Binder for dry coated electrodes

Abstract

The present invention generally relates to the field of electrical energy storage in lithium accumulators of the Li-ion type. More specifically, the present invention relates to a non-fibrillizable binder for dry-coated electrodes for Li-ion batteries. Another subject of the present invention is a manufacturing method for producing electrodes using said binder. The present invention also relates to a lithium-ion battery manufactured by incorporating said electrode.

Description

[Technical field]

[0001] The present invention relates generally to the field of electrical energy storage in lithium accumulators of the Li-ion type. More specifically, the invention relates to a non-fibrillizable binder for dry-coated electrodes for Li-ion batteries. Another subject of the invention is a manufacturing method for producing electrodes using said binder. The invention also relates to a lithium-ion battery manufactured by incorporating said electrode. [Background technology]

[0002] The basic cell of a Li-ion accumulator or lithium battery consists of an anode (when discharging), usually made of a lithium insertion compound of the metal oxide type such as LiMn2O4, LiCoO2 or LiNiO2, and a cathode (also when discharging), between which an electrolyte that conducts lithium ions is inserted.

[0003] Rechargeable or secondary cells have an advantage over primary (non-rechargeable) cells because the relevant chemical reactions that occur at the positive and negative electrodes of the battery are reversible. The electrodes of a secondary cell can be regenerated several times by applying an electric charge. Many advanced electrode systems have been developed to store the electric charge. At the same time, much effort has been put into the development of electrolytes that can improve the capacity of electrochemical cells.

[0004] For their part, the electrodes generally comprise at least one current collector on which is deposited, in the form of a film, a composite material consisting of the so-called active material (because it has electrochemical activity towards lithium), a polymer acting as a binder, one or more electronically conductive additives, generally carbon black or acetylene black, and optionally a surfactant.

[0005] Binders are counted among the so-called inactive components, since they do not directly contribute to the battery capacity. However, their important role in electrode processing and their significant impact on the electrochemical performance of the electrode have been widely described. The main relevant physical and chemical properties of binders are thermal stability, chemical and electrochemical stability, tensile strength (strong adhesion and cohesion), and flexibility. The main purpose of using binders is to form a stable network of the solid components of the electrode, i.e., active materials and conductive agents (cohesion). The binder must also ensure the adhesion (adhesion) between the composite electrode and the current collector.

[0006] Poly(vinylidene fluoride) (PVDF) is the most commonly used binder in lithium-ion batteries due to its excellent electrochemical stability, good binding ability, and high adhesion to electrode materials and current collectors. PVDF can only be dissolved in certain organic solvents, such as N-methylpyrrolidone (NMP), which is volatile, flammable, explosive, and highly toxic, leading to serious environmental concerns.

[0007] Compared to traditional wet suspension electrode manufacturing methods, dry (solvent-free) manufacturing processes are simpler. These processes eliminate the emission of volatile organic compounds and offer the possibility to manufacture electrodes with greater thickness (>120 μm) with higher energy density of the final energy storage device. The change in manufacturing technology has little effect on the active material of the electrode, but the polymer additives responsible for the mechanical integrity of the electrode must be adapted to the new manufacturing conditions.

[0008] Wang et al.'s publication (J. Electrochem. Soc. 2019 166(10):A2151-A2157) describes LiNi nanowires fabricated by a dry powder coating process. 0.33 Co 0.33 Mn 0.33The effect of the molecular weight of the PVDF binder on the electrochemical performance and mechanical integrity of O2(NMC) electrodes was investigated. It shows that after heating PVDF above its melting point, a thin PVDF layer can be formed on the NMC particle surface. The microstructure and porosity of the PVDF layer are highly dependent on the molecular weight of PVDF. As the molecular weight increases, the PVDF layer becomes more porous, improving the high-rate capacity without compromising the bond strength and long-term cycling performance of the electrode. However, these results require a thermal activation manufacturing method (baking at 200°C for 1 h), which increases the manufacturing cost of Li batteries.

