METHOD FOR MANUFACTURED A POROUS ELECTRODE, AND A BATTERY CONTAINING SUCH AN ELECTRODE

Abstract

The present invention relates to a porous electrode usable in electrical energy storage or production devices, such as a lithium-ion battery. This porous electrode is a porous layer comprising at least one active electrode material P and an electronically conductive oxide material.

Description

Title of the invention: METHOD FOR MANUFACTURING A POROUS ELECTRODE, AND BATTERY CONTAINING SUCH AN ELECTRODE Technical field of the invention

[0001] The invention relates to energy storage or production devices. It relates more specifically to electrodes usable in energy storage or production devices such as capacitors, photovoltaic cells or ion insertion batteries, in particular lithium ion, sodium ion or potassium ion batteries. The invention applies to negative electrodes and positive electrodes. It relates to porous electrodes which can be impregnated with an ionic conductive phase such as a solid electrolyte without a liquid phase or a liquid electrolyte.

[0002] The invention also relates to a method for preparing such a porous electrode which uses primary particles of at least one active electrode material and at least one precursor of an electronically conductive oxide material, and the electrodes thus obtained. The invention also relates to a method for manufacturing an energy storage or production device, in particular a method for manufacturing a lithium ion battery comprising at least one of these electrodes, and the batteries thus obtained. State of the art

[0003] Lithium ion batteries have the best energy density among the various electrochemical storage technologies available on the market. There are different electrode architectures and chemical compositions for producing these batteries. The manufacturing processes for lithium ion batteries are presented in numerous articles and patents; an overview is given in the book "Advances in Lithium-Ion Batteries" (ed. W. van Schalkwijk and B. Scrosati), published in 2002 (Kluever Academie / Plénum Publishers).

[0004] There is a growing need for very small rechargeable batteries, capable of being integrated on electronic cards; these electronic circuits can be used in many fields, for example in cards for securing transactions, in electronic labels, in implantable medical devices, in various micromechanical systems.

[0005] There is also a growing need for high-capacity rechargeable batteries, particularly to power transport devices (electric bicycles, scooters, electric motorcycles, electric cars, electric utility vehicles) and for the electrical energy storage, for example to store electricity produced by intermittent electricity generators (wind turbines, photovoltaic panels) or to stabilize an electricity network subject to highly fluctuating supply and demand.

[0006] There is also a growing need for intermediate-sized rechargeable batteries for various stand-alone and portable devices (e.g., cell phones, laptops, power tools, intermittent-use kitchen appliances).

[0007] In all these applications, the possibility of rapid recharging of the battery is a highly valued feature. Similarly, these batteries must not present a risk of thermal runaway. And finally, it is desirable that they can operate over a wide temperature range.

[0008] According to the state of the art, the electrodes of lithium ion batteries can be manufactured using coating techniques, in particular by coating. These methods make it possible to deposit on the surface of a substrate, an ink consisting of particles of active materials in the form of powder; the particles constituting this powder have an average particle size which is typically between 5 μm and 15 μm in diameter.

[0009] These deposition techniques, in particular by coating, make it possible to produce layers with a thickness of between approximately 20 μm and approximately 400 μm. The power and energy of the battery can be modulated by adapting the thickness and porosity of the layers, the size of the active particles that constitute them and by the presence of various constituents within the layer such as binders or even electronically conductive materials. To produce microbatteries, it is desirable to have a smaller thickness for each constituent layer of the microbattery.

[0010] In addition to the problems related to the formulation of inks to obtain a high-performance electrode at low manufacturing cost, it must be kept in mind that the ratio between the energy density and the power density of the electrodes can be adjusted according to the particle size of active materials, and indirectly to the specific surface area of ​​the electrode layers and their thickness. The article by J. Newman (“Optimization of Porosity and Thickness of a Battery Electrode by Means of a Reaction-Zone Model”, J. Electrochem. Soc., 142 (1), p. 97-101 (1995)) demonstrates the respective effects of the thicknesses of the electrodes and their porosity on their discharge regime (power) and energy density.

[0011] Binder-free mesoporous electrode layers for lithium ion batteries can be deposited by electrophoresis; this is known from WO 2019 / 215 407 (LTEN). They can be impregnated with a liquid electrolyte, but their electrical resistivity remains quite high.

[0012] To increase the low electronic conductivity of the electrodes, especially when these electrodes are of high thickness or made from poorly electronically conductive electrode active materials, a certain amount of electronically conductive material, such as carbon black, is usually added to the electrode active material particles. Ideally, the electronically conductive particles should be available at every point on the surface of the electrode active material particle to allow simultaneous insertion / deinsertion over the entire surface of the electrode active particles, thus maximizing current density and minimizing local stress and heating due to inhomogeneous electrical transport.

[0013] In practice, it is very difficult to control the arrangement of the carbon black within the electrodes. Moreover, with the increasing use of smaller and smaller active material particles, these problems are even more preponderant. A non-uniform distribution of the carbon black in the electrode induces a much higher polarization of the electrode, which leads to an increase in the series resistance of the battery comprising such an electrode. These local charge state imbalances will be all the more pronounced as the current density increases. These imbalances consequently induce a loss of cycling performance, a safety risk and a limitation of the power of the battery cell. The same is true when the electrodes have inhomogeneous porosity, i.e. distributed in size; this inhomogeneity contributes to making the wetting of the pores of the electrodes more difficult.

[0014] In this context and in order to reduce the electrical resistivity of the electrodes, the applicant has developed a mesoporous electrode comprising a mesoporous layer of at least one active electrode material having on and inside the pores of this mesoporous layer, a carbonaceous coating; this is known from WO 2021 / 220 174 (I-TEN). The presence of this carbonaceous electronically conductive coating on the electrode makes it possible to reduce its electrical resistivity but does not make it possible to significantly increase its voltage and temperature resistance and its electrochemical stability. In addition, the production of a carbonaceous electronically conductive coating on the electrode is expensive and difficult to implement.

[0015] As there is a growing need for very small rechargeable batteries, the electrodes must meet increasingly stringent specifications. They must have high chemical and electrochemical stability, strength and corrosion resistance so as to give the batteries comprising them high cycling performance, storage stability, temperature stability and long-term reliability and combine high energy density with high power density. The present invention seeks to remedy at least in part the drawbacks of the prior art mentioned above.

[0016] More specifically, the problem that the present invention seeks to solve is to provide a method for manufacturing porous electrodes having electrical conductivity high, homogeneous electronics and controlled pore density that is simple, safe, fast, easy to implement, inexpensive.

[0017] The present invention also aims to provide safe porous electrodes having high electronic conductivity, a stable mechanical structure, good thermal stability, especially at high temperature, a long service life, regardless of the thickness of the electrode,

[0018] Another object of the invention is to provide electrodes for batteries capable of operating at high temperature without reliability problems and without risk of fire.

[0019] Another object of the invention is to provide porous electrodes which, in addition to the preceding characteristics, can easily be wetted and impregnated with an ionic liquid or a polymer.

[0020] Another aim of the invention is to provide a method for manufacturing an energy storage or production device such as a capacitor, a supercapacitor, a hybrid supercapacitor, a photovoltaic cell, a photoelectrochemical cell, a battery, in particular a lithium ion, sodium ion or potassium ion battery, comprising a porous electrode according to the invention.

[0021] Yet another object of the invention is to propose energy storage or production devices such as batteries, in particular lithium ion batteries and microbatteries, capacitors, supercapacitors, hybrid supercapacitors such as the lithium ion hybrid supercapacitor hereinafter LiC ("Lithium-Ion Capacitor" in English), the sodium ion hybrid supercapacitor hereinafter SIHC ("sodium-ion hybrid capacitor" in English), the potassium ion hybrid supercapacitor hereinafter PIHC ("potassium-ion hybrid capacitors" in English), capable of storing high energy densities, of restoring this energy with very high power densities (in particular in capacitors or supercapacitors), of withstanding high temperatures which have an excellent cycling life as well as increased safety. Objects of the invention

[0022] In order to increase the performance of electrodes usable in energy storage or production devices, in particular in conventional lithium ion batteries, in particular by reducing their electrical resistivity while significantly increasing their voltage and temperature resistance and their electrochemical stability, the inventors sought to find an alternative to the carbon electronic conductive coating presented in application WO 2021 / 220 174 (LTEN).

[0023] According to the invention, the problem is solved by an electrode for a lithium ion, sodium ion or potassium ion battery which is completely ceramic, porous free of organic binders, the porosity of which is between 25% and 60% by volume. The electrode according to the invention is a porous, preferably mesoporous, layer comprising at least one active electrode material and an electronically conductive oxide material, the porosity of which is between 25% and 60% by volume. Advantageously, the electrode according to the invention comprises zones of active electrode material P coated at least in part with a coating of an electronically conductive oxide material throughout the internal volume of the electrode as well as on the surface, preferably the electrode according to the invention comprises zones of active electrode material P coated with a coating of an electronically conductive oxide material throughout the internal volume of the electrode as well as on the surface.

[0024] This porous, preferably mesoporous, entirely solid layer, without organic components, is obtained from primary particles of at least one active electrode material and at least one precursor of an electronically conductive oxide material. The sizes of the primary particles can be between a few nanometers and a few micrometers.

[0025] After transformation of the precursor of an electronically conductive oxide material into an electronically conductive oxide material, and sintering, a porous, preferably mesoporous, layer or a plate is obtained, without carbon black or organic binders, in which all the primary particles are welded together (by the necking phenomenon, known elsewhere) to form a continuous mesoporous network. The porous, preferably mesoporous, layer thus obtained is entirely solid and ceramic. There is no longer any risk of loss of electrical contact between the particles of active materials during cycling, which is likely to improve the cycling performance of the battery.

[0026] The heat treatments carried out at high temperature to sinter the particles together make it possible to dry the electrode perfectly and to eliminate all traces of water or solvents or other organic additives (stabilizers, binders) adsorbed on the surface of the particles of active material. The high-temperature heat treatment (sintering) may be preceded by a lower-temperature heat treatment (debinding) to dry the electrode placed or deposited and to eliminate traces of water or solvents or other organic additives (stabilizers, binders) adsorbed on the surface of the particles of active material; this debinding may be carried out in an oxidizing atmosphere.

[0027] Depending on the sintering times and temperatures, it is possible to adjust the porosity of the final electrode. Depending on the energy density requirements, the latter can be adjusted in a range between 25% and 60% porosity.

[0028] In all cases, the power density of the electrodes thus obtained remains extremely high due to the porosity, preferably due to the mesoporosity. Moreover, regardless of the size of the mesopores in the active material (knowing that after sintering the notion of particle no longer applies to the material which then presents a three-dimensional structure with a network of channels and mesopores), the dynamic balancing of the cell remains perfect, which contributes to maximizing the power densities and lifetimes of the battery cell.

[0029] The electrode according to the invention has a high specific surface area, which reduces the ionic resistance of the electrode. However, for this electrode to deliver maximum power, it is still necessary for it to have very good electronic conductivity to avoid ohmic losses in the battery. This improvement in the electronic conductivity of the cell will be all the more critical as the thickness of the electrode increases. Furthermore, this electronic conductivity must be perfectly homogeneous throughout the electrode in order to avoid having locally more electrically resistive zones which could lead to the formation of a hot spot during the power operation of the battery.

