Purification of black mass

Abstract

The disclosure provides a method for separating a black mass material into first and second constituent parts. The first constituent part comprises or consists of particles of a hydrophobic material and the second constituent part comprises or consists of particles of a hydrophilic material. The method comprises providing an emulsion. The emulsion comprises a first liquid phase dispersed as droplets in a second liquid phase, and the second liquid phase is or comprises water. The method further comprises contacting the emulsion with the black mass material to provide an emulsion-material mix and thereby allowing the particles of the hydrophobic material to be adsorbed into or onto the droplets of the first liquid phase, and the particles of the hydrophilic material to remain in the second liquid phase. The method further comprises separating the particles of the hydrophobic material and the particles of the hydrophilic material to thereby separate the first and second constituent parts of the black mass material. 15

Description

[0001] Purification of Black Mass

[0002] The present invention relates to a method of separating constituent parts of black mass.

[0003] With the application of lithium-ion batteries (LiBs) in electrical vehicles, the recycling of spent LiBs is becoming increasingly important in order to keep the industry healthy and sustainable. LiBs are generally made of stacked anode and cathode thin films. Once spent, these are commonly crushed and shredded into small pieces. The inactive parts, including copper, aluminium and polymer separator, are then separated out by techniques such as sieving, winnowing and magnetic separation. This leaves the active parts, including graphite and lithium metal oxides, as so-called "black mass". Further treatment of black mass with pyrometallurgy and / or hydrometallurgical processes is usually necessary to extract valuable metal materials. These processes generally dissolve the lithium metal oxide or burn the graphite.

[0004] 'Closed-loop' battery recycling processes are desirable. These aim to recycle every component of a battery without destruction of the recycled materials' crystal structures. This means the recycled materials can be directly reused in battery fabrication. These processes also aim to reduce the consumption of energy and harmful chemicals, further improving the sustainability of battery recycling.

[0005] A froth floatation method has been developed to selectively separate graphite and lithium metal oxide. The method uses froth as a transferring vehicle, based on surface wettability of different mineral particles. This process uses expensive chemicals (frother and collector), takes a long time to complete, and generates low yields and purities (85 to 95%, [S. D. Barma et al. (2019) Ultrasonic-assisted flotation for enhancing the recovery of flaky graphite from low-grade graphite ore]). This process also suffers from the problems of entrainment and entrapment, which reduce the purity of the mineral products.

[0006] The present invention arose from the inventors' work in attempting to address the problems associated with the prior art.

[0007] In accordance with a first aspect of the invention, there is provided a method for separating a black mass material into first and second constituent parts, wherein the first constituent part comprises or consists of particles of a hydrophobic material and the second constituent part comprises or consists of particles of a hydrophilic material, the method comprising: providing an emulsion, the emulsion comprising a first liquid phase dispersed as droplets in a second liquid phase, wherein the second liquid phase is or comprises water; contacting the emulsion with the black mass material to provide an emulsionmaterial mix and thereby allowing the particles of the hydrophobic material to be adsorbed into or onto the droplets of the first liquid phase, and the particles of the hydrophilic material to remain in the second liquid phase; and

[0008] - separating the particles of the hydrophobic material and the particles of the hydrophilic material to thereby separate the first and second constituent parts of the black mass material.

[0009] Advantageously, particles of a hydrophobic material are not stable in the second liquid phase, due to the second liquid phase being or comprising water. However, droplets of the first liquid phase form on the hydrophobic material or encompass the hydrophobic material therein or thereon, depending on the size of the droplets. Over time, particles of the hydrophobic material will collide and aggregate, forming an aggregate in a droplet of the first liquid phase.

[0010] Conversely, the particles of the hydrophilic material will be stable in the second liquid phase. Since they are hydrophilic, droplets of the second liquid phase will not absorb thereon and the particles of the hydrophilic material are not absorbed into or onto droplets of the first liquid phase. Instead, the particles of the hydrophilic material will remain dispersed in the second liquid phase and / or form sediment at the bottom thereof. The particles of the hydrophilic material may not form aggregates.

[0011] Separating the particles of the hydrophobic material and the particles of the hydrophilic material may comprise recovering one or more aggregates, wherein the or each aggregate comprises or consists of a plurality of particles of the hydrophobic material. Accordingly, the first constituent part may comprise or consist of one or more aggregates.

[0012] The or each aggregate may comprise less than 15 vol%, less than 12 vol%, less than 10 vol%, less than 9 vol%, less than 8 vol%, less than 7 vol%, less than 6 vol%, less than 5 vol%, less than 4 vol%, less than 3 vol% or less than 2 vol% of the hydrophilic material. In some embodiments the or each aggregate may be substantially free of particles of the hydrophilic material. Separating the particles of the hydrophobic material and the particles of the hydrophilic material may comprise sieving the emulsion-material mix. Sieving the emulsion-material mix may comprise passing the emulsion-material mix through a sieve. Advantageously, the sieve aperture size may be selected such that the aggregates are retained in the sieve and the particles of the hydrophilic material pass through the sieve. It may be understood that the emulsion may also pass through the sieve.

[0013] The method may comprise washing material retained in the sieve. The material may be washed with water. Washing the material may cause particles of hydrophilic material retained in the sieve to pass therethrough.

[0014] The sieve may have an aperture size between 50 pm and 1 mm, between 75 and 900 pm, between 100 and 800 pm, between 200 and 700 pm, between 300 and 650 pm, between 400 and 600 pm, between 450 and 550 pm, between 475 and 525 pm, or between 490 and 510 pm.

[0015] Liquid and / or suspensions which have passed through the sieve may be called filtrates. It may be appreciated that in methods where the method comprises washing material retained in the sieve, the method may generate multiple filtrates. In these embodiments, the method may comprise combining the filtrates to provide a single combined filtrate. Accordingly, the filtrate may comprise the emulsion and the hydrophilic particles. The filtrate may further comprise the liquid used to wash the material retained in the sieve.

[0016] The method may comprise separating the particles of the hydrophilic material and the emulsion. Accordingly, the method may comprise filtering and / or sieving the filtrate. The method may comprise filtering and / or sieving each filtrate which is obtained. Alternatively, the method may comprise filtering and / or sieving the combined filtrate. Filtering and / or sieving the filtrate may comprise passing the filtrate through a filter or sieve. Advantageously, the sieve aperture size may be selected such that the particles of the hydrophilic material are retained in the sieve and the emulsion passes through the sieve.

[0017] The filter or sieve may have an aperture size of less than 20 pm, less than 10 pm, less than 5 pm, less than 2 pm or less than 1 pm. The method may further comprise washing the particles of the hydrophilic material subsequent to filtering and / or sieving them. The particles of the hydrophilic material may be washed with water.

[0018] The emulsion and the black mass material may be contacted in a ratio of between 1 and 1000 mL of emulsion per 1 g black mass, between 10 and 100 mL of emulsion per 1 g black mass, between 15 and 50 mL of emulsion per 1 g black mass, between 20 and 40 mL of emulsion per 1 g black mass, between 25 and 35 mL of emulsion per 1 g black mass or between 28 and 32 mL of emulsion per 1 g black mass.

