Process for manufacturing a porous electrode, and battery containing such an electrode

Abstract

The present invention relates to a porous electrode for use in electrical energy storage or production devices, such as a lithium ion battery. Said porous electrode is a porous layer comprising at least an active electrode material P and an electronic conductive oxide material.

Description

[0001] DESCRIPTION

[0002] Title: METHOD FOR MANUFACTURING A POROUS ELECTRODE, AND BATTERY CONTAINING SUCH AN ELECTRODE

[0003] Technical field of the invention

[0004] The invention relates to energy storage or production devices. More specifically, it relates to electrodes that can be used 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 that can be impregnated with an ionic conductive phase such as a solid electrolyte without a liquid phase or a liquid electrolyte.

[0005] The invention also relates to a method for preparing such a porous electrode which uses aggregates or agglomerates of nanoparticles of an 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.

[0006] State of the art

[0007] Lithium-ion batteries offer 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; a review is given in the book "Advances in Lithium-Ion Batteries" (ed. W. van Schalkwijk and B. Scrosati), published in 2002 (Kluever Academic / Plenum Publishers).

[0008] There is a growing need for very small rechargeable batteries that can be integrated on electronic boards; these electronic circuits can be used in many areas, for example in cards for securing transactions, in electronic labels, in implantable medical devices, in various micromechanical systems.

[0009] 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 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.

[0010] There is also a growing need for intermediate-sized rechargeable batteries for various stand-alone and portable devices (e.g., mobile phones, laptops, power tools, intermittent-use kitchen appliances).

[0011] In all these applications, the ability to quickly recharge the battery is a highly valued feature. Likewise, these batteries must not present a risk of thermal runaway. And finally, it is desirable that they be able to operate over a wide temperature range.

[0012] 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 pm and 15 pm in diameter.

[0013] These deposition techniques, particularly 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 electronic conductive materials. To produce microbatteries, it is desirable to have a smaller thickness for each constituent layer of the microbattery.

[0014] 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 electrode thicknesses and their porosity on their discharge regime (power) and energy density. Binder-free mesoporous electrode layers for lithium-ion batteries can be deposited by electrophoresis; this is known from WO 2019 / 215 407 (l-TEN). They can be impregnated with a liquid electrolyte, but their electrical resistivity remains quite high.

[0015] To increase the low electronic conductivity of electrodes, especially when these electrodes are thick or made from electrode active materials with low electronic conductivity, a certain amount of electronically conductive material, such as carbon black, is generally added to the electrode active material particles. Ideally, the electronically conductive particles should be available at any 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.

[0016] In practice, it is very difficult to control the arrangement of carbon black within the electrodes. Moreover, with the increasing use of smaller and smaller active material particles, these problems are even more prevalent. A non-uniform distribution of 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 state-of-charge imbalances will be all the more pronounced as the current density is high. These imbalances therefore 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 electrode pores more difficult.

[0017] 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 carbon coating; this is known from WO 2021 / 220 174 (l-TEN). The presence of this carbon 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 carbon electronically conductive coating on the electrode is expensive and difficult to implement.

[0018] 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 disadvantages of the prior art mentioned above.

[0019] More specifically, the problem that the present invention seeks to solve is to provide a method for manufacturing porous electrodes having high, homogeneous electronic conductivity and controlled pore density which is simple, safe, fast, easy to implement, and inexpensive.

[0020] 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,

[0021] Another object of the invention is to provide electrodes for batteries capable of operating at high temperatures without reliability problems and without risk of fire.

[0022] 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.

[0023] 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.

[0024] Yet another aim 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.

[0025] Objects of the invention 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 (l-TEN).

[0026] 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 and 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.

[0027] This porous, preferably mesoporous, entirely solid layer, without organic components, is obtained from agglomerates and / or aggregates of primary nanoparticles of at least one active electrode material and at least one precursor of an electronically conductive oxide material. The sizes of the primary particles constituting these agglomerates and / or aggregates are of the order of a nanometer or tens of nanometers, and the agglomerates and / or aggregates contain at least four primary particles.

[0028] Said substrate may be, in a first embodiment, a substrate capable of acting as an electric current collector, or be, in a second embodiment, an intermediate, temporary substrate which will be explained in more detail below.

[0029] Using agglomerates of a few tens or even hundreds of nanometers in diameter rather than primary, non-agglomerated particles, each of which has a size of around one or ten nanometers, allows for increased deposit thicknesses. However, the agglomerates must remain small to form a continuous mesoporous film during heat treatment of the layer. If the agglomerates are too large, this hinders their sintering and we observe the formation of two distinct porosities in the layer: a porosity between agglomerates and a porosity inside the agglomerates.

[0030] After sintering, a porous, preferably mesoporous, layer or plate is obtained, without carbon black or organic binders, in which all the primary nanoparticles are welded together (by the necking phenomenon, known elsewhere) to form a continuous mesoporous network characterized by unimodal porosity. 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. Furthermore, after sintering, the porous, preferably mesoporous, layer is perfectly adherent to the metal substrate on which it was deposited or transferred (in the case of an initial deposit carried out on an intermediate substrate).

[0031] Heat treatments carried out at high temperatures to sinter the nanoparticles together allow the electrode to be completely dried and all traces of water or solvents or other organic additives (stabilizers, binders) adsorbed on the surface of the active material particles to be removed. The high-temperature heat treatment (sintering) may be preceded by a lower-temperature heat treatment (debinding) to dry the electrode and to remove traces of water or solvents or other organic additives (stabilizers, binders) adsorbed on the surface of the active material particles; this debinding may be carried out in an oxidizing atmosphere.

[0032] Depending on the sintering time and temperature, it is possible to adjust the porosity of the final electrode. Depending on the energy density requirements, the latter can be adjusted within a range of 25% to 60% porosity.

[0033] In all cases, the power density of the electrodes thus obtained remains extremely high due to the porosity, preferably due to the mesoporosity. Furthermore, regardless of the size of the mesopores in the active material (knowing that after sintering the notion of nanoparticle 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.

[0034] 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 is significant. 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.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 material, throughout the internal volume of the electrode as well as on the surface, in a perfectly distributed manner.

[0035] The coating of an electronically conductive oxide material according to the invention is advantageously made of SnC>2, ZnO doped with aluminum (ZnO: Al, preferably having a Zn: Al molar ratio of between 1: 0.015 and 1: 0.05), MoOa, SrMoCh, I^Ch, Ga2O3, or indium-tin oxide.

[0036] 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.

[0037] This thickness is measured by any appropriate technique, in particular by transmission electron microscopy.

[0038] Indeed, as explained above, the method according to the invention, which necessarily involves a step of forming a layer from agglomerated nanoparticles of electrode material (active material) and at least one precursor of an electronically conductive oxide material, causes the nanoparticles 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 well suited to the application of a surface treatment, by gas or liquid means, or of an impregnation which enters into the depth of the open porous structure of the layer.

[0039] A first subject of the invention is a method for manufacturing a porous electrode, in particular for devices for storing or producing electrical energy, such as a battery, said electrode being a porous layer comprising at least one active electrode material P and an electronically conductive oxide material deposited on a substrate, said electrode being free of binder, having a porosity of between 25% and 60% by volume, preferably between 25% and 50%, and pores with an average diameter of less than 100 nm, said manufacturing method being characterized in that:

[0040] (a) a substrate, at least one precursor of an electronically conductive oxide material, and a colloidal suspension or a paste comprising aggregates or agglomerates of primary nanoparticles, of at least one active electrode material P, with an average primary diameter Dso of between 2 nm and 400 nm, preferably between 2 nm and 100 nm, and more preferably between 2 nm and 60 nm, are provided, said aggregates or agglomerates having an average diameter Dso of between 50 nm and 900 nm, and preferably between 100 nm and 800 nm, knowing that said substrate may be a substrate capable of acting as an electric current collector, or be an intermediate substrate,

[0041] (b) mixing said precursor(s) of an electronically conductive oxide material and said colloidal suspension or said paste comprising aggregates or agglomerates of primary nanoparticles, of at least one active electrode material P supplied in step (a), so as to form a mixture,

[0042] (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, an additive manufacturing process, extrusion, 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,

[0043] (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 drying step (d),

[0044] (e) the transformation of the precursor(s) of an electronically conductive oxide material into an electronically conductive oxide material is carried out, so that said dried layer comprises said electronically conductive oxide material,

[0045] (f) said layer is consolidated, by thermal and / or mechanical treatment, preferably by sintering, to obtain a porous, preferably mesoporous, electrode, it being understood that steps (e) and (f) can be carried out during the same thermal treatment. The method according to the invention can comprise, in step (e), in step (f) or between steps (e) and (f), a thermal treatment of said dried layer, preferably in an oxidizing atmosphere.

