Device and method for preparing ternary precursor from waste lithium ion battery

Abstract

The application discloses a device for preparing ternary precursors from waste lithium ion batteries, which comprises at least one pre-melting kettle, a reaction kettle, a pre-filter, a fine filter, at least one washing tank, a homogenizing kettle, a homogenizing kettle pre-filter, a homogenizing kettle fine filter, a coarse product tank and a spray dryer. The device for preparing ternary precursors from waste lithium ion batteries has the advantages of simple structure, low energy consumption and high selectivity to transition metal elements. The application also provides a method for preparing ternary precursors from waste lithium ion batteries, which has the advantages of green environmental protection and selective lithium extraction through the step of low eutectic solvent leaching, realizes the recycling of solvents and the separation of lithium and heavy metals, and is conducive to the subsequent efficient recovery of lithium.

Description

Technical Field

[0001] This invention relates to the field of waste lithium-ion battery recycling technology, specifically to an apparatus and method for preparing ternary precursors from waste lithium-ion batteries. Background Technology

[0002] Lithium-ion batteries possess advantages such as high operating voltage, high specific energy, large capacity, fast charging and discharging, good cycle performance, light weight, and small size. They represent modern high-performance batteries and, since their commercialization in the 1990s, have gradually replaced other batteries, finding widespread application in mobile phones, laptops, portable electronic devices, electric bicycles, and other fields. Lithium-ion batteries, such as ternary lithium batteries, lithium cobalt oxide batteries, and lithium manganese oxide batteries, are rich in valuable metals and have high recycling value. However, retired lithium-ion batteries, as metal composite devices, are characterized by high compositional complexity and high pollution levels, posing significant challenges to their clean and efficient recycling.

[0003] Currently, the main methods for recycling spent lithium-ion batteries include pyrometallurgical recycling and wet recycling. Pyrometallurgical recycling essentially involves chemically reducing and roasting the lithium-ion batteries, then dissolving the remaining materials in a strong acid solution after high-temperature heating, and finally extracting the residue. This method boasts a recovery rate as high as 90%, but it consumes a lot of energy and releases polluting gases during the process, hindering its widespread adoption. Wet recycling involves crushing, sorting, and pre-treating the spent battery packs to obtain positive electrode powder, followed by reduction and acid leaching to recover metal elements. Existing processes have largely achieved efficient recovery of valuable metals such as nickel, cobalt, and manganese. This method has lower energy consumption, but it typically uses corrosive solvents, posing a serious threat to the environment and human health.

[0004] CN115347266A discloses a wet crushing and recycling method and apparatus for waste lithium-ion batteries. The method involves crushing waste lithium-ion batteries in a solution, followed by hydrodynamic separation, filtration, wet ball milling and screen separation, and then vacuum distillation and volatilization to obtain black powder. However, this method suffers from problems such as dust and electrolyte volatilization, as well as a lengthy recycling process, complex equipment, and a heavy burden on wastewater treatment. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of low recycling rate, high energy consumption and environmental pollution in the existing technology, and to provide an apparatus and method for preparing ternary precursors from waste lithium-ion batteries. The apparatus and method of this invention have the advantages of high recycling rate, low energy consumption and environmental protection.

[0006] To achieve the above objective, an apparatus for preparing ternary precursors from spent lithium-ion batteries is provided, the apparatus comprising:

[0007] At least one pre-melting vessel is used to dissolve the solvent to form a liquid solvent;

[0008] A reaction vessel, connected to the pre-melting vessel, is used to leach waste lithium-ion battery black powder with liquid solvent from the pre-melting vessel to obtain a solid-liquid mixture;

[0009] A pre-filter, connected to the reaction vessel, is used for preliminary filtration of the solid-liquid mixture;

[0010] A fine filter, connected to the pre-filter, is used to perform fine filtration on the liquid phase after preliminary filtration by the pre-filter;

[0011] At least one rinsing tank, connected to the pre-filter and the fine filter, is used to wash the coarse product after it has been filtered by the pre-filter and the fine filter;

[0012] A homogenizing reactor is used to refine the washed crude product by adding water to obtain a mixture;

[0013] A homogenizer pre-filter, connected to the homogenizer, is used to perform preliminary filtration of the mixture from the homogenizer;

[0014] The homogenizer fine filter, connected to the homogenizer pre-filter, is used to finely filter the liquid phase after it has been filtered by the homogenizer pre-filter to obtain the precursor solution;

[0015] A crude product tank, connected to the fine filter of the homogenizing vessel, is used to store the precursor solution;

[0016] A spray dryer, connected to the product tank, is used to dry the precursor solution to obtain a ternary precursor.

[0017] A second aspect of the present invention provides a method for preparing a ternary precursor using spent lithium-ion batteries, the method comprising:

[0018] (1) A polyamino substance is first mixed with an acid solution to obtain a eutectic solvent; wherein the acid solution is selected from at least one of reducing organic carboxylic acids;

[0019] (2) The eutectic solvent is mixed with the refined black powder from waste lithium-ion batteries for the second time, and the crude product and eutectic solvent are obtained by the first separation.