[0019] Advantageously the method may yield the first and / or second constituent part of the black mass with a high purity.

[0020] The first constituent part obtained from the method may comprise the particles of the hydrophobic material with a purity of at least 50 vol%, at least 60 vol%, at least 70 vol%, at least 80 vol%, at least 90 vol%, at least 92 vol%, at least 95 vol%, at least 97 vol%, at least 98 vol% or at least 98 vol%. The first constituent part obtained from the method may comprise less than 15 vol%, less than 12 vol%, less than 10 vol%, less than 9 vol%, less than 8 vol%, less than 7 vol%, less than 6 vol%, less than 5 vol%, less than 4 vol%, less than 3 vol% or less than 2 vol% of the hydrophilic material.

[0021] The second constituent part obtained from the method may comprise the particles of the hydrophilic material with a purity of at least 50 vol%, at least 60 vol%, at least 70 vol%, at least 80 vol%, at least 90 vol%, at least 92 vol%, at least 95 vol%, at least 97 vol%, at least 98 vol% or at least 98 vol%. The second constituent part obtained from the method may comprise less than 15 vol%, less than 12 vol%, less than 10 vol%, less than 9 vol%, less than 8 vol%, less than 7 vol%, less than 6 vol%, less than 5 vol%, less than 4 vol%, less than 3 vol% or less than 2 vol% of the hydrophobic material.

[0022] In order to increase the purity of the obtained first and / or second constituent part of the black mass, the method may comprise repeating the separation process, using the previously obtained first constituent part or second constituent part of the black mass material.

[0023] Repeating the separation process may comprise: - contacting the emulsion with the previously obtained first constituent part of the black mass material to provide an emulsion-material mix and thereby allowing the particles of the hydrophobic material to be adsorbed into or onto the droplets of the first liquid phase, and particles of the hydrophilic material present in the previously obtained first constituent part of the black mass material to remain in the second liquid phase; and

[0024] - separating the particles of the hydrophobic material and the particles of the hydrophilic material to thereby obtain a purified first constituent part of the black mass material.

[0025] Any particles of the hydrophilic material obtained in the above process may be combined with the second constituent part of the black mass material.

[0026] Alternatively or additionally, repeating the separation process may comprise:

[0027] - contacting the emulsion with the previously obtained second constituent part of the black mass material to provide an emulsion-material mix and thereby allowing the particles of the hydrophobic material present in the previously obtained second constituent part of the black mass material to be adsorbed into or onto the droplets of the first liquid phase, and particles of the hydrophilic material present to remain in the second liquid phase; and

[0028] - separating the particles of the hydrophobic material and the particles of the hydrophilic material to thereby obtain a purified second constituent part of the black mass material.

[0029] Any particles of the hydrophobic material obtained in the above process may be combined with the first constituent part of the black mass material.

[0030] In some embodiments the emulsion is stable for at least an hour, at least 6 hours, at least 12 hours at least 24 hours, at least 2 days, at least 4 days, at least 1 week or at least two weeks.

[0031] The emulsion may comprise the first liquid phase in an amount of between 0.01 v / v% and 10 v / v%, between 0.1 v / v% and 5.0 v / v%, between 0.2 and 2.5 v / v%, between 0.3 and 2.0 v / v%, between 0.4 and 1.75 v / v%, between 0.5 and 1.5 v / v%, between 0.6 and 1.4 v / v%, between, 0.7 and 1.3 v / v%, between 0.8 and 1.2 v / v%, between 0.9 and 1.1 v / v% or between 0.95 and 1.05 v / v%. The emulsion may comprise the second liquid phase in an amount of between 90 v / v% and 99.9 v / v%, between 95.0 v / v% and 99.9 v / v%, between 96.0 and 99.8 v / v%, between 97.0 and 99.7 v / v%, between 98.0 and 99.6 v / v%, between 98.25 and 99.5 v / v%, between 98.5 and 99.4 v / v%, between, 98.7 and 99.3 v / v%, between 98.8 and 99.2 v / v%, between 98.9 and 99.1 v / v% or between 98.95 and 99.05 v / v%.

[0032] In some embodiments, the emulsion is emulsifier-free. In some embodiments, the emulsion is surfactant free. Accordingly, in an embodiment, the method does not use any surfactants or emulsifiers.

[0033] The inventors note that an emulsifier can modify the surface of graphite from hydrophobic to hydrophilic. Accordingly, inclusion of an emulsifier could have a detrimental effect on the method.

[0034] Accordingly, it will be appreciated that the first liquid phase is substantially water- immiscible. Accordingly, the first liquid phase may comprise or consist of one or more non-polar, substantially water-immiscible components. The or each non-polar substantially water-immiscible component may be a hydrocarbon. The or each hydrocarbon may be substituted or unsubstituted. The or each hydrocarbon may independently be aliphatic or aromatic.

[0035] The or each hydrocarbon may be an optionally substituted alkane, an optionally substituted alkene, an optionally substituted cycloalkane, an optionally substituted triglyceride or an optionally substituted aromatic hydrocarbon. It may be appreciated that an alkane or alkene group could be unsubstituted or substituted with one or more substituents, each substituent being independently selected from OH and COOH. It may be appreciated that an alkane or alkene substituted with an COOH may be a fatty acid. It may be appreciated that a cycloalkyl or aromatic hydrocarbon could be unsubstituted or substituted with one or more substituents, each substituent being independently selected from an alkane, an alkene, OH and COOH. The or each triglyceride and / or fatty acid may be saturated and / or unsaturated. If the triglyceride and / or fatty acid is unsaturated it may be monounsaturated or polyunsatutated.

[0036] It may be appreciated that the first liquid phase may comprise or consist of an oil. The emulsion may be an oil-in-water emulsion.

[0037] In some embodiments, the or each hydrocarbon comprises between 1 and 50 carbon atoms per molecule, between 5 and 40 carbon atoms per molecule, between 6 and 30 carbon atoms per molecule, between 7 and 25 carbon atoms per molecule, between 8 and 20 carbon atoms per molecule, between 9 and 18 carbon atoms per molecule, or between 10 and 16 carbon atoms per molecule.

[0038] It may be appreciated that a triglyceride contains three fatty acid groups. In some embodiments, the triglyceride contains three fatty acid groups, where each fatty acid group comprises between 1 and 50 carbon atoms per molecule, between 5 and 40 carbon atoms per molecule, between 6 and 30 carbon atoms per molecule, between 7 and 25 carbon atoms per molecule, between 12 and 22 carbon atoms per molecule, between 9 and 18 carbon atoms per molecule, or between 16 and 18 carbon atoms per molecule.

