CN116053632A - Recycling method of waste lithium ion battery - Google Patents

Abstract

The invention discloses a method for recovering and treating waste lithium ion batteries, which specifically comprises the following steps: discharging the waste lithium ion batteries; crushing and magnetic separation to separate and remove iron to obtain positive and negative black powder; Roasting under environmental conditions to obtain pretreated black powder; add pretreated black powder to inorganic acid for acid leaching treatment to obtain leaching solution containing lithium, cobalt, nickel and residue containing manganese and graphite. The former is used for separation and recovery of metal elements or directly used It is used in the preparation of positive electrode materials for batteries, which are used in the preparation of catalytic materials or adsorption materials. The invention selectively extracts lithium, cobalt, and nickel elements from positive and negative electrode materials of waste lithium-ion batteries through low-oxygen roasting combined with acid leaching, retains manganese and graphite as precursors of high-performance adsorption catalytic materials, and solves the problem of negative electrodes in common recycling processes Low recovery rate of graphite, long reaction cycle, heavy pollution, high energy consumption and other problems.

Description

A kind of recovery processing method of waste lithium ion battery

technical field

The invention relates to a method for recycling and treating waste lithium ion batteries. The invention belongs to the technical field of solid waste resource recovery.

Background technique

With the rapid development of new energy vehicles, the lithium-ion battery market is growing rapidly. At present, China has become the world's largest producer, consumer and exporter of lithium-ion batteries. However, the lifespan of lithium-ion batteries is generally only 3 to 5 years. With the continuous growth of the lithium battery market, the number of waste lithium-ion batteries is also increasing rapidly. The composition of waste lithium-ion batteries is complex, and improper disposal can cause environmental pollution; and the content of metal elements such as manganese, lithium, cobalt, nickel, and non-metals such as graphite is much higher than that of natural mineral resources, and the development of recycling and reuse technologies for waste lithium-ion batteries It is helpful to prevent and control the pollution of waste batteries and alleviate the shortage of raw materials related to lithium batteries.

The current waste lithium-ion battery treatment method starts from the extraction of valuable elements. First, the positive electrode material is dissolved, and metal elements such as lithium, manganese, cobalt, and nickel enter the solution in the form of Li ⁺ , Mn ⁿ⁺ , Co ⁿ⁺ , and Ni ⁿ⁺ , and then pass Chemical precipitation, electrodeposition, etc. separate and recover lithium, manganese, cobalt, nickel and other elements. In the recycling method of waste lithium-ion batteries, the focus is on the positive electrode material, while there are fewer methods for the recycling and reuse of negative electrode graphite.

In recent years, research has been conducted on waste lithium manganese oxide batteries by acid leaching the mixture of lithium manganate and graphite to obtain graphite with higher purity, and then preparing manganese dioxide from the acid leaching solution, but this method has a long reaction cycle and high energy consumption. , pollutant discharge and other issues.

Contents of the invention

The purpose of the present invention is to overcome above-mentioned deficiencies in the prior art, provide a kind of recovery treatment method of waste lithium-ion battery, have realized efficient leaching from waste lithium-ion battery and selectively recover high-valent metal and prepare high-performance adsorption catalytic material, solve The problems of low recovery rate of negative electrode graphite, long reaction cycle, heavy pollution and high energy consumption of ordinary recovery process are solved.

To achieve the above object, the present invention adopts the following technical solutions:

A kind of recovery processing method of waste lithium ion battery, concrete steps are as follows:

(1) Discharge of waste lithium-ion batteries;

(2) pulverize and remove iron by magnetic separation to obtain positive and negative black powder;

(3) Roasting the positive and negative electrode black powders in a hypoxic environment to obtain pretreated black powders;

(4) Add the pretreatment black powder in the inorganic acid and carry out acid leaching treatment, obtain the leaching liquid containing lithium, cobalt, nickel and the residue containing manganese, graphite, the former carries out metal element separation and recovery or is directly used in the preparation of battery cathode material, and the latter Those used in the preparation of catalytic materials or adsorption materials.

