Magnetic lithium titanate

Abstract

The present invention relates to a product, the crystallized part of which comprises crystallized phase Li2TiO3 comprising the elements Mn and Fe, said product comprising at least the elements Li, Ti, Fe, Mn and O, the elements Li, Ti, Fe and Mn being present in said product in the following amounts, determined by inductively coupled plasma spectrometry and stated in percentages by weight: - 11% < Li < 15%, - 28% < Ti < 45%, - 0.1% < Mn < 12%, - 0.15% < Fe < 9%, the mass ratio (Mn + Fe) / Ti being such that: 0.03 ≤ (Mn + Fe) / Ti ≤ 0.5.

Description

[0001] Description

[0002] Title: Magnetic Lithium Titanate

[0003] technical field

[0004] The present invention relates to a product comprising a magnetic lithium titanate and to a method of manufacturing a product comprising a magnetic lithium titanate.

[0005] Previous technique

[0006] The use of lithium, particularly in batteries, is constantly increasing.

[0007] Lithium can be extracted from a liquid source, for example brine.

[0008] This extraction, or capture, can be carried out by placing a lithium-absorbing material, generally in the form of shaped objects or in the form of a powder, in contact with said liquid source containing lithium, said material selectively and reversibly capturing lithium when said liquid source is in contact with it.

[0009] The lithium-absorbing material is then separated from the liquid source using various techniques.

[0010] Then, the lithium is recovered by bringing the lithium-laden material into contact with slightly acidified water. This results in a concentrated lithium solution, which is purified before a precipitation step, usually in the form of lithium carbonate. A separation step between the lithium-absorbing material and the concentrated lithium solution is then necessary.

[0011] These separation steps are long and costly.

[0012] Lithium titanate (Li₂TiO₂) is a material known to selectively capture lithium after activation. It is classically activated by at least partial replacement of the lithium in its structure with protons; this partial replacement is referred to as the at least partial protonation step of Li₂TiO₂. Li₂TiO₂ that has undergone this protonation step is classically designated by the formula hLTiCh.

[0013] It is known from "Superior lithium adsorption and required magnetic separation behavior of iron-doped lithium ion sieves", Wang et Al., Chemical Engineering Journal 332 (2018), pp160-168, that Li2TiOs made magnetic by iron doping can be activated, the solubility limit of iron in Li2TiOs being reached for an atomic ratio Fe / Ti equal to 0.15. The separation of this material from liquids is facilitated and accelerated by the application of a magnetic field.

[0014] There is a need for a lithium-absorbing material with high magnetic properties, enabling a simpler and more economical separation process.

[0015] One objective of the invention is to address, at least partially, this need. Summary of the invention

[0016] According to the invention, this goal is achieved by means of a product whose crystallized part comprises, preferably consisting essentially of, a Li2TiC>3 crystallized phase comprising the elements Mn and Fe (the elements Fe and Mn being typically called dopants), said product comprising at least the elements Li, Ti, Fe, Mn and O, the elements Li, Ti, Fe, Mn being present in said product in the following amounts, determined by inductively coupled plasma spectrometry and as weight percentages:

[0017] 11% < Li < 15%,

[0018] 28% < Ti < 45%,

[0019] 0.1% < Mn < 12%,

[0020] 0.15% < Fe < 9%, the mass ratio (Mn+Fe) / Ti being such that: 0.03 < (Mn+Fe) / Ti < 0.5.

[0021] The inventors discovered that the iron- and manganese-doped product according to the invention exhibits magnetic properties equal to or greater than those of a prior art iron-doped Li2TiOa product and / or a reduction in sintering temperature, at equivalent doping levels. The same is true after activation by at least partial protonation.

[0022] According to preferred but non-limiting embodiments of the present invention, which may, where appropriate, be combined with each other: the product has the following chemical analysis, determined by inductively coupled plasma spectrometry, in weight percentages:

[0023] - 11% < Li < 15%, and

[0024] - 28% < Ti < 45%, and

[0025] - 0.1% < Mn < 12%, and

[0026] - 0.15% < Fe < 9%, and

[0027] Elements other than Li, Ti, Fe, Mn and O in a content of less than 3%, and

[0028] O in a content corresponding to the complement to 100%; the Li content is greater than or equal to 11.5% and / or less than or equal to 13.5% (in weight percentages); the Ti content is greater than or equal to 33% and / or less than or equal to 41% (in weight percentages); the Mn content is greater than or equal to 1% and / or less than or equal to 8% (in weight percentages); the Fe content is greater than or equal to 1% and / or less than or equal to 8% (in weight percentages); the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.18; the sum of the Fe and Mn contents, Mn+Fe, is greater than 4.4% (in weight percentages);the mass ratio Mn / (Mn+Fe) is greater than or equal to 0.15, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.18 and less than 0.24, and the mass ratio Mn / (Mn+Fe) is greater than or equal to 0.4, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.24 and less than 0.36, and the mass ratio Mn / (Mn+Fe) is greater than or equal to 0.7, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.36; substantially all of the manganese present in the product is in an oxidation state of +2; substantially all of the manganese present in the product is in an oxidation state of +3; substantially all of the manganese present in the product is in an oxidation state of +4; substantially all of the manganese present in the product is partly in an oxidation state of +2 and partly in an oxidation state of +3;substantially all of the manganese present in the product is partly in an oxidation state of +2 and partly in an oxidation state of +4; substantially all of the manganese present in the product is partly in an oxidation state of +3 and partly in an oxidation state of +4; substantially all of the manganese present in the product is partly in an oxidation state of +2, partly in an oxidation state of +3 and partly in an oxidation state of +4; the crystalline phase Li2TiOa containing the elements Mn and Fe has an average crystallite size less than or equal to 90 nm.