[0020] (3) The crude product is washed with an alcohol; then the washed crude product is mixed with deionized water for a third time; a precursor solution and a graphite mixture are obtained through a second separation; then the precursor solution is dried to obtain the precursor;

[0021] (4) The precursor is mixed with lithium salt and then calcined to obtain the cathode material.

[0022] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0023] (1) The device for preparing ternary precursors using waste lithium-ion batteries has the advantages of simple structure, low energy consumption and high selectivity for transition metal elements.

[0024] (2) The method of the present invention has the advantages of being green and environmentally friendly and selectively extracting lithium through the leaching step of eutectic solvent, realizing the recycling of solvent and the separation of lithium from heavy metals, which is conducive to the efficient recovery of lithium in the future. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a process for preparing ternary precursors by recovering ternary waste lithium-ion battery black powder using a eutectic solvent, according to one embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures

[0027] 1-Diaphragm pump 2-Acid feed tank 3-First pre-melting kettle

[0028] 4-Reaction vessel 5-Pre-filter 6-Fine filter

[0029] 7-Circulation tank; 8-Second pre-melting kettle; 9-First flushing tank

[0030] 10-Second flushing tank; 11-Homogenizer; 12-Heat exchanger

[0031] 13-Homogenizer pre-filter; 14-Homogenizer fine filter; 15-Crude product tank

[0032] 16-Spray dryer 17-Rinse tank 18-Steam distributor Detailed Implementation

[0033] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0034] The first aspect of this invention provides an apparatus for preparing ternary precursors from spent lithium-ion batteries, as shown in Figure 1, the apparatus comprising:

[0035] At least one pre-melting vessel is used to dissolve a solid solvent to form a liquid solvent;

[0036] Reactor 4, connected to the pre-melting vessel, is used to leach the refined black powder from waste lithium-ion batteries with liquid solvent from the pre-melting vessel to obtain a solid-liquid mixture.

[0037] Pre-filter 5, connected to the reaction vessel 4, is used for preliminary filtration of the solid-liquid mixture;

[0038] Fine filter 6 is connected to the pre-filter 5 and is used to finely filter the liquid phase after the pre-filter 5 has been initially filtered.

[0039] At least one rinsing tank, connected to the pre-filter 5 and the fine filter 6, is used to wash the coarse product after it has been filtered by the pre-filter 5 and the fine filter 6;

[0040] The homogenizing vessel 11 is used to refine the washed crude product with water to obtain a mixture;

[0041] The homogenizer pre-filter 13 is connected to the homogenizer 11 and is used to perform preliminary filtration of the mixture from the homogenizer;

[0042] The homogenizer fine filter 14 is connected to the homogenizer pre-filter 13 and is used to finely filter the liquid phase after it has been filtered by the homogenizer pre-filter 13 to obtain the precursor solution.

[0043] The crude product tank 15 is connected to the homogenizer filter 14 and is used to store the precursor solution;

[0044] The spray dryer 16 is connected to the crude product tank 15 and is used to dry the precursor solution to obtain the ternary precursor.

[0045] According to the present invention, a two-stage filtration is adopted. The purpose of pre-filtration is to intercept a portion of the larger particles to ensure the smoothness of filtration. The purpose of fine filtration is to intercept the smaller particles that have flowed through the pre-filter to ensure complete filtration.

[0046] According to a preferred embodiment of the present invention, the pre-melting vessel includes a first pre-melting vessel 3 and a second pre-melting vessel 8; the first pre-melting vessel 3 is used to provide liquid solvent to the reaction vessel; the second pre-melting vessel 8 is a replenishment vessel used to replenish liquid solvent to the reaction vessel.

[0047] According to a preferred embodiment of the present invention, the rinsing tank includes a rinsing storage tank 17, a first rinsing tank 9, and a second rinsing tank 10;

[0048] The flushing tank 17 is connected in sequence to the pre-filter 5 and the fine filter 6, and is used to store flushing agent and flush the material in the pre-filter 5 and the fine filter 6;

[0049] The first rinsing tank 9 is connected to the fine filter 6 and is used to receive the primary rinsing liquid after rinsing the pre-filter 5 and the fine filter 6 in the rinsing tank 17; the second rinsing tank 10 is connected to the pre-filter 5 and is used to receive the secondary rinsing liquid after rinsing the pre-filter 5 and the fine filter 6 in the first rinsing tank 9.

[0050] According to the present invention, residual organic matter in the material is rinsed by setting up the above-mentioned rinsing tank.

[0051] According to a preferred embodiment of the present invention, the device further includes:

[0052] Acid raw material tank 2 is connected to the reaction vessel 4 and the pre-melting vessels 3 and 8, and is used to supply acid solution to the reaction vessel 4 and the pre-melting vessels 3 and 8;

[0053] Diaphragm pump 1; connected to the acid raw material tank 2, used to add material to the acid raw material tank 2.

[0054] According to a preferred embodiment of the present invention, the device further includes: a circulation tank 7, connected to the fine filter 6 and the reaction vessel 4, which is used to receive the liquid filtered by the fine filter 6 and return it to the reaction vessel 4.

