SODIUM NICKEL PHOSPHATE TERNARY GLASSES, PROCESS FOR THEIR OBTAINING, AND THEIR USES

Abstract

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

Description

Title of the invention: SODIUM NICKEL PHOSPHATE TERNARY GLASSES, METHOD FOR PRODUCING THEM, AND THEIR USES

[0001] The present invention relates to sodium nickel phosphate ternary glasses, as well as to a process for their production. The invention also relates to the preparation and use of said glasses as active materials for positive electrodes, in particular metal-ion accumulators, 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 has a very high energy density and is relatively easy to implement. However, the instability associated with the exploitation of cobalt dioxide (CoO2) makes this technology unsafe from an industrial point of view and speculation around cobalt prices increases its price.

[0003] Among the other well-established Li-ion battery positive electrode technologies, LiFePO4 (LFP) is a technology known for its very good power and cycling characteristics, while having the great advantage of having high intrinsic safety and having 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 autonomy of electric vehicles (less than 160 km) equipped with such technology, which limits their large-scale introduction.

[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 positive electrodes based on glass is an interesting avenue, particularly because this material is easily synthesized. In addition, the vitreous network of glasses theoretically allows easy incorporation of the alkali ions exchanged during cycling. Due to the numerous accessible oxidation states of vanadium, vanadate-based glass electrodes have been considered as interesting alternatives. Currently, the best performances for a vanadium-based glass are held by a material based on the Li2O - B2O3- V2O5 system, making it possible to reach 1000 Wh / kg on 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 limiting its long-term application in the electric mobility or stationary storage sector in particular.

[0009] An objective of the invention is thus to provide compounds which do not have the aforementioned drawbacks.

[0010] In particular, an objective of the invention is to provide compounds capable of being successfully used 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 the devices of the prior art, 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 Na2O - y NiO - (100-xy) P2O5 (I),

[0013] with:

[0014] 0 <x<33, en particulier 0<x<25 ;

[0015] 10 <y<100 ;

[0016] 40 < x+y < 100.

[0017] By “glass” is meant in particular a metastable, amorphous or substantially amorphous solid compound.

[0018] By “amorphous” is meant in particular a solid compound having no atomic structure ordered at medium and long distance.

[0019] By "substantially amorphous" is meant in particular that the compound is more than 97%, in particular more than 98 or 99% amorphous by mass. The amorphous character can be determined by any technique well known to those skilled in the art, in particular by X-ray diffraction (XRD).

[0020] According to a particular embodiment, x < 32, with in particular x < 31, 30, 29, 28, 27, 26 or 25.

[0021] According to a particular embodiment, y <95, or even 90, 80, 70 or 60.

[0022] According to a particular embodiment, x < 32, with in particular x < 31, 30, 29, 28, 27, 26 or 25, and y <95, or even 90, 80, 70 or 60.

[0023] According to a particular embodiment, 0.5 < 2x / y < 2.5 or 3.0.

[0024] According to a particular embodiment, the invention relates to a glass as defined previously, whose formula is chosen from the following formulas: 15 Na2O - 27 NiO - 58 P2O5; Or 24 Na2O - 19 NiO - 57 P2O5.

[0025] For any given particular formula (I) or (Io), each value of x and y is understood to be within ± 0.5%, or even ± 1% or ± 2%. Thus, for example, a value of x or y of 55 ± 1%, includes the values ​​from 54.45 to 55.55.

[0026] 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 source of NiO, the source of Na2O and a source of P2O5, to obtain said glass.

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

[0028] According to another aspect, the invention also relates to a process for preparing a glass of the following formula (Io):

[0029] x Na2O - y NiO - (100-xy) P2O5 (Io),

[0030] with:

[0031] 0 <x<100

[0032] 10 < y < 100

[0033] x+y < 100, said method comprising a step (i) of quenching a molten mixture (A), which consists of or comprises a source of NiO, the source of Na2O and a source of P2O5, to obtain said glass.

[0034] All the embodiments described previously relating to the glass of the invention also apply here, alone or in combination.

[0035] According to a particular embodiment, x <95, or even 90, 80, 70 or 60.

[0036] According to a particular embodiment, y <95, or even 90, 80, 70 or 60.

[0037] According to a particular embodiment, x <95, or even 90, 80, 70 or 60, and y <95, or even 90, 80, 70 or 60.