[0029] The invention also relates to a method for manufacturing a product according to the invention and as previously described, comprising the following steps: a) preparing a particulate mixture having a composition suitable for obtaining, at the end of step f), a product according to the invention; b) optionally, drying said particulate mixture; c) optionally, preparing a starting feed from said particulate mixture, optionally dried; d) optionally, shaping the starting feed; e) optionally, drying; f) heat treatment at a temperature above 500°C and below 850°C so as to obtain the product according to the invention. Preferred but not limiting embodiments of the present invention may, where appropriate, be combined with each other:

[0030] - in step a), the particulate mixture has a 90th percentile of less than 10 pm, preferably less than 2 pm;

[0031] - in step a), the raw material powders are co-ground;

[0032] - at step f), the temperature is greater than 520°C, preferably greater than 540°C and less than 800°C, preferably less than 750°C;

[0033] - at step f), the duration of holding at the temperature plateau is greater than 30 minutes and less than 10 hours;

[0034] - in step a), substantially all of the manganese is supplied by the oxide MnO;

[0035] - at step a), substantially all of the manganese is supplied by the oxide Mn2C>3;

[0036] - at step a), substantially all of the manganese is supplied by the oxide MnO2;

[0037] - in step a), substantially all of the manganese is supplied by the oxide MnsCl;

[0038] - in step a), substantially all of the manganese is supplied by a mixture of the oxides MnO and Mn2Oa;

[0039] - in step a), substantially all of the manganese is supplied by a mixture of the oxides MnO and MnO2;

[0040] - at step a), substantially all of the manganese is supplied by a mixture of the oxides MnO, Mn2Os, Mn3C>4 and MnO2;

[0041] - in step a), substantially all of the manganese is supplied by a mixture of the oxides Mn3C>4 and MnO2;

[0042] - in step a), substantially all of the manganese is supplied by a mixture of the oxides MnO, Mn2Oa and MnO2.

[0043] The invention also relates to a manufacturing process comprising the steps of the process as described in this application and further comprising an additional step (g) consisting of at least partial protonation of the product obtained at the end of step (f). Protonation consists of replacing at least a portion of the lithium (Li) + of the product according to the invention by protons H +in order to activate the product, that is, so that it can capture the lithium present in a liquid source.

[0044] This protonation is classic and can be achieved in particular by placing the product according to the invention in contact with an acidic liquid.

[0045] The invention also relates to the product obtained at the end of said step g).

[0046] The invention also relates to a lithium capture device, in particular a stirred reactor, comprising a product according to the invention or a product obtained by the process according to the invention as described above. Definitions:

[0047] The 50th (D50) and 90th (D90) percentiles of a powder are defined as the particle sizes corresponding to the 50% and 90%, respectively, by volume, of the cumulative particle size distribution curve of the powder, with these particle sizes listed in ascending order. According to this definition, 90% by volume of the powder's particles have a size less than or equal to D90.

[0048] Percentiles can be determined from a particle size distribution of a powder obtained using a laser particle size analyzer.

[0049] In this application, the term "include" is equivalent to "comprehensive".

[0050] DETAILED DESCRIPTION

[0051] A product according to the invention has one or more of the following optional characteristics:

[0052] The elements Li, Ti, Fe, Mn are present in the said product, in the following concentrations, as percentages by weight:

[0053] Li: preferably greater than or equal to 11.2%, preferably greater than or equal to 11.5%, preferably greater than or equal to 12%, and / or preferably less than or equal to 14%, preferably less than or equal to 13.5%, preferably less than or equal to 13%, and

[0054] Ti: preferably greater than or equal to 29%, preferably greater than or equal to 30%, preferably greater than or equal to 31%, preferably greater than or equal to 32%, preferably greater than or equal to 33%, preferably greater than or equal to 34%, and / or preferably less than or equal to 44%, preferably less than or equal to 43%, preferably less than or equal to 42%, preferably less than or equal to 41%, preferably less than or equal to 40%, and

[0055] Mn: preferably greater than or equal to 0.5%, preferably greater than or equal to 1%, preferably greater than or equal to 1.5%, preferably greater than or equal to 2%, preferably greater than or equal to 2.5%, and / or preferably less than or equal to 11%, preferably less than or equal to 10%, preferably less than or equal to 9%, preferably less than or equal to 8%, preferably less than or equal to 7%, preferably less than or equal to 6%, preferably less than or equal to 5%, and

[0056] Fe: preferably greater than or equal to 0.2%, preferably greater than or equal to 0.3%, preferably greater than or equal to 0.4%, preferably greater than or equal to 0.5%, preferably greater than or equal to 0.6%, preferably greater than or equal to 1%, preferably greater than or equal to 1.5%, preferably greater than or equal to 2%, and / or preferably less than or equal to 8%, preferably less than or equal to 7%, preferably less than or equal to 6%, preferably less than or equal to 5%;

