Nickel phosphate binary glasses, their production process, and their uses

Abstract

The present invention relates to binary nickel phosphate glasses and a process for their production. The invention also relates to the preparation and use of said glasses as active materials for positive electrodes, particularly in metal-ion batteries, as well as to said active materials and electrodes per se. (no figure)

Description

Title of the invention: Nickel phosphate binary glasses, their method of production, and their uses

[0001] The present invention relates to binary nickel phosphate glasses, as well as a process for obtaining them. The invention also relates to the preparation and use of said glasses as active materials for positive electrodes, in particular for metal-ion batteries, as well as said active materials and electrodes per se.

[0002] LiCoO2 (LCO) is the technology used for the positive electrode of the first lithium-ion battery marketed by Sony in 1991. This technology offers very high energy density and is relatively easy to implement. However, the instability associated with the use of cobalt dioxide (CoO2) makes this technology unreliable from an industrial standpoint, and speculation surrounding cobalt prices increases its cost.

[0003] Among the other well-established positive electrode technologies for Li-ion batteries, LiFePO4 (LFP) is a technology known for its very good power and cycling characteristics, while also having the great advantage of having high intrinsic safety and a very good lifespan, whether calendar or cycling.

[0004] However, the theoretical capacity of LiFePO4 (170 mAh / g) combined with an average operating voltage of 3.2V is an obstacle to its application in batteries requiring high energy densities. This constraint is illustrated by the limited range of electric vehicles (less than 160 km) equipped with such technology, which limits their widespread adoption.

[0005] To increase energy densities, it is generally necessary to develop new cathode materials beyond LFP and LCO that are capable of exchanging more than one Li per transition metal.

[0006] The development of glass-based positive electrodes is a promising approach, particularly because this material is easily synthesized. Furthermore, the glassy network theoretically allows for the easy incorporation of alkali ions exchanged during cycling. Due to the numerous accessible oxidation states of vanadium, vanadate-based glass electrodes have been considered as attractive alternatives. Currently, the best performance for a vanadium-based glass is achieved by a material based on the Li2O-B2O3-V2O5 system, reaching 1000 Wh / kg at the scale of the active material over 10 cycles.

[0007] However, this material remains limited by a fairly low operating potential (2.4 V vs Li+ / Li) and especially by its extremely low first charge (20 mAh / g).

[0008] In addition, vanadium poses toxicity and cost problems which limit its long-term application in the electric mobility sector or stationary storage in particular.

[0009] One objective of the invention is therefore to provide compounds which do not have the aforementioned disadvantages.

[0010] In particular, an objective of the invention is to provide compounds that can be used successfully for the preparation of positive electrodes, in particular metal-ion accumulators (the metal being in particular an alkali or alkaline earth metal, for example Li, Na, K, Mg or Ca), having high capacities and / or high energy densities, in particular higher than those relating to prior art devices, while avoiding economically critical and / or toxic metals, such as cobalt or vanadium.

[0011] Also, the invention relates to a glass of the following formula (I):

[0012] x NiO - (100-x) P2O5 (I),

[0013] with 50 <x<100.

[0014] By "glass" is meant in particular a metastable amorphous or substantially amorphous solid compound.

[0015] By "amorphous", we mean in particular a solid compound exhibiting no ordered atomic structure at medium and long distances.

[0016] By "substantially amorphous", it is understood in particular that the compound is more than 97%, in particular more than 98 or 99% amorphous by mass.

[0017] The amorphous character can be determined by any technique well known to those skilled in the art, in particular by ray diffraction (XRD).

[0018] According to a particular embodiment, x > 51, with in particular x > 52.

[0019] According to a particular embodiment, x < 95, with in particular x < 90, 85, 80, 75, 70, 60, 59, 58, 57, 56, or 55.

[0020] According to a particular embodiment, the invention relates to a glass as defined above, the formula of which is chosen from the following formulas: 55 NiO - 45 P2O5; or 52 NiO - 48 P2O5.

[0021] For any particular formula (I) or (Io) given, each value of x and y is understood to be within ±0.5%, or even ±1% or ±2%. Thus, by way of example, a value of x or y of 55 ± 1% includes the values ​​from 54.45 to 55.55. According to another aspect, the invention also relates to a method for preparing a glass as defined above, comprising a step (i) of quenching a molten mixture (A), which consists of or comprises a NiO source and a P2O5 source, to obtain said glass.