[0030] According to an essential characteristic of the present invention, the electrode according to the invention comprises at least one active electrode material and an electronically conductive oxide material, preferably comprises areas of active electrode material P coated at least in part with a coating of an electronically conductive oxide material throughout the internal volume of the electrode as well as on the surface, preferably comprises areas of active electrode material P coated with a coating of an electronically conductive oxide material as well as on the surface, more preferably made of SnO2, aluminum-doped ZnO (ZnO:Al, preferably having a Zn:Al molar ratio of between 1:0.015 and 1:0.05), MoO3, SrMoO3, In2O3, Ga2O3, or indium-tin oxide, throughout the internal volume of the electrode, in a perfectly distributed manner.The thickness of the coating of an electronically conductive oxide material in the entire internal volume of the electrode is advantageously less than 10 nm, preferably less than 7 nm, preferentially less than 5 nm, more preferentially between 5 nm and 3 nm and even more preferentially less than 3 nm. This electronically conductive oxide material can be produced from at least one precursor of said electronically conductive oxide material, in particular from at least one liquid precursor of said electronically conductive oxide material.

[0031] Indeed, as explained above, the method according to the invention, which necessarily involves a step of forming a layer from primary particles of electrode material (active material) and at least one precursor of an electronically conductive oxide material, causes the particles to "weld" naturally together to generate, after consolidation such as annealing, a porous, rigid, three-dimensional structure, without organic binder; this porous layer, preferably mesoporous, is perfectly suited to the application of a surface treatment, by gas or liquid means, or an impregnation which penetrates into the depth of the open porous structure of the layer.

[0032] A first subject of the invention is a method of manufacturing a porous electrode, in particular for devices for storing or producing electrical energy, said electrode being a porous layer comprising at least one active electrode material P and an electronically conductive oxide material, said electrode being free of binder, having a porosity of between 25% and 60% by volume, preferably between 25% and 50%, said manufacturing method being characterized in that:

[0033] (a) at least one precursor of an electrically conductive oxide material is supplied electronics, a colloidal suspension, a paste or a preparation comprising primary particles of at least one active electrode material P, and optionally a substrate, knowing that said substrate can be a substrate capable of acting as an electric current collector, or be an intermediate substrate,

[0034] (b) mixing said precursor(s) of an electrically conductive oxide material tronic and said colloidal suspension or said paste or said preparation comprising primary particles, of at least one active electrode material P supplied in step (a), so as to form a mixture,

[0035] (c) a layer is formed from the mixture obtained at the end of step (b), by a process selected from the group formed by: electrophoresis, a printing process, preferably inkjet printing or flexographic printing, a coating process, preferably by doctor blade, roller, curtain, dip-shrink, or through a slot-shaped die, or an extrudate is formed from the mixture obtained at the end of step (b) by extrusion,

[0036] (d) drying said layer obtained in step (c), so as to obtain a layer dried, where appropriate, said dried layer is separated from its intermediate substrate after the drying step, and / or a heat treatment is carried out, preferably in an oxidizing atmosphere, of said dried layer obtained following the drying of step (d) or of said extrudate obtained at the end of step (c);

[0037] (e) the transformation of the precursor(s) of an oxide material is carried out electronic conductor made of electronically conductive oxide material,

[0038] (f) said layer or said extrudate obtained at the end of step (e) is consolidated, by thermal and / or mechanical treatment, preferably by sintering, to obtain a porous, preferably mesoporous, electrode,

[0039] it being understood that steps (d), (e) and (f), preferably steps (e) and (f), can be carried out during the same heat treatment step.

[0040] Advantageously, after step (f), the pores of said porous electrode are impregnated with an electrolyte. Depending on the type of battery in question, the electrolyte may comprise either a lithium salt, a potassium salt or a sodium salt. The electrolyte is preferably a phase carrying lithium ions, sodium ions or potassium ions selected from the group consisting of: • an electrolyte composed of at least one aprotic solvent and at least one lithium, sodium or potassium salt; • an electrolyte composed of at least one ionic liquid and at least one lithium, sodium or potassium salt; • a mixture of at least one aprotic solvent and at least one ionic liquid and at least one lithium, sodium or potassium salt; • an ionic liquid polymer; • a polymer made ionically conductive by the addition of at least one lithium, sodium or potassium salt; and • a polymer made ionically conductive by the addition of a liquid electrolyte, either in the polymer phase or in the porous structure of the porous electrode,

[0041] or by an ionically conductive polymer, preferably chosen from polyethylene oxide (PEO), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), poly(propylene carbonate) (PPC), poly(ethylene carbonate) (PEC), poly(vinyl carbonate) (PVC), polyvinylidene fluoride (PVDF), polypropylene glycol (PPG), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly-dimethylsiloxane (PDMS), poly(e-caprolactone) (PCL) and poly(tri methylene carbonate) (PTMC).

[0042] The lithium ion-carrying phase may comprise a mixture of several ionic liquids. Advantageously, the ionic liquid may be a cation of the l-Ethyl-3-methylimidazolium type (also called EMI+) and / or n-propyl-n-methylpyrrolidinium (also called PYRi3+) and / or n-butyl-n-methylpyrrolidinium (also called PYRi4+), associated with anions of the bis(trifluoromethanesulfonyl)imide (TFSE) and / or bis(fluorosulfonyl)imide (FSE) type. To form an electrolyte, a lithium salt such as LiTFSI may be dissolved in the ionic liquid which serves as a solvent or in a solvent such as γ-butyrolactone. γ-butyrolactone prevents the crystallization of the ionic liquids, inducing a wider operating temperature range for the latter, particularly at low temperatures. The sodium or potassium ion-carrying phase may comprise a mixture of several ionic liquids.The lithium, sodium or potassium ion-carrying phase may comprise an ionic liquid polymer, such as a poly(l-vinyl-3-alkyl-imidazolium) or a poly(l-vinyl-N-alkyl-pyrrolidinium).

[0043] In step (c) the formation of a layer can be done on one or both sides of the substrate.

[0044] Advantageously, when said substrate is an intermediate substrate, the following are separated: said layer of said intermediate substrate in step (d) after drying of said layer, to form, in particular after consolidation, a porous plate.

[0045] Advantageously, when said substrate is an intermediate substrate, after step (f), an electrically conductive sheet is provided, covered on at least one face, respectively on both of its faces, with a thin layer of conductive adhesive, then at least one porous plate is bonded to one face, preferably to each of the faces, of the electrically conductive sheet, so as to obtain a porous plate or layer, preferably mesoporous on a substrate capable of acting as a current collector. In the present application, the terms "porous layer" and "porous plate" are interchangeable.

[0046] Advantageously, step (b) is carried out by bringing the colloidal suspension of the paste supplied in step (a) comprising primary particles of at least one active electrode material P into contact with a liquid phase comprising at least one precursor of said electronically conductive oxide material, and said transformation of the precursor(s) of an electronically conductive oxide material into an electronically conductive oxide material during step (e) is carried out by heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere.

[0047] Advantageously, said precursor(s) of the electronically conductive oxide material is chosen from organic salts containing one or more metallic elements capable, after heat treatment such as calcination, of forming an electronically conductive oxide, and said transformation into an electronically conductive material is a heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere.

[0048] These organic salts are preferably chosen from:

[0049] - an alcoholate of at least one metallic element capable, after heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, to form an electronically conductive oxide,

[0050] - a nitrate of at least one metallic element capable, after heat treatment such that a calcination, preferably carried out in air or in an oxidizing atmosphere, forms an electronically conductive oxide,

[0051] - an oxalate of at least one metallic element capable, after heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, to form an electronically conductive oxide, and

[0052] - an acetate of at least one metallic element capable, after heat treatment such that a calcination, preferably carried out in air or in an oxidizing atmosphere, forms an electronically conductive oxide,

[0053] and / or preferably, the metallic element is chosen from tin, zinc, indium, gallium, molybdenum or a mixture of two or three or four or five of these elements.

[0054] The metallic element may comprise at least one doping element.

[0055] Advantageously, said porous layer obtained at the end of step (f) has a specific surface area of ​​between 10 m2 / g and 500 m2 / g and / or a thickness of between 2 pm and 400 pm, preferably between 2 pm and 300 pm, more preferably between 3 pm and 200 pm.

[0056] Advantageously, said porous electrode obtained at the end of step (f) has a specific surface area of ​​between 10 m2 / g and 500 m2 / g and / or a thickness of between 2 μm and 20 μm when the substrate is a substrate capable of acting as an electric current collector.

[0057] Advantageously, said porous electrode obtained at the end of step (f) has a specific surface area of ​​between 10 m2 / g and 500 m2 / g and / or a thickness of between 25 μm and 500 μm, preferably between 50 μm and 400 μm, when the substrate is an intermediate substrate.

[0058] Advantageously, when said colloidal suspension or paste or preparation supplied in step (a) comprises organic additives, such as ligands, stabilizers, binders or residual organic solvents, the heat treatment of step (d) is carried out, preferably under an oxidizing atmosphere, of said dried layer or of said extrudate obtained at the end of step (c) according to the invention, or of said porous plate according to the invention, it being understood that this heat treatment and steps (d), (e) and (f), preferably steps (e) and (f), can be carried out during the same heat treatment step.

[0059] Advantageously, said active electrode material P is an active electrode material PC selected from the group formed by: • the oxides LiMn2O4, Lii+xMn2xO4 with 0 < x < 0.15, LiCoO2, LiNiO2, LiMn^Ni 0>5O4, LiMn|XNi0xxXxO4 where X is selected from Al, Fe, Cr, Co, Rh, Nd, other rare earths such as Sc, Y, Lu, La, Ce, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and where 0 < x < 0.1, LiMn2xMxO4 with M = Er, Dy, Gd, Tb, Yb, Al, Y, Ni, Co, Ti, Sn, As, Mg or a mixture of these compounds and where 0 < x < 0.4, LiFeO2, LiMni / 3Nii / 3Coi / 302 jLiNio.8Coo.i5Alo.o502jLiAlxMn2_x04withO< x < 0.15, LiNii / xCoi / yMni / zO2 with x+y+z =10; • LixMy02 where 0.6 <y<0.85; 0<x+y<2; et M est choisi parmi Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Sn, and Sb ou un mélange de ces éléments ; Lii.2oNbo.2oMno.6o02 ; • Lii+xNbyMezApO2 where Me is at least one transition metal chosen from: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Te, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, and where 0.6 <x<l; 0<y<0.5; 0.25<z<l; avec A Me and A Nb, and 0 <p<0.2 ; • LixNby_aNaMz_bPbO2_cFc where 1.2 <x<1.75; 0<y<0.55; 0.1<z<l; 0<a<0.5; 0<b<l; 0<c<0.8; et où M, N, et P sont chacun au moins un des éléments choisi dans le groupe constitué par Ti, Ta, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Zr, Y, Mo, Ru, Rh, Ce et Sb ; • Lih25Nb0.25Mn0.50O2; Lih3Nb0.3Mn0.40O2; Lih3Nb0.3Fe0.40O2; Lih3Nbo.43Nio.27O2; Li1.3Nb0.43Co0.27O2; Li14Nbo.2Mno.53O2; • LixNi0.2Mn0.6Oy where 0.00 <x<1.52; 1.07<y<2.4 ; Li1.2Nio.2Mno.6O2; • LiNixCoyMni_x_yO2 where 0 < x and y < 0.5; LiNixCezCoyMni x yO2 where 0 < x and y < 0.5 and 0 < z; • the phosphates LiFePO4, LiMnPO4, LiCoPO4, LiNiPO4, Li3V2(PO4)3j Li2MPO4 F with M = Fe, Co, Ni or a mixture of these different elements, LiMPO4F with M = V, Fe, T or a mixture of these different elements; the phosphates of formula LiMM'P04, with M and M' (M M') selected from Fe, Mn, Ni, Co, V such as LiFexCoi xPO4et where 0 < x < 1; • FeogCoo iOF; FeF3; LiMSO4F with M = Fe, Co, Ni, Mn, Zn, Mg; • titanium oxysulfides (TiOySz with z=2-y and 0.3 <y<l), les oxysulfures de tungstène (WOySz avec 0.6<y<3 et 0.1<z<2), CuS, CuS2, LixV2O5avec 0 < x < 2, LixV3O8avec 0 < x < 1,7, LixTiS2 avec 0 < x < 1, les oxysulfures de titane et de lithium LixTiOySzavec z=2-y, 0,3<y<l et 0 < x < 1, LixWOySzavec z=2-y, 0,3<y<l et 0 < x < 1, LixCuS avec 0 < x < 1, LixCuS2avec 0 < x < 1.