[0057] The following chemical analysis, determined by inductively coupled plasma spectrometry, is expressed as weight percentages:

[0058] Li in a content greater than 11%, preferably greater than or equal to 11.2%, preferably greater than or equal to 11.5%, preferably greater than or equal to 12%, and / or less than 15%, preferably less than or equal to 14%, preferably less than or equal to 13.5%, preferably less than or equal to 13%, and

[0059] Ti in a content greater than 28%, preferably greater than or equal to 29%, preferably greater than or equal to 30%, preferably greater than or equal to 31%, preferably greater than or equal to 32%, preferably greater than or equal to 33%, preferably greater than or equal to 34%, and / or less than 45%, preferably less than or equal to 44%, preferably less than or equal to 43%, preferably less than or equal to 42%, preferably less than or equal to 41%, preferably less than or equal to 40%, and

[0060] Mn in a content greater than 0.1%, preferably greater than or equal to 0.5%, preferably greater than or equal to 1%, preferably greater than or equal to 1.5%, preferably greater than or equal to 2%, preferably greater than or equal to 2.5%, and / or less than 12%, preferably less than or equal to 11%, preferably less than or equal to 10%, preferably less than or equal to 9%, preferably less than or equal to 8%, preferably less than or equal to 7%, preferably less than or equal to 6%, preferably less than or equal to 5%, and Fe in a content greater than 0.15%, preferably greater than or equal to 0.2%, preferably greater than or equal to 0.3%, preferably greater than or equal to 0.4%, preferably greater than or equal to 0.5%, preferably greater than or equal to 0.6%, preferably greater than or equal to 1%, preferably greater than or equal to 1%. 0.5%, preferably greater than or equal to 2%, and / or less than 9%, preferably less than or equal to 8%,preferably less than or equal to 7%, preferably less than or equal to 6%, preferably less than or equal to 5%, and,

[0061] Elements other than Li, Ti, Mn, Fe and O in a content of less than 3%, preferably less than 2%, preferably less than 1.5%, preferably less than 1%, preferably less than 0.5%, and

[0062] O in a content corresponding to the complement to 100%; The mass ratio (Mn+Fe) / Ti is such that (Mn+Fe) / Ti > 0.05, preferably (Mn+Fe) / Ti > 0.1, preferably (Mn+Fe) / Ti > 0.15, preferably (Mn+Fe) / Ti > 0.18, preferably (Mn+Fe) / Ti > 0.2; The mass ratio (Mn+Fe) / Ti is such that (Mn+Fe) / Ti < 0.45, preferably (Mn+Fe) / Ti < 0.40, preferably (Mn+Fe) / Ti < 0.35, preferably (Mn+Fe) / Ti < 0.30;

[0063] Preferably, in order to achieve optimal magnetic properties and / or a lower sintering temperature, the mass ratio (Mn+Fe) / Ti is between 0.15 and 0.35, preferably between 0.20 and 0.30;

[0064] The sum of the contents (in percentages by weight) of iron and manganese, Mn+Fe, is preferably greater than 1.4%, preferably greater than 2.3%, preferably greater than 4.4%, preferably greater than 6.4%, preferably greater than 7.6%, preferably greater than 8.3%, and preferably less than 19.8%;

[0065] The mass ratio Mn / (Mn+Fe) is such that Mn / (Mn+Fe) > 0.09, preferably Mn / (Mn+Fe) > 0.1, preferably Mn / (Mn+Fe) > 0.2, preferably Mn / (Mn+Fe) > 0.3 and preferably Mn / (Mn+Fe) < 0.9, preferably Mn / (Mn+Fe) < 0.8, preferably Mn / (Mn+Fe) < 0.7;

[0066] The mass ratio Mn / (Mn+Fe) is greater than or equal to 0.7, preferably greater than or equal to 0.8, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.36;

[0067] The mass ratio Mn / (Mn+Fe) is greater than or equal to 0.4, preferably greater than or equal to 0.5, preferably greater than or equal to 0.6, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.24;

[0068] The mass ratio Mn / (Mn+Fe) is greater than or equal to 0.15, preferably greater than or equal to 0.2, preferably greater than or equal to 0.3, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.18;

[0069] In one embodiment, the mass ratio Mn / (Mn+Fe) is greater than or equal to 0.15, preferably greater than or equal to 0.2, preferably greater than or equal to 0.3, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.18 and less than 0.24, and the mass ratio Mn / (Mn+Fe) is greater than or equal to 0.4, preferably greater than or equal to 0.5, preferably greater than or equal to 0.6, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.24 and less than 0.36, and the mass ratio Mn / (Mn+Fe) is greater than or equal to 0.7, preferably greater than or equal to 0.8 when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.36;

[0070] Approximately all the manganese present, preferably all of it, is in an oxidation state of +2. The oxidation state of the manganese can be determined by X-ray fluorescence, synchrotron radiation, or any other known method; Approximately all the manganese present, preferably all of it, is in an oxidation state of +3;

[0071] Approximately all of the manganese, preferably all of the manganese, present is in an oxidation state of +4;

[0072] Approximately all of the manganese, preferably all of the manganese, present is partly in an oxidation state of +2 and partly in an oxidation state of +3;

[0073] Approximately all of the manganese, preferably all of the manganese, present is partly in an oxidation state of +2 and partly in an oxidation state of +4;

[0074] Approximately all of the manganese, preferably all of the manganese, present is partly in an oxidation state of +3 and partly in an oxidation state of +4;

[0075] Approximately all of the manganese present, preferably all of it, is partly in an oxidation state of +2, partly in an oxidation state of +3, and partly in an oxidation state of +4; the Li2TiOa crystalline phase containing the elements Mn and Fe has an average crystallite size of 90 nm or less, preferably 70 nm or less, preferably 50 nm or less, preferably 30 nm or less, and preferably 5 nm or greater. Advantageously, the lithium adsorption capacity of the product is improved.