[0055] According to a preferred embodiment of the present invention, the device further includes:

[0056] Heat exchanger 12, connected to the homogenizing vessel 11, is used to reflux the water vapor volatilized from the homogenizing vessel 11;

[0057] Steam distributor 18 is jacketed with the premelting vessel 3, 8, the reaction vessel 4 and the homogenizing vessel 11, and is used to provide heat to the premelting vessel 3, 8, the reaction vessel 4 and the homogenizing vessel 11.

[0058] In some embodiments of the present invention, pressure gauges and thermometers are provided on the pre-melting vessels 3 and 8, the reaction vessel 4 and the homogenizing vessel 11 for measuring the pressure and temperature inside the vessels.

[0059] In some embodiments of the present invention, the tanks with storage properties are equipped with level gauges for measuring the liquid level inside the tank.

[0060] In some embodiments of the present invention, all liquids in the tank (except for acid feedstock pumped by diaphragm pump) are transported by gravitational potential energy plus nitrogen pressure.

[0061] In this invention, the reaction vessel 4 is connected to the acid raw material tank 2, the pre-melting tanks 3 and 8, the pre-filter 5, and the circulation tank 7 respectively. It is an important component to ensure the circulation of the device. Ball valves are installed at the connection points between the reaction vessel 4 and each tank to control the materials entering and leaving the reaction vessel.

[0062] In some embodiments of the present invention, the steam distributor is equipped with a thermometer and a pressure gauge to measure the steam temperature and pressure. Four shut-off valves are installed on the jacketed pipelines connecting the steam distributor to the pre-melting vessel, replenishment vessel, reaction vessel, and homogenizing vessel to control the pressure of each jacket, thereby controlling the temperature of each jacket. Pressure gauges are also installed on the jackets of the pre-melting vessel, replenishment vessel, reaction vessel, and homogenizing vessel to measure the temperature of each jacket.

[0063] In this invention, the filter residue in the four filters—pre-filter 5, fine filter 6, homogenizer pre-filter 13, and homogenizer fine filter 14—is manually removed and manually added to the required vessel.

[0064] The device of this invention uses a eutectic solvent for graded intermittent cyclic processing of ternary lithium-ion battery black powder, which has the advantages of good selectivity for transition metal elements, high leaching efficiency, and simple operation.

[0065] A second aspect of the present invention provides a method for preparing a ternary precursor from spent lithium-ion batteries, using the apparatus described in the first aspect above, the method comprising:

[0066] (1) A polyamino substance is first mixed with an acid solution to obtain a eutectic solvent; wherein the acid solution is selected from at least one of reducing organic carboxylic acids;

[0067] (2) The eutectic solvent is mixed with the refined black powder from waste lithium-ion batteries for the second time, and the crude product and eutectic solvent are obtained by the first separation.

[0068] (3) The crude product is washed with an alcohol; then the washed crude product is mixed with deionized water for a third time; a precursor solution and a graphite mixture are obtained through a second separation; then the precursor solution is dried to obtain the precursor;

[0069] (4) The precursor is mixed with lithium salt and then calcined to obtain the cathode material.

[0070] According to the present invention, the leaching step using a eutectic solvent has the advantages of being green and environmentally friendly and selectively extracting lithium, realizing the recycling of the solvent and the separation of lithium from heavy metals, which is beneficial for the subsequent efficient recovery of lithium.

[0071] According to the present invention, the purpose of recycling waste lithium-ion batteries and regenerating cathode materials is achieved through the steps of leaching, alcohol washing, filtration and lithium supplementation roasting. The steps are simple and easy to operate.

[0072] According to a preferred embodiment of the present invention, the polyamino substance is selected from at least one of ethylenediamine, divinyltriamine, trivinyltetramine, benzidine, 4,4'-diamino-3,3'-dimethylbiphenyl, bianisidine, 2,6-diaminoanthracene, and 4,4'-diaminoterphenyl.

[0073] According to a preferred embodiment of the present invention, the polyamino-containing substance is ethylenediamine and benzidine, and the molar ratio of the two is 1:2-8, for example 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, and any value within the range of any two values, but not limited thereto.

[0074] According to a preferred embodiment of the present invention, in step (1), the molar ratio of the polyamino substance to the acid is (1-5):(1-15), for example 1:2, 1:3, 1:4, 1:5, 1:9, 1:10, 2:5, 2:7, 3:7, 4:15, 5:1, 5:2, 5:3, 5:8, 5:15, and any value within the range of any two values, but not limited thereto.

[0075] According to a preferred embodiment of the present invention, in step (1), the molar concentration of the reducing organic carboxylic acid in the multi-component eutectic solvent is 0.2-15 mol / L, for example 0.2 mol / L, 1 mol / L, 2 mol / L, 3 mol / L, 5 mol / L, 8 mol / L, 10 mol / L, 12 mol / L, 15 mol / L, and any value within any range of any two values, but not limited thereto.

[0076] According to a preferred embodiment of the present invention, the reducing organic carboxylic acid is selected from at least one of aliphatic carboxylic acids, alicyclic carboxylic acids, and aromatic carboxylic acids.

[0077] According to a preferred embodiment of the present invention, the aliphatic carboxylic acid is selected from at least one of formic acid, lactic acid, methanesulfonic acid, acetic acid, oxalic acid, propionic acid, malonic acid, butyric acid, maleic acid, tartaric acid, fumaric acid, adipic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, ricinoleic acid, citric acid, and malic acid; preferably selected from at least one of formic acid, acetic acid, oxalic acid, propionic acid, malonic acid, butyric acid, tartaric acid, citric acid, and malic acid.

