EP2734481A1

EP2734481A1 - Method for producing a molten material

Info

Publication number: EP2734481A1
Application number: EP12758618.8A
Authority: EP
Inventors: Caroline Levy; Arnaud APHECEIXBORDE
Original assignee: Saint Gobain Centre de Recherche et dEtudes Europeen SAS
Current assignee: Saint Gobain Centre de Recherche et dEtudes Europeen SAS
Priority date: 2011-07-21
Filing date: 2012-07-16
Publication date: 2014-05-28
Also published as: US20140158933A1; JP2014524883A; JP6049713B2; CN103813992A; KR20140046024A; WO2013011452A1; US9620778B2; FR2978137A1; CN103813992B

Abstract

The present invention relates to a method for manufacturing a molten material, the crystallised portion of which consists, for more than 99.3 wt %, of a single crystalline phase having the formula (Li₁-_aA_a)_1+x(G₁-_bJ_b) _y[(XO₄)₁-_dD_d]_zE_e, where: Li is the element lithium; A is a lithium substituent selected from among the elements Na, K, H, and the mixtures thereof, wherein a is no higher than 0.2; G is selected from among the elements Fe, Mn, Ni, Co, V, and the mixtures thereof; J is a substituent of G selected from among Nb, Y, Mg, B, Ti, Cu, Cr and the mixtures thereof, wherein b is no higher than 0.5; XO₄ is an oxyanion in which O designates the element oxygen and X is selected from among the elements P, S, V, Si, Nb, Mo, Al, and the mixtures thereof; D is selected from among the anions F-, OH-, C^I-, and the mixtures thereof, wherein d is no higher than 0.35; E being selected from among the element F, the element Cl, the element O, the OH group, or the mixtures thereof; 0 ≤ e ≤ 2; -0.2 ≤ x ≤ 2; 0.9 ≤ y ≤ 2; and 1 ≤ z ≤ 3, said method including the following steps: a) mixing raw materials so as to form a feedstock; b) melting the feedstock until a liquid mass at a temperature Tm, which is higher than the melting temperature Tf of the molten material obtained at the end of step e), is obtained; c) cooling until said liquid mass is completely solidified, so as to obtain a molten material, the amorphous phase of which is constitutes less than 80 wt % thereof; d) optionally crushing and/or grinding and/or performing selection by particle size on said molten material; e) optionally, heat-treating the molten material at a temperature which is an increment lower than the melting temperature Tf of said molten material and which is between Tf-800°C (or 500°C if Tf-800°C is less than 500°C) and Tf-50°C, for a period of time during which the temperature is maintained at said increment and which is more than 90 minutes, in a reducing environment; and f) optionally, crushing and/or grinding and/or performing selection by particle size on said molten material.

Description

PROCESS FOR PRODUCING A MOLTEN PRODUCT

Technical area

The invention relates to a molten product based on lithium, a process for producing such a product. This product may in particular be used as electrode material, in particular in a lithium-ion battery.

The invention also relates to such a battery. State of the art

A family of crystallized phases of formula

(Li _1-a A _a ) _{1 + x} (G ₁ -b J _b ) _y [(XO ₄ ) i -dDd] zEe, wherein:

Li is the lithium element,

A is a lithium substituent selected from the elements Na, K, H and mixtures thereof, a being less than or equal to 0.2 (substitution ratio less than or equal to 20 atomic%),

G is selected from Fe, Mn, Ni, Co, V and mixtures thereof,

- J is a substituent of G selected from Nb, Y, Mg, B, Ti, Cu, Cr and mixtures thereof, b being less than or equal to 0.5 (substitution rate less than or equal to 50 atomic%),

X0 ₄ is an oxoanion in which O denotes the oxygen element and X is selected from P, S, V, Si, Nb, Mo, Al and mixtures thereof,

- D is chosen from F ^" , OH ^" , CI ^" anions and their mixtures, d being less than or equal to 0.35 (substitution rate less than or equal to 35 at%), d being zero,

E is chosen from the element F, the element Cl, the element O, the group OH, and their mixtures,

- 0 <e <2,

- -0.2 <x <2,

- 0.9 <y <2,

- 1 <z <3.

Among the phase-rich products (Li ₁ -a A _a ) _{1 + x} (Gi-bJb) y [(XO ₄ ) i-dD _d ] _z E _e , the products obtained by solid-phase sintering or by sweet chemistry and melted products.

The products obtained by solid phase sintering or by soft chemistry may have a very high percentage of phases (Li ₁ -a A _a ) _{1 + x} (Gi-bJb) y [(X0 ₄ ) i-dD _d ] _z E _e on all crystallized phases. But these products are much more expensive to manufacture than molten products.

Molten products are for example described in WO2005 / 062404 or in the article "Melt casting LiFePO ₄ ", Journal of the electrochemical Society, 157 (4) A453-A462 (2010), M. Gauthier and Al. sintered products, the melted products can be manufactured industrially, at low costs, but are less rich in phases (Li _1-a A _a ) _{1 + x} (G _{1 -b} J _b ) _y [(X0 ₄ ) i _{- d} D _d ] _z E _e .

Molten products can be made by rapidly cooling a mass of molten liquid so as to create a predominantly amorphous structure, followed by crystallization heat treatment. This gives a glass ceramic. Such methods are in particular described in EP 2 295 385, WO 201 1/049034 or WO 2010/1 14104. The article "Lithium ion conductive glass-ceramics semi-mix with Li ₃ Fe 2 (PO ₄ ) ₃ and YAG laser- By Nagamine et al., Solid States lonics 179 (2008) 508-515 describes the possibility of drawing crystal patterns by means of laser technology.

According to these methods, quenching typically leads to a product consisting of more than 90% by mass of amorphous phase.

In addition, lithium is a natural fondant, which sublimates if the melting temperature is too high. In order to manufacture these melted products, the melting temperature is therefore conventionally determined to be as close as possible to the melting temperature of the raw materials of the feedstock.

Lithium-ion batteries, manufactured in large quantities, can incorporate phase-rich products (Li _1-a A _a ) _{1 + x} (G ₁ -b Jb) y [(X0 ₄ ) i-dD _d ] _z Ee, especially for the manufacture of their cathodes. Their performances as well as their lifetimes are dependent, among other things, on the phase richness (Li _1-a A _a ) _{1 + x} (Gi-bJb) y [(X0 ₄ ) i-dD _d ] _z E _e of product used.

There is therefore a need for a phase-rich product (Li _1- aA _a ) _{1 + x} (Gi-bJb) y [(XO ₄ ) i-dD _d ] _z E _e , adapted as electrode material and capable of be manufactured in industrial quantities and at a reduced cost.

An object of the invention is to satisfy, at least partially, this need. Summary of the invention

According to the invention, this object is achieved by means of a product whose crystallized part consists, for more than 99.3% by mass, of the same phase (Li _1-a A _a ) _{1 + x} (G _1-b Jb) y [(X04) i-dDd] zEe, called "LAGJXODE phase" (for the sake of clarity). This product is remarkable in that it is melted, that is to say that it is obtained by melting then solidification.

Although the manufacture of molten products comprising a LAGJXODE phase is well known, it is the merit of the inventors to have discovered a process which, surprisingly, makes it possible to produce a very rich melted product in the LAGJXODE phase, as will be seen in more detail in the following description.

Advantageously, a product according to the invention can therefore be manufactured at reduced costs and in industrial quantities.

