KR20230089751A - Method for recovering valuable metals from cathodic active material of used lithium battery - Google Patents

Abstract

The present invention discloses a method for recovering valuable metals using a cathode material for a waste lithium ion battery. The present invention comprises the steps of culturing microorganisms in a solid medium; Inoculating and growing a liquid medium of microorganisms cultured on the solid medium; and adding a waste lithium ion battery cathode material and an organic compound to the liquid medium to decompose the waste lithium ion battery cathode material to obtain a leachate; and extracting and recovering the valuable metal included in the electrode of the waste lithium ion battery by filtering the leachate. In the step of obtaining the leachate, the valuable metal included in the cathode material for the waste lithium ion battery is reduced by the microorganisms and dissolved in the leachate.

Description

Method for recovering valuable metals using cathode materials for waste lithium ion batteries

The present invention relates to a method for recovering valuable metals using a cathode material for a waste lithium ion battery, and more particularly, the present invention relates to a method for recovering valuable metals by using microorganisms to reduce metal materials for a cathode material in a waste lithium ion battery using microorganisms such as Ni, Co, Mn, and Li. It relates to a method for recovering valuable metals using a cathode material for a waste lithium ion battery, which can decompose the cathode material in an economically/environmentally sustainable manner by making the cathode material into an aqueous solution.

Since lithium ion batteries have high energy density and light weight, they are used as a power source for small portable equipment, and recently, the usage of lithium ion batteries is rapidly increasing. In particular, in recent years, it has been widely used as a power source for hybrid electric vehicles (HEV/EV) as well as small home appliances and mobile products.

These lithium ion batteries are composed of a positive electrode, a negative electrode, an electrolyte, and a separator. Specifically, a plastic casing, a positive electrode, a negative electrode, a separator, an electrolyte, and a nickel-coated steel case included in several cell units. (Ni-coated steel casing).

On the other hand, the cathode of a lithium ion battery is composed of an active cathode material, a conductive agent, a binder, and a current collector. The cathode material has excellent reversibility, low self-discharge rate, high capacity, and high energy density. , lithium cobalt oxide (LiCoO ₂ ), which is easy to synthesize, is widely used.

In addition, recently, in order to reduce the amount of expensive cobalt (Co), a ternary lithium composite metal oxide such as Li(NiCoMn)Ox containing Ni and Mn is also used as a cathode material. However, since all of the above cathode materials contain at least 5% by weight of lithium and a large amount of valuable metals such as nickel, cobalt, and manganese, it is difficult to recover expensive valuable metals from cathode materials (cathode scrap) of waste lithium ion batteries. Attention is drawn to methods for

In addition, cathode materials for lithium ion batteries account for 40% of the total price of lithium ion batteries, and Li, Ni, and Co are considered as limited resources. These are the metals that will be sensitive to battery manufacturing.

In the future, a large amount of waste lithium ion batteries will be generated through battery replacement in electric vehicles, contact accidents, etc. When recycling, it is essential to recover cathode material metals. Since it is not an economically/environmentally sustainable technology, research on a method for recovering valuable metals from a cathode material for an economically/environmentally sustainable waste lithium ion battery is required.

Republic of Korea Patent Registration No. 1497041, "Method for recovering valuable metals from cathode materials of waste lithium ion batteries"

An embodiment of the present invention is a valuable metal using a waste lithium ion battery cathode material capable of recovering organic metals under neutral conditions of pH 7-8 by reducing valuable metals included in the waste lithium ion battery cathode material using microorganisms. We want to provide a recovery method.

That is, the embodiment of the present invention reduces the metal materials of the cathode material in the waste lithium ion battery using microorganisms to make Ni, Co, Mn, and Li into an aqueous solution, thereby decomposing the cathode material in an economically / environmentally sustainable manner. It is intended to provide a method for recovering valuable metals using a cathode material for a waste lithium ion battery.

