Methods for refining and / or recycling black mass, black mass, and its utilization
By adding promoter elements and metal salts to metal-free black mass, the method enhances its performance for electrolytic water splitting, addressing the disposal and resource conservation issues of recycled battery materials.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- ENINO GAMBEHER
- Filing Date
- 2024-03-11
- Publication Date
- 2026-04-10
AI Technical Summary
The metal-free black mass generated during the recycling of used batteries for electric vehicles is often discarded due to its poor performance and is thermally utilized, leading to CO2 emissions, while valuable resources like lithium, manganese, cobalt, and nickel are wasted.
A method involving the addition of promoter elements such as N, P, S, and/or B to metal-free black mass, along with specific metal salts, to enhance its performance for applications beyond thermal utilization, particularly as electrodes in electrolytic water splitting.
The treated black mass exhibits improved performance and stability, making it suitable for use as electrodes in electrolytic water splitting, reducing waste and conserving valuable resources.
Smart Images
Figure 2026510793000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for purifying and / or recycling black mass, black mass, and its use. Black mass is generated particularly in the recycling process of used batteries for electric vehicles, and its generation amount is increasing, so it is attracting attention as a starting material for further recycled products. Resources such as lithium, manganese, cobalt, nickel, etc. required for the production of used batteries for electric vehicles are scarce. Therefore, at the end of the battery life, it is desirable that these raw materials remain within the recycling cycle as completely as possible.
[0002] Therefore, used batteries are decomposed into their respective constituent materials as much as possible. In this process, black mass containing metals is generated, and the black mass can include a granular mixture of raw materials that may contain metals and / or metal oxides such as lithium, graphite (carbon), and cobalt (oxide), copper (oxide), nickel (oxide), manganese (oxide), and / or iron (oxide), etc., depending on the battery type. These constituent materials can be separated by conventional methods such as sieving, magnetic methods, or hydrometallurgical methods, whereby black mass can be obtained in a metal-free form. While metals and metal oxides are used, for example, in the production of new batteries, the metal-free black mass mainly composed of damaged graphite having defects and pores is currently stored as unused waste or subjected to a combustion process, where CO2 harmful to the climate is generated.
Summary of the Invention
Problems to be Solved by the Invention
[0003] An object of the present invention is to provide a method for purifying and / or recycling black mass, particularly to process the metal-free black mass so that the resulting black mass is suitable for uses other than thermal utilization. Generating CO2 by burning black mass should be avoided.
Means for Solving the Problems
[0004] According to the present invention, this objective is achieved by a method having the features of claim 1, a black mass having the features of claim 9, and a use having the features of claim 10. Further advantageous embodiments and developments are specified in dependent claims 2 to 8.
[0005] The present invention relates to a method for purifying and / or recycling black mass, and includes the following steps: a) A process for providing black mass that does not contain metals, b) A step of treating black mass that does not contain a predetermined metal and / or metal oxide content with a metal salt, and / or c) A step of adding a promoter element selected from the group consisting of N, P, S, and / or B to black mass that does not contain the aforementioned metal or black mass having the aforementioned predetermined metal and / or metal oxide content.
[0006] According to the present invention, the metal-free black mass is given a predetermined metal and / or metal oxide content and / or a promoter element selected from the group consisting of N, P, S, and / or B. By adding the predetermined metal and / or metal oxide content, the performance of the black mass can be brought to a desired level, for example, in applications as electrodes. The percentage composition of the metal and / or metal oxide can be advantageously optimized, and thus the black mass having the predetermined metal and / or metal oxide content exhibits more optimized and reproducible performance. Although we do not wish to be bound by theory, it has been pointed out that the promoter element selected from the group consisting of N, P, S, and / or B functions as an external atom, particularly a promoter element atom, in the graphite of the black mass, stabilizing or "repairing" vacancies in the graphite structure. In graphite, carbon atoms are arranged in a hexagonal network, i.e., hexagons, thereby forming a hexagonal layered lattice. In each layer, each carbon atom is bonded to three other atoms, forming a two-dimensional hexagonal network structure. Intra-layer bonding is strong, but inter-layer bonding is very weak, so layers can relatively easily slide and even delaminate. This affects the physical properties of graphite. The addition of promoter elements stabilizes the graphite structure by having the elements occupy vacancies in the damaged structure. Promoter elements can be added in amounts ranging from doping levels to substoichiometric amounts.