By "same phase (Li _1-a A _a ) _{1 + x} (G ₁ -bJb) y [(XO 4) i -dDd] zE _e " or "phase LAGJXODE" is meant a crystallized phase of formula (Li _1-a A _a ) _{1 + x} (Gi-bJb) y [(X04) i-dDd] zE _e determined, with a, b, d, e, x, y, z, A, G, J, X, D and E set. Thus, for example, a product having 90% of a first phase (Li _1-a A _a ) _{1 + x} (G ₁ -bJb) y [(XO 4) i -dDd] zE _e , with a = a 1, b = bi, d = di, e = βι, x = Xi, y = yi, z = z ₁ , A = A ₁ , G = Gi, J = Ji, X = Xi, D = Di and E = E ^ and 9 , 5% of a second phase (Li _1-a A _a ) _{1 + x} (Gi _-b Jb) y [(X04) i-dDd] zEe, where a = a ₂ , b = b ₂ , d = d ₂ , e = e ₂ , x = x ₂ , y = y ₂ , z = z ₂ , A = A ₂ , G = G ₂ , J = J ₂ , X = X ₂ , D = D ₂ and E = E ₂ , such that ai ≠ a ₂ and / or b1 ≠ b ₂ and / or di ≠ d ₂ and / or e1 ≠ e ₂ and / or Xi ≠ x ₂ and / or yi ≠ y ₂ and / or ≠ z ₂ and / or A- _\ ≠ A ₂ and / or d ≠ G ₂ and / or Ji ≠ J ₂ and / or Xi ≠ X ₂ and / or D- _\ ≠ D ₂ and / or Ei ≠ E ₂ , is not according to the present invention.

Preferably, a product according to the invention also comprises one, and preferably several, of the following optional characteristics:

at <0.15, preferably at <0.1, preferably at <0.05. In one embodiment, a = 0 (no substitution of lithium);

in particular when A is the hydrogen element H, preferably at> 0.05;

G is selected from Fe, Co, Mn, V and mixtures thereof, preferably from Fe, Co, Mn and mixtures thereof;

- G is Fe;

b <0.40, preferably b <0.35, preferably b <0.30, preferably b <0.25, or even b <0.20, or even b <0.15; in one embodiment, b> 0.05, or even b> 0.1;

the substituent element J is selected from Nb, Y, Mg, B, Ti and mixtures thereof; X is selected from P, S, Si and mixtures thereof;

preferably, X is the element P;

d <0.30, or even d <0.25, or even d <0.20, or even d <0.15, or even d <0.10, or even d <0.05. In one embodiment, d = 0;

- D is F;

E is the element F (fluorine);

x≥ -0, 1, preferably x≥ -0.05, or even x≥0 and / or x <1.5, preferably x <1, 3, preferably x <1, 2, preferably x <1 ;

in one embodiment, x = 0;

in one embodiment, y = 2;

in one embodiment, y <1, 5;

in one embodiment, y = 1;

in one embodiment, y≥ 1;

in one embodiment, e = 2;

in one embodiment, e <1, 5, or even e <1;

in one embodiment e = 1;

In one embodiment e = 0;

in one embodiment z = 1;

the crystallized part consists, for more than 99.5%, preferably more than 99.7%, preferably more than 99.8%, preferably more than 99.9%, preferably substantially 100% by weight, of said phase LAGJXODE,

- the LAGJXODE phase is LiFeP0 _4, or Li ₃ V ₂ (P04) _3, or LiMnP0 _4, or Li ₂ FeSi0 ₄ or LiVP0 ₄ F, or LiCoP0 ₄ or LiMn _0, _{8Feo, 2} P0 ₄ or LiFe ₀ , 33Mn ₀ , 67PO ₄ , or LiFePO ₄ F, or LiFeSO ₄ F, or Li ₂ CoPO ₄ F, or LiVPO ₄ ;

- The product is an annealed product, that is to say, having undergone a heat treatment after solidification;

preferably, the product is not coated with a carbon layer; In one embodiment, the product is in the form of a particle powder and more than 50%, preferably more than 70%, preferably more than 90%, preferably more than 95%, preferably more than %, preferably substantially 100% by number, the particles are not covered, even partially, carbon; the product is polycrystalline; the mass quantity of the amorphous phase is less than 80%, less than 70%, less than 60%, less than 50%, less than 40%, less than 30%, less than 20%, less than 10%, less than 5%, less than 3%, less than 2%, or less than 1%, based on the mass of the molten product;

the amount of LAGJXODE phases in which the iron has a valence greater than or equal to 3, and in particular in the Li ₃ Fe 2 (PO ₄ ) 3 phase, is less than

30%, preferably less than 20%, preferably less than 10%, preferably less than 5%, preferably less than 1%, by mass percentage.

Advantageously, these optional characteristics improve the electrochemical performances, making the products particularly well adapted, after possible grinding, to the manufacture of cathodes for lithium-ion batteries.

A product according to the invention may be in the form of a block of which all the dimensions are preferably greater than 1 mm, preferably greater than 2 mm, preferably greater than 1 cm, preferably greater than 5 cm, preferably even greater than 15 cm. Preferably, a block according to the invention has a mass greater than 200 g.

The invention also relates to a powder of a melted product according to the invention. The median size of the powder is preferably greater than 0.05 μηη and / or less than 100 μηη.

In a particular embodiment, the median size of the powder is between 0.05 μm and 5 μm, preferably between 0.05 μm and 2 μm, preferably between 0.05 μm and 0.2 μm. In a particular embodiment, the median size of the powder is between 5 μηη and 20 μηη, preferably between 7 μηη and 15 μηη.

More than 50%, preferably more than 70%, preferably more than 90%, preferably more than 95%, preferably more than 99%, preferably substantially 100% by number, of the particles may be at least partially covered, preferably all of carbon or a precursor of carbon.

Process

The invention also relates to a first process for manufacturing a melted product according to the invention, comprising the following steps:

a) mixing of raw materials so as to form a feedstock, b) melting of the feedstock to obtain a liquid mass at a temperature T _m i greater than the melting temperature T _f of the molten product obtained at the end of step e) (which may be greater than the temperature strictly necessary for the melting of the feedstock),

c) cooling until complete solidification of said liquid mass, so as to obtain a molten product, d) optionally, crushing and / or grinding and / or granulometric selection of said melted product,

e) heat treatment of the molten product at a plateau temperature lower than the melting temperature T _{f of} said melted product and between T _f - 800 ° C, or 500 ° C if T _f - 800 ° C is lower than 500 ° C , and T _f - 50 ° C, during a hold time greater than 90 minutes, and in a reducing environment,

f) optionally, crushing and / or grinding and / or granulometric selection of said melted product,

the raw materials in step a) and, optionally, the gaseous environment in step b) being determined so that the crystallized portion of said melted product has, for more than 99.3% by weight, the same phase ( Li _1- aA _a ) _{1 + x} (G ₁ -b Jb) y [(XO 4) i -dDd] zEe as defined above.

Preferably, and remarkably, in step b), the melting takes place in a neutral environment or containing oxygen, preferably in air. The conduct of the melting process is facilitated.

Preferably, in step c), the cooling rate until complete solidification of the liquid mass is less than 1000 K / s, or even less than 800 K / s, or even less than 500 K / s.