[0046] 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 formed by: o an electrolyte composed of at least one aprotic solvent and at least one lithium, sodium or potassium salt; o an electrolyte composed of at least one ionic liquid and at least one lithium, sodium or potassium salt; o a mixture of at least one aprotic solvent and at least one ionic liquid and at least one lithium, sodium or potassium salt; o an ionic liquid polymer; o a polymer made ionically conductive by the addition of at least one lithium, sodium or potassium salt;and o 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 methylene carbonate) (PTMC).;

[0047] The lithium ion-carrying phase may comprise a mixture of several ionic liquids. Advantageously, the ionic liquid may be a cation of the 1-Ethyl-3-methylimidazolium type (also called EMI+) and / or n-propyl-n-methylpyrrolidinium (also called PYRi3 +) and / or n-butyl-n-methylpyrrolidinium (also called PYRiY), associated with anions of the bis(trifluoromethanesulfonyl)imide (TFSI") and / or bis(fluorosulfonyl)imide (FS I ") type. To form an electrolyte, a lithium salt such as LiTFSI can be dissolved in the ionic liquid which serves as solvent or in a solvent such as y-butyrolactone. y-butyrolactone prevents the crystallization of ionic liquids inducing a wider operating temperature range of the latter, in particular at low temperatures. The phase carrying sodium or potassium ions can comprise a mixture of several ionic liquids. The ionic liquid can be as described above. To form an electrolyte, a sodium salt such as NaTFSI can be used instead of LiTFSI in a sodium ion battery, or a potassium salt such as KTFSI can be used instead of LiTFSI in a potassium ion battery.The lithium, sodium or potassium ion-carrying phase may comprise an ionic liquid polymer, such as a poly(1-vinyl-3-alkyl-imidazolium) or a poly(1-vinyl-N-alkyl-pyrrolidinium).

[0048] In step (c) the formation of a layer can be done on one or both sides of the substrate.

[0049] Advantageously, 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, in particular after consolidation, a porous plate.

[0050] 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.

[0051] Advantageously, step (b) is carried out by bringing the colloidal suspension or paste supplied in step (a) comprising aggregates or agglomerates of primary nanoparticles, 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.

[0052] 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.

[0053] These organic salts are preferably 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,

[0054] - 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,

[0055] - 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

[0056] - 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 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.

[0057] The metallic element may comprise at least one doping element.

[0058] Advantageously, said porous layer obtained at the end of step (f) has a specific surface area of ​​between 10 m 2 / g and 500 m 2 / g and / or a thickness between 2 pm and 400 pm, preferably between 2 pm and 300 pm, more preferably between 3 pm and 200 pm.

[0059] Advantageously, said porous electrode obtained at the end of step (f) has a specific surface area of ​​between 10 m 2 / g and 500 m 2 / g and / or a thickness between 2 pm and 20 pm when the substrate is a substrate capable of acting as an electric current collector.

[0060] Advantageously, said porous electrode obtained at the end of step (f) has a specific surface area of ​​between 10 m 2 / g and 500 m 2 / g and / or a thickness of between 25 pm and 500 pm, preferably between 50 pm and 400 pm, when the substrate is an intermediate substrate.

[0061] Advantageously, when said colloidal suspension or paste supplied in step (a) comprises organic additives, such as ligands, stabilizers, binders or residual organic solvents, a heat treatment is carried out, preferably in an oxidizing atmosphere, of said dried layer obtained at the end of step (d) or of said porous plate, it being understood that this heat treatment and steps (e) and / or (f) can be carried out during the same heat treatment.

[0062] Advantageously, said active electrode material P is selected from group (A) formed by: o the oxides LiMri2O4, Ui +x Mn2-xO4 with O < x < 0.15, LiCoCh, LiNiC>2, LiMni.sNio.sC^, LiMni,sNio,5-xXx04 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, LiMn2-xM xO4 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 / 3O2 , LiNi0.8Co0.15AI0.05O2, LiAl x Mn2-xO4 with 0 < x < 0.15, LiNii / x Coi / yMni / z O2 with x+y+z =10; o Li x M y O2 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 ; Li1.20Nbo.20Mno.60O2 ; o Lii+xNbyMe z ApO2 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<1 ; 0<y<0.5; 0.25<z<1 ; avec A Me et A Nb, et 0<p<0.2 ; o LixNby-aNaM z -bPbO2-cF cwhere 1.2 <x<1.75; 0<y<0.55; 0.1 <z<1 ; 0<a<0.5; 0<b<1 ; 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 ; o Li1.25Nbo.25Mno.50O2 ; Li1.3Nbo.3Mno.40O2 ; Li1.3Nbo.3Feo.40O2 ; Li1.3Nbo.43Nio.27O2 ;

[0063] Li1.3Nb0.43Co0.27O2; Li1.4Nbo.2Mno.53O2; o LixNi0.2Mn0.eOy where 0.00 <x<1.52; 1.07<y<2.4 ; Li1.2Nio.2Mno.6O2 ; o LiNi x Co y Mni-x-yO2 where 0 < x and y < 0.5; LiNi x This z Co y Mni-x-yO2 where 0 < x and y < 0.5 and 0 < z; o the phosphates LiFePO4, LiMnPÛ4, UCOPO4, LiNiPÛ4, Li3V2(PO4)3, U2MPO4F with M = Fe, Co, Ni or a mixture of these different elements, UMPO4F 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 LiFe xCoi. xPO4 and where 0 < x < 1; o Feo.oCoo OF; FeFs; UMSO4F with M = Fe, Co, Ni, Mn, Zn, Mg; o titanium oxysulphides (TiO y S z with z=2-y and 0.3 <y<1), les oxysulfures de tungstène (WO y S z with 0.6 <y<3 et 0.1 <z<2), CuS, CUS2, LixX^Os avec 0 < x < 2, LixVsOsavec 0 < x < 1 ,7, Li x TiS2 with 0 < x < 1, titanium and lithium oxysulfides LixTiOyS z with z=2-y, 0.3 <y<1 et 0 < x < 1 , Li x WO y S z with z=2-y, 0.3 <y<1 et 0 < x < 1 , LixCuS avec 0 < x < 1 , Li x CuS2 with 0 < x < 1; or in group (B) formed by: transition metal oxides: o Na x M02+ z with M chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z

[0064] < 0.3 and 0 <x < 1 , de préférence 0 < x < 0.44 or 0.44 < x < 0.67 or 0.67

[0065] < x < 1 ; o Na x M u / 2M'v / 2O2+z with u + v = 2 and M, M' chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z< 0.3 and 0 <x < 1 , de préférence 0 < x < 0.44 ou 0.44 < x < 0.67 ou 0.67 < x < 1 ; o Na x M u / 3M'v / 3M” w / 3O 2+ z with u + v + w = ​​3 and M, M', M” chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z < 0.3 and O <x < 1 , de préférence 0 < x < 0.44 ou 0.44 < x < 0.67 ou 0.67 < x < 1 ; o Na x Mn y Neither z Feo.iMgo.i02 with 0.67 < x < 1.0; 0.5 < y < 0.7 and 0.1 < z < 0.3; Prussian blue and / or Prussian blue analogues known by the acronym PBA from the English “Prussian blue analogues”: o Na x M 1 [M 2 '(CN)e]y.nH2O, M 1 being a transition metal or an alloy of transition metals, M 2' being a transition metal, the transition metal and the transition metal alloy being chosen from Fe, Ni, Co and Mn, with 0 < x < 2; y < 1 and 0 < n < 12; the polyanionic compounds: o Na x M2(XO4)3 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W, such that NasX^PCLh; oNa x M3(XO4)2(X2O?) with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o Na x M(X2O?) with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o Na x M2(XO4)2F3 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o Na x M2(XO4)2F3-yO y with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and

