METHOD FOR MANUFACTURING A POROUS ELECTRODE, AND MICROBATTERY CONTAINING SUCH AN ELECTRODE

Abstract

A method for manufacturing an electrode having a porosity of between 20% and 60% by volume and pores with an average diameter of less than 50 nm. In the method, provision is made of a substrate and a colloidal suspension of aggregates or agglomerates of monodisperse primary nanoparticles of an active electrode material, having an average primary diameter D.sub.50 of between 2 and 100 nm, the aggregates or agglomerates having an average diameter D.sub.50 of between 50 nm and 300 nm. A layer is deposited from said colloidal suspension on the substrate. The deposited layer is then dried and consolidated to obtain a mesoporous layer. A coating of an electronically conductive material is then deposited on and inside the pores of the porous layer. Such a porous electrode can be used in lithium-ion microbatteries.

Claims

1-17. (canceled)

18. A method for manufacturing a porous electrode for an electrochemical device, the method comprising: (a) providing a substrate and a colloidal suspension or a paste that includes aggregates or agglomerates of monodisperse primary nanoparticles, of at least one active electrode material, having an average primary diameter of between 2 nm and 60 nm, the aggregates or agglomerates having an average diameter of between 100 nm to 200 nm; (b) depositing a layer from the colloidal suspension or paste on at least one face of the substrate via at least one of electrophoresis, a printing method and preferably ink-jet printing or flexographic printing; (c) drying the deposited layer, heat treating the dried layer under an oxidizing atmosphere, and then consolidating the heat treated by pressing and/or heating to obtain a mesoporous layer; and (d) depositing, on and inside the pores of the mesoporous layer, a coating of an electronically conductive material.

19. The method of claim 18, wherein the substrate is configured to act as an electric current collector.

20. The method of claim 18, wherein the substrate comprises an intermediate substrate.

21. The method of claim 20, further comprising forming a porous plate by separating the mesoporous layer from the intermediate substrate.

22. The method of claim 21, wherein the deposited layer is dried before separating the mesoporous layer from the intermediate substrate.

23. The method of claim 21, wherein the deposited layer is dried after separating the mesoporous layer from the intermediate substrate.

24. The method of claim 18, wherein the mesoporous layer: is free of binder, has a porosity of between 25% and 50% by volume, and has pores having an average diameter of less than 50 nm.

25. The method of claim 18, wherein the mesoporous layer has a thickness of between 4 .Math.m and 400 .Math.m.

26. The method of claim 18, wherein the colloidal suspension or paste comprises organic additives that include ligands, stabilisers, binders, or residual organic solvents.

27. The method of claim 18, wherein the electronically conductive material comprises carbon.

28. The method of claim 18, wherein depositing the electronically conductive material is conducted by: atomic layer deposition ALD technique, or immersion of the mesoporous layer in a liquid phase including a precursor of the electronically conductive material, and then transforming the precursor into the electronically conductive material.

29. The method of claim 28, wherein: the precursor comprises a carbon-rich compound that includes a polysaccharide, and transforming the precursor into the electronically conductive material is conducted by pyrolysis under an inert atmosphere.

30. The method of claim 25, wherein the at least one active electrode material is selected from the group consisting of: oxides LiMn.sub.2O.sub.4, Li.sub.1+xMn.sub.2-xO.sub.4, where 0 < x < 0.15, LiCoO.sub.2, LiNiO.sub.2, LiMn.sub.1.5Ni.sub.0.5O.sub.4, LiMn.sub.1.5Ni.sub.0.5-xX.sub.xO.sub.4, where X is selected from Al, Fe, Cr, Co, Rh, Nd, Sc, Y, Lu, La, Ce, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and where 0 < x < 0.1, LiMn.sub.2-xM.sub.xO.sub.4 where M = Er, Dy, Gd, Tb, Yb, Al, Y, Ni, Co, Ti, Sn, As, Mg or a mixture thereof where 0 < x < 0.4, LiFeO.sub.2, LiMn.sub.⅓Ni.sub.⅓Co.sub.⅓O.sub.2, LiNi.sub.0.8Co.sub.0.15Al.sub.0.05O.sub.2, LiAl.sub.xMn.sub.2-xO.sub.4 where 0 ≤ x < 0.15, LiNi.sub.⅟xCo.sub.⅟yMn.sub.⅟zO.sub.2 where x+y+z =10; Li.sub.xM.sub.yO.sub.2 where 0.6≤y≤0.85; 0≤x+y≤2, where M is selected from Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Sn, and Sb or a mixture thereof, Li.sub.1.20Nb.sub.0.20Mn.sub.0.60O.sub.2; Li.sub.1+xNb.sub.yMe.sub.zA.sub.pO.sub.2, where Me is at least one transition metal selected from: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Rf, Db, Sg, Bh, Hs and Mt, where 0.6<x<1; 0<y<0.5, 0.25≤z<1, A ≠ Me, A ≠ Nb, and 0≤p≤0.2; Li.sub.xNb.sub.y-aN.sub.aM.sub.z-bP.sub.bO.sub.2-cF.sub.c 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, and M, N, and P are each at least one of the elements selected from the group consisting of Ti, Ta, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Zr, Y, Mo, Ru, Rh, and Sb; Li.sub.1.25Nb.sub.0.25Mn.sub.0.50O.sub.2, Li.sub.1.3Nb.sub.0.3Mn.sub.0.40O.sub.2, Li.sub.1.3Nb.sub.0.3Fe.sub.0.40O.sub.2, Li.sub.1.3Nb.sub.0.43Ni.sub.0.27O.sub.2, Li.sub.1..sub.3Nbo..sub.43Coo..sub.27O.sub.2, and Li.sub.1.4Nb.sub.0.2Mn.sub.0.53O.sub.2; Li.sub.xNi.sub.0.2Mn.sub.0.6O.sub.y where 0.00≤x≤1.52, 1.07≤y<2.4, Li.sub.1.2Ni.sub.0.2Mn.sub.0.6O.sub.2; LiNi.sub.xCo.sub.yMn.sub.1-.sub.x-.sub.yO.sub.2 where 0 ≤ x and y ≤ 0.5, LiNi.sub.xCe.sub.zCo.sub.yMn.sub.1-.sub.x-.sub.yO.sub.2 where 0 ≤ x and y ≤ 0.5, and 0 ≤ z; phosphates LiFePO.sub.4, LiMnPO.sub.4, LiCoPO.sub.4, LiNiPO.sub.4, Li.sub.3V.sub.2(PO.sub.4).sub.3, Li.sub.2MPO.sub.4F where M = Fe, Co, Ni or a mixture thereof, LiMPO.sub.4F where M = V, Fe, T or a mixture thereof, phosphates of formula LiMM′PO.sub.4, where M and M′ (M ≠ M′) selected from Fe, Mn, Ni, Co, V, LiFe.sub.xCo.sub.1-xPO.sub.4 where 0 < x < 1; Fe.sub.0.9Co.sub.0.1OF; LiMSO.sub.4F where M = Fe, Co, Ni, Mn, Zn, Mg; and all lithiated forms of chalcogenides that include: V.sub.2O.sub.5, V.sub.3O.sub.8, TiS.sub.2, titanium oxysulfides (TiO.sub.yS.sub.z where z=2-y and 0.3≤y≤1), tungsten oxysulfides (WO.sub.yS.sub.z where 0.6<y<3 and 0.1<z<2), CuS, CuS.sub.2, Li.sub.xV.sub.2O.sub.5 where 0 <x≤2, Li.sub.xV.sub.3O.sub.8 where 0 < x ≤ 1.7, Li.sub.xTiS.sub.2 where 0 < x ≤ 1, titanium and lithium oxysulfides where Li.sub.xTiO.sub.yS.sub.z where z=2-y, 0.3≤y≤1 and 0 < x ≤ 1, Li.sub.xWO.sub.yS.sub.z where z=2-y, 0.3≤y≤1 and 0 < x ≤ 1, Li.sub.xCuS where 0 < x ≤ 1, Li.sub.xCuS.sub.2 where 0 < x ≤ 1.