[0078] According to a preferred embodiment of the present invention, the alicyclic carboxylic acid is selected from at least one of cyclopropionic acid, cyclobutane acetic acid, cyclopentane acetic acid, cyclohexane acetic acid, cyclopentane carboxylic acid, and 1,3,5-cyclohexanetriic acid; preferably selected from at least one of cyclopropionic acid, cyclobutane acetic acid, cyclopentane acetic acid, cyclohexane acetic acid, and cyclopentane carboxylic acid.

[0079] According to a preferred embodiment of the present invention, the aromatic carboxylic acid is selected from at least one of benzoic acid, p-toluenesulfonic acid, phthalic acid, terephthalic acid, 2,5-dihydroxyterephthalic acid, 2-aminoterephthalic acid, 2,6-naphthalenedicarboxylic acid, and cinnamic acid; preferably selected from at least one of p-toluenesulfonic acid and cinnamic acid.

[0080] According to a preferred embodiment of the present invention, the reducing organic carboxylic acid is selected from at least one of formic acid, lactic acid, methanesulfonic acid, acetic acid, oxalic acid, propionic acid, malonic acid, maleic acid, tartaric acid, fumaric acid, adipic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, ricinoleic acid, citric acid, malic acid, cyclopropionic acid, cyclobutaneacetic acid, cyclopentaneacetic acid, cyclohexaneacetic acid, 1,3,5-cyclohexanetriic acid, benzoic acid, p-toluenesulfonic acid, phthalic acid, terephthalic acid, 2,5-dihydroxyterephthalic acid, 2-aminoterephthalic acid, and 2,6-naphthalenedicarboxylic acid.

[0081] According to a preferred embodiment of the present invention, the reducing organic carboxylic acid is selected from at least one of formic acid, terephthalic acid, 2,5-dihydroxyterephthalic acid, 2-aminoterephthalic acid, 2,6-naphthalenedicarboxylic acid, and 1,3,5-cyclohexanetriic acid.

[0082] According to a preferred embodiment of the present invention, in step (2), the solid-liquid ratio of the refined black powder and the eutectic solvent is 1g:(10-100)L, for example, 1g:10L, 1g:20L, 1g:50L, 1g:80L, 1g:100L, and any value within the range of any two values, but not limited thereto.

[0083] According to a preferred embodiment of the present invention, in step (3), the solid-liquid ratio of the washed crude product to deionized water is 1g:(10-100)L, for example, 1g:10L, 1g:20L, 1g:50L, 1g:80L, 1g:100L, and any value within the range of any two values, but not limited thereto.

[0084] According to a preferred embodiment of the present invention, in step (4), the amount of lithium salt added is 1-1.5 times the amount of lithium element missing, based on the amount of lithium element.

[0085] According to a preferred embodiment of the present invention, in step (1), the temperature of the first mixing is 60-80°C and the time is 20-60 min.

[0086] According to a preferred embodiment of the present invention, in step (2), the temperature of the second mixing is 100-150°C and the time is 2-6 hours.

[0087] According to a preferred embodiment of the present invention, in step (3), the temperature of the third mixing is 60-90°C and the time is 0.5-2h.

[0088] According to a preferred embodiment of the present invention, in step (4), the calcination conditions include: first calcining at 500-800℃ for 3-8 hours; then calcining at 700-1000℃ for 5-15 hours.

[0089] According to a preferred embodiment of the present invention, in step (2), the refined black powder of the waste lithium-ion battery is the undersize material obtained by screening lithium battery black powder using a 100-300 mesh sieve.

[0090] According to the present invention, the undersize material is a mixture of positive and negative electrode powders, and the oversize material is a mixture of copper foil, aluminum foil, diaphragm and plastic.

[0091] According to a preferred embodiment of the present invention, the method for preparing the lithium battery black powder includes: discharging the waste lithium-ion battery, disassembling it in the air, and then crushing the positive and negative electrode sheets.

[0092] The lithium battery black powder in this invention can also be purchased directly from recycled lithium battery black powder.

[0093] According to the present invention, the screening process has the advantages of high efficiency and simplicity, and achieves the effect of completely separating more than 95% of the copper and aluminum foil and plastic membrane in the black powder.