[0022] All embodiments described above relating to the glass of the invention also apply here, alone or in combination.

[0023] According to another aspect, the invention also relates to a method for preparing a glass of the following formula (Io):

[0024] x NiO - (100-x) P2O5 (Io),

[0025] with 15 <x<100, notamment 20<x<100 ou 30<x<100, en particulier 40<x<100,

[0026] said process comprising a step (i) of quenching a molten mixture (A), which consists of or comprises a NiO source and a P2O5 source, to obtain said glass.

[0027] All embodiments described above relating to the glass of the invention also apply here, alone or in combination.

[0028] According to a particular embodiment, the hardening can be carried out by casting onto a plate, for example metallic, or be carried out under mechanical stress, for example by drop hammer.

[0029] According to a particular embodiment, the process as defined above comprises: - a step (i) of quenching a molten mixture (A), which consists of or comprises a source of NiO and a source of P2O5, to obtain an intermediate glass; - a step (ii) of crushing the intermediate glass obtained at the end of step (i); - a step (iii) of tempering the crushed intermediate glass obtained at the end of step (ii), previously molten, to obtain the glass as defined above.

[0030] According to a particular embodiment, the molten mixture of step (i) as described above, and / or of step (iii) as described above, is, prior to quenching, at a temperature Tb of between 1200°C and 1500°C, for example of about 1400°C.

[0031] By “quenching”, we mean in particular a change from temperature Tb to a lower temperature, in particular ambient temperature, at a rate greater than or equal to about 1000°C / min for a cast quench on a plate and greater than or equal to about 10000°C / min for a drop hammer type quench.

[0032] This hardening can in particular be carried out in the air, on a metal plate, for example made of steel.

[0033] According to a particular embodiment, step (i) as described above, is preceded by a temperature ramp-up step, from a temperature Ta to the temperature Tb, the temperature Ta being in particular from 100°C to 400°C, in particular from about 300°C, at a heating rate of 60°C / h to 120°C / h, for example about 90°C / h.

[0034] According to a particular embodiment, the molten mixture of step (iii) as described above is obtained by introducing the crushed intermediate glass of step (ii), as described above, directly at a temperature Tb of 1200°C to 1500°C, for example about 1400°C.

[0035] According to a particular embodiment, the process according to the invention, as defined above, comprises: - A step (i0) of raising the temperature of a mixture (A) consisting of or comprising a source of NiO and a source of P2O5, from a temperature Ta to a temperature Tb, the temperature Ta being in particular between 100°C and 400°C, in particular about 300°C, the temperature Tb being in particular between 1200°C and 1500°C, for example about 1400°C, at a heating rate of 60°C / h to 120°C / h, for example about 90°C / h, to obtain a molten mixture (A); - a step (i) of quenching the molten mixture (A), to obtain said glass.

[0036] According to a particular embodiment, the process according to the invention, as defined above, comprises: - A step (i0) of raising the temperature of a mixture (A) consisting of or comprising a source of NiO and a source of P2O5, from a temperature Ta to a temperature Tb, the temperature Ta being in particular between 100°C and 400°C, in particular about 300°C, the temperature Tb being in particular between 1200°C and 1500°C, for example about 1400°C, at a heating rate of 60°C / h to 120°C / h, for example about 90°C / h; - a step (i) of quenching a molten mixture (A), which consists of or comprises a source of NiO and a source of P2O5, to obtain an intermediate glass; - a step (ii) of crushing the intermediate glass obtained at the end of step (i); - a step (iii0) of raising the temperature of the crushed intermediate glass to a temperature Tb between 1200°C and 1500°C, for example about 1400°C; - a step (iii) of tempering the molten crushed intermediate glass obtained at the end of step (iii0), to obtain the glass as defined previously.

[0037] According to a particular embodiment, the process according to the invention, as defined above, comprises: - A step (i0) of raising the temperature, under stirring, of a mixture (A) consisting of or comprising a source of NiO and a source of P2O5, from a temperature Ta to a temperature Tb, the temperature Ta being in particular between 100°C and 400°C, in particular about 300°C, the temperature Tb being in particular between 1200°C and 1500°C, for example about 1400°C, at a heating rate of 60°C / h to 120°C / h, for example about 90°C / h, to obtain a molten mixture (A); - a step (i) of quenching the molten mixture (A), to obtain said glass.