31. The method of claim 25, wherein the at least one active electrode material is selected from the group consisting of: Li.sub.4Ti.sub.5O.sub.12, Li.sub.4Ti.sub.5-xM.sub.xO.sub.12 where M = V, Zr, Hf, Nb, Ta and 0 ≤ x ≤ 0.25; niobium oxides and mixed niobium oxides where titanium, germanium, cerium or tungsten, and from the group consisting of: Nb.sub.2O.sub.5±δ, N.sub.b18W.sub.16O.sub.93±δ, Nb.sub.16W.sub.5O.sub.55±δ where 0 ≤ x < 1 and 0 ≤ δ ≤ 2, LiNbO.sub.3, TiNb.sub.2O.sub.7±δ, Li.sub.wTiNb.sub.2O.sub.7 where w≥0, Ti.sub.1-xM.sup.1.sub.xNb.sub.2-yM.sup.2.sub.yO.sub.7±δ or Li.sub.wTi.sub.1-.sub.xM.sup.1.sub.xNb.sub.2-yM.sup.2.sub.yO.sub.7±δ where M.sup.1 and M.sup.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.sup.1 and M.sup.2, and where 0 ≤ w ≤ 5 and 0 ≤ x ≤ 1 and 0 ≤ y ≤ 2 and 0 ≤ δ ≤ 0.3; La .sub.xTi.sub.1-.sub.2xNb.sub.2+xO.sub.7 where 0<x<0.5; M.sub.xTi.sub.1-.sub.2xNb.sub.2+xO.sub.7±δ, where M is at least one element selected from the group consisting of Fe, Ga, Mo, Al, B, and where 0<x≤0.20 and -0.3≤ δ ≤0.3; Ga.sub.0.10Ti.sub.0.80Nb.sub.2.10O.sub.7; Fe.sub.0.10Ti.sub.0.80Nb.sub.2.10O.sub.7; M.sub.xTi.sub.2-.sub.2xNb.sub.10+xO.sub.29±δ, where M is at least one element selected from the group consisting of Fe, Ga, Mo, Al, B, and where 0<x≤0.40 and -0.3≤ δ ≤0.3; Ti.sub.1-xM.sup.1.sub.xNb.sub.2-yM.sup.2.sub.yO.sub.7-zM.sup.3.sub.z or Li.sub.wTi.sub.1-xM.sup.1.sub.xNb.sub.2-yM.sup.2.sub.yO.sub.7-zM.sup.3.sub.z, where M.sup.1 and M.sup.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.sup.3 is at least one halogen, and 0 ≤ w ≤ 5, 0 ≤x ≤ 1, 0 ≤y≤2, and z ≤0.3; TiNb.sub.2O.sub.7-zM.sup.3.sub.z or Li.sub.wTiNb.sub.2O.sub.7-zM.sup.3.sub.z, where M.sup.3 is at least one halogen that includes F, Cl, Br, I or a mixture thereof, and 0 < z ≤ 0.3; Ti.sub.1-xGe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7±z, Li.sub.wTi.sub.1-xGe.sub.xNb.sub.2-yM.sup.1yO.sub.7±z, Ti.sub.1-xCe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7±z, Li.sub.wTi.sub.1-xCe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7±z, where M.sup.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, 0 ≤ x ≤ 1, 0 ≤y ≤2, and z ≤ 0.3; Ti.sub.1-xGe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7-zM.sup.2.sub.z, Li.sub.wTi.sub.1-xGe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7-zM.sup.2.sub.z, Ti.sub.1-xCe.sub.xNb.sub.2-.sub.yM.sup.1.sub.yO.sub.7-z M.sup.2.sub.z, Li.sub.wTi.sub.1-xCe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7-zM.sup.2.sub.z, where M.sup.1 and M.sup.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, 0 ≤ w ≤ 5, 0 ≤ x ≤ 1, 0 ≤ y ≤ 2, and z ≤ 0.3; TiO2; and LiSiTON.

32. A porous electrode formed using the method of claim 18.

33. A porous electrode of claim 32, wherein the porous electrode: has a porosity of between 20% and 60% by volume, is free of binder, and has pores with an average diameter of less than 50 nm.

34. A method for manufacturing a battery designed to have a capacity no greater than 1 mAh, the method comprising: forming a porous electrode formed using the method of claim 18.

35. The method of claim 34, wherein the battery comprises a lithium-ion battery.

36. The method of claim 34, wherein the porous electrode comprises an anode or a cathode.

37. The method of claim 34, further comprising impregnating the porous electrode with an electrolyte that includes phase carrying lithium ions selected from the group consisting of: an electrolyte composed of at least one aprotic solvent and at least one lithium salt; an electrolyte composed of at least one ionic liquid and at least one lithium salt; a mixture of at least one aprotic solvent and at least one ionic liquid and at least one lithium salt; a polymer made ionically conductive by adding at least one lithium salt; and a polymer made ionically conductive by adding a liquid electrolyte, either in the polymer phase or in a mesoporous structure.

Description

DRAWINGS

[0116] FIGS. 1 to 6 illustrate various aspects and embodiments of the invention, without limiting its scope.