[0066] O.07 < y < 0.12 and X = P, S, As, Si, Mo or W; oNa x M2C>2(XO4)2F with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X =

[0067] P, S, As, Si, Mo or W; o Na xMXO4 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; or in the group (C) formed by: transition metal oxides: o KxMCh+z with M chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z

[0068] < 0.3 and 0 <x < 1 , de préférence 0 < x < 0.44 or 0.44 < x < 0.67 or 0.67

[0069] < x < 1 ; o K x Mu / 2M'v / 2O2+z with u + v = 2 and M, M' chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z< 0.3 and 0 <x < 1 , de préférence 0 < x < 0.44 ou

[0070] O.44 < x < 0.67 or 0.67 < x < 1; oK XMU / 3M'V / 3M”W / 3O2+Z with u + v + w = ​​3 and M , M', M” chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z< 0.3 and O <x < 1 , de préférence 0 < x < 0.44 ou 0.44 < x < 0.67 ou 0.67 < x < 1 ; o KxMnyNizFeo.1Mgo.1O2 avec 0.67 < x < 1.0; 0.5 < y < 0.7 et 0.1 < z < 0.3 ; le bleu de prusse (prussian blue) et / ou les analogues de bleu de prusse connu(s) sous le sigle PBA de l’anglais « prussian blue analogs » : o K x M 1 [M 2 '(CN)6]y.nH2O, M 1 being a transition metal or an alloy of transition metals, M 2 ' being a transition metal, the transition metal and the transition metal alloy being chosen from Fe, Ni, Co and Mn, , with 0 < x < 2; y < 1 and 0 < n < 12; the polyanionic compounds: o K X M2(XÛ4)3 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W, such as Na3V2(PO4)s; o K X M3(XO4)2(X2O?) with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X =

[0071] P, S, As, Si, Mo or W; o K X M(X2O?) with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o K X M2(XO4)2F3 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o K x M2(XO4)2F3-yO y with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and 0.07 < y < 0.12 and X = P, S, As, Si, Mo or W; o K X M2C>2(XO4)2F with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o K x MXO4with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W.

[0072] Advantageously, said aforementioned active electrode material P is used to manufacture a cathode. Advantageously, said active electrode material P is selected from group (D) formed by: o Li4TisOi2, Li4Tis-xM xOi2 with M = V, Zr, Hf, Nb, Ta and 0 < x < 0.25; o niobium oxides and mixed oxides of niobium with titanium, germanium, cerium or tungsten, and preferably in the group formed by: o Nb2O 5±5 , Nbi2WO33±s, Nbi4WsO44±8, NbisWi6O93±8 , NbieWsOss a with 0 s 5 s 2, LiNbO3, o TiNb2C>7±8, Li w TiNb2O7 with w>0, Tii-xM 1 x Nb2-yM 2 yO7±8 or Li w Tii-xM 1 xNb2-yM 2 y O7±8 in which M 1 and M 2 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, M 1 and M 2 which may be the same or different from each other, and in which 0 < w < 5 and 0 < x < 1 and 0 < y < 2 and 0 < 5 < 0.3; o The x Tii-2xNb2+xO7 where 0 <x<0.5 ;

[0073] OM x Til.2xNb 2+xO7±5 o 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<5 <0.3 ; Ga0.10Ti0.80Nb2.10O7 ; Fe0.10Ti0.80Nb2.10O7 ;

[0074] OM x Ti2-2xNbl0 + xO29±5o 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<5 <0.3 ; o Tii-xM 1 x Nb2-yM 2 yO7-zM 3 z or Li w Tii-xM 1 xNb2-yM 2 yO7-zM 3 z in which o M 1 and M 2 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, o M 1 and M 2which may be identical or different from each other, o M 3 is at least one halogen, o and in which 0 < w < 5 and 0 < x < 1 and 0 < y < 2 and z < 0.3; o TiNb2O7-zM 3 z or Li w TiNb2O7- z M 3 z in which M 3 is at least one halogen, preferably selected from F, Cl, Br, I or a mixture thereof, and 0 < z < 0.3 and 0 < w < 0.5; o Tii-xGe x Nb2-yM 1 yO7±z , Li w Tii-xGe x Nb2-yM 1 yO7±z , Tii-xCe x Nb2-yM 1 yO7±z , Li w Tii. xCe x Nb2-yM 1 yO7±z in which o M 1 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; o 0 < w < 5 and 0 < x < 1 and 0 < y < 2 and z < 0.3; o Tii.xGe x Nb2-yM 1 yO7-zM 2 z, Li w Tii. x Ge x Nb2-yM1 yO7-zM 2 z , Tii- x This x Nb2-yM 1 y O7-z M 2 Z , LiwTii- x This x Nb2-yM 1 yO7-zM 2 z , in which o M 1 and M 2 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, o M 1 and M 2 which may be the same or different from each other, o and in which 0 < w < 5 and 0 < x < 1 and 0 < y < 2 and z < 0.3; TiO2; TiO x Ny with x<2 and 0 <y<0,2 ; LiSiTON, les oxynitrures à base d’étain et de silicium, et plus particulièrement la formulation SiSno,870i,2oNi,72 et leurs formes lithiées ; les nitrures et oxynitrures de type MO x N ywhere 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-xM x N 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-xM x N with M being cobalt (Co) and 0 < x < 0.5; Li3-xM x N with M being nickel (Ni) and 0 < x < 0.6; Li3-xM x N with M being copper (Cu) and 0 < x < 0.3; lithium iron phosphate (typical formula LiFePO4); mixed silicon and tin oxynitrides, typical formula Si a SnbO y N z 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; les nitrures de type Si x N y , in particular with x=3 and y=4; Sn x N y, in particular with x=3 and y=4, Zn x N y , in particular with x=3 and y=2; Li3- X M X N with 0 <x<0,5 pour M=Co, 0<x<0,6 pour M=Ni, 0<x<0,3 pour M=Cu; Si3- X M X N4 with M=Co or Fe and 0 <x<3. les oxydes SnO2, SnO, Li2SnO3, SnSiOs, Li x SiO y with x>=0 and 2>y>0, Li4TisOi2, TiNb2O7, CO3O4, SnBo.ePo, 402.9 and TiO2, Si, Sn, SiO2, SnO2, SiN, SnN and mixtures thereof, TiNb2O7 composite oxides comprising between 0% and 10% by mass of carbon, preferably the carbon being chosen from graphene and carbon nanotubes; or in the group (E) formed by: alloys based on Si, Ge, Sn, Sb, Bi or P and alloys of these different compounds MXenes. MXenes constitute a class of 2D materials with stoichiometry of the Mn+iX type n T xwith M a transition metal, preferably chosen from Sc, Ti, V, Cr, Y, Zr, Nb, Mo, Hf, Ta, W and X is chosen from C and / or N and T a surface termination chosen from F, Cl, I, Br, O, S, Se, Te, OH, NH2, 1 < n < 4 conversion anode materials such as o oxides of type G2Ti3O?, G4TisOi2, GTi2(PÛ4)3, G being Na or K o oxides, sulfides, selenides, phosphide of the following elements or their alloys: Si, Ge, Sn, Sb, Bi.

[0075] Advantageously, said aforementioned active electrode material P is used to manufacture an anode.

[0076] Another subject of the invention is a porous electrode, in particular for energy storage or production devices, characterized in that it comprises at least one active electrode material P and an electronically conductive oxide material, in that it is free of binder, in that it has a porosity of between 25% and 60% by volume, preferably between 25% and 50%.

