KR102382880B1 - Dissolution apparatus of lithium salt powder for preparing electrolyte - Google Patents

Abstract

The present invention relates to an apparatus for dissolving lithium salt powder used to prepare an electrolyte solution for a lithium ion battery. and a dissolution chamber for forcibly mixing and dissolving the electrolyte solution and lithium salt powder is disposed between the reactor and the powder container, and the lithium salt powder from the powder container to the dissolution chamber by the negative pressure generated by the dissolution chamber It is configured to flow in, and it relates to a dissolution device for lithium salt powder that can efficiently manufacture high-quality electrolyte in a safer working environment.

Description

Dissolution apparatus of lithium salt powder for preparing electrolyte

The present invention relates to an apparatus for dissolving lithium salt powder used to prepare an electrolyte solution for a lithium ion battery. and a dissolution chamber for forcibly mixing and dissolving the electrolyte solution and lithium salt powder is disposed between the reactor and the powder container, and the lithium salt powder from the powder container to the dissolution chamber by the negative pressure generated by the dissolution chamber It is configured to flow in, and it relates to a dissolution device for lithium salt powder that can efficiently manufacture high-quality electrolyte in a safer working environment.

Lithium ion batteries, which are increasingly in demand in recent years, include a positive electrode and a negative electrode, a separator, and an electrolyte, and the electrolyte is usually composed of a solution in which lithium salt and other additives are dissolved in an electrolyte solvent consisting of an organic carbonate compound.

The lithium salt used to prepare the electrolyte is a chemically very unstable compound. For example, lithium hexafluorophosphate (LiPF ₆ ) generates hydrogen fluoride (HF) by reacting with a very small amount of moisture in the air. And the hydrogen fluoride is very toxic to the human body, and has very high corrosiveness and permeability.

Therefore, in the process of producing electrolyte for lithium ion batteries, the electrolyte solution is included in the air in all production processes, from the process of removing moisture from the organic carbonate compound, a raw material, in order to protect manufacturing facilities, equipment and workers, and further improve the quality of the electrolyte. Strict management is required so that it does not come into contact with even the smallest amount of moisture.

In addition, lithium salt generates high heat of reaction and odorous smoke and dust when dissolved in an electrolyte solvent, so it must be handled in a well-ventilated place to protect workers. After dismantling the lithium salt powder container in the reactor, care must be taken not to expose the residue of the lithium salt powder to the atmosphere.

In general, a conventional electrolytic solution manufacturing apparatus uses a powder dissolving device in which a hopper containing lithium salt powder, that is, a powder container, is combined in a vertical structure in a reactor in which an electrolyte solvent is stored. So, the lithium salt powder is introduced into the reactor by free fall from the powder container, and the agitator is rotated in the reactor to cause the dissolution reaction. In addition, the reactor is equipped with a cooling jacket for supplying cooling water, a measuring sensor for measuring the level and weight of the reactant, and an arm hood for absorbing odorous smoke and dust generated during the dissolution process, etc. are installed. there is.

For example, in Patent Publication Nos. 10-2018-80016 (2018.07.11.), 10-2015-29300 (2015.03.18.) and 10-2001-22018 (2001.03.15.) Powder dissolving devices that can be used for manufacturing purposes are introduced. However, in this conventional powder dissolving device, the powder container in which the lithium salt is stored is installed directly on the top of the reactor. A structure that can stand on the floor and a hoist for transporting the powder container should be installed.

In addition, in order to remove the smoke and dust generated in the reactor, since the arm hood must be installed in a position close to the powder container, there is a fear that the arm hood may interfere with the transfer operation of the powder container when transporting the powder container with a hoist, and further If the joint between the powder container and the reactor is not completely sealed or residues remain, the lithium salt may come in contact with moisture in the atmosphere to generate toxic hydrogen fluoride, which may cause serious problems in the safety of workers.

Publication No. 10-2018-0080016 (2018.07.11.), Publication No. 10-2015-0029300 (2015.03.18.) Patent Publication No. 10-2001-0022018 (2001.03.15.)

Accordingly, an object of the present invention is to separate the reactor for storing the electrolyte solution and the powder container for storing the lithium salt powder in a spaced apart state from each other, and use the dissolution chamber disposed therebetween to obtain an electrolyte solution and a completely sealed system in one system. By forcibly mixing and dissolving lithium salt powder, it is to provide a dissolving device for lithium salt powder that is safe in a working environment and can efficiently produce high-quality electrolyte.