[0009] There remains a need to develop new binder and electrode compositions for Li-ion batteries that are suitable for processing without the use of organic solvents. [Prior art documents] [Non-patent literature]

[0010] [Non-Patent Document 1] Wang et al., J. Electrochem. Soc. 2019 166(10):A2151-A2157 Summary of the Invention [Problem to be solved by the invention]

[0011] Accordingly, the present invention is directed to providing a binder for a dry coated electrode for a Li-ion battery. [Means for solving the problem]

[0012] It is a first object of the present invention to provide a non-fibrillable binder for dry coated electrodes, which binder consists of a fluoropolymer powder having a particle size distribution with a D50 of less than 10 μm and a D90 of less than 25 μm.

[0013] The present invention also aims to provide a dry-coated electrode for a Li-ion battery, comprising the binder.

[0014] The present invention also provides a method for producing a dry-coated electrode, comprising the steps of: - mixing active fillers, polymeric binders and conductive fillers using a process that provides an electrode formulation that can be applied to a metal substrate by a "solvent-free" process; - depositing said electrode formulation on a metal substrate by a dry process to obtain a Li-ion battery electrode; - consolidating said electrode by mechanical and / or thermomechanical treatment; The present invention relates to a method comprising the steps of:

[0015] Another object of the invention is a Li-ion secondary battery comprising a negative electrode, a positive electrode and a separator, at least one of the electrodes being as described above.

[0016] The present invention makes it possible to address the above needs. In particular, the present invention provides techniques that make it possible to: - ensuring the cohesion and mechanical integrity of the electrode and guaranteeing good filming or consolidation of the formulation, which can be difficult to achieve in solventless processes; - Generates adhesion on metal substrates; - ensuring homogeneity of the electrode composition across the thickness and width of the electrode; - ensuring homogeneity in electrode thickness and width; - reducing the overall binder content in the electrode (which is still higher for the known dry processes than for the standard slurry processes);

[0017] The advantage of this technique is that it improves the following properties of the electrode: homogeneity of the composition in thickness, cohesion, and adhesion on the metal substrate. It also allows a reduction in the proportion of binder required in the electrode, as well as a reduction in the temperature and duration of the heat treatment required to improve adhesion. [Brief description of the drawings]

[0018] [Figure 1]FIG. 1 shows the peel strength results of four cathodes, n° 2 and 4 containing a binder according to the invention. [Diagram 2] FIG. 2 shows the peel strength results of four anodes, n° 2 and 4 containing a binder according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The invention will now be explained in more detail in the following description.

[0020] Firstly, the present invention relates to a non-fibrillizable binder for dry coated electrodes, which consists of a fluoropolymer powder having a particle size distribution with a D50 of less than 10 μm, preferably less than 5 μm, and a D90 of less than 25 μm, preferably less than 15 μm.

[0021] According to various embodiments, the binder has the following characteristics, which may be combined where applicable:

[0022] Dv50 is the particle size at the 50th percentile (by volume) of the cumulative particle size distribution. This parameter can be determined by laser particle size distribution. This applies to all Dv50s listed in this specification.

[0023] D90 is the particle size at the 90th percentile (by volume) of the cumulative size distribution of particles. This parameter can be determined by laser particle size distribution. This applies to all Dv90s listed in this specification.

[0024] The term "fluoropolymer" means a polymer formed by polymerization of at least one fluoromonomer, and includes homopolymers, copolymers, terpolymers, and higher polymers that are thermoplastic. In certain embodiments of the present invention, the fluoropolymer contains at least 50 mole percent of one or more fluoromonomers in polymerized form.

[0025] "Thermoplastic" is understood herein to mean a non-elastic polymer. An elastic polymer is defined as a polymer that can be stretched to twice its original length at ambient temperature, as indicated by ASTM Special Technical Publication No. 184, and that rapidly resumes its original length to within about 10% after the stress is released.