[0038] According to a particular embodiment, the stirring during step (i0) is mechanical stirring, in particular by a rod stirrer.

[0039] According to a particular embodiment, the NiO source comprises or is made up of NiO, Ni2O3, and / or NiSO4.

[0040] According to a particular embodiment, the P2O5 source comprises or is made up of NH4H2PO4, P2O5, (NaPO3)6, H3PO4, and / or (NH4)2HPO4.

[0041] According to another aspect, the invention also relates to a glass that can be obtained according to one of the processes defined above.

[0042] According to another aspect, the invention also relates to a powder made up of or comprising glass particles as defined above.

[0043] According to a particular embodiment, the particles have a size ranging from 0.1 to 100 pm, in particular from 0.1 to 50 pm, especially from 1 to 50 pm.

[0044] According to a more particular embodiment, the particles have a size ranging from 0.1 to 5 or even 2 pm.

[0045] All embodiments described above relating to the glass of the invention also apply here, alone or in combination.

[0046] According to another aspect, the invention also relates to a powder made up of or comprising glass particles of the following formula (Io):

[0047] x NiO - (100-x) P2O5 (Io),

[0048] with 15 <x<100, notamment 20<x<100 ou 30<x<100, en particulier 40<x<100.

[0049] All embodiments described above relating to the glass of the invention also apply here, alone or in combination.

[0050] According to a particular embodiment, the powder as defined above is devoid of KBr.

[0051] According to a particular embodiment, the particles have a size ranging from 0.1 to 100 pm, in particular from 50 to 100 pm, or from 0.1 to 50 pm, in particular from 1 to 50 pm.

[0052] According to a more particular embodiment, the particles have a size ranging from 0.1 to 5 or even 2 pm.

[0053] By "size" we mean in particular the largest dimension of a particle.

[0054] This size is in particular an average size, as for example determined by laser particle size analysis.

[0055] According to another aspect, the invention also relates to a powder made up of or comprising glass particles as defined above and an electronically conductive additive.

[0056] The electronically conductive additive, well known to those skilled in the art, may consist of or comprise hard carbon and / or graphite.

[0057] According to another aspect, the invention also relates to a powder made up of or comprising glass particles as defined above and carbon particles.

[0058] All embodiments described above relating to the glass and / or glass particles of the invention also apply here, alone or in combination.

[0059] According to a particular embodiment, the particles have a size ranging from 0.1 to 100 pm, in particular from 0.1 to 50 pm, especially from 1 to 50 pm.

[0060] According to a more particular embodiment, the particles have a size ranging from 0.1 to 5 or even 2 pm.

[0061] By "carbon particles" we mean particles constituting carbon black.

[0062] By "carbon black" is meant in particular a powdery composition of carbon in amorphous form, which is in particular in the form of a powder consisting of or comprising spherical or spheroid particles of 5 to 500 nm (largest dimension), in particular less than 100 nm.

[0063] According to another aspect, the invention also relates to a powder made up of or comprising glass particles and an electronically conductive additive, in particular carbon particles, the glass having the following formula (Io):

[0064] x NiO - (100-x) P2O5 (Io),

[0065] with 15 <x<100, notamment 20<x<100 ou 30<x<100, en particulier 40<x<100.

[0066] All embodiments described above relating to the glass and / or glass particles of the invention also apply here, alone or in combination.

[0067] According to a particular embodiment, the glass particles are mixed with particles of an electronically conductive additive, in particular carbon, thus constituting a composite material. In this composite, the particles of the electronically conductive additive, in particular carbon, are distributed such that they envelop the glass particles.

[0068] According to a particular embodiment, the ratio of the mass of the glass particles to the mass of the particles of electronically conductive additive, in particular carbon, is from 90 / 5 to 50 / 40, this ratio being for example 70 / 25.

[0069] According to another particular embodiment, the ratio of the mass of the glass particles to the mass of the electronically conductive additive particles, in particular carbon, is from 96 / 2 to 90 / 5.

[0070] According to another aspect, the invention also relates to a powder made up of or comprising glass particles as defined above, an electronically conductive additive, in particular carbon particles, and a binder.

[0071] All embodiments described above relating to the glass and / or glass particles of the invention also apply here, alone or in combination.

[0072] According to another aspect, the invention also relates to a powder made up of or comprising glass particles, an electronically conductive additive, in particular carbon particles, and a binder, the glass having the following formula (Io):

[0073] x NiO - (100-x) P2O5 (Io),

[0074] with 15 <x<100, notamment 20<x<100 ou 30<x<100, en particulier 40<x<100.

