KR20010107009A - Valuable metal extraction method from the exhausted li-ion secondary battery - Google Patents

Abstract

The present invention relates to a method for concentrating valuable metals from a waste lithium ion secondary battery in which a negative electrode and a positive electrode contained in a nickel-plated steel are packaged in a plastic package, the method comprising: first heating a lithium ion secondary battery at a predetermined temperature for a predetermined time; ; Cutting the lithium ion secondary battery to separate the positive and negative electrodes; Separating the electrode material remaining on the electrode by secondary heating and filtering the cut lithium ion secondary battery; And calcining the separated electrode material to concentrate valuable metals including cobalt and lithium. As a result, valuable metals and other parts can be separated and recycled, thereby reducing cost and preventing environmental pollution.

Description

Valuable METAL EXTRACTION METHOD FROM THE EXHAUSTED LI-ION SECONDARY BATTERY}

The present invention relates to a method for concentrating valuable metals from a lithium ion secondary battery, and more particularly, by concentrating valuable metals through heat treatment and classification processes and by recycling other parts separately, thereby reducing recycling costs. In addition, the present invention relates to a method for concentrating valuable metals from waste lithium ion secondary batteries capable of preventing environmental pollution.

Lithium-ion batteries are the lightest of the metals, and they use lithium, which holds the superior electrochemical position as the Group 1 metal on the periodic table, and has a high voltage and energy density as well as light weight. It is used as a power source for small portable equipment. Recently, lithium-ion batteries have been rapidly used as rechargeable batteries that can be recharged and reused as the use of expensive and compact electronic products such as mobile phones, camcorders, and notebook computers has increased.

The negative electrode and the positive electrode are each formed of a binder which mechanically connects the negative electrode active material, the positive electrode active material, the current collector, and each active material to the current collector. As the cathode active material, LiCoO _2, which has excellent reversibility, low self-discharge rate, high capacity, high energy density, and easy synthesis, is mainly used. As the cathode active material, carbon-based or graphite-based materials are used.

As a binder, polyvinylidene fluoride is used for both a negative electrode and a positive electrode, an aluminum film is used for the positive electrode collector, and a copper film is used for the negative electrode collector. The organic electrolyte solution (eg, ethylene carbonate, dimethylene carbonate, diethylene carbonate, etc.) is formed by dissolving lithium salt in an organic solvent.

The negative electrode, the positive electrode, the organic electrolyte, and the organic separator form a unit cell, and the lithium ion secondary battery is formed by combining one to several unit cells. In addition, a charge protection integrated circuit chip is installed in the lithium ion secondary battery to prevent explosion of lithium, and contains approximately 5-15 cobalt and 2-7 lithium.

Such a lithium ion secondary battery is an economical waste resource containing a large amount of valuable metals such as lithium and cobalt which are simple in appearance and relatively expensive. In addition, since it is a consumable having about 500 charge / discharge cycles and a life span of about 6 months to 2 years, the amount of waste is also increased with the increase in the amount used.

By the way, a small amount of metallic lithium may be generated in the negative electrode by overcharging or abnormal reduction in the waste lithium ion secondary battery, and the metallic lithium may explode rapidly when it meets moisture in the air. In addition, when the lithium salt or the electrolyte contained in the organic electrolyte is disposed in a landfill method like other batteries, there is a risk of serious soil contamination in the future, and cans and plastics used for the exterior of the battery are not easily disposed of. It is environmentally harmful.

On the other hand, conventionally, a method of extracting only the positive electrode active material having the largest specific gravity of constituent materials per cell from a lithium ion secondary battery and treating it with an acid and then using a metal component for plating is known, but such a method is complicated due to a complicated process and excessive cost. It is not commercialized.

Accordingly, it is necessary to search for a method for easily and safely extracting valuable metals such as lithium and cobalt from waste lithium ion secondary batteries and extracting and recycling each component.

Accordingly, an object of the present invention is to provide a method for enriching valuable metals from waste lithium ion secondary batteries that can reduce the cost cost and prevent environmental pollution by allowing the valuable metals and other components to be recycled separately from each other. To provide.

1 is a cross-sectional view of a lithium ion secondary battery,

2 is a flowchart of a sorting process of a lithium ion secondary battery according to the present invention;

3 is a schematic cross-sectional view of a high speed cutter for cutting a lithium ion secondary battery;

Figure 4 is a graph showing the results of the phase analysis by the X-ray diffraction analysis device of each electrode material after heat-treating the cut pieces of the lithium ion secondary battery,

Figure 5 is a graph showing the results of phase analysis of the calcined and concentrated cathode active material by X-ray diffraction analysis apparatus.

