KR20210052853A - Electrode manufacturing apparatus comprising notching machine configured after cooling machine, and electrode manufacturing method using the same - Google Patents

Abstract

The present invention is an improved process in which a notching process is arranged at the rear part of the process so that the notching quality of a final electrode product can be excellent, and is a novel process that solves a problem of poor punching in the notching process by rapidly cooling a heated current collector using two cooling rolls.

Description

Electrode manufacturing apparatus comprising a notching device disposed after the cooling device, and an electrode manufacturing method using the same.

The present invention relates to an electrode manufacturing apparatus including a notching apparatus disposed after a cooling apparatus, and a manufacturing method of an electrode using the same. Specifically, after the active material is applied to at least one surface of the current collector, and before notching the electrode tab, the current collector to which the active material is applied is heated and dried, cooled again, and then notched, and the electrode manufacturing method using the same. About.

The lithium secondary battery is manufactured by embedding an electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes in a battery case, injecting an electrolyte into the battery case, and impregnating the electrode assembly.

The anode and cathode are manufactured in the following process. First, a current collector of an electrode is provided. The current collector, which is a thin metal thin film in the form of a long sheet made of copper, aluminum, etc., is usually wound in a roll form. The current collector is supplied from the current collector roll and moves continuously. An active material slurry including an electrode active material and a binder is applied to one or both surfaces of a continuously moving current collector in the form of a long sheet. Among the current collectors, a portion to which the active material slurry is applied and a portion not to be applied are distinguished. This may vary depending on the size and shape of the electrode to be used. At least one portion of both ends in the longitudinal direction of the long sheet-type current collector is used as an electrode tab, and the active material slurry is also not applied to this portion.

The current collector to which the active material slurry is applied is passed through a rolling roller to form an active material coating layer having a predetermined thickness. Thereafter, an electrode tab is formed on at least one of both ends of the long sheet in the longitudinal direction using a notching device. After that, an individual electrode is manufactured using a slitter and passed through a dryer to complete the electrode. You can also dry it first by passing it through a dryer before using the slitter.

Active material slurries made in the form of a slurry for application to the current collector contain an aqueous or non-aqueous solvent, and they need to be dried. For the drying, a conventional slurry drying method is used, and drying is performed through evaporation of the solvent through heating. Drying proceeds as the current collector to which the active material slurry in the form of a long sheet is applied passes through the heating zone.

However, as a process of drying the already notched current collector sheet, it passes through many rollers during transport, thereby causing a problem that the electrode tabs are damaged.

In order to solve the above problems, notching may be performed after heating and drying. In such a case, since they are in a heated state and the thickness of the current collector is very thin, when notching through punching is performed, uneven finish may occur due to variations in the mold according to the temperature difference and the difference in elongation of the current collector.

In the process of improving the order of notching and drying, another problem that affects the quality of the battery arises. In recent years, despite the decrease in the overall volume of the secondary battery, the required capacity is increasing. Problems such as steps and uneven finishes occurring in the stacking of cells also need to be controlled more precisely.

In Patent Document 1, the electrode plate to which the active material slurry is applied is dried in a drying furnace, pressed through a rolling step, pressurized with a rolling roller, etc., and then undergoes a cutting process in a slitting step. At this time, a large bucket is arranged inside the rolling roller in the rolling step to control the temperature of the water to control the temperature of the rolling roller.

Patent Document 1 uniformly controls the degree of thermal expansion of a roll made of metal by maintaining a constant temperature in the rolling step. Through this, the gap between the rolls is kept constant. Since the distance between the rolls is kept constant, the thickness of the coated current collector can be kept constant. In Patent Document 1, the temperature of the rolling roller is kept constant, and it is not intended to solve the problem of defects caused by notching.

Patent Document 2 discloses a step of drying a slurry applied to a current collector, a step of heating a current collector, a step of pressing, and a step of cooling. Adjusting the temperature and pressurizing in Patent Document 2 is to make the applied slurry, that is, the electrode active material, more closely contacted to have a dense structure, and to increase the bonding power, and to recognize or solve the notching problem according to the temperature difference recognized in the present invention. There is not.

Patent Literature 3 is a step of processing in steps of a preheating unit, a drying unit, an annealing unit, and a cooling unit after passing through a coating treatment unit for applying an active material onto a metal foil. Patent Document 3 is for uniformly drying the applied slurry, and does not recognize the problem caused by notching to be solved in the present invention.

Patent Document 4 also relates to a drying apparatus for drying a slurry, and not only does not recognize the problem to be solved in the present invention, but also lacks a solution.

