Recycling method for pre-extraction of lithium from waste ternary battery material
By using proton solvents under high temperature and high pressure conditions to undergo a proton replacement reaction with the positive electrode material of the waste ternary battery material, the problems of low recovery efficiency and serious pollution in the prior art are solved, and efficient and environmentally friendly lithium element recycling is achieved.
Patent Information
- Application Number
- CN202411511343.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2025-02-07
AI Technical Summary
The prior art has low recycling efficiency of lithium elements in waste lithium-ion batteries, and traditional methods require high temperature roasting or the use of a large number of acidic reagents, resulting in high energy consumption and serious pollution.
Environmentally friendly proton solvents are used as lithium extractors, and proton replacement reactions are carried out with the positive electrode material of the waste ternary battery material under high temperature and high pressure conditions of 120-250°C to achieve efficient pre-lithium extraction of lithium elements.
It reduces energy consumption and waste emissions during the recycling process, improves the recycling efficiency of lithium elements, and eliminates the need for acidic reagents, reducing pollution.
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Figure CN119390142A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for recycling waste ternary battery materials, in particular to a method for recycling waste ternary battery materials by pre-extracting lithium, and belongs to the technical field of waste battery recycling. Background Art
[0002] Lithium-ion batteries are one of the most common energy storage batteries. Due to their excellent performance in cost and performance, they are widely used in electronic consumer products, electric vehicles and other fields. The lithium required for the production of lithium-ion batteries is currently extracted mainly from salt lake brine and high-grade lithium ore, but lithium extracted mainly from these two resources is likely to be difficult to meet the growing market demand. Therefore, extracting lithium from waste lithium-ion batteries not only has higher economic value, but also reduces environmental pollution caused by resource mining.
[0003] The traditional pyrometallurgical smelting converts metal compounds such as nickel, cobalt, and copper in waste lithium-ion batteries into metal melts at a high temperature of more than 1000°C. However, in this process, lithium is not reduced to a single metal, but is lost in the slag in the form of oxides. The traditional wet process usually adopts the mode of "complete leaching-transition metal separation-lithium recovery". Although this method can recover lithium in the last step, the recovery process is cumbersome and consumes a lot of chemical reagents. And a small amount of lithium will be mixed in when the transition metal is separated, resulting in lithium loss. In addition, since the lithium concentration in the solution to be extracted after multiple steps of separation is not high, the recovery rate of lithium will be further reduced. Therefore, combined with the current status of lithium resources, it is urgent to increase the attention paid to the resource recovery of lithium elements in waste batteries.
[0004] Recently, researchers have developed a selective pre-extraction lithium technology. By taking steps or prior extraction of lithium elements, shortening the later separation and purification process, the loss of lithium in the overall process can be minimized, which is of great significance for making up for the scarcity of lithium primary resources, achieving high-purity recovery of all elements, maintaining sustainable development, and improving economic benefits. However, the current pre-extraction lithium process generally requires high-temperature transformation, including carbon thermal reduction, aluminum thermal reduction, hydrogen reduction, nitration roasting, chlorination roasting, sulfidation roasting, oxidation roasting, etc., to convert the lithium element in the positive electrode material into a water-soluble compound, such as lithium oxide, lithium carbonate, lithium hydroxide, etc., and then realize the separation of lithium and other metal elements during the water leaching process. Although this method has large processing capacity, good selectivity, and low reagent cost, it has high energy consumption, and the tail gas generated during the roasting process needs to be absorbed and purified to meet the emission standards. Therefore, researchers proposed to directly use acidic reagents to selectively leach lithium from positive electrode materials, such as sulfuric acid to achieve selective leaching of lithium from lithium iron phosphate positive electrode materials, and oxalic acid to achieve selective leaching of lithium from lithium cobalt oxide positive electrode materials. Although this method has a short process and low energy consumption, it requires the use of a large amount of acidic reagents, and the wastewater thus produced is prone to secondary pollution during the treatment process. Summary of the invention
[0005] In view of the technical problems existing in the prior art, the purpose of the present invention is to provide a method for pre-extracting lithium from waste ternary battery materials. The method directly pre-extracts lithium from waste ternary battery materials by utilizing an environmentally friendly proton-containing solvent as a solvent, which not only avoids the high-temperature roasting stage in the traditional method, but also does not require the use of acidic reagents. It can effectively reduce the energy consumption and the generation of three wastes in the process of recycling waste batteries, and can improve the recovery efficiency of lithium elements.
