Method for recycling waste lithium ion battery and regenerating positive electrode material
Through the high-temperature calcination and co-precipitation reaction, the problems of environmental pollution and high cost in lithium battery recycling are solved, and the low-cost and environmentally friendly regeneration of the positive electrode material of lithium-ion batteries is achieved, which simplifies the process flow and ensures efficient utilization of resources.
Patent Information
- Application Number
- CN202411300438.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2024-12-27
AI Technical Summary
The existing lithium battery recycling technology has problems such as environmental pollution, high energy consumption, high cost and inconsistent product purity. Especially in industrial production, the use of organic and inorganic acids in the hydrometallurgical process leads to pollution and increase costs.
Using high-temperature calcination and co-precipitation reaction, the positive electrode material powder of ammonium sulfate and waste lithium-ion battery are mixed, and organic acids and inorganic acids are avoided. Deionized water and ammonium bicarbonate are used for leaching and precipitation, so as to achieve regeneration of the positive electrode material. .
It realizes low-cost, environmentally friendly and efficient recycling of waste lithium-ion batteries, simplifies the process flow, maximizes resource utilization, avoids the difficulty of element separation, and ensures product purity and closed-loop recycling.
Smart Images
Figure CN119208790A_ABST
Abstract
Description
Technical field:
[0001] The invention relates to the technical field of lithium battery recycling, and in particular to a method for recycling waste lithium ion batteries and regenerating positive electrode materials. Background technology:
[0002] Waste lithium-ion batteries contain a large amount of toxic and harmful substances. If they are not properly disposed of, they may cause serious pollution to the environment and further affect human health and ecological balance. In addition, waste lithium batteries contain a large amount of valuable metal resources. Recycling these metals can reduce the mining of primary resources and extend the life of resources. They have great environmental and economic value and are very necessary for the recycling and reuse of waste lithium-ion batteries.
[0003] The pyrometallurgical process will produce a large amount of carbon dioxide to pollute the environment and consume a lot of energy, and the recovered alloys still need to be further processed to increase the recycling cost. In addition, many materials in waste lithium-ion batteries only provide energy and are not recycled. The recovery of some metals still needs to be combined with hydrometallurgical processes for further recovery. The direct regeneration process is a non-destructive recycling technology, which refers to a method for directly collecting and recycling waste lithium-ion battery positive electrode materials without destroying their original structure. The challenges faced by this method are the impact of impurities on the regeneration process and the inability to determine whether the purity of the recovered products is consistent. At present, direct recovery is only carried out on a laboratory scale, and there are still many problems in industrial large-scale production. Although wet recovery using inorganic acids and organic acids can leach most valuable metals, it requires the assistance of reducing agents. Often, the cost will rise due to the long process, and the continuous use of chemical reagents will cause environmental pollution and other problems.
[0004] Based on this, in order to overcome the defects of the prior art, the present invention develops a method for recycling waste lithium-ion batteries and regenerating positive electrode materials from the perspectives of environmental friendliness, simple process and low cost. Summary of the invention:
[0005] In view of the above situation, in order to overcome the defects of the prior art, the present invention proposes a method for recycling waste lithium-ion batteries and regenerating positive electrode materials. The method is simple in process, low in cost and avoids the use of organic acid and inorganic acid, thus realizing closed-loop recycling of waste lithium-ion batteries.
[0006] To achieve the above object, the present invention provides the following technical solutions:
[0007] Step (1) discharges, disassembles, calcines and sieves the waste ternary lithium-ion batteries to obtain positive electrode material powder.
[0008] Step (2) The positive electrode material powder and ammonium sulfate are mixed in a certain mass ratio and calcined at high temperature in a muffle furnace.
[0009] Step (3) leaching the calcined product in deionized water and filtering to obtain a leachate rich in valuable metals.
[0010] Step (4) adjusting the molar content of the metal element in the leachate, adding a certain volume of deionized water and ammonium bicarbonate as a reaction base liquid (buffer) into the reactor, slowly dropping the salt solution, ammonia solution and alkaline solution into the reactor through a peristaltic pump for co-precipitation reaction, aging, filtering and drying to obtain a precursor.
[0011] Step (5) The precursor and the lithium source are mixed evenly in a mixer, and then calcined to complete the regeneration of the positive electrode material.
[0012] As a preferred embodiment, the calcination temperature in step (1) is 500-600°C and the calcination time is 3-5h.