Preferably, in step (1), the used lithium-ion battery is a cylindrical battery, more preferably a ternary lithium-ion battery, and the specific models include but are not limited to 14500, 14650, 17490, 18500, 18650, 26500.

Preferably, the specific method of step (1) is: completely immerse the waste lithium-ion battery in an aqueous solution of sodium chloride or sodium sulfate with a mass concentration of 5-20%, soak for more than 48 hours, and then dry.

Preferably, the specific method of step (2) is: use a hammer crusher (with a dust collection device, no pollution to the outside world) to pulverize the battery after step (1), remove iron by magnetic separation, and use a mill The powder machine strips the black powder from the battery current collector, and uses the cyclone collecting hopper to separate the separator and the black powder to obtain the positive and negative black powder.

Preferably, in step (3), the low-oxygen environment condition is an oxygen volume concentration of 0.5-1%, more preferably a mixed gas of oxygen and nitrogen; the calcination temperature is 600° C., and the calcination time is 60-300 minutes.

Preferably, in step (4), the inorganic acid is 0.5-3 mol/L sulfuric acid solution, the solid-to-liquid ratio of acid leaching is 100 g/L, the acid leaching temperature is 35-95°C, and the acid leaching time is 180-300 minutes.

Preferably, in step (4), metal elements are separated by any method of organic solvent extraction, chemical precipitation or electrodeposition.

Preferably, in step (4), the leaching solution containing lithium, cobalt and nickel is re-precipitated by solid synthesis to obtain the positive electrode material of the battery.

Preferably, in step (4), the residue containing manganese and graphite, its treatment method is selected from any of the following:

(A) Separation of manganese oxide and graphite by flotation, and regeneration of manganese oxide as a catalytic material;

(B) The residue containing manganese and graphite is directly reused as an adsorbent material.

Beneficial effects of the present invention:

Aiming at the shortcomings of existing waste lithium-ion batteries in efficiently recovering positive electrode valuable metals and negative electrode graphite, the present invention proposes a recycling method for waste lithium-ion batteries, which specifically includes the following steps: discharging the waste lithium-ion batteries; crushing and magnetic separation Separating and removing iron to obtain positive and negative electrode black powder; roasting the positive and negative electrode black powder in a low-oxygen environment to obtain pretreated black powder; adding the pretreated black powder to inorganic acid for acid leaching treatment to obtain lithium, cobalt, The leaching solution of nickel and the residue containing manganese and graphite, the former is used for separation and recovery of metal elements or directly used to prepare battery positive electrode materials, and the latter is used to prepare catalytic materials or adsorption materials. The invention selectively extracts lithium, cobalt, and nickel elements from positive and negative electrode materials of waste lithium-ion batteries through low-oxygen roasting combined with acid leaching, retains manganese and graphite as precursors of high-performance adsorption catalytic materials, and solves the problem of negative electrodes in common recycling processes Low recovery rate of graphite, long reaction cycle, heavy pollution, high energy consumption and other issues.

The battery needs to be mechanically crushed and then magnetically separated to separate iron; the battery needs to be crushed and ground for a second time to separate the copper and aluminum foil current collector from the positive and negative black powder to ensure the purity of the waste battery black powder.

After the inorganic acid selectively leaches lithium, cobalt, and nickel, the resulting residue is a mixture of manganese and graphite particles, which can be used to prepare high-performance adsorption catalytic materials and realize the cross-field effective reuse of low-value manganese elements in lithium-ion cathode materials. The process is simple easy to operate.

The invention separates the manganese in the positive electrode material from other valuable metals through the low-oxygen roasting method, and realizes the reuse of manganese and negative electrode graphite, which not only simplifies the entire recovery process, shortens the operation time, reduces the difficulty of operation, and optimizes multiple The recovery process of positive and negative materials of different types of lithium-ion batteries recovers positive manganese and negative graphite, and increases the leaching rate of lithium, nickel, and cobalt to achieve the purpose of recycling positive and negative materials of various types of lithium-ion batteries.

