阅读说明：本技术 一种废旧三元锂电池的回收方法 (Recovery method of waste ternary lithium battery ) 是由 张作泰 王树宾 于 2020-06-15 设计创作，主要内容包括：本发明涉及电池回收利用技术领域,尤其涉及一种废旧三元锂电池的回收方法。该回收方法包括以下步骤：电池前处理,至少对所述废旧三元锂电池的正极片进行粉碎过筛；浸出,将粉碎过筛后的所述正极片浸于碱性溶液中形成反应体系,所述碱性溶液至少包括氨水和还原剂溶液,控制所述反应体系的pH和温度进行浸出反应,得到固体和含有价金属的溶液,所述含有价金属的溶液中有价金属包括锂、钴、镍。本申请的回收方法操作简单、可实现工业应用。本申请仅需要对废旧三元锂电池进行简单的初步粉碎,即可进行后续浸出操作,实现有价金属的回收、解决有价金属难以分离的问题。(The invention relates to the technical field of battery recycling, in particular to a method for recycling waste ternary lithium batteries. The recovery method comprises the following steps: battery pretreatment, namely, at least crushing and sieving the positive plate of the waste ternary lithium battery; and leaching, namely soaking the crushed and sieved positive plate in an alkaline solution to form a reaction system, wherein the alkaline solution at least comprises ammonia water and a reducing agent solution, controlling the pH and the temperature of the reaction system to carry out leaching reaction to obtain a solid and a solution containing valuable metals, and the valuable metals in the solution containing the valuable metals comprise lithium, cobalt and nickel. The recovery method is simple to operate and can realize industrial application. According to the method, only simple preliminary crushing is carried out on the waste ternary lithium battery, the subsequent leaching operation can be carried out, the valuable metal is recycled, and the problem that the valuable metal is difficult to separate is solved.)

1. The method for recycling the waste ternary lithium battery is characterized by comprising the following steps

Battery pretreatment: at least crushing and sieving the positive plate of the waste ternary lithium battery;

leaching: soaking the crushed and sieved positive plate in an alkaline solution to form a reaction system, wherein the alkaline solution comprises ammonia water and a reducing agent solution, controlling the pH and the temperature of the reaction system to carry out leaching reaction to obtain a solid and a solution containing valuable metals, and the valuable metals in the solution containing the valuable metals comprise lithium, cobalt and nickel; wherein the reaction time of the leaching reaction is 30-60 minutes, and the total ammonia concentration of the alkaline solution is 3-4.9 mol/L.

2. The recycling method according to claim 1, wherein the battery pretreatment step is: and crushing and sieving the positive plate of the waste ternary lithium battery to obtain powder of 80-120 meshes.

3. The recovery method according to claim 1, wherein in the leaching step, the pH is controlled to 9.5 to 10.9, the reaction temperature is controlled to 120 to 150 ℃, and the solid-to-liquid ratio in the alkaline leaching reaction is 10 to 50 g/L.

4. The recovery method according to claim 1, wherein in the leaching step, the alkaline solution further comprises an ammonium salt solution, the molar ratio of the ammonia water, the ammonium salt solution and the reducing agent solution is 4-6: 0.5-1.5: 0.5-1, the total ammonia concentration is the sum of the ammonia concentrations in the mixed solution of the ammonia water and the ammonium salt solution, and the total ammonia concentration is 3-4 mol/L; the mass ratio of the reducing agent in the reducing agent solution to the cobalt contained in the positive plate is 2:1-5: 1.

5. The recycling method according to claim 1, wherein the waste ternary lithium battery is selected from a nickel cobalt lithium manganate battery or a nickel cobalt lithium aluminate battery, in the leaching step, the ammonium salt in the ammonium salt solution is selected from one or more of ammonium carbonate, ammonium bicarbonate and ammonium oxalate, and the reducing agent in the reducing agent solution is selected from one or more of sodium sulfite, ammonium sulfite, hydrogen peroxide, sodium thiosulfate and sodium persulfate.

6. The recycling method according to claim 5, wherein the waste ternary lithium battery is a nickel cobalt lithium manganate battery, in the leaching step, the ammonium salt solution is an ammonium sulfate solution, the reducing agent solution is a sodium sulfite solution, the molar ratio of the ammonia water to the ammonium sulfate solution to the sodium sulfite solution is 6:0.5:0.5, the reaction temperature is 150 ℃, the reaction time is 30 minutes, the solid-to-liquid ratio of the leaching reaction is 10-50g/L, and valuable metals in the solution containing valuable metals include lithium, cobalt, nickel and manganese.

7. The recovery method according to any one of claims 1 to 6, further comprising, after the step of leaching, a separation, a precipitation: separating the solid and the solution containing the valuable metals, sieving the separated solid to obtain metal aluminum, introducing carbon dioxide gas into the separated solution containing the valuable metals, and simultaneously distilling ammonia from the solution containing the valuable metals to obtain a precipitate, wherein the precipitate is a carbonate precipitate of the valuable metals.