The problem of defects due to notching was not largely raised in the past, but as the thin film of the battery became thinner, the defects of punching on the notched surface had an effect on the safety of the secondary battery. Until now, in the manufacture of an electrode using a current collector in the form of a long sheet, a clear solution to the notching to be solved in the present invention has not been suggested.

Republic of Korea Patent Publication No. 2018-0115425 (2018.10.23) Republic of Korea Patent Publication No. 2015-0080745 (2015.07.10) Republic of Korea Patent Publication No. 2013-0083919 (2013.07.23) Republic of Korea Patent Publication No. 2015-0131562 (2015.11.25)

The present invention aims to solve the above problems, and proposes an improvement process in which a notching process is arranged at a rear end so that the notching quality of the final product can be excellent. As mentioned above, even in such an improved process, the object of the present invention is to provide a method of manufacturing an electrode with improved such viscosity since punching failure occurs due to a change in the temperature of the current collector due to heating and drying.

The present invention for achieving the above object is an electrode drying apparatus for manufacturing a dry electrode sheet by heating and drying an active material aggregate current collector coated with an active material on at least one surface of a long sheet-shaped current collector; An electrode cooling device for manufacturing an electrode sheet by cooling the dry electrode sheet; It provides an electrode manufacturing apparatus comprising; a notching device for manufacturing a notched electrode having an electrode tab by notching at least one side of the electrode sheet.

The electrode cooling device cools the dry electrode sheet by passing at least two cooling rolls, and specifically, the electrode cooling device includes an upper cooling roll; A lower cooling roll disposed at a lower end of the upper cooling roll; A cooling fluid supply unit for supplying a cooling fluid to the upper cooling roll and the lower cooling roll, respectively; An upper direction roll for supplying the dry electrode sheet by contacting it from an upper side of one side of the lower cooling roll; The dry electrode sheet supplied by contacting from the upper side of the lower cooling roll passes at least 1/2 of the surface of the lower cooling roll and is supplied by contacting from the lower side of the upper cooling roll, and then the upper cooling It may include a; intermediate direction roll that passes through at least 1/2 of the roll surface and is supplied to the notching device.

Another aspect of the electrode cooling device includes an upper cooling roll; A lower cooling roll disposed at a lower end of the upper cooling roll; A cooling fluid supply unit for supplying a cooling fluid to the upper cooling roll and the lower cooling roll, respectively; A lower direction roll for supplying the dry electrode sheet by contacting from a lower side of one side of the upper cooling roll; The dry electrode sheet supplied by contacting from the lower side of the upper cooling roll passes at least 1/2 of the surface of the upper cooling roll and is supplied by contacting from the upper side of the lower cooling roll, and then the lower cooling It may include a; intermediate direction roll that passes through at least 1/2 of the roll surface and is supplied to the notching device.

A specific aspect of the electrode drying device includes an upper heating device disposed on an upper end; A lower heating device disposed at a lower end of the upper heating device; And a current collector heating unit provided with a slit-shaped space through which the active material aggregate current collector can pass between the upper heating device and the lower heating device.

Another aspect of the present invention is a method of manufacturing a dry electrode sheet by heating and drying an active material aggregate current collector coated with an active material on at least one surface of a current collector in the form of a long sheet; Cooling the dry electrode sheet to prepare an electrode sheet; It provides an electrode manufacturing method comprising; manufacturing a notched electrode having an electrode tab by notching the electrode sheet.

Cooling the dry electrode sheet is to cool the dry electrode sheet by contacting two or more cooling rolls, and the two or more cooling rolls may rotate at the same speed as the moving speed of the dry electrode sheet.

When the dry electrode sheet is cooled by contacting two or more cooling rolls, the dry electrode sheet is cooled by contacting two cooling rolls disposed above and below. When the dry electrode sheet is supplied from the lower side, it first comes into contact with the upper cooling roll, passes at least 1/2 of the surface of the first contacting cooling roll, and at least 1/2 of the surface of the remaining cooling rolls. It may be that it cools as it passes.

The manufacturing of the dry electrode sheet may include heating and drying the active material assembly by a heating device disposed to face at least one surface of the active material assembly according to the moving direction of the active material assembly.

Another aspect of the present invention provides an electrode manufactured by the electrode manufacturing method.

The means for solving the above problems of the present invention may be provided in various combinations of the above-described matters.

As described above, the present invention is to solve the above problems, and fundamentally eliminates the factors that may cause defects such as breakage while the product manufactured by arranging the notching process at the rear end passes through the rolls in the process. I did.