Description of drawings

Fig. 1 is the technological process schematic diagram of the implementation process of the present invention;

Figure 2 is the effect of acid leaching of valuable metals in lithium-ion cathode materials pretreated under the content of 0.5-1% O ₂ , where A is 0.5% O ₂ +N ₂ , B is 0.8% O ₂ +N ₂ , and C is 0.9 % _O2 + _N2 , D is 1% _O2 + _N2 ;

Fig. 3 is the reactivity result of testing acetone oxidation by the anode manganese that reclaims as catalytic material in the present invention; Test condition: total air intake 300mL/min, 500ppm acetone, volumetric concentration 5% oxygen, carrier is nitrogen, space velocity GHSV= 360,000ml/(g·h);

Fig. 4 is the test result of NO catalytic conversion by reclaimed anode manganese as catalytic material in the present invention; Reaction condition: [NO]=[NH ₃ ]=500ppm, [O ₂ ]=5vol%, Ar is balance gas, GHSV=36000h ^-1 ;

Fig. 5 is the NO adsorption curve tested by the recovered positive electrode manganese and negative electrode graphite as adsorption materials in the present invention. The test conditions are: adsorption temperature 30°C, space velocity 24000h ^-1 , inlet NO concentration 500ppm, O concentration ₁₀ %, carrier gas N ₂ ;

Fig. 6 is the NO desorption curve tested by the recovered positive electrode manganese and negative electrode graphite as adsorption materials in the present invention, test conditions: heating rate 10°C/min;

Fig. 7 shows the effect of acid leaching of valuable metals on lithium ion cathode materials treated in Comparative Example 1 and Comparative Example 2, where a is 0.1% O ₂ +99.9% N ₂ , and b is 21% O ₂ +79% N ₂ .

Detailed ways

The present invention will be further described below in conjunction with the examples. It should be noted that the following descriptions are only for explaining the present invention and not limiting its content.

For the convenience of comparison, the 18650 type of used lithium-ion battery is used uniformly for the test below.

Example 1:

0.5% _O2 +99.5% _N2 roasting pretreatment, manganese-containing graphite used as high-performance adsorption material

A kind of recovery processing method of waste lithium-ion battery as shown in Figure 1, concrete steps are as follows:

S1: Lithium-ion battery discharge, put the waste lithium-ion battery into 10wt.% NaCl aqueous solution, soak for more than 48 hours to ensure complete discharge;

S2: The lithium-ion battery is broken, and the fully-discharged lithium-ion battery is mechanically broken to separate the positive electrode, negative electrode and other parts;

S3: Magnetic separation of lithium-ion batteries, the dismantled and broken batteries are subjected to magnetic separation to separate the iron in them;

S4: Secondary crushing of lithium-ion batteries, mechanically crushing the metal-containing battery materials used for subsequent processing after dismantling, and efficiently stripping the black powder from the current collector;

S5: Separation, separate the copper and aluminum foil metal, diaphragm and black powder in the crushed battery material pole piece, so that the black powder can reach a purity of 99.8%;

S6: low-oxygen roasting, the obtained black powder is placed in a roaster containing 0.5% oxygen by volume and the remainder is nitrogen, and roasted for 300 minutes, and cooled to room temperature after the reaction;

S7: acid leaching, the powder after roasting is put into 2mol/L sulfuric acid, after reacting for 180 minutes under the condition of 80 ℃, obtain lithium, nickel, cobalt leaching solution (leaching rate of lithium cobalt nickel is close to 100%, manganese leaching rate is about 20%) ), and the leaching residue containing manganese and graphite; the acid leaching effect is shown in A in Fig. 2;

S8: Regenerate the positive electrode material. According to the positive element ratio of NCM111 ternary lithium-ion battery, adjust the element content of lithium, nickel, and cobalt leaching solution, and add 20% ammonia water to adjust the pH to 8. Stir at 80°C until transparent and viscous Gel, dried in an oven at 120°C for 12 hours, and finally baked in a muffle furnace at 800°C to become the positive electrode material;

S9: The manganese-containing graphite residue is used as a high-performance adsorption material, and the manganese-containing graphite in the leaching residue is directly used as an adsorption material for nitric oxide adsorption.