8. The recycling method according to claim 7, wherein the waste ternary lithium battery is a nickel cobalt lithium manganate battery, in the step of separating and precipitating, excess carbon dioxide is introduced into the solution containing valuable metals, the reaction temperature is 70-90 ℃, the reaction time is 5-8 hours, water is supplemented into the solution containing valuable metals in the process of ammonia distillation, the volume of the solution containing valuable metals before ammonia distillation is V1, the volume of the solution containing valuable metals after water supplementation in the process of ammonia distillation is V2, and V2 is not less than 0.5 x V1, so that precipitates of manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate are obtained.

9. The recycling method according to claim 8, further comprising, after the separating and precipitating steps, roasting: and roasting the lithium carbonate, the nickel carbonate, the cobalt carbonate and the manganese carbonate according to a molar ratio, wherein the roasting temperature is 800-900 ℃, and the roasting time is 3-5 hours, so as to obtain the active material.

10. The recovery method according to claim 9, wherein in the roasting step, the ratio of nickel in the nickel carbonate in terms of mole ratios is: cobalt in the cobalt carbonate: the manganese ratio of the manganese carbonate is 8:1:1, 5:2:3, 6:2:2 or 1:1: 1.

Technical Field

The invention relates to the technical field of battery recycling, in particular to a method for recycling waste ternary lithium batteries.

Background

Along with the popularization and use of various intelligent electronic products and new energy automobiles, the usage amount of the lithium ion battery is larger and larger, and the scrapping amount of the lithium ion battery is larger and larger. Because the lithium ion battery contains a large amount of heavy metals, the lithium ion battery cannot be treated by adopting a traditional landfill mode; and the lithium ion battery contains high-value metal materials such as lithium, cobalt, nickel, aluminum and the like, so that the lithium ion battery is a pity if not recycled. Therefore, the research on the recycling process of the waste lithium ion battery has important economic significance and environmental protection significance.

Disclosure of Invention

The invention aims to provide a method for recovering waste ternary lithium batteries, which aims to solve the problems that the existing method for recovering valuable metals from waste batteries has the defects of complex process, high recovery cost, large amount of waste gas or waste liquid and the like, and further the recovery process is difficult to realize industrialization.

The invention provides a method for recycling waste ternary lithium batteries, which comprises the following steps:

battery pretreatment: at least crushing and sieving the positive plate of the waste ternary lithium battery;

leaching: soaking the crushed and sieved positive plate in an alkaline solution to form a reaction system, wherein the alkaline solution comprises ammonia water and a reducing agent solution, controlling the pH and the temperature of the reaction system to carry out leaching reaction to obtain a solid and a solution containing valuable metals, and the valuable metals in the solution containing the valuable metals comprise lithium, cobalt and nickel; wherein the reaction time of the leaching reaction is 30-60 minutes, and the total ammonia concentration of the alkaline solution is 3-4.9 mol/L.

The valuable metal in the invention is a metal with recovery value in waste batteries.

Further, in the recovery method, the battery pretreatment step includes: and crushing and sieving the positive plate of the waste ternary lithium battery to obtain powder of 80-120 meshes.

Further, in the leaching step, the pH is controlled to be 9.5-10.9, the reaction temperature is controlled to be 120-150 ℃, and the solid-to-liquid ratio in the alkaline leaching reaction is 10-50 g/L.

Further, in the leaching step, the alkaline solution further comprises an ammonium salt solution, the molar ratio of the ammonia water to the ammonium salt solution to the reducing agent solution is 4-6: 0.5-1.5: 0.5-1, the total ammonia concentration is the sum of the ammonia concentrations in the mixed solution of the ammonia water and the ammonium salt solution, and the total ammonia concentration is 3-4 mol/L; the mass ratio of the reducing agent in the reducing agent solution to the cobalt contained in the positive plate is 2:1-5: 1.

Further, the waste ternary lithium battery is selected from a nickel cobalt lithium manganate battery or a nickel cobalt lithium aluminate battery, in the leaching step, the ammonium salt in the ammonium salt solution is selected from one or a mixture of ammonium carbonate, ammonium bicarbonate and ammonium oxalate, and the reducing agent in the reducing agent solution is selected from one or a mixture of sodium sulfite, ammonium sulfite, hydrogen peroxide, sodium thiosulfate and sodium persulfate.

Preferably, the waste ternary lithium battery is a nickel cobalt lithium manganate battery, in the leaching step, the ammonium salt solution is an ammonium sulfate solution, the reducing agent solution is a sodium sulfite solution, the molar ratio of the ammonia water to the ammonium sulfate solution to the sodium sulfite solution is 6:0.5:0.5, the reaction temperature is 150 ℃, the reaction time is 30 minutes, the solid-to-liquid ratio of the leaching reaction is 10-50g/L, and valuable metals in the solution containing valuable metals include lithium, cobalt, nickel and manganese.