[0006] In order to achieve the above technical objectives, the present invention provides a method for recycling waste ternary battery materials by pre-extracting lithium. The method is to place waste ternary positive electrode material powder and a proton solvent in a sealed reactor for lithium extraction at a temperature of 120 to 250°C to obtain a lithium-containing solution.
[0007] Generally, pre-extraction of lithium requires high-temperature transformation or leaching with acidic reagents. The key to the technical solution of the present invention is that an environmentally friendly, proton-rich solvent can be directly used as a lithium extracting agent, and the high proton concentration in the solvent is used to strengthen the replacement reaction between protons and lithium ions in the positive electrode material under high temperature and high pressure conditions, thereby achieving efficient pre-extraction of lithium from waste ternary battery materials. At the preferred lithium extraction temperature, the higher the temperature in the sealed reactor, the more it promotes the exchange of protons and lithium ions in the proton solvent, and improves the dissolution efficiency of lithium ions.
[0008] As a preferred solution, the mass ratio of the waste ternary cathode material powder to the protic solvent is 1:5 to 1:50. If the solid-liquid ratio is too low, the amount of solvent used will be too large, and the concentration of the obtained lithium-containing solution will be low, resulting in poor economic benefits. If the solid-liquid ratio is too high, the pressure in the sealed reactor at the same temperature will be low, resulting in the inability to completely extract the lithium in the material, and the lithium extraction efficiency will be low. Further preferably, the mass ratio of the waste ternary cathode material powder to the protic solvent is 1:10 to 1:20.
[0009] As a preferred solution, the protic solvent includes at least one of water, methanol, ethanol, and ethylene glycol. The preferred protic solvent is rich in hydrogen protons, and can achieve the replacement of lithium ions in the ternary cathode material under appropriate high temperature and high pressure conditions.
[0010] As a preferred solution, the waste ternary positive electrode material powder is obtained by calcining the positive electrode sheet obtained from the waste ternary battery to remove the conductive agent and the binder and separate the aluminum foil. The calcination adopts the conventional low-temperature calcination in the prior art, such as calcination at a temperature of 300 to 500°C.
[0011] As a preferred solution, the active ingredient of the waste ternary cathode material powder is LiNi 0.33 Co 0.33 Mn 0.33 O2、LiNi 0.5 Co 0.3 Mn 0.2 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.85 Co 0.10 Al 0.05 At least one of O2.
[0012] As a preferred solution, the lithium extraction time is 2 to 10 hours. If the lithium extraction temperature is too low, the diffusion energy barrier of lithium ions cannot be overcome and lithium ions cannot be leached; if the lithium extraction temperature is too high, the effect of lithium extraction will not be further increased, but the energy consumption of lithium extraction will increase, and the recovery cost will increase. Therefore, the further preferred lithium extraction temperature is 160°C to 220°C, and the most preferred is 200°C to 220°C. As the lithium extraction time increases, the lithium extraction rate will increase, but the increasing trend will become slow, but the energy consumption will increase, which is unfavorable. If the lithium extraction time is too short, the leaching efficiency of the lithium element is low, so the reasonable lithium extraction time should be controlled. The further preferred lithium extraction time is 4 to 8 hours.
[0013] As a preferred solution, the lithium-containing solution is carbonated to obtain lithium carbonate, for example, a sodium carbonate solution is used to convert lithium ions in the lithium-containing solution into lithium carbonate precipitates.
[0014] The invention provides a method for recycling waste ternary battery materials by efficient pre-extraction of lithium, and the specific steps are as follows.
[0015] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 300-500° C. at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0016] 2) The waste ternary battery material obtained in step 1) is dispersed in a proton-rich solvent at a mass ratio of 1:5 to 1:50, and transferred to a constant temperature reactor, the reaction temperature is 120 to 250° C., and the lithium extraction time is 2 to 10 hours.
[0017] 3) performing solid-liquid separation on the reactants in step 2);
[0018] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0019] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0020] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:
[0021] The recycling method for pre-extracting lithium from waste ternary positive electrode materials provided by the present invention adopts an environmentally friendly, easily available and inexpensive proton solvent as a lithium extraction reagent, and achieves efficient pre-extraction of lithium from waste ternary positive electrode materials by inducing a replacement reaction between protons and lithium ions, thereby solving the bottleneck problem that the existing pre-extraction lithium technology requires high-temperature roasting or the use of acidic reagents, and reducing energy consumption, reagent usage and the discharge of three wastes in the recycling process.
