Method for preferentially extracting lithium from battery black powder

Abstract

The invention provides a method for preferentially extracting lithium from battery black powder, and relates to the field of battery recovery. The method comprises the following steps: mixing battery black powder with water and acid liquor, carrying out lithium extraction reaction on the battery black powder under the conditions of pressurization and heating to obtain reacted slurry, and carrying out solid-liquid separation to obtain a lithium-rich solution and residues; the battery black powder comprises at least one of waste ternary lithium ion battery positive electrode powder, waste ternary lithium ion battery positive and negative electrode mixed powder and waste lithium iron phosphate battery black powder. According to the method for preferentially extracting the lithium from the battery black powder, operation steps are simplified, energy consumption is reduced, efficient and preferential recovery of the lithium is achieved, the recovery rate of the lithium and the separation efficiency of the lithium and nickel / cobalt / manganese are remarkably improved, the lithium leaching rate can reach 96.5% or above, and the nickel-cobalt-manganese leaching rate is lt; and 0.5%.

Description

Technical Field

[0001] The present application relates to the field of battery recycling, and in particular to a method for preferentially extracting lithium from battery black powder. Background Art

[0002] Lithium-ion batteries are widely used in electric vehicles, energy storage systems and portable electronic devices due to their high energy density and long cycle life. As the use of lithium batteries continues to increase, the recycling of waste lithium batteries and the reuse of metal resources have gradually become the focus of global attention. Lithium battery positive electrode materials contain high-value metal resources such as lithium, nickel, cobalt, and manganese. Among them, the recycling of lithium is particularly important because it is the core metal in the battery, the supply is limited, and the market demand is growing.

[0003] The traditional method of recycling positive electrode materials for lithium batteries usually dissolves all metals into the solution through acid leaching, and then separates the metals through an extraction process. Acid leaching usually uses acids such as sulfuric acid or hydrochloric acid to leach metals such as nickel, cobalt, manganese, and lithium together, and then selectively separates the metals through different extractants. This method is technically mature, but due to the coexistence of multiple metals, the separation process is complicated and costly, especially when extracting lithium, it often interferes with the complex coexistence system of nickel, cobalt, and manganese, resulting in low lithium recovery efficiency.

[0004] Prioritizing the extraction of lithium is an important measure to effectively improve the separation efficiency of lithium and nickel / cobalt / manganese, and the recovery rate of valuable metals. The sulfate (or sulfuric acid) roasting-water leaching process can convert the lithium in the positive electrode material into a soluble compound through the roasting process, thereby preferentially extracting lithium in the water leaching step. This method uses physical and chemical transformations to form different compound states of lithium and other metals to achieve selective extraction of lithium. However, this process requires high-temperature roasting, and roasting with sulfuric acid is prone to sulfur dioxide pollution. Roasting with sulfate has problems such as the introduction of impurity ions, and the energy consumption is high, and the process flow is relatively complicated. Therefore, how to break through the limitations of traditional processes and provide a more economical and operational technical path for the recovery of lithium battery positive electrode materials has become a technical problem with a lacing solution. Summary of the invention

[0005] The purpose of this application is to provide a method for preferentially extracting lithium from battery black powder to solve the above-mentioned problems.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] The present application provides a method for preferentially extracting lithium from battery black powder, comprising: mixing battery black powder with water and acid solution, subjecting the battery black powder to a preferential lithium extraction reaction under pressurized and heated conditions to obtain a post-reaction slurry, and performing solid-liquid separation to obtain a lithium-rich solution and a residue;

[0008] The battery black powder includes at least one of waste ternary lithium-ion battery positive electrode powder, waste ternary lithium-ion battery positive and negative electrode mixed powder, and waste lithium iron phosphate battery black powder.

[0009] Optionally, the heating temperature in the preferential lithium extraction reaction is 120°C-300°C, and the heating time is 0.5h-10h.

[0010] Optionally, the pressurized pressure in the preferential lithium extraction reaction is 0.2-8.7 MPa.

[0011] Optionally, the corresponding relationship between the water and the battery black powder is that every 1g of the battery black powder corresponds to 1-30mL of water.