[0026] Fluoromonomers useful in the practice of the present invention include, for example, vinylidene fluoride (VDF or VF2), tetrafluoroethylene (TFE), trifluoroethylene, chlorotrifluoroethylene (CTFE), hexafluoropropene (HFP), vinyl fluoride, hexafluoroisobutylene, perfluorobutylethylene (PFBE), pentafluoropropene, 3,3,3-trifluoro-1-propene, 2,3,3,3-tetrafluoropropene, fluorinated vinyl ethers, fluorinated allyl ethers, fluorinated dioxoles, and combinations thereof.

[0027] Particularly preferred copolymers produced by the process of the present invention are copolymers of VDF and HFP, TFE or CTFE and contain from about 50 to about 99 weight percent VDF, more preferably from about 70 to about 99 weight percent VDF.

[0028] The term "PVDF" as used herein includes vinylidene fluoride (VDF) homopolymers or copolymers of VDF with at least one other comonomer, where VDF represents at least 50% by weight.

[0029] In some embodiments, the fluoropolymer is selected from homopolymers of vinylidene fluoride and copolymers preferably containing at least 50% by weight of VDF with a comonomer selected from chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene and tetrafluoroethylene.

[0030] Preferably, the fluoropolymer is a polyvinylidene fluoride (PVDF) homopolymer or a copolymer of vinylidene fluoride and hexafluoropropylene, the level of HFP being 50% by weight or less, preferably 40% by weight or less.

[0031] The non-fibrillating binder according to the present invention comprises one or more fluoropolymers.

[0032] The fluoropolymer further comprises a monomer having at least one functional group selected from carboxyl, epoxy, carbonyl or hydroxyl. Examples of monomers that can introduce carboxyl functionality are unsaturated monobasic or dibasic acid monomers in free acid, salt form or anhydride form selected from the group consisting of sulfonic, phosphonic and carboxylic acid groups and their salts or anhydrides. Such monomers are acrylic acid, methacrylic acid, vinylsulfonic acid, vinylphosphonic acid, itaconic acid, maleic acid and salts of such compounds. Examples of monomers that can introduce epoxy functionality are allyl glycidyl ether, methallyl glycidyl ether, crotonic acid glycidyl ether and acetic acid glycidyl ether. An example of a monomer that can introduce carbonyl functionality is ethylene carbonate. Examples of monomers that can introduce hydroxyl functionality are hydroxyethyl acrylate and hydroxypropyl acrylate.

[0033] The functionalizing monomers may be used in an amount of 0.01 to 15 weight percent based on total monomers. Preferably, they are used in an amount of 0.05 to 5 weight percent based on total monomers, and even more preferably, in an amount of 0.05 to 1.5 weight percent based on total monomers.

[0034] Functionalized fluoropolymers are mainly produced by heterogeneous polymerization reactions, including suspension, emulsion and microemulsion systems. Generally, each of these reactions requires at least one acid-functionalized monomer or its salt, at least one fluoromonomer and a radical initiator in a suitable reaction medium. In addition, the emulsion polymerization of halogen-containing monomers generally requires a surfactant that can emulsify both reactants and reaction products during the polymerization reaction.

[0035] According to one embodiment, the fluoropolymers used in the present invention are prepared by an emulsion polymerization process in the absence of fluorinated surfactants.

[0036] In some variations, the functionalized fluoropolymers used in the present invention can be prepared using a manufacturing method similar to that disclosed in WO2012 / 030784. The temperature used for polymerization can vary from 20 to 130° C. The pressure used for polymerization can vary from 280 to 20,000 kPa.

[0037] A pressurized polymerization reactor equipped with an agitator and heat control means is charged with water, preferably deionized water, one or more functionalized monomers and at least one fluoromonomer. The mixture may optionally contain one or more of surfactants, buffers, antifouling agents or chain transfer agents for molecular weight control of the polymer product. Before introducing the monomer or monomers, air is preferably removed from the reactor to obtain an oxygen-free environment for the polymerization reaction. The order of introduction of the polymerization ingredients can be varied, but generally it is preferred that at least a portion of the functionalized monomer is present in the aqueous reaction medium before the start of polymerization of the fluoromonomer. An additional amount of functionalized monomer may be fed into the reactor during the reaction.