A method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention includes culturing microorganisms in a solid medium; inoculating and growing the microorganisms cultured on the solid medium in a liquid medium; and adding a waste lithium ion battery cathode material and an organic compound to the liquid medium to decompose the waste lithium ion battery cathode material to obtain a leachate; and extracting and recovering valuable metals included in the electrode of the waste lithium ion battery by filtering the leachate, wherein the step of obtaining the leachate comprises It is reduced by the microorganisms and dissolved in the leachate.

The step of adding a waste lithium ion battery cathode material and an organic compound to the liquid medium to decompose the waste lithium ion battery cathode material to obtain a leachate may be performed under anaerobic conditions.

The liquid medium may be pH 7 to pH 8.

The positive electrode material is LiCoO ₂ , LiNiO ₂ , LiNi _x Mn _y O ₂ , LiNi _x Co _y O ₂ , Li _1+z Ni _x M _ny Co _1-xy O ₂ , LiNi _x Co _y Al _z O ₂ , LiV ₂ O ₅ , LiTiS ₂ , LiMoS ₂ , LiMnO ₂ , LiCrO ₂ , LiMn ₂ O ₄ , LiFeO ₂ and LiFePO ₄ , including at least one of (x is 0.3 to 0.8, y is 0.1 to 0.45, z is 0 to 0.2).

The microorganism may include a microorganism capable of reducing a metal under anaerobic conditions including at least one of Shewanella, Alteromonas and Geobacter.

The organic compound may include at least one of acetate, sodium lactate, natural organic matter, and sludge.

According to an embodiment of the present invention, valuable metals included in the waste lithium ion battery cathode material are reduced using microorganisms, thereby using a waste lithium ion battery cathode material capable of recovering organic metals under neutral conditions of pH 7-8. A valuable metal recovery method can be provided.

That is, according to an embodiment of the present invention, by reducing the metal materials of the cathode material in the waste lithium ion battery using microorganisms to make Ni, Co, Mn, and Li into an aqueous solution, the cathode material is economically / environmentally sustainable It is possible to provide a valuable metal recovery method using a waste lithium ion battery cathode material that can be decomposed into.

1 is a schematic diagram showing a method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention.
2 is a flowchart illustrating a method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings and the contents described in the accompanying drawings, but the present invention is not limited or limited by the embodiments.

Terminology used herein is for describing the embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" and/or "comprising" does not exclude the presence or addition of one or more other elements or steps in a stated component or step.

As used herein, “embodiments,” “examples,” “aspects,” “examples,” and the like should not be construed as indicating that any aspect or design described is preferred or advantageous over other aspects or designs. It is not.

Also, the term 'or' means 'inclusive or' rather than 'exclusive or'. That is, unless otherwise stated or clear from the context, the expression 'x employs a or b' means any one of the natural inclusive permutations.

Also, the singular expressions “a” or “an” used in this specification and claims generally mean “one or more,” unless indicated otherwise or clear from context to refer to the singular form. should be interpreted as

The terms used in the description below have been selected as general and universal in the related technical field, but there may be other terms depending on the development and / or change of technology, convention, preference of technicians, etc. Therefore, terms used in the following description should not be understood as limiting technical ideas, but should be understood as exemplary terms for describing the embodiments.

In addition, in certain cases, there are also terms arbitrarily selected by the applicant, and in this case, their meanings will be described in detail in the corresponding description section. Therefore, terms used in the following description should be understood based on the meaning of the term and the contents throughout the specification, not simply the name of the term.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

Meanwhile, in the description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, the terminology used in this specification is a term used to appropriately express the embodiment of the present invention, which may vary according to the intention of a user or operator or customs in the field to which the present invention belongs. Therefore, definitions of these terms will have to be made based on the content throughout this specification.

1 is a schematic diagram showing a method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention, and FIG. 2 is a method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention. It is a flow chart showing

A method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention includes culturing microorganisms in a solid medium (S110), inoculating and growing microorganisms cultured in a solid medium in a liquid medium (S120) and adding a waste lithium ion battery cathode material and an organic compound to a liquid medium to decompose the waste lithium ion battery cathode material to obtain a leach solution (S130) and filtering the leach solution to remove valuable metals included in the electrode of the waste lithium ion battery. It includes extracting and recovering (S140).