[0094] According to a particularly preferred embodiment of the present invention, an apparatus for preparing ternary precursors from spent lithium-ion batteries, such as... Figure 1As shown, the system includes: an acid feed tank 2; a first pre-melting vessel 3 connected to the acid feed tank 2, allowing acid to enter the first pre-melting vessel 3 and melt manually added solid material into a liquid; a second pre-melting vessel 8 connected to the acid feed tank 2, allowing acid to enter the second pre-melting vessel 8 and melt manually added solid material into a liquid; a reaction vessel 4 connected to the first pre-melting vessel 3 and the second pre-melting vessel 8 for easy feeding; a pre-filter 5 and a fine filter 6, which filter the material in the reaction vessel 4 stage by stage; a circulation tank 7 connected to the fine filter 6 and the reaction vessel 4, used to receive the liquid filtered by the fine filter 6 and recycle it into the reaction vessel 4; a rinsing storage tank 17 connected to the pre-filter 5, in which the rinsing agent rinses the solid material in the filters through the pre-filter 5 and the fine filter 6; and a first rinsing tank 9 connected to the fine filter 6, used to receive the first rinsing agent after rinsing the filter through the pre-filter 5 and the fine filter 6 in the rinsing storage tank 17. Washing liquid; second rinsing tank 10, connected to pre-filter 5, which is used to receive the secondary washing liquid after rinsing the first rinsing tank 9 through pre-filter 5 and fine filter 6; homogenizing vessel 11, which is used to add deionized water to dissolve the solids in pre-filter 5 and fine filter 6; condenser, connected to homogenizing vessel 11, which is used to condense the deionized water evaporated in homogenizing vessel 11 and return it to homogenizing vessel 11; homogenizing vessel pre-filter 13 and homogenizing vessel fine filter 14, connected to homogenizing vessel 11 and crude product tank 15, which are used to filter the solid-liquid mixture in homogenizing vessel 11 in stages; crude product tank 15, which is used to store the liquid material after stage filtration; spray dryer 16, connected to crude product tank 15, which is used to dry the liquid in crude product tank 15 to obtain the precursor product; steam distributor 18, which is connected to the jackets of first premelting vessel 3, second premelting vessel 8, reaction vessel 4 and homogenizing vessel 11 respectively, to provide heat.

[0095] In some embodiments, pressure gauges and thermometers are provided on the first premelting vessel 3, the second premelting vessel 8, the reaction vessel 4, and the homogenizing vessel 11 to measure the pressure and temperature inside the vessel.

[0096] In some embodiments, the storage tank is equipped with a level gauge to measure the liquid level inside the tank.

[0097] In some embodiments, the transport of all liquids in the tank (except for the acid feedstock delivered by diaphragm pump 1) is carried out by gravitational potential energy plus nitrogen pressure.

[0098] In some embodiments, the reactor 4 is connected to the acid feed tank 2, the first pre-melting tank 3, the second pre-melting tank 8, the pre-filter 5, and the circulation tank 7, respectively. It is an important component to ensure the circulation of the device. Ball valves are installed at the connection points between the reactor 4 and each tank to control the materials entering and leaving the reactor.

[0099] In some embodiments, the steam distributor 18 is equipped with a thermometer and a pressure gauge to measure the steam temperature and pressure. Four shut-off valves are installed on the jacketed pipelines connecting the steam distributor to the first premelting vessel 3, the second premelting vessel 8, the reaction vessel 4, and the homogenizing vessel 11, respectively controlling the pressure of each jacket and thus controlling the temperature of each jacket. Pressure gauges are installed on the jackets of the first premelting vessel 3, the second premelting vessel 8, the reaction vessel 4, and the homogenizing vessel 11 to measure the temperature of each jacket.

[0100] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited to the following description.

[0101] Unless otherwise specified in the following preparation examples, embodiments, and comparative examples, all conditions should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0102] In the following examples and comparative examples,

[0103] The battery black powders NCM333, NCM523, NCM622, NCM811, and NCA were purchased from Hebei Zhonghua Lithium Battery Technology Co., Ltd.

[0104] The following parameters were measured by inductively coupled plasma-optical emission spectroscopy (ICP-OES).

[0105] Leaching rate: η = (CV / mLi) × 100%; where η is the lithium leaching rate (%); C is the final Li concentration (mg·L). -1 V is the initial volume of the leaching solution (L); mLi is the mass of Li in the LiCoO2 powder (mg).

[0106] Precursor loss rate: δ=(1-mS / mL)×100%; where δ is the precursor loss rate (%), mS is the actual mass of the precursor obtained (g), and mL is the theoretical mass of the precursor obtained (g).

[0107] Example 1

[0108] A method for preparing ternary precursors by recovering ternary waste lithium-ion battery black powder using a eutectic solvent, employing methods such as... Figure 1 The flowchart shown includes the following steps:

[0109] (1) Purchased battery black powder NCM333 directly and put it into a 150-mesh vibrating screen for sieving to obtain refined black powder under the screen and a copper-aluminum-plastic mixture over the screen. The refined black powder is used for later use and the over the screen is recycled.

[0110] (2) Ethylenediamine and formic acid were mixed in the first pre-melting vessel 3 at a molar ratio of 4:1, and then heated at 80°C for 40 min to prepare a eutectic solvent;

[0111] (3) Take 2.5 kg of the refined black powder obtained in step (1) and 100 L of the eutectic solvent obtained in step (2) (solid-liquid ratio S:L = 25 g / L) and put them into a 200 L reactor 4. Heat and stir to 110 °C and keep at that temperature for 5 h. The reaction is then complete. After the reaction, the solution is separated by a pre-filter 5 and a fine filter 6 to obtain a recycled eutectic solvent and a crude product. The recycled eutectic solvent can be put back into the reactor 4 to react with the refined black powder.