[0039] The first liquid phase may comprise or consist of kerosene. It may be appreciated that kerosene is composed of hydrocarbon molecules that typically contain between 6- 20 carbon atoms per molecule, predominantly containing 9 to 16 carbon atoms. Furthermore, kerosene's major components (normally at least 70 vol%) are branched and straight-chain alkanes and cycloalkanes. Kerosene also contains aromatic hydrocarbons (normally less than 25 vol%) and alkanes (normally less than 5 vol%).

[0040] The first liquid phase may comprise or consist of vegetable oil. Vegetable oils are composed of triglyceride molecules. However, it may be appreciated that the composition of vegetable oil will vary depending on the type of oil. In vegetable oils the fatty acids which form the triglycerides typically contain 12 to 22 carbons, with fatty acids with 16 to 18 hydrocarbons being the most common. The fatty acids typically comprise a mix of saturated, monounsaturated and polysaturated fatty acids.

[0041] The first liquid phase may have a density which is less than the density of the second liquid phase.

[0042] The first liquid phase may have a density of less than 1 g / cm3. The first liquid phase may have a density of less than 0.98 g / cm3, less than 0.96 g / cm3, less than 0.94 g / cm3, or less than 0.93 g / cm3. In some embodiments, the first liquid phase may have a density of less than 0.92 g / cm3, less than 0.90 g / cm3, less than 0.88 g / cm3, less than 0.86 g / cm3, less than 0.84 g / cm3or less than 0.82 g / cm3.

[0043] The first liquid phase may have a density of at least 0.6 g / cm3, at least 0.7 g / cm3, at least 0.72 g / cm3, at least 0.74 g / cm3, at least 0.76 g / cm3or at least 0.78 g / cm3. In some embodiments, the first liquid phase may have a density of at least 0.80 g / cm3, at least 0.82 g / cm3, at least 0.84 g / cm3, at least 0.86 g / cm3, at least 0.88 g / cm3or at least 0.90 g / cm3.

[0044] The first liquid phase may have a density of between 0.60 and 0.98 g / cm3, between 0.70 and 0.97 g / cm3, between 0.72 and 0.96 g / cm3, between 0.74 and 0.95 g / cm3, between 0.76 and 0.94 g / cm3or between 0.78 and 0.93 g / cm3. In some embodiments, the first liquid phase may have a density of between 0.80 and 0.96 g / cm3, between 0.85 and 0.95 g / cm3, between 0.90 and 0.94 g / cm3or between 0.91 and 0.93 g / cm3. In some embodiments, the first liquid phase may have a density of between 0.7 and 0.9 g / cm3, between 0.75 and 0.85 g / cm3, between 0.76 and 0.84 g / cm3, between 0.77 and 0.83 g / cm3, between 0.78 and 0.82 g / cm3or between 0.79 and 0.81 g / cm3.

[0045] For the avoidance of doubt, all density measurements defined herein are taken at 20 °C unless otherwise specified.

[0046] It may be appreciated that the second liquid phase is water-miscible. Accordingly, the second liquid phase may consist or comprise of one or more polar, water-miscible components. The second liquid phase may comprise water. The second liquid phase may consist substantially of or consist of water. The water may be deionised water.

[0047] The second liquid phase may have a density of at least 0.9 g / cm3, at least 0.92 g / cm3, at least 0.94 g / cm3, at least 0.96 g / cm3, at least 0.98 g / cm3, at least 0.99 g / cm3, at least 0.995 g / cm3or at least 0.998 g / cm3. The second liquid phase may have a density of less than 1.15 g / cm3, less than 1.1 g / cm3, less than 1.08 g / cm3, less than 1.06 g / cm3, less than 1.04 g / cm3, less than 1.02 g / cm3, less than 1.01 g / cm3or less than 1.00 g / cm3. The second liquid phase may have a density of between 0.9 and 1.15 g / cm3, between 0.92 and 1.1 g / cm3, between 0.94 and 1.08 g / cm3, between 0.96 and 1.06 g / cm3, between 0.98 and 1.04 g / cm3, between 0.99 and 1.02 g / cm3, between 0.995 and 1.01 g / cm3, or between 0.998 and 1.00 g / cm3.

[0048] In some embodiments, the difference in density between the first liquid phase and the second liquid phase is less than 0.25 g / cm3, less than 0.22 g / cm3, less than 0.20 g / cm3, less than 0.19 g / cm3, less than 0.18 g / cm3, less than 0.15 g / cm3, less than 0.12 g / cm3, less than 0.10 g / cm3, less than 0.09 g / cm3or less than 0.08 g / cm3.

[0049] In some embodiments, the first liquid phase has a density which is different to the density of the second liquid phase by less than 30%, less than 25% or less than 20%. In some embodiments, the first liquid phase has a density which is different to the density of the second liquid phase by less than 15% or less than 10%.

[0050] Advantageously, the inventors have found that the lesser the difference in density between the first liquid phase and the second liquid phase, the more stable the emulsion.

[0051] The droplets of the first liquid phase in the emulsion may have an average diameter of less than 700 nm, less than 600 nm, less than 500 nm or less than 450 nm. In some embodiments, the droplets of the first liquid phase in the emulsion may have an average diameter of less than 400 nm, less than 350 nm, less than 300 nm, less than 250 nm or less than 225 nm.

[0052] Droplets of the first liquid phase in the emulsion may have an average diameter of between 50 and 700 nm, between 100 and 600 nm, between 130 and 500 nm or between 150 and 450 nm. In some embodiments, droplets of the first liquid phase in the emulsion have an average diameter of between 100 and 400 nm, between 150 and 300 nm, between 160 and 250 nm, between 170 and 240 nm, between 180 and 230 nm, between 190 and 220 nm, or between 200 and 210 nm. In an alternative embodiment, droplets of the first liquid phase in the emulsion have an average diameter of between 200 and 600 nm, between 250 and 550 nm, between 300 and 500 nm, between 350 and 450 nm, between 370 and 420 nm, between 380 and 410 nm, or between 390 and 400 nm.

[0053] Advantageously, the inventors have found that the smaller the droplets of the first liquid phase in the second liquid phase, the more stable the emulsion.

[0054] The average diameter may be the median diameter. The average diameter may be the mean diameter. The average diameter may be the modal diameter. It is noted that the median, mean and modal diameter are similar. It may be appreciated that the average diameter of the droplets of the first liquid phase may be determined using dynamic light scattering (DLS).

[0055] Providing the emulsion may comprise agitating a precursor mixture, wherein the precursor mixture comprises the first liquid phase and the second liquid phase, thereby causing the first liquid phase to form droplets in the second liquid phase. The amount of the first liquid phase in the precursor mixture may be the same as the amount of the first liquid phase in the emulsion, as defined above. The amount of the second liquid phase in the precursor mixture may be the same as the amount of the second liquid phase in the emulsion, as defined above.

[0056] The method may comprise combining the first liquid phase and the second liquid phase to provide the precursor mixture.

