride (VDF), tetrafluoroethylene (TFE), trifluoroethylene (TrFE), chlorotrifluoroethylene (CTFE), hexafluoropropene (HFP), vinyl fluoride (VF), hexafluoroisobutylene (HFIB), perfluorobutylethylene (PFBE), pentafluoropropene, 3,3,3-trifluoro-1-propene, 2-trifluoromethyl-3,3,3-trifluoropropene, and 2,3,3,3-teto The material contains vinyl monomers selected from the group comprising lafluoropropene, perfluoromethyl ether (PMVE), perfluoroethyl vinyl ether (PEVE), perfluoropropyl vinyl ether (PPVE), perfluorobutyl vinyl ether (PBVE), long-chain alkyl perfluorinated vinyl ethers, vinyl fluorinated ethers containing dioxol fluoride, partially fluorinated or perfluorinated alphaolefins of C4 or more, partially fluorinated or perfluorinated cyclic alkenes of C3 or more, and combinations thereof.

[0020] According to one embodiment, the fluoropolymer is selected from vinylidene fluoride copolymer and poly(vinylidene fluoride).

[0021] The term "PVDF" as used herein includes vinylidene fluoride (VDF) homopolymer or copolymers of VDF and at least one other comonomer, wherein VDF accounts for at least 50 mol%. Comonomers polymerizable with VDF include vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene (CTFE), 1,2-difluoroethylene, tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoro(alkyl vinyl) ethers, such as perfluoro(methyl vinyl) ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE), or perfluoro(propyl vinyl) ether (PPVE), perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole) (PDD), products of the formula CF2=CFOCF2CF(CF3)OCF2CF2X (wherein X is SO2F, CO2H, CH2OH, CH2OCN, or CH2OPO3H), products of the formula CF2=CFOCF2CF2SO2F, and F(CF2). n Products of CH2OCF=CF2 (wherein n is 1, 2, 3, 4, or 5), formula R1CH2OCF=CF2 (wherein R1 is hydrogen or F(CF2) z The product is (where z has a value of 1, 2, 3, or 4), and the formula is R3OCF=CH2 (where R3 is F(CF2) z The product is selected from perfluorobutylethylene (PFBE), fluoroethylene propylene (FEP), 3,3,3-trifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-1-propene, 2,3,3,3-tetrafluoropropene, i.e., HFO-1234yf, E-1,3,3,3-tetrafluoropropene, i.e., HFO-1234zeE, Z-1,3,3,3-tetrafluoropropene, i.e., HFO-1234zeZ, 1,1,2,3-tetrafluoropropene, i.e., HFO-1234yc, 1,2,3,3-tetrafluoropropene, i.e., HFO-1234ye, 1,1,3,3-tetrafluoropropene, i.e., HFO-1234zc, and chlorotetrafluoropropene, i.e., HCFO-1224.

[0022] The fluoropolymer composition comprises at least one thermoplastic fluoropolymer containing a vinyl fluoride monomer and at least another comonomer having a functional group selected from carboxyl, epoxy, carbonyl, or hydroxyl. According to one embodiment, the fluoropolymer comprises a unit having at least one of the following functional groups: carboxylic acid, carboxylic acid anhydride, carboxylic acid ester, epoxy group (such as glycidyl), amide group, alcohol group, carbonyl group, mercapto group, sulfide, oxazoline group, and phenol group.

[0023] The functional groups are introduced into the fluoropolymer by a chemical reaction, which can be grafting or copolymerization of the fluoropolymer with a compound having at least one of the functional groups, according to techniques well known to those skilled in the art.

[0024] According to one embodiment, the functional group is a chain-terminal functional group, which means that the functional group is located at the end of the fluoropolymer chain.

[0025] According to one embodiment, a monomer having a functional group is intercalated into a fluoropolymer chain.

[0026] According to one embodiment, the carboxylic acid functional group is a (meth)acrylic acid type hydrophilic group selected from acrylic acid, methacrylic acid, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxyethylhexyl (meth)acrylate.

[0027] According to one embodiment, the fluoropolymer composition excludes acrylic copolymers such as copolymers of methyl methacrylate and methacrylic acid.

