Loss-free process for manufacturing cathode active materials without generating wastewater

Abstract

This invention relates to a resource-saving process for producing alkali metal-containing cathode active materials, which does not require the use of additional purified water due to the use of concentrated water from the precursor. The invention also relates to the treatment (purification) of alkali metal-containing wash water generated during the production of cathode active materials. According to this invention, the alkali metal precursor recovered in the process is returned to the production process.

Description

Technical Field

[0001] The present invention relates to a resource-saving process for manufacturing an alkali metal-containing cathode active material, which does not require the use of additional process water due to the use of concentrated water from a precursor. The present invention also relates to the treatment of alkali metal-containing wash water generated during the manufacture of the cathode active material. According to the present invention, the recovered alkali metal precursor is returned to the manufacturing process.

Background Art

[0002] Electromobility has been severely criticized due to the lack of sustainability in the manufacture of electric batteries, particularly cathode active materials containing lithium ions. Both the extraction of lithium and the lack of a closed cycle, and particularly the limited availability of lithium, have become major challenges for the manufacturing process. According to the current state of the art, the manufacture of cathode active materials is not considered a "green technology". Not only the high energy requirements, but also the high demand for lithium and oxides of other metals such as nickel, cobalt, iron, and manganese, cast doubt on the future of electromobility. Therefore, the present invention is particularly important for the future technology of electromobility. Especially in lithium-ion batteries or other alkali metal-ion batteries, only by closing the cycle and preventing wastewater and waste from the manufacturing process can electromobility have a future. The present invention enables the manufacture of cathode active materials without wastewater and waste. Ri

[0003] ​The emission levels and required limits from manufacturing facilities for alkali metals (especially lithium), nickel, cobalt, manganese, sulfates, nitrates, and phosphates are often impractical with current technological capabilities. Therefore, evaporation plants are frequently used to concentrate wastewater. The high energy consumption required for this is inconsistent with the concept of sustainability. Further processing and recovery of alkali metals from concentrates (bottom products) is also significantly more complex and costly than the alkali metal-containing solutions produced in this invention through optimized material flows. [Overview of the project] [Problems that the invention aims to solve]

[0004] Therefore, an object of the present invention is to provide a wastewater and waste-free process for producing cathode active materials, in which, by closing the cycle, the raw materials are exclusively converted into products, impurities (e.g., sulfates, nitrates, carbonates, etc.) are separated and converted into usable products. The loss of raw materials, particularly alkali metals (e.g., lithium) and other metals contained in the precursor products should be removed or at least minimized, and the generation of waste should be prevented. A further object of the present invention is that the entire production process does not require additional water, particularly desalinated or deionized water. [Means for solving the problem]

[0005] Subject matter of the invention This problem relates to claim 1 , 14, and 15 The problem is solved by a method that includes the features described herein. A favorable embodiment is the subject of a dependent claim.

[0006] The present invention provides a method comprising the following steps. a) Providing one or more metal compounds, b) A step of providing an alkali metal compound, c) Dehydrating / drying the alkali metal compound, and dehydrating / drying the metal compound and / or the recovered alkali metal-rich material stream (60), and using one or more concentrates or concentrated mixtures resulting therefrom as washing water; d) A step of manufacturing a metal oxide lattice, incorporating alkali metals, and thereby obtaining a CAM precursor (26), e) Washing the CAM precursor (26) obtained from step d) with the washing water obtained from step c), and separating the washed CAM product (30) into solid / liquid components.

[0007] The present invention further includes the following steps. f) The step of washing the filter device (32) with the washing water (38) and returning the rinse water (40) to the washing water reservoir (47), g) Maintaining a constant concentration of alkali metal and acid residue anions by removing the alkali metal-rich solution from the wash water storage container (47) and compensating for the volume by adding the alkali metal-poor solution (54) and / or the concentrate or the concentrated mixture, h) The step of processing the alkali metal-rich solution from step g) to obtain the alkali metal-rich material stream (60), i) A step of dehydrating the alkali metal-rich material stream (60) and returning the recovered alkali metal precursor (62) to the manufacturing process.