[0013] As a preferred embodiment, in step (2), the mass ratio of ammonium sulfate to positive electrode material powder is 3-6 g:g, the calcination temperature is 300-450° C., and the calcination time is 1-2.5 h.
[0014] As a preferred embodiment, in step (3), the water immersion temperature is 50-80°C and the water immersion time is 60-90 minutes.
[0015] As a preferred embodiment, the reaction temperature in step (4) is 55°C.
[0016] As a preferred embodiment, in step (4), the stirring speed of the reactor is controlled to be 600 rpm.
[0017] As a preferred embodiment, in the salt solution adjusted in step (4), Ni:Co:Mn=6:2:2, the total concentration of the salt solution is 2 mol / L, the concentration of ammonia water is 0.2-0.5 mol / L, and the concentration of the alkaline solution is 2 mol / L.
[0018] As a preferred embodiment, in step (4), the pH of the solution is adjusted to 7.6-8.0 and the aging time is 8-24 hours.
[0019] As a preferred embodiment, the molar ratio of the precursor to the lithium source in step (5) is 1:(1.02-1.05).
[0020] As a preferred embodiment, in step (5), the temperature is increased to 450-500°C at 5°C / min, kept at this temperature for 3-5h, and then increased to 800-850°C at 5°C / min, and kept at this temperature for 8-12h.
[0021] This technical solution can effectively recycle waste ternary lithium-ion batteries. Ammonium sulfate has low cost and high activity, and can be used as both a reducing agent and an acidifying agent. Compared with traditional wet recovery, it avoids the use of organic acids and inorganic acids. This method uses the recovered leaching solution rich in valuable metal elements as a raw material to synthesize new positive electrode materials, avoids the difficulty of element separation, and realizes the closed-loop recovery of waste ternary lithium-ion batteries. The recovery method has the advantages of simple process flow, easy operation, low cost and maximum resource utilization. Description of the drawings:
[0022] Figure 1 LiNi prepared in Example 1 0.6 Co 0.2 Mn 0.2 SEM photo of O2 cathode material;
[0023] Figure 2 LiNi prepared in Example 1 0.6 Co 0.2 Mn 0.2 Cycle stability test chart of a lithium half-cell composed of O2 positive electrode material after 100 cycles at a current density of 0.5C in the voltage range of 2.8-4.3V.
[0024] Figure 3 LiNi prepared in Example 2 0.6 Co 0.2 Mn 0.2 SEM photo of O2 cathode material; Specific implementation method:
[0025] The present invention provides a method for recycling waste lithium-ion batteries and regenerating positive electrode materials. The present invention is further described in detail below in conjunction with specific embodiments.
[0026] In the following examples, the waste lithium-ion battery is a nickel-cobalt-manganese (NCM) ternary battery, and the regenerated positive electrode material is LiNi 0.6 Co 0.2 Mn 0.2 O2.
[0027] Example 1
[0028] (1) The waste lithium-ion batteries were immersed in a sodium chloride solution for discharge treatment, the positive electrode sheets were disassembled, and the positive electrode sheets were cut into small squares of 1 cm × 1 cm. -1 The residue was then washed with 5% NaOH solution and deionized water to remove the residual alkali on the surface of the residue, and then dried in a drying oven at 80°C for 24 hours, calcined in a muffle furnace at 500°C for 3 hours, and ground and sieved to obtain the waste positive electrode material.
[0029] (2) 1 g of waste positive electrode material was mixed with 4 g of ammonium sulfate and calcined in a muffle furnace at a calcination temperature of 350°C for 1 h. The calcined product was leached in water at a solid-liquid ratio of 15 g / L at a water immersion temperature of 60°C for 70 min, and a leachate rich in valuable metals was obtained by filtration.
[0030] (3) Adjust the molar ratio of elements in the leachate to Ni:Co:Mn=6:2:2, the total concentration of the salt solution to 2 mol / L, prepare 0.3 mol / L ammonia solution and 2 mol / L Na2CO3. Set the temperature of the reactor to 55°C, add a certain volume of deionized water and ammonium bicarbonate as the reaction base liquid (buffer) to the reactor, slowly add the salt solution, ammonia solution and alkaline solution to the reactor through a peristaltic pump for co-precipitation reaction, control the pH of the solution in the reactor to be stable at 7.9, age for 8 hours after the reaction, and obtain the precursor after filtering and drying.
