KR20210077962A - Method for recovering valuable metals from used battery cell - Google Patents

Abstract

The present invention relates to a method for recovering valuable metals from a battery cell, and more specifically, to a method for recovering valuable metals from a battery cell, which minimizes powder loss by optimizing milling and heat treatment conditions and improves process efficiency by shortening processing time.

Description

Method for recovering valuable metals from battery cells {METHOD FOR RECOVERING VALUABLE METALS FROM USED BATTERY CELL}

The present invention relates to a method for recovering valuable metals from battery cells, and more particularly, to minimize powder loss by optimizing milling and heat treatment conditions, and to shorten processing time to increase process efficiency by optimizing valuable metals from battery cells. It's about how to get it back.

Lithium rechargeable batteries have high capacity and high output compared to other secondary batteries such as nickel-cadmium (Ni-Cd), nickel-metal hydride (Ni-MH), and silver-zinc (Ag-Zn) batteries. Because of its excellent performance and relative superiority in weight and volume of batteries, its use as an energy source for portable electronic devices such as notebook PCs, mobile phones, cameras, and MP3 players is gradually expanding, and in the future, portable information and communication technologies As the demand for devices is expected to continue to increase, the demand for lithium secondary batteries is also expected to continue to expand.

In addition, with the trend of strengthening environmental regulations such as continuous high oil prices, reduction of carbon dioxide emissions according to the climate change agreement, and the expansion of clean energy supply, explosive new demand is created in new application fields such as hybrid vehicles, robots, and energy storage. Therefore, lithium secondary battery manufacturers continue to increase the production of batteries by expanding production facilities. In addition, the increase in production due to the expansion of production facilities for lithium secondary batteries inevitably leads to an increase in the amount of defective products in the manufacturing process.

On the other hand, a lithium secondary battery consists of a positive electrode plate, a negative electrode plate, an electrolyte, and a separator, among which the positive electrode plate consists of an active cathodic material, a conductor, a binder, and a current collector, and is the most widely used material as a positive electrode active material. is lithium cobalt oxide (LiCoO2). Recently, in the case of lithium ion polymer batteries, a part of cobalt has been replaced with manganese (Mn) or nickel (Ni), and 3 such as _{Li(Ni x} Co _y Mn _z O _{2 )} The amount of the positive electrode active material used is also gradually increasing.

A large amount of cobalt is contained in the positive electrode scrap generated in the manufacturing process of lithium secondary batteries, and its recycling is attracting great attention in terms of securing resources of rare metals as well as high added value of cobalt.

As a method for recovering cobalt from positive electrode scrap, a method is mainly used to extract cobalt alloy using a high-temperature melting furnace, then refining it using wet separation and refining technology, and then recovering it as a cobalt compound or lithium cobalt oxide. However, the pyrometallurgical process of extracting cobalt into an alloy using a high-temperature melting furnace is a process that is not easy to adopt by small and medium-sized recycling companies because the facility investment cost is very high.

In addition, when the positive electrode plate is melted using the dry smelting process, it is difficult to simultaneously recover lithium, a component of the positive electrode active material, and aluminum (Al), a material of the current collector. Therefore, it is preferable to extract cobalt and lithium using a wet recovery technique using an acid or alkali, and then separate and purify it to recover a high-purity compound or a precursor of a positive electrode active material.

However, in the dry smelting process and wet recovery technology, the powder loss is large and the working efficiency is lowered by repeatedly separating the powder several times using a particle size separator.

Therefore, it is required to develop a method for recovering valuable metals that can minimize powder loss by simplifying the process and increase process efficiency by shortening the processing time.

Korean Patent Registration No. 10-1618373

The present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to recover valuable metals from a battery cell that simplifies the process step and minimizes powder loss by dividing the positive electrode plate into two parts and pulverizing it and then heat-treating it. to provide a way

A method for recovering a valuable metal from a battery cell according to an embodiment of the present invention comprises the steps of discharging and separating the battery cell; obtaining a positive electrode plate from the separated battery cell; grinding the positive electrode plate; and heat-treating the pulverized positive electrode plate.

In one embodiment, the step of separating the heat-treated positive electrode plate to recover the valuable metal; characterized in that it further comprises.

