KR101965415B1 - Secondary battery plate drying method using multiple chambers having stepwise pressure and differential heat transfer atmosphere - Google Patents

Abstract

The present invention relates to a method for drying an electrode plate for a secondary battery. According to the present invention, the method comprises the steps of: providing a plurality of drying chambers and cooling chambers in which an inlet and an outlet are formed and sequentially connected; sequentially injecting an electrode plate into the drying chambers in which an internal pressure is gradually lowered; and forming and drying different heat transfer atmospheres around the electrode plate injected into the drying chambers by driving a heat transfer means differently installed inside each of the drying chambers formed with different internal pressures. According to the present invention, a surface texture of the electrode plate can be prevented from being weakened or damaged due to a rapid change in pressure inside a chamber by sequentially injecting the electrode plate into the chamber formed with an internal pressure. Also, different heat transfer atmospheres are formed in accordance with the internal pressure of the chamber to perform an effective heat transfer to the electrode plate, thereby rapidly drying the electrode plate.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of drying a plate for a secondary battery using multiple chambers in which a stepwise pressure and a different heat transfer atmosphere are formed,

The present invention relates to a method of drying a binder or a solvent applied to an electrode plate during a series of processes for manufacturing a negative electrode and a positive electrode for a secondary battery, and more particularly, to a method of drying a binder or a solvent applied to a plurality of chambers To a drying method of an electrode plate for a secondary battery, which dries the electrode plate sequentially by drying.

Generally, the secondary battery is charged and discharged by the oxidation and reduction reaction of the positive electrode plate and the negative electrode plate, and the quality of the battery is changed according to the drying condition at the time of manufacturing the electrode plate. When the negative electrode or the positive electrode plate contains moisture, impurities such as oil and gas, the action of the polarity becomes irregular or poor, and the rated energy is not generated, and the life of the battery is remarkably reduced.

In order to solve this problem, an electrode plate was put into a sealable chamber from the outside, and after the chamber was changed to a vacuum state, the air flow was heated by a built-in heater and dried by circulating hot air. Therefore, it is possible to improve the overall quality by eliminating the oxygen contained in the air stream in the vacuum process and preventing the oxidation, as well as drying out the impurities of the electrode plate together with the foreign substances contained in the air stream.

Korean Patent No. 10-1175032 "Plate drying apparatus" and No. 10-1193169 "Plate drying apparatus and method" In the proposed invention, it is possible to improve the overall quality and composition of the electrode plate by supplying inert gas for forming the air flow in the process of vacuum drying the electrode plate, preventing oxidation of the electrode plate, and removing heat and smooth water.

However, since the inert gas is merely supplied to the inside of the vacuum state in the weak vacuum state, the radiant heat and the conduction heat are weak from the heater, so that the time and energy consumed for drying are inevitably increased.

In order to solve such a problem, the inventor of the present invention developed a "method for drying a polar plate for a secondary battery" of the Japanese Patent No. 10-1800715 as a prior invention. In this invention, a heater is operated in a pressurized pressure atmosphere formed by injecting a catalyst into a chamber There is disclosed a method of drying an electrode plate by drying the electrode plate with a heated air flow and then forming a vacuum atmosphere inside the chamber to dry the electrode plate for discharging the impurities to the outside.

However, in the prior art, a vacuum-pressurizing-vacuum atmosphere is formed inside the chamber after the electrode plate is put into the chamber, and the pressure deviation acting on the electrode plate between each process is large, There is a problem that the drying speed is lowered as the air flow is heated only in the pressurized atmosphere inside the chamber.

Korean Patent Registration No. 10-1175032 (entitled "Plate Drying Apparatus") Korean Registered Patent No. 10-1193169 (entitled "Plate Drying Apparatus and Method") Korean Patent Registration No. 10-1800715 (entitled "Method for Drying Plate for Secondary Battery)

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a method and apparatus for drying an electrode plate, And a drying method of the electrode plate for a secondary battery that can dry quickly.