[0057] The precursor mixture may be a precursor emulsion comprising the first liquid phase dispersed as droplets in the second liquid phase. Advantageously, in embodiments where the precursor mixture is a precursor emulsion, applying a mechanical force to the precursor mixture reduces the average diameter of the droplets of the first liquid phase and provides the emulsion.

[0058] Alternatively, the precursor mixture may comprise the first and second liquid phases as distinct separated phases. Advantageously, in embodiments where the precursor mixture comprises the first and second liquid phases as distinct separated phases, applying a mechanical force to the precursor mixture provides the emulsion.

[0059] Agitating the precursor mixture may comprise applying a mechanical force to the precursor mixture. The mechanical force may be an ultrasonic wave or a shear force. Accordingly, agitating the precursor mixture may comprise ultrasonicating the precursor mixture. Alternatively, agitating the precursor mixture may comprise treating the precursor mixture using a high-shear in-line mixer or a colloid mill.

[0060] The precursor may be ultrasonicated using an ultrasonic horn. It may be appreciated that an ultrasonic horn may also be known as an acoustic horn, a sonotrode, an acoustic waveguide or an ultrasonic probe. The ultrasonic horn may be a cylindrical horn or a circular horn. The ultrasonic horn may have a diameter of at least 1 mm, at least 5 mm, at least 10 mm, at least 12.5 mm, at least 15 mm or at least 17.5 mm. The ultrasonic horn may have a diameter of less than 500 mm, less than 100 mm, less than 50 mm, less than 30 mm, less than 25 mm or less than 22.5 mm. The ultrasonic horn may have a diameter of between 1 and 500 mm, between 5 and 100 mm, between 10 and 50 mm, between 12.5 and 30 mm, between 15 and 25 mm or between 17.5 and 22.5 mm.

[0061] The precursor mixture may be ultrasonicated at a power of at least 10 watts, at least 50 watts, at least 100 watts, at least 200 watts, at least 300 watts, at least 400 watts, at least 450 watts or at least 490 watts. The precursor mixture may be ultrasonicated at a power of less than 5,000 watts, less than 2,000 watts, less than 1,500 watts, less than 1,000 watts, less than 800 watts, less than 600 watts, less than 550 watts or less than 510 watts. The precursor mixture may be ultrasonicated at a power of between 10 and 5,000 watts, 50 and 2,000 watts, between 100 and 1,500 watts, between 200 and 1,000 watts, between 300 and 800 watts, between 400 and 600 watts, between 450 and 550 watts, or between 490 and 510 watts.

[0062] The precursor mixture may be agitated for at least 10 seconds, at least 20 seconds, at least 30 seconds, at least 40 seconds, at least 50 seconds or at least 55 seconds. The precursor mixture may be agitated for between 10 seconds and 1 hour, between 20 seconds and 30 minutes, between 30 seconds and 10 minutes, between 40 seconds and 5 minutes, between 50 seconds and 2 minutes, or between 55 seconds and 65 seconds.

[0063] The method may comprise contacting the black mass material and the precursor mixture. Accordingly, providing the emulsion (e.g. by agitating a precursor mixture) may inherently cause the emulsion to contact the black mass material.

[0064] In an alternative embodiment, the method comprises providing the emulsion and subsequently contacting the emulsion and the black mass material.

[0065] It may be appreciated that the term "black mass" as used herein, may refer to a composition comprising or consisting of electrode materials, the electrode materials originating from lithium-ion batteries or lithium-ion battery production. The electrode materials may be shredded. The black mass may be free of or substantially free of inactive battery materials, such as casing or cabling. The black mass material may originate from new lithium-ion batteries, waste lithium-ion batteries, spent lithium-ion batteries, lithium-ion battery production waste or scrap materials and lithium-ion battery electrode materials.

[0066] The black mass material may comprise particles of the hydrophobic material. The black mass material may comprise particles of more than one hydrophobic material. The or each hydrophobic material may be an anode material. It may be appreciated that an "anode material" as used herein, refers to a material originating from a lithium-ion battery anode or to a material originating from the production of a lithium ion battery anode.

[0067] The or each hydrophobic material may comprise or consist of carbon. The hydrophobic material may comprise or be graphite. The particles of the hydrophobic material may have a diameter of between 1 and 100 pm, between 2 and 80 pm, between 3 and 70 pm, between 4 and 60 pm, between 5 and 50 pm , between 6 and 40 pm, between 7 and 30 pm, between 8 and 25 pm, between 9 and 21 pm, or between 10 and 20 pm. The diameter may be understood to be the mean diameter. It may be appreciated that the diameter may be measured using a scanning electron microscope.

[0068] The black mass material may comprise particles of the hydrophilic material. The black mass material may comprise particles of more than one hydrophilic material. The or each hydrophilic material may be a cathode material. It may be appreciated that a "cathode material" as used herein, refers to a material originating from a lithium-ion battery cathode or to a material originating from the production of a lithium-ion battery cathode.

[0069] The particles of the hydrophilic material may have a diameter of between 1 and 100 pm, between 2 and 80 pm, between 3 and 70 pm, between 4 and 60 pm, between 5 and 50 pm, between 6 and 40 pm, between 7 and 30 pm, between 8 and 25 pm, between 9 and 21 pm, or between 10 and 20 pm. The diameter may be understood to be the mean diameter. It may be appreciated that the diameter may be measured using a scanning electron microscope.

[0070] The or each hydrophilic material may be or comprise a metal containing compound. The metal containing compound may contain one or more metals.

[0071] The or each hydrophilic material may comprise lithium, manganese, nickel, cobalt, aluminium and / or iron.

[0072] The hydrophilic material may comprise oxygen and / or phosphorus. Accordingly, the hydrophilic material may be or comprise an oxide and / or a phosphate. The hydrophilic material may be or comprise a metal oxide.

[0073] In some embodiments, the hydrophilic material comprises lithium and oxygen. In some embodiments, the hydrophilic material may further comprise manganese, nickel and / or cobalt. The or each hydrophilic material may comprise or be a lithium nickel manganese cobalt oxide (NMC) compound. The hydrophilic material may comprise or be a compound of formula (I):

[0074] LiNixMriyCOzC (I)

[0075] , wherein 0 < x < 1, 0 < y < 1, and 0 < z < 1; and wherein the sum of x, y and z is equal to 1.

[0076] In some embodiments, in formula (I) x is 0.6, y is 0.2 and z is 0.2. In some embodiments, in formula (I) x is 0.8, y is 0.1 and z is 0.1. In some embodiments, in formula (I) x is 0.5, y is 0.3 and z is 0.2.

[0077] In some embodiments, the hydrophilic material comprises lithium and oxygen. In some embodiments, the hydrophilic material may further comprise cobalt. The or each hydrophilic material may comprise or be a lithium cobalt oxide (LCO) compound. The hydrophilic material may comprise or be a compound of formula (II):

[0078] LixCoO2(II)

[0079] , wherein 0 < x < 1.

[0080] In some embodiments, in formula (II) x is 1.