[0075] All embodiments described above relating to the glass and / or glass particles of the invention also apply here, alone or in combination.

[0076] According to a particular embodiment, the binder is a polymer, in particular chosen from polyvinylidene fluoride (PVDF).

[0077] According to a particular embodiment, the powder as defined above comprises, by mass:

[0078] -from 50 to 90% of glass particles as defined above, in particular 70%;

[0079] -from 5 to 40% carbon particles, in particular 25%; and

[0080] -from 5 to 10% binder, in particular 5%.

[0081] According to a particular embodiment, the powder as defined above comprises, by mass:

[0082] -from 90 to 96% of glass particles as defined above;

[0083] -2 to 6% of carbon particles, in particular; and

[0084] -2 to 4% binder.

[0085] According to another aspect, the invention also relates to a method for preparing a powder as defined above, comprising a step a) of grinding a glass as defined above.

[0086] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0087] According to a particular embodiment, the process of the invention as defined above comprises: a. a first grinding stage, in particular with balls, of a glass as defined above, to obtain a first glass powder; b. a second grinding step, in particular with balls, of a composition comprising the glass powder obtained at the end of the previous grinding, as well as a powder and an electronically conductive additive, in particular of carbon.

[0088] According to a more particular embodiment, the particles of the first glass powder have a size of 5 or even 10 to 20 pm.

[0089] Grinding according to step a) as described above can notably be carried out using a vibratory crusher or an attrition machine (erosion crushing). In the case of a vibratory crusher, the glass is typically placed in a grinding chamber containing one or more grinding media. By means of horizontal oscillations of the grinding chamber, the material is ground by impacts between the grinding media, the chamber, and the material to be ground.

[0090] Ball milling according to a step b) as described above can in particular be carried out using a planetary mill, or a centrifugal mill.

[0091] According to another aspect, the invention also relates to the use of a glass as defined above or of a powder as defined above for the production of an electrode, in particular a positive one, especially for a metal-ion battery or accumulator.

[0092] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0093] According to another aspect, the invention also relates to the use of a glass or a glass powder for the production of an electrode, in particular a positive one, especially for a metal-ion battery or accumulator, the glass having the following formula (Io):

[0094] x NiO - (100-x) P2O5 (Io),

[0095] with 15 <x<100, notamment 20<x<100 ou 30<x<100, en particulier 40<x<100.

[0096] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0097] According to another aspect, the invention also relates to an electrode, in particular a positive one, especially for a metal-ion battery or accumulator, comprising a glass as defined above or a powder as defined above.

[0098] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0099] According to another aspect, the invention also relates to an electrode, in particular a positive one, especially for a metal-ion battery or accumulator, comprising a glass or a glass powder, the glass having the following formula (Io):

[0100] x NiO - (100-x) P2O5 (Io),

[0101] with 15 <x<100, notamment 20<x<100 ou 30<x<100, en particulier 40<x<100.

[0102] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0103] According to another aspect, the invention also relates to a method for preparing an electrode, in particular a positive one, especially for a metal-ion battery or accumulator, said method comprising a step A) of bringing into contact a powder made up of or comprising glass particles, an electronically conductive additive, in particular carbon particles, and optionally a binder, as defined above, with a conductive support.

[0104] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0105] According to a particular embodiment, the conductive support is a metallic support, the metal being chosen in particular from Al and Cu.

[0106] According to a particular embodiment, the process of the invention as defined above comprises:

[0107] Ao) a step of preparing an ink by adding a solvent, in particular selected from N-methyl-2-pyrrolidone (NMP), or aqueous-based polymers (such as carboxymethylcellulose), to a powder consisting of or comprising glass particles, an electronically conductive additive, in particular carbon particles and optionally a binder, the binder being for example previously dissolved in a solvent, in particular N-methyl-2-pyrrolidone (NMP), as defined above, and, optionally homogenization, in particular by mechanical stirring, to obtain a suspension;

[0108] A) a step A) of bringing into contact a suspension such as obtained at the end of step A), with a conductive support, in particular by coating, for example of the "doctor blade" type to obtain a device;

[0109] B) optionally, a drying step for said device;

[0110] C) optionally a shaping step, in particular by pelletizing, of said device, possibly dried, in particular at a temperature of 50°C to 100°C, in particular at about 60°C, and / or for 1 to 48 hours, for example for about 24 hours.