[0028] According to one embodiment, the unit having a carboxylic acid functional group further comprises a heteroatom selected from oxygen, sulfur, nitrogen, and phosphorus.

[0029] When the fluoropolymer is functionalized, the content of the functional group is at least 0.01% by weight and at most 0.2% by weight based on the weight of the fluoropolymer composition.

[0030] According to one embodiment, the fluoropolymer composition is a blend comprising a high molecular weight fluoropolymer and a functionalized high molecular weight fluoropolymer.

[0031] The term "high molecular weight fluoropolymer" means a fluoropolymer having a melt viscosity of 2300 Pa·s or more at 232 °C under a shear of 100 s -1 The viscosity is measured at a shear rate of 100 s

[0032] at 232 °C using a capillary rheometer or a parallel plate rheometer in accordance with ASTM D3825 standard. Similar results can be obtained by two methods. -1 at 232 °C using a capillary rheometer or a parallel plate rheometer in accordance with ASTM D3825 standard. Similar results can be obtained by two methods.

[0033] According to one embodiment, the fluoropolymer composition consists of a functionalized high molecular weight fluoropolymer.

[0034] The PVDF used in this invention is generally prepared by means known in the art using aqueous free radical emulsion polymerization, although suspension, solution, and supercritical CO2 polymerization methods may also be used. In emulsion polymerization, deionized water, a water-soluble surfactant capable of emulsifying the reactant mass during polymerization, and an optional paraffin wax antifouling agent are added to the reactor. The mixture is stirred and deoxygenated. A predetermined amount of chain transfer agent CTA is then introduced into the reactor, the temperature of the reactor is raised to a desired level, and vinylidene fluoride (and optionally one or more comonomers) is supplied to the reactor. Once the initial supply of vinylidene fluoride has been introduced and the pressure in the reactor has reached a desired level, the initiator emulsion or solution is introduced to start the polymerization reaction. The reaction temperature can be varied depending on the properties of the initiator used, and methods for doing so will be known to those skilled in the art. Typically, the temperature is about 30°C to 150°C, preferably about 60°C to 120°C. Once the desired amount of polymer is reached in the reactor, the monomer supply is stopped, but the initiator supply is optionally continued to consume any remaining monomer. The residual gas (containing unreacted monomer) is discharged, and the latex is recovered from the reactor.

[0035] The surfactant used in polymerization can be any surfactant known in the art to be useful for PVDF emulsion polymerization, including overfluorinated, partially fluorinated, and non-fluorinated surfactants. Preferably, the PVDF emulsion of the present invention does not contain fluorescent surfactants, and no fluorescent surfactants are used in any part of the polymerization. Non-fluorinated surfactants useful for PVDF polymerization include, but are not limited to, 3-allyloxy-2-hydroxy-1-propanesulfonates, polyvinylphosphonic acid, polyacrylic acid, polyvinyl sulfonic acid and its salts, polyethylene glycol and / or polypropylene glycol and its block copolymers, alkylphosphonates, and siloxane-based surfactants, and can be both ionic and nonionic in nature.

[0036] PVDF polymerization generally produces latex having a solids content level of 10% to 60% by weight, preferably 10% to 50% by weight, and a weight-average particle size of less than 500 nm, preferably less than 400 nm, and more preferably less than 350 nm. The weight-average particle size is generally at least 20 nm, preferably at least 50 nm. Additional adhesion promoters may also be added to improve bonding properties and provide irreversible connectivity.

[0037] PVDF latex can be used in the present invention as a latex binder, or can be dried into a powder by means known in the art, such as spray drying, freeze-drying, solidification, and drum drying. The dried PVDF powder has an average particle size of 0.5 to 200 microns, preferably 1 to 100 microns, more preferably 2 to 50 microns, and most preferably 3 to 20 microns. The PVDF powder can be used after dispersion in water or dissolution in a solvent.

[0038] Functionalized fluorinated polymers react in an aqueous reaction medium. a) To form an aqueous emulsion comprising at least one initiator, a stabilizer, at least one vinyl fluoride monomer, and a hydrophilic monomer as defined above. b) Initiating the copolymerization of the at least one vinyl fluoride monomer and the hydrophilic monomer with stirring under heating and superatmospheric pressure. It can be prepared by a method including the following.