[0012] Optionally, calculated based on the amount of hydrogen ions in the acid solution, the amount of hydrogen ions in the acid solution is 1-1.5 times the amount of lithium ions in the battery black powder.

[0013] Optionally, the acid solution includes an organic acid and / or an inorganic acid;

[0014] The inorganic acid includes sulfuric acid, hydrochloric acid, and nitric acid; the organic acid includes acetic acid, tartaric acid, and citric acid.

[0015] Optionally, the endpoint pH value of the slurry after the reaction is 5.0-8.5.

[0016] Optionally, the battery black powder is obtained by discharging, disassembling, crushing, screening and drying the waste batteries.

[0017] Optionally, the screening includes removing the current collector of the used battery using a first reagent; the first reagent includes N-methylpyrrolidone.

[0018] Optionally, the battery black powder may be pretreated, and the pretreatment includes at least one of direct calcination defluorination, auxiliary agent calcination defluorination, and vacuum pyrolysis fluorine fixation.

[0019] Compared with the prior art, the beneficial effects of this application include:

[0020] The present application provides a method for preferentially extracting lithium from battery black powder. This method allows lithium to be dissolved in the solution with higher selectivity by acid leaching under a pressurized environment, thereby avoiding the interference of mixed leaching of other metals such as nickel, cobalt, and manganese. On the one hand, the operating steps are simplified, the process flow is simple, and efficient priority recovery of lithium is achieved, thereby improving the recovery efficiency of lithium; on the other hand, the battery black powder used in this method comes from waste batteries and has a high value. By recycling these metal elements, not only can the mining of new resources be reduced, but also the production cost of new batteries can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0022] Figure 1 A schematic flow chart of a method for preferentially extracting lithium from battery black powder provided in an embodiment. DETAILED DESCRIPTION

[0023] As used herein:

[0024] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0025] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0026] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0027] In these examples, parts and percentages are by mass unless otherwise indicated.

[0028] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0029] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0030] In order to better explain the technical solution provided by this application, an overall statement of the technical solution is first made before the embodiments.

[0031] The present application provides a method for preferentially extracting lithium from battery black powder. For ease of understanding, the technical solution of the present application is described below.

[0032] The method for preferentially extracting lithium from battery black powder provided in the present application comprises: mixing battery black powder with water and acid solution, subjecting the battery black powder to a preferential lithium extraction reaction under pressurized and heated conditions to obtain a post-reaction slurry, and performing solid-liquid separation to obtain a lithium-rich solution and a residue;

[0033] The battery black powder includes at least one of waste ternary lithium-ion battery positive electrode powder, waste ternary lithium-ion battery positive and negative electrode mixed powder, and waste lithium iron phosphate battery black powder.

[0034] It is understandable that the battery black powder can be purchased directly, or obtained by discharging, disassembling, crushing and separating waste ternary lithium-ion batteries or waste lithium iron phosphate batteries. The main active positive electrode materials obtained after disassembly are also some negative electrode carbon materials. The waste ternary lithium-ion batteries can be single lithium-ion batteries containing any one of nickel, cobalt and manganese or binary lithium-ion batteries containing any two of them, and can also be ternary lithium-ion batteries containing nickel / cobalt / manganese or nickel-cobalt-aluminum.

[0035] It should also be noted that the battery black powder can also be replaced by battery positive electrode powder, which mainly comes from unqualified products produced in the production process of positive electrode materials.

[0036] In an optional embodiment, the heating temperature in the preferential lithium extraction reaction is 120°C-300°C, and the time is 0.5h-10h. The present application utilizes the difference in reaction rates between acid and various metal oxides at high temperatures and the characteristics of high temperature hydrolysis of metal ions to significantly improve the extraction efficiency and selectivity of preferential lithium extraction.

[0037] Optionally, the heating temperature in the preferential lithium extraction reaction can be 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, or any value between 120-300°C. Optionally, the heating temperature in the limited lithium extraction reaction can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, or any value between 0.5-10h.

[0038] In an optional embodiment, the pressurized pressure in the preferential lithium extraction reaction is 0.2-8.7 MPa.

[0039] Optionally, the pressure applied during the preferential lithium extraction reaction may be 0.2 MPa, 1.5 MPa, 2.1 MPa or 5 MPa.