[0007] In this invention, "metal-free black mass" means black mass with a metal concentration of less than 0.01% by mass. Metal-free black mass can be obtained, for example, from metal-containing black mass by a wet chemical method and can be purchased, for example, from Duesenfeld GmbH (Wendeburg, Germany).
[0008] Preferably, sonication is performed in step b) or step c). Sonication can improve yield, increase reaction rate, and / or achieve milder reaction conditions. Therefore, sonication is an efficient and harmless means of activating, promoting, and accelerating the process carried out in the step.
[0009] In a preferred embodiment, the metal salt used in step b) is selected from metal acetates and / or metal halides having metals belonging to block d and / or block f. More preferably, the d-block metal is an early and / or late transition metal, i.e., a transition metal of group IV, V, IX and / or X. Even more preferably, the metal salt used in step b) is M(OAc)2, where M is Ni, Co, Fe or Mn, or a mixture thereof.
[0010] Preferably, the metal salt used in step b) is a mixture of the following: Ni(OAc)2 and Fe(OAc)2, Ni(OAc)2 and Co(OAc)2, Co(OAc)2 and Fe(OAc)2, · Mn(OAc)2 and Co(OAc)2, or ·Ni(OAc)2, Fe(OAc)2 and Co(OAc)2. Preferably, the ratio of each metal salt of Ni(OAc)2 to Fe(OAc)2, Ni(OAc)2 to Co(OAc)2, Co(OAc)2 to Fe(OAc)2, or Mn(OAc)2 to Co(OAc)2 is in the molar ratio range of 9:1 to 1:9, more preferably 5:1 to 1:5, and even more preferably 2:1 to 1:2. The ratio of Ni(OAc)2:Fe(OAc)2:Co(OAc)2 is, for example, 1:1:1.
[0011] Preferably, the metal salt used in step b) is Fe(OAc)2, or a mixture of Ni(OAc)2 and Fe(OAc)2.
[0012] In a preferred embodiment, step c) is carried out by treating the black mass with red phosphorus, S8, thiourea, urea, hydrazine, hydrazine sulfate, boric acid, diboron trioxide, or ammonia. Preferably, step c) is carried out once with one of the starting materials. Alternatively, step c) may be repeated to add a plurality of promoter elements selected from N, P, S, and / or B to the black mass.
[0013] The promoter element is selected from nitrogen, phosphorus, sulfur, and / or boron. Preferably, the promoter element is nitrogen and / or sulfur, and more preferably nitrogen.
[0014] In a preferred embodiment, ammonia is used in step c). The performance of the black mass can be improved by the addition of nitrogen. To introduce nitrogen into the graphite, the black mass is heated in a stream of ammonia gas as a nitrogen source for 1 hour or more, preferably 1 to 10 hours, at 200°C to 400°C, more preferably 300 to 350°C. In this way, it is demonstrated that nitrogen is incorporated into the black mass. The nitrogen in the material can be confirmed based on the XPS (X-ray photoelectron spectroscopy) spectrum. Alternatively, nitrogen may be added using N2, urea, or hydrazine.
[0015] Alternatively or additionally preferred, the promoter element is sulfur. The addition of sulfur significantly increases the activity of black mass, for example, in applications as an electrode for hydrogen production in electrolytic water splitting. The addition of sulfur may, if these metals are present in the black mass, lead to the formation of small amounts of metal sulfides such as NiS, CoS, and MnS, which can promote electrolytic hydrogen production. Sulfur can be added using, for example, S8 or hydrogen sulfide.
[0016] Sulfur and nitrogen can be added simultaneously by reacting with thiourea, which functions as both a nitrogen and sulfur source.
[0017] Alternatively or additionally, the promoter element is preferably phosphorus. Phosphorus can be added using, for example, red phosphorus.
[0018] Alternatively or additionally, the promoter element is preferably boron. Boron can be added, for example, using boric acid, or more preferably using diboron trioxide.