[0117] FIG. 1 shows a diffractogram of primary nanoparticles used in the suspension before the formation of agglomerates.

[0118] FIG. 2 shows a picture obtained by transmission electron microscopy of primary nanoparticles of the same sample as that of FIG. 1.

[0119] FIG. 3 schematically illustrates nanoparticles before heat treatment.

[0120] FIG. 4 schematically illustrates nanoparticles after heat treatment, illustrating the phenomenon of “necking.”

[0121] FIG. 5 shows the evolution of the relative capacity of a battery according to the invention depending on the number of charge and discharge cycles.

[0122] FIG. 6 shows a charging curve of the same battery: the curve A corresponds to the state of charge (right scale), the curve B corresponds to the current absorbed (left scale).

DESCRIPTION

1. Definitions

[0123] As part of this document, the size of a particle is defined by its largest dimension. “Nanoparticle” means any particle or object of nanometric size having at least one of its dimensions less than or equal to 100 nm.

[0124] “Ionic liquid” means any liquid salt, capable of transporting electricity, being different from all the melted salts by a melting temperature below 100° C. Some of these salts remain liquid at room temperature and do not solidify, even at very low temperature. Such salts are called “ionic liquids at room temperature.”

[0125] “Mesoporous” materials mean any solid that has within its structure pores called “mesopores” having an intermediate size between that of the micropores (width less than 2 nm) and that of the macropores (width greater than 50 nm), namely a size comprised between 2 nm and 50 nm. This terminology corresponds to that adopted by IUPAC (International Union for Pure and Applied Chemistry), which serves as a reference for the person skilled in the art. The term “nanopore” is therefore not used here, even if the mesopores as defined above have nanoscale dimensions within the meaning of the definition of the nanoparticles, knowing that the pores with a size smaller than that of the mesopores are called by the person skilled in the art “micropores.”

[0126] A presentation of the concepts of porosity (and the terminology that has just been exposed above) is given in the article “Texture des matériaux pulverulents ou poreux” by F. Rouquercol and al., published in the collection “Techniques de I′Ingénieur”, treaty of Analysis and Characterisation, fascicle P 1050; this article also describes the techniques for characterising porosity, in particular the BET method.

[0127] Within the meaning of the present invention, “mesoporous electrode” or “mesoporous layer” means an electrode, respectively a layer which has mesopores. As will be explained below, in these electrodes or layers the mesopores contribute significantly to the total porous volume; this fact is translated by the term “mesoporous electrode or layer of mesoporous porosity greater than X% by volume” used in the description below.

[0128] The term “aggregate” means, according to the definitions of IUPAC a weakly bound assembly of primary particles. In this case, these primary particles are nanoparticles having a diameter that can be determined by transmission electron microscopy. An aggregate of aggregated primary nanoparticles can normally be destroyed (that is to say reduced to primary nanoparticles) to make the primary nanoparticles suspended in a liquid phase under the effect of ultrasound, according to a technique known to the person skilled in the art.

[0129] The term “agglomerate” means, according to the definitions of IUPAC, a strongly bound assembly of primary particles or aggregates.

[0130] The term “microbattery” is used here for a battery of a capacity not exceeding 1 mAh. Typically, microbatteries are designed to be compatible with microelectronics manufacturing methods.

2. Preparation of Suspensions of Nanoparticles

[0131] The method for preparing porous electrodes according to the invention starts from a suspension of nanoparticles. It is preferable not to prepare these suspensions of nanoparticles from dry nanopowders. They can be prepared by grinding powders or nanopowders in the liquid phase, and/or using ultrasonic treatment to deagglomerate nanoparticles.

[0132] In another embodiment of the invention the nanoparticles are prepared in suspension directly by precipitation. The synthesis of nanoparticles by precipitation allows to obtain primary nanoparticles of very homogeneous size with a unimodal size distribution that is to say a very tight and monodisperse distribution, of good crystallinity and purity. The use of these very homogeneous nanoparticles and narrow distribution allows to obtain a porous structure of controlled and open porosity after deposition. The porous structure obtained after deposition of these nanoparticles has little, preferably no closed pores.

[0133] In an even more preferred embodiment of the invention the nanoparticles are prepared directly at their primary size by hydrothermal or solvothermal synthesis; this technique allows to obtain nanoparticles with a very narrow size distribution called “monodisperse nanoparticles”. The size of these non-aggregated or non-agglomerated nanopowders/nanoparticles is called primary size. It is typically comprised between 2 nm and 150 nm. It is advantageously comprised between 10 nm and 50 nm, preferably between 10 nm and 30 nm; this promotes in subsequent method steps the formation of an interconnected mesoporous network with electronic and ionic conduction, thanks to the phenomenon of “necking.”

[0134] In an advantageous embodiment, the suspension of monodisperse nanoparticles can be carried out in the presence of ligands or organic stabilisers so as to avoid aggregation, or even the agglomeration of nanoparticles. Binders may also be added in the suspension of nanoparticles to facilitate the production of depositions or raw tapes, in particular thick depositions without cracks.

[0135] Indeed, in the context of the present invention, it proves to be preferable to start from a suspension of non-agglomerated primary particles, within which the agglomeration is then induced or caused, rather than allowing the agglomeration of the primary particles to occur spontaneously at the stage of preparation of the suspension.

[0136] This suspension of monodisperse nanoparticles can be purified to remove any potentially interfering ions. Depending on the degree of purification it can then be specially treated to form aggregates or agglomerates of a controlled size. More specifically, the formation of aggregates or agglomerates can result from the destabilisation of the suspension caused in particular by ions, by the increase in the dry extract of the suspension, by changing the solvent of the suspension, by the addition of a destabilising agent. If the suspension has been completely purified it is stable, and ions are added to destabilise it, typically in the form of a salt; these ions are preferably lithium ions (preferably added in the form of LiOH).

[0137] If the suspension has not been completely purified the formation of aggregates or agglomerates can be done alone in a spontaneous way or by ageing. This way of proceeding is simpler because it involves fewer purification steps, but it is more difficult to control the size of aggregates or agglomerates. One of the essential aspects for the manufacture of electrodes according to the invention consists in properly controlling the size of the primary particles of electrode materials and their degree of aggregation or agglomeration.

[0138] If the stabilisation of the suspension of nanoparticles occurs after the formation of agglomerates, they will remain in the form of agglomerates; the suspension obtained can be used to make mesoporous depositions.

[0139] It is this suspension of aggregates or agglomerates of nanoparticles which is then used to deposit by electrophoresis, by the ink-jet printing method, by flexographic printing, by doctor blade coating, by roll coating, by curtain coating, by extrusion slot-die coating, or by dip-coating the porous, preferably mesoporous, electrode layers, according to the invention.