[0039] The polymerization reaction according to the present invention may be carried out by adding water (preferably deionized water), at least one vinyl fluoride monomer, at least one hydrophilic monomer as defined above, and optionally one or more surfactants, chain transfer agents and / or antifouling agents to the reactor. Air may be purged from the reactor before the introduction of monomers. Water is added to the reactor before the reactor reaches the desired starting temperature, although other materials may be added before or after the reactor reaches the temperature. At least one radical initiator is added to start and maintain the polymerization reaction. Further monomers may be optionally added to replenish the monomers consumed, and other materials may be optionally added during polymerization to maintain the reaction and control the properties of the final product.

[0040] Another object of the present invention is to provide a lithium-ion battery cathode material comprising at least one electronically conductive additive, nanosized phosphoolivine as an electrode active material capable of reversibly forming an insertion compound with lithium, and a polymer binder, wherein the binder is made of the above-mentioned fluoropolymer composition.

[0041] The term "phospho-olivine" active material refers to lithium iron phosphate LiFePO4 (LFP) and lithium iron manganese phosphate LiMn x Fe 1-x Includes PO4(LMFP), 0 <x<1である。

[0042] According to one embodiment, the phospho-olivine cathode material consists of lithium iron phosphate.

[0043] According to one embodiment, the phospho-olivine cathode material is lithium-iron-manganese phosphate (LiMn x Fe 1-x It consists of PO4(LMFP).

[0044] According to one embodiment, the phospho-olivine cathode material is LiFePO4 and LiMn x Fe 1-xIt consists of a blend with PO4, and the blend ratio varies from 0% to 100% by weight of each component.

[0045] In a preferred embodiment, the positive electrode material is a compound, a) At least one electronically conductive additive in an amount of 0.5 to 5% by weight, preferably 0.6 to 4% by weight, relative to the total weight of the cathode compound, b) The nanosized phosphoolivine as an electrode active material in an amount of 90 to 99% by weight relative to the total weight of the cathode formulation. c) The polymer binder in an amount ranging from 0.5% to 5% by weight relative to the total weight of the cathode formulation. It has a composition that includes [specific ingredient], and the total percentage of all ingredients equals 100%.

[0046] The electronically conductive additive is preferably selected from different allotropes of carbon or conductive organic polymers.

[0047] Nano-sized phosphoolivine is 15m 2 It has a BET specific surface area (SSA) greater than / g.

[0048] Another object of the present invention is a method for preparing the above-mentioned electrode composite material, i) Preparation of a slurry having a solid content of 40-80% by weight by mixing the following components in a solvent or a mixture of solvents: - At least one electronically conductive additive; - A polymer binder according to the present invention, -Nano-sized phosphoolivine as an electrode active material, ii) Preparation of a film starting from the slurry prepared in (i), iii) Coat the film onto the current collector and evaporate the solvent. This is a method for preparing the above-mentioned electrode composite material, including the above-mentioned elements.

[0049] The slurry can be obtained by any mechanical means, such as using a rotor stator or anchor agitator, or by ultrasonic dispersion and homogenization.

[0050] Preferably, the solvent is an organic solvent such as N-methylpyrrolidone (NMP), cyclopentanone, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc), or a combination thereof.

[0051] The suspension can be prepared in a single step or in two or three consecutive steps. When the suspension is prepared in two consecutive steps, one embodiment involves, in the first step, using mechanical means to prepare a dispersion containing the solvent and optionally all or part of the polymer binder, and then, in the second step, adding the other components of the composite material to this first dispersion. Subsequently, a film is obtained from the suspension at the end of the second step.

[0052] The metal support of the cathode (current collector) is generally made of aluminum. Evaporation of the solvent is generally carried out by heating at a temperature of 30°C to 150°C.

[0053] In addition, the subject of the present invention is a lithium-ion battery that incorporates the material. [Examples]

[0054] [Examples 1-10] <Method for manufacturing a cathode and the composition of a cathode> The electrodes were prepared by mixing nano-LFP, a binder, and a conductive agent (CA) with a solvent (N-methylpyrrolidone, NMP), and the solid content of the slurry varied from 40% to 60%. The blend formulations were LFP / binder / CA = 90-99 / 0.5-5 / 0.5-5.