[0019] Steps b) and c) are preferably carried out in succession. In a preferred embodiment, step b) is carried out prior to step c). That is, a predetermined amount of metal and / or metal oxide is first added to a metal-free black mass, and then a promoter element is added to a black mass having a predetermined metal and / or metal oxide content.
[0020] In an alternatively preferred embodiment, step c) is carried out prior to step b). That is, first a promoter element is added to a metal-free black mass, and then a predetermined amount of metal and / or metal oxide is added to the metal-free black mass containing the promoter element to obtain a promoter element-containing black mass having a predetermined metal and / or metal oxide content.
[0021] In a preferred embodiment, step a) is followed by step c) using ammonia as the promoter element, and then step b) is performed with Fe(OAc)2, or a mixture of Ni(OAc)2, Fe(OAc)2, and Co(OAc)2. The black mass thus obtained exhibits high performance when used as an electrode in electrolytic water splitting.
[0022] The metal-free black mass provided in step a) is preferably a purchased product. The black mass is a material obtained from used batteries used for driving an electric vehicle (more preferably an electric passenger car). In particular, the metal-free black mass is obtained by mechanical recycling of a used electric vehicle battery to be recycled. After disassembling the exterior and device electronic components of the used battery, the mechanical recycling includes a plurality of grinding, sorting, and classification steps for the remaining parts, and as a result, a metal-free black mass is obtained and processed. The black mass may initially contain a layer material, an electrode material, and / or an electrolyte material, and is preferably a granular mixture. Active materials of the electrode, such as graphite and lithium transition metal composite oxides (e.g., cobalt, nickel, manganese), tend to be enriched in the black mass. However, the composition of the black mass depends on the chemical composition of the used battery to be recycled. The black mass containing metal and / or metal oxide is converted into a metal-free black mass, for example, by a wet chemical method as described above, and the metal and metal oxide can be used for other purposes. The metal-free black mass can be purchased, for example, from Duesenfeld GmbH (Vendenburg, Germany). The metal-free black mass provided in step a) may alternatively be obtained by exposing a similarly purchasable black mass containing metal (Duesenfeld GmbH, Vendenburg, Germany) to an inorganic acid. The inorganic acid is preferably H2SO4.
[0023] The present invention also relates to a black mass obtained by the method according to one or more of the above-described embodiments. The black mass contains a content of one or more promoter elements and / or a predetermined metal and / or metal oxide.
[0024] The present invention further relates to the use of the black mass obtained by the method, and examples of the use include use as an electrode material, an electrochemical catalyst, and a heterogeneous catalyst.
[0025] In a preferred embodiment, the black mass obtained by the method according to the present invention is used as an electrode material. Preferably, the black mass is used as an anode or cathode electrode material in the electrolysis of water to generate hydrogen and oxygen. The electrode material is preferably part of a working electrode used to generate oxygen or hydrogen.
[0026] In a preferred embodiment, the black mass obtained by the method according to the present invention is used as an electrochemical catalyst.
[0027] In a preferred embodiment, the black mass obtained by the method according to the present invention is used as a heterogeneous catalyst.
[0028] The present invention will be described in more detail below with reference to the accompanying drawings and examples. The figures are schematic and not to scale.
Brief Description of the Drawings
[0029] [Figure 1] X-ray powder diffraction pattern of the black mass after treatment with H2SO4 or NH3. [Figure 2] Cyclic voltammogram of the black mass according to the first embodiment used as a working electrode for oxygen generation. [Figure 3] Chronopotentiometry of the black mass according to the first embodiment used as a working electrode for oxygen generation. [Figure 4] Cyclic voltammogram of the black mass according to the second embodiment used as a working electrode for oxygen generation. [Figure 5] Chronopotentiometry of the black mass according to the second embodiment used as a working electrode for oxygen generation. [Figure 6] Cyclic voltammogram of the black mass according to the first embodiment used as a working electrode for hydrogen generation. [Figure 7] Chronopotentiometry of the black mass according to the first embodiment used as a working electrode for hydrogen generation. [Figure 8]A cyclic voltammogram of black mass according to a second embodiment used as a working electrode for hydrogen generation. [Figure 9] Chronopotentiometry of black mass according to a second embodiment used as a working electrode for hydrogen generation. [Modes for carrying out the invention]
[0030] Figure 1 shows the X-ray powder diffraction pattern of black mass. Figure 1 shows the first X-ray powder diffraction pattern (1) of metal-free black mass obtained by treating metal-containing black mass with H2SO4 according to Example 1. Furthermore, Figure 1 shows the second X-ray powder diffraction pattern (2) of black mass obtained by treating metal-free black mass with NH3 according to Example 2, which will be described later.
