CN105186058A - Method for environmentally-friendly resource recycling of lithium ion battery electrodes - Google Patents

Abstract

The invention discloses a method for resourceful and environmentally friendly recycling of lithium-ion battery electrodes. The method is to put the lithium-ion battery electrodes into a high-temperature liquid, detach the electrode material from the electrode current collector, and enter the high-temperature liquid. Then add water to the high-temperature liquid, dissolve and filter to obtain a filter cake containing only electrode current collectors and a mixed filtrate containing high-temperature liquid and electrode materials; or, filter to obtain a mixture filter cake containing electrode materials and electrode current collectors Liquid filtrate; the temperature of the high-temperature liquid is not lower than the separation or decomposition temperature of the binder used to bond and fix the electrode material, and the electrode is positive or negative. The method of the invention has the advantages of high separation efficiency, simple process, environmental protection, low cost, etc., and can solve the problems of pollution and recycling of waste lithium ion battery electrodes.

Description

A method for resourceful and environmentally friendly recycling of lithium-ion battery electrodes

technical field

The invention relates to a battery recovery method, in particular to a method for resourceful and environmentally friendly recovery of lithium-ion battery electrodes.

Background technique

Nowadays, as more and more electronic products are scrapped, the amount of scrapped lithium-ion battery electrodes used in electronic products is also increasing. How to recycle lithium-ion battery electrodes in a resourceful and environmentally friendly manner is becoming more and more important. In the prior art, there are related recycling technologies for lithium-ion battery electrodes, such as: Chinese patent application CN01130735.8, the invention titled "Method for recovering metals from waste lithium-ion batteries" discloses a recycling method, Although this invention can also achieve the purpose of recycling the metals, it uses high-temperature furnace roasting in the recycling process, and also uses the means of adding acid to dissolve, which not only produces new environmental pollution in the recycling process, but also has high costs and complicated processes. , not suitable for large-scale recycling requirements! Therefore, the development of a high-efficiency, pollution-free, and low-cost recycling method for lithium-ion battery electrodes will be of great value and social significance to solve the pollution and recycling of waste lithium-ion battery electrodes.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art, and provide a resource-based and environmentally friendly recycling method for lithium-ion battery electrodes with high separation efficiency, simple process, no pollution, and low cost.

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

A resource-based and environmentally friendly recycling method for lithium-ion battery electrodes, wherein the lithium-ion battery electrodes include electrode materials and electrode collectors; the method is to put the lithium-ion battery electrodes into high-temperature liquid, and use the high-temperature liquid to The electrode material is separated from the electrode collector, and then water is added to the high-temperature liquid for dissolution and filtration to obtain a filter cake containing only the electrode collector and a mixed filtrate containing high-temperature liquid and electrode materials; the obtained filter cake is washed and dried dry to obtain the electrode current collector; perform secondary filtration on the mixed filtrate containing high-temperature liquid and electrode material to obtain a filter cake containing electrode material and filtrate containing high-temperature liquid; the temperature of the high-temperature liquid is not lower than that used for viscosity The separation or decomposition temperature of the binder that connects and fixes the electrode material, and the electrode is positive or negative.

Another method for resourceful and environmentally friendly recovery of lithium-ion battery electrodes, the lithium-ion battery electrodes include electrode materials and electrode collectors; the method is to put the lithium-ion battery electrodes into a high-temperature liquid, and pass through the high-temperature liquid The heating action makes the electrode material detach from the electrode current collector, and then add water to the high temperature liquid for dissolution and filtration to obtain a mixture filter cake containing electrode material and electrode current collector and a filtrate containing high temperature liquid; for the obtained mixture filter cake After cleaning and drying, sieving treatment is carried out to obtain separated electrode materials and electrode collectors; the temperature of the high-temperature liquid is not lower than the separation or decomposition temperature of the adhesive used to bond and fix the electrode materials, and the Described electrode is positive pole or negative pole.

Since the electrode material is in the form of powder, and the electrode collector is in the form of particles or flakes, the above two solutions can be realized by adjusting the mesh size of the filter.

The method for resourceful and environmentally friendly recycling of lithium-ion battery electrodes according to the present invention also has the following improvements:

1. An isolation net is set in the container holding the high temperature liquid. The isolation net can intercept the granular or sheet-like electrode collectors and only allow the powdery electrode materials to pass through. The separated electrode collectors can be directly obtained by taking the isolation net out of the container, which can improve work efficiency.

2. The high-temperature liquid is molten salt. Because molten salt has stable performance at high temperature, low cost and high safety.

3. The molten salt is a chloride salt or a mixed salt of chloride salt. Because the price of chloride salt is cheap, such as sodium chloride, calcium chloride, etc., the source of raw materials is extensive.

4. The high-temperature liquid does not react chemically with the electrode material and the electrode collector, so as to ensure the purity and reuse value of the recovered product.