[0038] According to a particular embodiment, the quenching can be carried out by casting onto a plate, for example a metal plate, or be accelerated by the application of mechanical stresses, for example by a drop hammer.

[0039] According to a particular embodiment, the method as defined previously comprises: - a step (i) of quenching a molten mixture (A), which consists of or comprises a source of NiO, the source of Na2O 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 melted, to obtain the glass as defined above.

[0040] 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 from 1000°C to 1400°C, for example approximately 1200°C.

[0041] By "quenching" is meant in particular a passage from the temperature Tb to a lower temperature, in particular ambient temperature, at a speed greater than or equal to approximately 1000°C / min for quenching cast on a plate and greater than or equal to approximately 10000°C / min for quenching of the drop hammer type.

[0042] This quenching can in particular be carried out in air, on a metal plate, for example steel.

[0043] According to a particular embodiment, step (i) as described above is preceded by a step of increasing the temperature, from a temperature Ta to the temperature Tb, the temperature Ta being in particular from 750°C to 900°C, in particular from approximately 800°C, at a heating rate of 60°C / h to 300°C / h, for example approximately 120°C / h.

[0044] 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 from 1000°C to 1400°C, for example approximately 1200°C.

[0045] According to a particular embodiment, the method according to the invention, as defined previously, comprises: - A step (i0) of raising the temperature of a mixture (A) consisting of or comprising a source of NiO, the source of Na2O and a source of P2O5, from a temperature Ta to a temperature Tb, the temperature Ta being in particular from 750°C to 900°C, in particular approximately 800°C, the temperature Tb being in particular from 1000°C to 1400°C, for example approximately 1200°C, at a heating rate of 60°C / h to 300°C / h, for example approximately 120°C / h, to obtain a molten mixture (A); - a step (i) of quenching the molten mixture (A), to obtain said glass.

[0046] According to a particular embodiment, the method according to the invention, as defined previously, comprises: - A step (i0) of increasing the temperature of a mixture (A) consisting of or comprising a source of NiO, the source of Na2O and a source of P2O5, from a temperature Ta to a temperature Tb, the temperature Ta being in particular between 750°C and 900°C, in particular around 800°C, the temperature Tb being in particular between 1000°C and 1400°C, for example around 1200°C, at a heating rate of 60°C / h to 300°C / h, for example around 120°C / h; - a step (i) of quenching a molten mixture (A), which consists of or comprises a source of NiO, the source of Na2O 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 introducing the crushed intermediate glass at a temperature Tb, the temperature Tb being in particular between 1000°C and 1400°C, for example approximately 1200°C; - a step (iii) of tempering the crushed intermediate glass in fusion obtained at the end of step (iii0), to obtain the glass as defined previously.

[0047] According to a particular embodiment, the method according to the invention, as defined previously, comprises: - A step (i0) of increasing the temperature, with stirring, of a mixture (A) consisting of or comprising a source of NiO, the source of Na2O and a source of P2O5, from a temperature Ta to a temperature Tb, the temperature Ta being in particular from 750°C to 900°C, in particular approximately 800°C, the temperature Tb being in particular from 1000°C to 1400°C, for example approximately 1200°C, at a heating rate of 60°C / h to 300°C / h, for example approximately 120°C / h, to obtain a molten mixture (A); - a step (i) of quenching the molten mixture (A), to obtain said glass.

[0048] According to a particular embodiment, the stirring during step (i0) is mechanical stirring, in particular by a rod stirrer.

[0049] According to a particular embodiment, the source of NiO comprises or consists of NiO, Ni2O3, and / or NiSO4.

[0050] According to a particular embodiment, the source of P2O5 comprises or consists of NH4H2PO4, P2O5, (NaPO3)6, H3PO4, and / or (NH4)2HPO4.

[0051] According to a particular embodiment, the source of Na2O comprises or consists of Na2CO3, NaPO3, and / or NaNO3.

[0052] According to another aspect, the invention also relates to a glass capable of being obtained according to one of the methods defined above.

[0053] According to another aspect, the invention also relates to a powder consisting of or comprising glass particles as defined above.

[0054] According to a particular embodiment, the particles have a size of from 0.1 to 100 pm, in particular from 0.1 to 50 pm, notably from 1 to 50 pm.

[0055] According to a more particular embodiment, the particles have a size of 0.1 to 5 or even 2 μm.

[0056] All the embodiments described previously relating to the glass of the invention also apply here, alone or in combination.