[0008] especially, The present invention provides a method comprising the following steps. a) Step 3: Provide one or more metal compounds 7, b) Step 1: Provide alkali metal compound 5, c) Dehydrating / drying the alkali metal compound 5 in device 9 and / or dehydrating / drying the metal compound 7 in device 11 and / or dehydrating / drying the recovered alkali metal-rich product 60, preferably in device 63 or alternatively in device 9, separating the resulting concentrates 15, 19 and 64, collecting them in a flocculation tank 55, moving the flocculation mixture 43 to a wash water reservoir 47, and using it as wash water 34 for the washing process and wash water 38 for washing the filter unit 32. d) A step of manufacturing a metal oxide lattice and incorporating alkali metal units 24, e) obtained from step d) Ta C The AM precursor (alkali metal-metal oxide lattice) is washed in the device 28 with washing water 34 from step c) and from the storage container 47, and the washed CAM product 30 is separated into solid / liquid by unit 32, separating it into filtrate 42 and solid 44. f) The filter device 32 is washed with the wash water 38 from the storage unit 47, and the rinse water 40 is returned to the wash water storage unit 47. Step , g) The alkali metal and acid residue anion concentrations are maintained by removing the alkali metal-rich material stream 48 from the wash water storage unit 47 and compensating for its volume by supplying alkali metal-poor material stream 54 and / or concentrate 46 and / or concentrate 43. P, h ) Process alkali metal-containing material flows 48, 50, 52, 56 from step f) to obtain alkali metal-rich material flows, and dewater material flow 60 in unit 63. Steps to take , and i) The step of returning the recovered alkali metal precursor 62 to the manufacturing process, preferably using a mixing device 21.

[0009] In the method according to the present invention, the wash water 48 from tank 47 from step f) is preferably passed through a solid separator 65, which may also be optional. The solid separator 65 preferably consists of a solid filter 49 (membrane filtration) having a filtrate collection tank 51 and / or a sedimentation tank 69 (e.g., a tilt filter) and / or a chamber filter press 73 (or decanter). The resulting "solid-free or low-solid solution" 50 and / or 68 and / or 72 is preferably collected in the collection tank 51. Figure 4 shows a solid separator unit 65 with material flow.

[0010] According to an advantageous embodiment of the present invention, solid Free The solution 52 is supplied to a "concentration unit" 53 and / or a membrane separation process 61 (e.g., diffusion dialysis), thereby the resulting "alkali metal-poor solution" 54 from the concentration unit 53 is returned to the wash water reservoir 47, and the alkali metal-rich solution 56 is separated.

[0011] According to the present invention, the alkali metal-rich solution 56 is subjected to a membrane separation process 61, whereby a flow 60 of an alkali metal-rich / sulfate poor material is obtained, whereby the flow 60 of the alkali metal-rich material is preferably dehydrated and the dehydrated alkali metal product 62 of the storage is dehydrated with the alkali metal-containing precursor 1 or the precursor 1 at 9, and the concentrate 64 is supplied to the concentrate collection tank 55, from which the concentrated mixture 43 is further supplied to the wash water storage 47. Depending on the product line or additive used, the alkali metal-rich / low sulfate material flow 60 may have fewer other acid residue anions such as nitrates, carbonates, phosphates, etc. instead of fewer sulfates.

[0012] According to an advantageous embodiment of the invention, the filtration in step e) is carried out by means of a chamber filter press 32. The resulting low-solids filtrate 42b and the return flow 40 resulting from the washing of the chamber filter press filter cloth are supplied to the wash water storage 47.

[0013] The alkali metal concentration in the wash water storage 47 is kept constant throughout the process by discharging the material flow 48.

[0014] Furthermore, in the sense of the present invention, it is preferable that the respective material flows 43, 46, 54, 40, and 42b from the drying, dehydration, separation, and filtration processes be supplied in cascade to the wash water reservoir 47. The cascade is shown in Figure 3. As expected, the materials flow with the lowest alkali metal concentrations; namely, concentrates 15, 19, and 64, or concentrate mixtures 43 and concentrate 46. These are introduced to the rear end of cascade 47.3, followed by material flow 54 into cascade 47.2, material flows 40 and 42b into cascade 47.1, from which they are introduced to the wash process reservoir 47.0. Wash water for material flows 34, 38, and 48 is then taken in directly or exclusively from 47.0, which has the highest alkali metal concentration. The cascade may consist of individual tanks connected to each other via a pump (47.3 → 47.2 → 47.1 → 47.0). However, any other type of cascade can also be used. This cascading ensures that the concentration remains very constant when withdrawing from the reservoir 47.0, and that concentration fluctuations due to different inflows are avoided.

[0015] This process does not require water, distilled water, or deionized water supplied from an external source. Therefore, according to a further advantageous embodiment of the present invention, no external deionized water is supplied.

[0016] The precursor 7 used in the method according to the present invention preferably consists of metal hydroxides containing metal Ni, Mn, Co, Al, Fe, Ti, Ta, Zr, Nb, or other transition metals or lanthanides, or mixtures thereof, with the combination of Co, Ni, Fe, Mn and lithium (precursor 5) being the most preferred.