[0077] Another subject of the invention is a porous electrode obtainable by the method according to the invention. Another subject of the invention is a porous electrode obtainable by the method according to the invention, characterized in that the porous electrode comprises at least one active electrode material P and an electronically conductive oxide material, in that it is free of binder, in that it has a porosity of between 25% and 60% by volume, preferably between 25% and 50%.

[0078] Another subject of the invention is a method for 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, potassium ion hybrid supercapacitors, photovoltaic cells, photoelectrochemical cells and batteries such as lithium ion batteries, sodium ion batteries, potassium ion batteries, implementing the method for manufacturing a porous electrode according to the invention or implementing a porous electrode according to the invention.Another subject of the invention is a method of 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 of manufacturing a lithium ion, sodium ion, or potassium ion battery implementing the method of manufacturing a porous electrode according to the invention.

[0079] Advantageously, when the device for storing or producing electrical energy is a lithium ion hybrid supercapacitor or a lithium ion battery, the method for manufacturing the cathode uses the active electrode material P chosen from group (A) or the method for manufacturing the anode uses the active electrode material P chosen from group (D).

[0080] Advantageously, when the electrical energy storage or production device is a sodium ion hybrid supercapacitor or a sodium ion battery, the method for manufacturing the cathode uses the active electrode material P chosen from group (B) or the method for manufacturing the anode uses the active electrode material P chosen from group (E) (where appropriate, G being Na).

[0081] Advantageously, when the device for storing or producing electrical energy is a potassium ion hybrid supercapacitor or a potassium ion battery, the method for manufacturing the cathode uses the active electrode material P chosen from group (C) or the method for manufacturing the anode uses the active electrode material P chosen from group (E) (where appropriate, G being K).

[0082] Advantageously, in the method for manufacturing a lithium ion battery, the method for manufacturing a porous electrode is implemented to manufacture a cathode with the active electrode material P chosen from group (A) or the method for manufacturing an anode is implemented with the active electrode material P chosen from group (D).

[0083] In particular, this method is well suited to the manufacture of batteries, and generally speaking, the battery according to the invention can be designed and sized as a surface-mounted component (a technology commonly abbreviated to "SMT"), so as to be compatible with microelectronics manufacturing methods, in particular with robotic methods for filling electronic cards known as "pick and place".

[0084] 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: o an electrolyte composed of at least one aprotic solvent and at least one lithium, sodium or potassium salt; o an electrolyte composed of at least one ionic liquid and at least one lithium, sodium or potassium salt; o a mixture of at least one aprotic solvent and at least one ionic liquid and at least one lithium, sodium or potassium salt; o an ionic liquid polymer; o a polymer made ionically conductive by the addition of at least one lithium, sodium or potassium salt;and o 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).;

[0085] 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.

[0086] 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. Advantageously, when the device for storing or producing electrical energy is a lithium ion hybrid supercapacitor or a lithium ion battery, the active electrode material P is chosen from group (A) for the cathode active material and / or from group (D) for the anode active material.

[0087] Advantageously, when the electrical energy storage or production device is a sodium ion hybrid supercapacitor or a sodium ion battery, the active electrode material P is chosen from group (B) for the active cathode material and / or from group (E) for the active anode material (where appropriate, G being Na).

[0088] Advantageously, when the device for storing or producing electrical energy is a potassium ion hybrid supercapacitor or a potassium ion battery, the active electrode material P is chosen from group (C) for the active cathode material and / or from group (E) for the active anode material (where appropriate, G being K).

[0089] 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.

[0090] Another subject 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.

[0091] Detailed description of the invention

[0092] 1. Definitions

[0093] 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.

[0094] For the purposes of this document, the size of a particle is defined by its largest dimension. "Nanoparticle" means any particle or object of nanometric size with at least one of its dimensions less than or equal to 400 nm.

[0095] The term "ionic liquid" refers to any liquid salt capable of carrying electricity, differing from all molten salts by a melting point 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 "room temperature ionic liquids". The term "electrolyte" refers to any ionically conductive substance due to the presence of mobile ions; it can be solid without a 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.

[0096] 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 IUPAC (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.

[0097] A presentation of the concepts of porosity (and the terminology just explained above) is given in the article “Texture of powdery or porous materials” by F. Rouquerol et al., published in the collection “Techniques de l'ingénieur”, treatise Analysis and Characterization, fascicule P 1050; this article also describes the techniques for characterizing porosity, in particular the BET method.

[0098] 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.

[0099] The term "aggregate" means, according to the IUPAC definitions, a loosely bound assembly of primary particles. In this case, these primary particles are particles, preferably nanoparticles, 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 nanoparticles) in suspension in a liquid phase under the effect of ultrasound, according to a technique known to those skilled in the art.

[0100] The term "agglomerate" means, according to IUPAC definitions, a strongly bonded assembly of primary particles or aggregates.

[0101] 2. Preparation of nanoparticle suspensions The porous electrodes according to the invention are prepared from a colloidal suspension of clusters and / or agglomerates of nanoparticles or a paste.

[0102] In an even more preferred embodiment of the invention, the nanoparticles are prepared directly at 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 nanoparticles". The size of these non-aggregated or non-agglomerated nanopowders / nanoparticles is called the primary size. It is typically between 2 nm and 400 nm, preferably between 2 nm and 100 nm, and more preferably between 2 nm and 60 nm and is advantageously between 10 nm and 50 nm, preferably between 10 nm and 30 nm; this promotes, during subsequent process steps, the formation of an interconnected mesoporous network with electronic and ionic conduction, thanks to the "necking" phenomenon.

[0103] Additives such as binders can also be added to the nanoparticle suspension (clusters and / or agglomerates of nanoparticles, knowing that these clusters are also in the form of nanoparticles) to facilitate the production of deposits or green strips, in particular thick deposits without cracks.

[0104] On these aggregates and / or agglomerates of primary nanoparticles, 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.

[0105] 3. Mixture comprising at least one precursor of an electronically conductive oxide material and a colloidal suspension or paste comprising aggregates and / or agglomerates of 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 aggregates and / or agglomerates of primary nanoparticles, of at least one active electrode material P.

[0106] 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 or the paste comprising aggregates or agglomerates of primary nanoparticles, 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.

[0107] 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 aggregates or agglomerates of primary nanoparticles are covered with at least one active electrode material P.

[0108] The formation of a layer of at least one precursor of an electronically conductive oxide material on the aggregates and / or agglomerates of the suspension or paste 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 aggregates / agglomerates.

[0109] This method is simple, fast 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:

[0110] - 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,

[0111] - 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,

[0112] - 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

[0113] - 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.

[0114] 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 aggregates or agglomerates of primary nanoparticles, of at least one active electrode material P, the colloidal suspension or paste comprising said aggregates or agglomerates of nanoparticles can be brought into contact with a solution rich in precursor of the desired electronically conductive material.

[0115] It is the mixture of this colloidal suspension or paste comprising aggregates or agglomerates of primary nanoparticles 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 and an electrode according to the invention. The mixture of this colloidal suspension or paste comprising aggregates or agglomerates of primary nanoparticles 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 or a paste (ink).

[0116] 4. Production of a porous layer

[0117] The 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 or paste comprising aggregates or agglomerates of primary nanoparticles 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 between approximately 1 μm and approximately 500 μm.The thickness of this porous layer is advantageously less than 500 pm, preferably between approximately 2 pm and approximately 400 pm, preferably between 2 pm and 300 pm, more preferably between 3 pm and 200 pm. 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 inkjet printing process hereinafter "ink-jet", by spraying, by flexographic printing, by a coating process, preferably with a doctor blade (technique known in English under the term "doctor blade" or "tape casting"), by roll coating (in English "roll coating"), by curtain coating (in English "curtain coating"), by extrusion through a slot-die, or by dip-coating.In order for the mixture according to the invention to have a viscosity suitable for 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.

[0118] According to the applicant's findings, with an average diameter of the nanoparticle aggregates or agglomerates of between 50 nm and 900 nm, preferably between 100 nm and 800 nm (preferably between 100 nm and 400 nm), a mesoporous layer having an average mesopore diameter of between 2 nm and 100 nm is obtained in the subsequent process steps.

