Method for separating nickel and cobalt in rural waste ternary lithium ion battery
This method separates and recovers nickel and cobalt from lithium-ion batteries using electroplating, solving the problem of difficult separation and recovery of nickel and cobalt in existing technologies. It achieves efficient and simple nickel and cobalt recovery, is applicable to a variety of ternary lithium-ion batteries, has a wide range of applications, and features simple separation steps and a short cycle.
Patent Information
- Application Number
- CN202511464269.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-14
- Publication Date
- 2026-01-13
AI Technical Summary
Existing technologies make it difficult to efficiently and easily separate and recycle nickel and cobalt from lithium-ion batteries, resulting in their long-term presence in the environment and threatening environmental and human health.
The electroplating method utilizes the acidic leachate from waste ternary lithium-ion batteries as the electrolyte. Electroplating is performed by passing electricity through the anode and cathode to separate nickel and cobalt. The nickel-cobalt alloy coating adheres to the cathode surface, while the other metals remain in the solution. Subsequently, manganese oxide or manganese hydroxide can be prepared, and lithium can be prepared into lithium hydroxide or lithium carbonate.
It achieves efficient separation and recovery of nickel and cobalt with minimal loss of nickel and cobalt, has a wide range of applications, simple separation steps, short cycle, and high recovery rate, and is suitable for ternary lithium-ion batteries with different contents.
Abstract
Description
Technical Field
[0001] This invention pertains to the recycling of waste lithium batteries, specifically involving a method for separating nickel and cobalt from waste ternary lithium-ion batteries in rural areas. Background Technology
[0002] Lithium-ion batteries are widely used due to their high specific capacity, long lifespan, high rated voltage, low self-discharge, and lightweight portability. They are currently the most promising high-efficiency rechargeable batteries and the fastest-growing chemical energy storage power source. With the development of lithium-ion battery technology, cathode materials have evolved from lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and binary cathode materials to the third-generation cathode materials—ternary NCM / NCA cathode materials, especially mass-produced cathode materials such as NCM111, NCM523, NCM622, and NCM811. The lifespan of lithium-ion batteries is generally 3-5 years. Over time, more and more waste lithium-ion batteries are generated in rural areas. Heavy metals in lithium-ion batteries pose a significant threat to the environment and human health. Nickel and cobalt ions, in particular, are extremely harmful to both the environment and human health. Nickel and cobalt pollution is non-degradable; regardless of their form, they cannot be permanently removed through chemical reactions or biodegradation. Their toxicity can only be reduced by altering their form, such as their valence state or compound form. If left untreated, it will persist in the environment, posing a constant threat to both the environment and human health.
[0003] Therefore, it is necessary to find a simple process that can reuse nickel and cobalt. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a method for separating nickel, cobalt and other metals from rural waste ternary lithium-ion batteries. This method is simple, enables rapid separation of nickel and cobalt from other metals, and allows for the reuse of nickel and cobalt with a high recovery rate.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a method for separating nickel and cobalt from waste ternary lithium-ion batteries in rural areas, comprising: using acidic leachate from waste ternary lithium-ion batteries as an electrolyte, with nickel in the acidic leachate as the nickel source for nickel electroplating and cobalt as the cobalt source for cobalt electroplating; adding a pH buffer; inserting an anode electrode and a cathode electrode; stirring the electrolyte; and applying current to the anode and cathode for electroplating. After electroplating, the cathode has a nickel-cobalt alloy plating layer. After electroplating, the electrolyte may contain a small amount of nickel, cobalt, and other metals, or it may contain only other metals.
[0006] The acidic leachate from the waste ternary lithium-ion battery described in this invention is obtained by dissolving and filtering the positive electrode sheet or the positive electrode active material peeled off from the waste ternary lithium-ion battery using an acidic solution. The selection of the acidic solution is the same as in existing technologies, preferably hydrochloric acid, with a concentration of 0.3-2 mol / L. The waste ternary lithium-ion battery positive electrode sheet or the positive electrode active material peeled off is obtained using existing technologies. The waste ternary lithium-ion battery is discharged and disassembled, and the positive electrode sheet or the further collected positive electrode active material is collected for acid leaching. Acid leaching is a prior art technique. The preferred leaching time is 1-3 hours, the preferred stirring speed is 200-400 rpm / min, and the preferred temperature is 40-70℃. Within these conditions, the positive electrode or positive electrode active material of the waste ternary lithium-ion battery can be fully leached. The pH of the acidic leachate is adjusted to 2-5.