In addition, by rapidly cooling the heated current collector using two cooling rolls, the problem of punching failure in the notching process was solved.

1 is an example of a conventional electrode manufacturing apparatus.
2 is an embodiment of an electrode manufacturing apparatus according to the present invention.
3 is another embodiment of an electrode manufacturing apparatus according to the present invention.

Hereinafter, exemplary embodiments in which the present invention can be easily implemented by those of ordinary skill in the art to which the present invention pertains will be described in detail with reference to the accompanying drawings. However, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention in describing the operating principle of the preferred embodiment of the present invention in detail, the detailed description thereof will be omitted.

In addition, the same reference numerals are used for portions having similar functions and functions throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only a case in which it is directly connected, but also a case in which it is indirectly connected with another element interposed therebetween. In addition, the inclusion of a certain component does not exclude other components unless specifically stated to the contrary, but means that other components may be further included.

The detailed description by limiting or adding constituent elements may be applied to all inventions unless there is a specific limitation, and is not limited to a specific invention.

The present invention provides an electrode drying apparatus for manufacturing a dry electrode sheet by heating and drying an active material composite current collector coated with an active material on at least one surface of a current collector; An electrode cooling device for manufacturing an electrode sheet by cooling the dry electrode sheet; It provides an electrode manufacturing apparatus including; and a manufacturing method of an electrode using the same; a notching device for manufacturing a notched electrode having an electrode tab by notching at least one side of the electrode sheet.

The problem of defects due to notching was not largely raised in the past, but as the thin film of the battery became thinner, the defects of punching on the notched surface had an effect on the safety of the secondary battery. The present invention provides an electrode manufacturing apparatus capable of solving the problem of poor punching of a notched surface and a manufacturing method according thereto.

1 is an example of a conventional electrode manufacturing apparatus 10. 1 to 3 are not schematic diagrams of the entire electrode manufacturing apparatus, but show the subsequent apparatus after a slurry containing an active material has already been applied to the electrode current collector and passed through a rolling roller. In FIGS. 1 to 3, a double-dashed line indicates that a current collector coated or coated with a slurry containing an active material is transferred.

In FIG. 1, a notching device 100 is first arranged and notched on one surface of a current collector to manufacture an electrode tab. The notched electrode passes through a plurality of rollers, passes through the electrode drying apparatus 200, and then moves to the electrode recovery unit 400. 1 to 3 are schematically illustrated as being recovered from the electrode recovery unit 400 to the electrode recovery roll 40 as a final step, but this is only an example, and the electrode recovery unit can be modified into various shapes or devices. It is obvious to a person skilled in the art that the same modification can be easily changed as needed.

The current collector passing through the notching device 100 may break the electrode in the process of passing through a roller or the like. 2 is a schematic diagram of an embodiment of an electrode manufacturing apparatus 20 according to the present invention, which has improved this problem.

An electrode drying device 200 for manufacturing a dry electrode sheet by heating and drying an active material aggregate current collector coated with an active material on at least one surface of the current collector 200, and an electrode cooling device 300 for manufacturing an electrode sheet by cooling the dried electrode sheet It provides an electrode manufacturing apparatus 20 including a notching apparatus 100 for manufacturing a finished electrode having an electrode tab by notching the electrode sheet.

Specifically, the electrode cooling device 300 includes an upper cooling roll 310, a lower cooling roll 320 disposed at a lower end of the upper cooling roll 310, the upper cooling roll 310 and the lower cooling roll 320. ), a cooling fluid supply unit 350 for supplying cooling fluid to each, an upper direction roll 330 for supplying the dry electrode sheet in contact from an upper side of one side of the lower cooling roll 320, and the lower cooling roll 320 ), the dry electrode sheet supplied by contacting from the upper side of the lower cooling roll 320 passes at least 1/2 of the surface of the lower cooling roll 320 and is supplied by contacting from the lower side of the upper cooling roll 310, and then It includes a middle direction roll 340 that passes over 1/2 or more of the surface of the upper cooling roll 310 and is supplied to the notching device 100.

The cooling fluid supply unit 350 supplies a cooling fluid to the upper cooling roll 310 and the lower cooling roll 320, and the cooling fluid is sufficient at a temperature for cooling the heated dry electrode sheet. 2 to 3 schematically supply the cooling fluid to the upper cooling roll 310 and the lower cooling roll 320 by branching the cooling fluid supply unit 350, but separately supplying cooling fluid at different temperatures. It is also possible.