[0055] Tests were conducted on various functional binders.

[0056] The results for binding strength (detachment value), slurry fluidity under low shear (representing free fluidity), and moderate shear (representing fluidity under forces such as casting or pumping) were used for evaluation.

[0057] The bonding strength was measured by a 180° peel test using an ASTM D903 at a speed of 50 mm / min on an INSTRON 5966 tensile machine. The slurry was tested in frequency sweep mode using an Anton Paar MCR302 with the following settings: 25°C, 0.1~100 Hz, 0.1% strain, and 120 seconds of immersion time. The dissipation coefficient tanδ can be calculated using the formula: tanδ = G'' / G', based on the storage modulus (G') and loss modulus (G''). If tanδ > 1, it is considered to be in a liquid-like state, and if tanδ < 1, it is considered to be in a solid-like state. The reference peel force is 30 N / m.

[0058] The following fluoride binders are used.

[0059] -FP1: 232℃ and 100s -1 A PVDF homopolymer having a melt viscosity exceeding 4000 Pa.s. -FP2: 232℃ and 100s -1 A carboxylic acid-functionalized PVDF homopolymer having a melt viscosity of 8500 Pa.s. -FP3: 232℃ and 100s -1 A copolymer of VDF and HFP having a melt viscosity of 3300 Pa·s. -FP4: 232℃ and 100s -1 A carboxylic acid-functionalized PVDF homopolymer having a melt viscosity of 7000 Pa·s. -FP5: 232℃ and 100s -1 A carboxylic acid-functionalized PVDF homopolymer having a melt viscosity of 6900 Pa.s. -Solef(registered trademark) 5130: 232℃ and 100s -1 A functionalized PVDF sold by Solvay, having a melt viscosity exceeding 2700 Pa.s.

[0060] The solution viscosities of the binder and blend are shown in Table 1 below.

[0061] [Table 1]

[0062] The results are shown in Table 2 below.

[0063] [Table 2]

Claims

1. A binder for nanosized lithium phosphoolivine cathodes comprising a fluoropolymer composition, wherein the composition comprises at least one thermoplastic fluoropolymer containing at least one functional monomer, and is tested at room temperature using a Brookfield viscometer with a solid content of 5% by weight in NMP and 10 s. －１ A binder having a solution viscosity of 0.3 Pa.s to 1 Pa.s.

2. The binder according to claim 1, wherein the thermoplastic fluoropolymer comprises a vinyl fluoride monomer and at least another comonomer having a functional group selected from carboxyl, epoxy, carbonyl, or hydroxyl.

3. The fluoropolymers include vinylidene fluoride (VDF), tetrafluoroethylene (TFE), trifluoroethylene (TrFE), chlorotrifluoroethylene (CTFE), hexafluoropropene (HFP), vinyl fluoride (VF), hexafluoroisobutylene (HFIB), perfluorobutylethylene (PFBE), pentafluoropropene, 3,3,3-trifluoro-1-propene, 2-trifluoromethyl-3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, and perfluoro A binder according to claim 1 or 2, comprising a vinyl fluoride monomer selected from the group comprising methyl ether (PMVE), perfluoroethyl vinyl ether (PEVE), perfluoropropyl vinyl ether (PPVE), perfluorobutyl vinyl ether (PBVE), long-chain alkyl perfluorinated vinyl ether, vinyl fluoride ether containing dioxole fluoride, partially fluorinated or perfluorinated alphaolefins of C4 or more, partially fluorinated or perfluorinated cyclic alkenes of C3 or more, and combinations thereof.