[0060] Advantageously, said aforementioned PC electrode active material is used to manufacture a cathode.

[0061] Advantageously, said active electrode material P is an active electrode material PA selected from the group formed by: • Li4Ti50i2, Li4Ti5 xMxOi2 with M = V, Zr, Hf, Nb, Ta and 0 < x < 0.25; • niobium oxides and mixed oxides of niobium with titanium, germanium, cerium or tungsten, and preferably in the group formed by: • Nb2O5±ô, Nb12WO33±ô, NbuVACW, Nb18W16O93±ô, Nb16W5O55±ô with 0 < ô < 2, LiNbO3, • TiNb2O7±ô, LiwTiNb2O7 with w>0, TihXM'xNb2 yM2yO7±ô or LiwTii xM'xNb2 yM 2yO7±ô in which M1 and M2 are each at least one element selected from the group consisting of Nb, V, Ta, Fe, Co, Ti, Bi, Sb, As, P, Cr, Mo, W, B, Na, Mg, Ca, Ba, Pb, Al, Zr, Si, Sr, K, Cs and Sn, M1 and M2 being the same or different from each other, and in which 0 <w<5et0<x< 1 et 0 < y < 2 et 0 < ô < 0,3 ; • LaxTih2xNb2+xO7 where 0 <x<0.5 ; • MxTii_2xNb2+xO7±ô • in which M is an element whose oxidation state is +III, more particularly M is at least one of the elements chosen from the group consisting of Fe, Ga, Mo, Al, B, and where 0 <x<0.20 et -0.3<ô <0.3 ; Ga0.ioTi0.8oNb2.io07 ; Feo.ioTio.8oNb 2.iqO7 ; • MxTi2_2xNb10+xO29±ô • in which M is an element whose oxidation state is +III, more particularly M is at least one of the elements chosen from the group consisting of Fe, Ga, Mo, Al, B, and where 0 <x<0.40 et -0.3<ô <0.3 ; Tii_xM1xNb2_yM2yO7_zM3z or LiwTii_xM1xNb2_yM2yO7_zM3zin which M1 and M2 are each at least one element selected from the group consisting of Nb, V, Ta, Fe, Co, Ti, Bi, Sb, As, P, Cr, Mo, W, B, Na, Mg, Ca, Ba, Pb, Al, Zr, Si, Sr, K, Cs and Sn, M1 and M2 may be identical or different from each other, M3 is at least one halogen, and in which 0 <w<5et0<x< let0<y<2etz< 0,3 ; TiNb2O7 ZM3Z or LiwTiNb2O7 ZM3Z in which M3 is at least one halogen, preferably selected from F, Cl, Br, I or a mixture thereof, with 0 < w < 5 and 0 < z < 0.3; • Tii xGexNb^yM'yO^ • M1 is at least one element selected from the group consisting of Nb, V, Ta, Fe, Co, Ti, Bi, Sb, As, P, Cr, Mo, W, B, Na, Mg, Ca, Ba, Pb, Al, Zr, Si, Sr, K, Cs and Sn; • 0 <w<5et0<x<let0<y<2etz< 0,3 ; • Ti, xGcxNb2yM'yO7ZM2Z, LiwTi, xGcxNb2 yM'yO7 ZM2Z, TilxCcxNb2vM' yO7 zM2z, LiwTii xCexNb2_yM1yO7_zM2z in which • M1 and M2 are each at least one element selected from the group consisting of Nb, V, Ta, Fe, Co, Ti, Bi, Sb, As, P, Cr, Mo, W, B, Na, Mg, Ca, Ba, Pb, Al, Zr, Si, Sr, K, Cs, Ce and Sn, • M1 and M2 may be identical or different from each other, • and in which 0 <w<5et0<x<let0<y<2etz< 0,3 ; TiO2; TiOxNy with x<2 and 0 <y<0,2 ; • LiSiTON, tin and silicon-based oxynitrides, and more particularly the formulation SiSno,870i,2oNi,72 and their lithiated forms; • nitrides and oxynitrides of the MOxNy type where M is at least one element chosen from Ge, Si, Sn, Zn, Co, Ni, Cu, Fe or a mixture of one or more of these elements, and where x>=0 and y >=0.3; • Li3 xMxN with M is at least one element chosen from Cu, Ni, Co or a mixture of one or more of these elements and 0 < x < 1; • Li3 xMxN with M being cobalt (Co) and 0 < x < 0.5; Li3 xMxN with M being nickel (Ni) and 0 < x < 0.6; Li3 xMxN with M being copper (Cu) and 0 < x <0.3; • lithium iron phosphate (typical formula LiFePO4); • mixed silicon and tin oxynitrides, with typical formula SiaSnb OyNz with a>0, b>0, a+b<2, 0 <y<4, 0<z<3, appelés aussi SiTON, et en particulier le SiSno,870i,2Ni,72 ; ainsi que les oxynitrures-carbures de formule typique SiaSnbCcOyNz avec a> 0, b>0, a+b<2, 0 <c<10, 0<y<24, 0<z<17; • nitrides of the SixNy type, in particular with x=3 and y=4; SnxNy, in particular with x=3 and y=4, ZnxNy, in particular with x=3 and y=2; Li 3 xMxN with 0 <x<0,5 pour M=Co, 0<x<0,6 pour M=Ni, 0<x<0,3 pour M=Cu; Si3 xMxN4 avec M=Co ou Fe et 0<x<3. • the oxides SnO2, SnO, Li2SnO3, SnSiO3, LixSiOy with x>=0 and 2>y>0, Li4Ti50i2, TiNb2O7, Co3O4, SnB0.6Po.402.9 and TiO2, • Si, Sn, SiO2, SnO2, SiN, SnN and their mixtures, • TiNb2O7 composite oxides comprising between 0% and 10% by mass of carbon, preferably the carbon being chosen from graphene and carbon nanotubes.

[0062] Advantageously, said aforementioned active electrode material PA is used to manufacture an anode.

[0063] Another subject of the invention is a porous electrode capable of being obtained by the method according to the invention. The porous electrode according to the invention comprises at least one active electrode material P and an electronically conductive oxide material, is free of binder, and has a porosity of between 25% and 60% by volume, preferably between 25% and 50%.

[0064] Another object of the invention is a method of manufacturing a device for storing or producing electrical energy, preferably selected from the group formed by: capacitors, supercapacitors, hybrid supercapacitors such as lithium ion hybrid supercapacitors, sodium ion hybrid supercapacitors, sodium ion hybrid supercapacitors potassium, photovoltaic cells, photoelectrochemical cells and batteries such as lithium ion batteries, sodium ion batteries, potassium ion batteries, implementing the method of manufacturing a porous electrode according to the invention or implementing a porous electrode according to the invention.

[0065] Another subject of the invention is a method for manufacturing a device for storing or producing electrical energy, such as a battery, a capacitor, a supercapacitor, a hybrid supercapacitor such as a lithium ion hybrid supercapacitor, a sodium ion hybrid supercapacitor, a potassium ion hybrid supercapacitor, a photoelectrochemical cell, a photovoltaic cell, and in particular a method for manufacturing a lithium ion, sodium ion, or potassium ion battery implementing the method for manufacturing a porous electrode according to the invention, in particular by using, as active electrode material P, an active electrode material PC to manufacture a cathode, and / or by using an active electrode material PA to manufacture an anode.

[0066] In particular, this method lends itself well to the manufacture of batteries, and generally speaking, the battery according to the invention can be designed and dimensioned as a surface-mounted component (a technology commonly abbreviated to "SMT", Surface-Mount Technology), so as to be compatible with microelectronics manufacturing methods, in particular with robotic methods for filling electronic cards known under the term "pick and place".

[0067] Advantageously, said porous electrode is impregnated with an electrolyte, preferably with a phase carrying lithium ions, sodium ions or potassium ions selected from the group formed by: • an electrolyte composed of at least one aprotic solvent and at least one lithium, sodium or potassium salt; • an electrolyte composed of at least one ionic liquid and at least one lithium, sodium or potassium salt; • a mixture of at least one aprotic solvent and at least one ionic liquid and at least one lithium, sodium or potassium salt; • an ionic liquid polymer; • a polymer made ionically conductive by the addition of at least one lithium, sodium or potassium salt; and • a polymer made ionically conductive by the addition of a liquid electrolyte, either in the polymer phase or in the porous structure,

[0068] or by an ionic conductive polymer preferably chosen from polyethylene oxide (PEO), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), poly(propylene carbonate) (PPC), poly(ethylene carbonate) (PEC), poly(vinyl carbonate) (PVC), polyvinylidene fluoride (PVDF), polypropylene glycol (PPG), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly-dimethylsiloxane (PDMS), poly(e-caprolactone) (PCL) and poly(tri methylene carbonate) (PTMC).

[0069] Another object of the invention is a device for storing or producing electrical energy capable of being obtained by the method according to the invention, preferably a battery, preferentially a lithium ion, sodium ion or potassium ion battery capable of being obtained by the method according to the invention.

[0070] Advantageously, the device for storing or producing electrical energy according to the invention is a capacitor, a supercapacitor, a hybrid supercapacitor such as a lithium ion hybrid supercapacitor, a sodium ion hybrid supercapacitor, a potassium ion hybrid supercapacitor, a photovoltaic cell, a photoelectrochemical cell, or a battery such as a lithium ion battery, a sodium ion battery or a potassium ion battery.

[0071] The method according to the invention is particularly well suited to the production of porous electrodes with a thickness greater than 1 μm or even greater than 3 μm, while ensuring low series resistance of the battery.

[0072] Another object of the invention is a device for storing or producing electrical energy, such as a battery, a capacitor, a supercapacitor, a photovoltaic cell, a photoelectrochemical cell, comprising a porous electrode according to the invention or capable of being obtained by the method according to the invention. Detailed description of the invention

[0073] 1. Definitions

[0074] The present invention relates to a porous electrode whose accessible surface, i.e. the external surface of the electrode as well as the interior of the accessible pores of the electrode, is coated with an electronically conductive oxide material. The term "electronically conductive oxide" includes electronically conductive oxides and electronically semiconductive oxides.

[0075] For the purposes of this document, the size of a particle is defined by its largest dimension. The term "nanoparticle" means any particle or object of nanometric size having at least one of its dimensions less than or equal to 400 nm.