[0040] In an optional embodiment, the corresponding relationship between the water and the battery black powder is that every 1g of the battery black powder corresponds to 1-30mL of water.

[0041] Optionally, the amount of water corresponding to every 1g of the battery black powder may be 1mL, 2mL, 3mL, 4mL, 5mL, 6mL, 7mL, 8mL, 9mL, 10mL, 11mL, 12mL, 13mL, 14mL, 15mL, 16mL, 17mL, 18mL, 19mL, 20mL, 21mL, 22mL, 23mL, 24mL, 25mL, 26mL, 27mL, 28mL, 29mL, 30mL, or the amount of water corresponding to every 1g of the battery black powder may be any value between 1-30mL.

[0042] In an optional embodiment, calculated based on the amount of hydrogen ions in the acid solution, the amount of hydrogen ions in the acid solution is 1-1.5 times the amount of lithium ions in the battery black powder.

[0043] Optionally, the amount of hydrogen ions in the acid solution may be any value between 1 and 1.5 times the amount of lithium ions in the battery black powder. It is understood that the amount of hydrogen ions per 1 mol of lithium ions may be 1 mol, 1.1 mol, 1.2 mol, 1.3 mol, 1.4 mol, 1.5 mol, or the amount of hydrogen ions per 1 mol of lithium ions may be any value between 1 and 1.5 mol.

[0044] In an optional embodiment, the acid solution includes organic acid and / or inorganic acid; the inorganic acid includes sulfuric acid, hydrochloric acid, nitric acid; the organic acid includes acetic acid, tartaric acid, citric acid.

[0045] In an optional embodiment, the endpoint pH value of the slurry after the reaction is 5.0-8.5. In the method provided in the present application, the battery black powder is treated by pressurized acid leaching. By precisely controlling the temperature and the endpoint acidity, lithium is preferentially allowed to enter the solution in the form of ions. Nickel / cobalt / manganese is first leached, and then as the reaction time increases, a hydrolysis reaction occurs to generate the corresponding hydroxide or oxide solids and remain in the nickel / cobalt / manganese slag. The process selectivity is strong during the reaction process, which significantly improves the recovery rate of lithium and the separation efficiency of lithium from nickel / cobalt / manganese. The lithium leaching rate can reach more than 96.5%, and the nickel-cobalt-manganese leaching rate is <0.5%. Subsequently, only some ions need to be removed to meet the requirements for preparing a precursor solution of battery-grade lithium carbonate. This method has strong economy and operability, and is conducive to industrial promotion and application.

[0046] Optionally, the endpoint pH value of the slurry after the reaction can be 5.0, 5.2, 5.4, 5.6, 5.8, 6, 6.2, 6.4, 6.6, 6.8, 7, 7.2, 7.4, 7.6, 7.8, 8, 8.2, 8.4, 8.5, or any value between 5.0 and 8.5.

[0047] In an optional embodiment, the battery black powder is obtained by discharging, disassembling, crushing, screening and drying the waste batteries.

[0048] In an optional embodiment, the screening includes removing the current collector of the used battery using a first reagent; the first reagent includes N-methylpyrrolidone.

[0049] In an optional embodiment, the battery black powder may be pretreated, and the pretreatment includes at least one of direct calcination defluorination, auxiliary agent calcination defluorination, and vacuum pyrolysis fluorine fixation.

[0050] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0051] Example 1

[0052] like Figure 1 As shown, this embodiment provides a method for preferentially extracting lithium from battery black powder, and the specific steps are as follows:

[0053] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries were discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets were crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive electrode powder. The main element composition analysis is shown in Table 1:

[0054] Table 1 Elemental composition of battery black powder used in Example 1

[0055] Element Li Ni Co Mn content 6.54 43.86 4.9 4.56

[0056] (2) Weigh 100 g of battery black powder, add 300 mL of pure water, add 50 g of sulfuric acid with a mass fraction of 98%, the reaction temperature is 230° C., the reaction pressure is 2.8 MPa, the reaction time is 150 min, and after cooling, the solid-liquid separation is performed to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0057] The leaching rate of lithium ions in the lithium-rich solution was measured to be 97.15%. The lithium ion concentration in the lithium-rich solution was 16.66 g / L, the nickel ion concentration was 0.92 g / L, the cobalt ion concentration was 0.81 mg / L, and the manganese concentration was 0.08 mg / L. Nickel, cobalt, and manganese were almost not leached.