[0017] Alkali metal compound 5 is preferably an alkali metal hydroxide or alkali metal carbonate. Lithium as lithium hydroxide monohydrate (LiOH·H2O) with a hydrate content of about 43% is most preferred. + That percentage is only about 16.5%.

[0018] The additive 22 for the production of alkali metal-metal oxide compounds (particularly lithium metal oxides) is preferably boric acid, aluminum sulfate, zirconium oxide, and aluminum hydroxide. However, other additives such as sulfuric acid, caustic soda, titanium dioxide, and others may also be used.

[0019] In the method of the present invention, a membrane separation process is also used to obtain anion-rich material stream 58 and an acidic anion-poor / alkali metal-rich material stream 60, which can be reused or used to close the loop of the manufacturing process. The material stream 58 (acid) is preferably collected in a collection tank 59.

[0020] Furthermore, concentrated water from the collection tank 55 is used as a source for the membrane separation process 61 (diffusion dialysis). 57 It is also preferable for it to be used as such.

[0021] The use of alkali metal-rich precursor 5, such as LiOH·1H2O, as a starting material favorably leads to the formation of concentrate 15 during the dehydration step 9, which is recovered and reused for the subsequent washing step.

[0022] Similarly, dehydration in unit 11 of precursor 7 produces concentrate 19, but due to its very low water content of only about 0.4% (depending on the product and quality), dehydration accounts for only a small portion of the concentrate. For integrity, concentrate 19 is also supplied to concentrate tank 55 for further use as washing water. This makes it possible to use other qualities, particularly those with higher water content. The anhydrous alkali metal oxide 13 from dehydration / drying 9, the anhydrous metal oxide mixture 17 from dehydration / drying 11, and preferably additional additives 21 are uniformly mixed, preferably in a mixing device 21 (e.g., using a high-speed mixer). Anhydrous is understood to mean technically feasible and economically viable. Thus, the smallest amount of water is CAM productIt is acceptable as long as it does not adversely affect the quality.

[0023] The homogeneous mixture 23 is subjected to a standard sequence of process steps 24 (calcination, deagglomeration, and screening / magnetic separation). These steps are known to those skilled in the art.

[0024] The present invention also relates to a process plant for carrying out the methods described above. The same features described in the process method of the present invention also apply to the process plant. In particular, refer to the list of reference numerals and Figures 1, 3, and 4.

[0025] A further subject of the present invention is the use of the above-described process plant for the production of alkali metal-containing cathode active materials.

[0026] Another subject of the present invention is the use of the aforementioned process plants for the production of acids such as sulfuric acid, phosphoric acid, nitric acid, or carbonic acid, thereby this list is not exhaustive and depends on the cathode active materials produced or the additives used, respectively. [Brief explanation of the drawing]

[0027] The present invention will be described in more detail with reference to Figure 1, which is shown below.

[0028] [Figure 1] Figure 1 is a block flow diagram of the material flow in the CAM manufacturing process according to the present invention. [Figure 2] Figure 2 shows a block flow diagram of materials in a conventional CAM manufacturing process. [Figure 3]Figure 3 shows a cascaded deformed wash water supply 47, where the materials flow at minimum alkali metal concentrations of 15, 19, and 64, respectively, with concentrated mixtures 43 and concentrates 46 positioned at the rear end of cascaded connection 47.3, followed by material flow 54 from cascaded connection 47.2, then material flows 40 and 42b from cascaded connection 47.1, from which they flow into the wash process reservoir 47.0. [Figure 4] Figure 4 shows an optional / modified solids separator 65, which includes a solid filter 49 and / or a filtrate collection tank 51 and / or a precipitate 69 and / or a decanter and / or a chamber filter press 73 and / or a concentrate collection tank 37. [Modes for carrying out the invention]

[0029] The positive electrode of a battery is often called the "cathode." In most conventional lithium-ion batteries, lithium cobalt oxide is used as the cathode. However, in recent years, many alternative material systems have been developed and are being used.

[0030] Furthermore, the rising price and declining supply of lithium are driving further development of sodium-ion batteries (NIBs). Sodium-ion batteries have high growth potential due to their superior product characteristics. While lithium has a limited supply, sodium makes up 2.6% of the Earth's crust. It is also possible to combine lithium-ion and sodium-ion technologies to create so-called hybrid batteries. The importance of NIBs is likely to increase considerably in the coming years, and the present invention, while used here, could play a decisive role in saving considerably more than lithium-ion batteries (LIBs).