[0140] According to the observations of the applicant, with an average diameter of the aggregates or agglomerates of nanoparticles comprised between 80 nm and 300 nm (preferably between 100 nm to 200 nm), a mesoporous layer having an average diameter of mesopores comprised between 2 nm and 50 nm is obtained during the subsequent steps of the method.

[0141] According to the invention, the porous electrode layer can be deposited by the ink-jet printing method or by a coating method, and in particular by the dip-coating method, by roll coating, by curtain coating, by slot-die coating, or else by doctor blade coating, from a fairly concentrated suspension comprising nanoparticle aggregates or agglomerates of the active material P.

[0142] It is also possible to deposit the porous electrode layer by electrophoresis, but then advantageously use is made of a less concentrated suspension containing nanoparticle agglomerates of the active material P.

[0143] The methods for depositing aggregates or agglomerates of nanoparticles by electrophoresis, by the dip-coating method, by ink-jet, by roll coating, by curtain coating, by slot-die coating or by doctor blade coating are methods which are simple, safe that easy to implement and to industrialise and which allow to obtain a final homogeneous porous layer. Electrophoretic deposition enables uniform deposition of layers over large areas with high deposition rates. The coating techniques, in particular those mentioned above, allow to simplify the management of the baths compared to the electrophoretic deposition techniques because the suspension does not become depleted of particles during the deposition. Ink-jet printing deposition allows for localised depositions.

[0144] Porous layers made of a thick layer can be made in one step by roll coating, curtain coating, slot die coating, or by doctor blade coating (that is to say using a doctor blade).

[0145] It is noted that colloidal suspensions in water and/or ethanol and/or IPA and mixtures thereof are more fluid than those obtained in the NMP. It is thus possible to increase the dry extract of the suspension of nanoparticle agglomerates. These agglomerates preferably have sizes of less than or equal to 200 nm and have polydisperse sizes, even with two populations with different sizes.

[0146] Compared to the prior art, the formulation of inks and pastes for the production of the electrodes is simplified. There is no more risk of carbon black agglomerates in the suspension when increasing dry extract.

3. Deposition of Layers and Their Consolidation

[0147] In general, a layer of a suspension of nanoparticles is deposited on a substrate, by any appropriate technique, and in particular by a method selected from the group formed of: electrophoresis, a printing method and preferably ink-jet printing or flexographic printing, a coating method and preferably doctor blade coating, roll coating, curtain coating, dip-coating, or slot-die coating. The suspension is typically in the form of an ink, that is to say a fairly fluid liquid, but can also have a pasty consistency. The deposition technique and the implementation of the deposition method must be compatible with the viscosity of the suspension, and vice versa.

[0148] The deposited layer will then be dried. The layer is then consolidated to obtain the desired mesoporous ceramic structure. This consolidation will be described below. It can be performed by heat treatment, by a heat treatment preceded by a mechanical treatment, and optionally by a thermomechanical treatment, typically a thermocompression. During this thermomechanical or heat treatment, the electrode layer will be freed of any organic constituent and organic residue (such as the liquid phase of the suspension of the nanoparticles and any surfactant products): it becomes an inorganic layer (ceramic). The consolidation of a plate is preferably carried out after its separation from its intermediate substrate, since the latter would risk being degraded during this treatment.

[0149] The deposition of the layers, their drying and their consolidation are likely to raise some problems which will be discussed now. These problems are partly linked to the fact that during the consolidation of the layers a shrinkage occurs which generates internal stresses.

3.1. Substrate Capable of Acting as a Current Collector

[0150] According to a first embodiment, the layers of electrodes are each deposited on a substrate capable of acting as an electric current collector. Layers including the suspension of nanoparticles or agglomerates of nanoparticles can be deposited on one face or on both faces, by the deposition techniques indicated above. The substrate serving as a current collector within batteries using porous electrodes according to the invention can be metallic, for example a metal strip (that is to say a laminated metal sheet). The substrate is preferably selected from strips of tungsten, molybdenum, chromium, titanium, tantalum, stainless steel, or an alloy of two or more of these materials. Less noble substrates such as copper or nickel may receive a conductive and protective coating against oxidation.

[0151] The metal sheet can be coated with a noble metal layer, in particular selected from gold, platinum, palladium, titanium or alloys containing mainly at least one or more of these metals, or a layer of ITO type conductive material (which has the advantage of acting as a diffusion barrier).

[0152] In general, this substrate capable of acting as an electric current collector must withstand the conditions of heat treatment of the deposited layer, and the operating conditions within the battery cell. As such, copper and nickel are suitable in contact with the cathode material; they may oxidise the anode.

[0153] Regarding the deposition of the layers, the electrophoresis method (especially in water) can be used. In this particular case, the substrate is subjected to an electrochemical polarisation which leads either to its oxidation or to its dissolution in the suspension of nanoparticles. In this case, only substrates which do not have anodisation and/or corrosion phenomena can be used. This is in particular the case with stainless steel and noble metals.

[0154] When the deposition of nanoparticles and/or agglomerates is carried out by one of the other techniques mentioned below (such as coating, printing) then it is possible to broaden the choice of substrates. This choice will then be made rather depending on the stability of the metal at the operating potential of the electrodes which are associated therewith and upon contact with the electrolytes. However, depending on the synthetic route used to produce the nanoparticles, more or less aggressive heat treatments must be carried out for the consolidation and possible recrystallisation of the nanopowders: this aspect will be further explored in section 5 below.

[0155] In all cases, a consolidation heat treatment is necessary to obtain these mesoporous electrodes. It is essential that the substrate capable of acting as an electric current collector can withstand these heat treatments without being oxidised. Several strategies can be used.

[0156] When the nanopowders deposited on the substrate by inking are amorphous and/or with numerous point defects, it is necessary to carry out a heat treatment which, in addition to consolidation, will also allow to recrystallise the material in the correct crystalline phase with the correct stoichiometry. For this purpose, it is generally necessary to carry out heat treatments at temperatures between 500 and 700° C. The substrate will then have to withstand this type of heat treatment, and it is necessary to use materials that withstand these high temperature treatments. Strips of stainless steel, titanium, molybdenum, tungsten, tantalum, chromium, as well as their alloys can for example be used.