[0038] In one embodiment, water, initiator, functionalized monomer, and optionally surfactant, antifoulant, chain transfer agent, and / or buffer are charged to the reactor, and the reactor is heated to the desired reaction temperature. Fluoromonomer is then fed to the reactor, preferably at a rate that provides an essentially constant pressure. Alternatively, fluoromonomer, functionalized monomer, and initiator can be fed to the reactor along with one or more optional components. The monomer feed is terminated when the desired weight of monomer has been fed to the reactor. Additional radical initiator is optionally added, and the reactants are allowed to react for an appropriate time. The reactor pressure is reduced as the monomer in the reactor is consumed.

[0039] Upon completion of the polymerization reaction, the reactor is brought to ambient temperature and the residual unreacted monomers are vented to atmospheric pressure. The aqueous reaction medium containing the fluoropolymer is then recovered from the reactor as a latex. The latex consists of a stable mixture of the reaction components, i.e., water, surfactant, initiator (and / or initiator decomposition products) and functionalized fluoropolymer solids. The latex may contain from about 10 to about 50 weight percent, preferably 20 to 40 weight percent, of polymer solids. The polymer in the latex is in the form of small particles having a size range of about 30 nm to about 800 nm.

[0040] After polymerization, the polymer is stirred, thickened and dried.

[0041] Fluoropolymer powders can be obtained by various manufacturing methods. They can be obtained by emulsion or suspension synthesis manufacturing methods, by drying by spray drying or directly by freeze drying. Powders can also be obtained by comminution techniques such as freeze-grinding, in which the product is brought to a temperature below room temperature before grinding, for example using liquid nitrogen.

[0042] The fluoropolymer powder has a particle size characterized by a diameter Dv50 of less than 10 μm and Dv90 of less than 25 μm. If at the end of the powder production step, i.e. after the polymerization and drying steps, Dv50 and Dv90 are greater than 10 μm and 25 μm, respectively, the particle size can be adjusted and optimized by selection or screening methods and / or by grinding.

[0043] A suitable method for reducing the particle size of the non-fibrillizable binder is the pressurized jet milling manufacturing method. For example, the non-fibrillizable binder can be placed in an air jet mill and "air jet milled" to reduce the particle size to have a Dv50 of less than 10 μm and a Dv90 of less than 25 μm.

[0044] The present invention also aims to provide a dry coated electrode for a Li-ion battery, comprising the non-fibrillizable binder, a conductive agent and a dry active material.

[0045] The mass composition of the dry-coated electrode is: - 50% to 99.9% active material, preferably 50% to 99.9% active material, - 25% to 0.05%, preferably 25% to 0.5%, of a conductive agent, - 25 to 0.05%, preferably 25 to 0.5%, of a non-fibrillating binder, - 0-5% of at least one additive selected from plasticizers, ionic liquids, dispersants for conductive additives, and flow aids; All these percentages add up to 100%.

[0046] The conductive agent in the dry-coated electrode includes one or more materials that can improve electrical conductivity. Some examples include carbon black such as acetylene black and ketjen black, carbon nanotubes, carbon nanofibers, carbon fibers such as vapor-grown carbon fibers, and metal powders such as SUS powder and aluminum powder.

[0047] The active material is a material capable of absorbing and releasing lithium ions.

[0048] According to one embodiment, the electrode is an anode.

[0049] According to one embodiment, the electrode is a cathode.