[0112] (4) 80 kg of methanol from the washing tank 17 washes the crude product in the pre-filter 5 and fine filter 6 to remove the residual eutectic solvent in the crude product. The resulting primary washing solution enters the first washing tank 9. The primary washing solution in the first washing tank 9 washes the crude product in the pre-filter 5 and fine filter 6 again to obtain the precursor crude product after secondary washing. The secondary washing solution enters the second washing tank 10 and then returns to the reactor 4 via the circulation tank 7.

[0113] (5) The crude precursor obtained in step (4) and 100 kg of deionized water are placed in the homogenizer 11, stirred and heated to 60°C and kept at the temperature for 0.5 h. Then, the mixture is filtered three times in the homogenizer pre-filter 13 and homogenizer fine filter 14 to separate the precursor solution and graphite carbon black residue. The graphite carbon black residue is recovered, and the precursor solution is spray-dried in the spray dryer 16 to obtain the precursor solid.

[0114] (6) The precursor solid obtained in step (5) and the lithium element in the lithium salt are mixed in a molar ratio of 1:1.05. The mixed material is pre-calcined at 500°C for 8 hours and then calcined at 1000°C for 5 hours to obtain the cathode material.

[0115] The leaching rate and precursor loss rate were measured and are shown in Table 1.

[0116] Example 2

[0117] (1) Purchased battery black powder NCM523 directly and put it into a 200-mesh vibrating screen for sieving to obtain refined black powder under the screen and a copper-aluminum-plastic mixture over the screen. The refined black powder is used for later use and the over the screen is recycled.

[0118] (2) Benzidine and oxalic acid are mixed in the first pre-melting vessel 3 at a molar ratio of 1:2.5, and then heated at 60°C for 60 min to prepare a eutectic solvent;

[0119] (3) Take 2.5 kg of the refined black powder obtained in step (1) and 100 L of the eutectic solvent obtained in step (2) (solid-liquid ratio S:L = 30 g / L) and put them into a 200 L reactor 4. Heat and stir to 115 °C and keep at that temperature for 4 h. The reaction is then complete. After the reaction, the solution is separated by a pre-filter 5 and a fine filter 6 to obtain a recycled eutectic solvent and a crude product. The recycled eutectic solvent can be put back into the reactor 4 to react with the refined black powder.

[0120] (4) 90 kg of ethanol from the rinsing tank 17 is used to rinse the crude product in the pre-filter 5 and fine filter 6 to remove the residual eutectic solvent in the crude product. The resulting primary washing solution enters the first rinsing tank 9. The primary washing solution in the first rinsing tank 9 is used to rinse the crude product in the pre-filter 5 and fine filter 6 again to obtain the precursor crude product after secondary washing. The secondary washing solution enters the second rinsing tank 10 and then returns to the reactor 4 via the circulation tank 7.

[0121] (5) The crude precursor obtained in step (4) and 120 kg of deionized water are placed in the homogenizer 11, stirred and heated to 60°C and kept at the temperature for 0.5 h. Then, the mixture is filtered three times in the homogenizer pre-filter 13 and homogenizer fine filter 14 to separate the precursor solution and graphite carbon black residue. The graphite carbon black residue is recovered, and the precursor solution is spray-dried in the spray dryer 16 to obtain the precursor solid.

[0122] (6) The precursor solid obtained in step (5) and the lithium element in the lithium salt are mixed in a molar ratio of 1:1.1. The mixed material is pre-calcined at 800°C for 3 hours and then calcined at 700°C for 10 hours to obtain the cathode material.

[0123] The leaching rate and precursor loss rate were measured and are shown in Table 1.

[0124] Example 3

[0125] (1) Purchased battery black powder NCM622 directly and put it into a 250 mesh vibrating screen for screening to obtain refined black powder under the screen and a copper-aluminum-plastic mixture over the screen. The refined black powder is used for later use and the over the screen is recycled.

[0126] (2) Trivinyltetramine and terephthalic acid were mixed in a molar ratio of 1:3 in the first pre-melting vessel 3, and then heated at 70°C for 50 min to prepare a eutectic solvent.

[0127] (3) Take 2.5 kg of the refined black powder obtained in step (1) and 150 L of the eutectic solvent obtained in step (2) (solid-liquid ratio S:L = 35 g / L) and put them into a 200 L reactor 4. Heat and stir to 125 °C and keep at that temperature for 4.5 h. The reaction is then complete. After the reaction, the solution is separated by a pre-filter 5 and a fine filter 6 to obtain a recycled eutectic solvent and a crude product. The recycled eutectic solvent can be returned to reactor 4 to react with the refined black powder.

[0128] (4) 100 kg of propanol from the rinsing tank 17 is used to rinse the crude product in the pre-filter 5 and fine filter 6 to remove the residual eutectic solvent in the crude product. The resulting primary washing solution enters the first rinsing tank 9. The primary washing solution in the first rinsing tank 9 is used to rinse the crude product in the pre-filter 5 and fine filter 6 again to obtain the precursor crude product after secondary washing. The secondary washing solution enters the second rinsing tank 10 and then returns to the reactor 4 via the circulation tank 7. (5) The precursor crude product obtained in step (4) and 100 kg of deionized water are placed in the homogenizing reactor 11, stirred and heated to 60°C and kept at a constant temperature for 0.5 h. Then, the mixture is filtered three times in the homogenizing reactor pre-filter 13 and homogenizing reactor fine filter 14 to separate the precursor solution and graphite carbon black slag. The graphite carbon black slag is recovered, and the precursor solution is spray-dried in the spray dryer 16 to obtain the precursor solid.