The invention also relates to a second process for manufacturing a melted product according to the invention, the crystallized part of which has, for more than 99.3% by weight, the same phase (Li _1-a A _a ) _{1 + x} (Fei-bJb) y [(PO ₄ ) i -dDd] z, said process comprising the following steps:

a ') mixing raw materials to form a feedstock, b') melting the feedstock to a liquid mass at a temperature T _m i above the melting temperature T _f of the product melted at the end of step c '), the temperature T _m i being such that:

o if the element Fe is provided for more than 97% of its mass by FePO ₄ , nH ₂ O with 0 <n <6, then T _m i is greater than 1250 ° C, and preferably less than 1350 ° C, or

o if the element Fe is brought for more than 3% of its mass by Fe ₂ 0 ₃ , then

T _m i is greater than 1350 ° C, and preferably less than 1550 ° C, or o if the Fe element is provided for more than 5% of its mass by Fe ₃ 0 ₄ , then

T _m i is greater than 1350 ° C, and preferably less than 1550 ° C, or o if the Fe element is provided for more than 97% of its mass by FeO, then T _m i is preferably less than 1 100 ° C, or o if the element Fe is provided for more than 97% of its mass by a mixture of FeO and FePO ₄ , nH ₂ 0 with 0 <n <6, said mixture comprising more than 3% and less than 97% of FePO ₄ , nH ₂ 0 with 0 <n <6, then T _m i is greater than 1250 ° C, and preferably less than 1350 ° C, c ') cooling until complete solidification of said liquid mass, so as to obtain a melted product according to the invention,

d ') optionally, grinding and / or granulometric selection of said melted product so as to obtain a powder of said melted product,

the raw materials in step a ') and, optionally, the gaseous environment in step b') being determined so that the crystallized portion of said melted product has, for more than 99.3% by weight, (Li _1-a A _a ) _{1 + x} (Fe ₁ -bJb) y [(PO ₄ ) i-dDd] z. Advantageously, this second manufacturing method makes it possible to produce a molten product comprising less than 30%, preferably less than 20%, preferably less than 10%, preferably less than 5%, preferably less than 1%, of phases (Li _1-a A _a ) _{1 + x} (Fe ₁ .bJb) y [(0 ₄ ) i -DDD] _z in which iron has a valence greater than or equal to 3, and especially a small amount of Li ₃ Fe ₂ (P0 ₄₎ _3. Advantageously, a low phase content in which the iron has a valence greater than or equal to 3 improves the electrochemical performance of the battery comprising the melted product according to the invention.

Preferably and remarkably, in step b '), the melting takes place in a neutral environment or containing oxygen, preferably in air. The conduct of the melting process is facilitated.

This second process is also remarkable in the sense that it makes it possible to obtain a melted product (Li _1-a A _a ) _{1 + x} (Fe ₁ -bJb) y [(PO ₄ ) i -dDd] z according to US Pat. invention without a heat treatment step after the melting step (unlike the first manufacturing method according to the invention which comprises a step e)).

In one embodiment, in step a) or step a '), the raw materials may be in the solid state and / or liquid, preferably solid.

In one embodiment, one or more raw materials may be provided in the form of a gas, in particular to provide the chlorine element C1 or the fluorine element F, during step b) or b ').

The methods of the invention can be used for the manufacture of particles or blocks. They can be adapted so that the melted product has one or more of the optional features mentioned above. The invention also relates to a product manufactured or likely to have been manufactured by a process according to the invention.

The invention also relates to the use of a molten product according to the invention or manufactured or likely to have been manufactured by a method according to the invention in the manufacture of a cathode for lithium-ion battery.

The invention finally relates to a cathode for a lithium-ion battery comprising a melted product according to the invention or manufactured or likely to have been manufactured by a method according to the invention, and a lithium-ion battery comprising such a cathode. The cathode may in particular be obtained by shaping a powder according to the invention. Brief description of the figures

Other objects, aspects, properties and advantages of the present invention will become apparent in the light of the description and examples which follow and on examining the appended drawing in which FIG. 1 represents, in cross section, a portion of a battery according to the invention. Definitions

- The "LAGJXODE phase rate" is the percentage of LAGJXODE phase on all the crystallized phases of the product, this set being called "crystallized part".

For a LAGJXODE phase considered, an International Center for Diffraction Data (ICDD) sheet is used to identify the angular domains of the diffraction peaks corresponding to said LAGJXODE. For example, ICDD record 40-1499 is that of the olivine phase LiFePO _4.

The LAGJXODE phase rate can be evaluated by the following formula (1):

T - 1 00 * (ALAGJXODE) / (ALAGJXODE ⁺ Secondary Aphases) (1) or

ALAGJXODE is the area of the non-superimposed higher intensity diffraction peak or its non-superimposed higher intensity diffraction multiplet, of the LAGJXODE phase, measured on an X-ray diffraction pattern of said product, for example obtained from a device of the D5000 diffractometer type from the company BRU KER provided with a copper DX tube. The acquisition of the diffraction pattern is carried out from this equipment, on an angular range 2Θ of between 5 ° and 80 °, with a pitch of 0.02 °, and a counting time of 1 s / step. The sample is rotating on itself in order to limit the orientations preferred. The processing of the diagram obtained can be achieved for example using the EVA software, without deconvolution treatment;

- Secondary Aphases is the sum of the areas of the secondary phases, measured on the same diagram, without deconvolution treatment. The area of a secondary phase is that of its diffraction peak of higher non-superimposed intensity or diffraction multiplet of higher non-superimposed intensity. The secondary phases are the phases detectable by X-ray diffraction other than the LAGJXODE phase. Among others, Fe ₂ 0 ₃ , FePO ₄ , Li ₃ PO ₄ , AIPO ₄ or Li ₃ Fe ₂ (PO ₄ ) ₃ may be secondary phases identified on the X-ray diffraction diagram, in particular when the LAGJXODE is LiFePO ₄ . A "non-superimposed" diffraction peak is a diffraction peak corresponding to a single phase (no overlap of two peaks corresponding to two different phases). Similarly, a diffraction multiplet "not superimposed" is a diffraction byte corresponding to a single phase.

The precision of such a measurement is equal to 0.3% in absolute.

A product is conventionally said to be "melted" when it is obtained by a process implementing a melting of raw materials until a liquid mass is obtained (which may contain solid particles, but in an insufficient quantity to structure said liquid mass, so that it must be contained in a container to keep its shape), then solidification by cooling.

"Particle" means a solid object whose size is less than 10 mm, preferably between 0.01 μηη and 5 mm.

By "size" of a particle is meant the diameter of the sphere of the same volume. The particle size of a powder is evaluated classically by a particle size distribution characterization performed with a laser granulometer. The laser granulometer may be, for example, a Partica LA-950 from the company HORIBA.

The percentiles or "percentiles" 50 (D ₅₀ ) and 99.5 (D ₉₉ , ₅ ) are the particle sizes corresponding to the percentages by mass of 50% and 99.5%, respectively, on the cumulative particle size distribution curve. particle sizes of the powder, the particle sizes being ranked in ascending order. For example, 99.5% by weight of the powder particles are smaller than _99.5 % and 0.5% of the bulk particles are larger than _99.5% . Percentiles can be determined using a particle size distribution using a laser granulometer.

The "maximum size of a powder" is the 99.5 percentile (D _99.5 ) of said powder. The "50th percentile" (D ₅₀ ) of said powder is called the "median size of a powder". By "block" is meant a solid object that is not a particle. "Impurities" means the inevitable constituents introduced involuntarily and necessarily with the raw materials or resulting from reactions with these constituents. Impurities are not necessary constituents, but only tolerated. For example, the compounds forming part of the group of oxides, nitrides, oxynitrides, carbides, oxycarbides, carbonitrides and metallic species of sodium and other alkalis, chromium, yttrium, magnesium, boron, copper, and niobium are impurities if their presence does not occur. is not desired, that is to say that they do not enter into the composition of the LAGJXODE product to be manufactured.

- A "carbon precursor" is a compound which, by heat treatment, in particular by pyrolysis, is converted, at least in part, into carbon. An organic polymer, such as polyethylene glycol or PEG, is an example of a carbon precursor.

- Unless otherwise indicated, all grades are percentages by mass.

- "containing one", "comprising one" or "comprising one" means "containing at least one", unless otherwise indicated.

detailed description

An example of the first method according to the invention is now described in detail.