[0031] Figure 2 shows a cyclic voltammogram of electrolytic water splitting to generate oxygen using black mass as the working electrode according to the first embodiment. The sweep rate was 5 mV / s and measured on nickel foam. Measurements in the second and sixth cycles were performed using a three-electrode configuration. An Hg / HgO electrode was used as the reference electrode, and its potential was normalized to a reversible hydrogen electrode (RHE).
[0032] The electrode material used as the working electrode was black mass obtained in Example 3 described below. To prepare the working electrode, an electrolytic cell was prepared comprising an electrode based on nickel foam and an auxiliary electrode made of nickel foam in 10 mL of acetone as a solvent. 25 mg of black mass and 2 mg of iodine were introduced into the solution. Then, a voltage of 10 V was applied to the electrode for 30 seconds to 10 minutes in air at room temperature. 2 mg of iodine and 25 mg of black mass were sufficient to prepare 10 to 15 working electrodes. The working electrodes thus obtained were washed with an organic solvent and dried in air.
[0033] Figure 3 shows the 100 mA / cm² of the working electrode. 2 This shows the chronopotentiometry at the current density. The measurement was performed on a 1 × 1 cm nickel foam.
[0034] Figure 4 shows a cyclic voltammogram of electrolytic water splitting to generate oxygen using black mass as the working electrode according to the second embodiment. The sweep rate was 5 mV / s and measured on Ni foam. Measurements in the second and sixth cycles were performed using a three-electrode configuration. An Hg / HgO electrode was used as the reference electrode, and its potential was normalized to RHE.
[0035] The electrode material used as the working electrode was black mass obtained in Example 4 described below. To prepare the working electrode, an electrolytic cell was prepared, comprising a nickel foam electrode and a nickel foam auxiliary electrode in 10 mL of acetone as a solvent. 25 mg of black mass and 2 mg of iodine were introduced into the solution. A voltage of 10 V was then applied to the electrode for 30 seconds to 10 minutes in room temperature air. 2 mg of iodine and 25 mg of black mass were sufficient to prepare 10 to 15 working electrodes. The working electrodes were washed with an organic solvent and dried in air.
[0036] Figure 5 shows the working electrode at 100 mA / cm² for oxygen generation under the same conditions as described in Figure 4. 2 This shows the chronopotentiometry at the current density. The measurement was performed on a 1 × 1 cm nickel foam.
[0037] Figure 6 shows a cyclic voltammogram of a working electrode for hydrogen generation using black mass obtained by the method according to the first embodiment of the present invention. The working electrode was obtained as described in Figure 2.
[0038] Figure 7 shows the -100 mA / cm² of the working electrode for hydrogen generation under the same conditions as described in Figure 6. 2 This shows the chronopotentiometry at the current density. The measurement was performed on a 1 × 1 cm nickel foam.
[0039] Figure 8 shows a cyclic voltammogram of the working electrode for hydrogen generation using black mass according to the second embodiment. The working electrode was obtained as described in Figure 4.
[0040] Figure 9 shows the -100 mA / cm² of the working electrode for hydrogen generation under the same conditions as described in Figure 8. 2 This shows the chronopotentiometry at the current density. The measurement was performed on a 1 × 1 cm nickel foam. [Examples]
[0041] [Example 1] Production of metal-free black mass: As a starting material, metal-containing black mass based on recycled material from used batteries used to power electric vehicles was used. The recycled material is a recycled material based on LFP batteries (lithium iron phosphate batteries) and was supplied by Duesenfeld GmbH (Wendeburg, Germany). The metal oxides in the black mass that do not contain precious metals include iron oxides supported on graphite. The metal-containing components (i.e., iron oxides) were washed away from this metal-containing black mass using sulfuric acid to obtain metal-free black mass. Therefore, the recycled material was crushed, suspended in an aqueous solution of 2.5 M H2SO4, treated at 60°C for 5 hours, washed with water and acetone, and dried in air. The X-ray powder diffraction pattern of the thus obtained metal-free black mass is shown in diffraction pattern (1) of Figure 1.