[0058] Example 2

[0059] This embodiment provides a method for preferentially extracting lithium from battery black powder, and the specific steps are as follows:

[0060] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries are discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets are crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive and negative electrode mixed powders. The main element composition analysis is shown in Table 2:

[0061] Table 2 Elemental composition of battery black powder used in Example 2

[0062] Element Li Ni Co Mn content 6.30 31.57 6.6 15.57

[0063] (2) Weigh 100 g of battery black powder, add 400 mL of pure water, add 100 mL of concentrated hydrochloric acid with a mass fraction of 36%, the reaction temperature is 260° C., the reaction pressure is 4.7 MPa, the reaction time is 180 min, and after cooling, the solid-liquid separation is performed to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0064] The leaching rate of lithium ions in the lithium-rich solution was measured to be 97.89%. The lithium ion concentration in the lithium-rich solution was 15.04 g / L, the nickel ion concentration was 198 mg / L, the cobalt ion concentration was 18 mg / L, and the manganese concentration was 616 mg / L. Nickel, cobalt, and manganese were hardly leached.

[0065] Example 3

[0066] This embodiment provides a method for preferentially extracting lithium from battery black powder, and the specific steps are as follows:

[0067] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries were discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets were crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive and negative electrode mixed powders. The main element composition analysis is shown in Table 3:

[0068] Table 3 Elemental composition of battery black powder used in Example 3

[0069] Element Li Ni Co Mn content 5.89 29.84 7.6 15.30

[0070] (2) Weigh 100 g of battery black powder, add 600 mL of pure water, add 30 mL of anhydrous acetic acid with a mass fraction of 99.5%, the reaction temperature is 160° C., the reaction pressure is 0.62 MPa, the reaction time is 120 min, and after cooling, the solid-liquid separation is performed to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0071] The leaching rate of lithium ions in the lithium-rich solution was measured to be 95.24%, the lithium ion concentration in the lithium-rich solution was 12.17 g / L, the nickel ion concentration was 0.69 g / L, the cobalt ion concentration was 62 mg / L, and the manganese concentration was 130 mg / L.

[0072] Example 4

[0073] This embodiment is an improvement on the basis of embodiment 1, and provides a method for preferentially extracting lithium from battery black powder, and the specific steps are as follows:

[0074] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries are discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets are crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive electrode powder.

[0075] (2) The battery black powder obtained in step (1) is directly calcined for defluorination at a temperature of 450°C and a calcination time of 5 h.

[0076] (3) Weigh 100 g of battery black powder that has been directly calcined and defluorinated, add 300 mL of pure water, add 26 g of sulfuric acid with a mass fraction of 98%, the reaction temperature is 230° C., the reaction pressure is 2.80 MPa, the reaction time is 150 min, and after cooling, the solid and liquid are separated to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0077] The leaching rate of lithium ions in the lithium-rich solution was measured to be 94.94%. The lithium ion concentration in the lithium-rich solution was 14.20 g / L, the nickel ion concentration was 0.46 g / L, the cobalt ion concentration was 216.1 mg / L, and the manganese concentration was 16 mg / L. Nickel, cobalt, and manganese were almost not leached.

[0078] Example 5

[0079] This embodiment is an improvement on the basis of embodiment 1, and provides a method for preferentially extracting lithium from battery black powder, and the specific steps are as follows:

[0080] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries are discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets are crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive electrode powder.

[0081] (2) The battery black powder obtained in step (1) is subjected to auxiliary agent roasting defluorination, the auxiliary agent used is calcium oxide, the roasting temperature is 450°C, and the roasting time is 5 hours.