In order to accomplish the above object, the present invention provides a method of sequentially transferring and drying an electrode plate for a secondary battery in a plurality of chambers, comprising: providing a plurality of drying chambers and a cooling chamber sequentially formed with an inlet and an outlet, And sequentially driving the plurality of drying chambers in which the pressure is gradually lowered, and driving heat transfer means provided inside the plurality of the plurality of drying chambers having different internal pressures, Thereby forming a heat transfer atmosphere and drying the electrode plate.

According to the present invention, the electrode plate is dried in a transforming drying chamber in which the internal pressure is gradually lowered from a predetermined pressure to a minimum pressure, and then sequentially injected into the atmospheric pressure drying chamber in which the internal pressure is maintained at the minimum pressure.

According to the present invention, the internal pressure of the transforming drying chamber is gradually lowered to vacuum pressure at 550 to 700 Torr.

According to the present invention, the internal pressure of the transforming and drying chamber is maintained at 550 to 700 Torr for 100 to 150 minutes, and then reduced at a rate of 30 to 70 Torr / min.

According to the present invention, the dry-heated electrode plate is cooled by injecting it into a transforming cooling chamber which is step-wise boosted at a rate of 30 to 70 Torr / min at a vacuum pressure of 550 to 700 Torr with an internal pressure.

According to the present invention, the heat transfer means is a heater which is installed inside the drying chamber differently from each other.

According to the present invention, the heater installed in the transforming and drying chamber has a larger installation area than the heater installed in the atmospheric-pressure drying chamber.

According to the present invention, the heater of the transforming and drying chamber is installed on both sides of the inside of the chamber, and the heater of the drying chamber is installed on the upper, lower and both sides of the chamber so as to surround the plate.

According to the present invention, the heat transfer means of the transforming and drying chamber further includes a blowing fan for circulating the airflow inside the chamber.

According to the present invention, the inside of the transforming and drying chamber is heated at a rate of 0.2 to 2 ° C / min at a temperature of 5 to 10 ° C and heated to 100 to 150 ° C, min and heated to 130 to 180 ° C.

According to the present invention, the inside of the cooling and drying chamber is cooled at a temperature of 130 to 180 ° C at a rate of 0.2 to 2 ° C / min and cooled to 35 to 65 ° C.

According to the present invention, it is possible to prevent weakening or damage of the surface structure of the electrode plate due to a sudden change in pressure inside the chamber by sequentially introducing the electrode plate into the chamber in which the internal pressure is formed step by step, The heat transfer is efficiently performed to the electrode plate, and the electrode plate can be dried quickly.

1 is a flow chart showing a drying method according to the present invention.
2 is a configuration diagram of a drying apparatus for carrying out the drying method according to the present invention.
Fig. 3 is a configuration diagram of the variable pressure drying chamber in Fig.
FIG. 4 is a configuration diagram of the atmospheric-pressure drying chamber in FIG.
Fig. 5 is a configuration diagram of the transforming cooling chamber in Fig. 2. Fig.
6A to 6C are schematic diagrams illustrating the drying process of the apparatus of FIG. 2;

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

In the following description of the embodiment, when it is determined that technical characteristics of the present invention may be unnecessarily obscured by those skilled in the art such as well-known functions and configurations well known in the art, It will be omitted.

The present invention relates to a method of drying a binder or a solvent applied to an electrode plate during a series of processes for manufacturing a negative electrode and a positive electrode for a secondary battery, and it is an object of the present invention to improve the quality of a dried electrode plate through steps S10 to S40, This is a drying method for an electrode plate for a secondary battery that can be improved.

In order to implement the drying method of the present invention, the drying apparatus 100 for a secondary battery electrode plate as shown in FIG. 2 may be used. The drying apparatus 100 includes a plurality of chambers 10, 20, and 30 in which a largely dried plate is sequentially taken in and out. The plurality of chambers 10, 20, and 30 are formed in a tunnel shape having an inlet and an outlet so that the electrode plate 1 can flow in and out, and gate valves 11, 21, and 31 are provided at the inlet and the outlet, respectively The chambers 10, 20 and 30 are opened and closed. 2, the variable pressure drying chamber 10, the atmospheric pressure drying chamber 20, and the variable pressure cooling chamber 30 are sequentially arranged in a plurality of chambers 10, 20, and 30 . The plurality of chambers 10, 20 and 30 having different internal pressures are formed differently in the heat transfer atmosphere for drying the electrode plates, which will be described later. On the other hand, in the variable pressure drying chamber 10 and the variable pressure cooling chamber 30, there are formed injection passages 12 and 32 and exhaust passages 13 and 33 for introducing and discharging external air or gas into the interior, 20 are provided with an exhaust flow path 23. In FIG. 2, the number of the chambers 10, 20 and 30 is three. However, the number of the chambers is not limited to three, and the number of the drying chambers may be three or more.