The obtained manganese-containing graphite was used as an adsorbent material to test the NO adsorption curve and NO desorption curve, as shown in Fig. 5 and Fig. 6 . It can be seen that the NO concentration at the outlet rises rapidly after the adsorption starts, begins to rise slowly after 5 minutes, and reaches the inlet concentration in about 80 minutes; at a heating rate of 10°C/min, the maximum desorption capacity of nearly 80ppm is reached at 300°C .

Example 2:

0.8% O ₂ +99.2% N ₂ roasting pretreatment, manganese-containing graphite to prepare high-performance catalytic materials

A kind of recovery processing method of waste lithium-ion battery as shown in Figure 1, concrete steps are as follows:

S1: Lithium-ion battery discharge, put the waste lithium-ion battery into 15wt.% Na ₂ SO ₄ aqueous solution, soak for more than 48 hours to ensure complete discharge;

S2: The lithium-ion battery is broken, and the fully-discharged lithium-ion battery is mechanically broken to separate the positive electrode, negative electrode and other parts;

S3: Magnetic separation of lithium-ion batteries, the dismantled and broken batteries are subjected to magnetic separation to separate the iron in them;

S4: Secondary crushing of lithium-ion batteries, mechanically crushing the metal-containing battery materials used for subsequent processing after dismantling, and efficiently stripping the black powder from the current collector;

S5: Separation, separate the copper and aluminum foil metal, diaphragm and black powder in the crushed battery material pole piece, so that the black powder can reach a purity of 99.8%;

S6: low-oxygen roasting, the obtained black powder is placed in a roaster with a volume concentration of 0.8% oxygen and the remainder is nitrogen for roasting for 250 minutes, and is cooled to room temperature after the reaction is completed;

S7: acid leaching, the powder after roasting is put into 1.5mol/L sulfuric acid, after reacting 200 minutes under the condition of 85 ℃, obtain lithium, nickel, cobalt leaching liquid (leaching rate of lithium cobalt nickel is all higher than 95%, manganese leaching rate less than 10%), and the leaching residue containing manganese and graphite; the acid leaching effect is shown in B in Figure 2;

S8: Extraction and stripping, adding bis(2,4,4-trimethylpentyl)phosphonic acid (Cyanex272) organic extractant to the aqueous solution containing lithium, cobalt, and nickel to extract cobalt to obtain an organic solvent containing cobalt and an aqueous solution containing lithium and nickel; in the aqueous solution containing lithium and nickel, add neodecanoic acid (2-ethyl-2,5-dimethylhexanoic acid, Versatic 10) organic extractant to extract nickel to obtain nickel-containing Organic solvent and lithium-containing aqueous solution, add sulfuric acid back extraction in organic solvent, obtain cobalt sulfate, nickel sulfate;

S9: chemical precipitation, adding 5.32 X grams (X is the content of lithium in the solution, grams) of sodium carbonate in the lithium-containing aqueous solution, evaporative crystallization, and obtain lithium carbonate precipitation;

S10: Prepare a high-performance catalytic material. The leaching residue contains positive manganese oxide and negative graphite, which are separated by flotation. The manganese oxide is used as a high-performance catalytic material to catalyze the oxidation of acetone.

The obtained manganese oxide was used as a catalytic material to test the reactivity of acetone oxidation, as shown in Figure 3. The activity started to increase rapidly with the temperature from about 225°C, and the reactivity was close to 100% at about 300°C.