4. The fluoropolymer is selected from poly(vinylidene fluoride) homopolymers and copolymers of vinylidene fluoride and at least one other comonomer, wherein the copolymer has VDF accounting for at least 50 mol%, and the comonomer is vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene (CTFE), 1,2-difluoroethylene, tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoro(alkyl vinyl) ether, such as perfluoro(methyl vinyl) ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE) or perfluoro(propyl vinyl) ether (PPVE), perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole) (PDD), formula CF ２ =CFOCF ２ CF(CF ３ )OCF ２ CF ２ X (where X is SO ２ F, CO ２ H, CH ２ OH, CH ２ OCN or CH ２ OPO ３ H), product of formula CF ２ =CFOCF ２ CF ２ SO ２ F, product of formula F(CF ２ ) ｎ CH ２ OCF = CF ２ (where n is 1, 2, 3, 4 or 5), product of formula R1CH ２ OCF = CF ２ (where R1 is hydrogen or F(CF ２ ) ｚ and z has a value of 1, 2, 3 or 4), product of formula R3OCF = CH ２ (where R3 is F(CF ２ ) ｚ The product is (where z has a value of 1, 2, 3 or 4), or perfluorobutylethylene (PFBE), fluoroethylene propylene (FEP), 3,3,3-trifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-1-propene, 2,3,3,3-tetrafluoropropene i.e., HFO-1234yf, E-1,3,3,3-tetrafluoropropene i.e., HFO-1234zeE, Z- A binder according to any one of claims 1 to 3, selected from 1,3,3,3-tetrafluoropropene i.e., HFO-1234zeZ, 1,1,2,3-tetrafluoropropene i.e., HFO-1234yc, 1,2,3,3-tetrafluoropropene i.e., HFO-1234ye, 1,1,3,3-tetrafluoropropene i.e., HFO-1234zc, and chlorotetrafluoropropene i.e., HCFO-1224.

5. The binder according to any one of claims 1 to 4, wherein the proportion of functional groups in the functionalized fluoropolymer is at least 0.01% by weight and 0.2% by weight or less relative to the weight of the fluoropolymer composition.

6. A lithium-ion battery cathode material comprising at least one electronically conductive additive, nano-sized lithium iron phosphate as an electrode active material capable of reversibly forming an insertion compound with lithium, and a polymer binder, wherein the binder is comprised of the fluoropolymer composition described in any one of claims 1 to 5.

7. Nano-sized lithium-iron-manganese phosphate (LiMn) is an electrode active material capable of reversibly forming an insertion compound with at least one electronically conductive additive and lithium. ｘ Fe １－ｘ PO ４ A lithium-ion battery cathode material comprising (0 < x < 1) and a polymer binder, wherein the binder is a fluoropolymer composition according to any one of claims 1 to 5.

8. A lithium-ion battery cathode material comprising at least one electronically conductive additive, a blend of nanosized lithium iron phosphate and lithium iron-manganese phosphate as an electrode active material capable of reversibly forming an insertion compound with lithium, and a polymer binder, wherein the binder is comprised of the fluoropolymer composition described in any one of claims 1 to 5.

9. a) At least one electronically conductive additive in an amount ranging from 0.5 to 5% by weight relative to the total weight of the cathode compound, b) The nanosized phosphoolivine as an electrode active material in an amount of 90 to 99% by weight relative to the total weight of the cathode compound, c) The polymer binder in an amount of 0.5 to 5% by weight relative to the total weight of the cathode compound, Including that, the sum of all percentages equals 100%. A Li-ion cathode material according to any one of claims 6 to 8, having a compound composition.

10. The lithium-ion battery cathode material according to any one of claims 6 to 9, wherein the electronically conductive additive is selected from different allotropes of carbon or conductive organic polymers.

11. A method for preparing an electrode material according to any one of claims 6 to 10, i) Mix the following components in a solvent or a mixture of solvents to obtain a slurry with a solid content of 40 to 60% by weight: - Electronically conductive additives; - Polymer binder; - Nano-sized lithium phosphoolivine as an electrode active material, ii) Preparation of a film starting from the slurry prepared in (i), iii) Coating the film onto the current collector and evaporating the solvent, Methods that include...

12. The method according to claim 11, characterized in that the solvent is an organic solvent.

13. The method according to claim 11, characterized in that the organic solvent is selected from N-methylpyrrolidone, cyclopentanone, dimethylformamide, dimethyl sulfoxide, dimethylacetamide, and combinations thereof.

14. A Li-ion battery comprising the positive electrode material according to any one of claims 6 to 10.

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