According to the present invention, the electrode plate (1) is heated and dried through sequentially connected transforming and drying chamber (10) and atmospheric pressure drying chamber (20), then cooled through a transforming cooling chamber (30) to complete drying. The transforming drying chamber 10, the atmospheric pressure drying chamber 20 and the transforming cooling chamber 30 in which the electrode plates 1 are sequentially transferred are arranged such that heat transfer means provided therein for heating and cooling the inner plate 1 and the inner plate 1 Which will be described later. The plurality of chambers 10, 20, and 30 are connected by the transfer unit 40 so that the electrode plate drying process is sequentially performed.

The transfer unit 40 includes a rail 41 connected to the chambers 10, 20 and 30 for guiding the entry and exit of the electrode plate 1 into and out of the chambers 10, 20 and 30, And a motor 42 for driving the motor. When the heating or cooling process set in each of the chambers 10, 20 and 30 is completed, the electrode plate mounting portion mounted on the plurality of pole plates 1 by the control unit (not shown) And then transferred to the next chamber.

3 to 5, the heat transfer means 50 is installed in the chambers 10, 20, and 30 to efficiently dry the polar plate 1 to be transferred. Heaters 51 and 52 provided in the interior of the drying chamber 20 so as to be different from each other, a cooling heat exchanger 53 installed in the variable pressure cooling chamber 30 for cooling the air flow, a variable pressure drying chamber 10, And air blowing fans 54 and 55 which are installed on the upper side of the inside of the air conditioner 30 and circulate the air heated or cooled by the heater 51 or the cooling heat exchanger 53 toward the electrode plate 1. The heaters 51 and 52 are installed differently according to the pressures of the respective drying chambers 10 and 20, and are installed in a larger area as the internal pressures of the drying chambers 10 and 20 decrease. 3 to 5, the heater 51 of the transforming and drying chamber 10 is installed on both sides of the inside of the chamber 10 with the electrode plate 1 interposed therebetween, The heater 52 of the heater 20 is installed on the upper, lower, and both sides of the chamber 20 so as to surround the electrode plate 1 placed inside. Since the variable pressure drying chamber 10 has a high internal pressure and an air flow is easily formed therein, the heaters 51 are installed on both sides of the inside of the chamber 10, and the pressure in the atmospheric pressure drying chamber 20 Are installed on the upper, lower side and both sides of the inside of the chamber 20 so as to surround the electrode plate 1. Since the cooling heat exchanger 53 of the transforming cooling chamber 30 is formed with a constant internal pressure similarly to the transforming drying chamber 10, the airflow can be easily formed in the inside by the blowing fan 55, The unit 53 is installed on both sides of the inside of the cooling chamber 30. [ Therefore, heat transfer is efficiently performed to the electrode plate 1 while reducing energy by forming a differential heat transfer atmosphere in accordance with the pressure formed inside the plurality of chambers 10, 20, 30 in which the electrode plate 1 is heated and cooled, You can dry it.

6A to 6C are schematic views for explaining an electrode plate drying method using the drying apparatus 100 described above, and the electrode plate drying method will be described with reference to the drawings.