In step a), a feedstock for producing a molten product according to the invention is formed from the lithium, A, G, J, D, X and E components, or compounds of these constituents, in particular compounds of oxides and / or carbonates and / or hydroxides and / or oxalates and / or nitrates and / or phosphates and / or metals and / or chlorides and / or fluorides and / or sulphides and / or ammonia compounds. Preferably, these compounds are chosen from phosphates, carbonates and oxides. These compounds may be chosen preferably from Li ₂ O, Li ₂ CO ₃ , LiOH, LiH ₂ PO ₄ , Li ₃ PO ₄ , LiF, Na ₂ CO ₃ , NaOH, KOH, Fe, Fe ₂ O ₃ , Fe ₃ O ₄ , FeO, FePO ₄ , nH ₂ O with O <n <6, Co ₃ O ₄ , CoO, V ₂ O ₅ , Nb ₂ O ₅ , Y ₂ O ₃ , B ₂ O ₃ , TiO ₂ , Cu ₂ O , CuO, Cr ₂ O ₃ , NH ₄ H ₂ PO ₄ , (NH ₄ ) ₂ HPO ₄ , H ₃ PO ₄ , P ₂ O ₅ , SiO ₂ , Al ₂ O ₃ , MoO, MnO, Mn ₂ O ₃ , MnO ₂ , Mn ₃ O ₄ , MgO, MgCO ₃ , NiO. Preferably, these compounds are chosen from Li ₂ O, Li ₂ CO ₃ , Li ₃ PO ₄ , Na ₂ CO ₃ , Fe ₂ O ₃ , Fe ₃ O ₄ , FeO, FePO ₄ , nH ₂ O with 0 <n < 6, Co ₃ O ₄ , CoO, V ₂ O ₅ , Nb ₂ O ₅ , Y ₂ O ₃ , B ₂ O ₃ , TiO ₂ , Cu ₂ O, CuO, Cr ₂ O ₃ , NH ₄ H ₂ PO ₄ , (NH ₄ ) ₂ HPO ₄ , H ₃ PO ₄ , P ₂ O ₅ , SiO ₂ , Al ₂ O ₃ , MoO, MnO, Mn ₂ O ₃ , MnO ₂ , Mn ₃ O ₄ , MgO, MgCO ₃ , NiO.

In one embodiment, the element F is provided in the form of a gas.

In one embodiment, the element C1 is provided in the form of a gas. Preferably, the compounds of the lithium, A, G, J, D, X and E components together represent more than 90%, more than 95%, more than 98%, preferably more than 99%, in percentages by weight, of the constituents the starting charge. Preferably these compounds together with the impurities represent 100% of the constituents of the feedstock.

Preferably, no compound other than those providing the lithium components, A, G, J, D, X and E is intentionally introduced into the feedstock, the other constituents present thus being impurities.

The lithium components A, G, J, D, X and E of the feedstock are found essentially in the melt produced. Some of these constituents, for example manganese and / or lithium, vary depending on the melting conditions, but can volatilize during the melting step. Those skilled in the art know how to adapt the composition of the feedstock accordingly so as to obtain, after step e), a molten product according to the invention.

In one embodiment, the feedstock comprises less than 10%, less than 5%, less than 1%, or no oxide (s) of silicon and / or aluminum and / or niobium and / or boron and / or germanium and / or gallium and / or antimony and / or bismuth. These elements may, however, be present in the feedstock in a form other than an oxide.

The granulometries of the powders used can be those commonly encountered in the melting processes.

Intimate mixing of the raw materials can be done in a mixer. This mixture is then poured into a melting furnace.

In step b), the feedstock is melted until a liquid mass is obtained, at a temperature T _m i greater than the melting temperature T _f of the molten product obtained at the end of the feed. step e), preferably in an electric arc furnace. Electrofusion makes it possible to manufacture large quantities of melted product with interesting yields.

One can for example use a Herault type arc furnace comprising two electrodes and whose vessel has a diameter of about 0.8 m and can contain about 180 kg of molten liquid.

But all known furnaces are possible, such as an induction furnace, a plasma furnace or other types of oven Herault, provided they allow to completely melt the starting charge. In particular for a molten LiFePO ₄ product, an energy of between 400 and 1200 kWh / T is well suited.

It is also possible to carry out melting in a crucible in a heat treatment furnace, preferably in an electric furnace, preferably in a neutral or reducing environment.

Preferably, an arc furnace or an induction furnace is used.

Without this being systematic, it is possible to increase the quality of stirring by bubbling a neutral gas as mentioned in FR 1 208 577. The stirring quality of the molten liquid can in particular be improved by sparging with nitrogen. The flow rate and / or the temperature of said gas is preferably adapted so that the temperature of the liquid mass is not substantially affected by this addition of gas.

The inventors have found that, surprisingly, in the first method according to the invention, the environment during the melting step b) has little influence on the melted product obtained at the end of step e). It is therefore possible to perform the melting step b) in a neutral or oxidizing environment, preferably in air. The conduct of the process is advantageously simplified.

Preferably, when G is not the element Fe, it is heated so that the temperature of the molten liquid mass T _m i is less than T _f + 300 ° C, preferably less than T _f + 150 ° C, and / or greater than T _f + 20 ° C, preferably greater than T _f + 50 ° C.

At the end of step b), the feedstock is in the form of a liquid mass, which may optionally contain some solid particles, but in an amount insufficient for them to structure said mass. By definition, to maintain its shape, a liquid mass must be contained in a container.

In a first embodiment, step c) comprises the following operations:

Ci) dispersion of the liquid mass in the form of liquid droplets,

c ₂ ) solidification of these liquid droplets by contact with a fluid, preferably an oxygenated fluid, preferably in air, so as to obtain molten particles. By simple adaptation of the composition of the feedstock, conventional dispersion processes, in particular by blowing or atomization, thus make it possible to manufacture, from a molten liquid mass, particles of different sizes into a melted product. the invention. In operation Ci), a stream of molten liquid is dispersed in liquid droplets. The dispersion can result from blowing through the net of the liquid mass. But any other method of atomizing a liquid mass, known to those skilled in the art, is possible.

In operation Ci), said liquid mass is brought into contact with a fluid, preferably a neutral fluid or an oxygenated fluid, preferably an oxygenated fluid, preferably a fluid comprising at least 20% by volume of oxygen, preferably gaseous, more preferably with air.

In operation c ₂ ), the liquid droplets are converted into solid particles by contact with a fluid, preferably a neutral fluid or an oxygenated fluid, preferably an oxygenated fluid, preferably a fluid comprising at least 20% by volume of water. oxygen, preferably gaseous, more preferably with air.

Preferably, the fluid used is the same for the two operations Ci) and c ₂ ).

Preferably, the process is adapted so that, as soon as formed, the molten liquid droplet is in contact with the fluid. More preferably, the dispersion (operation Ci)) and the solidification (operation c ₂ )) are substantially simultaneous, the liquid mass being dispersed by a fluid, preferably gaseous, able to cool and solidify this liquid.

Preferably, the contact with the fluid is maintained at least until complete solidification of the droplets.

Air blowing at room temperature is possible.

At the end of the operation c ₂ ), solid particles are obtained which have a size of between 0.01 μηη and 5 mm, or even between 0.01 μηη and 3 mm, depending on the dispersion conditions.

The melted product according to the invention may be at the end of step c ₂ ) in the form of particles smaller than 50 μηη. The grinding of said particles can then, for the manufacture of a cathode, be optional.

In a second embodiment, step c) comprises the following operations: Ci ') pouring the liquid mass into a mold;

c ₂ ') cooling solidification of the liquid mass cast in the mold until a block at least partially solidified;

c ₃ ') demolding the block. In operation ci '), the liquid mass is poured into a mold capable of withstanding the molten liquid mass. Preferably, graphite, cast iron, or as defined in US 3,993.1 19 molds are used. In the case of an induction furnace, the turn is considered to constitute a mold. Casting is preferably carried out under air.

In step c ₂ '), the liquid mass cast in the mold is cooled until an at least partially solidified block is obtained.

The cooling rate of the molten liquid during solidification is always less than 1000 K / s, or even less than 500 K / s, or even less than 100 K / s.