[0050] Some examples of positive electrode active materials are LiCoO2, Li(Ni,Co,Al)O2, Li (1+x) , Ni a Mn b Co c (x is a real number equal to or greater than 0; a = 0.8, 0.6, 0.5, or 1 / 3; b = 0.1, 0.2, 0.3, or 1 / 3; c = 0.1, 0.2, or 1 / 3), LiNiO2, LiMn2O4, LiCoMnO4, Li3NiMn3O3, Li3Fe2(PO4)3, Li3V2(PO4)3, Li 1+x Mn 2-x-y M y LiMn spinel substituted with a different element having a composition represented by O4 (wherein M represents at least one metal selected from Al, Mg, Co, Fe, Ni, and Zn, and x and y each independently represent a real number of 0 to 2), and lithium titanate Li x TiO y (x and y are independently a real number between 0 and 2), and lithium metal phosphate having a composition represented by LiMPO4 (M represents Fe, Mn, Co, or Ni). Among these, Ni is preferred as a positive electrode active material. 0.8 Mn 0.1 Co 0.1 It is preferable to use:

[0051] The surfaces of the above materials may be coated. The coating material is not particularly limited as long as it has lithium ion conductivity and contains a material that can be held in the form of a coating layer on the surface of the active material. Examples of coating materials include LiNbO3, Li4Ti5O 12 , Li3PO4.

[0052] The shape of the positive electrode active material is not particularly limited, but it is preferably in the form of particles.

[0053] Examples of the negative electrode active material include lithium alloys, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicon alloys, and Li4TiO 12 Graphite is preferred.

[0054] The shape of the negative electrode active material is not particularly limited, but it is preferably in the form of particles.

[0055] The present invention also relates to a method for producing a dry-coated electrode, - mixing an active material, a non-fibrillizable polymeric binder in powder form as described above, and a conductive agent using a process that provides an electrode formulation that can be applied to a metal substrate by a solvent-free process; - depositing said electrode formulation on a substrate by a solvent-free process to obtain a Li-ion battery electrode; - consolidating said electrode by thermomechanical treatment (application of temperatures up to 50° C. above the melting temperature of the polymer together with mechanical pressure); The method includes:

[0056] A "solvent-free" process is one that does not require a residual solvent evaporation step after the deposition step.

[0057] According to one embodiment, after the powder mixing step, the electrode is manufactured by depositing the formulation on a metal substrate by a solvent-free spray process, by a pneumatic spray process, by electrostatic spraying, by immersion in a fluidized powder bed, by sprinkling, by electrostatic screen printing, by deposition with a rotating brush, by deposition with a charging rotating roll, by calendaring.

[0058] According to one embodiment, after the powder mixing step, the electrode is manufactured in two steps by a solvent-free spray process. The first step consists in producing a free-standing film from the premixed formulation using a thermomechanical process such as extrusion, calendaring or thermocompression. In the second step, the free-standing film is laminated onto a metal substrate by a process combining temperature and pressure such as calendaring or thermocompression.

[0059] The mass ratio of the conductive agent to the active material is preferably 0.1 to 10%, and more preferably 0.5 to 7%.

[0060] The mass ratio of the binder to the active material is preferably 0.1 to 10%, and more preferably 0.5 to 7%.

[0061] According to one embodiment, all of the electrode components are mixed at once according to conventional methods to provide the electrode formulation.

[0062] In one embodiment, the electrode formulation is applied to a substrate by electrostatic screen printing. Some examples of substrates are current collectors such as metal foils and metal meshes, polymer films, or solid electrolyte layers of solid-state batteries.

[0063] The preferred thickness of the electrode is 0.1 μm to 1000 μm, preferably 0.1 μm to 300 μm.

[0064] Another subject of the invention is a Li-ion battery comprising a positive electrode, a negative electrode and a separator, at least one electrode being a dry-coated electrode as defined above. EXAMPLES

[0065] The following examples illustrate the invention without limiting it.

[0066] <Material> PVDF 1: A homopolymer of vinylidene fluoride functionalized with acrylic acid moieties, having a functionalization rate of about 1% by weight and a melting temperature of 165° C. PVDF 2: A copolymer of vinylidene fluoride and hexafluoropropylene (about 5% by weight of HFP) containing acrylic acid moieties with a functionality of about 1% by weight and characterized by a melting temperature of 145°C.