First, a drying apparatus 100 is installed, and a plurality of drying chambers 10 and 20 and a cooling chamber 30 are sequentially connected to form an inlet and an outlet, respectively (S10). Next, an electrode plate holder on which a plurality of electrode plates 1 are mounted is placed on the rails 41, and the motors 42 are driven to move sequentially the plurality of drying chambers 10, 20 along the rails 41 The transforming drying chamber 10 is filled with external air or an inert gas such as argon or nitrogen through the injection path 12 to form a predetermined internal pressure and then the electrode plate 1 is placed in the transforming drying chamber 10). In order to rapidly dry the electrode plate 1 having a high content of impurities, the transforming drying chamber 10 is initially formed with a relatively high internal pressure of 550 to 700 Torr, And the gas inside the chamber 10 is discharged through the pressure reducing unit 10 in a stepwise manner. At this time, it is preferable to maintain the initial internal pressure of the transforming drying chamber 10 at 550 to 700 Torr for 100 to 150 minutes, then reduce pressure at a rate of 30 to 70 Torr / min to form a vacuum pressure of 70 Torr / min (1), the surface texture of the dried plate (1) may be weakened. When the pressure is reduced to less than 30 Torr / min, there is a problem that the drying process is delayed.

The polar plate 1 primarily dried in the variable pressure drying chamber 10 is transferred to the atmospheric pressure drying chamber 20 and dried secondarily. The atmospheric pressure drying chamber 20 has a minimum pressure value The primary dried electrode plate 1 is transferred and reheated while the internal pressure is maintained at the same pressure value. At this time, it is preferable that the internal pressure of the atmospheric-pressure drying chamber 20 is a vacuum pressure (approximately 1 to 10 ^-3 Torr) to completely remove impurities therein. It is preferable that the drying times of the variable pressure drying chamber 10 and the atmospheric pressure drying chamber 20 are the same for the sequential drying process of the multiple plate 10. For example, in the variable pressure drying chamber 10 and the atmospheric pressure drying chamber 20) can be performed in 2 to 4 hours. By forming the inner pressure of the plurality of drying chambers 10, 20 in which the electrode plates 10 are sequentially introduced in a stepwise manner, a sudden change in pressure does not act on the electrode plate 1 and the electrode plate 1 is dried can do.

Subsequently, the transforming drying chamber 10 in which the electrode plate 1 is inserted and the internal pressures are made different from each other, and the heat transfer means 50 provided in the inside of the atmospheric drying chamber 20 are driven to separate the drying chambers 10, A different heat transfer atmosphere is formed around the inserted electrode plate 1 and dried (S30). As described above, as the heat transfer means, the heaters 51 and 52 installed in different areas according to the internal pressures of the drying chambers 10 and 20 and the blowing fans 54 and 55 installed in the chambers 10 and 20 are driven Thereby forming different heat transfer environments in the chambers 10 and 20 and drying them. That is, the target pressure is set to 550 to 700 Torr, which is set by injecting outside air or gas into the inside of the transforming drying chamber 10. After the electrode plate 1 is transferred to close the gate valve 11, The heater 51 installed on both inner sides of the electrode plate 1 is heated and the blowing fan 54 on the upper side is driven to form a heating air flow upward through both sides of the electrode plate 1 to dry the electrode plate 1. [ The inside of the transforming drying chamber 10 during heating is preferably heated to 100 to 150 ° C at 5 to 10 ° C and is heated at a rate of 0.2 to 2 ° C / min to prevent rapid heating and thermal deformation of the electrode plate 1 . When the primary drying is completed in the variable pressure drying chamber 10, the electrode plate 1 is transferred to the inside of the atmospheric pressure drying chamber 20 adjacent thereto. The atmospheric pressure drying chamber 20 is formed at a minimum pressure, preferably a vacuum pressure, of the transforming drying chamber 10. When the heater 53 installed at the upper, lower and both sides inside the chamber 20 is heated, 52 are effectively secondarily dried by covering the electrode plate 1 with the radiant heat. At this time, it is preferable that the atmospheric pressure drying chamber 20 is heated at a rate of 0.05 to 0.4 ° C / min at a final atmospheric temperature of 100 to 150 ° C of the transforming and drying chamber 20 and heated to 130 to 180 ° C. The electrode plate 1 is more completely dried in the state where the impurities are removed. By forming a differential heat transfer atmosphere according to the pressure inside the plurality of drying chambers 10 and 20 in which the electrode plate 1 is dried, energy can be saved while efficiently using the heat transfer to the electrode plate 1, .