5. When the obtained electrode material is a positive electrode material, the remaining binder is decomposed and removed by heating and oxidation. Because the positive electrode material obtained by separation will have some binder or the decomposition residue of the binder such as carbon, etc., it can be converted into carbon dioxide and volatilized by high-temperature oxidation treatment, thereby improving the purity of the obtained positive electrode material such as lithium salt. Of course, oxygen can be added during high temperature oxidation treatment to improve the effect of oxidation treatment.

6. When the electrode current collector is aluminum foil, the temperature of the high-temperature liquid is higher than the melting point of aluminum. Because the thickness of the aluminum foil is very thin, it is recycled in the air by conventional methods, such as heating and recycling, which is easy to oxidize, and the recovery rate is low, resulting in waste of resources. When the temperature of the high-temperature liquid is higher than the melting point of aluminum, the aluminum foil will be melted into aluminum particles. When the aluminum particles are melted and recycled, it has the advantages of low loss and high yield, thereby increasing its recycling value.

7. Evaporating and concentrating the filtrate containing high-temperature liquid to recycle high-temperature liquid.

Compared with the prior art, the present invention has the following beneficial effects:

1. Environmental protection: In the recycling process, no waste water, waste gas and waste residue are produced.

2. Recycling: the electrode collectors and electrode materials are recycled.

3. Low cost: Since no chemicals are added and consumed during the entire recycling process, the recycling cost is low.

Description of drawings

FIG. 1 is a flow chart of a resource-based and environmentally-friendly recovery of the positive electrode of a lithium-ion battery provided in Example 1.

Fig. 2 is a flow chart of a resource-based and environmentally-friendly recovery of lithium-ion battery negative electrodes provided in Example 2.

Fig. 3 is another process flow diagram for resource-based and environmentally-friendly recovery of the positive electrode of lithium-ion batteries provided in Example 3.

Fig. 4 is another process flow diagram for resource-based and environmentally-friendly recovery of lithium-ion battery negative electrodes provided in Example 4.

Detailed ways

Below in conjunction with embodiment and accompanying drawing, technical scheme of the present invention is described in further detail:

Example 1

Referring to Fig. 1 : a process flow for resourceful and environmentally friendly recovery of the positive electrode of lithium-ion batteries provided in this embodiment is as follows: put the positive electrode of lithium-ion batteries into a high-temperature liquid, and the temperature of the high-temperature liquid is greater than the melting point of aluminum ; Through the heating of the high-temperature liquid, the aluminum foil of the positive electrode current collector is melted, and the positive electrode material such as lithium cobaltate adhering to the positive electrode current collector will break away and enter the high-temperature liquid; add water to the high-temperature liquid, and pass through the water. Dissolve to form an aqueous solution, and perform one-time filtration. The so-called one-time filtration is to control the mesh size of the filter screen so that the positive electrode material can be filtered but the aluminum particles cannot be filtered, and the aluminum particle filter cake and the mixed filtrate containing the positive electrode material and high-temperature liquid are obtained; Clean and dry the filter cake of aluminum particles to obtain aluminum blocks; perform secondary filtration on the mixed filtrate to obtain filter cakes containing positive electrode materials such as lithium salts and filtrates containing high-temperature liquids; wash and dry the filter cakes, and then Heating and oxidation treatment can obtain high-content positive electrode materials, such as lithium cobaltate powder; the filtrate containing high-temperature liquid can be evaporated and concentrated, and high-temperature liquid can be recovered for recycling.

Example 2

Referring to Fig. 2, a process flow for resource-based and environmentally friendly recovery of lithium-ion battery negative electrodes provided by this embodiment is as follows: add lithium-ion battery negative electrodes to high-temperature liquids, and the temperature of high-temperature liquids is generally controlled at 450° C. to 700° C. ℃, at this temperature, the binder bonding the negative electrode material can be decomposed, causing the negative electrode material attached to the negative electrode current collector to detach and enter the high-temperature liquid; add water to the high-temperature liquid, through the water Dissolution, forming an aqueous solution, and performing a filtration to obtain a filter cake containing the negative electrode collector and a mixed filtrate containing the negative electrode material and high-temperature liquid. It cannot be filtered; after cleaning and drying the filter cake containing the negative electrode current collector, the negative electrode current collector, such as copper foil, is obtained; the mixed filtrate is filtered twice to obtain the filter cake containing the negative electrode material and the high temperature liquid. Filtrate; washing and drying the filter cake to obtain the negative electrode material; evaporating and concentrating the filtrate containing high-temperature liquid, which can be recovered to obtain high-temperature liquid for recycling.