Example 3:

0.9% _O2 +99.1% _N2 roasting pretreatment, manganese-containing graphite used as high-performance adsorption material

A kind of recovery processing method of waste lithium-ion battery as shown in Figure 1, concrete steps are as follows:

S1: Lithium-ion battery discharge, put the waste lithium-ion battery into 20wt.% Na ₂ SO ₄ aqueous solution, soak for more than 48 hours to ensure complete discharge;

S2: The lithium-ion battery is broken, and the fully-discharged lithium-ion battery is mechanically broken to separate the positive electrode, negative electrode and other parts;

S3: Magnetic separation of lithium-ion batteries, the dismantled and broken batteries are subjected to magnetic separation to separate the iron in them;

S4: Secondary crushing of lithium-ion batteries, mechanically crushing the metal-containing battery materials used for subsequent processing after dismantling, and efficiently stripping the black powder from the current collector;

S5: Separation, separate the copper and aluminum foil metal, diaphragm and black powder in the crushed battery material pole piece, so that the black powder can reach a purity of 99.8%;

S6: Low-oxygen roasting, placing the obtained black powder in a roasting furnace containing 0.9% oxygen by volume and nitrogen for 280 minutes, and cooling to room temperature after the reaction;

S7: acid leaching, put the roasted powder into 1.8mol/L sulfuric acid, and react for 200 minutes at 80°C to obtain lithium, nickel, cobalt leaching solution (the leaching rate of lithium nickel reaches nearly 100%, and the leaching rate of cobalt 78%, no leaching of manganese), and the leaching residue containing manganese and graphite; the acid leaching effect is shown in Figure 2 C;

S8: Electrodeposition, conduct electrodeposition on the leaching solution containing lithium, nickel, and cobalt, and adjust the deposition voltage to >-1.2V to obtain a cobalt-nickel alloy and a lithium-containing solution;

S9: the precipitation of lithium, add the sodium carbonate of 5.32.X gram (X is the content of lithium in the solution, gram) in lithium-containing aqueous solution, evaporate and crystallize, obtain lithium carbonate precipitation;

S10: The manganese-containing graphite residue is used as a high-performance adsorption material, and the manganese-containing graphite in the leaching residue is directly used as an adsorption material for nitric oxide adsorption.

Example 4:

1% O ₂ +99% N ₂ roasting pretreatment, manganese-containing graphite to prepare high-performance catalytic materials

A kind of recovery processing method of waste lithium-ion battery as shown in Figure 1, concrete steps are as follows:

S1: Lithium-ion battery discharge, put the waste lithium-ion battery into 5wt.% NaCl aqueous solution, soak for more than 48 hours to ensure complete discharge;

S2: The lithium-ion battery is broken, and the fully-discharged lithium-ion battery is mechanically broken to separate the positive electrode, negative electrode and other parts;

S3: Magnetic separation of lithium-ion batteries, the dismantled and broken batteries are subjected to magnetic separation to separate the iron in them;

S4: Lithium-ion battery crushing, mechanically crushing the metal-containing battery materials used for subsequent processing after dismantling, and efficiently stripping the black powder from the current collector;

S5: Separation, separate the copper and aluminum foil metal, diaphragm and black powder in the crushed battery material pole piece, so that the black powder can reach a purity of 99.8%;

S6: low-oxygen roasting, the obtained black powder is placed in a roaster with a volume concentration of 1% oxygen and the remainder is nitrogen for roasting for 200 minutes, and is cooled to room temperature after the reaction is completed;

S7: acid leaching, the powder after roasting is put into 2mol/L sulfuric acid, after reacting for 180 minutes under the condition of 60 ℃, obtain lithium, nickel, cobalt leaching solution (lithium nickel leaching rate is 100%, cobalt leaching rate is 76%, manganese No leaching), and a solid residue containing manganese and graphite; the acid leaching effect is shown in D in Figure 2;