The electrode plate 1 having passed through the drying chambers 10 and 20 in this manner is charged into the transforming cooling chamber 30 and cooled (S40). When the electrode plate 1 is transferred to the transforming cooling chamber 30, external air or gas is injected into the chamber 30 so as to step up internal pressure. The internal pressure of the chamber 30 is controlled by the pressure in the atmospheric pressure vacuum chamber 20, And the pressure is increased stepwise at a rate of 30 to 70 Torr / min at a vacuum pressure of 550 to 700 Torr. Then, after the gate valve 31 is closed, the cooling water or the coolant is circulated to the cooling heat exchanger 53 provided on both sides of the chamber 30, and the upper blowing fan 55 is driven, A cooling air flow is formed upwardly to cool the electrode plate 1. At this time, the transforming cooling chamber 30 is cooled to 35 to 65 ° C. at 130 to 180 ° C., which is the final atmospheric temperature of the atmospheric drying chamber 20, to prevent thermal shock of the plate 1, The chamber 30 is desirably heated at a rate of 0.2 to 2 占 폚 / min. Through this cooling step, the drying of the electrode plate 1 is completed.

According to the present invention, it is possible to prevent weakening or damage of the surface structure of the electrode plate due to a sudden change in pressure inside the chamber by sequentially introducing the electrode plate into the chamber in which the internal pressure is formed step by step, The heat transfer is efficiently performed to the electrode plate, and the electrode plate can be dried quickly. In addition, since a plurality of electrode plates are successively transferred to a plurality of connected chambers and continuously dried, a continuous drying process is performed without the atmosphere of the electrode plate.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined by the appended claims. It is therefore intended that such variations and modifications fall within the scope of the appended claims.

10: Transformer drying chamber 11, 21, 31: Gate valve
12, 22: Injection flow path 13, 23, 33:
20: atmospheric pressure drying chamber 30: transforming cooling chamber
40: feed section 41: rail
42: motor 50: heat transfer means
51, 52: Heater 53: Cooling heat exchanger
54,55: blowing fan
S10: Step of preparing a plurality of sequentially connected drying chambers
S20: Step of sequentially putting the electrode plate into a plurality of drying chambers whose internal pressure is gradually lowered
S30: a step of driving different heat transfer means inside each of the drying chambers to form different heat transfer environments around the electrode plates and drying
S40: Step of cooling the electrode plate into the transformer cooling chamber

Claims (11)

A method of sequentially transferring and drying an electrode plate for a secondary battery,
Providing a variable pressure drying chamber, an atmospheric pressure drying chamber, and a cooling chamber, the inlet and the outlet being sequentially connected to each other;
A step of putting an electrode plate into the transforming and drying chamber to maintain the internal pressure at 550 to 700 Torr for 100 to 150 minutes, and then drying under reduced pressure at a vacuum pressure of 30 to 70 Torr / min;
Drying the electrode plate in the transforming and drying chamber to the atmospheric pressure drying chamber to maintain the vacuum pressure and drying the electrode plate; And
And driving the heat transfer means provided in the variable pressure drying chamber and the atmospheric pressure drying chamber, respectively, to form different heat transfer environments,
The inside of the transforming and drying chamber is heated at a rate of 0.2 to 2 ° C / min at a temperature of 5 to 10 ° C at a temperature of 100 to 150 ° C by a heater installed on both sides of the inside of the chamber of the transforming and drying chamber and a blowing fan for circulating the heated airflow The inside of the atmospheric pressure drying chamber is heated at a temperature of 100 to 150 ° C at a rate of 0.05 to 0.4 ° C / min by heating the top, bottom, and both sides of the inside of the atmospheric pressure drying chamber so as to surround the electrode plate, And heating the mixture to 130 to 180 캜. delete delete delete The method according to claim 1,
Wherein the dried and heated plate is cooled in a transforming cooling chamber which is stepped up at a rate of 30 to 70 Torr / min at a pressure of 550 to 700 Torr at a vacuum of an internal pressure, thereby cooling the electrode plate. delete delete delete delete delete 6. The method of claim 5,
Wherein the inside of the transforming cooling chamber is cooled at a temperature of from 130 to 180 DEG C at a rate of from 0.2 to 2 DEG C / min and cooled to a temperature of from 35 to 65 DEG C.

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