[0076] By "ionic liquid" is meant any liquid salt, capable of transporting electricity, differing from all molten salts by a melting temperature below 100°C. Some of these salts remain liquid at room temperature and do not solidify, even at very low temperatures. Such salts are called "ionic liquids at room temperature".

[0077] By "electrolyte" is meant any ionically conductive substance due to the presence of mobile ions; it can be solid without liquid or liquid phase. These ions are preferably Li+, Na+ or K+. A liquid electrolyte can be in the form of a gel. To galvanically separate the electrodes, electrolytes are electronic insulators.

[0078] By “mesoporous” materials is meant any solid which has within its structure pores called “mesopores” having an intermediate size between that of micropores (width less than 2 nm) and that of macropores (width greater than 50 nm), namely a size between 2 nm and 50 nm. This terminology corresponds to that adopted by IUP AC (International Union for Pure and Applied Chemistry), which is a reference for those skilled in the art. The term “nanopore” is therefore not used here, even if the mesopores as defined above have nanometric dimensions within the meaning of the definition of nanoparticles, knowing that pores of a size smaller than that of mesopores are called “micropores” by those skilled in the art.

[0079] A presentation of the concepts of porosity (and the terminology just set out above) is given in the article “Texture of powdered or porous materials” by F. Rouquerol et al., published in the collection “Techniques de l'Ingénieur”, treatise Analysis and Characterization, booklet P 1050; this article also describes the techniques for characterizing porosity, in particular the BET method.

[0080] For the purposes of the present invention, the term "porous layer" means a layer which has pores. The term "mesoporous layer" means a layer which has mesopores. In these layers, the pores and mesopores contribute significantly to the total pore volume; this fact is translated by the expression "Porous / mesoporous layer with porosity greater than X% by volume" used in the present description.

[0081] The term "aggregate" means, according to the IUPAC definitions, a loosely bound assembly of primary particles. In this case, these primary particles are particles having a diameter that can be determined by transmission electron microscopy. An aggregate of aggregated primary nanoparticles can normally be destroyed (i.e. reduced to primary particles) in suspension in a liquid phase under the effect of ultrasound, according to a technique known to those skilled in the art.

[0082] The term "agglomerate" means, according to the IUPAC definitions, a strongly bound assembly of primary particles or aggregates.

[0083] 2. Preparation of primary particle suspensions

[0084] The porous electrodes according to the invention are produced from a colloidal suspension of primary particles of at least one active electrode material P, a paste comprising primary particles of at least one active electrode material P or of a preparation comprising primary particles of at least one active electrode material P. For the purposes of the invention, preparation means a mixture comprising primary particles of at least one active electrode material P, and optionally at least one additive such as a binder or a plasticizer. This preparation may be in the form of powders, in pasty form or as a colloidal suspension.

[0085] In an even more preferred embodiment of the invention the particles are prepared directly to their primary size by precipitation, Pechini synthesis, pyrolytic spraying, hydrothermal or solvothermal synthesis. ; Hydrothermal or solvothermal synthesis makes it possible to obtain particles, preferably nanoparticles with a very narrow size distribution, called "monodisperse particles". The size of these non-aggregated or non-agglomerated powders / particles is called the primary size.

[0086] Primary particles with an average primary diameter D50 of between 400 nm and 10 pm, preferably between 700 nm and 3 pm, more preferably between 800 nm and 1 pm can be used in the process according to the invention. These are particles that are easy to produce and use. They can advantageously be used in the form of powders, preferably ground or attrited in order to reduce the particle size distribution. They can also be used in the form of a suspension or paste.

[0087] Primary particles with an average primary diameter D50 of between 2 nm and 400 nm, preferably between 5 nm and 300 nm, more preferably between 10 nm and 250 nm may be used, in particular in the form of a suspension or paste. The use of such primary particles with an average primary diameter D50 of between 2 nm and 400 nm, preferably between 5 nm and 300 nm, more preferably between 10 nm and 250 nm promotes, during the subsequent process steps, the formation of an interconnected mesoporous network with electronic and ionic conduction, thanks to the "necking" phenomenon and advantageously makes it possible to reduce the temperature of the heat treatments, in particular the consolidation (sintering) temperature of the layers according to the invention.

[0088] Additives such as binders may also be added to the preparation, paste or suspension of particles to facilitate the production of deposits, green strips or extrudates, particularly thick deposits without cracks.

[0089] On these primary particles, preferably monodisperse, of at least one active electrode material P, a layer of at least one precursor of an electronically conductive oxide material is formed by any appropriate means.

[0090] 3. Mixture comprising at least one precursor of an electrically conductive oxide material electronics and a colloidal suspension or paste comprising primary particles, of at least one active electrode material P - Formation of a layer of at least one precursor of an electronically conductive oxide material on the primary particles, of at least one active electrode material P.

[0091] Very advantageously, the layer of electronically conductive oxide material can be obtained in different ways and by any appropriate means, in particular by bringing the colloidal suspension, the paste or the preparation comprising primary particles, of at least one active electrode material P into contact with a liquid phase comprising at least one precursor of an electronically conductive oxide material followed by the transformation of said precursor(s) of an electronically conductive material into an electronically conductive material.

[0092] More generally, with the techniques for producing the coating of at least one precursor of an electronically conductive oxide material indicated here, only the accessible surfaces of the primary particles are covered with at least one active electrode material P.

[0093] The formation of a layer of at least one precursor of an electronically conductive oxide material on the primary particles of the suspension, paste or preparation is advantageously carried out in the presence of complexing agents, such as polyvinylpyrrolidone (PVP) so as to facilitate the complexation of the precursor(s) on the surface of the primary particles.

[0094] This method is simple, rapid and easy to implement. Advantageously, said precursor(s) of the electronically conductive material is chosen from organic salts containing one or more metallic elements capable, after heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, of forming an electronically conductive oxide. The electronically conductive oxide may optionally comprise at least one doping element. These metallic elements, preferably these metallic cations, may advantageously be chosen from tin, zinc, indium, gallium, molybdenum or a mixture of two or three or four or five of these elements. The organic salts are preferably chosen from:

[0095] - an alcoholate of at least one metallic element capable, after heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, to form an electronically conductive oxide,

[0096] - a nitrate of at least one metallic element capable, after heat treatment such that a calcination, preferably carried out in air or in an oxidizing atmosphere, forms an electronically conductive oxide,

[0097] - an oxalate of at least one metallic element capable, after heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, to form an electronically conductive oxide, and

[0098] - an acetate of at least one metallic element capable, after heat treatment such that a calcination, preferably carried out in air or in an oxidizing atmosphere, of form an electronically conductive oxide.

[0099] To obtain a layer of an electronically conductive material, preferably an electronically conductive oxide material, from an alcoholate, a nitrate, an oxalate or an acetate, on primary particles of at least one active electrode material P, the colloidal suspension, the paste or the preparation comprising said primary particles can be brought into contact with a solution rich in precursor of the desired electronically conductive material.

[0100] It is the mixture of this colloidal suspension, paste or preparation comprising primary particles of an active electrode material P and at least one precursor of an electronically conductive oxide material, which is then used for the manufacture of a dried porous layer or an extrudate, and of an electrode according to the invention. The mixture of this colloidal suspension, paste or preparation comprising primary particles of an active electrode material P and at least one precursor of an electronically conductive oxide material is hereinafter referred to as the "mixture according to the invention". Advantageously, the mixture according to the invention is in the form of a colloidal suspension, a paste (ink) or a preparation.

[0101] 4. Manufacture of a porous layer

[0102] The electrode according to the invention can be manufactured in several ways. A first method for manufacturing an electrode according to the invention comprises the application of a mixture comprising the precursor(s) of an electronically conductive oxide material and the colloidal suspension, paste comprising primary particles of at least one active electrode material P, on a substrate to form a layer, then the drying of said layer in order to obtain a porous layer. This sequence comprising the application of this mixture on a substrate to form a layer and its drying can be repeated several times in order to increase the thickness of the porous layer. The final thickness of this porous layer is advantageously less than or equal to 5 mm, preferably less than or equal to 1 mm, preferably between approximately 1 μm and approximately 500 μm.The thickness of this porous layer is advantageously less than 500 μm, preferably between approximately 2 μm and approximately 400 μm, preferably between 2 μm and 300 μm, more preferably between 3 μm and 200 μm. Generally, the mixture according to the invention in the form of a colloidal suspension or paste is deposited on a substrate, by any appropriate technique, and in particular by electrophoresis, by extrusion, by additive manufacturing (in English "robocasting"), by the ink-jet printing process hereinafter "ink-jet", by spraying, by flexographic printing, by a coating process, preferably using a doctor blade (technique known in English as "doctor blade" or "tape casting"), by roller coating (in English "roll coating"), by curtain coating (in English "curtain coating"), by extrusion through a die in the form of a . slot (in English "slot-die"), or by dipping-withdrawal (in English "dip-coating").

[0103] In order for the mixture according to the invention to have a viscosity adapted to the coating techniques usually used for the manufacture of electrodes, and thus to be able to be deposited on a substrate, it is advantageous to use the mixture according to the invention in the form of a colloidal suspension or paste having a dry extract of less than 30% by mass.

[0104] According to the invention, the porous layer can be deposited by the inkjet printing process (called "ink-jet" in English) or by a coating process, and in particular by the coating process by dipping (called "dip-coating" in English), by roller coating (called "roll coating" in English), by curtain coating (called "curtain coating" in English), by coating through a slot-die (called "slot-die" in English), or by scraping (called "doctor blade" in English), and this from a mixture according to the invention in the form of a fairly concentrated suspension comprising at least one precursor of an electronically conductive oxide material and particles of the active material P.

[0105] The porous electrode layer can also be deposited by electrophoresis, but then a mixture according to the invention is advantageously used in the form of a less concentrated suspension comprising at least one precursor of an electronically conductive oxide material and particles of the active material P.

[0106] The methods of depositing a mixture according to the invention by electrophoretic means, by extrusion, by additive manufacturing, by the dip coating process, by inkjet, by roller coating, by curtain coating, by scraping or through a slot-shaped die are simple, safe, easy to implement, to industrialize and making it possible to obtain a homogeneous final porous layer. Electrophoretic deposition makes it possible to deposit layers uniformly over large surfaces with high deposition speeds. The coating techniques, in particular those mentioned above, make it possible to simplify the management of the baths compared to electrophoretic deposition techniques because the suspension does not become depleted in particles during deposition. Deposition by inkjet printing makes it possible to make localized deposits.

[0107] Thick-film porous layers, preferably having a thickness greater than 30 μm, can be produced in a single step by roller coating, curtain coating, slot die coating, or scraping (i.e. with a doctor blade) or even extrusion.

[0108] The technique for depositing the mixture according to the invention in the form of a colloidal suspension or paste (ink), and the conduct of the deposition process must be compatible with the viscosity of the colloidal suspension or paste (ink) used, and vice versa.

[0109] When the technique for forming a layer according to the invention requires the use of a substrate, the latter is advantageously an intermediate substrate or a substrate which can serve as a current collector.

[0110] 4.1 Substrate capable of acting as a current collector

[0111] In a first embodiment, said substrate is a substrate capable of acting as an electric current collector and is advantageously compatible with the heat treatments used in the method according to the invention. The substrate may advantageously be a metal substrate or an electronically conductive carbon substrate, in particular based on graphite, graphene and / or carbon nanotubes. Said substrate on which the mixture according to the invention is deposited in the form of a colloidal suspension or paste (ink) ensures the current collector function for the electrode. The mixture according to the invention in the form of a colloidal suspension or a paste (ink) may be deposited on one or both faces of the substrate, in particular not using the deposition techniques indicated above.

