KR20110060040A - Method for making nano-particle from spent lithium ion batteries - Google Patents

Abstract

PURPOSE: A nanopowder producing method from waste lithium ion batteries is provided to heat-treating a metal ion solution obtained from the waste lithium ion batteries. CONSTITUTION: A nanopowder producing method from waste lithium ion batteries comprises the following steps: separating a metal ion solution from the waste lithium ion batteries(S100); spraying the metal ion solution in a micro-droplets(S200); passing the micro-droplets through fire for obtaining the nanopowder(S300); and heat processing the obtained nanopowder at 700~1,000deg C(S400). The metal ion solution is obtained from a positive electrode active material.

Description

Method of manufacturing nano powder from waste lithium ion battery {METHOD FOR MAKING NANO-PARTICLE FROM SPENT LITHIUM ION BATTERIES}

The present invention relates to a method for producing nanopowders from waste lithium ion batteries.

Lithium-ion batteries have the most optimal characteristics for mobile IT and future automotive applications. Lithium-ion batteries are suitable in these two fields because they can be used without intermittent and repetitive charging without any loss of performance in a range of specific states of charge.

As the demand rises, the amount of waste lithium-ion batteries discarded is expected to increase exponentially every year.

There are various valuable metals in the lithium ion battery including the positive electrode active material, but these metals are not properly recovered and disposed of.

It is an object of the present invention to provide a method for producing useful nanopowders from spent lithium ion batteries.

An object of the present invention is to obtain a step of separating the metal component in the waste lithium ion battery; Acid leaching the metal component in a reducing component atmosphere to obtain a metal ion aqueous solution; Spraying the aqueous metal ion solution into microdroplets; And it can be achieved by a method for producing a nano-powder from a waste lithium ion battery comprising the step of passing the microdroplets through a flame to obtain a nano powder.

The metal component may be obtained from a cathode active material.

The method may further include heat treating the nano powder.

The heat treatment may be performed while supplying oxygen at 700 ° C to 1000 ° C.

The nano powder may be a ternary cathode active material including lithium, cobalt, nickel and manganese.

The obtaining of the positive electrode active material component may include: pulverizing a positive electrode plate in which the positive electrode active material is fixed using an organic binder; Heat-treating the pulverized positive electrode plate and the positive electrode active material to remove the organic binder; And separating the positive electrode plate and the positive electrode active material by a second crushing after heat treatment.

The flame-generating flame apparatus includes five concentric tubes, and may be supplied from a central tube in the order of a transport gas and the microdroplets, inert gas, hydrogen, oxygen, and air.

The acid leaching may use nitric acid, and the reduction may use hydrogen peroxide.

The object is to obtain a ternary positive electrode active material from a waste lithium ion battery; Acid leaching the ternary cathode active material in a reducing component atmosphere to obtain a metal ion aqueous solution; Preparing a nanopowder by spraying the aqueous metal ion solution using ultrasonic waves, followed by flame treatment; And it can also be achieved by a method for producing a nano-powder from the waste lithium ion battery comprising the step of heat-treating the nano-powder at 700 ℃ to 1000 ℃.

The ternary cathode active material may be LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ .

According to the present invention, useful nanopowders can be obtained from waste lithium ion batteries.

Figure 1 shows a method for producing a nano-powder from the waste lithium ion battery according to the present invention.

First, a metal component is recovered from the waste lithium ion battery (S100). This process may include the grinding (cutting) process of the waste lithium ion battery, and the grinding may be performed several times. When recovering the positive electrode active material fixed to the aluminum foil, which is a positive electrode current collector (anode plate) as shown in FIG. Heat treatment may be carried out at 200 ℃ to 500 ℃.

Next, the acid metal leached from the recovered metal powder to obtain a metal ion aqueous solution (S200). The acid solution may be a nitric acid solution, hydrochloric acid solution, sulfuric acid solution and the like. The reducing agent may use hydrogen peroxide, in addition to H ₂ , H ₂ S, NH ₃ , N ₂ H ₄ It may be used. The reducing agent rapidly increases the dissolution rate of the metal by acid during leaching. The order of mixing the sample, acid solution and reducing agent can vary.