[0031] (4) The precursor obtained in step (3) and lithium carbonate are mixed and ground evenly in a mixer, and then calcined in a muffle furnace, heated to 450°C at a heating rate of 5°C / min, kept at this temperature for 3 hours, and then heated to 800°C at a heating rate of 5°C / min, kept at this temperature for 8 hours, and cooled naturally to obtain a positive electrode material. The molar ratio of the precursor to the lithium carbonate is 1:1.03.
[0032] Example 2
[0033] (1) The waste lithium-ion batteries were immersed in a sodium chloride solution for discharge treatment, the positive electrode sheets were disassembled, and the positive electrode sheets were cut into small squares of 1 cm × 1 cm. -1 The residue was then washed with 5% NaOH solution and deionized water to remove the residual alkali on the surface of the residue, and then dried in a drying oven at 80°C for 24 hours, calcined in a muffle furnace at 550°C for 4 hours, and ground and sieved to obtain the waste positive electrode material.
[0034] (2) 1 g of waste positive electrode material was mixed with 3 g of ammonium sulfate and calcined in a muffle furnace at a calcination temperature of 300°C for 2 h. The calcined product was leached in water at a solid-liquid ratio of 15 g / L at a water immersion temperature of 80°C for 90 min, and a leachate rich in valuable metals was obtained by filtration.
[0035] (3) Adjust the molar ratio of elements in the leachate to Ni:Co:Mn=6:2:2, the total concentration of the salt solution to 2 mol / L, prepare 0.5 mol / L ammonia solution and 2 mol / L Na2CO3. Set the temperature of the reactor to 55°C, add a certain volume of deionized water and ammonium bicarbonate as the reaction base liquid (buffer) to the reactor, slowly add the salt solution, ammonia solution and alkaline solution to the reactor through a peristaltic pump for co-precipitation reaction, control the pH of the solution in the reactor to be stable at 7.7, age for 16 hours after the reaction, and obtain the precursor after filtering and drying.
[0036] (4) The precursor obtained in step (3) and lithium carbonate are mixed and ground evenly in a mixer, and then calcined in a muffle furnace, heated to 480°C at a heating rate of 5°C / min, kept warm for 4 hours, continued to heat to 820°C at a heating rate of 5°C / min, kept warm for 10 hours, and cooled naturally to obtain a positive electrode material. The molar ratio of the precursor to lithium carbonate is 1:1.02.
[0037] Example 3
[0038] (1) The waste lithium-ion batteries were immersed in a sodium chloride solution for discharge treatment, the positive electrode sheets were disassembled, and the positive electrode sheets were cut into small squares of 1 cm × 1 cm. -1 The residue was then washed with 5% NaOH solution and deionized water to remove the residual alkali on the surface of the residue, and then dried in a drying oven at 80°C for 24 hours, calcined in a muffle furnace at 580°C for 3.5 hours, and ground and sieved to obtain the waste positive electrode material.
[0039] (2) 1 g of waste positive electrode material was mixed with 6 g of ammonium sulfate and calcined in a muffle furnace at a calcination temperature of 450°C for 2.5 h. The calcined product was leached in water at a solid-liquid ratio of 15 g / L at a leaching temperature of 50°C for 80 min, and a leachate rich in valuable metals was obtained by filtration.
[0040] (3) Adjust the molar ratio of elements in the leachate to Ni:Co:Mn=6:2:2, the total concentration of the salt solution to 2 mol / L, prepare 0.4 mol / L ammonia solution and 2 mol / L Na2CO3. Set the temperature of the reactor to 55°C, add a certain volume of deionized water and ammonium bicarbonate as the reaction base liquid (buffer) to the reactor, slowly add the salt solution, ammonia solution and alkaline solution to the reactor through a peristaltic pump for co-precipitation reaction, control the pH of the solution in the reactor to be stable at 8.0, age for 12 hours after the reaction, and obtain the precursor after filtering and drying.
[0041] (4) The precursor obtained in step (3) and lithium carbonate are mixed and ground evenly in a mixer, and then calcined in a muffle furnace, heated to 450°C at a heating rate of 5°C / min, kept warm for 1 hour, continued to heat to 880°C at 5°C / min, kept warm for 12 hours, and cooled naturally to obtain a positive electrode material. The molar ratio of the precursor to lithium carbonate is 1:1.035.