[0031] However, in most cases, lithium and oxygen remain essential components of the system. Only the metallic element cobalt is often replaced, either entirely or partially, by other metallic elements such as nickel or manganese. For this reason, most lithium-ion batteries can be described as having a lithium metal oxide cathode. However, there are also systems that use lithium iron phosphate, for example, as a material.

[0032] Lithium metal oxides are produced as solid powders. When selecting a powder as a suitable material for use as a cathode in lithium-ion batteries (LIBs), the microstructure, morphology, particle size, and the degree and type of possible impurities in the powder play a decisive role. These affect the electrochemical properties of the battery that is subsequently manufactured.

[0033] In particular, energy density, which is extremely important for electric vehicles, is influenced by the structural parameters mentioned above.

[0034] Therefore, the microstructure of the cathode must be precisely controlled. This can be achieved, on the one hand, by selecting appropriate raw materials, and on the other hand, by a controlled manufacturing process for the cathode powder. As the term suggests, lithium metal oxides are mixed crystals of lithium oxide and oxides of other metals. These mixed crystals are formed by heat-treating mixtures of individual oxides at high temperatures, typically 800-1000°C under specific atmospheric conditions. The individual oxides are then provided by adding various raw materials to the mixture. The starting materials are often hydroxides or carbonates of lithium and other metal elements.

[0035] The "Synthesis Report: Cathode Active Materials for Lithium-Ion Batteries," entry ID 506108 (as of June 14, 2023: https: / / www.forschungsinformationssystem.de / ), compares the advantages and disadvantages of various cathode active materials (NMC, LFP, LCO, and LMNS). Due to the increasing importance of safety and service life in relation to the use of batteries in electric mobility, layer oxides of lithium, nickel, manganese, and cobalt (NMC) are considered one of the most suitable active materials for lithium-ion batteries. Depending on the materials and additives used, various cations (Li, Ni, Co, Mn, Fe, Al, etc.) and anions (sulfates, phosphates, carbonates, nitrates, etc.) are present in the material flow. However, the principle of the present invention is independent of this and can be used for all variations of the active material. Instead of sulfuric acid, only other acids (phosphoric acid, nitric acid, carbonic acid, etc.) are recovered.

[0036] When these starting materials are heat-treated at a temperature of 600-800°C, water (H2O) or carbon dioxide (CO2) is released, and the remaining oxides are then added to the mixed crystal through further processing.

[0037] Basically, in the production of cathodes, the first step involves obtaining various oxides from the hydroxides or carbonates of the same element, and the second step involves producing the desired mixed crystal from these oxides.

[0038] The first step, in which two solids react with each other to form a third solid and release gas, is called calcination. The second step is called sintering or solid diffusion. Calcination occurs almost instantly, regardless of time, as long as the necessary temperature and starting materials are present to initiate the reaction. As a result, the first step of heat treatment in cathode production proceeds relatively quickly. In contrast, the diffusion process for the formation of mixed crystals is highly time-dependent and requires a considerably longer time. In the latest technology, the two steps are usually carried out sequentially in a single process, but in other examples, the calcined product is first cooled and then sintered in a separate heat process.

[0039] In addition to cost and production capacity in a limited space, product quality is also a key success factor for cathode powder manufacturers. This is because, at the same price, battery manufacturers naturally prefer materials with higher energy density, for example. This can be achieved by making the most of the thermodynamic effects on the firing and sintering processes.

[0040] Figure 2 shows a simplified version of a typical manufacturing process (at the latest technology level) for such cathode materials. Intermediate steps such as screening / magnetic separation and crushing are not fully listed because the resulting small losses are negligible in representing the material flow.

[0041] The material flow, closed cycle, and especially the use of concentrated solution instead of pure deionized water, as shown in the block diagram, eliminate the need for additional deionized water. Instead of numerous wastewater streams with varying levels of contamination, there is only a single material flow with a constant concentration of dissolved ions (acid anions, alkali metal cations), and wastewater was reduced from 2.5-4 liters / kg per kg of product (CAM-cathode active material) to 0 liters / kg.

[0042] The main advantage over conventional processes is the higher concentration of recoverable and economical alkali metals (e.g., lithium).

[0043] A certain level of product quality can only be achieved through the recirculation and reuse of washing water, which is part of the present invention.

[0044] Part of the present invention involves maintaining a constant concentration of alkali metals (e.g., lithium) or alkali metal sulfates or other alkali metal compounds in the wash water supply. This makes the process controllable. The resulting constant process conditions allow for consistent product quality to be achieved. This is made possible for the first time by the present invention.