[0022] The high-efficiency pre-extraction of lithium from waste ternary battery materials provided by the present invention is simple to operate, has a short cycle, low energy consumption, low cost, high lithium extraction efficiency, and is universal, which solves the problems of high energy consumption, high cost, and serious pollution in the prior art, and can further achieve the goal of energy conservation and emission reduction in the battery recycling industry. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is the flow chart for pre-extraction of lithium from waste ternary positive electrode materials.
[0024] Figure 2This is the XRD of the waste ternary positive electrode material before and after lithium extraction; as can be seen from the figure, after the lithium extraction treatment, the diffraction peak corresponding to the ternary material (LiNCMO2) completely disappeared, and the diffraction peak corresponding to the hydroxy oxide (HNCMO2) appeared, indicating that the lithium ions in the waste ternary material are completely replaced by protons. DETAILED DESCRIPTION
[0025] The technical scheme of the present invention is further described below in conjunction with specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making innovative efforts are within the scope of protection of the present invention.
[0026] The following examples take ternary battery materials as an example: LiNi 0.33 Co 0.33 Mn 0.33 O2 is used as an example to illustrate.
[0027] Embodiment 1:
[0028] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0029] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:5, and transferred to a constant temperature reactor. The reaction temperature is 220° C. and the lithium extraction time is 4 hours.
[0030] 3) performing solid-liquid separation on the reactants in step 2);
[0031] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0032] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0033] Embodiment 2:
[0034] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0035] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor. The reaction temperature is 220° C. and the lithium extraction time is 4 hours.
[0036] 3) performing solid-liquid separation on the reactants in step 2);
[0037] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0038] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0039] Embodiment 3:
[0040] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0041] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:20, and transferred to a constant temperature reactor, the reaction temperature is 220° C., and the lithium extraction time is 4 hours.
[0042] 3) performing solid-liquid separation on the reactants in step 2);
[0043] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0044] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0045] Embodiment 4:
[0046] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0047] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:50, and transferred to a constant temperature reactor. The reaction temperature is 220° C. and the lithium extraction time is 4 hours.
[0048] 3) performing solid-liquid separation on the reactants in step 2);
[0049] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0050] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0051] Embodiment 5:
[0052] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0053] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor, the reaction temperature is 220° C., and the lithium extraction time is 2 h.
[0054] 3) performing solid-liquid separation on the reactants in step 2);
[0055] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0056] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0057] Embodiment 6:
[0058] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0059] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor. The reaction temperature is 220° C. and the lithium extraction time is 4 hours.
[0060] 3) performing solid-liquid separation on the reactants in step 2);
[0061] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0062] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0063] Embodiment 7:
[0064] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0065] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor, the reaction temperature is 220° C., and the lithium extraction time is 8 hours.
[0066] 3) performing solid-liquid separation on the reactants in step 2);
[0067] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0068] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0069] Embodiment 8:
[0070] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0071] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor, the reaction temperature is 220° C., and the lithium extraction time is 10 hours.
[0072] 3) performing solid-liquid separation on the reactants in step 2);
[0073] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0074] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0075] Example 9: (as a control)
[0076] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0077] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor, the reaction temperature is 80°C (closed system), and the lithium extraction time is 10h.
[0078] 3) performing solid-liquid separation on the reactants in step 2);
[0079] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0080] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0081] Embodiment 10:
[0082] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0083] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor, the reaction temperature is 120° C., and the lithium extraction time is 10 h.
[0084] 3) performing solid-liquid separation on the reactants in step 2);
[0085] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0086] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0087] Embodiment 11:
[0088] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0089] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor, the reaction temperature is 160° C., and the lithium extraction time is 10 h.
[0090] 3) performing solid-liquid separation on the reactants in step 2);
[0091] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0092] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0093] Embodiment 12:
[0094] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0095] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor, the reaction temperature is 250° C., and the lithium extraction time is 10 hours.