2 is schematically illustrated as being supplied from the top of the dry electrode sheet, but this is according to an embodiment, and when the dry electrode sheet is supplied from the bottom, the arrangement of the dry electrode sheet may be in a form in which the top and bottom of FIG. 2 are inverted. I can.

3 is a schematic diagram of another embodiment in which the configuration of the electrode cooling device 500 is different. The electrode cooling device 500 includes an upper cooling roll 510; A lower cooling roll 520 disposed at a lower end of the upper cooling roll 510; A cooling fluid supply unit 350 for supplying cooling fluid to the upper cooling roll 510 and the lower cooling roll 520, respectively; A lower direction roll 530 for supplying the dry electrode sheet in contact from a lower side of one side of the upper cooling roll 510; The dry electrode sheet supplied by contacting from the lower side of the upper cooling roll 510 passes at least 1/2 of the surface of the upper cooling roll 510 and contacts from the upper side of the lower cooling roll 520 To be supplied, and after passing through at least 1/2 of the surface of the lower cooling roll 520 and being supplied to the notching device, a middle direction roll 340; may be included.

The cooling rolls 310, 320, 510, 520 rotate together with the movement of the drying electrode sheet, and when the drying electrode sheet directly winds and moves the surface of the cooling rolls 310, 320, 510, 520 Cooling is achieved through contact. For cooling, the cooling rolls 310, 320, 510, and 520 are preferably made of metal having high conductivity. The cooling fluid supply unit 350 is connected to the center of the cooling rolls 310, 320, 510, and 520 to supply a cooling fluid having a constant temperature. Since the temperature of the dry electrode sheet is above room temperature, cooling can be performed even if the temperature of the cooling rolls 310, 320, 510, and 520 is kept at room temperature only. Rather, if the temperature of the cooling rolls 310, 320, 510, 520 is lowered below room temperature, moisture may condense on the surface of the cooling rolls 310, 320, 510, 520, and the current collector may get wet. It is not desirable to go down. However, even if it is below room temperature, it is a dry atmosphere, so it is preferable to cool it to a temperature below the dew point.

The electrode drying apparatus 200 disposed at the front end of the commercial electrode cooling apparatuses 300 and 500 specifically includes an upper heating apparatus 210 disposed at the upper end, and a lower heating apparatus disposed at the lower end of the upper heating apparatus 210 ( 220), and a current collector heating unit 240 provided with a slit-shaped space through which the active material aggregate current collector can pass between the upper heating device 210 and the lower heating device 220.

In the electrode drying apparatus 200, a plurality of heaters 230 are disposed at portions of the upper heating apparatus 210 and the lower heating apparatus 220 that face the active material aggregate current collector. A means for measuring the temperature of the current collector is provided at the inlet and outlet portions of the electrode drying apparatus 200, respectively, to control the temperature of the current collector from excessively rising. This is because if the temperature of the current collector is too high, cracks may occur in the coating applied to the current collector, and the physical properties of the active material and the binder may change.

The notching device 100 notches one side of the electrode sheet to form an electrode tab.

The present invention provides a method of manufacturing an electrode using the device. Heating and drying an active material composite current collector coated with an active material on at least one side of a long sheet-shaped current collector to prepare a dry electrode sheet, cooling the dry electrode sheet to prepare an electrode sheet, and notching the electrode sheet It provides an electrode manufacturing method comprising the step of manufacturing a notched electrode having an electrode tab.

Cooling the dry electrode sheet is to cool the dry electrode sheet by contacting two or more cooling rolls 310, 320, 510, 520, and the cooling rolls 310, 320, 510, 520 are the drying electrode sheets. It can rotate at the same speed as the seat's movement speed.

The dry electrode sheet is cooled by contacting the two cooling rolls 310, 320, 510, 520 disposed above and below, and specifically, when the dry electrode sheet is supplied from the upper side, the lower lower cooling roll 320 First contact with and, when the dry electrode sheet is supplied from the lower side, it first contacts the upper cooling roll 510 and passes at least 1/2 of the surface of the cooling rolls 320 and 510 first contacted, and the remaining cooling rolls (310, 520) It is cooled as it passes more than half of the surface.

As shown in FIGS. 2 and 3, it is most preferable for the dry electrode sheet to pass through the cooling rolls 310, 320, 510, and 520 in a "S" shape, and each cooling roll 310, 320, 510, It is good to contact at least 1/2, preferably at least 3/4 of the entire surface of 520).

In manufacturing the dry electrode sheet, the active material assembly is heated and dried by a heating device 200 disposed to face at least one surface of the active material assembly according to the moving direction of the active material assembly.