[0057] According to another aspect, the invention also relates to a powder consisting of or comprising glass particles of the following formula (Io):

[0058] x Na2O - y NiO - (100-xy) P2O5 (Io),

[0059] with:

[0060] 0 < x <100

[0061] 10 < y < 100

[0062] x+y < 100. All the embodiments described previously relating to the glass of the invention also apply here, alone or in combination.

[0063] According to a particular embodiment, the powder as defined previously is free of KBr.

[0064] According to a particular embodiment, the particles have a size of 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.

[0065] According to a more particular embodiment, the particles have a size of 0.1 to 5 or even 2 μm.

[0066] By "size" is meant in particular the largest dimension of a particle.

[0067] This size is in particular an average size, as for example determined by laser granulometry.

[0068] According to another aspect, the invention also relates to a powder consisting of or comprising glass particles as defined above and an electronically conductive additive.

[0069] The electronically conductive additive, well known to those skilled in the art, may consist of or comprise hard carbon and / or graphite.

[0070] According to another aspect, the invention also relates to a powder consisting of or comprising glass particles as defined above and carbon particles.

[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 a particular embodiment, the particles have a size of from 0.1 to 100 pm, in particular from 0.1 to 50 pm, notably from 1 to 50 pm.

[0073] According to a more particular embodiment, the particles have a size of 0.1 to 5 or even 2 μm.

[0074] By "carbon particles" is meant particles constituting carbon black.

[0075] 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 spheroidal particles of 5 to 500 nm (largest dimension), in particular less than 100 nm.

[0076] According to another aspect, the invention also relates to a powder consisting of or comprising glass particles and an electronically conductive additive, in particular carbon particles, the glass being of the following formula (Io):

[0077] x Na2O - y NiO - (100-xy) P2O5 (Io),

[0078] with:

[0079] 0 < x <100

[0080] 10 < y < 100

[0081] x+y < 100. All the embodiments described previously relating to the glass and / or glass particles of the invention also apply here, alone or in combination.

[0082] According to a particular embodiment, the glass particles are mixed with particles of electronically conductive additive, in particular carbon, thus constituting a composite material. In this composite, the particles of electronically conductive additive, in particular carbon, are distributed in such a way that they envelop the glass particles.

[0083] 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.

[0084] According to another 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 96 / 2 to 90 / 5.

[0085] According to another aspect, the invention also relates to a powder consisting of or comprising glass particles as defined above, an electronically conductive additive, in particular carbon particles, and a binder.

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

[0087] According to another aspect, the invention also relates to a powder consisting of or comprising glass particles, an electronically conductive additive, in particular carbon particles, and a binder, the glass being of the following formula (Io):

[0088] x Na2O - y NiO - (100-xy) P2O5 (Io),

[0089] with:

[0090] 0 < x <100

[0091] 10 < y < 100

[0092] x+y < 100.

[0093] All embodiments described above relating to the glass and / or glass particles of the invention also apply here, alone or in combination.

[0094] According to a particular embodiment, the binder is a polymer, in particular polyvinylidene fluoride (PVDF).

[0095] According to a particular embodiment, the powder as defined previously comprises, by mass:

[0096] -from 50 to 90% of glass particles as defined above, in particular 70%;

[0097] -from 5 to 40% of carbon particles, in particular 25%; and

[0098] -from 5 to 10% of binder, in particular 5%.

[0099] According to a particular embodiment, the powder as defined previously comprises, by mass:

[0100] -from 90 to 96% of glass particles as defined previously;

[0101] -from 2 to 6% of carbon particles, in particular; and

[0102] -from 2 to 4% of binder.

[0103] According to another aspect, the invention also relates to a process for preparing a powder as defined above, comprising a step a) of grinding a glass as defined above.

[0104] All the embodiments described above relating to the 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 method of the invention as defined previously comprises: a. a first step of grinding, in particular using balls, of a glass as defined previously, to obtain a first glass powder; b. a second grinding step, in particular using balls, of a composition comprising the glass powder obtained from the previous grinding, as well as an electronically conductive additive powder, in particular carbon.

[0106] According to a more particular embodiment, the particles of the first glass powder have a size of 5 or even 10 to 20 μm.

[0107] The grinding according to a step a) as described above can in particular be carried out using a vibrating mill, or an attritor (erosion grinding). In the case of a vibrating mill, the glass is typically placed in a grinding tank containing one or more grinding balls. By means of oscillations of the grinding tank horizontally, the material is ground by impacts between the grinding balls, the tank and the material to be ground.