[0082] (3) Weigh 100 g of battery black powder that has been directly calcined and defluorinated, add 300 mL of pure water, add 26 g of sulfuric acid with a mass fraction of 98%, the reaction temperature is 230° C., the reaction pressure is 2.83 MPa, the reaction time is 150 min, and after cooling, the solid and liquid are separated to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0083] The leaching rate of lithium ions in the lithium-rich solution was measured to be 95.34%. The lithium ion concentration in the lithium-rich solution was 15.10 g / L, the nickel ion concentration was 0.73 g / L, the cobalt ion concentration was 10.1 mg / L, and the manganese concentration was 35.9 mg / L. Nickel, cobalt, and manganese were almost not leached.

[0084] Example 6

[0085] This embodiment is an improvement on the basis of embodiment 1, and provides a method for preferentially extracting lithium from battery black powder, and the specific steps are as follows:

[0086] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries are discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets are crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive electrode powder.

[0087] (2) Weigh 100 g of battery black powder, add 300 mL of pure water, add 30 g of glacial acetic acid with a mass fraction of 99.5, the reaction temperature is 210 ° C, the reaction pressure is 1.95 MPa, the reaction time is 150 min, and after cooling, the solid and liquid are separated to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0088] The leaching rate of lithium ions in the lithium-rich solution was measured to be 94.92%. The lithium ion concentration in the lithium-rich solution was 13.98 g / L, the nickel ion concentration was 0.48 g / L, the cobalt ion concentration was 13.2 mg / L, and the manganese concentration was 17.3 mg / L. Nickel, cobalt, and manganese were almost not leached.

[0089] Example 7

[0090] This embodiment is an improvement on the basis of embodiment 1, and provides a method for preferentially extracting lithium from battery black powder, and the specific steps are as follows:

[0091] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries are discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets are crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive electrode powder.

[0092] (2) Weigh 100 g of battery black powder, add 300 mL of pure water, add 26 g of sulfuric acid with a mass fraction of 98%, the reaction temperature is 230° C., the reaction pressure is 2.80 MPa, the reaction time is 10 h, and after cooling, the solid and liquid are separated to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0093] The leaching rate of lithium ions in the lithium-rich solution was measured to be 97.56%. The lithium ion concentration in the lithium-rich solution was 16.72 g / L, the nickel ion concentration was 0.99 g / L, the cobalt ion concentration was 12 mg / L, and the manganese concentration was 1.92 mg / L. Nickel, cobalt, and manganese were almost not leached.

[0094] Comparative Example 1

[0095] This comparative example uses the same nickel / cobalt / manganese ternary battery as in Example 1, and provides a method for treating battery black powder, comprising:

[0096] (1) Waste nickel / cobalt / manganese ternary batteries are discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets are crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive electrode powder.

[0097] (2) Weigh 100 g of battery black powder and 120 g of nickel sulfate hexahydrate, calcine them at 850° C. for 6 h in an argon protective atmosphere, and obtain calcined sand after cooling.

[0098] (3) After grinding the roasted sand obtained in step (2) to 200 mesh, weighing 60 g of the roasted sand and adding 240 mL of water, soaking the mixture in water at room temperature, stirring for 2 h, and then performing solid-liquid separation to obtain a lithium-rich solution and solid slag.

[0099] In the water leaching process of step (3) of this comparative example, the leaching rate of lithium ions was 98.95%, the leaching rate of nickel ions was 4.28%, the leaching rate of cobalt ions was 1.01%, and the leaching rate of manganese ions was 14.35%.

[0100] Comparative Example 2

[0101] This comparative example uses the same nickel / cobalt / manganese ternary battery as in Example 1, and provides a method for treating battery black powder, comprising:

[0102] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries are discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets are crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive electrode powder.

[0103] (2) Weigh 100 g of battery black powder, add 300 mL of pure water, the reaction temperature is 230 ° C, the reaction pressure is 2.9 MPa, the reaction time is 150 min, and the solid-liquid separation is performed after cooling to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0104] The leaching rate of lithium ions in the lithium-rich solution was measured to be 2%, the lithium ion concentration in the lithium-rich solution was 0.56 g / L, the nickel ion concentration was 0.05 g / L, the cobalt ion concentration was 0.01 mg / L, and the manganese concentration was 0.07 mg / L.

[0105] Comparative Example 3

[0106] This comparative example uses the same nickel / cobalt / manganese ternary battery as in Example 1, and provides a method for treating battery black powder, comprising:

[0107] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries are discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets are crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive electrode powder.