[0076] A product according to the invention can be manufactured according to a process according to the invention comprising the steps a) to f) mentioned above.

[0077] In step a), a particulate mixture is prepared whose composition is adapted so that the product obtained at the end of step f) conforms to the invention.

[0078] The raw material powders are mixed intimately.

[0079] Raw material powders can be ground individually or, preferably, co-ground so that the resulting particulate mixture has a 90th percentile preferably below 10 µm, preferably below 5 µm, preferably below 3 µm, preferably below 2 µm, preferably below 1.5 µm, preferably below 1 µm. This grinding can be wet grinding or wet co-grinding, preferably wet co-grinding, preferably in water. Grinding or co-grinding, particularly wet grinding, can also be used to obtain an intimate mixture.

[0080] The particulate mixture contains constituents providing the elements Li, Fe, Mn, Ti, and O. In one embodiment, some of these constituents may provide at least two of said elements. Preferably, the constituents providing Li, Fe, Mn, Ti, and O are chosen from oxides and salts, preferably from oxides, carbonates, hydroxides, sulfates, nitrates, phosphates, and mixtures thereof.

[0081] Preferably, lithium is supplied in the form of a carbonate, a hydroxide, or mixtures thereof. Preferably, lithium is supplied in the form of a carbonate.

[0082] Preferably, titanium, iron and manganese are supplied in the form of oxides.

[0083] In one embodiment, the iron is supplied in the form of Fe2Û3, Fe3Û4 and mixtures thereof. Preferably, the iron is supplied substantially, preferably entirely, in the form of Fe2Û3.

[0084] In one embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by MnO oxide and / or a precursor of MnO. Preferably in said embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by MnO oxide.

[0085] In one embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by Mn2Os oxide and / or a precursor of Mn2O3. Preferably in said embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by Mn2Os oxide.

[0086] In one embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by MnU2 oxide and / or a precursor of MnU2. Preferably in said embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by MnCl2 oxide.

[0087] In one embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by Mn3O4 oxide and / or a precursor of MnsC. Preferably in said embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by MnsC oxide.

[0088] In one embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides MnO and Mn2Os and / or a mixture of precursors of these oxides. Preferably, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides MnO and Mn2O3.

[0089] In one embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides MnO and MnU2 and / or a mixture of precursors of these oxides. Preferably, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides MnO and MnU2. In another embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides MnO, MnO, Mn3U4 and MnO, and / or a mixture of precursors of these oxides. Preferably, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides MnO, Mn2U3, Mn3U4 and MnU2.

[0090] In one embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides Mn3U4 and MnU2 and / or a mixture of precursors of these oxides. Preferably, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides Mn3U4 and MnU2.

[0091] In one embodiment, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides MnO, Mn2Os and MnU2 and / or a mixture of precursors of these oxides. Preferably, substantially all of the manganese, preferably all of the manganese, is supplied by a mixture of the oxides MnO, Mn2U3 and MnU2.

[0092] In a preferred embodiment, the main source of manganese, preferably the only source of manganese, is Mn3Û4 and / or a precursor of Mn3Û4, preferably Mn3Û4, and the main source of iron, preferably the only source of iron, is Fe2Û3.

[0093] Preferably, the powders used each have a D50 of less than 5 pm, preferably less than 3 pm, preferably less than 2 pm, preferably less than 1 pm.

[0094] Preferably, no raw materials other than the constituents providing the elements Li, Fe, Mn, Ti and O are intentionally introduced into the particulate mixture, the other elements present being impurities.

[0095] In optional step b), the particulate mixture may be at least partially dried, for example in an oven or by spray drying, particularly if it was obtained by wet milling or if at least one of its constituents was obtained by wet milling. In one embodiment, the temperature and / or duration of step b) are adjusted so that the residual moisture content of the particulate mixture is less than 2%, or even less than 1.5% by weight (relative to the weight of the particulate mixture). In one embodiment, particularly when the particulate mixture contains an amount of solvent, preferably water, leading to a starting charge in step c) with an amount of solvent, preferably water, that is too high for the shaping process envisaged in step d), step b) is a partial drying step aimed at adapting the solvent content, preferably water, to the shaping process envisaged in step d).In step c), optional, a starting charge is prepared, preferably at room temperature, comprising the particulate mixture obtained at the end of step a) or at the end of step b) and, optionally, a solvent, preferably water, the quantity of which is adapted to the shaping method of step d), in particular by the existence of a step b).