[0045] By recirculating the wash water within the storage container 47 and ensuring that the wash water contains a specified concentration of already dissolved alkali metals (e.g., lithium), undesirable redissolution of alkali metals (e.g., lithium) from the metal oxide lattice is prevented. The washing process 28 only needs to wash away any excess alkali metals (e.g., lithium) that are not stored in the lattice. These problems are known in existing plants. Solutions to these problems have not yet been found in the prior art.

[0046] The redissolution of heavy metals (Ni, Co, Mn, Fe, etc.) is not expected due to the pH range of 10-12. Therefore, these are not considered in the water quality of the wash water supply 47.

[0047] The concentration in the wash water supply 47 is limited, among other things, by solubility, particularly the solubility of alkali metals and alkali metal salts. In the case of lithium or lithium sulfate, Li2SO4 has good solubility of 342 g / L in water at 25°C. As a result, the maximum concentration of dissolved lithium is 43.18 g / L. The concentration of lithium is also determined by product quality, formulation, precursors and additives used, and other process parameters. Using the lithium-containing cathode active material NMC (lithium-nickel-manganese-cobalt) and the corresponding precursors LiOH·1H2O and Ni-Mn-Co hydroxide mixture as precursor 7, the concentration in the wash water is preferably specified as 23-25 ​​g / L.

[0048] The specified concentration of lithium or other alkali metals in the wash water supply 47 is determined considering the technical and economic operations of the subsequent processes for treating the solution and recovering the raw materials, particularly lithium (sulfate).

[0049] Part of the present invention is, in particular, the use of a solid separation 65 to enable the separation of solids from the discharged wash water 48 upstream of downstream membrane processes 53 and 61 for the recovery / concentration of alkali metal compounds. The solid separation 65 is shown in Figure 4, having possible or combinable process steps. Here, ultra reactor The filter 49 may, in particular, be used to separate solid particles, and the resulting concentrate 36 may be collected in a concentration tank 37, after which the material flow 36a may be returned to the CAM product 30. This is preferably done by proportionally mixing the material flow with the washed CAM product 30 in front of unit 32. However, proportional mixing may also be done in unit 28 where the washing process is performed. This ensures that returning the concentrate 36a to the manufacturing process does not result in the loss of products, alkali metals (e.g., lithium), etc., and does not generate an additional waste stream. Other solid / liquid separation processes, e.g., solid separation by precipitation 69 (e.g., tilt or lamellar clarification), decane Tao and / or filter press 73, or other depths and surfaces reactor Overprocessing can also be used. Various combinations of solid / liquid separation processes are also possible. The resulting solid 74 is mixed with the solid 44 in the collection tank 33 and collected.

[0050] The present invention primarily relates to the return of material flow and concentrate 36a to the process. The return of the solid-rich material flow 36a is preferably carried out by proportional mixing with the feed 30, either inside or in front of the unit 32. Return and mixing within a cleaning device 28 where the cleaning process is carried out is also conceivable.

[0051] Depending on whether the alkali metal concentration in the washing water storage container 47 is considered appropriate or necessary, for example, nano reactor The following enrichment may occur due to the excess 53. Nano reactorThe alkali metal filtration solution 54 (filtrate) generated from the filtration is returned to the wash water reservoir 47. The concentration of alkali metal salts (e.g., lithium sulfate) in the reservoir 47 is kept constant by discharging the alkali metal salt (e.g., lithium sulfate) enriched solution 48 (concentrate).

[0052] The material flows "rinse water for filter cloth washing" 40, "filtrate for solid / liquid separation" 42b, "low alkali metal solution" 54, concentrates 15, 19, 46, and 64 can also be collected separately.

[0053] One modification of the present invention, as shown in Figure 3, provides a cascaded coupling of individual material flows, where each material flow is supplied to its respective cascaded stage depending on its purity and volume. This modification of the wash water reservoir 47 includes the water inlet 34 and 38 This prevents concentration fluctuations, thereby allowing the washing process 28 to be carried out within a very narrow tolerance range. The constant concentration in the washing water reservoir also provides an advantage in the subsequent treatment of the material flows 48 and 52.

[0054] The amount of concentrate 19 from the drying / dehydration 11 of precursor 7 is so small that it can be practically ignored. However, for the sake of integrity, this is included in the present invention because there are diverse precursors having various components, varying levels of purity, and varying water content.

[0055] Part of the present invention is that the concentrate 56 from nanofiltration 53 is supplied to a membrane separation process 61 (e.g., diffusion dialysis), thereby allowing the material flow 48 from the reservoir 47 to be supplied directly to the membrane separation process or diffusion dialysis 61 without prior concentration or prior nanofiltration 53.