S8: Extraction and stripping, adding bis(2,4,4-trimethylpentyl)phosphonic acid (Cyanex272) organic extractant to the aqueous solution containing lithium, cobalt, and nickel to extract cobalt to obtain an organic solvent containing cobalt and an aqueous solution containing lithium and nickel; in the aqueous solution containing lithium and nickel, add neodecanoic acid (2-ethyl-2,5-dimethylhexanoic acid, Versatic 10) organic extractant to extract nickel to obtain nickel-containing Organic solvent and lithium-containing aqueous solution, add sulfuric acid back extraction in organic solvent, obtain cobalt sulfate, nickel sulfate;

S9: chemical precipitation, adding 5.32 X grams (X is the content of lithium in the solution, grams) of sodium carbonate in the lithium-containing aqueous solution, evaporative crystallization, and obtain lithium carbonate precipitation;

S10: Prepare a high-performance catalytic material. The leaching residue contains positive manganese oxide and negative graphite, which are separated by flotation. The manganese oxide is used as a high-performance catalytic material to catalyze the oxidation of nitrogen monoxide.

The obtained manganese oxide was used as a catalytic material to test the catalytic conversion of NO, and the results are shown in Fig. 4 . The NO conversion rate of the catalytic material reaches the highest at about 275° C., achieving a NO conversion rate greater than 50%.

Comparative example 1:

0.1% _O2 +99.9% _N2 roasting pretreatment, manganese-containing graphite used as high-performance adsorption material

A kind of recovery processing method of waste lithium-ion battery as shown in Figure 1, concrete steps are as follows:

S1: Lithium-ion battery discharge, put the waste lithium-ion battery into 10wt.% NaCl aqueous solution, soak for more than 48 hours to ensure complete discharge;

S2: The lithium-ion battery is broken, and the fully-discharged lithium-ion battery is mechanically broken to separate the positive electrode, negative electrode and other parts;

S3: Magnetic separation of lithium-ion batteries, the dismantled and broken batteries are subjected to magnetic separation to separate the iron in them;

S4: Secondary crushing of lithium-ion batteries, mechanically crushing the metal-containing battery materials used for subsequent processing after dismantling, and efficiently stripping the black powder from the current collector;

S5: Separation, separate the copper and aluminum foil metal, diaphragm and black powder in the crushed battery material pole piece, so that the black powder can reach a purity of 99.8%;

S6: low-oxygen roasting, the obtained black powder is placed in a roaster containing 0.5% oxygen by volume and the remainder is nitrogen, and roasted for 300 minutes, and cooled to room temperature after the reaction;

S7: acid leaching, the powder after roasting is put into 2mol/L sulfuric acid, after reacting for 180 minutes under the condition of 80 ℃, obtain lithium, nickel, cobalt leaching solution (leaching rate of lithium cobalt nickel is close to 100%, manganese leaching rate is about 20%) ), and the leaching residue containing manganese and graphite; the acid leaching effect is shown in a in Figure 7.

Comparative example 2:

21% _O2 +79% _N2 roasting pretreatment, manganese-containing graphite used as high-performance adsorption material

A kind of recovery processing method of waste lithium-ion battery as shown in Figure 1, concrete steps are as follows:

S1: Lithium-ion battery discharge, put the waste lithium-ion battery into 10wt.% NaCl aqueous solution, soak for more than 48 hours to ensure complete discharge;

S2: The lithium-ion battery is broken, and the fully-discharged lithium-ion battery is mechanically broken to separate the positive electrode, negative electrode and other parts;

S3: Magnetic separation of lithium-ion batteries, the dismantled and broken batteries are subjected to magnetic separation to separate the iron in them;

S4: Secondary crushing of lithium-ion batteries, mechanically crushing the metal-containing battery materials used for subsequent processing after dismantling, and efficiently stripping the black powder from the current collector;

S5: Separation, separate the copper and aluminum foil metal, diaphragm and black powder in the crushed battery material pole piece, so that the black powder can reach a purity of 99.8%;

S6: low-oxygen roasting, the obtained black powder is placed in a roaster containing 0.5% oxygen by volume and the remainder is nitrogen, and roasted for 300 minutes, and cooled to room temperature after the reaction;

S7: acid leaching, the powder after roasting is put into 2mol/L sulfuric acid, after reacting for 180 minutes under the condition of 80 ℃, obtain lithium, nickel, cobalt leaching solution (leaching rate of lithium cobalt nickel is close to 100%, manganese leaching rate is about 20%) ), and the leaching residue containing manganese and graphite; the acid leaching effect is shown in b in Figure 7.