[0108] (2) Weigh 100 g of battery black powder, add 300 mL of pure water, add 50 g of sulfuric acid with a mass fraction of 98%, the reaction temperature is 100° C., the reaction time is 150 min, and after cooling, the solid and liquid are separated to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0109] The leaching rate of lithium ions in the lithium-rich solution was measured to be 36.1%, the lithium ion concentration in the lithium-rich solution was 4.2 g / L, the nickel ion concentration was 7.5 g / L, the cobalt ion concentration was 2.3 g / L, and the manganese concentration was 4.5 g / L.

[0110] Comparative Example 4

[0111] This comparative example uses the same nickel / cobalt / manganese ternary battery as in Example 1, and provides a method for treating battery black powder, comprising:

[0112] (1) Waste nickel / cobalt / manganese ternary lithium-ion batteries are discharged and disassembled to obtain positive electrode sheets. The positive electrode sheets are crushed and dissolved in N-methylpyrrolidone to remove the current collector, and then washed and dried to obtain battery black powder containing positive electrode powder.

[0113] (2) Weigh 100 g of battery black powder, add 300 mL of pure water, add 50 g of sulfuric acid with a mass fraction of 98%, the reaction temperature is 230° C., the reaction time is 15 h, and after cooling, the solid-liquid separation is performed to obtain a lithium-rich solution and a nickel / cobalt / manganese residue.

[0114] The leaching rate of lithium ions in the lithium-rich solution was measured to be 97.86%, the lithium ion concentration in the lithium-rich solution was 16.72 g / L, the nickel ion concentration was 0.97 g / L, the cobalt ion concentration was 34 mg / L, and the manganese concentration was 29 mg / L.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0116] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A method for preferentially extracting lithium from battery black powder, characterized in that: include: Mixing battery black powder with water and acid solution, subjecting the battery black powder to a preferential lithium extraction reaction under pressurized and heated conditions to obtain a post-reaction slurry, and performing solid-liquid separation to obtain a lithium-rich solution and a residue; The battery black powder includes at least one of waste ternary lithium-ion battery positive electrode powder, waste ternary lithium-ion battery positive and negative electrode mixed powder, and waste lithium iron phosphate battery black powder.

2. The method for preferentially extracting lithium from battery black powder according to claim 1, characterized in that: The heating temperature in the preferential lithium extraction reaction is 120° C.-300° C., and the heating time is 0.5 h-10 h.

3. The method for preferentially extracting lithium from battery black powder according to claim 1, characterized in that: The pressure applied in the preferential lithium extraction reaction is 0.2-8.7 MPa.

4. The method for preferentially extracting lithium from battery black powder according to claim 1, characterized in that: The corresponding relationship between the water and the battery black powder is that every 1g of the battery black powder corresponds to 1-30mL of water.

5. The method for preferentially extracting lithium from battery black powder according to claim 1, characterized in that: Calculated based on the amount of hydrogen ions in the acid solution, the amount of hydrogen ions in the acid solution is 1-1.5 times the amount of lithium ions in the battery black powder.

6. The method for preferentially extracting lithium from battery black powder according to claim 5, characterized in that: The acid solution includes organic acid and / or inorganic acid; The inorganic acid includes sulfuric acid, hydrochloric acid, and nitric acid; the organic acid includes acetic acid, tartaric acid, and citric acid.

7. The method for preferentially extracting lithium from battery black powder according to claim 1, characterized in that: The endpoint pH value of the slurry after the reaction is 5.0-8.

5.

8. The method for preferentially extracting lithium from battery black powder according to any one of claims 1 to 7, characterized in that: The battery black powder is obtained by discharging, disassembling, crushing, screening and drying the waste batteries.

9. The method for preferentially extracting lithium from battery black powder according to claim 8, characterized in that: The screening includes using a first reagent to remove the current collector of the waste battery; the first reagent includes N-methylpyrrolidone.

10. The method for preferentially extracting lithium from battery black powder according to claim 8, characterized in that: The battery black powder may also be pretreated, and the pretreatment includes at least one of direct calcination defluorination, auxiliary agent calcination defluorination, and vacuum pyrolysis fluorine fixation.

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