In one embodiment, during solidification, the liquid mass is brought into contact with a neutral fluid or an oxygenated fluid, preferably an oxygenated fluid, preferably a fluid comprising at least 20% by volume of oxygen, preferably gaseous, more preferably with air. In general, said liquid mass and / or the block can be brought into contact with said oxygenated fluid in the operation ci ') and / or in the operation c ₂ ') and / or in the operation c ₃ ') and / or after the operation c ₃ ').

This contacting can therefore be performed as soon as the casting. However, it is preferable to start this contacting only after casting. For practical reasons, the contact with the fluid preferably begins after demolding.

In step c ₃ '), the block is demolded.

In step d), optional, the melted product, in the form of particles or blocks, is crushed and / or crushed. All types of crushers and crushers are usable. Preferably, an air jet mill or a ball mill is used.

In one embodiment, the method comprises a step d).

The molten product is preferably ground so as to obtain a powder having a maximum size D _{99.5 of} less than 100 μηη, preferably less than 80 μηη, preferably less than 50 μηη, preferably less than 30 μηη, preferably less than at 10 μηη, preferably less than 5 μηη, preferably less than 1 μηη.

The melted product, optionally after grinding, preferably undergoes a granulometric selection operation depending on the intended applications, for example by sieving.

Whatever the embodiment considered, impurities from the raw materials may be present. In particular, the elements Ba, Sr, Yb, Ce, Ca can be found as impurities; and Si, S, Na, K, Nb, Y, B, Ti, Cu, Cr, Mg, Al when it is not desired for the LAGJXODE phase to contain these elements.

Preferably, the total mass content of impurities is less than 2%, preferably less than 1%, preferably less than 0.7%. Preferably again,

- Ca <0.2%, preferably Ca <0.1%, and / or

Al <0.5%, preferably Al <0.3%, preferably <0.2%, if X0 ₄ does not contain aluminum, and / or

- If <0.2%, preferably Si <0.15%, if X0 ₄ does not contain silicon, and / or - Na <0.8%, preferably Na <0.6%, preferably Na < 0.5%, preferably Na <0.4%, if A does not contain sodium, and / or

Ti <0.2%, preferably Ti <0.1%, if G does not contain titanium.

In step e), the melted product undergoes a crystallization heat treatment, which advantageously makes it possible to reduce the amount of amorphous phase and to increase the amount of LAGJXODE phase.

In step e), preferably the temperature of the heat treatment is greater than T _f - 700 ° C, preferably greater than T _f - 600 ° C, preferably greater than T _f - 530 ° C, preferably greater than T _f - 480 ° C, preferably greater than T _f - 430 ° C, preferably greater than T _f - 380 ° C, preferably greater than T _f - 330 ° C, and / or preferably less than T _f - 80 ° C, preferably less than T _f - 130 ° C, preferably less than T _f - 180 ° C, preferably less than T _f - 230 ° C. For example, for a molten LiFePO ₄ product, the temperature of the heat treatment is greater than 500 ° C., preferably greater than 550 ° C., preferably greater than 600 ° C., preferably greater than 650 ° C., and less than 930 ° C. ° C, preferably below 900 ° C, preferably below 850 ° C, preferably below 800 ° C, preferably below 750 ° C.

Preferably, the dwell time is greater than 2 hours and / or less than 24 hours, preferably less than 15 hours, preferably less than 10 hours. A bearing temperature of 700 ° C, maintained for 5 hours is well suited.

The reducing environment can be created by flushing a gas such as a CO / CO ₂ mixture or an N ₂ / H ₂ mixture. But any method for generating a reducing environment known from the state of the art can be used.

Preferably, the particles are annealed in a reducing environment created by a gas. In step f), optional, the annealed melted particles can be crushed and / or undergo a granulometric selection operation depending on the intended applications, for example by sieving, in particular so that the particles obtained constitute a powder having a size median greater than 0.05 μηη and / or less than 100 μηη. In a particular embodiment, the median size of the powder is between 0.05 μm and 5 μm, preferably between 0.05 μm and 2 μm, preferably between 0.05 μm and 0.2 μm. In a particular embodiment, the median size of the powder is between 5 μηη and 20 μηη, preferably between 7 μηη and 15 μηη.

In a subsequent step, more than 50% by number of the particles of the melted product of the powder obtained at the end of step e) or f) may be covered, at least partially, with carbon or a precursor of carbon.

In one embodiment, said particles of the melted product coated with carbon or a precursor of carbon represent more than 70%, more than 90%, more than 95%, more than 99%, substantially 100% by number of the particles of carbon. the powder, which advantageously makes it possible to improve the electrical conductivity, and therefore the performance of the battery comprising a cathode shaped from such a powder.

The deposition of carbon or carbon precursor is conventionally carried out by pyrolysis. Other methods can also be used, for example those described in EP 1 325 525 and EP 1 325 526.

An example of the second method according to the invention is now described in detail.

All the characteristics described above for step a) of the first method according to the invention are also applicable for step a ').

Substantially all the lithium, A, Fe, J, D, P and E components of the feedstock are found in the manufactured melt. Some of these constituents, for example manganese and / or lithium, vary depending on the melting conditions, but can volatilize during the melting step. Those skilled in the art know how to adapt the composition of the feedstock accordingly so as to obtain, after step c '), a molten product according to the invention.

In one embodiment, in step a '), preferably more than 99%, preferably substantially 100% by weight of the Fe element is provided by FePO ₄ , nH ₂ 0 with 0 <n <6. In one embodiment, in step a '), preferably more than 5%, or even more than 15%, or even more than 25% by weight of the Fe element is provided by Fe ₂ 0 ₃ .

In one embodiment, in step a '), preferably more than 99%, preferably substantially 100% by weight of the Fe element is provided by FeO.

In one embodiment, in step a '), preferably more than 10%, or even more than 15%, or even more than 25% by weight of the Fe element is provided by Fe ₃ 0 ₄ .

In step b '), the feedstock is melted until a liquid mass is obtained, at a temperature T _m i greater than the melting temperature T _f of the molten product obtained at the end of step e) and the temperature T _m i being such that:

o if the element Fe is provided for more than 97% of its mass by FePO ₄ , nH ₂ 0 with 0 <n <6, then T _m i is preferably greater than 1260 ° C, preferably greater than 1280 ° C and / or preferably below 1330 ° C, or

T _m i is greater than 1400 ° C, and / or less than 1500 ° C, or

o if the element Fe is brought for more than 5% of its mass by Fe ₃ 0 ₄ , then

T _m i is greater than 1400 ° C, and / or less than 1500 ° C, or

o if the element Fe is brought for more than 97% of its mass by FeO, then

T _m i may be less than 1050 ° C, or

o if the element Fe is provided for more than 97% of its mass by a mixture of FeO and FePO ₄ , nH ₂ 0 with 0 <n <6, said mixture comprising more than 3% and less than 97% of FePO ₄ , nH ₂ 0 with 0 <n <6, then T _m i is greater than 1260 ° C, preferably greater than 1280 ° C, and / or preferably less than 1330 ° C.

The inventors have found that, surprisingly, it is possible, under the conditions described above, to obtain, at the end of step c '), molten products having a phase ratio (Li _1-a A _a ). _{1 + x} _(b Fei- J _b) _y [(P0 ₄₎ i _d D _d] _z greater than 99.3%, without having recourse to a heat treatment such as that in step e) of the first method the invention.

It is nevertheless possible to perform a heat treatment step, as defined in step e) of the first method according to the invention after step d) of the second method according to the invention.

As for step b), one can for example use a Heroult-type arc furnace comprising two electrodes and whose vessel has a diameter of about 0.8 m and can contain about 180 kg of molten liquid. But all known ovens are such as an induction furnace, a plasma furnace or other types of Heroult furnaces, provided that they allow the initial charge to be completely melted.