[0111] According to another aspect, the invention also relates to a battery or accumulator comprising a positive electrode, comprising a glass as defined above or a powder as defined above.

[0112] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0113] According to another aspect, the invention also relates to a battery or accumulator comprising an electrode, in particular a positive electrode, comprising a glass or a glass powder, the glass having the following formula (Io):

[0114] x NiO - (100-x) P2O5 (Io),

[0115] with 15 <x<100, notamment 20<x<100 ou 30<x<100, en particulier 40<x<100.

[0116] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0117] According to a particular embodiment, the cell or accumulator as defined above further comprises at least one electrolyte, a separator, in particular microporous, and / or a negative electrode, in particular made of or comprising a metal selected from Li, Na and K.

[0118] These elements are well known to the person skilled in the art, who will be able to select them, in particular from the elements of the trade, according to the needs.

[0119] The negative electrode may also be made of or comprising hard carbon or graphite.

[0120] According to a particular embodiment, the positive electrode material of the cell or accumulator, as defined above, has a theoretical specific capacity greater than 60 mAh / g, preferably greater than 100 mAh / g, preferably even greater than 120 mAh / g and even more preferably greater than 150 mAh / g, and finally preferably greater than 200 mAh / g.

[0121] The batteries or accumulators of the invention can, for example, be used in the field of electrical storage, particularly stationary, or in electric mobility, particularly for portable or wearable electronics, in integration into fibers and / or cables, in particular in the context of wired batteries, or for medical use.

[0122] In particular, the batteries or accumulators of the invention can be used in the field of electric mobility, in particular for electric vehicles, plug-in hybrid electric vehicles, hybrid vehicles, or electric 2-wheelers.

[0123] In particular, the batteries or accumulators of the invention can be used in the field of portable power equipment, in particular telephony, laptops, or portable tools.

[0124] According to another aspect, the invention also relates to a battery comprising a cell or accumulator as defined above.

[0125] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention, and / or an electrode, and / or a battery or accumulator also apply here, alone or in combination.

[0126] According to another aspect, the invention also relates to a portable or electric mobility-adapted electrical system, comprising a battery as defined above.

[0127] All embodiments described above relating to glass and / or glass particles, and / or a powder of the invention, and / or an electrode, and / or a battery or accumulator also apply here, alone or in combination. DEFINITIONS

[0128] As understood here, value ranges in the form of "xy" or "from x to y" or "between x and y" include the bounds x and y, the integers between these bounds, and all other real numbers between these bounds. For example, "1-5", or "from 1 to 5", or "between 1 and 5" refers to the integers 1, 2, 3, 4, and 5, as well as all other real numbers between 1 and 5. Preferred embodiments include each individual integer in the value range, as well as any subcombination of these integers and any set of real numbers between these integers. As an example, preferred values ​​for "1-5" may include the integers 1, 2, 3, 4, 5, 1-2, 1-3, 1-4, 1-5, 2-3, 2-4, 2-5, etc.

[0129] As used in this description, the term "approximately" refers to a range of values ​​within ±10% of a specific value. For example, the expression "approximately 20" includes values ​​within 20 ±10%, that is, values ​​from 18 to 22.

[0130] For the purposes of this description, percentages refer to percentages by mass relative to the total mass of the formulation, unless otherwise specified. FIGURES

[0131] Fig. 1 presents a thermal cycle for the production of 55 NiO - 45 P2O5 glass, according to example 1.

[0132] Figure 2 shows the first 7 galvanostatic cycles of 55NiO-45P2 glass O5 in Li-metal configuration, according to example 2. Cycling between 1.8V and 3.6V at C / 100, starting discharge - Theoretical capacity of 278 mAh / g for 2 electrons exchanged.

[0133] Figure 3 shows the first 19 galvanostatic cycles of 55 NiO - 45 P2O5 in Na-metal configuration, according to example 2. Cycling between 1.6V and 4.5V at C / 100, discharge start. Theoretical capacity used: 142 mAh / g.

[0134] Figure 4 shows the first 27 galvanostatic cycles of 55 NiO - 45 P2O5 in K-metal configuration, according to example 2. Cycling between 1.6V and 4.5V at C / 100, starting in discharge. Theoretical capacity used: 142 mAh / g.