[0007] In the method described in this invention, an acidic pH buffer is used. Boric acid is preferred as the acidic pH buffer. The pH range of the acidic pH buffer is 3.5-6, and the acidic pH buffer is preferably 5-10 mol / L.
[0008] The stirring method described in this invention is the same as that in the prior art, using ultrasonic stirring, air stirring or mechanical stirring. When using mechanical stirring, the preferred speed is ≤80 rpm / min, and more preferably 20-40 rpm / min.
[0009] In the method described in this invention, the anode and cathode are energized with direct current, the electroplating voltage is preferably ≤15V, more preferably 5-10V, and the electroplating time is preferably 1-7h. Within this time range, the separation of nickel, cobalt and other metals in waste ternary lithium-ion batteries can be achieved.
[0010] The selection of anode and cathode in the method described in this invention is the same as in the prior art, typically using platinum or graphite sheets as anodes and aluminum or graphite sheets as cathodes.
[0011] Compared with the prior art, the present invention is characterized by: 1. This invention has a wide range of applications and is applicable to ternary lithium-ion batteries with different nickel, cobalt, and manganese contents.
[0012] 2. This invention can separate nickel, cobalt and other metals in waste ternary lithium-ion batteries in a single electroplating step, with nickel and cobalt uniformly plated on the cathode surface in the form of an alloy, while manganese and lithium remain in the solution. Subsequently, manganese can be prepared into manganese oxide or manganese hydroxide, and lithium can be prepared into lithium hydroxide or lithium carbonate.
[0013] 3. The separation steps of the method described in this invention are simple, the separation cycle is short, and nickel-cobalt alloy coatings can be directly prepared with minimal loss of nickel and cobalt. Detailed Implementation
[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Specific Implementation Example 1 (1) Discharge and dismantle the waste ternary lithium ions using existing technology, further collect the positive electrode active material of the battery, add 0.5 mol / L hydrochloric acid solution, the reaction temperature is 40℃, the stirring speed is 200 rpm / min, the leaching time is 2h, filter, and adjust the pH of the obtained leaching solution to 2.5.
[0016] (2) Add 5 mol / L of boric acid solution with pH 3.5-6 to the leachate with pH 2.5 to obtain the electrolyte. Use ultrasonic vibration to vibrate the electrolyte.
[0017] (3) The anode is graphite and the cathode is graphite. The cathode and anode are energized with a voltage of 5V and an electroplating time of 4h to obtain a nickel-cobalt alloy coating on the cathode.
[0018] (4) After electroplating, the nickel and cobalt in the solution obtained in step (3) are measured. (C1 is the ion concentration in the leachate, and C2 is the ion concentration in the solution after electroplating) It is calculated that the recovery rate of nickel is 96.4% and the recovery rate of cobalt is 93.5%.
[0019] (5) Collect the cathode nickel-cobalt alloy coating obtained in step (3), dissolve it with hydrochloric acid solution to obtain a solution, and determine the lithium and manganese contents in the solution to be 0.00001ppm and 0.00007ppm, respectively.
[0020] Example 2 (1) Discharge and dismantle the waste ternary lithium ions using existing technology, further collect the positive electrode active material of the battery, add 0.8 mol / L hydrochloric acid solution, the reaction temperature is 45℃, the stirring speed is 200 rpm / min, the leaching time is 2h, filter, and adjust the pH of the obtained leaching solution to 3.
[0021] (2) Add 5.7 mol / L of boric acid solution with pH 3.5-6 to the leachate with pH 3 to obtain the electrolyte. Stir the electrolyte at a stirring speed of 20 rpm / min.
[0022] (3) Platinum is used as the anode and graphite is used as the cathode. The cathode and anode are energized with a voltage of 5.6V and an electroplating time of 5h to obtain a nickel-cobalt alloy coating on the cathode.
[0023] (4) After electroplating, the nickel and cobalt in the solution obtained in step (3) are measured. (C1 is the ion concentration in the leachate, and C2 is the ion concentration in the solution after electroplating) It is calculated that the recovery rate of nickel is 97.8% and the recovery rate of cobalt is 94.6%.