[0157] When the nanopowders and/or agglomerates are crystallised, obtained by hydrothermal or solvothermal synthesis with the correct phase and crystalline structure, then it is possible to use consolidation heat treatments under a controlled atmosphere, which will allow to use less noble substrates such as nickel, copper, aluminium, and due to the very small size of the primary particles obtained by hydrothermal synthesis, it is also possible to reduce the temperature and/or the duration of the consolidation heat treatment to values close to 350 - 500° C., which also allows a wider choice of substrates. However, these less noble substrates must withstand the heat treatment allowing to remove the organic additives possibly contained in the suspension of nanoparticles used such as ligands, stabilisers, binders or residual organic solvents (debinding), this heat treatment being advantageously carried out under an oxidising atmosphere.

[0158] It is also possible that pseudo-hydrothermal syntheses result in amorphous nanoparticles which will need to be recrystallised later.

[0159] These substrates capable of acting as an electric current collector can optionally be covered with a thin film of conductive oxide. This oxide may have the same composition as the electrode. These thin films can be produced by sol-gel. This oxide-based interface allows to limit the corrosion of the substrate and ensures a better attachment base for the electrode with the substrate.

[0160] With regard to the operating conditions within the battery cell, it should be noted first of all that in the batteries using porous electrodes according to the invention, the liquid electrolytes which impregnate the porous electrode are in direct contact with the substrate capable of acting as a current collector. However, when these electrolytes are in contact with substrates capable of acting as a current collector, that is to say substrates which are metallic and polarised at potentials which are very anodic for the cathode and very cathodic for the anode, these electrolytes are capable of inducing a dissolution of the current collector. These parasitic reactions can degrade the battery life and accelerate its self-discharge. To avoid this, substrates capable of acting as a current collector such as aluminium current collectors are used at the cathode in all lithium-ion batteries. Aluminium has this peculiarity of being anodised at very anodic potentials, and the oxide layer thus formed at its surface protects it from the dissolution. However, aluminium has a melting temperature close to 600° C. and cannot be used for the manufacture of batteries according to the invention, if the electrode consolidation treatments may melt the current collector.

[0161] Thus, to avoid parasitic reactions that can degrade the life of the battery and accelerate its self-discharge, a titanium strip is advantageously used as a current collector at the cathode. When operating the battery, the titanium strip, such as aluminium, will be anodised and its oxide layer will prevent any parasitic reactions of titanium dissolution in contact with the liquid electrolyte. In addition, as titanium has a much higher melting point than aluminium, fully solid electrodes according to the invention can be made directly on this type of strip.

[0162] The use of these massive materials, in particular titanium, copper or nickel strips, also allows to protect the cutting edges of the battery electrodes from corrosion phenomena.

[0163] Stainless steel can also be used as a current collector, especially when containing titanium or aluminium as an alloy element, or when it has a thin layer of protective oxide.

[0164] Other substrates serving as a current collector can be used such as less noble metal strips covered with a protective coating, allowing to avoid the possible dissolution of these strips induced by the presence of electrolytes to their contact.

[0165] These less noble metal strips can be Copper, Nickel or metal alloy strips such as stainless steel strips, Fe—Ni alloy, Be—Ni—Cr alloy, Ni—Cr alloy or Ni—Ti alloy strips.

[0166] The coating that can be used to protect the substrates serving as current collectors may be of different natures. It may be: [0167] a thin layer obtained by the sol-gel method of the same material as that of the electrode. The absence of porosity in this film allows to prevent contacts between the electrolyte and the metal current collector; [0168] a thin layer obtained by vacuum deposition, in particular by Physical Vapour Deposition (abbreviated PVD) or by Chemical Vapour Deposition (abbreviated CVD), of the same material as that of the electrode; [0169] a thin metal layer, which is dense, flawless, such as a thin metal layer of gold, titanium, platinum, palladium, tungsten or molybdenum. These metals can be used to protect current collectors as they have good conduction properties and can withstand heat treatments during the subsequent electrode manufacturing method. This layer can in particular be produced by electrochemistry, PVD, CVD, evaporation, ALD; [0170] a thin carbon layer such as diamond, graphite carbon, deposited by ALD, PVD, CVD or inking of a sol-gel solution allowing to obtain after heat treatment a carbon-doped inorganic phase to make it conductive; [0171] a layer of conductive or semiconductor oxides, such as an ITO (indium-tin oxide) layer only deposited on the cathode substrate because the oxides are reduced at low potentials; and [0172] a layer of conductive nitrides such as a TiN layer only deposited on the cathode substrate because nitrides insert lithium at low potentials.

[0173] The coating that can be used to protect the substrates serving as current collectors must be electronically conductive so as not to interfere with the operation of the electrode subsequently deposited on this coating, by making it too resistive.

[0174] In general, in order not to impact too heavily the operation of the battery cells, the maximum dissolution currents measured on the substrates which can act as a current collector, at the operating potentials of the electrodes, expressed in .Math.A/cm.sup.2, must be 1000 times lower than the surface capacities of the electrodes expressed in .Math.Ah/cm.sup.2. When seeking to increase the thickness of the electrodes, it is observed that the shrinkage generated by consolidation can lead either to cracking of the layers or to a shear stress at the interface between the substrate (which has a fixed dimension) and the ceramic electrode. When this shear stress exceeds a threshold, the layer detaches from its substrate.

[0175] To avoid this phenomenon, it is preferable to increase the thickness of the electrodes by a succession of deposition - sintering operations. This first variant of the first embodiment of the deposition of the layers gives a good result, but is not very productive. Alternatively, in a second variant, layers of greater thickness are deposited on both faces of a perforated substrate. The perforations must be of sufficient diameter so that the two layers of the front and back are in contact at the perforations. Thus, during consolidation, the nanoparticles and/or agglomerates of nanoparticles of electrode material in contact through the perforations in the substrate are welded together, forming an attachment point (welding point between the depositions of the two faces). This limits the loss of adhesion of the layers to the substrate during the consolidation steps.

[0176] To avoid this phenomenon, that is to say in order to increase the deposition thicknesses while limiting or eliminating the appearance of cracks, it is possible to add binders, dispersants. These additives and organic solvents can be eliminated by heat treatment, preferably under oxidising atmosphere, such as by debinding, during a sintering treatment or during a heat treatment carried out prior to the sintering treatment.