[0096] As is well known to those skilled in the art, the starting charge is adapted to the shaping process of the optional step d).

[0097] The initial charge may also include one or more of the following components:

[0098] - a dispersant, at a rate of 0 to 10%, as a mass percentage based on the initial dry load;

[0099] - a surface tension modifier, at a rate of 0 to 3%, as a mass percentage based on the initial dry charge.

[0100] Dispersants and surface tension modifiers are well known to those skilled in the art.

[0101] Examples include,

[0102] - as dispersants, the family of sodium or ammonium polymethacrylates, the family of sodium or ammonium polyacrylates, the family of citrates, for example ammonium, the family of sodium phosphates, and the family of carbonic acid esters;

[0103] - as surface tension modifiers, organic solvents such as aliphatic alcohols.

[0104] If the shaping results from extrusion, thermoplastic polymers or thermosetting polymers may be added to the starting charge, said starting charge preferably not containing solvent.

[0105] In one embodiment, the process includes a step c) and steps a) and c) are carried out simultaneously, the process preferably not including a step b).

[0106] In step d), which is optional, any known conventional process for shaping adsorption media may be implemented.

[0107] Among these processes, we can mention:

[0108] - atomization processes,

[0109] - granulation processes, for example using granulators, fluidized bed granulators, or granulation discs,

[0110] - gelling processes,

[0111] - screen printing processes,

[0112] - injection molding processes, - extrusion processes, and

[0113] - pressing processes.

[0114] In one embodiment, the process according to the invention comprises steps b) and d), said steps b) and d) being carried out simultaneously, for example during atomization, steps a) and c) also being able to be carried out simultaneously, steps b) and d) being carried out simultaneously after steps a) and c), themselves carried out simultaneously.

[0115] In step e), optional, the product obtained at the end of the previous optional step d) is dried, for example in an oven.

[0116] In step f), the product obtained at the end of step a) if the process according to the invention does not include steps b), c), d), and e), or the product obtained at the end of b) if the process according to the invention includes such a step and does not include steps c), d), and e), or the product obtained at the end of c) if the process according to the invention includes such a step and does not include steps d) and e), or the product obtained at the end of d) if the process according to the invention includes such a step and does not include step e), or the product obtained at the end of step e), is heat-treated. Preferably, the heat treatment is carried out in air, preferably in an electric furnace, preferably at atmospheric pressure.

[0117] The heat treatment in step f) is carried out at a temperature preferably above 520°C, preferably above 540°C, preferably above 560°C, preferably above 570°C and preferably below 800°C, preferably below 750°C.

[0118] The holding time at the temperature plateau is preferably greater than 30 minutes, preferably greater than 1 hour and / or preferably less than 10 hours, preferably less than 7 hours, preferably less than 5 hours, preferably less than 3 hours. Preferably, the heat treatment time is between 1 and 3 hours.

[0119] The invention also relates to a product according to the invention obtained by the process according to the invention.

[0120] The invention also relates to a manufacturing process comprising the steps of the process as described in this application (i.e., step a); optionally, one or more of steps b) to e); and step f)) and further comprising an additional step g) consisting of at least partial protonation of the product obtained at the end of step f).

[0121] Protonation involves replacing at least part of the lithium Li + of the product according to the invention by protons H + in order to activate the product, that is, so that it can capture the lithium present in a liquid source.

[0122] This protonation is conventional and can be achieved, in particular, by bringing the product according to the invention into contact with an acidic liquid, preferably an acidic aqueous solution. All known acids can be used. Preferably, the acid used is chosen from sulfuric acid, hydrochloric acid, nitric acid, carboxylic acids, and mixtures thereof. Preferably, the acid used is sulfuric acid. The pH of the acidic solution is preferably greater than 1, and preferably less than 7, preferably less than 6, preferably less than 5, preferably less than 4, preferably less than 3, preferably less than 2.

[0123] The invention also relates to the product obtained at the end of said step g).

[0124] It is understood that the mass ratios (Mn+Fe) / Ti and Mn / (Mn+Fe) in the product obtained at the end of step g) are substantially identical to those of the product according to the invention. The specific and preferred mass ratios (Mn+Fe) / Ti and Mn / (Mn+Fe) described above for the product according to the invention therefore apply here to the product obtained at the end of step g).

[0125] EXAMPLES

[0126] The following non-limiting examples are given for the purpose of illustrating the invention.

[0127] Measurement protocol:

[0128] For each powder in the examples, the presence of iron and manganese in the Li2TiOs crystallized phase is demonstrated by X-ray diffraction, according to the following method.

[0129] The diffraction pattern was acquired using a Bruker D8 Endeavor instrument equipped with a copper anode, over an angular range of 5° to 100°, with a step size of 0.01° and a counting time of 0.34 s / step. The front optics consisted of a 0.3° primary slit and a 2.5° Soller slit. An automatic cutter was used. The rear optics consisted of a 2.5° Soller slit, a 0.0125 mm nickel filter, and a 1D detector with a 4° aperture.

[0130] Then, in the DIFFRAC.EVA version 6 software, marketed by the Bruker company, we import the ICSD29727 datasheet for the Li2TiOa phase and the diffraction diagram of the example to be analyzed.