* Explanation of symbols for the main parts of the drawings

1 lithium ion secondary battery 2 unit battery

3: plastic package 4: charge protection integrated circuit chip

5: nickel coated steel 6: organic electrolyte

7: anode 8: organic separator

9: cathode 10: high speed cutter

11: charging part 13: cutting part

15: cutting piece chamber 17: classification unit

The object of the present invention relates to a method for concentrating valuable metals from a waste lithium ion secondary battery in which a negative electrode and a positive electrode contained in a nickel-plated steel are packaged in a plastic package according to the present invention. Tea heating; Cutting the lithium ion secondary battery to separate electrode materials of the positive electrode and the negative electrode; Separating the electrode material remaining on the electrode by secondary heating and filtering the cut lithium ion secondary battery; It is achieved by a valuable metal enrichment method from the waste lithium ion secondary battery, comprising the step of calcining the separated electrode material to separate and concentrate the positive electrode active material including cobalt and lithium.

Here, in the primary heating step, it is preferable to heat the lithium ion secondary battery for about 10 minutes to 1 hour in the temperature range of about 100 ~ 150 ℃.

Cutting the lithium ion secondary battery may be performed at a relative humidity of 10 or less to prevent oxidation of metal lithium.

By cutting the lithium ion secondary battery into cut pieces having a size of about 0.5 to 2.0 cm, the introduction of impurities can be prevented and the recovery rate of the electrode material can be improved.

On the other hand, the secondary heating step is preferably performed for about 30 minutes to 1 hour in the temperature range of about 300 ~ 600 ℃.

The filtering of the cut lithium ion secondary battery may be performed by vibrating sieve.

Separating the plastic package from the residues of the lithium ion secondary battery in which the electrode material is separated from other residues by specific gravity screening, and separating the nickel-coated steel from the residues from which the plastic package is separated by magnetic screening By further including, it is possible to recycle not only the electrode material but other materials.

On the other hand, the valuable metal further includes cobalt, it is possible to extract and recycle cobalt.

Organic impurities, organic separators, and carbons are volatilized and removed by the first heating, the second heating, and the calcining step, thereby removing organic impurities.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the present invention.

The waste lithium ion secondary battery used for a power supply, which has reached the end of its life or has failed to perform in the manufacturing stage, has one or several unit cells 2 in the plastic package 3 as shown in FIG. Packaged together with the charge protection integrated circuit chip (4).

The unit cell 2 contains a negative electrode 9, a positive electrode 7, an organic separator 8, and an organic electrolyte 6 in a nickel plated steel 5. In the negative electrode 9, graphite and carbon, which are negative electrode active materials, are coated on a copper plate by an organic binder, and in the positive electrode 7, LiCoO _{2, which} is a positive electrode active material, is coated on an aluminum plate by an organic binder. The organic electrolytic solution 6 is formed by dissolving lithium salt in an organic solvent formed of ethylene carbonate, dimethylene carbonate, diethylene carbonate, or a mixture thereof.

This waste lithium ion secondary battery 1 is recycled by a sorting process as shown in FIG. First, the waste lithium ion secondary battery 1 is first heat treated to cure the plastic package 3 to facilitate cutting (S10), thereby facilitating the separation of the unit cell 2 and by partial oxidation of metal lithium. Suppress the explosion. Then, the battery is cut into a predetermined size with the high speed cutter 10 as shown in FIG. 3 (S20).

The high speed cutter 10 includes a cutting portion having a funnel-shaped charging portion 11 for inserting the waste lithium ion secondary battery 1 and a rotary cutting blade for cutting the waste lithium ion secondary battery 1 ( 13) and the cutting piece chamber 15 in which the cutting piece of the waste lithium ion secondary battery 1 cut | disconnected by the cutting part 13 is accommodated in the up-down direction sequentially. In addition, a classification unit 17 having a sieve is provided between the cutting unit 13 and the cutting piece chamber 15 so as to selectively supply the cut waste lithium ion secondary battery 1 to the cutting piece chamber 15 according to the size. The sieve is vibrated to facilitate passage of the cutting piece. Here, the size of the cut pieces of the waste lithium ion secondary battery 1 may be determined by adjusting the mesh of the sieve.