[0135] Fig. 5 presents a thermal cycle for the production of 52 NiO - 48 P2O5 glass, according to example 3. EXAMPLES

[0136] Example 1: Preparation of 55 NiO - 45 P 2 O s glass according to the invention

[0137] The 55 NiO - 45 P2O5 vitrified material is produced by double quenching a molten iron bath (1400°C) by pouring it onto a metal plate. Following the first quench ([Fig. 1]), the material is crushed and then hot-returned to the furnace at 1400°C. This intermediate crushing can, if necessary, homogenize the molten liquid. It is held at this temperature for another 30 minutes before being quenched again onto a metal plate.

[0138] The melt bath is obtained by subjecting a mixture of precursor powders (NH4H2PO4 for P2O5 and NiO for NiO) to a specific heat treatment ([Fig.1]) allowing the elimination of unwanted chemical species (H2O and NH3), in particular between 150°C and 220°C for the moles of NH3.

[0139] The target molar proportions are obtained by adequately weighing the different precursor powders constituting the mixture, according to the following reaction equation:

[0140] 2(NH4H2PO4) + NiO -> [2 NH3 + 3 H2O] + P2O5 + NiO, before placing them in a Pt / Rh crucible. The raw material (without further heat treatment such as stabilizing annealing) is then analyzed to determine its amorphous character, its homogeneity and its actual chemical composition.

[0141] The amorphous nature of the material was confirmed by X-ray diffraction.

[0142] The elemental homogeneity of the glass was confirmed by Scanning Electron Microscopy (SEM) and the chemical composition was confirmed by Energy-Dispersive X-ray Spectroscopy (EDX). For this purpose, a polished section was prepared from the raw material. A number of EDX scans were performed on the entire polished section.

[0143] The chemical composition of the compound 55 NiO - 45 P2O5 as obtained by EDX is recorded in the table below: 55 NiO - 45 P2O5 %at. P %at. Ni 21.22 + 0.10 12.87 + 0.17 %mol P2O5 %mol NiO 45.18 + 0.01 54.82 + 0.01

[0144] The glass is then ground for 3 minutes at 30Hz via a vibratory grinder (Retsch MM400) in order to be shaped into a button cell for electrochemical characterization.

[0145] Example 2: Electrochemical characterizations of 55NiO-45P2Os glass according to the invention • Electrode preparation#

[0146] Initially, an intimate mixture of active material / carbon black (Super Carbon C65) in a mass ratio of 70 / 25 was prepared using a high-energy mill (PM 100 planetary mill) in dry mode. The milling protocol lasted a total of 6 hours at 300 rpm, alternating 5 minutes of milling with 5 minutes of rest (to avoid local heating that could lead to potential devitrification / crystallization), resulting in 3 hours of effective milling. The resulting powder was then characterized by X-ray diffraction to ensure that the glass / carbon mixture remained amorphous.

[0147] The resulting glass / carbon powder (i.e., composite material) is then mixed with 5 wt% polymer binder (a 10 wt% solution of polyvinylidene fluoride (PVDF) diluted in N-methyl-2-pyrrolidone (NMP)). An additional solvent (NMP) is then added to obtain an ink of acceptable viscosity for coating. This ink, consisting of a dispersion of composite particles in PVDF and NMP, is mechanically agitated (for 15 minutes at 1000 rotations per minute) using a mechanical disperser (Dispermat). This disperser homogenizes the dispersion and disperses the composite aggregates formed during the grinding step. The ink is then coated onto a sheet using the "doctor blade" method (coating table with a slotted doctor blade set at 100 µm). of aluminium, then dried for 24 hours at 60°C under air to remove residual solvent (NMP).

[0148] After drying, the resulting electrode is cut into 14 mm diameter discs, which are then pressed at 10 tonnes. The mass and thickness of the discs were measured. The discs are then vacuum-dried for 48 hours at 80°C to remove residual water. Finally, the electrodes are transferred to a glove box ([H2O] < 3 ppm, [O2] < 1 ppm) for mounting in button cells. • Making button batteries#

[0149] The electrodes are mounted in a configuration known as a half-button cell (CR2032 type), in a glove box, in a Li-metal, Na-metal, or K-metal configuration. The electrodes are arranged in a cover, inside of which an insulating gasket is affixed. Two separators are added to the electrode to be tested: a Viledon felt serving as an electrolyte reservoir, and a Celgard microporous separator preventing sodium dendritic growth. In the case of a K-ion cell, only one separator, the Whatmann separator, was used. A volume of 150 pL of electrolyte is added to the pipette filler. Then, the counter electrode, a metal foil (Li, Na, or K) deposited on a stainless steel block, is placed over the separators. A spring is added to the counter electrode, and then the half-button cell is closed with a small cap and crimped.