[0131] Using the software's "Displacement" tool, the maximum intensity of the Li2TiOa phase peak located at approximately 18.5° in the example diffraction pattern is aligned with the theoretical value of said peak given in ICSD29727, located at approximately 18.46°. Then, the Li2TiOa phase peak in the example diffraction pattern is observed within an angular range of approximately 43.65°. Using the software's "Create Area" tool, then the "Select Area" function, a region containing the Li2TiOa phase peak in the example diffraction pattern, located at approximately 43.65°, is selected, ensuring that this region also includes a portion of the baseline and that it does not contain any other peaks.

[0132] Next, the value indicated in the "Obs. Max." box in the "Angle" section of the "Create Area" tool is noted. A "Obs. Max." value greater than 43.64°, the angular position of the peak of the Li2TiOa phase in datasheet ICSD29727, is considered to indicate the presence of iron and manganese in the Li2TiOa phase.

[0133] The average size of the crystallites of the doped Li2TiOs phase, D, of the powders of the examples is determined by X-ray diffraction on said powders using a D8 Endeavor type apparatus from the Bruker company according to the following method.

[0134] A diffraction pattern is obtained from a LaBe standard powder, NIST 660a reference, under the same conditions as for detecting the presence of iron and manganese in the Li₂TiO₂ phase, and then imported into DIFFRAC.EVA version 6 software. The "Create Area" tool is then used, followed by the "Select Area" function. A region containing the peak located at approximately 37.5° is selected, ensuring that this region also includes a portion of the baseline. The value displayed in the "FWHM" box within the "Angle" section of the "Create Area" tool is then recorded. This value is referred to as "Instr. Width" in the remainder of this description.

[0135] For each example, a diffraction pattern obtained under the same conditions as for demonstrating the presence of iron and manganese in the Li₂TiO₂ phase is imported into DIFFRAC.EVA version 6. The "Create Area" tool is then used, followed by the "Select Area" function. A region containing the peak of the doped Li₂TiO₂ phase at approximately 18.46° is selected, ensuring that this region also includes part of the baseline and that it does not contain any other peaks. "Use FWHM" is then selected, and a "K" value of 0.89 and the previously determined "Instr. Width" value are entered. The average size of the crystallites in the doped Li₂TiO₂ phase is taken to be equal to the "Crystallite size" value calculated by the software.

[0136] With the exception of element O, the contents of the different elements present in the products of the examples are determined, by inductively coupled plasma spectrometry (or "ICP" in English), after complete dissolution at 80°C under stirring, in an aqueous solution of sulfuric acid at 95% mass.

[0137] The magnetic properties of the examples are assessed using the following method, known as the "magnet method." A powder of the example product is placed on a support near a 0.1 T magnet, without the particles of said powder being attracted to the magnet. The particles are slowly moved closer to the magnet until they are attracted and adhere to it. The distance, in centimeters, between the position of the particles just before attraction by the magnet and the magnet is then recorded. The greater this distance, the stronger the magnetic properties of the example are considered to be.

[0138] The magnetic properties of the examples are also characterized by a magnetization measurement m(H), performed in DC mode, using a Squid magnetometer, model MPMS3-VSM, marketed by Quantum Design, at 298 K, with a field ramp-up along H 1 / 2 from 0 to 7 tesla (70,000 oe) at a rate of 100 oe / sec and 26 measurement points. The magnetization value is given at 7 tesla and expressed in emu / g.

[0139] Manufacturing protocol:

[0140] The following raw materials were used for the examples:

[0141] A lithium carbonate powder of purity greater than 99%, exhibiting a D50 of 9 pm,

[0142] A TiCh powder in the anatase form, with a purity greater than 99.2%, exhibiting a D50 of 0.3 pm,

[0143] A Fe2O3 powder, with a purity greater than 97%, exhibiting a D50 of 61 pm,

[0144] A MnsCL powder, of purity greater than 97%, exhibiting a D50 equal to 2 pm.

[0145] For each example, in step a), the quantities, in grams, of materials indicated in the following table 1 are introduced into a horizontal LME4 mill marketed by the Netzsch company, comprising for 85% of the volume of its chamber, Zirmil® Ce beads, of size 0.6 mm to 0.8 mm, marketed by the Saint-Gobain Zirpro company.

[0146] [Table 1] The mill is started and the lithium carbonate, TiCh, Fe2U3 and MnsCl powders are co-milled in a wet medium for 45 minutes. At the end of this co-milling, a wet particulate mixture is obtained with a 90th percentile of 0.9 pm.

[0147] 2000 g of this wet particulate mixture are taken. In step c), the viscosity of said wet particulate mixture is adjusted to a value equal to 4000 mPa.s by means of an addition of water and a viscosity regulator, so as to obtain a starting load, the viscosity being measured on a Brookfield RVD-II+ rotary viscometer using a movable spindle no. 5 at a rotational speed equal to 5 rpm.

[0148] The said starting charge is then shaped in a step d), into granules by atomization-drying in a Niro GEA Minor Mobile atomizer, in a hot air stream having an inlet temperature of 200°C and an outlet temperature of 120°C.

[0149] The formed granules are recovered and heat-treated in step f) at 700°C for examples 1 and 2, and at 600°C for examples 3 and 4, for a holding time of 2 hours, under air, with a temperature rise rate and a temperature fall rate of 100°C / h. At the end of step f), the granule powders of examples 1, 2, 3 and 4 have a Dso of 60 pm, 68 pm, 68 pm, and 65 pm, respectively.