[0042] Example 4
[0043] (1) The waste lithium-ion batteries were immersed in a sodium chloride solution for discharge treatment, the positive electrode sheets were disassembled, and the positive electrode sheets were cut into small squares of 1 cm × 1 cm. -1 The residue was then washed with 5% NaOH solution and deionized water to remove the residual alkali on the surface of the residue, and then dried in a drying oven at 80°C for 24 hours, calcined in a muffle furnace at 600°C for 3 hours, and ground and sieved to obtain the waste positive electrode material.
[0044] (2) 1 g of waste positive electrode material was mixed with 5 g of ammonium sulfate and calcined in a muffle furnace at a calcination temperature of 400°C for 1.5 h. The calcined product was leached in water at a solid-liquid ratio of 15 g / L at a water immersion temperature of 70°C for 60 min, and a leachate rich in valuable metals was obtained by filtration.
[0045] (3) Adjust the molar ratio of elements in the leachate to Ni:Co:Mn=6:2:2, the total concentration of the salt solution to 2 mol / L, prepare 0.2 mol / L ammonia solution and 2 mol / L Na2CO3. Set the temperature of the reactor to 55°C, add a certain volume of deionized water and ammonium bicarbonate as the reaction base liquid (buffer) to the reactor, slowly add the salt solution, ammonia solution and alkaline solution to the reactor through a peristaltic pump for co-precipitation reaction, control the pH of the solution in the reactor to be stable at 7.8, age for 24 hours after the reaction, and obtain the precursor after filtering and drying.
[0046] (4) The precursor obtained in step (3) and lithium carbonate are mixed and ground evenly in a mixer, and then calcined in a muffle furnace, heated to 500°C at a heating rate of 5°C / min, kept warm for 3 hours, continued to heat to 800°C at 5°C / min, kept warm for 9 hours, and cooled naturally to obtain a positive electrode material. The molar ratio of the precursor to lithium carbonate is 1:1.04.
Claims
1. A method for recycling waste lithium-ion batteries and regenerating positive electrode materials, characterized in that: The steps include: Step (1) discharges, disassembles, calcines and sieves the waste ternary lithium-ion batteries to obtain waste positive electrode material powder. Step (2) mixing the waste positive electrode material powder and ammonium sulfate in a certain mass ratio and calcining them at high temperature in a muffle furnace. Step (3) leaching the calcined product in deionized water and filtering to obtain a leachate rich in valuable metals. Step (4) adjusting the molar content of the metal element in the leachate, adding a certain volume of deionized water and ammonium bicarbonate as a reaction base liquid (buffer) into the reactor, slowly dropping the salt solution, ammonia solution and alkaline solution into the reactor through a peristaltic pump for co-precipitation reaction, aging, filtering and drying to obtain a precursor. Step (5) The precursor and the lithium source are mixed evenly in a mixer, and then calcined to complete the regeneration of the positive electrode material.
2. A method for recycling waste lithium-ion batteries and regenerating positive electrode materials as claimed in claim 1, characterized in that: In step (1), the calcination temperature is 500-600° C. and the calcination time is 3-5 hours.
3. A method for recycling waste lithium-ion batteries and regenerating positive electrode materials as claimed in claim 1, characterized in that: In step (2), the mass ratio of ammonium sulfate to positive electrode material powder is 3-6, the calcination temperature is 300-450° C., and the calcination time is 1-2.5 h.
4. A method for recycling waste lithium-ion batteries and regenerating positive electrode materials as claimed in claim 1, characterized in that: In step (3), the water immersion temperature is 50-80° C. and the water immersion time is 60-90 min.
5. A method for recycling waste lithium-ion batteries and regenerating positive electrode materials as claimed in claim 1, characterized in that: In step (4), the reaction temperature is 55° C., the stirring speed of the reactor is controlled to be 600 rpm, the Ni:Co:Mn in the salt solution is adjusted to 6:2:2, and the total concentration of the salt solution is 2 mol / L, the concentration of ammonia water is 0.2-0.5 mol / L, the concentration of the alkaline solution is 2 mol / L, the pH of the solution is adjusted to 7.6-8.0, and the aging time is 8-24 h.
6. A method for recycling waste lithium-ion batteries and regenerating positive electrode materials as claimed in claim 1, characterized in that: In step (5), the molar ratio of the precursor to the lithium source is 1:(1.02-1.05), and the calcination method is to increase the temperature to 450-500°C at 5°C / min, keep it warm for 3-5h, and then increase the temperature to 800-850°C at 5°C / min, and keep it warm for 8-12h.