[0112] The current collector within the electrochemical devices employing electrodes according to the invention may be a substrate that is stable in the operating potential range of the electrochemical device. Within the batteries employing electrodes according to the invention, the current collector must be a substrate that is stable in a potential range, preferably between 2.5 V and 5 V for the cathode and between 0 V and 2.5 V for the anode, relative to the potential of the lithium. Advantageously, a metal substrate is chosen, for example a metal strip (i.e. a laminated metal sheet). The substrate may in particular be made of tungsten, molybdenum, chromium, titanium, tantalum, zirconium, niobium, stainless steel, or an alloy of two or more of these materials. Such metal substrates are quite expensive and can significantly increase the cost of the battery.Tungsten, molybdenum, chromium, titanium, tantalum, zirconium, niobium, stainless steel and their alloys are particularly resistant to high-temperature heat treatments; they are therefore particularly well suited as a sinterable electrode substrate. The purpose of using these heat-resistant substrates is to be able to sinter deposits, preferably thin ones, directly onto the substrate.

[0113] It is also possible to coat this substrate capable of acting as an electric current collector, with a conductive or semiconductive oxide before depositing the mixture according to the invention in the form of a colloidal suspension or paste (ink), which makes it possible in particular to protect less noble substrates such as copper, nickel, aluminum and carbon, in particular in the form of graphite. These less noble substrates can thus be used as electrode substrates, in particular due to their cost. It may be a conductive carbon sheet (typically graphite), a metal sheet, or a metallized non-metal sheet (i.e. coated with a metal layer). The substrate is preferably chosen from copper, nickel, molybdenum, tungsten, tantalum, chromium, niobium, zirconium, titanium foils, and alloy foils comprising at least one of these elements. Stainless steel can also be used. These substrates have the advantage of being stable over a wide potential range and resistant to heat treatments.

[0114] Copper, nickel, molybdenum and their alloys are preferably used as an anodic substrate. Carbon-based substrates, in particular in the form of graphite, based on nickel-chromium alloys, stainless steels, chromium, titanium, aluminum, tungsten, molybdenum, tantalum, zirconium, niobium or alloys containing at least one of these elements are preferably used as an electric current collector substrate for cathodes. These anodic and / or cathodic substrates may or may not be coated with an electrochemically conductive and inert layer. Such layers may be produced by deposition of nitrides, carbides, graphites, gold, palladium and / or platinum.

[0115] The mixture according to the invention in the form of a colloidal suspension or paste (ink) can be deposited on one or both sides of the substrate capable of acting as a current collector. The layer deposited on this substrate is then dried so as to obtain a porous layer comprising an active electrode material P as well as at least one precursor of an active electronically conductive material.

[0116] The transformation of the precursor(s) of an electronically conductive oxide material into an electronically conductive oxide material is then carried out on this dried porous layer initially deposited on one or both faces of the substrate capable of acting as a current collector.

[0117] 4.2 Intermediate substrate

[0118] According to a second embodiment, the mixture according to the invention is not deposited in the form of a colloidal suspension or paste comprising an active electrode material P as well as at least one precursor of an active electronically conductive material (ink) on a substrate capable of acting as an electric current collector, but on an intermediate substrate, which is typically used temporarily.

[0119] In this embodiment, the mixture according to the invention in the form of a colloidal suspension or paste (ink) is deposited on one face of the intermediate substrate, so as to be able to subsequently easily detach the layer obtained from this intermediate substrate.

[0120] In particular, it is possible to deposit, from the mixture according to the invention in the form of a suspension or paste comprising at least one precursor of an electronically conductive oxide material and primary particles of active electrode material P, preferably from a concentrated suspension comprising at least one precursor of an electronically conductive oxide material and particles of active electrode material P (i.e. less fluid, preferably pasty), fairly thick layers (called "green sheet" in English). These thick layers can be deposited by any suitable means, in particular by the inkjet printing process, by extrusion, by additive manufacturing, by spraying, by flexographic printing, by a coating process, preferably by doctor blade, by roller coating, by curtain coating, by extrusion through a slot-shaped die, or by dipping.

[0121] The particle deposition processes, by the dip coating process, by the inkjet printing process, by roller coating, by curtain coating, through a slot-shaped die, by extrusion, by additive manufacturing, by spraying, by flexographic printing or by doctoring coating are simple, safe processes, easy to implement, to industrialize and allowing to obtain a homogeneous deposition. Inkjet printing allows to deposit the mixture according to the invention in a localized manner, in the same way as the doctoring deposits under mask. Thick layers can be obtained in a single step by the techniques of roller coating, curtain coating, slot-die, by dip, by extrusion, by additive manufacturing or by doctoring.

[0122] Said intermediate substrate may be a flexible substrate, which may be a polymer sheet, for example polyethylene terephthalate, abbreviated PET. In this second embodiment, the deposition step is advantageously carried out on one face of said intermediate substrate in order to facilitate the subsequent separation of the layer from its substrate. In this second embodiment, the layer is separated from its substrate after drying and before any high-temperature heat treatment. The thickness of the layer after drying is advantageously less than or equal to 5 mm, advantageously between approximately 1 μm and approximately 600 μm. The thickness of the layer after drying is advantageously less than 500 μm, preferably between approximately 3 μm and approximately 400 μm, preferentially between 3 μm and 300 μm.

[0123] In said second embodiment, the method for manufacturing an electrode for an electrochemical device such as a battery uses an intermediate substrate preferably made of polymer (such as PET) and results in a strip called a “green strip”. After drying, this green strip is then separated from its substrate; it then forms self-supporting plates or sheets (the term “plate” is used hereinafter, regardless of its thickness).

[0124] The transformation of the precursor(s) of an electronically conductive oxide material into an electronically conductive oxide material is then carried out on these self-supporting porous plates or sheets. 4.3 without substrate

[0125] A second method of manufacturing an electrode according to the invention comprises the formation by extrusion of an extrudate, i.e. a self-supporting porous plate, from a mixture which may be in the form of a colloidal suspension, a paste or a preparation (powder or fluid having a viscosity adapted to the targeted extrusion technique).

[0126] Advantageously, the extrudate can be produced from a solvent-free mixture; this makes it possible to avoid any subsequent drying step of the self-supporting porous layer obtained. This second manufacturing method advantageously makes it possible to obtain a self-supporting porous plate, without the use of a substrate.

[0127] The porous electrode according to the invention can be obtained according to this second manufacturing method comprising the following steps where:

[0128] (2a) at least one precursor of an electrically conductive oxide material is supplied electronics, and a preparation comprising primary particles of at least one active electrode material P,

[0129] (2b) said precursor(s) of an electrically conductive oxide material are mixed electronics and said preparation comprising primary particles of at least one active electrode material P supplied in step (2a), so as to form a mixture,

[0130] (2c) an extrudate is formed from the mixture obtained at the end of step (2b), by extrusion,

[0131] (2d) the transformation of the precursor(s) of an oxide material is carried out electronic conductor made of electronically conductive oxide material,

[0132] (2e) said extrudate comprising an electrically conductive oxide material is consolidated electronics obtained at the end of step (2d), by heat and / or mechanical treatment, preferably by sintering, to obtain a porous, preferably mesoporous, electrode,

[0133] it being understood that steps (2d) and (2e) can be carried out during the same heat treatment.

[0134] Additives such as binders and / or plasticizers may also be added to the preparation comprising primary particles of at least one active electrode material P to facilitate the production of extrudates, i.e. raw strips hereinafter called self-supporting porous plates during the extrusion process.

[0135] According to this variant, the extrusion is carried out by means of a piston or screw extruder by pushing the preparation into a die which ensures the geometry of the section of the desired extrudate. The operating conditions of the extrusion, such as the temperature and the pressure, are advantageously chosen according to the nature of the components of the mixture used.

[0136] The transformation of the precursor of an electronically conductive oxide material into an electronically conductive oxide material is then carried out on these porous plates. self-propelled.

[0137] 5. Transformation of the precursor(s) of an electrically conductive oxide material electronics present in the dried porous layer of electronically conductive oxide material

[0138] The dried porous layer or self-supporting porous plate comprising an active electrode material P as well as at least one precursor of an active electronically conductive material obtained according to the first or second manufacturing method according to the invention, is subjected to a heat treatment, preferably in air or in an oxidizing atmosphere, at a temperature sufficient to transform the precursor(s) of the electronically conductive oxide material of interest into an electronically conductive oxide material.Thus, zones of active material of electrode P are formed, coated with a coating of the electronically conductive material, preferably a coating of an electronically conductive oxide material, more preferably SnO2, ZnO doped with aluminum (ZnO:Al, preferably having a Zn:Al molar ratio of between 1:0.015 and 1:0.05), In2O3, Ga2O3, MoO3, SrMoO3, a coating comprising a mixture of two of these oxides such as indium-tin oxide corresponding to a mixture of indium oxide (In2O3) and tin oxide (SnO2), a mixture of three of these oxides, a mixture of four of these oxides, a mixture of five of these oxides or a mixture of six of these oxides, throughout the internal volume of the electrode as well as on the surface, in a perfectly distributed manner.

[0139] This heat treatment, preferably carried out in an oxidizing atmosphere, can make it possible to eliminate the organic constituents, i.e. to carry out debinding. This heat treatment can also make it possible, depending on the nature of the active electrode material P used and the temperature used to transform the precursor(s) of the electronically conductive oxide material of interest into an electronically conductive oxide material, to consolidate the porous layer or plate, as will be explained in detail in the following section.

[0140] With regard to the prior art and in particular a porous electrode comprising a carbonaceous coating on and inside the pores of the electrode as presented in application WO 2021 / 220174, the presence of zones of active electrode material P coated at least in part with a coating of the electronically conductive oxide material, preferably coated with a coating of the electronically conductive oxide material, throughout the internal volume of the electrode as well as on the surface, in a perfectly distributed manner, gives the electrode better electrochemical performance at high temperature, and makes it possible to significantly increase the stability of the electrode. The fact of using this singular three-dimensional structure comprising zones of active electrode material P coated at least in part with a coating of an electronically conductive oxide material throughout the internal volume of the electrode as well as on the surface, preferably comprising areas of active electrode material P coated with a coating of the electronically conductive oxide material throughout the internal volume of the electrode as well as on the surface, provides, among other things, better performance to the final electrode. Indeed, the presence of areas of active electrode material P coated at least in part with a coating of an electronically conductive oxide material, preferably coated with a coating of the electronically conductive oxide material throughout the internal volume of the electrode as well as on the surface, makes it possible to improve the final properties of the electrode, in particular to improve the voltage resistance of the electrode, its temperature resistance, to improve the electrochemical stability of the electrode, in particular when it is in contact with a liquid electrolyte, to reduce the polarization resistance of the electrode, even when the electrode is thick.It is particularly advantageous to use an electronically conductive material in the form of an oxide, in particular of the type In2O3, SnO2, ZnO doped with aluminum (ZnO:A1, preferably having a Zn:Al molar ratio of between 1:0.015 and 1:0.05), Ga2O3, MoO3, SrMoO3, or a mixture of one or more of these oxides or these doped oxides, in the volume of the electrode, when the electrode is thick, and / or when the active materials of the porous layer are too resistive.