[0150] The results obtained are shown in Table 2 below.

[0151] [Table 2]

[0152] (*) : outside invention

[0153] The products in examples 1 to 4 exhibit a high lithium adsorption capacity.

[0154] The products of examples 2 and 3 have a "Max. Obs." value determined as described above greater than 43.64°.

[0155] The products of Examples 2 and 3, according to the invention, have magnetic properties, assessed according to the magnet method described above, of 1.3 cm and 1.2 cm, respectively, the products of Examples 1 and 4, outside the invention, have magnetic properties, assessed according to the magnet method described above, of 1.1 cm and 0.8 cm, respectively.

[0156] The products of Examples 2 and 3, according to the invention, exhibit a magnetization, measured according to the method described above, of 16.7 emu / g and 23.7 emu / g, respectively, the products of Examples 1 and 4, outside the invention, exhibit a magnetization, measured according to the method described above, of 16.6 emu / g and 10.2 emu / g, respectively.

[0157] A comparison of Example 1 outside the scope of the invention and Example 3 according to the invention also shows the impact of the presence of manganese: for a mass ratio (Mn+Fe) / Ti substantially equal, the product of Example 3 heat-treated at 600°C has an average size of the crystallites of the doped Li2TiOs phase equal to 24.9 nm, less than that of Example 1 equal to 30.4 nm, magnetic properties assessed according to the magnet method described above equal to 1.2 cm whereas those of the product of Example 1 are equal to 1.1 cm, a magnetization measured according to the method described above equal to 23.7 emu / g whereas that of the product of Example 1 is equal to 16.6 emu / g, and a substantially equivalent lithium adsorption capacity. The presence of manganese in the products according to the invention therefore makes it possible to lower the heat treatment temperature without degrading the magnetic properties or the adsorption capacity of lithium.

[0158] A comparison of Example 4 (outside the scope of the invention) and Example 3 (according to the invention) also demonstrates the impact of the presence of manganese: for a substantially equal mass ratio (Mn+Fe) / Ti, the product of Example 3, heat-treated at 600°C, exhibits magnetic properties, assessed using the magnet method described above, of 1.2 cm, whereas those of the product of Example 4 (outside the scope of the invention), also heat-treated at 600°C, are 0.8 cm, a magnetization of 23.7 emu / g (compared to 10.2 emu / g for Example 4), and a higher lithium adsorption capacity. The presence of manganese in the products according to the invention therefore makes it possible to lower the heat treatment temperature without degrading the magnetic properties or the lithium adsorption capacity.

[0159] In a second series of examples, at step a), the quantities, in grams, of materials indicated in the following table 3 are introduced into a horizontal LME4 mill marketed by the Netzsch company, comprising for 85% of the volume of its chamber, Zirmil® Ce balls, of size 0.6 mm to 0.8 mm, marketed by the Saint-Gobain Zirpro company.

[0160] [Table 3]

[0161] The mill is started and the lithium carbonate, TiCh, Fe2U3 and MnsCl powders are co-milled in a wet medium for 45 minutes. At the end of this co-milling, a wet particulate mixture is obtained with a 90th percentile of 0.9 pm.

[0162] 2000 g of this wet particulate mixture are taken. In step c), the viscosity of said wet particulate mixture is adjusted to a value equal to 4000 mPa.s by means of an addition of water and a viscosity regulator, so as to obtain a starting load, the viscosity being measured on a Brookfield RVD-II+ rotary viscometer using a movable spindle no. 5 at a rotational speed equal to 5 rpm.

[0163] The said starting charge is then shaped in a step d), into granules by atomization-drying in a Niro GEA Minor Mobile atomizer, in a hot air stream having an inlet temperature of 200°C and an outlet temperature of 120°C.

[0164] The formed granules are collected and heat-treated in step f) at 700°C for a holding time of 2 hours, under air, with a temperature rise rate and a temperature fall rate of 100°C / h. At the end of step f), the granule powders of examples 5 and 6 have a Dso between 50 pm and 80 pm.

[0165] The results obtained are shown in Table 4 below.

[0166] [Table 4]

[0167] (*) : outside invention

[0168] The products in examples 5 and 6 exhibit a high lithium adsorption capacity.

[0169] The products in example 6 have a "Max. Obs." value determined as described above greater than 43.64°.

[0170] A comparison of Example 5 outside the scope of the invention and Example 6 according to the invention also demonstrates the impact of the presence of manganese: for a substantially equal mass ratio (Mn+Fe) / Ti, the product of Example 6 exhibits magnetic properties, assessed using the magnet method described above, of 1.2 cm, while those of the product of Example 5 are equal to 1.1 cm; a magnetization measured according to the method described above of 22.2 emu / g, while that of the product of Example 5 is equal to 14.4 emu / g; and a higher lithium adsorption capacity. Of course, the invention is not limited to the embodiments described, which are provided for illustrative purposes only.