[0108] The ball milling according to a step b) as described previously can in particular be carried out using a planetary mill, or a centrifugal mill.

[0109] 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, in particular for a metal-ion battery or accumulator.

[0110] All the embodiments described above relating to the glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0111] According to another aspect, the invention also relates to the use of a glass or a glass powder for producing an electrode, in particular a positive one, in particular for a metal-ion battery or accumulator, the glass having the following formula (Io):

[0112] x Na2O - y NiO - (100-xy) P2O5 (Io),

[0113] with:

[0114] 0 <x<100

[0115] 10 < y < 100

[0116] x+y < 100.

[0117] All the embodiments described above relating to the glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0118] According to another aspect, the invention also relates to an electrode, in particular a positive electrode, in particular for a metal-ion battery or accumulator, comprising a glass as defined previously or a powder as defined previously.

[0119] All the embodiments described above relating to the glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0120] According to another aspect, the invention also relates to an electrode, in particular a positive electrode, in particular for a metal-ion battery or accumulator, comprising a glass or a glass powder, the glass of the following formula (Io):

[0121] x Na2O - y NiO - (100-xy) P2O5 (Io),

[0122] with:

[0123] 0 < x <100

[0124] 10 < y < 100

[0125] x+y < 100.

[0126] All the embodiments described above relating to the glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0127] According to another aspect, the invention also relates to a method for preparing an electrode, in particular a positive one, in particular for a metal-ion battery or accumulator, said method comprising a step A) of bringing into contact a powder consisting of or comprising glass particles, an electronically conductive additive, in particular carbon particles, and optionally a binder, as defined above, with a conductive support.

[0128] All the embodiments described above relating to the glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0129] According to a particular embodiment, the conductive support is a metal support, the metal being chosen in particular from Al, or Cu

[0130] According to a particular embodiment, the method of the invention as defined previously comprises:

[0131] Ao) a step of preparing an ink by adding a solvent, in particular chosen from N-methyl-2-pyrrolidone (NMP), or aqueous-based polymers (such as, for example, 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, dissolved beforehand 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;

[0132] A) a step A) of bringing a suspension as obtained at the end of step A) into contact with a conductive support, in particular by coating, for example of the “doctor blade” type to obtain a device;

[0133] B) optionally, a step of drying said device;

[0134] C) optionally a step of shaping, in particular by pelletizing, said device, optionally dried, in particular at a temperature of 50 to 100°C, in particular at approximately 60°C, and / or for 1 to 48 hours, for example for approximately 24 hours.

[0135] According to another aspect, the invention also relates to a battery or accumulator comprising an electrode, in particular a positive one, comprising a glass as defined previously or a powder as defined previously.

[0136] All the embodiments described above relating to the glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0137] According to another aspect, the invention also relates to a battery or accumulator comprising an electrode, in particular a positive one, comprising a glass or a glass powder, the glass being of the following formula (Io):

[0138] x Na2O - y NiO - (100-xy) P2O5 (Io),

[0139] with:

[0140] 0 < x <100

[0141] 10 < y < 100

[0142] x+y < 100.

[0143] All the embodiments described above relating to the glass and / or glass particles, and / or a powder of the invention also apply here, alone or in combination.

[0144] According to a particular embodiment, the battery or accumulator as defined previously further comprises at least one electrolyte, a separator, in particular microporous, and / or a negative electrode, in particular consisting of or comprising a metal chosen from Li, Na and K.

[0145] These elements are well known to those skilled in the art, who will be able to select them, in particular from commercial elements, according to requirements.

[0146] The negative electrode may also be made of or comprising hard carbon or graphite.

[0147] According to a particular embodiment, the positive electrode material of the battery or accumulator, as defined previously, has a theoretical specific capacity greater than 90 mAh / g, in particular greater than 120 mAh / g.

[0148] The batteries or accumulators of the invention can for example be used in the field of electrical storage, in particular stationary, or in electric mobility, in particular for portable or wearable electronics, in integration into fibers and / or cables, in particular in the context of wired batteries, or for medical use.

[0149] In particular, the batteries or accumulators of the invention can be used in the field of electric mobility, in particular for electric vehicles, rechargeable hybrid electric vehicles, hybrid vehicles, or electric 2-wheelers.

[0150] In particular, the batteries or accumulators of the invention can be used in the field of portable electrical equipment, in particular telephony, portable computers, or portable tools.