3.2 Intermediate Substrate

[0177] According to a second embodiment, the electrode layers are not deposited on a substrate capable of acting as an electric current collector, but on an intermediate, temporary substrate. In particular, it is possible to deposit, from suspensions that are more concentrated in nanoparticles and/or agglomerates of nanoparticles (that is to say less fluid, preferably pasty), fairly thick layers (called “green sheet”). These thick layers are deposited for example by a coating method, preferably by a doctor blade coating (a technique known under the term “tape casting”) or a slot-die coating. Said intermediate substrate may be a polymeric sheet, for example poly(ethylene terephthalate), abbreviated PET. During drying, these layers do not crack, in particular when drying occurs after the separation of the layer obtained in step (b) from its intermediate substrate. For consolidation by heat treatment (and preferably already for drying) they can be detached from their substrate; plates are thus obtained after cutting electrodes called “raw” electrodes which after calcination heat treatment and partial sintering will give mesoporous and self-supporting ceramic plates.

[0178] A stack of three layers is then made, namely two plates of electrodes of the same polarity separated by an electrically conductive sheet capable of acting as an electric current collector, such as a metal sheet or a graphite sheet. This stack is then assembled by a thermomechanical treatment, comprising a pressing and a heat treatment, preferably carried out simultaneously. Alternatively, to facilitate gluing between the ceramic plates and the metal sheet, the interface may be coated with a layer allowing electronically conductive gluing. This layer can be a sol-gel layer (preferably of the type allowing the chemical composition of the electrodes to be obtained after heat treatment) possibly loaded with particles of an electronically conductive material, which will make a ceramic weld between the mesoporous electrode and the metal sheet. This layer can also consist of a thin layer of non-sintered electrode nanoparticles, or of a thin layer of a conductive glue (loaded with graphite particles for example), or else a metallic layer of a metal having a low melting point.

[0179] When said electrically conductive sheet is metallic, it is preferably a laminated sheet, that is to say obtained by lamination. The lamination may optionally be followed by a final annealing, which can be a (total or partial) softening or recrystallisation annealing, depending on the terminology of metallurgy. It is also possible to use an electrochemically deposited sheet, for example an electrodeposited copper sheet or an electrodeposited nickel sheet.

[0180] In any case, a ceramic electrode is obtained, without organic binder, which is mesoporous, located on either side of a metal substrate serving as an electronic current collector.

4. Deposition of the Layers of Active Material P

[0181] In general, and as has already been mentioned, the electrodes according to the invention can be manufactured from suspensions of nanoparticles, using known coating techniques. These techniques which can be used are tape casting and coating techniques, such as roll coating, doctor blade coating, slot-die coating, curtain coating. Dip-coating can also be used.

[0182] For all these techniques, it is advantageous for the dry extract of the suspension to be greater than 20%, and preferably greater than 40%; this decreases the risk of cracking when drying.

[0183] Printing techniques can also be used, such as flexographic techniques, ink-jet printing. Electrophoresis can also be used.

[0184] In a first embodiment, the method according to the invention advantageously uses the electrophoresis of suspensions of nanoparticles as a technique for depositing porous, preferably mesoporous, electrode layers. The method for depositing layers of electrodes from a suspension of nanoparticles is known as such (See, for example, European Patent Publication No. EP 2 774 194 B1). The substrate can be metallic, for example a metallic sheet. The substrate serving as a current collector within the batteries using porous electrodes according to the invention is preferably selected from strips of titanium, copper, stainless steel or molybdenum.

[0185] As a substrate, for example, a sheet of stainless steel with a thickness of 5 .Math.m can be used. The metal sheet may be coated with a layer of noble metal, in particular selected from gold, platinum, palladium, titanium or alloys predominantly containing at least one or more of these metals, or with a layer of ITO type conductive material (which has the advantage of also acting as a diffusion barrier).

[0186] In a particular embodiment, a layer, preferably a thin layer, of an electrode material is deposited on the metal layer; this deposition must be very thin (typically a few tens of nanometres, and more generally comprised between 10 nm and 100 nm). It can be carried out by a sol-gel method. For example, LiMn.sub.2O.sub.4 can be used for a porous LiMn.sub.2O.sub.4 cathode.

[0187] For electrophoresis to take place, a counter electrode is placed in the suspension and a voltage is applied between the conductive substrate and said counter electrode.

[0188] In an advantageous embodiment, the electrophoretic deposition of the aggregates or agglomerates of nanoparticles is carried out by galvanostatic electrodeposition in pulsed mode; high frequency current pulses are applied, this avoids the formation of bubbles on the surface of the electrodes and the variations of the electric field in the suspension during the deposition. The thickness of the electrode layer thus deposited by electrophoresis, preferably by galvanostatic electrodeposition in pulsed mode is advantageously less than 10 .Math.m, preferably less than 8 .Math.m, and is even more preferably between 1 .Math.m and 6 .Math.m.

[0189] To deposit layers that are quite thick by electrophoresis, carbon black nanoparticles can be added to the suspension to improve the electronic conduction of the deposition before consolidation. These carbon black nanoparticles will be removed by oxidation during the consolidation heat treatment.

[0190] In another embodiment, aggregates or agglomerates of nanoparticles can be deposited by the dip-coating method, regardless of the chemical nature of the nanoparticles used. This deposition method is preferred when the nanoparticles used have little or no electric charge. In order to obtain a layer of the desired thickness, the step of depositing by dip-coating the aggregates or agglomerates of nanoparticles followed by the step of drying the resulting layer are repeated as necessary. In order to increase the thickness of the layers free of cracks, it is advantageous to use in the colloidal suspension or the deposited paste, at least one organic additive such as ligands, stabilisers, thickeners, binders or residual organic solvents. Although this succession of dip-coating/drying steps is time consuming, the dip-coating deposition method is a method which is simple, safe, easy to implement, to industrialise and allowing to obtain a homogeneous and compact final layer.

5. Consolidation Treatment of the Deposited Layers

[0191] The deposited layers must be dried; drying must not induce the formation of cracks. For this reason, it is preferred to carry it out under controlled humidity and temperature conditions or to use, to produce the porous layer, colloidal suspensions and/or pastes comprising, in addition to aggregates or agglomerates of monodisperse primary nanoparticles, at least one electrode active material P according to the invention, organic additives such as ligands, stabilisers, thickeners, binders or residual organic solvents.

[0192] The dried layers can be consolidated by a pressing and/or heating step (heat treatment). In a very advantageous embodiment of the invention, this treatment leads to a partial coalescence of the primary nanoparticles in the aggregates, or agglomerates, and between neighbouring aggregates or agglomerates; this phenomenon is called “necking” or “neck formation”. It is characterised by the partial coalescence of two particles in contact, which remain separate but connected by a (constricted) neck; this is illustrated schematically in FIGS. 3 and 4. Lithium ions and electrons are movable within these necks and can diffuse from particle to particle without encountering grain boundaries. The nanoparticles (FIG. 3) are welded together to ensure the conduction of electrons from one particle to another (FIG. 4). Thus, a continuous mesoporous film forming a three-dimensional network with high ionic mobility and electronic conduction, is formed from the primary nanoparticles; this network includes interconnected pores, preferably mesopores.