Example 3

Referring to FIG. 3 , another process flow for resourceful and environmentally friendly recycling of the positive electrode of the lithium-ion battery provided in this embodiment is as follows: the positive electrode of the lithium-ion battery is put into a high-temperature liquid, and the temperature of the high-temperature liquid is higher than the melting point of aluminum; Through the heating of the high-temperature liquid, the aluminum foil of the positive electrode current collector is melted, so that the lithium salt of the positive electrode material such as lithium cobalt oxide adhered to the positive electrode current collector is detached and enters the high-temperature liquid; water is added to the high-temperature liquid, and the water passes through the high-temperature liquid. The solution is dissolved to form an aqueous solution, and filtered to obtain a mixture filter cake containing positive electrode material and positive electrode current collector and a filtrate containing high-temperature liquid; the obtained mixture filter cake is cleaned and dried before sieving; since the positive electrode material is powder , and the size and specific gravity of the aluminum particles of the positive electrode current collector are different, so the two can be separated by sieving to obtain aluminum particles and fine powder; the fine powder is heated and oxidized to oxidize the residual binder into carbon dioxide Volatilization means obtaining high-content positive electrode materials, such as lithium cobaltate powder; evaporating and concentrating the filtrate containing high-temperature liquid, which can be recycled to obtain high-temperature liquid for recycling.

Example 4

Referring to Figure 4, another process flow for resource-based and environmentally-friendly recovery of lithium-ion battery negative electrodes provided by this embodiment is as follows: add lithium-ion battery negative electrodes to high-temperature liquids, and the temperature of high-temperature liquids is generally controlled at 450°C~ Between 700°C, at this temperature, the binder bonding the negative electrode material can be decomposed, and the negative electrode material attached to the negative electrode can be separated from the negative electrode current collector and enter the high-temperature liquid; add water to the high-temperature liquid , through the dissolution of water, an aqueous solution is formed, filtered to obtain a mixture filter cake containing negative electrode materials and negative electrode current collectors and a filtrate containing high-temperature liquid; the obtained mixture filter cake is cleaned and dried before screening; due to The negative electrode material is in the form of powder, which is different in size and specific gravity from the negative electrode current collector copper foil, so the two can be separated by sieving to obtain separated copper foil and negative electrode material; the filtrate containing high-temperature liquid is evaporated and concentrated. High temperature liquid can be recovered for recycling.

Finally, it is necessary to explain here that: the above examples are only used to further describe the technical solutions of the present invention in detail, and cannot be interpreted as limiting the protection scope of the present invention. Non-essential improvements and adjustments all belong to the protection scope of the present invention.

Claims (9)

1. lithium ion cell electrode is carried out to a method for resource environmental protection recovery, described lithium ion cell electrode comprises electrode material and electrode current collecting body; It is characterized in that: described method is that lithium ion cell electrode is put into high-temp liquid, by the heat effect of high-temp liquid, electrode material is separated from electrode current collecting body, then in high-temp liquid, water is added, carry out dissolution filter, obtain only containing the filter cake of electrode current collecting body and containing the mixing filtrate of high-temp liquid and electrode material; Cleaning, drying is carried out to the filter cake obtained, namely obtains electrode current collecting body; Secondary filter is carried out to the mixing filtrate containing high-temp liquid and electrode material, namely obtains the filter cake containing electrode material and the filtrate containing high-temp liquid; The temperature of described high-temp liquid is not less than separation for the bonding agent of the electrode material that is adhesively fixed or decomposition temperature, and described electrode is negative or positive electrode.

2. lithium ion cell electrode is carried out to a method for resource environmental protection recovery, described lithium ion cell electrode comprises electrode material and electrode current collecting body; It is characterized in that: described method is that lithium ion cell electrode is put into high-temp liquid, by the heat effect of high-temp liquid, electrode material is separated from electrode current collecting body, then in high-temp liquid, water is added, carry out dissolution filter, obtain the mixture filter cake containing electrode material and electrode current collecting body and the filtrate containing high-temp liquid; Carry out screening process after cleaning, drying is carried out to the mixture filter cake obtained again, namely obtain electrode material and the electrode current collecting body of separation; The temperature of described high-temp liquid is not less than separation for the bonding agent of the electrode material that is adhesively fixed or decomposition temperature, and described electrode is negative or positive electrode.

3. method as claimed in claim 1 or 2, is characterized in that: in the container holding high-temp liquid, be provided with separation net.

4. method as claimed in claim 1 or 2, is characterized in that: described high-temp liquid is fuse salt.

5. method as claimed in claim 4, is characterized in that: described fuse salt is the salt-mixture of chlorate or chlorate.

6. method as claimed in claim 1 or 2, is characterized in that: described high-temp liquid and electrode material and electrode current collecting body all chemical reaction do not occur.

7. method as claimed in claim 1 or 2, is characterized in that: when the electrode material obtained is positive electrode, makes the bonding agent wherein remained decompose removing by heated oxide.

8. method as claimed in claim 1 or 2, is characterized in that: when described electrode current collecting body is aluminium foil, and the temperature of described high-temp liquid is higher than the fusing point of aluminium.

9. method as claimed in claim 1 or 2, is characterized in that: carry out evaporation and concentration to the filtrate containing high-temp liquid, to recycle high-temp liquid.