[0119] 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 aggregates or agglomerates of nanoparticles of the active material P.

[0120] 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 agglomerates of nanoparticles of the active material P.

[0121] The methods for 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 doctoring or through a slot-shaped die are simple, safe, easy to implement, to industrialize and allowing to obtain a homogeneous final porous layer. Electrophoretic deposition allows to deposit layers uniformly on large surfaces with high deposition speeds. The coating techniques, in particular those mentioned above, allow 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 allows to make localized deposits.

[0122] Thick-film porous layers, preferably having a thickness of between 50 and 400 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 by extrusion.

[0123] 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.

[0124] The substrate is advantageously an intermediate substrate or a substrate which can serve as a current collector.

[0125] 4.1 Substrate capable of acting as a current collector

[0126] 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 by the deposition techniques indicated above.

[0127] The current collector within electrochemical devices employing electrodes according to the invention may be a substrate that is stable within the operating potential range of the electrochemical device. Within batteries employing electrodes according to the invention, the current collector must be a substrate that is stable within 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 lithium potential. 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 electrode substrates that can be sintered. The purpose of using these heat-resistant substrates is to be able to sinter deposits, preferably thin ones, directly onto the substrate. This substrate, which can act as an electric current collector, can also be coated with a conductive or semiconducting 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 because of their cost.It can be a conductive carbon foil (typically graphite), a metal foil, or a metallized non-metal foil (i.e. coated with a layer of metal). 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.

[0128] 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 the electric current collector substrate of cathodes. These anodic and / or cathodic substrates may or may not be coated with a conductive and electrochemically inert layer. Such layers may be produced by deposition of nitrides, carbides, graphites, gold, palladium and / or platinum.

[0129] 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.

[0130] 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 sides of the substrate capable of acting as a current collector.

[0131] 4.2 Intermediate substrate

[0132] 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.

[0133] 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 separate the layer obtained from this intermediate substrate.

[0134] 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 aggregates and / or agglomerates of nanoparticles of active electrode material P, preferably from a concentrated suspension comprising at least one precursor of an electronically conductive oxide material and aggregates and / or agglomerates of nanoparticles of active electrode material P (i.e. less fluid, preferably pasty), fairly thick layers (called "green sheets" 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.

[0135] The nanoparticle deposition processes, by dip coating, by inkjet printing, by roller coating, by curtain coating, through a slot-die, by extrusion, by additive manufacturing, by spraying, by flexographic printing or by doctor blade coating are simple, safe, 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 doctor blade depositions under mask. Thick layers can be obtained in a single step by roller coating, curtain coating, slot-die, by dip coating, by extrusion, by additive manufacturing or by doctor blade.

[0136] Said intermediate substrate may be a flexible substrate, which may be a polymer sheet, for example polyethylene terephthalate, abbreviated as PET. In this second embodiment, the deposition step is advantageously carried out on one side 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.

[0137] 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).

[0138] 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.

[0139] 5. Transformation of the precursor(s) of an electronically conductive oxide material present in the dried porous layer into an electronically conductive oxide material

[0140] 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, 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 electrode material P are formed, coated at least in part with a coating of the electronically conductive material, preferably a coating of an electronically conductive oxide material, more preferably SnC>2, ZnO doped with aluminum (ZnO:Al, preferably having a Zn:Al molar ratio of between 1:0.015 and 1:0.05), I^Ch, Ga2O3, MoOa, SrMoCh, a coating comprising a mixture of two of these oxides such as indium-tin oxide corresponding to a mixture of indium oxide (ln2O3) and tin oxide (SnC>2), 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.

[0141] 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.

[0142] With regard to the prior art and in particular a porous electrode comprising a carbon 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.Using this unique three-dimensional structure comprising 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 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 zones 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 I^Ch, SnC>2, ZnO doped with aluminum (ZnO: Al, preferably having a Zn: Al molar ratio of between 1: 0.015 and 1: 0.05), Ga2O3, MoOa, SrMoOs, 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.

[0143] 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 oxide form in the volume of the electrode will make it possible to block these parasitic reactions. 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 lower, even if the deposited conductive coatings have a small thickness.These electronically conductive oxide coatings, arranged in the volume of the electrode of the porous layer, give the electrode excellent electronic conductivity, particularly when the porous layer is made from electrode active material with low electronic conductivity. 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 when the coating layer of electronically conductive oxide material of the electrode active material zones P has a small thickness.

[0144] It is essentially the singular structure of the porous electrode produced 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.

[0145] This coating of an electronically conductive oxide material throughout the internal volume of the electrode coating areas 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 electrical energy storage or production device such as a battery. Furthermore, this coating gives the electrode good electronic conduction due to the large specific surface area of ​​the electrode.

[0146] Advantageously, said electronically conductive material may be an electronically conductive oxide material, preferably chosen from:

[0147] - tin oxide (SnCh), 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 (ln2O3), gallium oxide (Ga2O3), molybdenum oxide (MoO3), molybdenum and strontium oxide (SrMoCh), a mixture of two of these oxides such as indium-tin oxide corresponding to a mixture of indium oxide (ln2O3) and tin oxide (SnC>2), 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,

[0148] - 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),

[0149] - 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),

[0150] - 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),

[0151] - 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).

[0152] 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.

[0153] 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 on the one hand of the primary nanoparticles in the aggregates, or agglomerates, and on the other hand between neighboring aggregates or agglomerates 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 nanoparticles are welded together to ensure the conduction of electrons from one particle to another. Neighboring aggregates or agglomerates are welded together via the presence of the coating of an electronically conductive oxide material to ensure the conduction of electrons from one aggregate or agglomerate to another. Electronic conduction occurs by two different means, namely by the nanoparticles of active electrode material P (1) welded together and by the neighboring aggregates or agglomerates welded together via an electronically conductive oxide material (2); this is illustrated schematically in Figure 1.

[0154] Thus, from the primary nanoparticles of active electrode material P (1) and the electronically conductive oxide material (2), 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.

[0155] 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 with controlled porosity while maintaining a perfectly homogeneous channel size. During this thermomechanical or thermal treatment, the electrode layer will be freed from all organic constituents and residues (such as the liquid phase of the nanoparticle suspension, binders and possible surfactants): it becomes an inorganic (ceramic) layer.

[0156] 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.

[0157] 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.

[0158] 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 a 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.

[0159] 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.

[0160] One of the advantages of the second embodiment is that it allows the use of inexpensive substrates such as aluminum foil, copper foil or graphite foil. Indeed, these foils do not withstand the heat treatments used to consolidate the deposited layers; gluing them to the plates after their heat treatment also prevents their oxidation.

[0161] The plate / substrate or plate / substrate / plate subassemblies thus obtained may be used in the manufacture of an electrochemical device such as a battery. Optionally, the porous electrode according to the invention, preferably the self-supporting porous plate, may 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 may also exhibit electronic conduction. The ionic conductive materials may be of different natures. They may 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(tri methylene 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 lifespan.

[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 Nation™, 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 a borate conducting 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 LiM^CL electrodes manganese risks dissolving in certain liquid electrolytes, in particular at high temperature. When the electrode according to the invention is covered with an ionic conductive layer, it is the latter which will mainly ensure the protective functions, as described above (in particular preventing the dissolution of the electrode).

[0166] To summarize, the presence of zones of active material of electrode 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 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.

[0167] 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.

[0168] This electrode / substrate / electrode subassembly can be used to manufacture electrochemical devices such as batteries (and in particular microbatteries). Regardless of the method of producing the electrode / substrate / electrode subassembly, the electrolyte film or the electrolytic separator is then deposited on it. The necessary cuts are then made to produce 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.

[0169] 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, 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 resulting stack is impregnated with an electrolyte, preferably a phase carrying lithium, sodium or potassium ions.

[0170] 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.