Hereinafter, in the present invention, the term 'electrolyte solution' may mean a state in which lithium salt powder is not yet dissolved in a solvent composed of an organic carbonate compound, and a state in which a predetermined amount of lithium salt powder is dissolved in the solvent may mean

An apparatus for dissolving lithium salt powder for preparing an electrolyte according to the present invention includes: a sealed reactor having an internal space for storing an electrolyte solution for preparing an electrolyte and having a cooling pocket installed on the outer surface of which cooling water circulates; A sealed powder container in which a nitrogen purge tube capable of supplying nitrogen gas to the inside is installed as a place to store lithium salt powder at a location spaced apart from the reactor; a dissolution chamber disposed at the lower end of the powder container and forcibly mixing and dissolving the electrolyte solution supplied from the reactor and the lithium salt powder supplied from the powder container; a powder supply pipe for supplying lithium salt powder from the powder container to the dissolution chamber; a solution discharge pipe for transferring the electrolyte solution from the lower end of the reactor to the dissolution chamber; A pipe body for transporting an electrolyte solution mixed with lithium salt powder from the dissolution chamber to the upper end of the reactor, the solution transport pipe having a cooling pocket for circulating cooling water on its outer surface; It is characterized in that it comprises a.

In the dissolution chamber, an impeller for forcibly mixing the electrolyte solution and lithium salt powder and forcibly extruding the solution from the solution discharge pipe to the solution conveying pipe, and a driving motor for rotating the impeller are provided, the rotational force of the impeller and the electrolyte solution It is characterized in that it is configured such that the lithium salt powder stored in the powder container is introduced into the dissolution chamber through the powder supply pipe by the negative pressure generated by the driving force.

In addition, between the solution discharge pipe and the solution conveying pipe, a first powder dissolving line comprising a first powder container, a first dissolving chamber, and a first powder supply pipe, a second powder container, a second dissolving chamber, and a second powder supply pipe comprising a second powder supply pipe Two powder melting lines are installed side by side in parallel, characterized in that it is configured to selectively operate any one of the first powder melting line and the second powder melting line.

In the apparatus for dissolving lithium salt powder for preparing an electrolyte solution according to the present invention, the reactor for storing the electrolyte solution and the powder container for storing the lithium salt powder are separated from each other, and the electrolyte solution and the lithium salt powder are forced between them. Since the dissolution chamber for mixing and dissolving in the furnace is arranged, the reactor and the powder container can be arranged in a horizontal structure, and thus facilities and work space can be conveniently and efficiently used.

In addition, since the reactor, the powder container, and the dissolution chamber are operated in a completely sealed system, the first powder dissolving line and the second powder dissolving line can be selectively operated if necessary, so lithium salt powder or electrolyte solution It is possible to prevent the generation of toxic gas or odorous smoke and dust in contact with the air, and thus a safer working environment can be maintained.

In addition, the impeller mounted in the dissolution chamber forcibly mixes and dissolves the electrolyte solution and the lithium salt powder, and the lithium salt stored in the powder container by the negative pressure generated by the rotational force of the impeller and the driving force of the electrolyte solution. Since the powder is introduced into the dissolution chamber, there is an effect of high working efficiency.

Finally, the apparatus for dissolving lithium salt powder according to the present invention blocks the inflow of impurities during the overall electrolyte preparation process and maintains the temperature of the electrolyte solution stored in the reactor at 30° C. or less to produce a high-quality electrolyte. can

1 is an apparatus for dissolving lithium salt powder for preparing an electrolyte according to the present invention;
FIG. 2 is a view showing the main part of FIG. 1 from another angle.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, since the accompanying drawings illustrate preferred embodiments of the present invention, the scope of the present invention is not limited by these embodiments. In addition, even if it is a configuration essential for carrying out the present invention, detailed description of matters introduced in the prior art or that can be easily implemented by a person skilled in the art from the known technology will be omitted.

The apparatus for dissolving lithium salt powder for preparing an electrolyte according to the present invention, as shown in FIGS. 1 and 2, includes a reactor 10, a powder container 20, a dissolution chamber 30, a powder supply pipe 40, and a solution discharge pipe. (50) and is configured to include a solution return pipe (60).

First, the reactor 10 is a sealed reaction vessel, and before the electrolyte preparation process according to the present invention is started, a solvent used for preparing an electrolyte solution, for example, an organic carbonate compound is stored, and when the electrolyte solution manufacturing process proceeds, the solution is added to the solution. It has the function of recovering, storing and circulating the electrolyte solvent in which the lithium salt is dissolved.

A cooling pocket 11 is installed on the outer surface of the reactor 10 , and cooling water for cooling the temperature of the contents stored in the reactor 10 is circulated in the cooling pocket 11 .

The cooling pocket 11 improves the dissolution efficiency by cooling the reaction heat generated during the dissolution reaction of the electrolyte solution and the lithium salt, and furthermore, to prevent deterioration of the quality of the finished electrolyte, maintaining the internal temperature below 30 ° C. desirable. In FIG. 1 , unexplained reference numeral '12' is a 'support' for supporting the reactor 10 .