[0081] In some embodiments, the hydrophilic material comprises lithium and oxygen. In some embodiments, the hydrophilic material may further comprise manganese. The or each hydrophilic material may comprise or be a lithium manganese oxide (LMO) compound. Accordingly, the hydrophilic material may comprise or be LiMnC , LizMnCh, Li2MnO2or LiMn2O4.

[0082] In some embodiments, the hydrophilic material comprises lithium and oxygen. In some embodiments, the hydrophilic material may further comprise nickel, cobalt and / or aluminium. Accordingly, the or each hydrophilic material may comprise or be a lithium nickel cobalt aluminium oxide (NCA) compound. The hydrophilic material may comprise or be a compound of formula (III):

[0083] LiNixCoyAlzO2

[0084] (HI)

[0085] , wherein 0 < x < 1, 0 < y < 1, and 0 < z < 1; and wherein the sum of x, y and z is equal to 1.

[0086] In some embodiments, in formula (III) x is 0.8, y is 0.15 and z is 0.05. In some embodiments, the hydrophilic material comprises lithium and oxygen. In some embodiments, the hydrophilic material may further comprise iron. In some embodiments, the hydrophilic material may further comprise phosphorous.

[0087] Accordingly, the or each hydrophilic material may comprise or be a lithium iron phosphate (LFP) compound. The LFP compound may be LiFePC .

[0088] It may be appreciated that the term agglomerate as used herein, refers to a mass of particles. The black mass material may comprise or consist of an agglomerate. The black mass material may comprise or consist of a plurality of agglomerates. The plurality of agglomerates may comprise one or more agglomerates which comprise particles of the hydrophobic material and particles of the hydrophilic material.

[0089] The method may comprise breaking up the agglomerate or the plurality of agglomerates of black mass material. Advantageously, breaking up the agglomerates separates particles of the hydrophilic material from particles of the hydrophobic material. This better enable particles of the hydrophobic material to be adsorbed into or onto the droplets of the first liquid phase and aids the separation process.

[0090] The method may comprise: breaking up an agglomerate or a plurality of agglomerates of a black mass material; providing an emulsion, the emulsion comprising a first liquid phase dispersed as droplets in a second liquid phase, wherein the second liquid phase is or comprises water; contacting the emulsion with the black mass material to provide an emulsionmaterial mix and thereby allowing the particles of the hydrophobic material to be adsorbed into or onto the droplets of the first liquid phase, and the particles of the hydrophilic material to remain in the second liquid phase; and

[0091] - separating the particles of the hydrophobic material and the particles of the hydrophilic material to thereby separate the first and second constituent parts of the black mass material.

[0092] Breaking up the agglomerate or the plurality of agglomerates of the black mass material may be conducted by agitating the black mass material and / or applying a mechanical force thereto. The mechanical force may be an ultrasonic wave. The black mass material may be ultrasonicated using an ultrasonic horn. The ultrasonic horn may be as defined above. Breaking up the agglomerate or the plurality of agglomerates of the black mass material may be conducted prior to contacting the emulsion with the black mass material. Alternatively, breaking up the agglomerate or the plurality of agglomerates of the black mass material may be conducted simultaneously or subsequently to contacting the emulsion with the black mass material.

[0093] Accordingly, the method may comprise agitating the emulsion-material mix. The method may comprise: providing an emulsion, the emulsion comprising a first liquid phase dispersed as droplets in a second liquid phase, wherein the second liquid phase is or comprises water; contacting the emulsion with the black mass material to provide an emulsionmaterial mix; agitating the emulsion-material mix and thereby breaking up an agglomerate or a plurality of agglomerates of the black mass material and allowing the particles of the hydrophobic material to be adsorbed into or onto the droplets of the first liquid phase, and the particles of the hydrophilic material to remain in the second liquid phase; and

[0094] - separating the particles of the hydrophobic material and the particles of the hydrophilic material to thereby separate the first and second constituent parts of the black mass material.

[0095] Agitating the emulsion-material mix may comprise applying a mechanical force to the emulsion-material mix. The mechanical force may be an ultrasonic wave. Accordingly, agitating the emulsion-material mix may comprise ultrasonicating the emulsionmaterial mix. The emulsion-material mix may be ultrasonicated using an ultrasonic horn. The ultrasonic horn may be as defined above.

[0096] The emulsion-material may be ultrasonicated at a power of at least 10 watts, at least 50 watts, at least 100 watts, at least 200 watts, at least 300 watts, at least 400 watts, at least 450 watts or at least 490 watts. The emulsion-material may be ultrasonicated at a power of less than 5,000 watts, less than 2,000 watts, less than 1,500 watts, less than 1,000 watts, less than 800 watts, less than 600 watts, less than 550 watts or less than 510 watts. The emulsion-material may be ultrasonicated at a power of between 10 and 5,000 watts, 50 and 2,000 watts, between 100 and 1,500 watts, between 200 and 1,000 watts, between 300 and 800 watts, between 400 and 600 watts, between 450 and 550 watts, or between 490 and 510 watts. The emulsion-material may be agitated for at least 10 seconds, at least 20 seconds, at least 30 seconds, at least 40 seconds, at least 50 seconds or at least 55 seconds. The emulsion-material may be agitated for between 10 seconds and 1 hour, between 20 seconds and 30 minutes, between 30 seconds and 10 minutes, between 40 seconds and 5 minutes, between 50 seconds and 2 minutes, or between 55 seconds and 65 seconds.

[0097] The black mass material may be binder free. Alternatively, the black mass material may comprise a polymer binder. The black mass material may comprise more than one polymer binder. It may be appreciated that the particles of the hydrophilic and / or hydrophobic material may be coated in a polymer binder.

[0098] The polymer binder may comprise or be a hydrophobic polymer binder. For example, the hydrophobic polymer binder may comprise or consist of polyvinylidene difluoride (PVDF).

[0099] The polymer binder may comprise or be a hydrophilic polymer binder. For example, the hydrophilic polymer binder may comprise or consist of styrene-butadiene rubber (SBR) and / or sodium carboxymethyl cellulose (CMC). The hydrophilic polymer binder may comprise or consist of sodium alginate.

[0100] One or more particles of the hydrophobic material may be coated with the hydrophilic polymer binder. One or more particles of the hydrophilic material may be coated with the hydrophobic polymer binder.

[0101] In some embodiments, the method comprises a step of removing the polymer binder from the black mass material to provide a binderless black mass material. The polymer binder may be removed prior to contacting the emulsion with the black mass material. The binderless black mass material may be understood to be substantially binder free.

[0102] The black mass material may be understood to be substantially binder free if more than 80 wt%, more than 85 wt%, more than 90 wt%, more than 93 wt%, more than 94 wt%, more than 95 wt%, more than 96 wt%, more than 97 wt%, more than 98 wt% or more than 99 wt% of the polymer binder has been removed from the black mass material.