The current collector cooled by the electrode cooling apparatuses 300 and 500 is notched through the notching apparatus 100 to be manufactured as a notched electrode.

Those of ordinary skill in the field to which the present invention belongs will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

10: Conventional electrode manufacturing apparatus
20, 30: electrode manufacturing apparatus according to the present invention
40: electrode recovery roll
100: notching device
200: electrode drying device
210: upper heating device
220: bottom heating device
230: heater
240: current collector heating unit
300, 500: electrode cooling device
310, 510: upper cooling roll
320, 520: lower cooling roll
330: top direction roll
530: downward roll
340: middle direction roll
350: cooling fluid supply unit
400: electrode recovery unit

Claims (12)

An electrode drying device for manufacturing a dried electrode sheet by heating and drying an active material composite current collector coated with an active material on at least one surface of a long sheet-shaped current collector;
An electrode cooling device for manufacturing an electrode sheet by cooling the dry electrode sheet;
A notching device for manufacturing a notched electrode having an electrode tab by notching at least one side of the electrode sheet;
Electrode manufacturing apparatus comprising a. The method of claim 1,
The electrode cooling device is an electrode manufacturing apparatus to cool the dry electrode sheet by passing through two or more cooling rolls. The method of claim 1,
The electrode cooling device includes an upper cooling roll;
A lower cooling roll disposed at a lower end of the upper cooling roll;
A cooling fluid supply unit for supplying a cooling fluid to the upper cooling roll and the lower cooling roll, respectively;
An upper direction roll for supplying the dry electrode sheet by contacting it from an upper side of one side of the lower cooling roll;
The dry electrode sheet supplied by contacting from the upper side of the lower cooling roll passes at least 1/2 of the surface of the lower cooling roll and is supplied by contacting from the lower side of the upper cooling roll, and then the upper cooling A middle direction roll that passes at least 1/2 of the roll surface and is supplied to the notching device;
The electrode manufacturing apparatus comprising a. The method of claim 1,
The electrode cooling device includes an upper cooling roll;
A lower cooling roll disposed at a lower end of the upper cooling roll;
A cooling fluid supply unit for supplying a cooling fluid to the upper cooling roll and the lower cooling roll, respectively;
A lower direction roll for supplying the dry electrode sheet by contacting from a lower side of one side of the upper cooling roll;
The dry electrode sheet supplied by contacting from the lower side of the upper cooling roll passes at least 1/2 of the surface of the upper cooling roll and is supplied by contacting from the upper side of the lower cooling roll, and then the lower cooling A middle direction roll that passes at least 1/2 of the roll surface and is supplied to the notching device;
The electrode manufacturing apparatus comprising a. The method of claim 1,
The electrode drying device includes an upper heating device disposed at the upper end;
A lower heating device disposed at a lower end of the upper heating device;
A current collector heating unit provided with a slit-shaped space through which the active material aggregate current collector can pass between the upper heating device and the lower heating device;
The electrode manufacturing apparatus comprising a. Heating and drying an active material composite current collector coated with an active material on at least one surface of a long sheet-shaped current collector to prepare a dry electrode sheet;
Cooling the dry electrode sheet to prepare an electrode sheet;
Manufacturing a notched electrode having an electrode tab by notching the electrode sheet;
Electrode manufacturing method comprising a. The method of claim 6,
Cooling the dry electrode sheet is to cool the dry electrode sheet in contact with at least two cooling rolls. The method of claim 7,
The electrode manufacturing method wherein the two or more cooling rolls rotate at the same speed as the moving speed of the dry electrode sheet. The method of claim 7,
The drying electrode sheet is cooled by contacting two or more cooling rolls to cool the dried electrode sheet by contacting two cooling rolls disposed above and below it. The method of claim 9,
Contacting the dry electrode sheet with the two cooling rolls disposed above and below is in contact with the cooling roll below when the dry electrode sheet is supplied from the upper side, and the upper side when the dry electrode sheet is supplied from the bottom. An electrode manufacturing method that first contacts the cooling roll, and is cooled while passing through at least 1/2 of the surface of the cooling roll first contacting and passing through at least 1/2 of the surface of the remaining cooling roll. The method of claim 6,
In the manufacturing of the dry electrode sheet, the active material assembly current collector is heated and dried by a heating device disposed to face at least one surface of the active material assembly current collector according to the moving direction of the active material assembly current collector. . An electrode manufactured by the electrode manufacturing method according to any one of claims 6 to 11.

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