Preferably, an arc furnace or an induction furnace is used.

Energy between 400 and 1200 kWh / T is well suited, especially for a product of molten LiFeP0 ₄ .

Without this being systematic, it is possible to increase the quality of stirring by bubbling a neutral gas as mentioned in FR 1 208 577. The stirring quality of the molten liquid can in particular be improved by sparging with nitrogen. The flow rate and / or the temperature of said gas are adapted so that the temperature of the liquid mass is not substantially affected by this addition of gas.

The inventors have found that surprisingly, in a second method according to the invention, the environment during the melting step b ') has little influence on the melted product obtained at the end of step c'). The operation of the process is advantageously simplified, the melting step b ') can be carried out in a neutral or oxidizing environment, preferably in air.

At the end of step b '), the feedstock is in the form of a liquid mass, which may optionally contain some solid particles, but in an amount insufficient for them to structure said mass. By definition, to maintain its shape, a liquid mass must be contained in a container.

All the characteristics described above for step c) of the first method according to the invention are also applicable for step c ').

All the characteristics described previously for step d) of the first method according to the invention are also applicable for step d ').

The melted products according to the invention can advantageously have various dimensions, the manufacturing process not being limited to obtaining submicron powders. It is therefore perfectly suited to industrial manufacturing.

They may be coated with a carbon layer or a layer of a carbon precursor. In a preferred embodiment, they are not coated with a carbon layer. Advantageously, the spectrum of possible uses is expanded.

The phase level LAGJXODE, and more generally the degree of crystallization, are preferably the highest possible. These rates can in particular be increased by reducing the cooling rate during solidification.

In addition, a powder according to the invention can advantageously be used to manufacture a cathode for lithium-ion batteries. For this purpose, the powder according to the invention can be mixed in a solvent with binders and a powder of carbon black. The mixture obtained is deposited on the surface of the current collector, generally aluminum, for example by scraping with the blade (or "doctor blade" in English) or by a roll-to-roll process (or "roll to roll") , to form the cathode. The cathode is then dried and / or hot rolled to evaporate the solvent, obtain good adhesion to the current collector and good contact between the grains of the cathode layer.

FIG. 1 represents a portion of a battery 2 constituted by a separator 4, an anode 6, a current collector 12 at the anode, a cathode 8 and a collector current 10 at the cathode, all these organs bathed in an electrolyte.

A battery is conventionally composed of several parts as described above. Examples

The following examples are provided for illustrative purposes and do not limit the invention. The melted products were manufactured in the following manner.

The following starting raw materials were first intimately mixed in a blender:

a lithium carbonate powder Li ₂ CO ₃ , the purity of which is greater than 99% by mass and the median size of which is less than 420 μηη;

a powder of FeP0 ₄ , 2.H ₂ 0, whose purity is greater than 99% by weight and whose median size is approximately 50 nm;

a powder of MnO ₂ , whose purity is greater than 91% by mass and whose median size is approximately 45 μηη.

For Examples 1 to 6, the feedstock, weighing 4 kg, was poured into a Héroult-type arc melting furnace. It was then melted according to a fusion with a voltage of 120 volts, an instantaneous power of 48 kW, and an applied energy substantially equal to 800 kWh / T, in order to melt the entire starting charge completely and homogeneously. The fusion took place under air. For the product according to Example 1, except for the invention, after melting of the feedstock, the mass of molten liquid was at a temperature T _m i measured at 1200.degree. In step c), the liquid mass was then cast to form a net.

Blow dry compressed air at room temperature and at a pressure of 8 bar broke the net and dispersed the molten liquid into droplets.

The blowing cooled these droplets and froze them in the form of melted particles. The cooling rate was between 300 K / s and 800 K / s.

Depending on the blowing conditions, the melted particles may be spherical or not, hollow or solid. They have a size between 0.005 mm and 5 mm.

For the product according to Example 2, manufactured according to the second process according to the invention, in step b '), after melting of the feedstock, the temperature T _m i of the molten liquid measured was equal to 1300 ° C. vs. The liquid mass was then cast in air, in cast iron molds as defined in US Pat. No. 3,993,199 and such that the thickness of the casting was 5 mm. The cooling rate was less than 500 K / s.

For example 3, manufactured according to the first method according to the invention, the steps a) to c) are identical to those carried out for the product according to example 1 outside the invention. In step d), 100 g of the melted product according to Example 1 were ground in an RS100 vibro-disc mill marketed by Retsch, so as to obtain a powder having a median size equal to 1 1 μηη. In step e), this powder was placed in an alumina box. Said box was placed in a Nabertherm HT 16/17 electric furnace, and connected to a circulation system of a 96 vol% N ₂ - 4 vol% H ₂ gas, making it possible to create a reducing environment in said box during treatment thermal. The powder was heated in this reducing environment for 5 hours at 700 ° C, the temperature rise rate being 100 ° C / h and the temperature descent rate being 100 ° C / h. After cooling, a product powder according to Example 3 was recovered in the box.

For the product according to Example 4, manufactured according to the second process according to the invention, in step b '), after melting of the feedstock, the temperature T _m i of the molten liquid measured was equal to 1275 ° C. vs. In step c '), the liquid mass was then cast to form a net. Blow dry compressed air at room temperature and at a pressure of 8 bar broke the net and dispersed the molten liquid into droplets. The blowing cooled these droplets and froze them in the form of melted particles. The cooling rate was between 300 K / s and 800 K / s. For the products according to Examples 5 and 6, produced according to the second process according to the invention, in step b '), after melting of the feedstock, the temperature T _m i of the molten liquid measured was equal to 1260 ° C and 1320 ° C, respectively. Step c ') is identical to that of the product of Example 4.

Chemical analyzes and phase determination were performed on samples which, after grinding, had a median size of less than 40 μηη.

Chemical analysis was performed by X-ray fluorescence and Inductively Coupled Plasma or ICP for lithium and impurities.

The determination of the LAGJXODE phase rate was carried out on the basis of the X-ray diffraction diagrams, acquired with a BRUKER D5000 diffractometer provided with a copper DX tube.

Using the EVA software (marketed by the BRUKER company) and after performing a subtraction of the continuous background (background 0.8), it is possible to measure the ALAGJXODE area (without deconvolution treatment) of the main peak or multiplet The main diffraction pattern of the LAGJXODE and, for each of the secondary phases, the area A _ps (without deconvolution treatment) of the peak of greater non-superimposed intensity or the multiplet of higher intensity not superimposed. We can then calculate the total area A secondary _ph ases by the sum of the areas A _ps. The LAGJXODE phase rate is then calculated according to formula (1).

Thus, if the LAGJXODE phase is the only phase present in the X diffraction diagram, the LAGJXODE phase rate is equal to 100%.

The determination of the mass quantity of amorphous phase was carried out on the basis of the X-ray diffraction diagrams, obtained from a BRUKER D8 Discover diffractometer type apparatus provided with a copper DX tube and a 2D meter. GADDS, also marketed by BRUKER, with an incidence angle of 7 °.

The acquisition of the diffraction diagrams is carried out from this equipment, on an angular range 2Θ between 14 ° and 80 °, on a window of 19 ° and with a counting time of 72s / window. The sample is rotated on itself in order to limit the preferential orientations and obtain average information.

The diagrams obtained are processed using the EVA software as follows:

The first step is to remove the baseline from the background noise (or linear processing). This function has two adjustment values: "Threshold" and "Curvature". This subtraction is performed with the value of "Threshold" appropriate and without "Curvature". This baseline is subtracted from the initially obtained chart. Diagl diagram is obtained.