[0171] EXAMPLES

[0172] Example 1: Production of a mesoporous cathode based on LiMn2O4 according to the invention

[0173] An aqueous suspension of LiMn2O4 nanoparticles was prepared by hydrothermal synthesis according to the method described in the article by Liddle et al. entitled “A new one pot hydrothermal synthesis and electrochemical characterisation of Lii +xMn2-yO4 spinel structured compounds », Energy & Environmental Science (2010) vol.3, page 1339-1346: 14.85 g of UOH.H2O were dissolved in 500 mL of water. 43.1 g of KMnO4 were added to this solution and this liquid phase was poured into an autoclave. While stirring, 28 ml of isobutyraldehyde and water were added until a total volume of 3.54 L was reached. The autoclave was then heated to 180°C and maintained at this temperature for 6 hours. After slow cooling, a black precipitate suspended in the solvent was obtained. This precipitate was subjected to a succession of centrifugation - redispersion steps in water, until an aggregated suspension with a conductivity of approximately 300 pS / cm and a zeta potential of -30 mV was obtained. The obtained aggregates consisted of primary aggregated particles of size 10 to 20 nm.The obtained aggregates had a spherical shape and an average diameter of approximately 150 nm; they were characterized by X-ray diffraction and electron microscopy.

[0174] 1 g of polyvinyl pyrrolidone (abbreviated PVP) with a molar mass of 55,000 g / mol was added to 50 mL of distilled water at 40°C, then 3 g of tin acetate was added to this aqueous PVP solution.

[0175] The LiM^CL suspension was reconcentrated by centrifugation and redispersion of the pellet in the volume of water required to obtain a 16 wt% paste. The volume of this aqueous solution of PVP and tin acetate corresponding to a ratio of 10% by mass of tin acetate to LiMn2O4 and the necessary quantity of water to obtain a final suspension of aggregates with a dry extract of 10% were then added to the suspension of LiMn2O4 nanoparticle aggregates.

[0176] The resulting ink was applied to a 5 μm thick stainless steel (316L) strip. The resulting layer was dried in a temperature-controlled oven. The resulting layer has a thickness of approximately 6 μm.

[0177] This layer was then heat treated at 600 °C for 5 h in air in order, on the one hand, to achieve the transformation of tin acetate, precursor of the electronically conductive oxide material, into SnC>2, i.e. into an electronically conductive oxide material, to eliminate the reaction by-products, and on the other hand, to weld the primary nanoparticles together and to weld the neighboring aggregates together via the presence of the electronically conductive oxide material SnC>2 formed, to improve adhesion to the substrate and to perfect the recrystallization of the LiM^CL. The porous layer thus obtained has an open porosity of approximately 45% by volume with pores of a size between 10 nm and 20 nm.

[0178] Production of a mesoporous anode based on Li4TisOi2 according to the invention

[0179] A suspension of Li4TisOi2 nanoparticles was prepared by glycothermal synthesis: 190 mL of 1,4-butanediol was poured into a beaker, and 4.25 g of lithium acetate was added while stirring. The solution was kept stirring until the acetate was completely dissolved. 16.9 g of titanium butoxide was taken under an inert atmosphere and introduced into the acetate solution. The solution was then stirred for a few minutes before being transferred to an autoclave previously filled with an additional 60 mL of butanediol. The autoclave was then closed and purged with nitrogen for at least 10 minutes. The autoclave was then heated to 300 °C at a rate of 3 °C / min and maintained at this temperature for 2 hours, while stirring. At the end, it was allowed to cool, still stirring.

[0180] A white precipitate was obtained in suspension in the solvent. This precipitate was subjected to a succession of centrifugation and redispersion steps in ethanol to obtain a pure colloidal suspension with low ionic conductivity. It comprised aggregates of approximately 150 nm consisting of 10 nm primary particles. The zeta potential was of the order of -45 mV. The product was characterized by X-ray diffraction and electron microscopy.

[0181] 1 g of polyvinyl pyrrolidone (abbreviated PVP) with a molecular weight of 55,000 g / mol was added to 50 mL of ethanol at 40°C, then 3 g of tin acetate was added to this PVP solution.

[0182] The volume of this PVP and tin acetate solution corresponding to a ratio of 10% by mass of tin acetate to Li4Ti50i2 was then added to the suspension of Li4Ti50i2 nanoparticle aggregates. The ethanol was evaporated until the aggregate suspension had a dry extract of 10%. The ink thus obtained was applied to a 5 μm thick stainless steel strip (316L). The layer obtained was dried in a temperature and humidity controlled oven to avoid the formation of cracks during drying. The ink deposition and drying were repeated to obtain a layer approximately 4 μm thick. This layer was then heat treated at 600 °C for 5 h in air. This heat treatment allows the transformation of tin acetate, precursor of the electronically conductive oxide material, into SnO2, i.e.in electronically conductive oxide material, to eliminate the reaction by-products, and thus to form a porous layer comprising aggregates of Li4TisOi2 nanoparticles coated with a homogeneous coating of SnO2, and to consolidate the layer, i.e. to weld the primary nanoparticles together and to weld the neighboring aggregates together via the presence of the electronically conductive oxide material SnC>2 formed, to improve the adhesion to the substrate of the aggregates of Li4TisOi2 nanoparticles coated with a coating of SnC>2 and to perfect the recrystallization of the Li4TisOi2.

[0183] Manufacture of a battery using a porous cathode and a porous anode according to the invention a. Production of a suspension of U3PO4 nanoparticles

[0184] Two solutions were prepared. 11.44 g of CH3COOU, 2H2O were dissolved in 112 ml of water, then 56 ml of water were added with vigorous stirring to the medium in order to obtain a solution A. 4.0584 g of H3PO4 were diluted in 105.6 ml of water, then 45.6 ml of ethanol were added to this solution in order to obtain a second solution hereinafter called solution B. Solution B was then added, with vigorous stirring, to solution A. The solution obtained, perfectly clear after the disappearance of the bubbles formed during mixing, was added to 1.2 liters of acetone under the action of an Ultraturrax™ type homogenizer in order to homogenize the medium. A white precipitation suspended in the liquid phase was immediately observed.

[0185] The reaction medium was homogenized for 5 minutes and then kept for 10 minutes under magnetic stirring. It was allowed to settle for 1 to 2 hours. The supernatant was discarded and the remaining suspension was centrifuged for 10 minutes at 6000 rpm. Then 300 ml of water was added to resuspend the precipitate (using a sonotrode, magnetic stirring). With vigorous stirring, 125 ml of a 100 g / l sodium tripolyphosphate solution was added to the colloidal suspension thus obtained. The suspension thus became more stable. The suspension was then sonicated using a sonotrode. The suspension was then centrifuged for 15 minutes at 8000 rpm. The pellet was then redispersed in 150 ml of water. Then the suspension obtained was centrifuged again for 15 minutes at 8000 rpm and the pellets obtained redispersed in 12 mL of water.

[0186] Agglomerates of approximately 100 nm consisting of primary U3PO4 particles of 10 nm were thus obtained in suspension in water. b. Production on the anode and cathode layers previously developed of a porous inorganic layer from the suspension of U3PO4 nanoparticles previously described in part a).

[0187] Thin porous layers of U3PO4 were then coated onto the surface of the anode and cathode previously prepared from the previously obtained suspension of U3PO4 nanoparticles, to obtain a layer with a thickness of approximately 3 μm. This layer was air-dried at 120°C to remove any trace of organic residues, and then it was calcined at 350°C for one hour in air. c. Construction of an electrochemical cell

[0188] After depositing 3 pm of porous U3PO4 on each of the previously developed electrodes (see examples 1 & 2), the two subsystems were stacked so that the U3PO4 films were in contact. This stack was then hot-pressed under vacuum.

[0189] To do this, the stack was placed under a pressure of 1.5 MPa and then dried under vacuum for 30 minutes at 10' 3 bars. The press plates were then heated to 450°C at a rate of 4°C / second. At 450°C, the stack was then thermo-compressed under a pressure of 45 MPa for 1 minute, and then the system was cooled to room temperature.

[0190] Once the assembly was completed, a rigid, multi-layer system consisting of one or more assembled battery cells was obtained.

[0191] This assembly was then impregnated in an electrolytic solution comprising 0.7 M LiTFSI in PYR14TFSI. The electrolyte instantly enters the porosities by capillarity. The system was kept immersed for 1 minute, then the surface of the cell stack was dried by a N2 blade.