[0129] (6) The precursor solid obtained in step (5) and the lithium element in the lithium salt are mixed in a molar ratio of 1:1.5. The mixed material is pre-calcined at 700°C for 6 hours and then calcined at 900°C for 8 hours to obtain the cathode material.

[0130] The leaching rate and precursor loss rate were measured and are shown in Table 1.

[0131] Example 4

[0132] The method of Example 1 differs in that, in step (2), instead of mixing ethylenediamine and formic acid in the first pre-melting vessel 3 in a molar ratio of 4:1, benzidine and formic acid are mixed in the first pre-melting vessel 3 in a molar ratio of 4:1.

[0133] The leaching rate and precursor loss rate were measured and are shown in Table 1.

[0134] Example 5

[0135] The method of Example 1 differs in that, in step (2), instead of mixing the mixture of ethylenediamine and benzidine (the molar ratio of ethylenediamine and benzidine is 1:2.5) with formic acid in the first pre-melting kettle 3 in a molar ratio of 4:1, benzidine and formic acid are mixed in the first pre-melting kettle 3 in a molar ratio of 4:1.

[0136] The leaching rate and precursor loss rate were measured and are shown in Table 1.

[0137] Comparative Example 1

[0138] The method of Example 1 is different in that the first rinsing tank 9 is omitted. That is, 100 kg of methanol from the rinsing tank 17 is used to rinse the crude product in the pre-filter 5 and fine filter 6 to wash away the residual eutectic solvent in the crude product, and the crude precursor product after one wash is obtained. The washing liquid after the first wash enters the second rinsing tank 10 and then returns to the reactor 4 through the circulation tank 7.

[0139] The leaching rate and precursor loss rate were measured and are shown in Table 1.

[0140] Comparative Example 2

[0141] The method of Example 1 is the same, except that the fine filter 6 is omitted, that is, the solution after the reaction is separated only by the pre-filter 5 to obtain the recycled eutectic solvent and the crude product.

[0142] The leaching rate and precursor loss rate were measured and are shown in Table 1.

[0143] Comparative Example 3

[0144] The method of Example 1 is different in that, in step (2), ethylenediamine and phenol are mixed in the first pre-melting vessel 3 at a molar ratio of 4:1, and then heated at 80°C for 40 min to prepare a eutectic solvent.

[0145] The leaching rate and precursor loss rate were measured and are shown in Table 1.

[0146] Comparative Example 4

[0147] The method of Example 1 is different in that, in step (2), formamide and formic acid are mixed in the first pre-melting vessel 3 at a molar ratio of 4:1, and then heated at 80°C for 40 min to prepare a eutectic solvent.

[0148] The leaching rate and precursor loss rate were measured and are shown in Table 1.

[0149] Table 1

[0150] serial number solid-liquid ratio Leaching rate (%) Precursor loss rate (%) Example 1 2.5kg:100L 92.3％ 1.83％ Example 2 3.0kg:100L 91.8％ 2.04％ Example 3 3.5kg:100L 92.1％ 1.99％ Example 4 2.5kg:100L 91.1％ 2.11％ Example 5 2.5kg:100L 94.9％ 1.2％ Comparative Example 1 2.5kg:100L 76.1％ 6.68％ Comparative Example 2 2.5kg:100L 62.5％ 10.2％ Comparative Example 3 2.5kg:100L 50.9％ 15.2％ Comparative Example 4 2.5kg:100L 78.6％ 7.63％

[0151] As can be seen from the results in Table 1, Example 1 has a significantly better effect with high leaching rate and low precursor loss rate.

[0152] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A device for preparing ternary precursors from waste lithium-ion batteries, characterized in that, The device comprises: at least one pre-melting kettle for dissolving a solvent to form a liquid solvent; a reaction kettle connected to the pre-melting kettle for leaching reaction of the liquid solvent from the pre-melting kettle on the black powder of the waste lithium ion battery to obtain a solid-liquid mixture; a pre-filter connected to the reaction kettle for preliminary filtration of the solid-liquid mixture; a fine filter connected to the pre-filter for fine filtration of the liquid phase after preliminary filtration by the pre-filter; at least one washing tank connected to the pre-filter and the fine filter for washing the crude product after filtration by the pre-filter and the fine filter; the washing tank comprises a washing storage tank, a first washing tank and a second washing tank; the washing storage tank is connected to the pre-filter and the fine filter in sequence for storing washing agent and washing the materials in the pre-filter and the fine filter; the first washing tank is connected to the fine filter for receiving the first washing liquid after the pre-filter and the fine filter are washed by the washing agent in the washing storage tank; the second washing tank is connected to the pre-filter for receiving the second washing liquid after the pre-filter and the fine filter are washed by the first washing liquid in the first washing tank; a homogenizing kettle for water refining of the washed crude product to obtain a mixture; a homogenizing kettle pre-filter connected to the homogenizing kettle for preliminary filtration of the mixture from the homogenizing kettle; a homogenizing kettle fine filter connected to the homogenizing kettle pre-filter for fine filtration of the liquid phase after filtration by the homogenizing kettle pre-filter to obtain a precursor solution; a crude product tank connected to the homogenizing kettle fine filter for storing the precursor solution; a spray dryer connected to the product tank for drying the precursor solution to obtain a ternary precursor.