[0024] (5) Collect the cathode nickel-cobalt alloy coating obtained in step (3), dissolve it with hydrochloric acid solution to obtain a solution, and determine the lithium and manganese contents in the solution to be 0.00000ppm and 0.00008ppm, respectively.
[0025] Example 3 (1) Discharge and dismantle the waste ternary lithium ions using existing technology, further collect the positive electrode active material of the battery, add 0.7 mol / L hydrochloric acid solution, the reaction temperature is 55℃, the stirring speed is 250 rpm / min, the leaching time is 2.5 h, filter, and adjust the pH of the obtained leaching solution to 3.
[0026] (2) Add 5.5 mol / L of boric acid solution with pH 3.5-6 to the leachate with pH 3 to obtain the electrolyte. Stir the electrolyte at a stirring speed of 25 rpm / min.
[0027] (3) The anode is graphite and the cathode is graphite. The cathode and anode are energized with a voltage of 6V and an electroplating time of 7h to obtain a nickel-cobalt alloy coating on the cathode.
[0028] (4) After electroplating, the nickel and cobalt in the solution obtained in step (3) are measured. (C1 is the ion concentration in the leachate, and C2 is the ion concentration in the solution after electroplating) It is calculated that the recovery rate of nickel is 94.7% and the recovery rate of cobalt is 91.5%.
[0029] (5) Collect the cathode nickel-cobalt alloy coating obtained in step (3), dissolve it with hydrochloric acid solution to obtain a solution, and determine the lithium and manganese contents in the solution to be 0.00002ppm and 0.00004ppm, respectively.
[0030] Example 4 (1) Discharge and dismantle the waste ternary lithium ions using existing technology, further collect the positive electrode active material of the battery, add 0.35mol / L hydrochloric acid solution, the reaction temperature is 50℃, the stirring speed is 275rpm / min, the leaching time is 2.5h, filter, and adjust the pH of the obtained leaching solution to 3.5.
[0031] (2) Add 7 mol / L of boric acid solution with pH 3.5-6 to the leachate with pH 3.5 to obtain the electrolyte. Use ultrasonic vibration to vibrate the electrolyte.
[0032] (3) The anode is graphite and the cathode is graphite. The cathode and anode are energized with a voltage of 7V and an electroplating time of 6.5h to obtain a cathode nickel-cobalt alloy coating.
[0033] (4) After electroplating, the nickel and cobalt in the solution obtained in step (3) are measured. (C1 is the ion concentration in the leachate, and C2 is the ion concentration in the solution after electroplating) It is calculated that the recovery rate of nickel is 97.2% and the recovery rate of cobalt is 94.5%.
[0034] (5) Collect the cathode nickel-cobalt alloy coating obtained in step (3), dissolve it with hydrochloric acid solution to obtain a solution, and determine the lithium and manganese contents in the solution to be 0.00000ppm and 0.00006ppm, respectively.
[0035] Example 5 (1) Discharge and dismantle the waste ternary lithium ions using existing technology, further collect the positive electrode active material of the battery, add 0.5 mol / L hydrochloric acid solution, the reaction temperature is 40℃, the stirring speed is 200 rpm / min, the leaching time is 4h, filter, and adjust the pH of the obtained leaching solution to 2.5.
[0036] (2) Add 5 mol / L of boric acid solution with pH 3.5-6 to the leachate with pH 2.5 to obtain the electrolyte. Use ultrasonic vibration to vibrate the electrolyte.
[0037] (3) Platinum is used as the anode and aluminum is used as the cathode. The cathode and anode are energized with a voltage of 5V and an electroplating time of 4h to obtain a nickel-cobalt alloy coating on the cathode.
[0038] (4) After electroplating, the nickel and cobalt in the solution obtained in step (3) are measured. (C1 is the ion concentration in the leachate, and C2 is the ion concentration in the solution after electroplating) It is calculated that the recovery rate of nickel is 96.4% and the recovery rate of cobalt is 93.5%.
[0039] (5) Collect the cathode nickel-cobalt alloy coating obtained in step (3), dissolve it with hydrochloric acid solution to obtain a solution, and determine the lithium and manganese contents in the solution to be 0.00001ppm and 0.00007ppm, respectively.