[0096] 3) performing solid-liquid separation on the reactants in step 2);
[0097] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0098] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0099] Example 13: (as a control)
[0100] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0101] 2) The waste ternary battery material obtained in step 1) is dispersed in water at a mass ratio of 1:10, and transferred to a constant temperature reactor. The reaction temperature is 80° C. (open system reaction) and the lithium extraction time is 10 h.
[0102] 3) performing solid-liquid separation on the reactants in step 2);
[0103] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0104] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0105] Example 14: (as a control)
[0106] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0107] 2) The waste ternary battery material obtained in step 1) is dispersed in acetone at a mass ratio of 1:10, and transferred to a constant temperature reactor, the reaction temperature is 220° C., and the lithium extraction time is 10 h.
[0108] 3) performing solid-liquid separation on the reactants in step 2);
[0109] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0110] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0111] Embodiment 15:
[0112] 1) Dismantle the waste ternary battery, separate the positive electrode sheet, perform low-temperature calcination at 400°C at low temperature, remove the conductive agent and the binder, separate the aluminum foil, and obtain the waste ternary battery material.
[0113] 2) The waste ternary battery material obtained in step 1) is dispersed in ethanol at a mass ratio of 1:10, and transferred to a constant temperature reactor, the reaction temperature is 220° C., and the lithium extraction time is 10 hours.
[0114] 3) performing solid-liquid separation on the reactants in step 2);
[0115] 4) The solid obtained after separation in step 3) is placed in a vacuum oven and dried at 120° C. for 12 h to obtain a ternary battery material after lithium extraction.
[0116] 5) adding sodium carbonate solution to the liquid obtained after separation in step 3) to obtain lithium carbonate solid, and calculating the extraction rate of lithium element based on the obtained lithium carbonate solid.
[0117] Table 1 Reaction conditions and lithium leaching rate
[0118]
[0119]
[0120] The results in Table 1 show that when the solid-liquid ratio is 1:10, the lithium leaching rate is optimal, which is 95%. Continuing to increase the amount of liquid will not increase the leaching rate of lithium elements, but will increase the use of water and increase the recovery cost; a shorter reaction time is difficult to completely extract the lithium in the material. When the time is 4h, the lithium leaching rate can reach the optimal level, and further increasing the reaction time will not further increase the lithium leaching rate; at a lower temperature, it is difficult to achieve efficient extraction of lithium elements, and at a reaction temperature of 220°C, the lithium leaching rate can reach the optimal level, and further increasing the reaction temperature does not increase the lithium leaching rate; only by using protic solvents can lithium ions in waste ternary materials be effectively extracted, and non-protic solvents cannot extract lithium ions in ternary materials; under low temperature conditions (<100°C), closed systems and open systems do not affect the extraction efficiency of lithium ions.
Claims
1. A method for recovering waste ternary battery materials by pre-extracting lithium, characterized in that: The waste ternary cathode material powder and the proton solvent are placed in a sealed reactor for lithium extraction at a temperature of 120 to 250° C. to obtain a lithium-containing solution.
2. The method for recovering waste ternary battery materials by pre-extracting lithium according to claim 1, characterized in that: The mass ratio of the waste ternary cathode material powder to the proton solvent is 1:5 to 1:
50.
3. A method for recovering waste ternary battery materials by pre-extracting lithium according to claim 2, characterized in that: The protic solvent includes at least one of water, methanol, ethanol and ethylene glycol.
4. A method for recovering waste ternary battery materials by pre-extracting lithium according to any one of claims 1 to 3, characterized in that: The waste ternary positive electrode material powder is obtained by calcining the positive electrode sheet obtained by disassembling the waste ternary battery to remove the conductive agent and the binder and separate the aluminum foil.
5. A method for recovering waste ternary battery materials by pre-extracting lithium according to claim 4, characterized in that: The active component of the waste ternary positive electrode material powder is LiNi 0.33 Co 0.33 Mn 0.33 O2、LiNi 0.5 Co 0.3 Mn 0.2 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.85 Co 0.10 Al 0.05 At least one of O2.
6. A method for recovering waste ternary battery materials by pre-extracting lithium according to any one of claims 1 to 3, characterized in that: The lithium extraction treatment time is 2 to 10 hours.
7. A method for recovering waste ternary battery materials by pre-extracting lithium according to any one of claims 1 to 3, characterized in that: The lithium-containing solution is carbonated to obtain lithium carbonate.