[0067] <Method> Particle size distribution measurements: Measurements are performed on powders using a Malvern INSITEC System particle size analyzer by dry path laser diffraction at a focus of 100 mm.

[0068] The melting temperature is measured by DSC (differential scanning calorimetry) according to standard ISO 11357-3 and is measured at the peak of the melting endotherm.

[0069] <Reduction in binder particle size> PVDF1 and PVDF2 were air-jet milled using a lab-scale apparatus manufactured by Hosokawa to reduce particle size.

[0070] <Cathode 1> LMO, Super P Li (Imerys) and PVDF1 were added into a 100 ml plastic bottle with a lid. The weight ratio of LMO, Super P Li and PVDF1 was 90:5:5. The powders were mixed on a mixing rotor at 110 rpm for 1 hour. The mixed powder was applied to an aluminum foil placed 1 cm away from the screen with a TS-1 (electrostatic screen printing equipment, Berg Co., Ltd.) at 1 kV. The printed powder together with the foil was compressed in a roll press (SA-602, Tester Industry) at room temperature, 29.4 kN load, and 0.5 m / min speed. The prepared electrodes were tested for peel strength according to the 180° peel test method of ASTM D903 with some modifications.

[0071] <Cathode 2> The same method was used for the preparation of Cathode 1, except that the binder was changed to air-jet milled PVDF1.

[0072] <Cathode 3> The same method as in the preparation of Cathode 1 was used, except that the binder was changed to PVDF2.

[0073] <Cathode 4> The same method was used for the preparation of cathode 1, except that the binder was changed to air-jet milled PVDF2.

[0074] <Anode 1> 158-C (graphite, BTR) and PVDF1 were added into a 100 ml plastic bottle with a lid. The weight ratio of 158-C to PVDF1 was 95:5. The powders were mixed on a mixing rotor at 110 rpm for 1 hour. The mixed powder was applied to a copper foil placed 1 cm away from the screen with a TS-1 (electrostatic screen printing equipment, Berg Co., Ltd.) at 1 kV. The printed powder together with the foil was compressed in a roll press (SA-602, Tester Industry) at 60°C, 14.7 kN load, and 0.5 m / min speed. The prepared electrodes were tested for peel strength according to the 180° peel test method of ASTM D903 with some modifications. Peel strength values ​​below 1 N / m were considered not OK (abbreviated as "NOK") because the electrodes were too fragile to be handled.

[0075] <Anode 2> The same method as for the preparation of Anode 1 was used, except that the binder was changed to air-jet milled PVDF1.

[0076] <Anode 3> The same method as in the preparation of Anode 1 was used, except that the binder was changed to PVDF2.

[0077] <Anode 4> The same method was used for the preparation of Anode 1, except that the binder was changed to air-jet milled PVDF2.

[0078] The results of the peel test are shown in Figures 1 and 2.

[0079] FIG. 1 shows the peel test results for cathodes 1, 2, 3, and 4.

[0080] FIG. 2 shows the peel test results of Anodes 1, 2, 3, and 4.

[0081] Anodes 1, 3 and 4 were not subjected to peeling tests because homogeneous electrodes were not obtained.

[0082] The particle size distribution (PSD) and adhesion results of the non-fibrillizable binders are shown in Table 1 below.

[0083] [Table 1]

Claims

1. A non-fibrillable binder for dry coated electrodes, comprising a fluoropolymer powder having a particle size distribution with a D50 of less than 10 μm, preferably less than 5 μm, and a D90 of less than 25 μm, preferably less than 15 μm.

2. 2. The binder of claim 1, wherein the fluoropolymer comprises at least one fluoromonomer selected from vinylidene fluoride, tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene, hexafluoropropene, vinyl fluoride, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, 3,3,3-trifluoro-1-propene, 2,3,3,3-tetrafluoropropene, fluorinated vinyl ethers, fluorinated allyl ethers, and fluorinated dioxoles.