[0193] The temperature necessary to obtain “necking” depends on the material; taking into account the diffusive nature of the phenomenon which leads to necking, the duration of the treatment depends on the temperature. This method can be called sintering; depending on its duration and temperature, a more or less pronounced coalescence (necking) is obtained, which has repercussions on the porosity. It is thus possible to go down to 30% (or even 25%) of porosity while maintaining a perfectly homogeneous channel size.

[0194] The heat treatment can also be used to eliminate the organic additives possibly contained in the suspension of nanoparticles used, such as ligands, stabilisers, binders or residual organic solvents. According to another variant, an additional heat treatment, under an oxidising atmosphere, can be carried out to remove these organic additives possibly contained in the suspension of nanoparticles used. This additional heat treatment is advantageously carried out on the porous layer separated from its intermediate substrate, when such a substrate is used. This additional heat treatment is advantageously carried out before the consolidation treatment of step c) allowing to obtain a porous, preferably mesoporous, layer.

6. Deposition of the Coating of Electronically Conductive Material

[0195] According to an essential feature of the present invention, a coating of an electronically conductive material is deposited on and inside the pores of said porous layer.

[0196] Indeed, as explained above, the method according to the invention, which necessarily involves a step of depositing agglomerated nanoparticles of electrode material (active material), causes the nanoparticles to “weld” naturally to each other to generate, after consolidation such as annealing, a porous, rigid, three-dimensional structure, without organic binder; this porous, preferably mesoporous, layer, is perfectly adapted to the application of a surface treatment, by gas or liquid, which goes deep into the open porous structure of the layer.

[0197] Very advantageously, this deposition is carried out by a technique allowing an encapsulating coating (also called “conformal deposition”), a deposition which faithfully reproduces the atomic topography of the substrate on which it is applied, and which goes deep into the open porosity network of the layer. Said electronically conductive material may be carbon.

[0198] The techniques of ALD (Atomic Layer Deposition) or CSD (Chemical Solution Deposition), known as such, may be suitable. They can be implemented on the porous layers after manufacture, before the deposition of the separator particles and before the assembly of the cell. The ALD deposition technique is carried out layer by layer, by a cyclic method, and allows to produce an encapsulating coating which faithfully reproduces the topography of the substrate; the coating lines the entire surface of the electrodes. This encapsulating coating typically has a thickness comprised between 1 nm and 5 nm.

[0199] The deposition by ALD is carried out at a temperature typically comprised between 100° C. and 300° C. It is important that the layers are free from organic matter: they must not include any organic binder, any residues of stabilising ligands used to stabilise the suspension must have been removed by purification of the suspension and/or during the heat treatment of the layer after drying. Indeed, at the temperature of the ALD deposition, the organic materials forming the organic binder (for example the polymers contained in the electrodes produced by ink tape casting) risk decomposing and will pollute the ALD reactor. Moreover, the presence of residual polymers in contact with the electrode active material particles can prevent the ALD coating from encapsulating all the particle surfaces, which impairs its effectiveness.

[0200] The CSD deposition technique also allows to produce an encapsulating coating with a precursor of the electronically conductive material which faithfully reproduces the topography of the substrate; it lines the entire surface of the electrodes. This encapsulating coating typically has a thickness of less than 5 nm, preferably comprised between 1 nm and 5 nm. It must then be transformed into an electronically conductive material. In the case of a carbon precursor, this will be done by pyrolysis, preferably under inert gas (such as nitrogen).

[0201] In this variant of depositing a nanolayer of electronically conductive material, it is preferable that the diameter D50 of the primary particles of electrode material is at least 10 nm in order to prevent the conductive layer from blocking the open porosity of the electrode layer.

7. Electrolyte

[0202] The electrolyte is not part of the present invention, but it is useful to mention it here because it is needed to form the battery cell. The electrode according to the invention does not contain organic compounds. This absence of organic compounds coupled to a mesoporous structure promotes wetting by an electrolyte which conducts lithium ions. This electrolyte can then be selected without distinction from the group formed of: an electrolyte composed of aprotic solvents and lithium salts, an electrolyte composed of ionic liquids or poly(ionic liquids) and lithium salts, a mixture of aprotic solvents and ionic liquids or poly(ionic liquids) and lithium salts, a polymer made ionically conductive containing lithium salts, an ionically conductive polymer.

[0203] Said ionic liquids can be salts molten at room temperature (these products are known under the designation RTIL, Room Temperature Ionic Liquid), or ionic liquids which are solid at room temperature. These ionic liquids which are solid at room temperature must be heated in order to liquefy them in order to impregnate the electrodes; they are solidified in the electrode. Said ionically conductive polymer can be melted to be mixed with the lithium salt and this molten phase can then be impregnated into the mesoporosity of the electrode.

[0204] Likewise, said polymer can be a liquid at room temperature, or else a solid, which is then heated to make it liquid in order to impregnate it in the mesoporous electrode.

8. Examples of Advantageous Embodiments

[0205] In general, when the lithium-ion battery has to operate at high temperature, use is advantageously made, as the material P for the cathode, of one of the materials listed above from those which does not contain manganese, such as LiFePO.sub.4 or LiCoPO.sub.4. The anode in this case is advantageously a titanate, a mixed oxide of titanium and niobium or a derivative of a mixed oxide of titanium and niobium, and the cell is impregnated with an ionic liquid including a lithium salt. If said ionic liquid includes sulphur atoms, it is preferred that the substrate is a noble metal.

[0206] To enable the person skilled in the art to carry out the method according to the invention, some embodiments and examples of electrodes according to the invention are given here.

[0207] In a first advantageous embodiment, a mesoporous anode is manufactured according to the invention for a lithium-ion battery with a suspension of material P which is Li.sub.4Ti.sub.5O.sub.12 or Li.sub.4Ti.sub.5-xM.sub.xO.sub.12 with M = V, Zr, Hf, Nb, Ta. FIG. 1 shows a typical X-ray diffractogram of the Li.sub.4Ti.sub.5O.sub.12 nanopowder used in the suspension, FIG. 2 shows a picture obtained by transmission electron microscopy of these primary nanoparticles.

[0208] This material is deposited on a metal substrate, which is heat treated (sintered) and covered with a layer of an electronically conductive material a few nanometres thick; this layer is called here “nanocoating”. This nanocoating is preferably carbon. This carbon nanocoating can be produced by impregnation with a carbon-rich liquid phase, which is then pyrolysed under nitrogen, or else by ALD deposition. These anodes insert lithium at a potential of 1.55 V, are very powerful and allow ultra-fast recharging.