Therefore, in the method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention, metal materials for a cathode material in a waste lithium ion battery are reduced using microorganisms to make Ni, Co, Mn, and Li into an aqueous solution. This makes it possible to decompose the cathode material in an economically/environmentally sustainable way.

First, in the method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention, a step of culturing microorganisms in a solid medium (S110) is performed.

The microorganism is a bacterium capable of reducing metal ions, for example, the microorganism may be a microorganism capable of reducing metal under anaerobic conditions, preferably, the microorganism is Shewanella, Alteromonas ) and at least one of Geobacter.

Cultivation can be carried out under dark conditions at a temperature of 20 ° C to 35 ° C, and when the culture temperature is out of the above range (less than 20 ° C or greater than 35 ° C), there is a problem that microorganisms do not grow.

In addition, the step of culturing the microorganisms in the solid medium (S110) may proceed in a state exposed to air.

Microorganisms that can reduce metals under anaerobic conditions can obtain electrons from organic compounds instead of breathing oxygen, and can reduce the electrons obtained from organic compounds to surrounding metal oxides (eg, waste lithium ion battery cathode materials).

For example, culture was performed in PYE medium (1.0 g/L peptone, 1.5 g/L yeast extract, 7.5 g/L NaCl, and 1.0 g/L (NH4)2SO4 in DI water with 10 mM HEPES buffer (pH 7.5)).

Thereafter, in the method for recovering valuable metals using the cathode material for a waste lithium ion battery according to an embodiment of the present invention, a step of inoculating and growing microorganisms cultured in a solid medium in a liquid medium (S120) is performed.

The method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention inoculates and grows microorganisms cultured in a solid medium in a liquid medium, thereby increasing the growth rate and activity of microorganisms compared to initially growing microorganisms in a liquid. can be improved.

In the method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention, the pH of the liquid medium may be between pH 7 and pH 8, and when the pH is out of the above-mentioned range (if it is less than pH 7 or pH 8 If it exceeds), it may cause problems in growth during microbial culture.

Therefore, in the method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention, the valuable metal contained in the cathode material for a waste lithium ion battery is reduced using microorganisms, thereby organically recovering the valuable metal under neutral conditions of pH 7-8. By decomposing the metal, it is economically and environmentally sustainable than the strong acid or heat treatment method used for the decomposition of the existing cathode material.

Thereafter, the method for recovering valuable metals using the waste lithium ion battery cathode material according to an embodiment of the present invention includes adding a waste lithium ion battery cathode material and an organic compound to a liquid medium to decompose the waste lithium ion battery cathode material to obtain a leachate. Step S130 is performed.

In the method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention, in the step of obtaining a leachate (S130), the valuable metals included in the cathode material for a waste lithium ion battery are reduced by microorganisms and dissolved in the leachate. can

Under aerobic conditions, microorganisms breathe using oxygen and gain electrons, but under anaerobic conditions, microorganisms obtain electrons from organic compounds and can transfer them to metal oxides after metabolic processes. Through this, in the method for recovering valuable metals using the positive electrode material for a waste lithium ion battery according to an embodiment of the present invention, valuable metals can be reduced under anaerobic conditions.

More specifically, electrons are generated during the metabolic process of microorganisms under anaerobic conditions, and these electrons convert Ni, Co, and Mn, which are oxidized in the cathode material, to Ni(II), Co(II), and Mn(II). ) and can exist in an aqueous solution, or only specific valuable metals among Ni, Co, and Mn can be reduced, and the cathode material can be decomposed while breaking down the structure of the cathode material.

The step of decomposing the waste lithium ion battery cathode material by adding the waste lithium ion battery cathode material and an organic compound to the liquid medium to obtain a leachate (S130) may be performed under anaerobic conditions.