[0151] According to another aspect, the invention also relates to a battery comprising a cell or an accumulator as defined previously.

[0152] All the embodiments described previously relating to the 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.

[0153] According to another aspect, the invention also relates to an electric portable system or one adapted to electric mobility, comprising a battery as defined above.

[0154] All the embodiments described above relating to the 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

[0155] As used herein, the 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, as well as all other real numbers between these bounds. For example, "1-5", or "from 1 to 5" or "between 1 and 5" designates 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. For example, preferred values ​​for "1-5" might include the integers 1, 2, 3, 4, 5, 1-2, 1-3, 1-4, 1-5, 2-3, 2-4, 2-5, etc.

[0156] As used herein, the term "about" refers to a range of values ​​within ± 10% of a specific value. For example, the term "about 20" includes values ​​of 20 ± 10%, or values ​​from 18 to 22.

[0157] For the purposes of this description, percentages refer to percentages by mass relative to the total mass of the formulation, unless otherwise indicated. FIGURES

[0158] [Fig.l] shows a thermal cycle for producing glasses according to example 1.

[0159] [Fig.2] shows the first 3 galvanostatic cycles of 15 Na2O - 27 NiO - 58 P2O5 in Li-metal configuration. Cycling between 1.5V and 4.5V at C / 100, discharge start. Theoretical capacity used: 132 mAh / g. EXAMPLES

[0160] Example 1: Preparation of glasses 15 Na 2 O - 27 NiO - 58 P 2 O 5 and 24 Na 2 O -19 NiO - 57 P 2 O 5

[0161] The vitrified materials are produced by simple quenching of a cast iron bath (1400°C) by casting them respectively onto a metal plate.

[0162] The cast iron bath is obtained by subjecting a mixture of precursor powders (Na2CO3 for Na2O, NH4H2PO4 for P2O5 and NiO for NiO) to a specific heat treatment ([Fig.l]) allowing the elimination of unwanted chemical species (CO2, H2O and NH3), in particular between 150°C and 220°C for the moles of NH3 or at 800°C for 2 hours for the moles of CO2.

[0163] The targeted molar proportions are obtained by adequately weighing the different precursor powders constituting the mixture, according to the following reaction equation:

[0164] Na2CO3 + 2(NH4H2PO4) + NiO -> Na2O + [CO2] + [2 NH3 + 3 H2O] + P2O5 + NiO, before placing them in a Pt / Rh crucible.

[0165] The raw materials (without subsequent heat treatment such as stabilization annealing) are then analyzed to determine their amorphous character, their homogeneity as well as their actual chemical composition.

[0166] The amorphous nature of the materials was verified and confirmed by X-ray diffraction.

[0167] The elemental homogeneity of these glasses was confirmed by Scanning Electron Microscopy (SEM). For this, polished sections were made from the raw material.

[0168] The actual chemical composition of the glasses is obtained by X-ray fluorescence spectrometry (XRF). For this, glass beads are made by mixing 0.5g of the glass to be analyzed with 9.5g of lithium tetraborate and pouring the resulting glass (melted at 1200°C) onto a suitable support. The bead is then characterized by X-ray fluorescence by averaging 10 measurements. The results are presented in Table 1: XRF results (% elemental mass) and translation into % mol of oxides. Glass name %mass. Na %mass. P %mass. Ni 15 Na2O - 27 NiO - 58 P2O5 6.18 + 1.06 32.15 + 0.168 13.95 + 0.0964 24 Na2O - 19 NiO - 57 P2O5 10.2 + 0.803 32.11 + 0.168 10.33 + 0.112 Glass name %mol. Na 2 O %mol. P 2 O 5%mol. NiO 15 Na2O - 27 NiO - 58 P2O5 15.08 ± 0.08 58.15 + 0.21 26.77 + 0.08 24 Na2O - 19 NiO - 57 P2O5 24.21 ± 0.07 56.58 + 0.12 19.21 + 0.03

[0169] The glass is then ground for 3 min at 30 Hz using a vibrating mill (Retsch MM400) in order to be shaped into a button cell for electrochemical characterization.