Claims

CLAIMS 1. 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%, and pores with an average diameter of less than 100 nm, said manufacturing method being characterized in that: (a) a substrate, at least one precursor of an electronically conductive oxide material, and a colloidal suspension or a paste comprising aggregates or agglomerates of primary nanoparticles, of at least one active electrode material P, with an average primary diameter Dso of between 2 nm and 400 nm, preferably between 2 nm and 100 nm, and more preferably between 2 nm and 60 nm, are provided, said aggregates or agglomerates having an average diameter Dso of between 50 nm and 900 nm, and preferably between 100 nm and 800 nm, knowing that said substrate may 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 comprising aggregates or agglomerates of primary nanoparticles, 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 formed by: electrophoresis, an additive manufacturing process, extrusion, 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, (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 drying step (d), (e) the transformation of the precursor(s) of an electronically conductive oxide material into an electronically conductive oxide material is carried out, so that said dried layer comprises said electronically conductive oxide material, (f) said layer is consolidated, by thermal and / or mechanical treatment, preferably by sintering, to obtain a porous, preferably mesoporous, electrode, it being understood that steps (e) and (f) may be carried out during the same heat treatment.

2. Method for manufacturing a porous electrode according to claim 1, characterized in that step (b) is carried out by bringing into contact the colloidal suspension or the paste supplied in step (a) comprising aggregates or agglomerates of primary nanoparticles, of at least one active electrode material P 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. Method for manufacturing a porous electrode according to claim 1 or 2, 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 methylene carbonate) (PTMC).

4. Method for manufacturing a porous electrode according to any one of claims 1 to 3, 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 being, preferably, 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.

5. Method for manufacturing a porous electrode according to any one of claims 1 to 4, characterized in that said electronically conductive oxide material is chosen from: - tin oxide (SnC>2), 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 (ln2O3), gallium oxide (Ga2O3), molybdenum oxide (MoO3), molybdenum and strontium oxide (SrMoCh), a mixture of two of these oxides such as indium-tin oxide corresponding to a mixture of indium oxide (ln2O3) and tin oxide (SnC>2), 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 aluminum (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).

6. Method for manufacturing a porous electrode according to any one of claims 1 to 5, characterized in that said porous electrode obtained at the end of step (f) has a specific surface area of between 10 m 2 / g and 500 m 2 / g and / or a thickness between 2 pm and 400 pm, preferably between 2 pm and 300 pm, more preferably between 3 pm and 200 pm.

7. Method for manufacturing a porous electrode according to any one of claims 1 to 5, characterized in that said porous electrode obtained at the end of step (f) has a specific surface area of between 10 m 2 / g and 500 m 2 / g; and / or a thickness of between 2 pm and 20 pm when the substrate is a substrate capable of acting as an electric current collector, and / or a thickness of between 25 pm and 500 pm, preferably between 50 pm and 400 pm, when the substrate is an intermediate substrate.

8. Method for manufacturing a porous electrode according to any one of claims 1 to 5, 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.

9. A method of manufacturing a porous electrode according to any one of claims 1 to 8, characterized in that said colloidal suspension or paste supplied in step (a) comprises organic additives, such as ligands, stabilizers, binders or residual organic solvents, and a heat treatment is carried out, preferably in an oxidizing atmosphere, of said dried layer obtained at the end of step d) according to any one of claims 1 to 7, or of said porous plate according to claim 8, it being understood that this heat treatment and steps (e) and / or (f) can be carried out during the same heat treatment.

10. A method of manufacturing a porous electrode according to any one of claims 1 to 9, wherein said active electrode material P is selected from group (A) formed by: - the oxides LiMn2O4, Ui +x Mn2-xO4 with0 < x < 0.15, LiCoO2, LiNiC>2, LiMn1.5Nio.5O4, LiMni,sNio,5-xX x 040where 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, LiMn2-xM x O4 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 / 3O2 , LiNi0.8Co0.15AI0.05O2, LiAl x Mn2-xO4 with0 < x < 0.15, LiNii / x Coi / y Mni / z O2 with x+y+z =10; - Li x M yO2 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 ; Li1.20Nbo.20Mno.60O2 ; - Lii+xNbyMe z ApO2 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<1 ; 0<y<0.5; 0.25<z<1 ; avec A Me et A Nb, et 0<p<0.2 ; - LixNby. a N a M z .bPbO2-cFc where 1.2 <x<1.75; 0<y<0.55; 0.1<z<1 ; 0<a<0.5; 0<b<1 ; 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 ; - Li1.25Nbo.25Mno.50O2; Li1.3Nbo.3Mno.40O2; Li1.3Nbo.3Feo.40O2; Li1.3Nbo.43Nio.27O2; Li1.3Nb0.43Co0.27O2; Li1.4Nbo.2Mno.53O2; - LixNi0.2Mn0.eOy where 0.00 <x<1.52; 1.07<y<2.4 ; Li1.2Nio.2Mno.6O2 ; - LiNi x Coy Mni-x-yO2 where 0 < x and y < 0.5; LiNi x This z Co y Mni-x-yO2 where 0 < x and y < 0.5 and 0 < z; - phosphates LiFePO4, LiMnPÛ4, UCOPO4, LiNiPÛ4, Li3V2(PO4)3, U2MPO4F with M = Fe, Co, Ni or a mixture of these different elements, UMPO4F with M = V, Fe, T or a mixture of these different elements; phosphates of formula LiMM'PCU, with M and M' (M M') selected from Fe, Mn, Ni, Co, V such as LiFe x Coi. x PO4and where 0 < x < 1; - Feo.gCoo OF ; FeFs; UMSO4F with M = Fe, Co, Ni, Mn, Zn, Mg; - titanium oxysulfides (TiO y S z with z=2-y and 0.3 <y<1), les oxysulfures de tungstène (WOySz avec 0.6<y<3 et 0.1 <z<2), CuS, CUS2, Li x V2Os with 0 < x < 2, LLVsOs with 0 < x < 1,7, Li x TiS2with 0 < x < 1, titanium and lithium oxysulfides Li x TiO y S z with z=2-y, 0.3 <y<1 et 0 < x < 1 , Lix WO y S z with z=2-y, 0.3 <y<1 et 0 < x < 1 , Li x CuS with 0 < x < 1 , Li x CuS2with 0 < x < 1; or in group (B) formed by: transition metal oxides: o Na x MO 2+z with M chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z < 0.3 and 0 <x < 1 , de préférence 0 < x < 0.44 or 0.44 < x < 0.67 or 0.67 < x < 1 ; o Na x M u / 2M'v / 2O 2+z with u + v = 2 and M, M' chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z< 0.3 and 0 <x < 1 , de préférence 0 < x < 0.44 ou 0.44 < x < 0.67 ou 0.67 < x < 1 ; o Na x M u / 3M'v / 3M”w / 3O 2+z with u + v + w = 3 and M, M', M” chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z< 0.3 and O <x < 1 , de préférence 0 < x < 0.44 ou 0.44 < x < 0.67 ou 0.67 < x < 1 ; o Na x Mn y Neither zFeo.iMgo.i02with 0.67 < x < 1.0; 0.5 < y < 0.7 and 0.1 < z < 0.3; Prussian blue and / or Prussian blue analogues known by the acronym PBA from the English “Prussian blue analogues”: o Na x M 1 [M 2 '(CN)e] y .nH2O, M 1 being a transition metal or an alloy of transition metals, M 2 ' being a transition metal, the transition metal and the transition metal alloy being chosen from Fe, Ni, Co and Mn, with 0 < x < 2; y < 1 and 0 < n < 12; the polyanionic compounds: o Na x M2(XO4)3 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W, such as Na3V2(PO4)3; o Na x M3(XO4)2(X2O?) with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o Na x M(X2O?) with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o Na xM2(XC>4)2F3 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o Na x M2(XO4)2F3-yO y with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and O.07 < y < 0.12 and X = P, S, As, Si, Mo or W; oNa x M2C>2(XO4)2F with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o Na x MXO4 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; or in group (C) formed by: transition metal oxides: o K X MO 2+Z with M chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z < 0.3 and 0 <x < 1 , de préférence 0 < x < 0.44 or 0.44 < x < 0.67 or 0.67 < x < 1 ; o K X M U / 2M'V / 2O2+Z with u + v = 2 and M, M' chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z< 0.3 and 0 <x < 1 , de préférence 0 < x < 0.44 ou O.44 < x < 0.67 or 0.67 < x < 1; oK X M U / 3M'V / 3M”W / 3O2+Z with u + v + w = 3 and M, M', M” chosen from Mg, Ca, Li, Mn, Ni, Co, Cr, Sc, Te with z< 0.3 and O <x < 1 , de préférence 0 < x < 0.44 ou 0.44 < x < 0.67 ou 0.67 < x < 1 ; o K x Mn y Neither z Feo.iMgo.i02 with 0.67 < x < 1.0; 0.5 < y < 0.7 and 0.1 < z < 0.3; Prussian blue and / or Prussian blue analogues known by the acronym PBA from the English “Prussian blue analogues”: o K x M 1 [M 2 '(CN)e]y.nH2O, M 1 being a transition metal or an alloy of transition metals, M 2 ' being a transition metal, the transition metal and the transition metal alloy being chosen from Fe, Ni, Co and Mn, , with 0 < x < 2; y < 1 and 0 < n < 12; the polyanionic compounds: o K X M2(XO4)3 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W, such that NasX^PCLh; oK XM3(XO4)2(X2O?) with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o K X M(X2O?) with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o K x M2(XO4)2F3 with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o K x M2(XO4)2F3-yO y with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and 0.07 < y < 0.12 and X = P, S, As, Si, Mo or W; o K X M2O2(XC>4)2F with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W; o K x MXO4with 0 < x < 4, M = V, Fe, Cr, Mn, Co, Ni or Sc and X = P, S, As, Si, Mo or W.