Claims

DEMANDS 1. Product whose crystallized part comprises, preferably, essentially a Li2TiOa crystallized phase containing the elements Mn and Fe, said product comprising at least the elements Li, Ti, Fe, Mn and O, the elements Li, Ti, Fe, Mn being present in said product in the following amounts, determined by inductively coupled plasma spectrometry and in weight percentages: - 11% < Li < 15%, - 28% < Ti < 45%, - 0.1% < Mn < 12%, - 0.15% < Fe < 9%, the mass ratio (Mn+Fe) / Ti being such that: 0.03 < (Mn+Fe) / Ti < 0.

5.

2. Product according to the preceding claim having the following chemical analysis, determined by inductively coupled plasma spectrometry, in weight percentages: - 11% < Li < 15%, and - 28% < Ti < 45%, and - 0.1% < Mn < 12%, and - 0.15% < Fe < 9%, and Elements other than Li, Ti, Fe, Mn and O in a content less than 3%, and O in a content corresponding to the complement to 100%.

3. Product according to any one of the preceding claims, wherein: the Li content is greater than or equal to 11.5% and / or less than or equal to 13.5%, and / or the Ti content is greater than or equal to 33% and / or less than or equal to 41%, and / or the Mn content is greater than or equal to 1% and / or less than or equal to 8%, and / or the Fe content is greater than or equal to 1% and / or less than or equal to 8% and / or the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.18, and / or the sum of the Fe and Mn contents, Mn+Fe, is greater than 4.4%.

4. A product according to any one of the preceding claims, wherein: - the mass ratio Mn / (Mn+Fe) is greater than or equal to 0.15, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.18 and less than 0.24, and - the mass ratio Mn / (Mn+Fe) is greater than or equal to 0.4, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.24 and less than 0.36, and - the mass ratio Mn / (Mn+Fe) is greater than or equal to 0.7, when the mass ratio (Mn+Fe) / Ti is greater than or equal to 0.

36.

5. Product according to any one of the preceding claims, wherein all of the manganese present is in an oxidation state of +2. Product according to any one of claims 1 to 4, wherein all of the manganese present is in an oxidation state of +3. Product according to any one of claims 1 to 4, wherein all of the manganese present is in an oxidation state of +4. Product according to any one of claims 1 to 4, wherein all of the manganese present is partly in an oxidation state of +2 and partly in an oxidation state of +3.

9. Product according to any one of claims 1 to 4, wherein all of the manganese present is partly in an oxidation state of +2 and partly in an oxidation state of +4.

10. Product according to any one of claims 1 to 4, wherein all of the manganese present is partly in an oxidation state of +3 and partly in an oxidation state of +4.

11. Product according to any one of claims 1 to 4, wherein all of the manganese present is partly in an oxidation state +2, partly in an oxidation state +3 and partly in an oxidation state +4.

12. Product according to any one of the preceding claims, wherein the Li2TiC>3 crystallized phase comprising the elements Mn and Fe has an average crystallite size less than or equal to 90 nm.

13. A process for manufacturing a product according to any one of the preceding claims, comprising the following steps: a) preparation of a particulate mixture of raw material powders having a composition suitable to obtain, at the end of step f), a product according to any one of the preceding claims, b) optionally, drying of said particulate mixture, c) optionally, preparation of a starting charge from said particulate mixture, optionally dried, d) optionally, shaping of the starting charge, e) optionally, drying, f) heat treatment at a temperature above 500°C and below 850°C.

14. A method according to the preceding claim, in which - in step a), the particulate mixture has a 90th percentile less than 10 pm, and / or - in step a), the raw material powders are co-ground, and / or - in step f), the temperature is greater than 520°C and less than 800°C, and / or - at step f), the duration of holding at the temperature plateau is greater than 30 minutes and less than 10 hours.

15. A method according to the preceding claim, in which - in step a), the particulate mixture has a 90th percentile less than 2 pm, and / or - at step f), the temperature is greater than 540°C and less than 750°C.

16. A process according to any one of claims 13 to 15, wherein in step a), all of the manganese is supplied by MnO oxide.

17. A process according to any one of claims 13 to 15, wherein in step a), all of the manganese is supplied by the oxide Mn2C>3.

18. A process according to any one of claims 13 to 15, wherein in step a), all of the manganese is supplied by the oxide MnO2.

19. A process according to any one of claims 13 to 15, wherein in step a), all of the manganese is supplied by MnsC oxide 20. A process according to any one of claims 13 to 15, wherein in step a), all of the manganese is supplied by a mixture of the oxides MnO and Mn2C>3.

21. A process according to any one of claims 13 to 15, wherein in step a), all of the manganese is supplied by a mixture of the oxides MnO and MnO2.

22. A process according to any one of claims 13 to 15, wherein in step a), all of the manganese is supplied by a mixture of the oxides MnO, Mn2Os, MnsOt and MnO2.

23. A process according to any one of claims 13 to 15, wherein in step a), all of the manganese is supplied by a mixture of the oxides MnsOt and MnO2.

24. A process according to any one of claims 13 to 15, wherein in step a), substantially all of the manganese is supplied by a mixture of the oxides MnO, Mn2Oa and MnO2.

25. A process according to any one of claims 13 to 24, comprising an additional step g) consisting of at least partial protonation of the product obtained at the end of step f).

26. Product obtained by the process according to the preceding claim.

27. Lithium capture device, comprising a product according to any one of claims 1 to 12 or 26, or a product obtained by a process according to any one of claims 13 to 25.

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