Thereafter, the flame treatment to obtain a primary nanopowder (S300). The flame treatment involves spraying the metal ion aqueous solution into the microdroplets and then passing the flame through the flame. Spraying into the microdroplets may use an ultrasonic atomizer, wherein the droplet size may be about 10 μm, more specifically about 5 μm to 20 μm. The temperature of the flame may be between 800 ° C and 1700 ° C.

The microdroplets move to the flame by a transport gas such as argon and are synthesized into nanopowders. The synthesized nanopowders may be attached by thermophoresis to the surface of the glass tube in front of the flame device and the cooling water flowing therein.

The microdroplet spray, flame treatment and attachment described above may use the apparatus disclosed in the present applicant's Korean application No. 2002-0031167.

The apparatus includes five concentric tubes and can be supplied with microdroplets and transfer gas, inert gas, hydrogen, oxygen and air from the inside. Argon may be used as the carrier gas and the inert gas.

Next, the obtained primary nanopowder is heat treated (S400). The heat treatment may be performed while supplying oxygen or air at 700 ° C. to 1000 ° C., and may be performed for 30 minutes to 2 hours. When the metal powder is a ternary cathode active material, the secondary nanopowder obtained thereby has physical properties that can be used as the cathode active material.

Hereinafter, the present invention will be described in detail through experimental examples. In the experiment, a ternary positive electrode active material having a layered structure including lithium, cobalt, nickel, and manganese is to be recovered, but the present invention is not limited thereto. The specific composition of the ternary catalyst may be LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ .

<Anode Powder Recovery>

In the waste lithium ion battery, the positive electrode active material is fixed in a powder form using an organic binder on aluminum foil, which is a positive electrode. The positive electrode plate on which the positive electrode active material is fixed is crushed (cut) and pulverized, and then heat-treated in an electric furnace at 300 ° C. to remove the binder. After that, using a grinder equipped with two rotary blades, the positive electrode plate and the positive electrode active material were separated into pieces by particle size separation.

The results of analyzing the components of the separated cathode active material are shown in Table 1. The analysis was performed using an atomic absorption spectrometer (Analyst440, PerkinElmer) after the sample was dissolved in aqua regia.

Table 1.

Co Li Ni Fe Mn Cu Al Ca balance % 19.8 7.3 19.9 0 18.3 0 0 0.008 34.7

As can be seen in Table 1, the valuable metals were made of Co, Li, Ni, and Mn, and the component contents were 19.8% Co, 7.3% Li, 19.9% Ni, and 18.3% Mn. The molar ratio of Li: Co: Ni: Mn was 1: 0.33: 0.33: 0.33.

The chemical crystal structure of the recovered ternary cathode active material was analyzed using XRD. The results are shown in FIG. 3, and XRD patterns with LiCoO ₂ reagents for comparative analysis showed that the crystalline form of the recovered ternary positive electrode active material was the same as that of the reagent grade LiCoO ₂ .

<Nitrate reduction leaching>

The obtained cathode active material powder was dissolved using nitric acid and hydrogen peroxide to obtain a metal ion aqueous solution (metal nitrate mixed solution).

The experimental apparatus used is shown in FIG. Reduction of leaching was carried out in a 100 ml water jacketed Pyrex reactor. A condenser was installed on top of the reactor to prevent evaporation of the solution and stirred with a magnetic bar.

The leaching solution and the positive electrode active material powder were stirred while heating to a solid solution ratio of 1:10. Thereafter, while the solution was heated, a certain amount of hydrogen peroxide was introduced through a Teflon tube. Unlike the experiments, nitric acid solution may be added after mixing hydrogen peroxide and the positive electrode active material powder.

The results of the leaching reduction experiments conducted for 2 hours in nitric acid, 10 vol.% H ₂ O ₂ , 60 ° C., 200 rpm, and 1 hour are shown in Table 2.

Table 2

Co Ni Li Mn mg / L 9100 9200 5000 9300 mol / L 1.0 1.0 4.7 1.1

<Preparation of primary nanopowder using flame spraying>

After spraying the metal nitrate mixed solution into the fine droplet of about 10㎛ using the ultrasonic spray device, argon gas, which is a carrier gas, was injected into the flame through the center of the flamethrower. In order to maintain a constant spray volume, the injection pump was used to maintain a constant volume of the spray solution in the spray apparatus. The flow rates from the inner core were 1 liter / min of argon feed gas, 1 liter / min of argon gas, 5 liter / min of hydrogen, 6 liter / min of oxygen, and 15 liter / min of air. The flame temperature was about 1200 ° C.