[0056] A semipermeable anion exchange membrane is preferably used (acid diffusion dialysis). This membrane holds alkali metal ions (e.g., lithium) while H + and SO4 2-This allows ions or acid residue anions to diffuse. This results in the formation of acid 58 in the diffused material, which is used elsewhere as a raw material. The amount of acid produced is preferably determined by volume balance and roughly corresponds to the amounts of concentrates 15 and 19 produced. In the dialysate, an alkali metal-rich solution 60 (e.g., LiOH·H2O) is recovered. This alkali metal-rich material stream 60 is preferably dehydrated using a separate unit 63, and the recovered alkali metal-rich, anhydrous precursor 62 is mixed with materials 13, 17, and 22 in the mixing unit 21 in a desired mixing ratio. The dehydration unit 63 preferably includes, among other things, a collection tank as a storage container before drying. However, proportional mixing (formulation) and dehydration may be performed in the dehydration unit 9, together with or separately from the precursor 5, as long as a high water content during mixing is not a problem.

[0057] Another component of the present invention is that the deionized water required for the membrane separation process 61 (e.g., diffusion dialysis) is preferably replaced by concentrated water 57 (15, 19, 64) from the collection tank 55, thus eliminating the need for further deionized water. The (deionized) water required for diffusion dialysis can also be replaced or mixed with concentrated water in proportion to the amount of water required.

[0058] Process description: The concentrate 15 from the dehydration 9 of preliminary product 5, the concentrate 19 from the dehydration 7 of preliminary product 7, and the concentrate 64 from the dehydration 63 of the alkali metal-rich material stream 60 from the process are collected in tank 55 and (re)used as feedstock for the washing process. The majority of the condensate comes from the drying of precursor 5, and a small portion comes from the drying of precursor 7.

[0059] After the CAM precursor 26 (e.g., Li metal oxide or Li metal oxide mixture) is generated, the reaction product is washed and filtered. Filtering is preferably performed in a chamber filter press 32 using a filter cloth, but all other filtering methods known to those skilled in the art can also be used. The filtrate 42b from the chamber filter press 32, or the washing water 38 from the washing water reservoir 47, is used to wash the filter cloth. This prevents or reduces the redissolution of alkali metals at the filter cloth / CAM product interface.

[0060] The water flows of concentrates 15, 19, and 64 are collected in the concentrate collection tank 55, while the filtrate 42 from the chamber filter press and the rinse water return 40 from the cloth wash are collected in the storage unit 47.

[0061] The filtrate 42 from the chamber filter press is initially supplied into the circuit (material flow 42a) to prevent solid-contaminated filtrate from entering the wash water reservoir at the start (filter cake formation, turbidity). Switching to the wash water tank can also be monitored and controlled by a sensor (turbidity).

[0062] The concentrations of alkali metals (e.g., lithium, sodium, etc.) and acid residue anions (e.g., sulfates, phosphates, etc.) in the wash water reservoir 47 are maintained at a nearly constant level. As expected, when LiOH·H2O is used as precursor 5, the lithium concentration settles at 23-28 g / L. This lithium concentration range has a positive effect on the wash process because it significantly reduces the undesirable redissolution of lithium. Ideally, a value of approximately 25 g / L should be achieved.

[0063] The subsequent processing and recovery of lithium or other alkali metals is facilitated by the high concentration of, for example, lithium or sodium in the feed 47.

[0064] Further concentration of the resulting alkali metal-containing solution 53 can preferably be carried out by nanofiltration or diffusion dialysis. A combination of nanofiltration and diffusion dialysis is preferred.

[0065] To avoid contamination of nanofiltration or diffusion dialysis by solid particles, solid separation 65 is performed upstream. This solid separation, like other solid separation processes, may include microfiltration and / or ultrafiltration.

[0066] For example, as described in European Patent No. 2762611, further treatment of lithium sulfate to obtain lithium oxide monohydrate may be carried out.

[0067] The solid-rich solution 36 from the solid filter 49 (e.g., microfiltration or ultrafiltration) is preferably subjected to a subsequent step, for example, precipitation 69 by a lamellar clarifier, or simply a thickener. e (ner) and subsequent chamber filter press (CFP) or decanting Ta7 In Figure 4, the material flow 36b may be further concentrated. The solid (e.g., filter cake) 74 may be supplied as a product according to customer specifications, for example, by mixing and preparing (mixing product and off-spec). However, it is preferable to collect the solid-rich concentrate 36 from the solid separator 65 in the tank 37 and mix it proportionally with the feed material 30 as the feed material 36a in the device 32.