11. A method of manufacturing a porous electrode according to any one of claims 1 to 9, wherein said electrode active material P is selected from group (D) formed by: • Li4TisOi2, Li4Tis-xM x Oi2 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: Nb2O 5±5 , Nbi2WO33±s, Nbi4W3O44±s, NbisWi6O93±8 , NbieWsOss a with 0 s S < 2, LiNbO3, TiNb2C>7±8, LiwTiNb2C>7 with w>0, Tii-xM 1 x Nb2-yM 2 yO7±8 or Li w Tii-xM 1 x Nb2- yM 2 yC>7±8 in which M 1 and M 2 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, M 1 and M 2 which may be identical or different from each other, and in which 0 < w < 5 and 0 < x < 1 and 0 < y < 2 and 0 < ô < 0.3; The x Tii-2xNb2+xO7 where 0 <x<0.5 ; M xTii-2xNb2+xO7±5in 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< 5 sO.3 ; Ga0.10Ti0.80Nb2.10O7 ; Fe0.10Ti0.80Nb2.10O7 ; M x Ti2-2xNbio + x029±5in 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< 5 <0.3 ; Tii-xM 1 x Nb2-yM 2 yO7-zM 3 z or Li w Tii-xM 1 xNb2-yM 2 yO7-zM 3 z in which - M 1 and M 2 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, - M 1 and M 2which may be identical or different from each other, - M 3 is at least one halogen, - and in which 0 < w < 5 and 0 < x < 1 and 0 < y < 2 and z < 0.3; TiNb2C>7-zM 3 z or Li w TiNb2O7- z M 3 z in which M 3 is at least one halogen, preferably selected from F, Cl, Br, I or a mixture thereof, and 0 < z < 0.3 and 0 < w < 5; Tii-xGe x Nb2-yM 1 yO7±z , Li w Tii- x Ge x Nb2-yM 1 yO7±z , Tii- x This x Nb2-yM 1 yO7±z , UwTii- x This x Nb2-yM 1 y O7±z in which - M 1 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 < 5 and 0 < x < 1 and 0 < y < 2 and z < 0.3; Tii- x Ge x Nb2-yM 1 yO7-zM 2 z , Li w Tii- x Ge x Nb2-yM 1 yO7-zM 2 z, Tii- x This x Nb2-yM 1 yO7- z M 2 z , LiwTii- x This x Nb2-yM 1 yO7-zM 2 z , in which - M 1 and M 2 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, - M 1 and M 2 which may be identical or different from each other, - and in which 0 < w < 5 and 0 < x < 1 and 0 < y < 2 and z < 0.3; • TiO2 ; TiO x Ny 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; • MO type nitrides and oxynitrides x N y where M is at least one element selected 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-xM x N 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-xM x N with M being cobalt (Co) and 0 < x < 0.5; Li3-xM x N with M being nickel (Ni) and 0 < x < 0.6; Li3-xM x N with M being copper (Cu) and 0 < x < 0.3; • lithium iron phosphate, with the typical formula LiFePO4; • mixed oxynitrides of silicon and tin, with the typical formula Si a SnbO y N z 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; • Si type nitrides x N y , in particular with x=3 and y=4; Sn x N y , in particular with x=3 and y=4, Zn x N y , in particular with x=3 and y=2; Li3- X M X N with 0 <x<0,5 pour M=Co, 0<x<0,6 pour M=Ni, 0<x<0,3 pour M=Cu; Si3- X M X N4 with M=Co or Fe and 0 <x<3. • the oxides SnC>2, SnO, Li2SnO3, SnSiCh, Li x SiO y with x>=0 and 2>y>0, Li4Ti50i2, TiNb2O7, CO3O4, SnBo,ePo,402,9 and TiO2, • Si, Sn, SiC>2, SnC>2, 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. or in group (E) formed by: alloys based on Si, Ge, Sn, Sb, Bi or P and alloys of these different compounds MXenes. MXenes constitute a class of 2D materials of type M stoichiometry n +iXn T x with M a transition metal, preferably chosen from Sc, Ti, V, Cr, Y, Zr, Nb, Mo, Hf, Ta, W and X is chosen from C and / or N and T a surface termination chosen from F, Cl, I, Br, O, S, Se, Te, OH, NH2, 1 < n < 4 conversion anode materials such as o oxides of type G2TisO7, G4TisOi2, GTi2(PÛ4)3, G being Na or K o oxides, sulfides, selenides, phosphide of the following elements or their alloys: Si, Ge, Sn, Sb, Bi.

12. Porous electrode obtainable by the method according to any one of claims 1 to 11.

13. 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 11, or implementing a porous electrode according to claim 12.

14. Method according to claim 13, 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, cells photovoltaic cells, photoelectrochemical cells and batteries such as lithium ion batteries, sodium ion batteries, potassium ion batteries.

15. The method of claim 14, wherein said device is a lithium ion battery and the method for manufacturing a porous electrode according to claim 10 is carried out to manufacture a cathode with the active electrode material P selected from group (A) or the method of claim 11 is carried out to manufacture an anode with the active electrode material P selected from group (D).

16. The method of claim 14, wherein said device is a sodium ion battery and the method for manufacturing a porous electrode according to claim 10 is carried out to manufacture a cathode with the active electrode material P selected from group (B) or the method of claim 11 is carried out to manufacture an anode with the active electrode material P selected from group (E).

17. The method of claim 14, wherein said device is a potassium ion battery and the method for manufacturing a porous electrode according to claim 10 is carried out to manufacture a cathode with the active electrode material P selected from group (C) or the method of claim 11 is carried out to manufacture an anode with the active electrode material P selected from group (E).

18. Method according to any one of claims 13 to 17, wherein said device is a lithium, sodium or potassium ion battery and said porous electrode is impregnated with an electrolyte, preferably with a phase carrying lithium ions, sodium ions, 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, either in the porous structure, 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), polydimethylsiloxane (PDMS), poly(E-caprolactone) (PCL) and poly(tri methylene carbonate) (PTMC).

19. Device for storing or producing electrical energy capable of being obtained by the method according to any one of claims 13 to 18.

20. Device for storing or producing electrical energy according to claim 19, characterized in that it 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.

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