3. 2. The binder of claim 1, wherein the fluoropolymer is selected from homopolymers of vinylidene fluoride and copolymers containing at least 50% by weight of VDF, the comonomer being selected from chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene and tetrafluoroethylene.

4. 2. The binder of claim 1, wherein the fluoropolymer is a polyvinylidene fluoride (PVDF) homopolymer or a copolymer of vinylidene fluoride and hexafluoropropylene.

5. 10. The binder of claim 1, wherein the fluoropolymer comprises functionalized monomers in an amount of 0.01 to 15 weight percent based on total monomers, preferably 0.05 to 5 weight percent based on total monomers, and even more preferably 0.05 to 1.5 weight percent based on total monomers.

6. 6. The binder of claim 5, wherein the functionalized monomer having at least one functional group is selected from acrylic acid, methacrylic acid, vinyl sulfonic acid, vinyl phosphonic acid, itaconic acid, maleic acid, and salts of such compounds; allyl glycidyl ether, methallyl glycidyl ether, crotonic acid glycidyl ether, and acetic acid glycidyl ether; ethylene carbonate, hydroxyl ethyl acrylate, and hydroxyl propyl acrylate.

7. A dry-coated electrode comprising the non-fibrillizable binder of claim 1, a conductive agent, and a dry active material.

8. - 50% to 99.9%, preferably 50% to 99.9%, of active material, - 25% to 0.05%, preferably 25% to 0.5%, of a conductive agent, - 25 to 0.05%, preferably 25 to 0.5%, of a non-fibrillating binder, - 0-5% of at least one additive selected from plasticizers, ionic liquids, dispersants for conductive additives, flow aids and having a mass composition of 8. The dry-coated electrode of claim 7, wherein the sum of all these percentages is 100%.

9. 8. The dry-coated electrode according to claim 7, wherein the conductive agent comprises one or more materials selected from the group consisting of carbon black such as acetylene black and ketjen black; carbon fibers such as carbon nanotubes, carbon nanofibers, and vapor-grown carbon fibers; and metal powders such as SUS powder and aluminum powder.

10. For the positive electrode, the active material is LiCoO ２ , Li(Ni,Co,Al)O ２ , Li （１＋ｘ） , Ni ａ Mn ｂ Co ｃ (x represents a real number equal to or greater than 0; a = 0.8, 0.6, 0.5, or 1 / 3; b = 0.1, 0.2, 0.3, or 1 / 3; c = 0.1, 0.2, or 1 / 3); LiNiO ２ , LiMn ２ O ４ , LiCoMnO ４ , Li ３ NiMn ３ O ３ , Li ３ Fe ２ (P.O. ４ ) ３ , Li ３ V ２ (P.O. ４ ) ３ , Li １＋ｘ Mn ２－ｘ－ｙ M ｙ O ４ (wherein M represents at least one metal selected from Al, Mg, Co, Fe, Ni, and Zn, and x and y independently represent real numbers between 0 and 2), lithium titanate Li ｘ TiO ｙ (x and y independently represent real numbers between 0 and 2), and LiMPO ４ 8. The dry-coated electrode according to claim 7, wherein M is selected from lithium metal phosphates having a composition represented by the formula:

11. Regarding the negative electrode, the active material is selected from the group consisting of lithium alloys, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicon alloys, and Li ４ TiO １２ 8. The dry-coated electrode of claim 7, wherein the electrode is selected from the group consisting of:

12. A method for producing the dry-coated electrode according to any one of claims 7 to 11, comprising: - mixing an active material, a non-fibrillizable polymer binder in powder form and a conductive agent using a process that provides an electrode formulation that can be applied to a metal substrate by a solvent-free process; - depositing said electrode formulation on a substrate by a solvent-free process to obtain a Li-ion battery electrode; - consolidating said electrode by thermomechanical treatment; A method comprising:

13. A Li-ion battery comprising a positive electrode, a negative electrode, and a separator, wherein at least one electrode is the dry-coated electrode according to any one of claims 7 to 11.

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