[0068] This can be done in stages. Since the residual volume is very small, the recovery of alkali metals, especially lithium, such as lithium hydroxide monohydrate or other lithium or alkali metal compounds, can also be done externally.

[0069] The process, particularly the material flow, is a practical invention that enables a closed-loop process in the manufacturing of cathode-active materials, resulting in virtually no losses. Additional resources such as deionized water, raw materials, and chemicals for pH correction are not required.

[0070] The formulations and precursors used may differ from those shown. Additives and precursors will vary depending on customer requirements.

[0071] The present invention offers the following advantages: • Stable and extremely high product quality • A controlled process (the sensitivity of the cleaning process is no longer an issue, given the current level of technology). • No additional resources (water, wastewater treatment chemicals, etc.) are required. • 100% of the raw materials used become part of the final product, with no waste of raw materials. • No waste, wastewater, or sludge is generated. • No need for high plant investments, such as evaporation plants for concentrated wastewater (e.g., lithium-concentrated wastewater). • Since there is no need to discharge wastewater, it does not violate discharge limits.

[0072] Cost reduction as a result of the present invention: A. Recovery of alkali metals (especially lithium) or precursors by closing the cycle. B. Decommissioning of other facilities such as wastewater treatment plants or evaporation plants. C. No wastewater treatment / discharge costs. D. No waste / concentrate disposal costs. E. Recovery of raw material acid (e.g., sulfuric acid) F. 100% reduction in deionized water demand. G. No additional cost for pH adjusting acids / alkalis. Based on the prices of raw materials, etc. in H2023, CAM product Savings of approximately 2,000 euros per ton are achieved compared to the current state of technology.

[0073] The listed points, using lithium cathode active material as an example, result in an estimated total savings of approximately €2,000 per ton of CAM, with point A achieving the highest savings, followed by point B. [Explanation of Symbols]

[0074] List of reference numbers 1. Supply tank for alkali metal-containing precursor 5 3. Supply tank for precursor 7 5. Alkali metal precursors / alkali metal compounds thing 7 Metal oxide mixture precursors / metal compounds (Multiple options are possible) 9. Dehydration / drying equipment for precursor 5 11. Dehydration / drying equipment for precursor 7 13 Anhydrous alkali metal oxides 15. Concentrate from drying / dehydrating precursor 5 17 Anhydrous metal oxide mixture 19. Concentrate obtained by drying / dehydrating precursor 7 21 Mixing Unit 22 Additive storage container 23 Homogeneous mixture 24. Generation of Me-Oxide lattices and Li intercalations via calcination, crushing, and sieving / magnetic separation. 26 CAM precursor 28 Washing preparation CAM product 30 CAM product after washing 32 Solid / Liquid Separation Devices 33 Solid CAM Collection Tank 34 Washing water 36. Solid-rich solution (concentrate) 36x a = recirculation, b = further concentration 37. Concentrate / Solid Collection Tank 38. Washing water for filter cleaning 40. Rinse water for filter cleaning 42 Filtration solid / liquid separation (a=turbid flow, b=clear flow) 43 Concentrated mixture 44. Solids (e.g., filter cake, CAM product for drying) 45 Drying / dehydration equipment (for example, Filtered cake ) 46 Concentrated water from drying 45 47 Washing water storage unit 47.x Examples of cascaded wash water reservoirs 47.0~47.3 48. Filter for supplying solids (e.g., ultrafiltration) 49. Solid filters (e.g., ultrafiltration) 50 Solid-free or low-solids solutions (permeates) 51 Filtrate collection tank 52. Solid-free solution (supply raw material 53) 53 Concentration Unit 54 Alkali metal plutonium solution 55 Concentrated water collection tank 56 Alkali metal-rich solution from the concentration unit 57 Concentrated water 58 Anion-Rich Material Flow (Acid) 59 Acid Tank 60 Alkali Metal Rich Materials Flow 61. Membrane separation processes (e.g., diffusion dialysis) 62. Recovered alkali metal-rich precursor products 63 Dehydration Unit 64. Concentrates from dehydration 65 Solid Separator 68 Clear phase, transparent phase with low solid content 69. Sedimentation (e.g., lamellar purifier) 70 Precipitate, high solids content 72 Solid-free or low-solids solutions from solid filters 73. Solid / Liquid Separation (e.g., KFP and / or Decanter) 74 Solids from Unit 73 (e.g., filter cake)