The second step is to model a single diffraction peak associated with an amorphous phase, when present. The "Enhanced" function of the EVA software makes it possible to model a single diffraction peak associated with an amorphous phase in the angular range 2Θ between 20 ° and 30 ° when an amorphous phase is present. When this is not the case, the software tries to find a mathematical solution to 2Θ higher angles (typically greater than 40 °), which is an indication that no amorphous phase can be simulated. In this case, the mass quantity of amorphous phase is considered to be zero. When a peak can be simulated in an angular range 2Θ between 20 ° and 30 °, this peak is subtracted from the Diagl diagram in order to obtain the Diag2 diagram.

The third step consists of measuring the areas under the peaks of Diagl and Diag2 diagrams obtained. This area measurement is performed using the "Function net area" function of the EVA software.

The mass quantity of amorphous phase, expressed as a percentage, is equal to:

100 x [1 - (peak area of Diag2 / area of Diagl peaks)]

The products of Examples 1 to 6 did not contain an amorphous phase, according to the method described above.

Tables 1 and 2 summarize the results obtained:

( ^* ): excluding the invention

Table 1

5 Chemical analysis (mass percentages)

Oxygen level is the 100% complement

Phase LiAGJXODE phase

Ex. Li Fe P Mn Al Zr Other LAGJXODE

1 ( ^* ) 4.63 32 19.1 0.2 <0.1 <0.1 <0.1 Lh _, o ₈ Feo _{, 93} P0 ₄ 95.6%

2.444 31, 8 18.9 0, 1 <0.1 <0.1 <0.1 Lh _, o ₅ Feo _{, 93} P0 ₄ > 99.9%

3.63 32 19.1 0.2 <0.1 <0.1 <0.1 Lh _, o ₈ Feo _{, 93} P0 ₄ > 99.9%

4 4.50 31, 7 19.5 <0.1 <0.1 <0.1 <0.1 Lh _, o ₃ Feo _{, 9} oP0 ₄ > 99.9%

4.18 33.6 16.7 <0.1 <0.1 <0.1 <0.1 Lii, i2Fe-i 11 PO4> 99.9%

6 4.20 30.4 17.2 3.30 <0.1 <0.1 <0.1 Lii, o9Fe ₀ , 98Mno, iiP0 ₄ 99.7%

( ^* ): excluding the invention

Table 2 These examples make it possible to demonstrate the effectiveness of the processes according to the invention.

A comparison of the results of the fusions of Examples 1 and 2 shows that a melted product having a phase ratio (Li ₁ -a A _a ) _{1 + x} (G ₁ -b Jb) y [(XO 4) i -dDd] zEe greater than 99.3% is not obtained if the Fe element is provided by FeP0 ₄ , 2.H ₂ 0 with a temperature of the liquid mass, T _m i, equal to 1200 ° C, and without step e) heat treatment. On the contrary, the product of Example 2, produced according to the second process according to the invention, with the element Fe provided for substantially 100% of its mass by FePO ₄ , 2.H ₂ O in step a ') and with a temperature of the liquid mass T _m i equal to 1300 ° C in step b '), has a phase ratio (Li _1-a A _a ) _{1 + x} (G ₁ -b Jb) y [( X04) i-dDd] zEe greater than 99.9%.

A comparison of the results of the fusions of Examples 1 and 4 shows that a product having a phase ratio (Li ₁ -a A _a ) _{1 + x} (G ₁ -bJb) y [(XO 4) i -dDd] zE _e greater than 99.3%, is obtained if the Fe element is provided by FePO ₄ , 2.H ₂ O with a temperature of the liquid mass, T _m i, equal to 1300 ° C, and without step e) heat treatment, step c) for the product according to example 1 and step c ') for the product according to example 4 being identical. The product according to Example 4 has a phase ratio (Li ₁ -a A _a ) _{1 + x} (G ₁ -bJb) y [(XO 4) i -dDd] zE _e greater than 99.9%.

A comparison of the products of Examples 1 and 3 shows that a product having a phase content Li _{1 08} Feo _{, 93} PO ₄ greater than 99.9% can be obtained by the first method according to the invention comprising a heat treatment step e). As it is now clear, the process according to the invention makes it possible to manufacture in a simple and economical manner, in industrial quantities, molten products whose crystallized part comprises more than 99.3% LAGJXODE phase.

The dimensions of these products can be reduced, for example by grinding in the form of powders if their use requires it. These products can also be obtained directly in the form of particles.

Of course, the present invention is not limited to the described embodiments provided by way of illustrative and non-limiting examples.

In particular, the products according to the invention are not limited to particular shapes or dimensions.

Claims

Process for manufacturing a molten product comprising the following steps: a) mixing raw materials so as to form a feedstock, b) melting the feedstock until a liquid mass is obtained at a temperature T _m i greater than the melting temperature T _f of the molten product obtained at the end of step e),

c) cooling until complete solidification of said liquid mass, so as to obtain a molten product whose mass quantity of amorphous phase is less than 80%

d) optionally, crushing and / or grinding and / or granulometric selection of said melted product,

e) optionally, heat treatment of the molten product at a temperature below the melting temperature T _{f of} said molten product and between T _f - 800 ° C, or 500 ° C if T _f - 800 ° C is less than 500 ° C, and T _f - 50 ° C, during a hold time greater than 90 minutes, and in a reducing environment,

the raw materials in step a) and, optionally, the gaseous environment in step b) being determined so that said molten product has a crystallized portion consisting, for more than 99.3% by weight, of same crystalline phase of formula (Li _1- aA _a ) _{1 + x} (G ₁ -b Jb) y [(XO 4) i -dDd] zEe, or "phase LAGJXODE", in which:

Li is the lithium element,

A is a lithium substituent selected from the elements Na, K, H and mixtures thereof, a being less than or equal to 0.2,

G is selected from Fe, Mn, Ni, Co, V and mixtures thereof,

J is a substituent of G selected from Nb, Y, Mg, B, Ti, Cu, Cr and mixtures thereof, b being less than or equal to 0.5,

X0 ₄ is an oxoanion in which O denotes the oxygen element and X is chosen from P, S, Si, Nb, Mo and their mixtures,

D is selected from F ^" , OH ^" , CI ^" anions and mixtures thereof, d being less than or equal to 0.35, E being selected from the F element, the Cl element, the OH group, and mixtures thereof,

0 <e <2,

-0.2 <x <2,

- 0.9 <y <2,

1 <z <3.

The method of manufacturing a molten product according to claim 1, wherein the heat treatment of step e) is performed.

3. Method according to the preceding claim, wherein in step e), the temperature of the heat treatment is greater than T _f - 700 ° C and / or lower than T _f - 50 ° C.

4. Method according to the preceding claim, wherein in step e), the temperature of the heat treatment is greater than T _f - 600 ° C and / or lower than T _f - 80 ° C.

5. Method according to the preceding claim, wherein in step e), the temperature of the heat treatment is greater than T _f - 530 ° C and / or less than T _f - 130 ° C.

6. Method according to the preceding claim, wherein in step e), the temperature of the heat treatment is greater than T _f - 480 ° C and / or less than T _f - 180 ° C.

7. Method according to the preceding claim, wherein in step e), the temperature of the heat treatment is greater than T _f - 430 ° C and / or lower than T _f - 230 ° C.

8. Method according to the preceding claim, wherein in step e), the temperature of the heat treatment is greater than T _f - 380 ° C.

9. Method according to the preceding claim, wherein in step e), the temperature of the heat treatment is greater than T _f - 330 ° C.

10. A method according to any one of the preceding claims, wherein in step e), the dwell time is greater than 2 hours and / or less than 24 hours.

1 1. Method according to the preceding claim, wherein in step e), the dwell time is less than 10 hours.

12. The method as claimed in any one of the preceding claims, in which, when G is not the Fe element, in step b), the temperature of the liquid mass T _m i is less than T _f + 300 °. vs.

13. The method as claimed in any one of the preceding claims, in which, when G is not the Fe element, in step b), the temperature of the liquid mass T _m i is less than T _f + 150 °. vs.