Anaerobic conditions may be formed by blocking oxygen and injecting at least one of nitrogen gas (N ₂ ) and argon (Ar) gas.

If the process proceeds under an environment other than anaerobic conditions, the recovery rate of valuable metals present in the leachate may be lowered because the microorganisms proceed with microbial respiration using oxygen in the air.

However, since the method for recovering valuable metals using a waste lithium ion battery cathode material according to an embodiment of the present invention decomposes the waste lithium ion battery cathode material in a liquid medium under anaerobic conditions to obtain a leachate, the metabolic respiration of microorganisms uses oxygen. Since it is made in the form of reducing valuable metals without doing so, the recovery rate of valuable metals can be improved.

More specifically, under anaerobic conditions, microorganisms may obtain electrons from organic compounds, and the microorganisms may release the obtained electrons back to metal oxides.

The concentration of microorganisms in the leachate may be 10 ⁸ cells / ml to 10 ¹⁰ cells / ml, and when the concentration of microorganisms is out of the above range (if less than 10 ⁸ cells / ml or greater than 10 ¹⁰ cells / ml), microorganisms There is a problem of not having this sufficient activity.

The decomposition temperature of decomposing the waste lithium ion battery cathode material by adding the waste lithium ion battery cathode material and an organic compound to the liquid medium to obtain a leachate (S130) may be performed at room temperature.

After the waste lithium ion battery cathode material has already been decomposed, there is no problem under normal temperature conditions (20±5℃). reactions can occur.

The cathode material is LiCoO ₂ , LiNiO ₂ , LiNi _x Mn _y O ₂ , LiNi _x Co _y O ₂ , Li _1+z Ni _x M _ny Co _1-xy O ₂ , LiNi _x Co _y Al _z O ₂ , LiV ₂ O ₅ , LiTiS ₂ , LiMoS ₂ , LiMnO ₂ , LiCrO ₂ , LiMn ₂ O ₄ , LiFeO ₂ and LiFePO ₄ , including at least one of (x is 0.3 to 0.8, y is 0.1 to 0.45, z is 0 to 0.2).

The organic compound may include at least one of acetate, sodium lactate, natural organic matter, and sludge.

Organic compounds are substances that donate electrons for respiration of microorganisms under anaerobic conditions, and microorganisms can metabolize through organic compounds.

Thereafter, in the method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention, a step (S140) of extracting and recovering valuable metals included in the electrode of the waste lithium ion battery by filtering the leachate is performed.

Extracting and recovering the valuable metal (S140) may be performed through a syringe filter.

The valuable metal decomposed and reduced by microorganisms may include at least one of nickel (Ni), cobalt (Co), manganese (Mn), and lithium (Li).

In the method for recovering valuable metals using a cathode material for a waste lithium ion battery according to an embodiment of the present invention, the recovery rate of valuable metals may be 20% to 50%.

Example 1

Shuwa in PYE medium (1.0 g/L peptone, 1.5 g/L yeast extract, 7.5 g/L NaCl, and 1.0 g/L (NH ₄ ) ₂ SO ₄ in DI water with 10 mM HEPES buffer (pH 7.5)) NMC622 anode in PYE solution with Shewanella bacteria when the OD value is approximately 1.2-1.5 (at 600 nm) through UV-Vis measurement after culturing Shewanella bacteria Add ash and 15 mM sodium lactate together. After this, the air is cut off and an anaerobic condition is made by filling with N ₂ gas.

Example 2

Shuwa in PYE medium (1.0 g/L peptone, 1.5 g/L yeast extract, 7.5 g/L NaCl, and 1.0 g/L (NH ₄ ) ₂ SO ₄ in DI water with 10 mM HEPES buffer (pH 7.5)) NMC811 anode in PYE solution containing Shewanella bacteria when the OD value is approximately 1.2-1.5 (at 600 nm) through UV-Vis measurement after culturing Shewanella bacteria Add ash and 15 mM sodium lactate together. After this, the air is cut off and an anaerobic condition is made by filling with N ₂ gas.