[0103] The method may comprise: removing a polymer binder from the black mass material to provide a binderless black mass material; providing an emulsion, the emulsion comprising a first liquid phase dispersed as droplets in a second liquid phase, wherein the second liquid phase is or comprises water; contacting the emulsion with the binderless black mass material to provide an emulsion-material mix and allowing the particles of the hydrophobic material to be adsorbed into or onto the droplets of the first liquid phase, and the particles of the hydrophilic material to remain in the second liquid phase; and

[0104] - separating the particles of the hydrophobic material and the particles of the hydrophilic material to thereby separate the first and second constituent parts of the black mass material.

[0105] Removing the polymer binder may comprise removing the hydrophilic polymer binder. Removing the polymer binder may comprise removing the hydrophobic polymer binder. In an embodiment, removing the polymer binder may comprise removing the hydrophilic polymer binder and removing the hydrophobic polymer binder. The hydrophilic polymer binder may be removed before, at the same time or after the hydrophobic polymer binder. In some embodiments, the hydrophilic polymer binder is removed before the hydrophobic polymer binder.

[0106] Removing the hydrophilic polymer binder from the black mass material may comprise rinsing the black mass material with a solvent. The solvent may be water.

[0107] Removing the hydrophobic polymer binder from the black mass material may comprise heating the black mass material. The black mass material may be heated to a temperature of at least 100°C, at least 200°C, at least 250°C, at least 300°C, at least 350°C, at least 400°C, at least 450°C or at least 500°C. The black mass material may be heated to a temperature of between 100°C and 2000°C, between 200°C and 1000°C, between 300°C and 700°C, between 400°C and 600°C or between 450°C and 550°C.

[0108] Removing the hydrophobic polymer binder from the black mass material may comprise heating the black mass material for at least 1 minute, at least 5 minutes, at least 10 minutes, at least 20 minutes, at least 30 minutes, at least 40 minutes or at least 60 minutes. Removing the hydrophobic polymer binder from the black mass material may comprise heating the black mass material for between 1 minute and 12 hours, between 5 minutes and 6 hours, between 10 and 60 minutes, between 15 and 45 minutes, between 20 and 40 minutes or between 25 and 35 minutes. Removing the hydrophobic polymer binder from the black mass material may comprise heating the black mass material for between 1 minute and 12 hours minutes, between 30 minutes and 6 hours, between 60 and 180 minutes, between 80 and 150 minutes, between 100 and 140 minutes, between 110 and 130 minutes or between 115 and 125 minutes.

[0109] In a second aspect of the invention, there is provided a recycled first constituent part of a black mass material.

[0110] The recycled first constituent part may be as defined above. The black mass material may be as defined above.

[0111] The recycled first constituent part may be obtained using the method of the first aspect.

[0112] In a third aspect of the invention, there is provided a recycled second constituent part of a black mass material.

[0113] The recycled second constituent part may be as defined above. The black mass material may be as defined above.

[0114] The recycled second constituent part may be obtained using the method of the first aspect.

[0115] In a fourth aspect of the invention, there is provided a use of the recycled first constituent part of the second aspect and / or the recycled second constituent part of the third aspect in an electrode.

[0116] In a fifth aspect of the invention, there is provided an electrode comprising the recycled first constituent part of the second aspect and / or the recycled second constituent part of the third aspect.

[0117] In a sixth aspect of the invention, there is provided a use of the recycled first constituent part of the second aspect and / or the recycled second constituent part of the third aspect, or the electrode of the fifth aspect, in a battery. In a seventh aspect of the invention there is provided a battery comprising the recycled first constituent part of the second aspect and / or the recycled second constituent part of the third aspect, or the electrode of the fifth aspect.

[0118] All features described herein (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined with any of the above aspects in any combination, except combinations where at least some of such features and / or steps are mutually exclusive.

[0119] For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying Figures, in which:-

[0120] Figure 1 is an optical microscopy image of 1 %v / v vegetable oil droplets in DI water; Figure 2 shows the results of particle size analysis for 1 %v / v vegetable oil and 1 %v / v kerosene emulsions in DI water;

[0121] Figure 3 is an image showing the behaviour of graphite, a blend of lithium nickel manganese cobalt oxides (NMC622) and a graphite / NMC622 blend when added to an oil-in-water emulsion;

[0122] Figure 4 shows images of a) flocculated graphite particles in an oil-in-water emulsion solution after ultrasonication; and b) the flocculated graphite obtained by sieving; Figure 5 shows SEM images of a) graphite / NMC622 "black mass" blend before separation; b) graphite obtained from the separation process; and (c) NMC622 obtained from the separation process;

[0123] Figure 6 is a schematic diagram showing the interaction between graphite particles (irregular, potato shapes), NMC particles (circular shapes) and oil, with ultrasonic agitation; and

[0124] Figure 7 shows SEM images of a) a graphite and Lithium Manganese Oxide (LMO) / Lithium Nickel Manganese Cobalt Oxide (NMC) blend before heat treatment and separation; b) graphite obtained from the separation process after 300 °C heat treatment; c) LMO / NMC obtained from the separation process after 300 °C heat treatment; d) graphite obtained from the separation process after 500 °C heat treatment; e) LMO / NMC obtained from the separation process after 500 °C heat treatment.

[0125] Example 1 - Analysis of kerosene and vegetable oil-in-water emulsions

[0126] The inventors investigated the stability of kerosene and vegetable oil-in-water emulsions. A solution (60 mL) of 1 v / v% veg oil or kerosene in deionised (DI) water was made up. The solution was subject to 500 watt ultrasonication with the horn dipped in the solution for one minute.

[0127] Figure 1 shows an optical microscopy image of a vegetable oil-in-water emulsion after being subject to high power ultrasonication. The vegetable oil-in-water emulsion is milk like, containing smaller oil droplets with no flocculation or coalescence.

[0128] The oil droplet size distributions of the vegetable oil-in-water and kerosene oil-in- water emulsions were analysed by dynamic light scattering (DLS). Figure 2 shows the results of the particle size distribution analyses. The size distribution analyses show that the oil droplets in both emulsions have a narrow size distribution. There is a peak at around 200 nm for 1 %v / v vegetable oil, and a peak at around 400 nm for 1 %v / v kerosene. The small diameter of the droplets observed for both emulsions is due to the high power ultrasonication.

[0129] The inventors found that the vegetable oil-in-water emulsion is stable for at least four weeks, until the oil goes rotten. The inventors found that the kerosene oil-in-water emulsion is stable for at least a week, at which point the kerosene droplets tended to float to the top. This may be explained by the fact kerosene has a lower density than vegetable oil (0.80 g / cm3for kerosene vs. 0.92 g / cm3for vegetable oil).

[0130] Oil suspensions prepared with 0.5-1.5 v / v% veg oil showed a large number of oil droplets in water which could wet the graphite phase. These suspensions avoided flocculation, but at the same time were not too sparse. The stability of the spherical oil droplets obey Stokes' law, as shown in equation 1.