2. The apparatus of claim 1, wherein, The pre-melting kettle comprises a first pre-melting kettle and a second pre-melting kettle; the first pre-melting kettle is used to provide the liquid solvent to the reaction kettle; the second pre-melting kettle is a make-up kettle used to supplement the liquid solvent to the reaction kettle.

3. The apparatus of claim 1 or 2, wherein, The device further comprises: an acid raw material tank connected to the reaction kettle and the pre-melting kettle for providing acid liquid to the reaction kettle and the pre-melting kettle; a diaphragm pump connected to the acid raw material tank for feeding the acid raw material tank.

4. The apparatus of claim 1 or 2, wherein, The device further comprises: a circulating tank connected to the fine filter and the reaction kettle for receiving the liquid after filtration by the fine filter and returning to the reaction kettle.

5. The apparatus of claim 1 or 2, wherein, The device further comprises: a heat exchanger connected to the homogenizing kettle for refluxing the water vapor volatilized from the homogenizing kettle; a steam distributor connected to the jackets of the pre-melting kettle, the reaction kettle and the homogenizing kettle for providing heat to the pre-melting kettle, the reaction kettle and the homogenizing kettle.

6. A method for preparing a ternary precursor from waste lithium-ion batteries, characterized in that, The method comprises: (1) mixing a multi-amino-containing substance with an acid liquid to obtain a eutectic solvent; wherein the acid liquid is selected from at least one of the reducing organic carboxylic acids; the multi-amino-containing substance is selected from at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, benzidine, 4,4'-diamino-3,3'-dimethylbenzidine, dianisidine, 2,6-diaminoanthracene and 4,4'-diaminotriphenylamine; (2) the eutectic solvent is secondly mixed with fine black powder of the waste lithium ion battery, and a crude product and the eutectic solvent are obtained through first separation; (3) the crude product is washed with an alcohol substance, and then the washed crude product is thirdly mixed with deionized water; a precursor solution and a graphite mixture are obtained through second separation; and then the precursor solution is dried to obtain a precursor; (4) the precursor is mixed with a lithium salt, and then is calcined to obtain a positive electrode material.

7. The method of claim 6, wherein, The polyamino-containing substance is selected from ethylenediamine and benzidine, and the molar ratio of the two is 1:2-8; And / or, in step (1), the molar ratio of the polyamino-containing substance to the acid solution is (1-5):(1-15); And / or, in step (1), the molar concentration of the reducing organic carboxylic acid in the polyhydric eutectic solvent is 0.2-15 mol / L.

8. The method of claim 6 or 7, wherein, The reducing organic carboxylic acid is selected from at least one of aliphatic carboxylic acids, alicyclic carboxylic acids and aromatic carboxylic acids.

9. The method of claim 8, wherein, The aliphatic carboxylic acid is selected from at least one of formic acid, lactic acid, methanesulfonic acid, acetic acid, oxalic acid, propionic acid, malonic acid, n-butyric acid, maleic acid, tartaric acid, fumaric acid, adipic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, ricinoleic acid, citric acid and malic acid; And / or, the alicyclic carboxylic acid is selected from at least one of cyclopropaneacetic acid, cyclobutaneacetic acid, cyclopentaneacetic acid, cyclohexaneacetic acid, cyclopentanemethanoic acid and 1,3,5-cyclohexanetricarboxylic acid; And / or, the aromatic carboxylic acid is selected from at least one of benzoic acid, p-toluenesulfonic acid, o-phthalic acid, terephthalic acid, 2,5-dihydroxyterephthalic acid, 2-aminoterephthalic acid, 2,6-naphthalene dicarboxylic acid and cinnamic acid.

10. The method of claim 6 or 7, wherein, In step (2), the solid-liquid ratio of the fine black powder to the eutectic solvent is 1g:(10-100)L; And / or, in step (3), the solid-liquid ratio of the washed crude product to deionized water is 1g:(10-100)L; And / or, in step (4), the amount of the lithium salt added is 1-1.5 times of the amount of the lithium element needed.

11. The method of claim 6 or 7, wherein, In step (1), the temperature of the first mixing is 60-80℃, and the time is 20-60 min; And / or, in step (2), the temperature of the second mixing is 100-150℃, and the time is 2-6 h; And / or, in step (3), the temperature of the third mixing is 60-90℃, and the time is 0.5-2 h; And / or, in step (4), the calcination conditions include: first calcination at 500-800℃ for 3-8 h; and then calcination at 700-1000℃ for 5-12 h.

12. The method of claim 6 or 7, wherein, In step (2), the fine black powder of the waste lithium ion battery is undersize material obtained by screening lithium battery black powder with a 100-300 mesh screening machine.

13. The method of claim 12, wherein, The preparation method of the lithium battery black powder comprises: after the waste lithium ion battery is discharged, the battery is disassembled in air, and then the positive and negative electrode sheets are crushed.

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