[0040] Example 6 (1) Discharge and dismantle the waste ternary lithium ions using existing technology, further collect the positive electrode active material of the battery, add 1.2 mol / L hydrochloric acid solution, the reaction temperature is 48℃, the stirring speed is 300 rpm / min, the leaching time is 2.7 h, filter, and adjust the pH of the obtained leaching solution to 3.7.
[0041] (2) Add 6.5 mol / L of boric acid solution with pH 3.5-6 to the leachate with pH 3.7 to obtain the electrolyte. Use ultrasonic vibration to vibrate the electrolyte.
[0042] (3) Platinum is used as the anode and graphite is used as the cathode. The cathode and anode are energized with a voltage of 6.5V and an electroplating time of 7h to obtain a nickel-cobalt alloy coating on the cathode.
[0043] (4) After electroplating, the nickel and cobalt in the solution obtained in step (3) are measured. (C1 is the ion concentration in the leachate, and C2 is the ion concentration in the solution after electroplating) It is calculated that the recovery rate of nickel is 98.9% and the recovery rate of cobalt is 98.5%.
[0044] (5) Collect the cathode nickel-cobalt alloy coating obtained in step (3), dissolve it with hydrochloric acid solution to obtain a solution, and determine the lithium and manganese contents in the solution to be 0.00000ppm and 0.00008ppm, respectively.
[0045] Example 7 (1) Discharge and dismantle the waste ternary lithium ions using existing technology, further collect the positive electrode active material of the battery, add 1.2 mol / L hydrochloric acid solution, the reaction temperature is 55℃, the stirring speed is 300 rpm / min, the leaching time is 3h, filter, and adjust the pH of the obtained leaching solution to 2.5.
[0046] (2) Add 8 mol / L of boric acid solution with pH 3.5-6 to the leachate with pH 2.5 to obtain the electrolyte. Use ultrasonic vibration to vibrate the electrolyte.
[0047] (3) Platinum is used as the anode and graphite is used as the cathode. The cathode and anode are energized with a voltage of 5.5V and an electroplating time of 7h to obtain a nickel-cobalt alloy coating on the cathode.
[0048] (4) After electroplating, the nickel and cobalt in the solution obtained in step (3) are measured. (C1 is the ion concentration in the leachate, and C2 is the ion concentration in the solution after electroplating) It is calculated that the recovery rate of nickel is 97.8% and the recovery rate of cobalt is 94.7%.
[0049] (5) Collect the cathode nickel-cobalt alloy coating obtained in step (3), dissolve it with hydrochloric acid solution to obtain a solution, and determine the lithium and manganese contents in the solution to be 0.00002ppm and 0.00012ppm, respectively.
[0050] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that any other specific implementations that can be made without departing from the spirit or essential characteristics of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for separating nickel and cobalt from waste ternary lithium-ion batteries in rural areas, characterized in that: The acidic leachate from waste ternary lithium-ion batteries is used as the electrolyte, with nickel in the acidic leachate serving as the nickel source for nickel electroplating and cobalt serving as the cobalt source for cobalt electroplating. A pH buffer is added, and the anode and cathode electrodes are inserted. The electrolyte is stirred, and electricity is applied to the anode and cathode for electroplating. After electroplating, the cathode electrode has a nickel-cobalt alloy coating.
2. The method according to claim 1, characterized in that... The acidic leachate from the waste ternary lithium-ion batteries is obtained by dissolving and filtering the positive electrode sheet or the positive electrode active material peeled off from the waste ternary lithium-ion batteries using an acidic solution.
3. The method according to claim 1, characterized in that... The pH buffer mentioned is an acidic pH buffer.
4. The method according to claim 3, characterized in that... The pH range of the acidic pH buffer is 3.5-6.
5. The method according to claim 1, characterized in that... The stirring is performed using ultrasonic stirring, air stirring, or mechanical stirring.
6. The method according to claim 1, characterized in that... The pH of the acidic leachate from the waste ternary lithium-ion batteries is adjusted to 2-5.
7. The method according to claim 1, characterized in that... The electroplating voltage is ≤15V.
8. The method according to claim 1, characterized in that... The electroplating voltage is 5-10V.
9. The method according to claim 1, characterized in that... The electroplating time is 1-7 hours.
10. The method according to claim 1, characterized in that... The anode sheet is made of platinum or graphite, and the cathode sheet is made of aluminum or graphite.