Further, the recovery method further comprises, after the step of leaching, separation, precipitation: separating the solid and the solution containing the valuable metals, sieving the separated solid to obtain metal aluminum, introducing carbon dioxide gas into the separated solution containing the valuable metals, and simultaneously distilling ammonia from the solution containing the valuable metals to obtain a precipitate, wherein the precipitate is a carbonate precipitate of the valuable metals.

Further, the waste ternary lithium battery is a nickel cobalt lithium manganate battery, in the step of separating and precipitating, excess carbon dioxide is introduced into the solution containing the valuable metals, the reaction temperature is 70-90 ℃, the reaction time is 5-8 hours, water is supplemented to the solution containing the valuable metals in the process of ammonia distillation, the volume of the solution containing the valuable metals before ammonia distillation is V1, the volume of the solution containing the valuable metals after water supplementation in the process of ammonia distillation is V2, and V2 is not less than 0.5 x V1, so that precipitates of manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate are obtained.

Further, the recovery method further comprises roasting after the separating and precipitating steps: and roasting the lithium carbonate, the nickel carbonate, the cobalt carbonate and the manganese carbonate according to a molar ratio, wherein the roasting temperature is 800-900 ℃, and the roasting time is 3-5 hours, so as to obtain the active material.

The active material in the present invention refers to a material having an electroactive substance in a battery electrode.

Further, in the roasting step, the ratio of nickel in the nickel carbonate: cobalt in the cobalt carbonate: the manganese ratio of the manganese carbonate is 8:1:1, 5:2:3, 6:2:2 or 1:1: 1.

Compared with the prior art, the technical scheme of the application has the following beneficial effects:

firstly, the recovery method of the waste ternary lithium battery is simple to operate, high in leaching efficiency and capable of achieving industrial application. On the first hand, different from the prior art, when the waste ternary lithium battery is recycled, complex pretreatment needs to be carried out on the waste ternary lithium battery (for example, an electrode of the waste ternary lithium battery is soaked in an acid solution or an alkali solution, or the electrode of the waste ternary lithium battery needs to be ground into powder with small particles, or high-temperature roasting under severe conditions needs to be carried out after the electrode needs to be ground), the subsequent leaching operation can be carried out only by simply primarily grinding and sieving the waste ternary lithium battery, and the leaching effect is better when the waste ternary lithium battery is ground into powder with the particle size of 80-120 mm. In the second aspect, the electrode which is only subjected to simple pretreatment is subjected to reduction leaching by adopting an alkaline solution at least comprising ammonia water, an ammonium salt solution and a reducing agent, valuable metals (such as lithium, cobalt, nickel, manganese and the like) in the waste ternary lithium battery can be effectively extracted to be separated from an aluminum current collector by only controlling the total ammonia concentration of the alkaline solution, mainly controlling the sum of the ammonia concentrations of a mixed solution of the ammonia water and the ammonium salt solution to be 3-4.9mol/L, and the method has the advantages of short operation time (the whole leaching process only needs about one hour at most, so that a good leaching effect is achieved), high leaching efficiency, good separation effect and the like, can realize the recovery of the valuable metals, and solves the problem that the valuable metals are difficult to separate; in particular, metallic aluminum can be better precipitated at a pH of 9.5 to 10.9, so that the valuable metal is in solution.

Secondly, the application also carries out important research on the condition parameters of the leaching step in the recovery method. In the leaching step, different leaching liquid types and concentrations thereof, reducing agent types and concentrations thereof, and different reaction conditions (including leaching temperature, time, solid-to-liquid ratio and the like) all have important influence on the leaching efficiency of various metals, so that the leaching efficiency of various metals under different leaching conditions is obtained through a large number of experimental tests and explorations.

Finally, on the basis of leaching the metals by adopting an ammonia solvent, the leached metals are deposited by using carbon dioxide and ammonia distillation, and the deposited metal compound is roasted again to obtain the active material for manufacturing the battery electrode. On one hand, the green recycling purpose of the waste ternary lithium battery can be realized, and on the other hand, the carbon dioxide emission of battery production enterprises can be reduced. Specifically, the ammonia evaporation process can realize the cyclic utilization of ammonia solvent and reduce the consumption of chemical reagents such as acid and alkali, namely, the ammonia evaporated from the ammonia evaporation can be collected by weak acid solution to form ammonium salt solution and then recycled to the leaching step, and the ammonia solvent can be recycled, so the consumption of the chemical reagents can be reduced, and the recovery cost is reduced. The carbon dioxide can be reduced in the process of introducing carbon dioxide for precipitation, so that the method is beneficial to energy conservation and emission reduction and is environment-friendly.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below, and it should be apparent that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terms "comprises" and "comprising," and any variations thereof, of the embodiments of the present application are intended to cover non-exclusive inclusions.