Claims

1. A method for producing an alkali metal-containing cathode material, wherein the method is a) The step of providing one or more metal compounds (7) in (3), b) The step of providing the alkali metal compound (5) in (1), c) Dehydrating / drying the alkali metal compound (5) in unit (9) and dehydrating the metal compound (7) in unit (11), and / or dehydrating / drying the recovered alkali metal-rich product (60) preferably in unit (63) or alternatively in unit (9), separating the resulting concentrates (15) and / or (19) and / or (64), collecting them in a concentrate tank (55), leaving the concentrates (15) and / or (19) and / or (64) and / or the concentrated mixture (43), and using the concentrates (15) and / or (19) and / or (64) and / or the concentrated mixture (43) as wash water (34) for the washing process and wash water (38) for the washing filter unit (32), d) A step in which a metal oxide lattice is manufactured in unit (24) and an alkali metal is incorporated, e) a method comprising washing the CAM precursor (26) obtained from step d) with the washing water (34) from the storage container (47) derived from step c), and separating the washed CAM product (30) into a solid / liquid via a unit (32) to separate it into a filtrate (42) and a solid (44).

2. The method according to claim 2, wherein the washing water (48) from step f) is passed through a solid separator (65), and the resulting solid-free solution or solid-poor solution (50) and / or (68) and / or (72) and the obtained solid-rich concentrate (36) are collected in a tank (37) and proportionally mixed with feed (30) as feed (36a) in a device (32), and / or mixed with feed (36) in a device (32) in proportion to feed (30), and / or mixed as feed (36b) using precipitation (69) and / or solid / liquid separation (73) (e.g., chamber filter press), and preferably mixed as solid (74) with solid (44) in a collection tank (33).

3. The method according to claim 3, wherein the solid-free solution is subjected to a concentration unit (53) and / or a membrane separation process (61), so that the alkali metal-poor solution (54) from the concentration unit (53) is supplied to the wash water reservoir (47) and an alkali metal-rich solution (56) or (60) is separated.

4. The method according to claim 4, wherein the alkali metal-rich solution (56) is subjected to a membrane separation process (61) to obtain an alkali metal-rich material stream (60), the material stream (60) is dehydrated, the dehydrated alkali metal precursor (62) is preferably mixed in the mixing unit (21) with anhydrous alkali metal oxide (13) and / or additive (22) in a desired mixing ratio, and the concentrate (64) is supplied from the dehydration unit (63) and / or (9) to a concentrate collection tank (55), from which it is supplied to the wash water storage unit (47).

5. The method according to any one of the preceding claims, wherein the unit (32) for solid / liquid separation in step e is performed by a chamber filter press, the filtrate (42a) is preferably circulated first, the turbidity is preferably monitored and controlled by a sensor, the filtrate (42b) is supplied to the reservoir (47) during the cleaning operation, and the rinse water (40) generated during the washing of the filter cloth is supplied to the wash water reservoir (47).

6. The method according to any one of the preceding claims, wherein the concentrations (38) and (48) of the alkali metal and / or acid residue anions in the wash water storage (47) and the extraction / inlet (34) are maintained constant by recovery (48) and recirculation of the treated wash water (54) and / or concentrated water (43) and / or (46), the concentrations can be adjusted as desired depending on the CAM product and process parameters, and the concentrations are selected such that redissolution in the wash and rinse processes is kept as low as possible and precipitation of the components is prevented.

7. The precursor (5) is lithium oxide monohydrate (LiOH·1H ２ O) The method according to any one of the prior claims.

8. The method according to any one of the preceding claims, wherein the metal compound comprises a metal selected from Ni, Mn, Co, Al, Zn, Fe, or a mixture thereof.

9. The method according to any one of the preceding claims, wherein each of the material flows (40) includes (40) and (42b) flowing from a solid / liquid separator (32), concentrate (43) flowing from a collection tank (55) or directly from (9), (11) and (63), (46) flowing from the drying unit (45), (54) flowing from the concentration unit (53), and is supplied in a cascading manner to a wash water supply device (47).

10. The method according to claim 9, wherein nanofiltration is preferably used as a concentration unit (53).

11. The method according to any one of the preceding claims, wherein an acid (58) is collected in a tank (59), and a material stream (60) with low acid anions and rich in alkali metals is recovered for reuse / circuit closure by a membrane separation process (61).

12. The method according to claim 11, wherein a semipermeable membrane or an ion exchange membrane is used.

13. The method according to any one of the preceding claims, wherein the concentrated mixture from the collection tank (55) is used as a feed (57) for the membrane separation process (61).

14. A process plant for performing the method according to any one of claims 1 to 13.

15. Use of the process plant according to claim 14 for the production of alkali metal-containing cathode materials and / or the recovery of an acid selected from sulfuric acid, phosphoric acid, nitric acid, and / or carbonic acid.

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