[0170] Example 2: Electrochemical characterizations of 15 Na 2 O - 27 NiO -58 P 2 O 5 and 24 Na 2 O - 19 NiO - 57 P 2 O 5 glasses • Preparation of the electrodes#

[0171] Firstly, an intimate mixture of active material / carbon black (Super Carbon C65) in the mass proportions 70 / 25 was prepared using an energy mill (planetary mill PM 100) in the dry process. The grinding protocol lasts a total of 6 hours, at 300 rpm, alternating 5 minutes of grinding and 5 minutes of rest (in order to avoid local heating which could lead to potential devitrification / crystallization), i.e. 3 hours of effective grinding. Then, the powder obtained The grinding process is characterized by X-ray diffraction to ensure that the glass / carbon mixture is still amorphous.

[0172] The glass / carbon powder (i.e. composite material) obtained is then mixed with 5% by mass of polymer binder (solution of 10% by mass of Polyvinylidene Fluoride (PVDF) diluted in N-Methyl-2-Pyrrolidone (NMP). An additional solvent (NMP) is then added in order to obtain an ink of acceptable viscosity for coating. This ink, consisting of a dispersion of composite particles in PVDF and NMP, is mechanically stirred (for 15 minutes at 1000 rotations per minute) using a mechanical disperser (Dispermat). The latter makes it possible in particular to homogenize the dispersion and to disperse the composite aggregates formed during the grinding step. The ink is then coated by the “doctor blade” method (coating table with slit scraper set at 100 μm) on aluminum foil, then dried for 24 hours at 60°C in air to remove the residual solvent (NMP).

[0173] After drying, the electrode obtained is cut into 14 mm diameter discs, which are then pressed under a pressure of 10 tonnes. The mass of the pellets and their thicknesses were measured. The pellets are then dried under vacuum for 48 hours at 80°C in order to remove residual water. Finally, the electrodes are transferred to a glove box ([H2O] < «3 ppm, [O2] < Ippm), in order to be mounted in a button cell. • Production of button batteries#

[0174] The electrodes are mounted in a so-called half-button cell configuration (CR2032 type format), in a glove box, in a Li-metal or Na-metal or K-metal configuration. The electrodes are arranged in a cover, inside which an insulating seal 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 battery, only one separator, the Whatmann, was used. A volume of 150 pL of electrolyte is added to the propipette. Then, the counter-electrode, a metal foil (Li, Na or K) deposited on a stainless steel shim, is affixed above the separators. A spring is added to the counter-electrode, then the half-button cell is closed with a small cover and crimped.

[0175] 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%voi.:50%voi.) + 2%mass. of FEC K-metal: 0.7M of KPF6 in EC:DEC (50%voL:50%voi.) + 2%mass. of VC • Galvanostatic cycling#

[0176] The performance of the battery thus obtained is evaluated with an ARBIN type test bench. The batteries are typically cycled at the C / 100 rate, at room temperature, with a potential window between 1.5V and 4.5V. • Examples of galvanosatic cycling curves#

[0177] Figure 2 shows an example of galvanosatic cycling curves.

Claims

Claims

1. Glass of the following formula (I): x Na2O - y NiO - (100-xy) P2O5 (I), with: 0 <x<33, en particulier 0<x<25 ; 10<y<100 ; 40 < x+y < 100.

2. Glass according to claim 1, in which: - x < 32, with in particular x < 31, 30, 29, 28, 27, 26 or 25; and / or - 0.5 < 2x / y < 2.5 or 3.0; the glass being for example of a formula chosen from the following formulas: 15 Na2O - 27 NiO - 58 P2O5; or 24 Na2O - 19 NiO - 57 P2O5.

3. A method of 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, the source of Na2O and a source of P2O5, to obtain said glass.

4. A method according to claim 3, comprising: - a step (i) of quenching a molten mixture (A), which consists of or comprises a source of NiO, the source of Na2O 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 melted, 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 source of NiO comprises or consists of NiO, Ni2O3, and / or NiSO4; - the source of Na2O comprises or consists of Na2CO3, NaPO3, and / or NaNO3; and / or - the source of P2O5 comprises or consists 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, wherein the particles have in particular a size of from 0.1 to 100 pm, in particular from 0.1 to 50 pm.

7. Powder according to claim 6, further comprising and 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. Process for preparing an electrode, in particular a positive one, in particular for a metal-ion battery or accumulator, said process comprising a step A) of bringing into contact a powder consisting of or comprising glass particles, an electronically conductive additive, in particular carbon particles, and optionally a binder, according to one of claims 6 to 7, with a conductive support.

10. Battery or accumulator comprising an electrode, in particular positive, 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 90mAh / g.

11. A battery comprising a cell or accumulator according to claim 10.

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

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