The effect of acid leaching of valuable metals in Li-ion cathode materials pretreated in Comparative Example 1 (0.1% O ₂ ) and Comparative Example 2 (21% O ₂ ) is obviously worse than that of Examples 1-4, indicating that low-oxygen environment conditions are very critical during calcination. , Roasting under the condition of oxygen volume concentration of 0.5-1%, the effect of acid leaching of valuable metals is obviously better.

The method for selectively recovering positive electrode valuable metal elements and negative electrode graphite from waste lithium-ion batteries provided by the present invention and reusing them as high-performance adsorption catalytic materials has been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention, and the descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (9)

1. The recovery processing method of the waste lithium ion battery is characterized by comprising the following specific steps:

(1) Discharging the waste lithium ion battery;

(2) Crushing, magnetically separating and removing iron to obtain anode and cathode black powder;

(3) Roasting the anode black powder and the cathode black powder in a low-oxygen environment to obtain pretreated black powder;

(4) Adding the pretreated black powder into inorganic acid for acid leaching treatment to obtain leaching solution containing lithium, cobalt and nickel and residue containing manganese and graphite, wherein the leaching solution contains metal elements which are separated and recovered or are directly used for preparing a battery anode material, and the residue containing manganese and graphite which is used for preparing a catalytic material or an adsorption material.

2. The method for recycling waste lithium ion batteries according to claim 1, wherein in the step (1), the waste lithium ion batteries are cylindrical batteries.

3. The method for recycling waste lithium ion batteries according to claim 1, wherein the specific method in the step (1) is as follows: immersing the waste lithium ion battery in 5-20% sodium chloride or sodium sulfate aqueous solution for more than 48 hours, and drying.

4. The method for recycling waste lithium ion batteries according to claim 1, wherein the specific method in the step (2) is as follows: and (3) crushing the battery treated in the step (1) by using a hammer crusher, separating and removing iron by magnetic separation, peeling black powder from a battery current collector by using a pulverizer, and separating a diaphragm from the black powder by using a cyclone collecting hopper to obtain the anode and cathode black powder.

5. The method for recycling waste lithium ion batteries according to claim 1, wherein in the step (3), the low-oxygen environment condition is that the volume concentration of oxygen is 0.5-1%, and the mixed gas of oxygen and nitrogen is used; the roasting temperature is 600 ℃ and the roasting time is 60-300 minutes.

6. The method for recycling waste lithium ion batteries according to claim 1, wherein in the step (4), the inorganic acid is sulfuric acid solution of 0.5-3 mol/L, the solid-to-liquid ratio of acid leaching is 100g/L, the acid leaching temperature is 35-95 ℃, and the acid leaching time is 180-300 minutes.

7. The method for recycling waste lithium ion batteries according to claim 1, wherein in the step (4), any one of organic solvent extraction, chemical precipitation or electrodeposition is adopted for metal element separation.

8. The method for recycling waste lithium ion batteries according to claim 1, wherein in the step (4), the leaching solution containing lithium, cobalt and nickel is prepared again by solid synthesis after coprecipitation.

9. The method for recycling waste lithium ion batteries according to claim 1, wherein in the step (4), the treatment method of the residue containing manganese and graphite is selected from any one of the following:

(A) Separating by a floatation method to obtain manganese oxide and graphite, and regenerating the manganese oxide as a catalytic material;

(B) The residues containing manganese and graphite are directly reused as the adsorption material.

Images