Next, the powder container 20 is a place for storing lithium salt in a powder state, and has a closed structure to block contact with external air. In the present invention, the powder container 20 is installed at a position spaced apart from the reactor 10, unlike the conventional powder dissolving device, and has a height similar to that of the reactor 10, as well as installed at a lower position than the reactor 10 it might be

The powder container 20 preferably has a hopper shape of upper and lower narrow, and as the lithium salt powder stored in the powder container 20, for example, LiPF ₆ , LiBF ₄ , LiBOB, etc. may be used.

The dissolution chamber 30 is disposed between the reactor 10 and the powder container 20, preferably at the lower end of the powder container 20, and the electrolyte solution supplied from the reactor 10 and the powder container 20 ) to forcibly mix and dissolve the lithium salt powder supplied from

The powder supply pipe 40 is a passage for supplying lithium salt powder from the powder container 20 to the dissolution chamber 30, and is installed between the powder container 20 and the dissolution chamber 30 in the vertical direction. . A control valve (not shown in the drawing) for controlling or blocking the supply of lithium salt powder may be installed in the powder supply pipe 40 .

The solution discharge pipe 50 is a passage for transferring the electrolyte solution from the lower end of the reactor 10 to the dissolution chamber 30 , and the solution return pipe 60 is the reactor 10 from the dissolution chamber 30 . It is a passage that transports the electrolyte solution mixed with lithium salt powder to the top of the A control valve (not shown in the drawing) for controlling or blocking the transfer of the electrolyte solution may be installed in the solution discharge pipe 50 and the solution return pipe 60 , respectively.

In addition, a cooling pocket (not shown) is installed on the outer surface of the solution conveying pipe 60, and the cooling pocket is configured to circulate cooling water, so that the electrolyte solution and lithium passing through the solution conveying pipe 60 are The dissolution efficiency can be improved by cooling the reaction heat generated during the dissolution reaction of the salt.

On the other hand, the dissolution chamber 30, is provided with an impeller (not shown in the drawing) rotated by the driving motor (31). So, the electrolyte solution and the lithium salt powder are forcibly mixed by the rotational force of the impeller, and at the same time, the mixture is forcibly extruded from the solution discharge pipe 50 to the solution conveying pipe 60 .

Therefore, a negative pressure is generated inside the dissolution chamber 30 due to the rotational force of the impeller and the driving force of the electrolyte solution, and the lithium salt powder stored in the powder container 20 by this negative pressure is transferred to the powder supply pipe 40. It is easily introduced into the dissolution chamber 30 through the.

The supply amount of the lithium salt powder flowing into the dissolution chamber 30 through the powder supply pipe 40 may be controlled by the RPM of the impeller. According to an embodiment of the present invention, the rotational speed of the impeller is 2000 ~ 8000rpm, the flow rate of the electrolyte solution passing through the solution conveying pipe 60 may be 1 ~ 2m / s. If the rotation speed of the impeller and the flow rate of the electrolyte solution are too low, a sufficient negative pressure may not be formed inside the dissolution chamber 30, so that the lithium salt powder may not be smoothly sucked.

As the material of the impeller, it is preferable to use a ceramic material that can prevent wear due to friction with the electrolyte solution and lithium salt powder passing through the dissolution chamber 30, or a stainless material such as SUS316L. This is because, when the impeller is worn, the purity of the electrolyte may be lowered, and consequently, the quality of the lithium ion battery may be deteriorated. An impeller meeting the purpose of the present invention can be purchased and used in the market.

In addition, nitrogen purge pipes 21 and 41 for supplying nitrogen gas may be connected to the powder container 20 and the powder supply pipe 40, respectively, and nitrogen supply means are provided at the ends of the nitrogen purge pipes 21 and 41 (not shown in the drawing) is installed. The nitrogen purge pipe 21 installed in the powder container 20 supplies nitrogen gas so that when the lithium salt powder is discharged, a vacuum is not generated inside the powder container 20, and the lithium salt powder is easily discharged, and also After the lithium salt powder is all discharged, the residue remaining inside the powder container 20 is cleanly removed to block adhesion with air.

In addition, the nitrogen purge pipe 41 connected to the powder supply pipe 40 can function to open the powder supply pipe 40 without introducing external air when lithium salt powder is accumulated in the powder supply pipe 40. . In addition, when the powder container 20 is separated or fastened from the powder supply pipe 40 , it may function to prevent the inflow of external air into the dissolution chamber 30 .

According to a preferred embodiment of the present invention, a first powder dissolving line (A) and a second powder dissolving line (B) may be installed side by side in parallel between the solution discharge pipe 50 and the solution return pipe 60 . Here, the first powder dissolving line (A) is composed of a first powder container (20a), a first dissolving chamber (30a) and a first powder supply pipe (40a), the second powder dissolving line (B) is a second It consists of a powder container (20b), a second dissolution chamber (30b), and a second powder supply pipe (40b).