[0209] In a second advantageous embodiment, a mesoporous anode according to the invention is manufactured for a lithium-ion battery with a material P which is TiNb.sub.2O.sub.7 or Li.sub.wTi.sub.1-xM.sup.1.sub.xNb.sub.2-yM.sup.2.sub.yO.sub.7, wherein M.sup.1 and M.sup.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.sup.1 and M.sup.2 can be identical or different from each other, and wherein 0 ≤ w ≤ 5, 0 ≤ x ≤ 1, 0 ≤ y ≤ 2. This layer is deposited on a metal substrate, sintered and covered with an electronically conductive nanocoating, which is advantageously carbon, deposited as described in relation to the previous embodiment. These anodes are very powerful and allow rapid recharging. In a third advantageous embodiment, a mesoporous anode is manufactured according to the invention for a lithium-ion battery with a material P which is Nb.sub.2O.sub.5±δ or Nb.sub.18W.sub.16O.sub.93±δ or Nb.sub.16W.sub.5O.sub.55±δ with 0 ≤ x < 1 and 0 ≤ δ ≤ 2, or La.sub.xTi.sub.1-.sub.2xNb.sub.2+xO.sub.7 where 0<x<0.5; or Ti.sub.1-.sub.xGe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7±z or Li.sub.wTi.sub.1-xGe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7±z or Ti.sub.1-xCe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7±z or Li.sub.wTi.sub.1-xCe.sub.xNb.sub.2-.sub.yM.sup.1.sub.yO.sub.7±z wherein M.sup.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 and where 0 ≤ w ≤ 5 and 0 ≤ x ≤ 1 and 0 ≤ y ≤ 2 and z ≤ 0.3; or Ti.sub.1-xGe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7-.sub.zM.sup.2.sub.z or Li.sub.wTi.sub.1-xGe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7-zM.sup.2.sub.z or Ti.sub.1-xCe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7-z M.sup.2.sub.z or Li.sub.wTi.sub.1-xCe.sub.xNb.sub.2-yM.sup.1.sub.yO.sub.7-.sub.zM.sup.2.sub.zwherein M.sup.1 and M.sup.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.sup.1 and M.sup.2 may be identical or different from each other, and wherein 0 ≤ w ≤ 5 and 0 ≤ x ≤ 1 and 0 ≤ y ≤ 2 and z ≤ 0.3. This layer is deposited on a metallic substrate, sintered and covered with an electronically conductive nanocoating, which is advantageously carbon, deposited as described in relation to the previous embodiment. These anodes are very powerful and allow rapid recharging.

[0210] In a fourth embodiment, a mesoporous anode is manufactured according to the invention for a lithium-ion battery with a material P which is TiNb.sub.2O.sub.7-zM.sup.3.sub.z or Li.sub.wTi.sub.1-.sub.xM.sup.1.sub.xNb.sub.2-yM.sup.2.sub.yO.sub.7-zM.sup.3.sub.z wherein M.sup.1 and M.sup.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.sup.1 and M.sup.2 can be identical or different from each other. The relationship 0 ≤ w ≤ 5, 0 ≤ x ≤ 1, and 0 ≤ y ≤ 2 is applied. M.sup.3 is at least one halogen and z ≤ 0.3. As described in relation to the second embodiment, this layer is deposited on a metal substrate, sintered and covered with a nanocoating, which may be carbon, deposited as described above. These anodes are very powerful and are capable of rapid recharges.

[0211] In a fifth embodiment, a mesoporous anode is manufactured according to the invention for a lithium-ion battery with a material P which is TiO.sub.2 or LiSiTON; the manufacture is carried out as described in relation to the other embodiments. These electrodes are very powerful and are capable of rapid recharges.

[0212] In a sixth exemplary embodiment, a mesoporous cathode is manufactured according to the invention for a lithium-ion battery with a material P which is LiMn.sub.2O.sub.4; these nanoparticles can be obtained by hydrothermal synthesis using the procedures described in the article “One pot hydrothermal synthesis and electrochemical characterisation of Li.sub.1+xMn.sub.2-yO.sub.4 spinel structured compounds”, published in the journal Energy Environ. Sci., 3, p. 1339-1346. In this synthesis, a small amount of PVP was added in order to adjust the size and shape of the agglomerates obtained. The latter are spherical in shape and approximately 150 nm in diameter, consisting of primary particles comprised between 10 nm and 20 nm in size. After centrifugation and washing, about 10 to 15% by mass of PVP 360k were added to the aqueous suspension and the water was evaporated to obtain a dry extract of 10%. The ink thus obtained was applied to a sheet of stainless steel and then dried to obtain a layer of approximately 10 microns. This sequence can be repeated several times to increase the thickness of the deposition. The deposition thus obtained was annealed for 1 hour at 600° C. under air in order to consolidate the agglomerates of nanoparticles to each other.

[0213] This mesoporous layer was then impregnated with a sucrose solution, then annealed at 400° C. under nitrogen to obtain an electronically conductive carbon layer over the entire mesoporous surface of the electrode; the thickness of this carbon layer was of a few nanometres. The electrolyte layer, in this case Li.sub.3PO.sub.4, which will subsequently be impregnated, was then deposited on this mesoporous cathode. In a sixth exemplary embodiment, a battery is manufactured according to the invention, said battery is formed of: [0214] a mesoporous anode (50% porosity) comprising Li.sub.4Ti.sub.5O.sub.12 and/or TiO.sub.2, [0215] a mesoporous cathode (50% porosity) comprising LiMn.sub.2O.sub.4, [0216] a mesoporous electrolytic separator (50% porosity) comprising Li.sub.3PO.sub.4.

[0217] The electrode substrates were made of 316L stainless steel. The ionic impregnation liquid was a mixture of 1-butyl-1-methylpyrrolidinium bis(trifluoromethane sulfonyl)imide (abbreviated Pyr14TFSI) and lithium bis(fluorosulfonyl)imide (abbreviated LiTFSI) at 0.7 M.

[0218] FIG. 5 shows the evolution of the relative capacity of a battery according to the invention depending on the number of charge and discharge cycles; each discharge was carried out to a depth of 100% of the battery capacity. It is observed that there is no loss of the relative capacity of the battery; the battery according to the invention has an excellent durability in terms of charge-discharge cycles.

[0219] FIG. 6 shows a recharging curve of this battery. It is seen that 80% of the battery capacity can be recharged in just less than 5 minutes; this rapid recharging capacity is of enormous application benefit.