[0141] The electrode according to the invention is porous, preferably mesoporous, and its specific surface area is advantageously large. Increasing the specific surface area of ​​the electrode multiplies the exchange surfaces, and consequently, the power of the battery, but it also accelerates parasitic reactions. The presence of these electronically conductive coatings in the form of oxide in the volume of the electrode will make it possible to block these parasitic reactions.

[0142] Furthermore, due to the very large specific surface area, the effect of these electronically conductive coatings in oxide form on the electronic conductivity of the electrode will be much more pronounced than in the case of a conventional electrode, where the specific surface area is less, even if the deposited conductive coatings have a small thickness. These electronically conductive oxide coatings, arranged in the volume of the electrode and on the surface of the porous layer, give the electrode excellent electronic conductivity, in particular when the porous layer is made from an active electrode material that is not very electronically conductive.This layer of electronically conductive oxide material makes it possible to improve the electrical conductivity of the electrode while limiting the dissolution of the electrode and also makes it possible to increase the power of the battery; this is all the more true since the coating layer of electronically conductive oxide material of the zones of active material of electrode P has a small thickness.

[0143] This is essentially the singular structure of the porous electrode developed according to the method according to the invention comprising zones of active electrode material P coated with a coating of the electronically conductive oxide material throughout the internal volume of the electrode as well as on the surface which makes it possible to improve the final properties of the electrode, in particular to obtain thick electrodes without increasing the internal resistance of the electrode.

[0144] This coating of an electronically conductive oxide material throughout the internal volume of the electrode coating zones of active electrode material P typically has a thickness of less than 10 nm, preferably less than 7 nm, preferably less than 5 nm, more preferably between 5 nm and 3 nm and even more preferably less than 3 nm. The coating of the electronically conductive oxide material throughout the internal volume of the electrode advantageously has an optimal thickness; this coating must be sufficiently thick to improve electronic conduction and sufficiently thin so as not to hinder ionic conduction inside the electrode, and ultimately so as not to degrade the performance of the device for storing or producing electrical energy such as a battery. Furthermore, this coating gives the electrode good electronic conduction due to the large specific surface area of ​​the electrode.

[0145] Advantageously, said electronically conductive material may be an electronically conductive oxide material, preferably chosen from:

[0146] - tin oxide (SnO2), zinc oxide doped with aluminum (ZnO:A1), preferably having a Zn:Al molar ratio of between 1:0.015 and 1:0.05, indium oxide (In2O3), gallium oxide (Ga2O3), molybdenum oxide (MoO3), molybdenum and strontium oxide (SrMoO3), a mixture of two of these oxides such as indium-tin oxide corresponding to a mixture of indium oxide (In2O3) and tin oxide (SnO2), a mixture of three of these oxides, a mixture of four of these oxides, a mixture of five of these oxides or a mixture of six of these oxides,

[0147] - doped oxides based on zinc oxide, the doping preferably being gallium (Ga) and / or aluminium (Al) and / or boron (B) and / or beryllium (Be), and / or chromium (Cr) and / or cerium (Ce) and / or titanium (Ti) and / or indium (In) and / or cobalt (Co) and / or nickel (Ni) and / or copper (Cu) and / or manganese (Mn) and / or germanium (Ge) and / or molybdenum (Mo),

[0148] - doped oxides based on indium oxide, the doping preferably being tin (Sn), and / or gallium (Ga) and / or chromium (Cr) and / or cerium (Ce) and / or titanium (Ti) and / or indium (In) and / or cobalt (Co) and / or nickel (Ni) and / or copper (Cu) and / or manganese (Mn) and / or germanium (Ge) and / or molybdenum (Mo),

[0149] - doped tin oxides, the doping preferably being arsenic (As) and / or fluorinated (F) and / or nitrogen (N) and / or niobium (Nb) and / or phosphorus (P) and / or antimony (Sb) and / or aluminum (Al) and / or titanium (Ti), and / or gallium (Ga) and / or chromium (Cr) and / or cerium (Ce) and / or indium (In) and / or cobalt (Co) and / or nickel (Ni) and / or copper (Cu) and / or manganese (Mn) and / or germanium (Ge) and / or molybdenum (Mo),

[0150] - doped oxides based on molybdenum oxide, the doping preferably being at least lithium (Li) and / or sodium (Na) and / or potassium (K) and / or beryllium (Be) and / or magnesium (Mg) and / or calcium (Ca) and / or scandium (Sc) and / or titanium (Ti) and / or vanadium (V) and / or chromium (Cr) and / or manganese (Mn) and / or iron (Fe) and / or cobalt (Co) and / or nickel (Ni) and / or copper (Cu) and / or zinc (Zn) and / or gallium (Ga) and / or germanium (Ge) and / or arsenic (As) and / or rubidium (Rb) and / or caesium (Cs) and / or yttrium (Y) and / or zirconium (Zr), and / or strontium (Sr) and / or niobium (Nb) and / or tritium (T) and / or rhenium and / or iridium (Ir) and / or platinum (Pt) and / or gold (Au) and / or mercury (Hg) and / or lead (Pb) and / or bismuth (Bi).

[0151] 6. Consolidation of the porous layer comprising an active electrode material P and an electronically conductive oxide material, to obtain a porous, preferably mesoporous, electrode

[0152] The self-supporting porous layers or porous plates can then be heat-treated, preferably in an oxidizing atmosphere, if necessary, in order to remove the organic constituents. The self-supporting porous layers or porous plates can then be consolidated. This consolidation can be carried out by pressing and / or heat treatment, i.e. by a heat treatment (heating), by a heat treatment preceded by a mechanical treatment, and possibly by a thermomechanical treatment, typically thermocompression. In a very advantageous embodiment of the invention, this treatment leads to a partial coalescence of the primary particles together, in particular via the presence of the coating of an electronically conductive oxide material; this phenomenon is called "necking" or "neck formation".It is characterized by the partial coalescence of two particles in contact, which remain separated but connected by a (constricted) neck. Lithium ions and electrons are mobile within these necks and can diffuse from one particle to another without encountering grain boundaries. The particles are welded together to ensure the conduction of electrons from one particle to another.

[0153] Thus, from the primary particles of active electrode material P and the electronically conductive oxide material, a rigid mesoporous film is formed, without organic binder, forming a three-dimensional network with high ionic mobility and electronic conduction; this network comprises interconnected pores, preferably mesopores. This porous layer, preferably mesoporous, thus obtained is perfectly well suited to the impregnation of the pores of the electrode by an ionically conductive material, which enters into the depth of the open porous structure of the layer.

[0154] The temperature required to obtain "necking" depends on the material; given the diffusive nature of the phenomenon that leads to necking, the duration of the treatment depends on the temperature. This process can be called sintering; depending on its duration and temperature, a more or less pronounced coalescence (necking) is obtained, which has an impact on the porosity. It is thus possible to obtain an electrode with a desired porous or mesoporous ceramic structure of controlled porosity while maintaining a perfectly homogeneous channel size. During this thermomechanical or thermal treatment, the electrode layer will be freed from any organic constituent and residue (such as the liquid phase of the particle suspension, binders and possible surfactant products): it becomes an inorganic (ceramic) layer.

[0155] These porous electrodes or plates thus sintered have a thickness advantageously less than or equal to 5 mm, preferably between approximately 1 μm and approximately 500 μm. The thickness of the porous plate after sintering is advantageously between 2 μm and 400 μm, preferably between 2 μm and 300 μm, more preferably between 3 μm and 200 μm.

[0156] According to the second embodiment and in order to obtain a porous electrode arranged on a substrate capable of acting as a current collector, an electrically conductive sheet is also provided, covered on at least one of its faces, preferably on both of its faces, with a thin layer of conductive glue (loaded with graphite) or a sol-gel type deposit loaded with conductive particles. Said thin layers preferably have a thickness of less than 1 μm. This electrically conductive sheet may be a metal strip or a graphite sheet.

[0157] When said electrically conductive sheet is metallic, it is preferably a rolled sheet, i.e. obtained by rolling. The rolling may optionally be followed by a final annealing, which may be a softening annealing (total or partial) or recrystallization annealing, according to the terminology of metallurgy. It is also possible to use a sheet obtained by electrolytic deposition, for example an electrodeposited copper sheet or an electrodeposited nickel sheet.

[0158] This electrically conductive sheet is then placed on a plate or inserted between two plates obtained previously after consolidation (i.e. sintering). The assembly is then advantageously pressed so that said intermediate thin layer of conductive glue promotes the adhesion of the plate to the substrate and forms a plate / substrate or plate / substrate / plate assembly to obtain a rigid, single-piece subassembly.

[0159] One of the advantages of the second embodiment is that it allows the use of inexpensive substrates such as aluminum foils, copper foils or graphite. In fact, these strips do not withstand heat treatments to consolidate the deposited layers; gluing them to the plates after their heat treatment also prevents their oxidation.

[0160] The plate / substrate or plate / substrate / plate subassemblies thus obtained may be used in the manufacture of an electrochemical device such as a battery.

[0161] Optionally, the porous electrode according to the invention, preferably the self-supporting porous plate, can be impregnated with an ionic conductive phase, i.e. comprising at least one ionic conductive material, such as an ionic conductive polymer or an ionic liquid polymer. This ionic conductive material can also exhibit electronic conduction. The ionic conductive materials can be of different natures. They can be liquid, in the form of gels, but also solid. Impregnation with solid ionic conductors is advantageously carried out by using ionic conductors in the molten state or dissolved in a solvent which will subsequently be evaporated.The ionically conductive phase may comprise or be an ionically conductive polymer preferably selected from polyethylene oxide (PEO), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), poly(propylene carbonate) (PPC), poly(ethylene carbonate) (PEC), poly(vinyl carbonate) (PVC), polyvinylidene fluoride (PVDF), polypropylene glycol (PPG), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polydimethylsiloxane (PDMS), poly(e-caprolactone) (PCL) and poly(trimethylene carbonate) (PTMC).

[0162] The presence of an ionically conductive polymer in the pores of the porous electrode, preferably in the pores of the self-supporting porous plate, gives it better mechanical rigidity. The use of a porous electrode according to the invention impregnated with an ionically conductive polymer within an energy storage or production device, such as a battery, makes it possible to increase its lifetime.

[0163] Optionally, a layer which is electronically insulating and which has good ionic conductivity can be deposited above the porous electrode according to the invention; its thickness is typically of the order of 0.5 nm to 20 nm, preferably less than 5 nm, and even more preferably less than 2 nm.

[0164] Said ionically conductive and electronically insulating layer may be of inorganic or organic nature. More particularly, among the inorganic layers, for example, an oxide, a phosphate or a borate conducting lithium ions may be used, and among the organic layers, polymers may be used (for example, PEO possibly containing lithium salts, or a sulfonated tetrafluoroethylene copolymer such as Nafion™, CAS No. 31175-20-9). This ionically conductive and electronically insulating layer must be stable in contact with the electrode on which it is deposited. On a cathode, the use of borate, which conducts lithium ions, will be preferred.

[0165] This ionic conductive and electronic insulating layer makes it possible to limit the dissolution of ions from the electrode and their migration towards the electrolyte, knowing that in LiMn2O4 electrodes manganese risks dissolving in certain liquid electrolytes, particularly at high temperature.

[0166] When the electrode according to the invention is covered with an ionic conductive layer, it is the latter which will mainly ensure the protection functions, as described above (in particular preventing the dissolution of the electrode).