In one embodiment, the separating step is characterized in that the battery cell is separated into a positive electrode plate, a separator and a negative electrode plate.

In an embodiment, the positive electrode active material of the positive electrode plate is Li _x [Ni _a Co _b Mn _c ]O ₂ (1<x<2, a+b+c=1).

In one embodiment, the pulverizing step comprises pulverizing the positive electrode plate through a ball mill, and the pulverizing time is characterized in that within 25 minutes.

In one embodiment, the pulverizing comprises: cutting the positive electrode plate separated from the battery cell; a first grinding step of grinding the cut positive electrode plate; and a second grinding step of pulverizing the positive electrode plate pulverized by the first pulverizing step.

In one embodiment, in the first grinding step, the ball mill is operated within 5 minutes at a rotation speed of 150 to 250, and in the second crushing step, the ball mill is operated at 450 to 550 rotation speed, for 10 minutes to 20 minutes. characterized in that it works.

In an embodiment, the heat treatment is characterized in that the heat treatment is performed at a temperature of 400° C. to 600° C. for 30 minutes to 1 and a half hours.

According to the present invention, the positive electrode plate is divided into two parts and then heat-treated to simplify the process step and minimize powder loss.

1 is a flowchart of a method for recovering a valuable metal from a battery cell according to an embodiment of the present invention.

The present invention will be described in detail with reference to the accompanying drawings as follows. Here, repeated descriptions and detailed descriptions of well-known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted. The embodiments of the present invention are provided in order to completely explain the present invention to those of ordinary skill in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer description.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, preferred examples are presented to help the understanding of the present invention. However, the following examples are only provided for better understanding of the present invention, and the content of the present invention is not limited by the examples.

< from the battery cell How to recover valuable metals >

1 is a flowchart illustrating a method for recovering valuable metals from a battery cell according to an embodiment of the present invention.

The method for recovering valuable metals from a battery cell includes the steps of discharging and separating the battery cell (S100), obtaining a positive electrode plate from the separated battery cell (S200), crushing the positive electrode plate (S300), the crushed positive electrode It may include the step of heat-treating the electrode plate (S400).

In the step of discharging and separating the battery cell (S100), the battery cell may be separated into a positive electrode plate, a separator, and a negative electrode plate.

In the step (S200) of obtaining a positive electrode plate from the separated battery cell, the positive electrode plate contains a positive electrode active material, and the positive electrode active material is Li _x [Ni _a Co _b Mn _c ]O ₂ (1<x<2, a+b +c = 1). That is, the present invention relates to a method for recovering lithium (Li), nickel (Ni), cobalt (Co) and manganese (Mn) from a positive electrode active material included in a positive electrode plate.

The step of crushing the positive electrode plate (S300) is a step of crushing the positive electrode plate using a ball mill. In one embodiment, the step of crushing the positive electrode plate (S300) includes the step of cutting the positive electrode plate separated from the battery cell (S310), the first crushing step (S320) and the first crushing step of crushing the cut positive electrode plate. may include a second grinding step (S330) of pulverizing the anode plate pulverized by

By pulverizing the positive electrode plate through two processes, the particle size separation operation can be omitted, and thus, the effect of minimizing powder loss can occur.

In the first grinding step, the number of revolutions of the ball mill is 150 to 250, and in the second grinding step, the number of revolutions of the ball mill is 450 to 550. In the pulverizing step (S300), the ball mill progress time is less than 25 minutes in total in the first and second pulverizing steps. In one embodiment, the first grinding step is characterized in that the ball mill progress time is within 5 minutes, the second grinding step is characterized in that 10 minutes to 20 minutes. If the number of revolutions of the ball mill is less than 150, the number of friction between the sample and the ball and the friction force are small, which may cause a problem in that the sample is not pulverized. And, even if the rotation speed of the ball mill exceeds 250 and the sum of the ball mill running times exceeds 25 minutes, the effect increase is insignificant.

The heat treatment of the pulverized positive electrode plate (S400) is characterized in that the heat treatment is performed at a temperature of 400° C. to 600° C. for 30 minutes to 1 and a half hours.

And, the method of recovering the organic metal from the battery cell according to the present invention may further include the step of recovering the valuable metal by sieving the heat-treated positive electrode plate (S500).