When the waste lithium ion secondary battery 1 cut by the high speed cutter 10 is first classified (S30), the unit cell including the nickel-plated steel 5, the aluminum plate, and the copper plate in the plastic package 3 ( Part 2 of the electrode material, which is a powder, is separated. In the primary classification, excessive cutting is suppressed to minimize the incorporation of impurities into the electrode material. Then, the intermittent impact is cut within several times while maintaining a dehumidifying atmosphere of 10 or less relative humidity, thereby suppressing sudden oxidation of the metal lithium in two stages.

After the primary classification, the cut pieces classified by the primary classification are subjected to secondary heat treatment (S40). At this time, the bonding force of the organic binder is weakened, and the electrode material is powdered from the aluminum plate and the copper plate. Then, the powdered electrode material is separated by the vibrating body (S50), and the organic material including the organic electrolyte solution 6 and the organic separation membrane 8 is volatilized and removed by the secondary heat treatment.

The separated electrode material includes LiCoO ₂ , graphite, carbons, and an organic binder. Accordingly, by calcining the electrode material at a high temperature (S60), only carbon dioxide and the organic binder are burned and removed to selectively concentrate only LiCoO ₂ , a cathode active material which minimizes impurities. The selected LiCoO ₂ can be recovered by separating lithium and cobalt by conventional wet smelting methods.

Meanwhile, the plastic package 3, the nickel coated steel 5, the aluminum plate, and the copper plate remain as residues of the cut pieces from which the electrode material is separated, and the residues may be separated by specific gravity screening and magnetic screening. First, the plastic package 3 is separated by the specific gravity selection method (S70), and the nickel-coated steel 5 is separated from the aluminum and copper pieces by the magnetic separation method (S80).

Hereinafter, the present invention will be described in detail through preferred embodiments. Of course, the present invention is not limited only to the following examples.

Example

First, the waste lithium ion secondary battery 1 is heat-treated at 100 to 150 ° C. for about 10 minutes to 1 hour in air to cure the plastic package 3 of the waste lithium ion secondary battery 1 for easy cutting. At this time, the bonding strength of the organic binder is weakened, and the metallic lithium is partially oxidized to stabilize. Then, the high-speed cutter 10 of FIG. 3 is cut and subjected to primary classification, thereby partially disposing the electrode material as powder from the unit cell 2 including the nickel-plated steel 5 and the aluminum plate and the copper plate in the plastic package 3. Will be separated. At this time, by adjusting the mesh of the sieve installed in the high-speed cutter 10 classifier 17, it is possible to adjust the size of the cut piece of the waste lithium ion secondary battery (1).

The following Table 1 shows the recovery rate of the electrode material and the composition ratio by particle size according to the size of the cutting piece. As shown in the table, as the size of the cutting piece decreases, the recovery rate of the electrode material increases but the incorporation of impurities also increases. Can be. Therefore, since the electrode material can be recovered again during the secondary classification, it is desirable to focus on suppressing the incorporation of impurities during the primary classification. That is, it is preferable to set the size of the cut piece within a range that can satisfy both conditions such that the recovery rate of the electrode material is more than a certain level so that the mixing of impurities is small. cm may be suitable. When the primary classification is cut in a dehumidifying atmosphere of less than 10 relative humidity, the oxidation of the metal lithium does not occur.

Size of cut piece (cm) Recovery of Electrode Material () Component ratio by particle size after the first classification OVERSIZE UNDERSIZE Electrode material Etc Electrode material Etc 0.05 99 7 93 78 22 0.1 99 6 94 88 12 0.5 97 3 97 95 5 1.0 93 One 99 99 One 2.0 91.5 7 93 96 4 5.0 72 15 85 86 14 10.0 20 40 60 72 28

TABLE 1

After the primary classification is completed, the cut pieces cut into 0.5 to 2.0 cm are subjected to secondary heat treatment. Figure 4 shows the phase analysis results by the X-ray diffraction analysis device of each active material by heat-treating the cut pieces at a temperature of 300 ~ 700 ℃ in air for 30 minutes to 1 hour. As shown in FIG. 4, the separation of each active material is not performed at 300 ° C. or lower, and at 600 ° C. or higher, the aluminum plate and the copper plate are melted and mixed in the electrode material. Therefore, the secondary heat treatment is preferably carried out in the air in the temperature range of 300 ~ 500 ℃. By this secondary heat treatment, the electrode material is separated from the aluminum plate and the copper plate, and harmful organic substances such as the organic electrolyte solution 6 and the organic separation membrane 8 are volatilized and removed. Accordingly, the aluminum plate, the copper plate, the nickel coated steel 5, the plastic package 3, and the electrode material remain after the second heat treatment.