[0131] Where: V = particle (or droplet) rising or settling velocity, g = gravitational constant, = dynamic viscosity of water, pp= density of particle (or droplet), ps= density of water, d = diameter of particle (or droplet).

[0132] Equation 1 shows that the smaller the oil droplets, the more stable the emulsion will be. It also shows the more similar the density of the oil to the density of water, the more stable the emulsion solution will be. With ultrasonic action, large oil droplets may be split into two smaller droplets due to the shock wave generated by cavitation. The emulsion (oil droplet) diameter (Dv) is given by equation 2. wherein:

[0133] AP0= V2 (^)7(Eq. 3)

[0134] , and where y is the interfacial tension and AP o is the maximum sound pressure (Nnr2), p is the solution density (kgm-3), c is the sound velocity (ms-1), and A' is the cross- sectional area of the sonotrode (m2), Puit is ultrasonic power (watts). With other parameters unchanged, higher ultrasonic power and smaller sonotrode cross-section area will generate smaller oil droplet, as the power density would be larger.

[0135] Example 2- Separation of clean graphite and NMC622

[0136] A vegetable oil-in water emulsion was prepared as described in Example 1. 1 g of spherical graphite, NMC622 and a graphite / NMC622 blend were each separately added to 60 mL of oil-in-water emulsion. For the graphite / NMC622 blend, the NMC622 and spheric graphite were mixed in a ratio of 2: 1 by weight. Figure 3 shows images of the resulting emulsion-material mixes.

[0137] The inventors observed that when the NMC622 / graphite blend was added to the oil-in- water emulsion, the graphite particles mostly floated at the top of the emulsionmaterial mix as they are hydrophobic. Additionally, the NMC622 particles mostly settled at the bottom of the emulsion-material mix, as they are hydrophilic and have a higher density than water. However, there was some variation: some NMC622 particles were observed in the graphite floatation and some graphite particles were trapped in the NMC sediment.

[0138] The inventors subsequently subjected the NMC622 / graphite blend emulsion-material mix to vigorous agitation (500 watt ultrasonication for one minute). As shown in Figure 4a), it was found that ultrasonication caused the NMC622 / graphite blend to fully separate into two parts: flocculated lumps (mainly graphite), which floated in the emulsion, and sediment (mainly NMC622). The flocculated lumps and sediment were separated using a sieve (500 pm aperture size). In particular, the sediment (mainly NMC622) passes through the sieve apertures while the flocculated lumps (mainly graphite) were retained. The contents of the sieve was then washed with water to facilitate the removal of any sediment. Figure 4b) shows an image of the flocculated graphite obtained using this method.

[0139] The flocculated lumps and sediment were analysed by SEM, and the results are shown in Figure 5. As shown in Figure 5b), the flocculated lumps were made of graphite which is nearly 100% pure. The graphite particles appear dark and potato shaped. The NMC622 particles (secondary particle in Figure 5b) appear round and bright, as the metal element inside is heavier than carbon. As shown in Figure 5c), the sediment after sieving contained mainly NMC622 particles, and only a small amount of graphite particles.

[0140] The inventors repeated the process using a kerosene oil-in-water emulsion prepared as described in example 1. The results were comparable to those obtained using the vegetable-oil-in water emulsion.

[0141] When the black mass material is first added to the oil-in-water emulsion, the graphite and NMC622 particles are densely packed together in inclusive lumps, as shown at the bottom left of Figure 6. Under high power ultrasonication, these inclusive lumps are not stable and are broken into individual graphite particles (as shown at the top left of Figure 6), lumps of oil coated graphite particles (as shown at the top right of Figure 6), and the NMC622 particles set free from the inclusive lumps (as shown at the bottom right of Figure 6). The graphite used in lithium-ion battery (LiB) anodes generally has particles which are potato-shaped with dimensions in the range of 10 pm-20 pm.

[0142] In water, graphite particles stay suspended due to electrostatic forces on the particles which repel each other. A sub-micrometre oil droplet in the microemulsion can easily adsorb onto a graphite particle surface without becoming absorbed within the material. The oil enables the electrostatic surface charge of the graphite to be overcome and graphite particles with oil droplets adsorbed thereto can aggregate. Aggregation is driven by van der Waals attractive forces overcoming the surface energy of the graphite particles, and an ultimate lowering of the surface energy. Accordingly, the graphite particles with oil droplets adsorbed thereto tend to coagulate together when they collide, ultimately forming an aggregate lump of oil coated graphite (as shown at the top right of Figure 6). On the other hand, NMC622 particles are stable in the oil-in water emulsion as electrostatic forces dominate and the hydrophilicity of the metal oxide stops interaction with the oil phase. Since the MNC622 particles are hydrophilic, oil droplets do not absorb onto the NMC622 particles. Accordingly, the NMC622 particles remain as individual particles and do not coagulate.

[0143] Example 3 - Separation of anode and cathode powder

[0144] The inventors applied the methods described in examples 1 and 2 to a separation process for black mass obtained from LiBs. A blend of graphite and LMO (lithium manganese oxide) / NMC (lithium nickel manganese cobalt oxides) particles from Nissan Leaf battery anodes and cathodes was used as a black mass material.

[0145] Graphite in LiB anodes is usually coated with styrene-butadiene rubber (SBR) and sodium carboxymethyl cellulose (CMC) as a polymer binder. SBR / CMC is hydrophilic and so can be removed by washing with water. NMC (and LMO) particles in LiB cathodes are usually coated with polyvinylidene difluoride (PVDF) as polymer binder, which is hydrophobic. PVDF coated NMC (and LMO) particles behave like pristine graphite particles, i.e. tend to attract oil droplets in the emulsion solution and therefore cannot be separated from graphite. Accordingly, prior to the separation process, the binders were removed by heating the black mass material at 300 °C for 120 mins or at 500 °C for 30 mins.

[0146] The following protocol was then used to separate the graphite and NMC components of the black mass.

[0147] An emulsion (60 mL) of 1 v / v% veg oil in deionised (DI) water was prepared. The emulsion was subject to 500 watt ultrasonication with the horn dipped in the emulsion for one minute. 2 g black mass was added to 60 ml of the oil-in-water emulsion. The resulting mixture was ultrasonicated for one minute with horn dipped in the solution (500 watt). The obtained mixture contained dispersed particles and lumps of congregated particles. A sieve (500 pm aperture size) was used to separate the lumps of congregated particles from the dispersed particles. The congregated graphite particles were captured in the sieve. The dispersed NMC and LMO particles passed through the sieve. The sieved mixture comprising the dispersed NMC and LMO particles may subsequently be filtered or passed through a finer sieve (<lpm mesh) to isolate the NMC and LMO particles.

[0148] The aggregate lumps and dispersed particles were both analysed by SEM. Figure 7 shows SEM images of the powder samples before and after separation. In these images, the graphite particles appear dark and potato shaped; the NMC particles appear bright and round; and the LMO particles appear bright, with irregular shapes sizes.