[0167] To summarize, the presence of zones of active electrode material P coated with a coating of the electronically conductive oxide material throughout the internal volume of the electrode and on the surface of the porous electrode according to the invention, allows at least the increase in electronic conductivity and, depending on the nature of the electronically conductive oxide material, can advantageously allow the protection of the electrode against its dissolution in the electrolyte at high temperature.Either these two effects are obtained with only the singular arrangement of the electronically conductive oxide material in the entire internal volume and on the surface of the electrode according to the invention, or this particular arrangement of the electronically conductive oxide material in the entire internal volume of the electrode according to the invention is not sufficient to obtain the two effects in which case it is possible to deposit on and inside the pores of the electrode according to the invention, for example, an ionically conductive and electronically insulating layer; to obtain additional protection at high temperature.

[0168] According to the first and second embodiments, a porous electrode according to the invention is obtained, arranged on a metal substrate serving as an electronic current collector or located on either side of a metal substrate serving as an electronic current collector. The electrode / substrate / electrode subassemblies thus obtained, by the first or second embodiment, can be used in the manufacture of an electrochemical device such as a battery, and in particular a microbattery.A heat-sealing assembly can also be carried out by stacking and heat-pressing the entire structure of the electrochemical device (such as a battery and in particular a microbattery); in this case, a multi-layer stack is assembled comprising a first anode according to the invention, its metal substrate, a second anode according to the invention, a solid electrolyte layer or an electrolytic separator, a first cathode according to the invention, its metal substrate, a second cathode according to the invention, a new solid electrolyte layer or a new electrolytic separator, and so on.

[0169] This electrode / substrate / electrode subassembly can be used to manufacture dis electrochemical positives such as batteries (and in particular microbatteries). Whatever the method of making the electrode / substrate / electrode subassembly, the electrolyte film or the electrolytic separator is then deposited on the latter. The necessary cuts are then made to make a battery with several elementary cells, then the subassemblies are stacked (typically in "head to tail" mode) and thermocompression is carried out to weld the anodes and cathodes together at the level of the solid electrolyte.

[0170] Alternatively, the cuts necessary to produce a battery with several elementary cells can be made, before the deposition of an electrolyte film or an electrolytic separator, on each anode / substrate / anode and cathode / substrate / cathode subassembly. Then the anode / substrate / anode subassemblies and / or the cathode / substrate / cathode subassemblies are coated with an electrolyte film or an electrolytic separator, then the subassemblies are stacked and thermocompression is carried out to weld the anodes and the cathodes together at the level of the electrolyte film or the electrolytic separator, and if necessary, the stack obtained is impregnated with an electrolyte, preferably a phase carrying lithium, sodium or potassium ions.

[0171] In the two variants which have just been presented, the thermocompression welding can be carried out at a relatively low temperature, in particular when the electrodes according to the invention are impregnated with an ionic conductive material which may be an ionic conductive polymer or an ionic liquid polymer. As a result, no oxidation of the metal layers of the substrate is observed.

Claims

1. Claims Method for manufacturing a porous electrode, in particular for devices for storing or producing electrical energy, said electrode being a porous layer comprising at least one active electrode material P and an electronically conductive oxide material, said electrode being free of binder, having a porosity of between 25% and 60% by volume, preferably between 25% and 50%, said manufacturing method being characterized in that: (a) at least one precursor of an electronically conductive oxide material, a colloidal suspension, a paste or a preparation comprising primary particles of at least one active electrode material P, and optionally a substrate is provided, knowing that said substrate can be a substrate capable of acting as an electric current collector, or be an intermediate substrate, (b) mixing said precursor(s) of an electronically conductive oxide material and said colloidal suspension or said paste or said preparation comprising primary particles, of at least one active electrode material P supplied in step (a), so as to form a mixture, (c) a layer is formed from the mixture obtained at the end of step (b), by a process selected from the group consisting of: electrophoresis, a printing process, preferably inkjet printing or flexographic printing, a coating process, preferably by doctor blade, roller, curtain, dip-shrink, or through a slot-shaped die, or an extrudate is formed from the mixture obtained at the end of step (b) by extrusion, (d) said layer obtained in step (c) is dried so as to obtain a dried layer, where appropriate, said dried layer is separated from its intermediate substrate after the drying step, and / or a heat treatment is carried out, preferably in an oxidizing atmosphere, of said dried layer obtained following the drying of step (d) or of said extrudate obtained at the end of step (c); (e) the transformation of the precursor(s) of an electronically conductive oxide material into an electronically conductive oxide material is carried out, (f) consolidating said layer or said extrudate obtained at the end of step (e), by thermal and / or mechanical treatment, preferably by sintering, to obtain a porous, preferably mesoporous, electrode, it being understood that steps (d), (e) and (f), preferably steps (e) and (f), can be carried out during the same heat treatment step.

2. A method of manufacturing a porous electrode according to claim 1, characterized in that step (b) is carried out by bringing the colloidal suspension of the paste supplied in step (a) comprising primary particles of at least one active electrode material P into contact with a liquid phase comprising at least one precursor of said electronically conductive oxide material, and in that said transformation of the precursor(s) of an electronically conductive oxide material into an electronically conductive oxide material during step (e) is carried out by heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere.

3. A method of manufacturing a porous electrode according to any one of the preceding claims, characterized in that after step (f) the pores of said porous electrode are impregnated with an electrolyte, preferably with a phase carrying lithium ions, sodium ions or potassium ions selected from the group formed by: - ​​an electrolyte composed of at least one aprotic solvent and at least one lithium, sodium or potassium salt; - an electrolyte composed of at least one ionic liquid and at least one lithium, sodium or potassium salt; - a mixture of at least one aprotic solvent and at least one ionic liquid and at least one lithium, sodium or potassium salt; - an ionic liquid polymer; - a polymer made ionically conductive by the addition of at least one lithium, sodium or potassium salt;and - a polymer made ionically conductive by the addition of a liquid electrolyte, either in the polymer phase or in the porous structure of the porous electrode, or by an ionically conductive polymer, preferably chosen from polyethylene oxide (PEO), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), poly(propylene carbonate) (PPC), poly(ethylene carbonate) (PEC), poly(vinyl carbonate) (PVC), polyvinylidene fluoride (PVDF), polypropylene glycol (PPG), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polydimethylsiloxane (PDMS), poly(e-caprolactone) (PCL) and poly(tri;