[0150] Depending on the configuration, the three electrolytes used are as follows: Li-metal: IM of LiPF6 in EC:DMC:EMC (1:1:1 vol.) Na-metal: IM of NaPF6 in EC:DMC (50% vol:50% vol.) + 2% mass of FEC K-metal: 0.7M of KPF6 in EC:DEC (50% vol.:50% vol.) + 2% mass of VC • Galvanostatic cycling#

[0151] The performance of the resulting battery is evaluated using an ARBIN-type test bench. The batteries are typically cycled at a C / 100 rate, at room temperature, with a potential window between 1.5V and 4.5V. Since the glass composition initially contains no alkali, all tests are initiated under discharge conditions. • Examples of galvanic cycling curves#

[0152] Figures 2 to 4 show examples of galvanic cycling curves.

[0153] Example 3: Preparation of glass 52 NiO - 48 P 2 O 5

[0154] Vitrified 52 NiO - 48 P2O5 is produced by simple quenching of a molten iron bath (1400°C) by pouring it onto a metal plate.

[0155] The melt bath is obtained by subjecting a mixture of precursor powders (NH4H2PO4 for P2O5 and NiO for NiO) to a specific heat treatment ([Fig.5]) allowing the elimination of unwanted chemical species (H2O and NH3).

[0156] The target molar proportions are obtained by adequately weighing the different precursor powders constituting the mixture, according to the following reaction equation:

[0157] 2(NH4H2PO4) + NiO -> [2 NH3 + 3 H2O] + P2O5 + NiO, before placing them in a Pt / Rh crucible.

[0158] The raw material (without further heat treatment such as stabilizing annealing) is then analyzed to determine its amorphous character, its homogeneity and its actual chemical composition.

[0159] The amorphous nature of the material was confirmed by X-ray diffraction.

[0160] The elemental homogeneity of the glass was confirmed by Scanning Electron Microscopy (SEM) and the chemical composition was confirmed by Energy-Dispersive X-ray Spectroscopy (EDX). For this purpose, a polished section is prepared from the raw material. A number of EDX scans are performed on the entire polished section.

[0161] The chemical composition of the compound 52 NiO - 48 P2O5 as obtained by EDX is recorded in the table below: 52 NiO - 48 P2O5 %at. P %at. Ni 21.85 + 0.07 11.76 + 0.12 mol% P2O5 mol% NiO 48.17 + 0.01 51.83 + 0.01

[0162] The glass is then ground for 3 minutes at 30Hz via a vibratory grinder (Retsch MM400) in order to be shaped into a button cell for electrochemical characterization.

[0163] Example 4: Electrochemical Characterizations of 52 NiO-48 P2Os Glass • Electrode preparation#

[0164] Initially, an intimate mixture of active material / carbon black (Super Carbon C65) in a mass ratio of 70 / 25 was prepared using a dry-process energy mill (PM 100 planetary mill). The milling protocol lasted a total of 6 hours at 300 rpm, alternating 5 minutes of milling with 5 minutes of rest (to avoid local heating that could lead to potential devitrification / crystallization), resulting in 3 hours of effective milling. The resulting powder was then characterized by X-ray diffraction to confirm that the glass / carbon mixture remained amorphous.

[0165] The resulting glass / carbon powder (i.e., composite material) is then mixed with 5 wt% polymer binder (a 10 wt% solution of polyvinylidene fluoride (PVDF) diluted in N-methyl-2-pyrrolidone (NMP)). An additional solvent (NMP) is then added to obtain an ink of acceptable viscosity for coating. This ink, consisting of a dispersion of composite particles in PVDF and NMP, is mechanically agitated (for 15 minutes at 1000 rotations per minute) using a mechanical disperser (Dispermat). This disperser homogenizes the dispersion and disperses the composite aggregates formed during the grinding step. The ink is then coated onto a sheet using the "doctor blade" method (coating table with a slotted doctor blade set at 100 µm). of aluminium, then dried for 24 hours at 60°C under air to remove residual solvent (NMP).