[0149] After 500 °C treatment, the black mass is fully disintegrated into individual particles, while after treatment at 300 °C agglomerate chunks still exist in the black mass. Figures 7b) and c) show that the separated graphite and NMC (and LMO) for 300 °C treated black mass are both about 90 vol% pure. Figures 7d) and e) show that the separated graphite and NMC (and LMO) for 500 °C treated black mass are more than 98 vol% pure. Accordingly, ideally the polymer binders should be fully removed before using the separation protocol to separate the graphite from NMC (and LMO) particles.

[0150] Methods

[0151] Oil Droplet Size Distribution

[0152] The oil droplet size distribution was analysed by a dynamic light scattering machine (Zetasizer Nano-S, Malvern Instruments).

[0153] Ultrasonication

[0154] Ultrasonication was carried out using a device with the following specifications: Branson Sonics, 1.25DCXa20-V, 20 kHz, max power 1250 watt, diameter 20 mm cylinder sonotrode.

[0155] SEM

[0156] SEM (single electron microscopy) measurements were taken using an FEI Quanta 650 FEGSEM.

[0157] Materials

[0158] Commercial battery scale NMC622 and spheric graphite were (obtained from Dana TM4) used. The graphite particles had a diameter in the range 5-20 pm.

[0159] A black mass material of cathode and anode was prepared by blending delaminated leaf cell cathode (LMO / NMC) and anode powder (2: 1 by weight, Nissan company).

Claims

Claims1. A method for separating a black mass material into first and second constituent parts, wherein the first constituent part comprises or consists of particles of a hydrophobic material and the second constituent part comprises or consists of particles of a hydrophilic material, the method comprising: providing an emulsion, the emulsion comprising a first liquid phase dispersed as droplets in a second liquid phase, wherein the second liquid phase is or comprises water; contacting the emulsion with the black mass material to provide an emulsionmaterial mix and thereby allowing the particles of the hydrophobic material to be adsorbed into or onto the droplets of the first liquid phase, and the particles of the hydrophilic material to remain in the second liquid phase; and- separating the particles of the hydrophobic material and the particles of the hydrophilic material to thereby separate the first and second constituent parts of the black mass material.

2. The method according to claim 1, wherein the hydrophobic material comprises or consists of carbon.

3. The method according to any preceding claim, wherein the hydrophilic material is or comprises a metal oxide.

4. The method according to claim 3, wherein the hydrophilic material comprises or is a lithium nickel manganese cobalt oxide (NMC) compound, a lithium cobalt oxide (LCO), a lithium manganese oxide (LMO) compound, a lithium nickel cobalt aluminium oxide (NCA) or a lithium iron phosphate (LFP) compound.

5. The method according to any preceding claim, wherein separating the particles of the hydrophobic material and the particles of the hydrophilic material comprises sieving the emulsion-material mix.

6. The method according to any preceding claim, wherein the emulsion and the black mass material are contacted in a ratio of between 1 and 1000 mL of emulsion per 1 g black mass, between 10 and 100 mL of emulsion per 1 g black mass, between 15 and 50 mL of emulsion per 1 g black mass, between 20 and 40 mL of emulsion per 1 g black mass, between 25 and 35 mL of emulsion per 1 g black mass or between 28 and 32 mL of emulsion per 1 g black mass.

7. The method according to any preceding claim wherein the emulsion comprises the first liquid phase in an amount of between 0.01 v / v% and 10 v / v%, between 0.1 v / v% and 5.0 v / v%, between 0.2 and 2.5 v / v%, between 0.3 and 2.0 v / v%, between 0.4 and 1.75 v / v%, between 0.5 and 1.5 v / v%, between 0.6 and 1.4 v / v%, between, 0.7 and 1.3 v / v%, between 0.8 and 1.2 v / v%, between 0.9 and 1.1 v / v% or between 0.95 and 1.05 v / v%.

8. The method according to any preceding claim wherein the emulsion comprises the second liquid phase in an amount of between 90 v / v% and 99.9 v / v%, between 95.0 v / v% and 99.9 v / v%, between 96.0 and 99.8 v / v%, between 97.0 and 99.7 v / v%, between 98.0 and 99.6 v / v%, between 98.25 and 99.5 v / v%, between 98.5 and 99.4 v / v%, between, 98.7 and 99.3 v / v%, between 98.8 and 99.2 v / v%, between 98.9 and 99.1 v / v% or between 98.95 and 99.05 v / v%.

9. The method according to any preceding claim, wherein the emulsion is emulsifier-free.

10. The method according to any preceding claim, wherein the first liquid phase comprises or consists of one or more non-polar, substantially water-immiscible components.

11. The method according to claim 10, wherein the first liquid phase comprises or consists of kerosene and / or vegetable oil.

12. The method according to any preceding claim, wherein the droplets of the first liquid phase in the emulsion have an average diameter of less than 700 nm, less than 600 nm, less than 500 nm or less than 450 nm.

13. The method according to any preceding claim, wherein the second liquid phase consists substantially of water.

14. The method according to any preceding claim, wherein the first liquid phase has a density which is different to the density of the second liquid phase by less than 30%, less than 25% or less than 20%.

15. The method according to any preceding claim, wherein the black mass material comprises or consists of an agglomerate or plurality of agglomerates, and the method comprises breaking up the agglomerate or agglomerates of black mass material.

16. The method of claim 15, wherein breaking up the agglomerate or the plurality of agglomerates of the black mass material is conducted simultaneously or subsequently to contacting the emulsion with the black mass material.

17. The method of claim 15 or claim 16, wherein breaking up the agglomerate or the plurality of agglomerates of the black mass material is conducted by applying a mechanical force to black mass material, wherein the mechanical force is an ultrasonic wave.

18. The method according to any preceding claim, wherein the black mass material is binder free.

19. The method according to any one of claims 1 to 17, wherein the black mass material comprises a polymer binder and the method comprises removing the polymer binder from the black mass material to provide a binderless black mass material.

20. A recycled first constituent part of a black mass material comprising or consisting of particles of a hydrophobic material, wherein the recycled first constituent part is obtained using the method of any one of claims 1 to 19.

21. A recycled second constituent part of a black mass material comprising or consisting of particles of a hydrophilic material, wherein the recycled first constituent part is obtained using the method of any one of claims 1 to 19.

22. Use of the recycled first constituent part of a black mass material according to claim 20, and / or the recycled second constituent part of a black mass material according to claim 21, in an electrode.

23. An electrode comprising the recycled first constituent part of a black mass material according to claim 20, and / or the recycled second constituent part of a black mass material according to claim 21.

24. Use of the recycled first constituent part of a black mass material according to claim 20, the recycled second constituent part of a black mass material according to claim 21 and / or the electrode according to claim 23, in a battery.

25. A battery comprising the recycled first constituent part of a black mass material according to claim 20, the recycled second constituent part of a black mass material according to claim 21 and / or the electrode according to claim 23.

Images