4. methylene carbonate) (PTMC). A method of manufacturing a porous electrode according to any one of the preceding claims, characterized in that said precursor(s) of the electronically conductive oxide material is chosen from organic salts containing one or more metallic elements capable, after heat treatment such as calcination, of forming an electronically conductive oxide, and in that said transformation into an electronically conductive material is a heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, these organic salts preferably being chosen from - an alcoholate of at least one metallic element capable, after heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, of forming an electronically conductive oxide, - a nitrate of at least one metallic element capable, after heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, of forming an electronically conductive oxide, - an oxalate of at least one metallic element capable, after heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, of forming an electronically conductive oxide, and - an acetate of at least one metallic element capable, after heat treatment such as calcination, preferably carried out in air or in an oxidizing atmosphere, of forming an electronically conductive oxide, - and / or in that, preferably, the metallic element is chosen from tin, zinc, indium, gallium, molybdenum or a mixture of two or three or four or five of these elements, and / or in that said electronically conductive oxide material is chosen from: - tin oxide (SnO2), zinc oxide doped with aluminum (ZnO:Al, preferably having a Zn:Al molar ratio of between 1:0.015 and 1:0.05, indium oxide (In2O3), gallium oxide (Ga2O3), molybdenum oxide (MoO3), molybdenum and strontium oxide (SrMoO3), a mixture of two of these oxides such as indium-tin oxide corresponding to a mixture of indium oxide (In2O3) and tin oxide (SnO2), a mixture of three of these oxides, a mixture of four of these oxides, a mixture of five of these oxides or a mixture of six of these oxides, - doped oxides based on zinc oxide, the doping preferably being gallium (Ga) and / or aluminium (Al) and / or boron (B) and / or beryllium (Be), and / or chromium (Cr) and / or cerium (Ce) and / or titanium (Ti) and / or indium (In) and / or cobalt (Co) and / or nickel (Ni) and / or copper (Cu) and / or manganese (Mn) and / or germanium (Ge) and / or molybdenum (Mo), - doped oxides based on indium oxide, the doping preferably being tin (Sn), and / or gallium (Ga) and / or chromium (Cr) and / or cerium (Ce) and / or titanium (Ti) and / or indium (In) and / or cobalt (Co) and / or nickel (Ni) and / or copper (Cu) and / or manganese (Mn) and / or germanium (Ge) and / or molybdenum (Mo), - doped tin oxides, the doping preferably being arsenic (As) and / or fluorine (F) and / or nitrogen (N) and / or niobium (Nb) and / or phosphorus (P) and / or antimony (Sb) and / or aluminum (Al) and / or titanium (Ti), and / or gallium (Ga) and / or chromium (Cr) and / or cerium (Ce) and / or indium (In) and / or cobalt (Co) and / or nickel (Ni) and / or copper (Cu) and / or manganese (Mn) and / or germanium (Ge) and / or molybdenum (Mo), - doped oxides based on molybdenum oxide, the doping preferably being lithium (Li) and / or sodium (Na) and / or potassium (K) and / or beryllium (Be) and / or magnesium (Mg) and / or calcium (Ca) and / or scandium (Sc) and / or titanium (Ti) and / or vanadium (V) and / or chromium (Cr) and / or manganese (Mn) and / or iron (Fe) and / or cobalt (Co) and / or nickel (Ni) and / or copper (Cu) and / or zinc (Zn) and / or gallium (Ga) and / or germanium (Ge) and / or arsenic (As) and / or rubidium (Rb) and / or caesium (Cs) and / or yttrium (Y) and / or zirconium (Zr), and / or strontium (Sr) and / or niobium (Nb) and / or tritium (T) and / or rhenium and / or iridium (Ir) and / or platinum (Pt) and / or gold (Au) and / or mercury (Hg) and / or lead (Pb) and / or bismuth (Bi), and / or in that said P electrode active material is a PC electrode active material selected from the group consisting of: • the oxides LiMn2O4, Lii+xMn2xO4 with O < x < 0.15, LiCoO2, LiNiO2, LiMn j5Nio>504, LiMn|XNi0xxXxO4 where X is selected from Al, Fe, Cr, Co, Rh, Nd, other rare earths such as Sc, Y, Lu, La, Ce, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and where 0 < x < 0.1, LiMn2xMxO4 with M = Er, Dy, Gd, Tb, Yb, Al, Y, Ni, Co, Ti, Sn, As, Mg or a mixture of these compounds and or 0 < x < 0.4, LiFeO2, LiM:ni / 3Nii / 3Coi / 302jLiNio.8Coo 15AI0.05O 2jLiAlxMn2xO4with0< x < 0.15, LiNii / xCoi / yMni / zO2 with x+y+z =10 ; LixMyO2 where 0.6 <y<0.85; 0<x+y<2; et M est choisi parmi Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Sn, and Sb ou un mélange de ces éléments ; Lii.2oNb0.2oMno.6o02 ; Lii+xNbyMezApO2 where Me is at least one transition metal chosen from: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Te, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, and where 0.6 <x<l; 0<y<0.5; 0.25<z<l; avec A Me et A Nb, et 0<p<0.2 ; LixNby aNaMzbPbO2cFc where 1.2 <x<1.75; 0<y<0.55; 0.1<z<l; 0<a<0.5; 0<b<l; 0<c<0.8; et où M, N, et P sont chacun au moins un des éléments choisi dans le groupe constitué par Ti, Ta, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Zr, Y, Mo, Ru, Rh, Ce et Sb ; Lii.25Nbo.25Mn0.5o02 ; Li1.3Nbo.3Mn0.4o02; Li1.3Nbo.3Fe0.4o02; Li13 Nbo.43Nio.2702; Lii 3Nbo.43Coo,2702; Li14Nbo.7Mno.53O7; LixNi0.7Mn0.6Oy where 0.00 <x<1.52; 1.07<y<2.4 ; Lii.2Ni0.2Mn0.6O 2; LiNixCoyMni_x_yO2 where 0 < x and y < 0.5; LiNixCezCoyMni x yO2 where 0 < x and y < 0.5 and 0 < z; the phosphates LiFePO4, LiMnPO4, LiCoPO4, LiNiPO4, Li3V2 (PO4)3j Li2MPO4F with M = Fe, Co, Ni or a mixture of these different elements, LiMPO4F with M = V, Fe, T or a mixture of these different elements; the phosphates of formula LiMM'PO4, with M and M' (M M') selected from Fe, Mn, Ni, Co, V such as LiFexCoi xPO4et where 0 < x < 1; FeogCoo iOF; FeF3; LiMSO4F with M = Fe, Co, Ni, Mn, Zn, Mg; titanium oxysulfides (TiOySz with z=2-y and 0.3 <y<l), les oxysulfures de tungstène (WOySz avec 0.6<y<3 et 0.1<z<2), CuS, CuS2, LixV2O5avec 0 < x < 2, LixV3O8avec 0 < x < 1,7, LixTiS2 avec 0 < x < 1, les oxysulfures de titane et de lithium LixTiOySzavec z=2-y, 0,3<y<l et 0 < x < 1, LixWOySzavec z=2-y, 0,3<y<l et 0 < x < 1, LixCuS avec 0 < x < 1, LixCuS2 avec 0 < x < 1, and / or in that said active electrode material P is an active electrode material PA selected from the group formed by: • Li4Ti50i2, Li4Ti5 xMxOi2 with M = V, Zr, Hf, Nb, Ta and 0 < x < 0.25; • niobium oxides and mixed oxides of niobium with titanium, germanium, cerium or tungsten, and preferably in the group formed by: Nb2O5±ô, Nb12WO33±ô, Nb14W3O44±ô, Nb18W16O93± ô, Nb16W5O ​​55±ôô with 0 < ô < 2, LiNbO3, • TiNb2O7±ô, LiwTiNb2O7 with w>0, Tii xM'xNb2 yM2yO7±ô or Li wTii_xM1xNb2 yM2yO7±ô in which M1 and M2 are each at least one element selected from the group consisting of Nb, V, Ta, Fe, Co, Ti, Bi, Sb, As, P, Cr, Mo, W, B, Na, Mg, Ca, Ba, Pb, Al, Zr, Si, Sr, K, Cs and Sn, M1 and M2 being the same or different from each other, and in which 0 < w < 5 and 0 < x < let0 <y<2et0<ô< 0,3 ; • LaxTii 2XNb2+xO7 where 0 <x<0.5 ; • MxTi1_2XNb2+xO7±ô • in which M is an element whose oxidation state is +III, more particularly M is at least one of the elements chosen from the group consisting of Fe, Ga, Mo, Al, B, and where 0 <x<0.20 et -0.3<ô <0.3 ; Ga0.10Ti0.80Nb2.10O 7 ; Fe0.10Ti0.80Nb2.10O? ; * MxTi2_2xNbi0+xO29±ô • in which M is an element whose oxidation state is +III, more particularly M is at least one of the elements chosen from the group consisting of Fe, Ga, Mo, Al, B, and where 0 <x<0.40 et -0.3<ô <0.3 ; • Tii_xM1xNb2_yM2yO7_zM3z or LiwTii_xM1xNb2_yM2yO7_zM3zin which • M1 and M2 are each at least one element selected from the group consisting of Nb, V, Ta, Fe, Co, Ti, Bi, Sb, As, P, Cr, Mo, W, B, Na, Mg, Ca, Ba, Pb, Al, Zr, Si, Sr, K, Cs and Sn, • M1 and M2 may be identical or different from each other, M3 is at least one halogen, and in which 0 <w<5et0<x< let0<y<2etz< 0,3 ; TiNb2O7 ZM3Z ou LiwTiNb2O7 zMy dans lesquels M3 est au moins un halogène, de préférence choisi parmi F, Cl, Br, I ou un mélange de ceux-ci, avec 0<w<5et0<z< 0,3 ; • TiixGexNb^yM'yO?^ • M1 is at least one element selected from the group consisting of Nb, V, Ta, Fe, Co, Ti, Bi, Sb, As, P, Cr, Mo, W, B, Na, Mg, Ca, Ba, Pb, Al, Zr, Si, Sr, K, Cs and Sn; • 0 <w<5et0<x<let0<y<2etz< 0.3; • Ti1_xGexNb2_yM1yO7_zM2z, LiwTi, sGcsNb2yM'yO7ZM3Z, Ti1_xCexNb2_yM1yO7_zM2Z, LiwTi, sCcsNb2 yM 'yO7 ZM2Z, in which • M1 and M2 are each at least one element selected from the group consisting of Nb, V, Ta, Fe, Co, Ti, Bi, Sb, As, P, Cr, Mo, W, B, Na, Mg, Ca, Ba, Pb, Al, Zr, Si, Sr, K, Cs, Ce and Sn, • M1 and M2 may be identical or different from each other, • and in which 0 <w<5et0<x<let0< y < 2 et z < 0,3 ; TiO2; TiOxNy with x<2 and 0 <y<0,2 ; LiSiTON, tin and silicon based oxynitrides, and more particularly the formulation SiSn0j870ij2oNij72 and their lithiated forms; nitrides and oxynitrides of the MOxNy type where M is at least one element chosen from Ge, Si, Sn, Zn, Co, Ni, Cu, Fe or a mixture of one or more of these elements, and where x>0 and y >0.3; Li3 xMxN with M is at least one element selected from Cu, Ni, Co or a mixture of one or more of these elements and 0 < x < 1;• Li3 xMxN with M being cobalt (Co) and 0 < x < 0.5; Li3 xMx N with M being nickel (Ni) and 0 < x < 0.6; Li3_xMxN with M being copper (Cu) and 0 < x < 0.

3. • lithium iron phosphate, with the typical formula LiFePO 4; • mixed silicon and tin oxynitrides, with the typical formula SiaSnbOyNz with a>0, b>0, a+b<2, 0 <y<4, 0<z<3, appelés aussi SiTON, et en particulier le SiSn 0.87O12N172 ; ainsi que les oxynitrures-carbures de formule typique SiaSnbCcOyNz avec a> 0, b>0, a+b<2, 0 <c<10, 0<y<24, 0<z<17; • les nitrures de type SixNy, en particulier avec x=3 et y=4 ; SnxNy, en particulier avec x=3 et y=4, ZnxNy, en particulier avec x=3 et y=2 ; Li3 xMxN avec 0<x<0,5 pour M=Co, 0<x<0,6 pour M=Ni, 0<x<0,3 pour M=Cu; Si3.xMxN4 avec M=Co ou Fe et 0<x<3.• the oxides SnO2, SnO, Li2SnO3, SnSiO3, LixSiOy with x>=0 and 2>y>0, Li4Ti50i2, TiNb2O7, Co3O4, SnBOj6Po,4 O2j9 and TiO2, Si, Sn, SiO2, SnO2, SiN, SnN and their mixtures, • the composite oxides TiNb2O7 comprising between 0% and 10% by mass of carbon, preferably the carbon being chosen from graphene and carbon nanotubes.

5. Method for manufacturing a porous electrode according to any one of the preceding claims, characterized in that said porous electrode obtained at the end of step (f) has a specific surface area of ​​between 10 m2 / g and 500 m2 / g and / or a thickness of between 2 pm and 400 pm, preferably between 2 pm and 300 pm, more preferably between 3 pm and 200 pm.

6. A method of manufacturing a porous electrode according to any one of claims 1 to 4, characterized in that when said substrate is an intermediate substrate, said layer is separated from said intermediate substrate in step (d) after drying of said layer, to form a porous plate.

7. A method of manufacturing a porous electrode according to any one of the preceding claims, characterized in that said colloidal suspension or paste or preparation supplied in step (a) comprises organic additives, such as ligands, stabilizers, binders or residual organic solvents, and the heat treatment of step (d), preferably under an oxidizing atmosphere, of said dried layer or said extrudate obtained at the end of step (c) according to any one of the preceding claims, or of said porous plate according to claim 6, is carried out, it being understood that this heat treatment and steps (d), (e) and (f), preferably steps (e) and (f), can be carried out during the same heat treatment step.

8. Porous electrode obtainable by the method according to any one of claims 1 to 7.

9. Method for manufacturing a device for storing or producing electrical energy, implementing the method for manufacturing a porous electrode according to one of claims 1 to 7, or implementing a porous electrode according to claim 8.

10. Method according to claim 9, characterized in that said device for storing or producing electrical energy is selected from the group formed by: capacitors, supercapacitors, hybrid supercapacitors such as lithium ion hybrid supercapacitors, sodium ion hybrid supercapacitors, potassium ion hybrid supercapacitors, photovoltaic cells, photoelectrochemical cells and batteries such as lithium ion batteries, sodium ion batteries, potassium ion batteries.

11. A method according to claim 9 or 10, wherein said device is a lithium ion battery and the method for manufacturing a porous electrode according to claim 4 is carried out using, as the electrode active material P, a PC electrode active material to manufacture a cathode, and / or using a PA electrode active material to manufacture an anode.

12. A method of manufacturing a battery implementing the method of manufacturing a porous electrode according to one of claims 1 to 7, or implementing a porous electrode according to claim 8, wherein said porous electrode is impregnated with an electrolyte, preferably with a phase carrying lithium ions, sodium ions,

13.

14. of potassium ions selected from the group formed by: - an electrolyte composed of at least one aprotic solvent and at least one lithium, sodium or potassium salt; - an electrolyte composed of at least one ionic liquid and at least one lithium, sodium or potassium salt; - a mixture of at least one aprotic solvent and at least one ionic liquid and at least one lithium, sodium or potassium salt; - an ionic liquid polymer; - a polymer made ionically conductive by the addition of at least one lithium, sodium or potassium salt; and - a polymer made ionically conductive by the addition of a liquid electrolyte, either in the polymer phase or in the porous structure, or by an ionically conductive polymer preferably chosen from polyethylene oxide (PEO), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), poly(propylene carbonate) (PPC), poly(ethylene carbonate) (PEC), poly(vinyl carbonate) (PVC), polyvinylidene fluoride (PVDF), polypropylene glycol (PPG), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polydimethylsiloxane (PDMS), poly(e-caprolactone) (PCL) and poly(tri methylene carbonate) (PTMC). Device for storing or producing electrical energy capable of being obtained by the method according to any one of claims 9 to 12. Device for storing or producing electrical energy according to claim 13, characterized in that this device for storing or producing electrical energy is a capacitor, a supercapacitor, a hybrid supercapacitor such as a lithium ion hybrid supercapacitor, a sodium ion hybrid supercapacitor, a potassium ion hybrid supercapacitor, a photovoltaic cell, a photoelectrochemical cell, or a battery such as a lithium ion battery, a sodium ion battery or a potassium ion battery.