The first powder melting line (A) and the second powder melting line (B) have substantially the same operating structure and function, but are configured to selectively operate any one of them as needed. So, when the first powder melting line (A) is operating, nitrogen purge is performed for the second powder container (20b) and the second powder supply pipe (40b) using the nitrogen purge pipes (21 and 41), and the second powder When the dissolution line (B) is operated, nitrogen purge may be performed for the first powder container (20a) and the first powder supply pipe (40a).

Therefore, it is possible to prevent an unexpected accident in which odorous smoke, dust, or toxic hydrogen fluoride is generated in the process of separating and replacing the powder container 20 in which the lithium salt powder is exhausted, and furthermore, the powder container 20 is replaced It is possible to continue operating the dissolution apparatus of the present invention without waiting time even during the process.

In the dissolution apparatus according to the present invention, only the pure solvent in which the lithium salt is not dissolved is stored in the reactor 10 at the initial stage before the electrolyte preparation process starts, and when the electrolyte preparation process starts, it is stored in the reactor 10 After the solvent is introduced into the dissolution chamber 30 through the solution discharge pipe 50, a certain amount of lithium salt powder is dissolved into the solvent.

Then, the electrolyte solution that has passed through the dissolution chamber 30 is returned to the reactor 10 through the solution conveying pipe 60 in a state in which a small amount of lithium ions are dissolved, and then the electrolyte remaining inside the reactor 10 mixed with the solvent. In this way, as the electrolyte solution circulates through the reactor 10, the solution discharge pipe 50, the dissolution chamber 30, and the solution return pipe 60, the concentration of lithium ions increases little by little, and the lithium ions dissolved in the electrolyte solution When the concentration of is reached a preset value, the electrolytic solution manufacturing process is terminated.

At this time, the concentration of lithium ions dissolved in the electrolyte solution may be measured using a separate measuring device, and through the supply amount of the electrolyte solvent injected into the reactor 10 and the supply amount of lithium salt powder provided in the powder container 20 . can also be calculated. As described above, the dissolution apparatus according to the present invention has the advantage of efficiently manufacturing high-quality electrolyte in a safe working environment.

10; reactor 11; cooling pocket
12; supports 20, 20a, 20b; powder container
21,41; Nitrogen purge tube 30, 30a, 30b; dissolution chamber
31; drive motors 40, 40a, 40b; powder supply pipe
50; solution discharge pipe 60; solution transport pipe
A; first powder melting line B; 2nd powder melting line

Claims (6)

a sealed reactor having an internal space for storing an electrolyte solution for preparing an electrolyte, and having a cooling pocket for circulating cooling water installed on the outer surface;
A place for storing lithium salt powder at a location spaced apart from the reactor, and a sealed powder container in which a nitrogen purge pipe capable of supplying nitrogen gas to the inside is installed;
a dissolution chamber disposed at the lower end of the powder container and forcibly mixing and dissolving the electrolyte solution supplied from the reactor and the lithium salt powder supplied from the powder container;
a powder supply pipe for supplying lithium salt powder from the powder container to the dissolution chamber;
a solution discharge pipe for transferring the electrolyte solution from the lower end of the reactor to the dissolution chamber;
A pipe body for transporting an electrolyte solution mixed with lithium salt powder from the dissolution chamber to the upper end of the reactor, the solution transport pipe having a cooling pocket for circulating cooling water on its outer surface; consists of,
In the dissolution chamber, an impeller for forcibly mixing the electrolyte solution and lithium salt powder and forcibly extruding the solution from the solution discharge pipe to the solution conveying pipe, and a driving motor for rotating the impeller are provided, the rotational force of the impeller and the electrolyte solution The lithium salt powder stored in the powder container is introduced into the dissolution chamber through the powder supply pipe by the negative pressure generated by the driving force,
The supply amount of the lithium salt powder is controlled by the RPM of the impeller mounted in the dissolution chamber, and the electrolyte solution inside the reactor is returned to the reactor through the solution discharge pipe, the dissolution chamber, and the solution return pipe. A dissolving device for lithium salt powder for preparing an electrolyte, characterized in that the concentration of ions is gradually increased.
The apparatus of claim 1, wherein a nitrogen purge pipe capable of supplying nitrogen gas to remove residues of lithium salt powder is connected to the powder supply pipe.
[Claim 3] The method of claim 1 or 2, wherein a first powder dissolving line comprising a first powder container, a first dissolution chamber, and a first powder supply pipe, and a second powder container and a second dissolving pipe are disposed between the solution discharge pipe and the solution conveying pipe. A second powder melting line consisting of a chamber and a second powder supply pipe is installed in parallel, so that any one of the first powder melting line and the second powder melting line can be selectively operated. Lithium salt powder dissolution device for electrolyte production.
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