The nanopowder formed by the flame was recovered by thermophoresis in a glass tube whose surface was cooled.

FIG. 5 is a transmission electron microscope photograph of LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ (the ratio of Co, Ni, and Mn may be changed) prepared by flame spraying from a nitric acid leachate. From the transmission electron micrograph, the average particle diameter was about 10 nm, and it was confirmed that the particle size was uniform.

<Heat treatment>

The nanopowder was placed inside a tubular electric furnace preheated to 800 ^° C. and heat-treated for 1 hour while introducing air at a flow rate of 1 liter / min. The heat treatment improves the crystallinity of the nanopowder.

6 shows the XRD results of the nanopowder before and after the heat treatment. Compared to before heat treatment, the XRD strength of the powder after heat treatment was significantly increased. It was confirmed that the LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ powder having a layered structure was prepared and the same as the XRD pattern of LiCoO ₂ , which is a commercial powder of FIG. 4. It can be used as a ternary cathode active material.

Having described the specific part of the present invention in detail, it will be apparent to those skilled in the art that such a specific description is merely a preferred embodiment, thereby not limiting the scope of the present invention. something to do. Thus, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

       1 is a process chart showing a method for manufacturing nano-powder from the waste lithium ion battery according to the present invention,

       2 is a photograph of a ternary positive electrode active material fixed to a positive electrode plate,

3 is an XRD analysis result of LiCoO ₂ reagent and recovered tertiary cathode active material,

       4 is a view showing a device used for leaching reduction,

       5 is a transmission electron micrograph of the nanopowder obtained through the flame spraying process,

       6 shows XRD analysis results of nanopowders before and after heat treatment.

Claims (10)

Separating and obtaining a metal component from a waste lithium ion battery; Acid leaching the metal component in a reducing component atmosphere to obtain a metal ion aqueous solution; Spraying the aqueous metal ion solution into microdroplets; Passing the microdroplets through the flame to obtain nanopowders comprising the steps of obtaining nanopowders from the waste lithium ion battery. The method of claim 1, The metal component is a nano-powder manufacturing method from a waste lithium ion battery, characterized in that obtained from a cathode active material. The method of claim 2, The nano-powder manufacturing method from the waste lithium ion battery, characterized in that it further comprises the step of heat-treating the nano-powder. The method of claim 3, wherein The heat treatment is a nano-powder manufacturing method from the waste lithium ion battery, characterized in that is carried out while supplying oxygen at 700 ℃ to 1000 ℃. The method of claim 2, The nano-powder is a nano-powder manufacturing method from the waste lithium ion battery, characterized in that the ternary cathode active material containing lithium, cobalt, nickel and manganese. The method of claim 2, Obtaining the positive electrode active material component, Primary grinding of the positive electrode plate to which the positive electrode active material is fixed using an organic binder; Heat-treating the pulverized positive electrode plate and the positive electrode active material to remove the organic binder; And Secondary grinding after heat treatment, the method for producing a nano-powder from the waste lithium ion battery comprising the step of separating the positive electrode plate and the positive electrode active material. The method of claim 2, The flame generating device comprises five concentric tubes, A method for producing nanopowder from a waste lithium ion battery, characterized in that the feed gas and the fine droplets, inert gas, hydrogen, oxygen, air are supplied from a central tube in this order. The method of claim 2, The acid leaching is nitric acid, the reduction is hydrogen peroxide, characterized in that the nano-powder manufacturing method from a lithium ion battery. Obtaining a ternary positive electrode active material from a waste lithium ion battery; Acid leaching the ternary cathode active material in a reducing component atmosphere to obtain a metal ion aqueous solution; Preparing a nanopowder by spraying the aqueous metal ion solution using ultrasonic waves and then performing flame treatment; And Method of producing a nanopowder from a waste lithium ion battery comprising the step of heat-treating the nanopowder at 700 ℃ to 1000 ℃. 10. The method of claim 9, The ternary cathode active material is LiCo _1/3 Ni _1/3 Mn _1/3 O _{2 The} method for producing nano-powder from the waste lithium ion battery, characterized in that.

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