[0042] [Example 2] Addition of nitrogen as a promoter element: The metal-free black mass obtained in Example 1 was heated in a furnace at 300°C for 6 hours in NH3. Before starting heating, the furnace was purged with NH3 for 2 hours, and then the temperature was increased at 300 K / h. After that, it was allowed to cool naturally to room temperature. The X-ray powder diffraction pattern of the metal-free black mass obtained in this way is shown in the diffraction pattern (2) of Figure 1.
[0043] [Example 3] Addition of metal (oxide) and promoter element: 100 mg of metal-free black mass obtained in Example 1 was suspended in a solution of 10 mL of ethanol and 0.02 g of Fe(OAc)2 and sonicated for 2 hours. The solvent was evaporated by N2 flow for 2 hours. The product was pulverized and placed in a tubular furnace, and the system was purged with NH3 for 1 hour. The sample was then heated to 300°C at 300 K / h, held for 2 hours, and then allowed to cool naturally.
[0044] [Example 4] 100 mg of black mass obtained in Example 2 was suspended in a solution of 10 mL of ethanol and 0.02 g of Fe(OAc)2 and sonicated for 2 hours. The solvent was evaporated by a stream of N2 for 2 hours. The product was pulverized and placed in a tubular furnace, and the system was purged with N2 for 1 hour. The sample was then heated to 300°C at 300 K / h, held for 2 hours, and then allowed to cool naturally. [Explanation of symbols]
[0045] 1: First X-ray powder diffraction pattern 2: Second X-ray powder diffraction pattern 3: Second Cycle 4: 6th Cycle
Claims
1. A method for refining and / or recycling black mass, comprising the following steps: a) A process for providing black mass that does not contain metal, b) A step of treating metal-free black mass with a metal salt to obtain black mass having a predetermined metal and / or metal oxide content, and / or c) A step of adding a promoter element selected from the group consisting of N, P, S, and / or B to a metal-free black mass or a black mass having the predetermined metal and / or metal oxide content.
2. The method according to claim 1, characterized in that sonication is performed in step b) or step c).
3. The metal salt used in step b) is selected from metal acetates and / or metal halides having metals belonging to block d and / or block f, and preferably the metal salt used in step b) is M(OAc) 2 The method according to claim 1 or 2, wherein M is Ni, Co, Fe, or Mn, or a mixture thereof.
4. The metal salt used in step b) is Ni(OAc) 2 and Fe(OAc) 2 ; Ni(OAc) 2 and Co(OAc) 2 ; Co(OAc) 2 and Fe(OAc) 2 ; Mn(OAc) 2 and Co(OAc) 2 ; or a mixture of Ni(OAc) 2 and Fe(OAc) 2 and Co(OAc) 2 , preferably, the ratio of each metal salt in the mixture of Ni(OAc) 2 and Fe(OAc) 2 , Ni(OAc) 2 and Co(OAc) 2 , or Mn(OAc) 2 and Co(OAc) 2 is in the range of molar ratio 9:1 to 1:
9. The method according to claim 3, characterized in that.
5. Step c) is red phosphorus, S 8 The method according to any one of claims 1 to 4, characterized in that it is carried out by treating black mass with thiourea, urea, hydrazine, hydrazine sulfate, boric acid, diboron trioxide, or ammonia, and step c) is optionally repeated.
6. The method according to the present invention, characterized in that ammonia is used in step c).
7. The method according to any one of claims 1 to 6, characterized in that step b) is performed prior to step c), or step c) is performed prior to step b).
8. The black mass provided in step a) is obtained by exposing metal-containing black mass to an inorganic acid, wherein the inorganic acid is preferably H 2 SO 4 The method according to any one of claims 1 to 7, characterized in that it is the same as the method according to any one of claims 1 to 7.
9. Black mass obtained by the method according to any one of claims 1 to 8.
10. Use of the black mass described in claim 9 as an electrode material, an electrochemical catalyst, or a heterogeneous catalyst.