If the heat treatment temperature is less than 400 ° C and the duration is less than 30 minutes, the yield of valuable metals recovered by sieving is reduced, and when the heat treatment temperature is more than 600 ° C and the heat treatment proceeding time exceeds 1 hour and a half, the effect increases no it is inefficient

< Experimental example 1>

After dismantling the waste lithium secondary battery cell to obtain a positive electrode plate, the positive electrode plate was cut to 1 cmX1 cm, and 50 g of a negative electrode sample and 200 g of a 10 mm diameter zirconia ball were put into 500 ml of a planetray mono mill (FRITSCH). Grinding was carried out for 20 minutes.

Condition first crush second crush total time Powder yield (%) Example 1 hours (minutes) 0 20 20 85.23 number of revolutions 200 500 Example 2 hours (minutes) 5 15 20 98.15 number of revolutions 200 500 Example 3 hours (minutes) 10 10 20 94.08 number of revolutions 200 500 Example 4 hours (minutes) 15 5 20 90.76 number of revolutions 200 500

In the first grinding step, the number of revolutions of the ball mill was set to 200, and the second grinding step was set to 500. And, Experimental Example 1 shows the powder yield according to the change in the operation time of the ball mill in the grinding process under the same conditions. Referring to Table 1, in the first grinding step, when the sample is pulverized in a ball mill for 5 minutes, and in the second pulverizing step, when the sample is pulverized in a ball mill for 15 minutes, it can be seen that the powder yield is the highest.

< Experimental example 2>

In Experimental Example 1, the powder of Experimental Example 2 having the highest powder yield was heat-treated to measure the powder yield. At this time, the heat treatment conditions were 400° C. to 700° C., and the powder yield was measured by increasing the heat treatment temperature by 100° C. for each sample starting at 400° C. The heat treatment time was fixed to 1 hour, and the powder was obtained by performing once by 80 mesh sieve separation.

Temperature (℃) time (hr) Sieve separation (recovery) Powder yield (%) Example 5 400 One One 38.58 Example 6 500 One One 39.23 Example 7 600 One One 41.67 Example 8 700 One One 40.07

Referring to Table 2, it can be seen that the powder yield increases as the heat treatment temperature increases. And, when the heat treatment temperature exceeds 600 ℃, it can be seen that the effect is insufficient because the powder yield is not increased.

Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that it can be done.

Claims (8)

discharging and separating the battery cells;
obtaining a positive electrode plate from the separated battery cell;
grinding the positive electrode plate; and
Including; heat-treating the pulverized positive electrode plate;
A method for recovering valuable metals from battery cells.
According to claim 1,
Recovering the valuable metal by sieving the heat-treated positive electrode plate; Method for recovering valuable metal from a battery cell, characterized in that it further comprises.
According to claim 1,
The separating step is
A method for recovering valuable metals from a battery cell, characterized in that the battery cell is separated into a positive electrode plate, a separator and a negative electrode plate.
According to claim 1,
The positive electrode active material of the positive electrode plate is Li _x [Ni _a Co _b Mn _c ]O ₂ (1<x<2, a+b+c=1) A method of recovering a valuable metal from a battery cell, characterized in that.
According to claim 1,
The crushing step is
A method for recovering valuable metals from a battery cell, characterized in that the anode plate is pulverized through a ball mill, and the pulverization time is within 25 minutes.
6. The method of claim 5,
The crushing step is
cutting the positive electrode plate separated from the battery cell;
a first grinding step of grinding the cut positive electrode plate; and
A method for recovering valuable metals from a battery cell, comprising: a second crushing step of crushing the positive electrode plate pulverized by the first crushing step.
7. The method of claim 6,
In the first grinding step, the ball mill is operated within 5 minutes at a rotation speed of 150 to 250, and in the second crushing step, the ball mill is operated at 450 to 550 rotation speed, for 10 minutes to 20 minutes. A method for recovering valuable metals from battery cells.
According to claim 1,
The heat treatment step is
A method for recovering valuable metals from battery cells, characterized in that heat treatment is performed at a temperature of 400° C. to 600° C. for 30 minutes to 1 hour and a half.

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