14. Process according to any one of claims 1 to 1 1, wherein the formula of the molten product is such that e = 0, G is Fe and X is P, said temperature T _m i of step b) being such than :

if the element Fe is provided for more than 97% of its mass by FePO ₄ , nH ₂ 0 with 0 <n <6, then T _m i is greater than 1250 ° C, and preferably less than 1350 ° C, or

if the element Fe is brought for more than 3% of its mass by Fe ₂ 0 ₃ , then

T _m i is greater than 1350 ° C, and preferably less than 1550 ° C, or if the Fe element is provided for more than 5% of its mass by Fe ₃ O ₄ , then

T _m i is greater than 1350 ° C, and preferably less than 1550 ° C, or if the element Fe is provided for more than 97% of its mass by FeO, then

T _m i is preferably less than 1100 ° C,

if the element Fe is provided for more than 97% of its mass by a mixture of FeO and FePO ₄ , nH ₂ O with 0 <n <6, said mixture comprising less than 97% FePO ₄ , nH ₂ O with 0 <n <6, then T _m i is greater than 1250 ° C, and preferably less than 1350 ° C.

15. Method according to the preceding claim, wherein, in step b),

the element Fe is provided for more than 99% of its mass by FePO ₄ , nH ₂ O with 0 <n <6, or

the Fe element is added for more than 5% of its mass by Fe ₂ 0 ₃ , or the Fe element is added for more than 10% of its mass by Fe ₃ O ₄ , or the Fe element is added for more 99% of its mass by FeO.

16. The method according to the preceding claim, wherein, in step b),

the element Fe is provided for substantially 100% of its mass by FePO ₄ , nH ₂ O with 0 <n <6, or

the Fe element is provided for more than 15% of its mass by Fe ₂ O ₃ , or the Fe element is added for more than 25% of its mass by Fe ₃ O ₄ , or the Fe element is provided for substantially 100% of its mass by FeO.

17. A method according to any one of the three immediately preceding claims, wherein in step b), if the element Fe is provided for more than 97% of its mass by FePO ₄ , nH ₂ 0 with 0 <n <6, then T _m i is greater than 1260 ° C, and / or preferably less than 1330 ° C , or

T _m i is greater than 1400 ° C, and / or less than 1500 ° C, or

if the element Fe is brought for more than 5% of its mass by Fe ₃ 0 ₄ , then

T _m i is greater than 1400 ° C, and / or less than 1500 ° C, or

if the element Fe is brought for more than 97% of its mass by FeO, then

T _m i is preferably less than 1050 ° C, or

if the element Fe is provided for more than 97% of its mass by a mixture of FeO and FePO ₄ , nH ₂ 0 with 0 <n <6, said mixture comprising more than 3% and less than 97% of FePO ₄ , nH ₂ 0 with 0 <n <6, then T _m i is greater than 1260 ° C, and preferably less than 1330 ° C.

18. Method according to the preceding claim, wherein in step b),

if the element Fe is provided for more than 97% of its mass by FePO ₄ , nH ₂ 0 with 0 <n <6, then T _m i is greater than 1280 ° C, or if the element Fe is brought for more 97% of its mass with a mixture of FeO and FePO ₄ , nH ₂ 0 with 0 <n <6, said mixture comprising more than 3% and less than 97% of FePO ₄ , nH ₂ 0 with 0 <n < 6, then T _m i is greater than 1280 ° C.

19. A method according to any one of the five immediately preceding claims, wherein no step e) is performed.

20. A method according to any one of the preceding claims wherein in step b) the melting takes place in a neutral environment or containing oxygen.

21. Process according to the preceding claim, wherein in step b), the melting takes place under air.

22. The method according to claim 1, wherein in cooling step c), the cooling rate is less than 1000 K / s.

23. Method according to the preceding claim wherein in step c) of cooling, the cooling rate is less than 500 K / s.

24. The method of any one of the preceding claims, wherein a <0, 15.

25. The method according to the preceding claim, wherein a <0, 1.

26. Process according to the preceding claim, in which a = 0.

27. A process according to any one of the preceding claims, wherein G is selected from Fe, Co, Mn, V and mixtures thereof.

28. Process according to the preceding claim, in which G is chosen from Fe, Co, Mn and their mixtures.

29. The process as claimed in the preceding claim, in which G is Fe.

30. The method of any one of the preceding claims, wherein b <0.40.

31. Method according to the preceding claim, wherein b <0, 15.

32. A process according to any one of the preceding claims wherein the substituent element J is selected from Nb, Y, Mg, B, Ti and mixtures thereof.

33. A process according to any one of the preceding claims wherein X is selected from P, S, Si and mixtures thereof.

34. Method according to the preceding claim, in which X is the element P.

The process of any one of the preceding claims, wherein d <0.30.

36. The method according to the preceding claim, wherein d <0, 10.

37. Method according to the preceding claim, in which d = 0.

38. The method of any one of the preceding claims, wherein D is F ^" .

39. The method of any of the preceding claims, wherein E is the F element.

40. The method of any of the preceding claims, wherein x≥ -0.1 and / or x <1, 3.

41. Method u according to the preceding claim, wherein x≥ -0.05 and / or x <1, 2.

42. The method according to the preceding claim, wherein x≥ 0 and / or x <1.

43. The method of any one of the preceding claims, wherein y = 2.

44. A process according to any one of claims 1 to 42, wherein y <1, 5.

45. Method according to the preceding claim, wherein y≥ 1.

46. The method according to the preceding claim, wherein y = 1.

47. The method of any one of the preceding claims, wherein e = 2.

48. The method of any one of claims 1 to 46, wherein e <1.5.

49. Method according to the preceding claim, in which e <1.

50. The method according to the preceding claim, wherein e = 1.

51. A molten product according to any one of claims 1 to 46, wherein e = 0.

52. Process according to any one of the preceding claims, in which the crystallized part consists, for more than 99.7% by weight, of said LAGJXODE phase.

53. Method according to the preceding claim, wherein the crystallized portion is constituted, for more than 99.9% by weight, said LAGJXODE phase.

54. The process as claimed in any one of the preceding claims, wherein said LAGJXODE phase is chosen from the group formed by LiFePO ₄ , Li ₃ V ₂ (PO 4) ₃ , LiMnPO ₄ , Li ₂ FeSiO ₄ , LiVPO ₄ F, LiCoPO _4. , LiMn _0.8 _{Feo 2} P0 _4, LiFe _0, ₀ 33mn, 67PO ₄ LiFeP0 ₄ F, LiFeS0 ₄ F, Li ₂ CoP0 ₄ F, and LiVP0 _4.

The method of any of the preceding claims, wherein said mass quantity of amorphous phase is less than 50%, based on the mass of the melt.

56. Method according to the preceding claim, wherein the mass quantity of amorphous phase is less than 30%, based on the mass of the molten product.

57. Method according to the preceding claim, wherein the mass quantity of amorphous phase is less than 10%, based on the mass of the molten product.

58. Method according to the preceding claim, wherein the mass quantity of amorphous phase is less than 5%, based on the mass of the molten product.

59. A molten product obtained by a process according to any one of the preceding claims.

60. Particle powder in a product according to the preceding claim.

61. Powder according to the preceding claim, in which more than 50% by number, particles are not covered, even partially, carbon.

62. Powder according to the preceding claim, in which more than 95% by number of the particles are not covered, even partially, with carbon.

63. Powder according to any one of the three immediately preceding claims, in which the crystallized part comprises less than 30% of LAGJXODE phases in which the iron has a valence greater than or equal to 3, and in particular

64. Cathode for lithium-ion batteries comprising a melted product according to claim 59, or a powder according to any one of claims 60 to 63.

65. Battery comprising a cathode according to the preceding claim.