After the second heat treatment, when the vibrating sieve, which is the secondary classification, is performed for 5 to 30 minutes, the electrode material of 0.05 cm or less can be separated from the plastic package (3), nickel coated steel (5), aluminum plate and copper plate. have. Here, LiCoO ₂ and graphite and carbons are contained in the electrode material. Accordingly, to extract lithium and cobalt, the electrode material is calcined for 30 minutes to 1 hour in the temperature range of 700 ~ 900 ℃. 5 is a graph showing the results of phase analysis of the residue after calcining by an X-ray diffraction analyzer. As shown in FIG. 5, it can be seen that the LiCoO ₂ powder which minimizes the incorporation of impurities such as carbons and organic binders by calcination remains. The selected LiCoO ₂ can be concentrated by separating lithium and cobalt into oxides by conventional wet smelting.

Size of cut piece (cm) Recovery of Electrode Material () Component ratio by particle size after vibration sieve OVERSIZE UNDERSIZE Electrode material Etc Electrode material Etc 0.01 829 11 89 99 - 0.05 92 2 98 99 - 0.1 98 - 99 95 5 1.0 99 - 99 87 13 2.0 99 - 99 81 19

TABLE 2

In this way, the positive electrode active material is separated from the electrode material, and the remaining plastic package 3, the nickel-coated steel 5, the aluminum plate, and the copper plate can be separated from each other by specific gravity screening and magnetic screening. First, further grinding is performed to facilitate sorting, and then the plastic package 3 is extracted by specific gravity selection. Then, the ferromagnetic nickel-coated steel 5 can be separated using a magnet, and the copper plate and the aluminum plate, which are paramagnetic or nonmagnetic, can be separated.

As described above, in the present invention, by selecting the cathode active material by appropriate cutting and heat treatment, not only the valuable metals such as lithium and cobalt can be efficiently concentrated, but also the grinding cost can be reduced and the incorporation of impurities can be prevented as much as possible. In addition, other components, including plastic packages, nickel-coated steel, copper plates, aluminum plates, etc. are separated and recycled by gravity and magnetic screening.

As described above, according to the present invention, by allowing the valuable metal and other parts to be separated and recycled, it is possible not only to reduce the cost cost but also to prevent environmental pollution.

Claims (10)

In a method of concentrating valuable metals from a waste lithium ion secondary battery in which a negative electrode and a positive electrode contained in a nickel-plated steel are packaged in a plastic package, Primary heating the lithium ion secondary battery at a predetermined temperature for a predetermined time; Cutting the lithium ion secondary battery to separate electrode materials of the positive electrode and the negative electrode; Separating the electrode material remaining on the electrode by secondary heating and filtering the cut lithium ion secondary battery; And calcining the separated electrode material and separating and concentrating a positive electrode active material including cobalt and lithium. The method of claim 1, The primary heating step is a valuable metal concentration method from the waste lithium ion secondary battery, characterized in that for heating for about 10 minutes to 1 hour in the temperature range of about 100 ~ 150 ℃. The method of claim 1, The cutting of the lithium ion secondary battery may be carried out at a relative humidity of 10 or less to prevent oxidation of metal lithium. The method of claim 3, wherein The size of the cutting piece cut | disconnected the said lithium ion secondary battery is about 0.5-2.0 cm, The valuable metal concentration method from the waste lithium ion secondary battery characterized by the above-mentioned. The method of claim 1, The secondary heating step, the valuable metal concentration method from the waste lithium ion secondary battery, characterized in that performed for about 30 minutes to 1 hour in the temperature range of about 300 ~ 600 ℃. The method of claim 1, The filtering of the cut lithium ion secondary battery, the valuable metal concentration method from the waste lithium ion secondary battery, characterized in that performed by vibrating sieve. The method of claim 1, Separating the plastic package from the residue of the lithium ion secondary battery from which the electrode material is separated from the other residues by specific gravity screening, Valuable metal concentrate method from the waste lithium ion secondary battery. The method of claim 1, Separating the nickel-coated steel in the residue from which the plastic package is separated by a magnetic screening method of concentrating valuable metals from waste lithium ion secondary battery. The method of claim 1, The valuable metal is a method of concentrating valuable metals from waste lithium ion secondary battery, characterized in that it further comprises cobalt. The method according to any one of claims 1 to 9, The method of concentrating valuable metals from a waste lithium ion secondary battery, wherein the organic electrolyte, the organic separation membrane, and carbon are volatilized and removed by the first heating, the second heating and the calcining step.