[0166] After drying, the resulting electrode is cut into 14 mm diameter discs, which are then pressed under a pressure of 10 tonnes. The mass and thickness of the discs were measured. The discs are then dried under vacuum for 48 hours at 80°C to remove residual water. Finally, the electrodes are transferred to a glove box ([H2O] < 3 ppm, [O2] < 1 ppm) for mounting in button cells. • Making button batteries#

[0167] The electrodes are mounted in a so-called half-button cell configuration (CR2032 type), in a glove box, in a Li-metal, Na-metal, or K-metal configuration. The electrodes are arranged in a lid, inside of which an insulating gasket is placed. Two separators are added to the electrode to be tested: a Viledon felt serving as an electrolyte reservoir, and a Celgard microporous separator preventing sodium dendritic growth. In the case of a K-ion cell, only one separator, the Whatmann separator, was used. A volume of 150 pL of electrolyte is added to the pipette filler. Then, the counter electrode, a metal foil (Li, Na, or K) deposited on a stainless steel block, is placed over the separators. A spring is added to the counter electrode, and then the half-button cell is closed with a small lid and crimped.

[0168] Depending on the configuration, the three electrolytes used are as follows: Lithium metal: IM of LiPF6 in EC:DMC:EMC (1:1:1 vol.) Na metal: IM of NaPF6 in EC:DMC (50% vol.:50% vol.) + 2% mass of FEC K metal: 0.7M of KPF6 in EC:DEC (50% vol.:50% vol.) + 2% mass of VC • Galvanostatic cycling#

[0169] The performance of the resulting battery is evaluated using an ARBIN-type test bench. The batteries are typically cycled at a C / 100 rate, at room temperature, with a potential window between 1.5V and 4.5V. Since the glass composition initially contains no alkali, all tests are initiated under discharge conditions.

Claims

Demands

1. Glass of the following formula (I): x NiO - (100-x) P2O5 (I), with 50 <x<100.

2. Glass according to claim 1, wherein: - x > 51, with in particular x > 52; and / or - x < 95, with in particular x < 90, 85, 80, 75, 70, 60, 59, 58, 57, 56, or 55; the glass being for example of a formula is chosen from the following formulas: 55 NiO - 45 P2O5; or 52 NiO - 48 P2O5.

3. A method for preparing a glass according to claim 1 or 2, comprising a step (i) of quenching a molten mixture (A), which consists of or comprises a source of NiO and a source of P2O5, to obtain said glass.

4. A process according to claim 3, comprising: - a step (i) of quenching a molten mixture (A), which consists of or comprises a source of NiO and a source of P2O5, to obtain an intermediate glass; - a step (ii) of crushing the intermediate glass obtained at the end of step (i); - a step (iii) of quenching the crushed intermediate glass obtained at the end of step (ii), previously molten, to obtain the glass according to claim 1 or 2; or wherein step (i) as described in claim 3 is preceded by a step of stirring the mixture (A).

5. A method according to any one of claims 3 to 4, wherein: - the NiO source comprises or is made up of NiO, Ni2O3, and / or NiSO4; and / or - the P2O5 source comprises or is made up of NH4H2PO4, P2O5, (NaPO3)6, H3PO4, and / or (NH4)2HPO4.

6. Powder consisting of or comprising glass particles as defined in any one of claims 1 to 2, in which the particles have a size ranging from 0.1 to 100 pm, in particular from 0.1 to 50 pm.

7. Powder according to claim 6, further comprising an electronically conductive additive, in particular carbon particles, and optionally, a binder.

8. Electrode, in particular positive, in particular for a metal-ion battery or accumulator, comprising a glass according to claim 1 or 2 or a powder according to claim 6 or 7.

9. A method for preparing an electrode, in particular a positive one, especially for a metal-ion battery or accumulator, said method comprising a step A) of contacting a powder made up of or comprising glass particles, an electronically conductive additive, in particular carbon particles, and optionally a binder, according to any one of claims 6 to 7, with a conductive support.

10. Battery or accumulator comprising an electrode, in particular a positive electrode, comprising a glass according to claim 1 or 2 or a powder according to claim 6 or 7, having in particular a theoretical capacity greater than 60 mAh / g.

11. Battery comprising a cell or accumulator according to claim 10.

12. A portable or electrically adapted system for electric mobility, comprising a battery according to claim 11.

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