Experimental example

As the reaction time passed through ICP-MS, the amount of the dissolved cathode material was measured by measuring the concentrations of Ni, Co, and Mn detected in the solution.

Table 1 is a table showing concentrations and ratios of valuable metals decomposed in a solution through a method for recovering valuable metals using the waste lithium ion battery cathode materials according to Examples 1 and 2 analyzed through ICP-MS.

Example 1 (NMC622) Example 2 (NMC811) Mn (ppb) 1867.97 461.87 Co(ppb) 2803.81 510.11 Ni (ppb) 9439.46 5093.10 Ratio of dissolved Ni, Co and Mn 0.5131 0.2205 Mn wt/total(Ni+Co+Mn)wt 0.1 0.1 Co wt/total(Ni+Co+Mn)wt 0.2 0.1 Ni wt/total(Ni+Co+Mn)wt 0.7 0.8

Referring to Table 1, it can be seen that the valuable metals can be easily recovered through reduction by microorganisms at a neutral pH of 7 through the method for recovering valuable metals using the cathode material for a waste lithium ion battery according to an embodiment of the present invention. there is.

In addition, as can be seen in Table 1, the ratio of dissolved ni, Co, and Mn (recovery rate) of nickel, cobalt, and manganese is approximately ~50% in the case of Example 1 (NMC 622), In the case of Example 2 (NMC 811), it can be seen that it represents approximately ~22%.

As described above, although the present invention has been described by the limited embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art in the field to which the present invention belongs can make various modifications and variations from these descriptions. this is possible Therefore, the scope of the present invention should not be limited to the described embodiments and should not be defined, and should be defined by not only the claims to be described later, but also those equivalent to these claims.

Claims (6)

Cultivating microorganisms in a solid medium;
inoculating and growing the microorganisms cultured on the solid medium in a liquid medium; and
adding a waste lithium ion battery cathode material and an organic compound to the liquid medium to decompose the waste lithium ion battery cathode material to obtain a leachate; and
extracting and recovering valuable metals included in the electrode of the waste lithium ion battery by filtering the leachate;
including,
In the step of obtaining the leachate, the valuable metal contained in the cathode material for the waste lithium ion battery is reduced by the microorganisms and dissolved in the leachate.
According to claim 1,
The step of decomposing the waste lithium ion battery cathode material by adding the waste lithium ion battery cathode material and an organic compound to the liquid medium to obtain a leachate,
A method for recovering valuable metals using a cathode material for a waste lithium ion battery, characterized in that it proceeds under anaerobic conditions.
According to claim 1,
The liquid medium is a valuable metal recovery method using a waste lithium ion battery cathode material, characterized in that pH 7 to pH 8.
According to claim 1,
The positive electrode material is LiCoO ₂ , LiNiO ₂ , LiNi _x Mn _y O ₂ , LiNi _x Co _y O ₂ , Li _1+z Ni _x M _ny Co _1-xy O ₂ , LiNi _x Co _y Al _z O ₂ , LiV ₂ O ₅ , LiTiS ₂ , LiMoS ₂ , LiMnO ₂ , LiCrO ₂ , LiMn ₂ O ₄ , LiFeO ₂ and LiFePO ₄ , including at least one of (x is 0.3 to 0.8, y is 0.1 to 0.45, z is A method for recovering valuable metals using a cathode material for a waste lithium ion battery, characterized in that 0 to 0.2).
According to claim 1,
Wherein the microorganism comprises a microorganism capable of reducing metal under anaerobic conditions including at least one of Shewanella, Alteromonas and Geobacter Waste lithium ion battery characterized in that Valuable metal recovery method using cathode material.
According to claim 1,
The organic compound is a valuable metal recovery method using a waste lithium ion battery cathode material, characterized in that it contains at least one of acetate, sodium lactate, natural organic matter and sludge.

Images