KR101931018B1 - Manufacturing method of electrode and manufacturing apparatus of electrode - Google Patents

Abstract

In this manufacturing method, the B roll 2 transporting the assembly 10, the C roll 3 transporting the metal foil 11, and the upstream side of the C roll 3 in the transport direction of the metal foil 11 The electrode 12 is manufactured by using the manufacturing apparatus 100 having the cooling section 5 for cooling the metal foil 11 in the manufacturing process. The manufacturing apparatus 100 uses the cooling section 5 to cool the metal foil 11 and supply the metal foil 11 cooled in the cooling section 5 to the C roll 3 and the B roll 2 The assembly 10 is transferred to the metal foil 11 at the film forming gap G2 between the C roll 3 and the C roll 3. [

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electrode,

The present invention relates to a manufacturing method and an apparatus for manufacturing an electrode in which a metal foil and a layer of an active material material are laminated by transferring an active material as a material containing an active material to a metal foil.

For example, in a lithium ion secondary battery, a sheet-like electrode having an active material layer formed on the surface of a metal foil is used. For example, Japanese Laid-Open Patent Publication No. 2015-201318 discloses a method for producing a sheet-like electrode. Japanese Laid-Open Patent Application No. 2015-201318 discloses a method of forming a wet-state assembly including active material particles, a binder and a solvent in a planar or block shape, transporting the obtained formed body and a metal foil to rolls, Is transferred onto a metal foil.

However, the related art described above has the following possibility. That is, when transferring the active material to the metal foil, the active material is compressed in the gap between the surface of the roll carrying the active material and the surface of the roll carrying the metal foil, and processing heat is generated. As a result, if continuous production is continued over a long period of time, the generated heat is accumulated in the roll, and the roll tends to expand. When at least one of the rolls is expanded, the distance of the gap becomes smaller, so that the layer thickness of the active material layer of the produced electrode tends to be thin.

The present invention provides a method of manufacturing an electrode that can be expected to bring the layer thickness of the active material layer within an appropriate range even when the electrode is continuously manufactured for a long time.

A method of manufacturing an electrode in an embodiment of the present invention includes a first roll for transporting an active material that is a material containing an active material and a second roll disposed in parallel adjacent to the first roll, And the active material is transferred to the foil by rotating the first roll and the second roll in opposite directions to each other to form a layer of the active material on the surface of the foil, And cooling the foil using a cooling device on the upstream side of the second roll with respect to the conveying direction of the second roll.

According to the method of manufacturing an electrode in the above-described mode, the foil is cooled by the cooling device before reaching between the first roll and the second roll. There is a high possibility that much of the processing heat generated in the transferring process by transferring the active material to the cooled foil is consumed for raising the temperature of the foil. As a result, the accumulation of heat is suppressed in either the first roll or the second roll, and expansion of the roll is suppressed. Therefore, even when the electrode is continuously manufactured for a long time, it is expected that the thickness of the active material layer is within the appropriate range.

The cooling device includes a cooling roll. When the foil is cooled, the foil is brought into contact with the cooling roll while keeping the outer circumferential surface of the cooling roll at a temperature lower than the air temperature in the manufacturing environment, It is preferable to cool it. There is a high possibility that the foil can be uniformly cooled by bringing it into contact with the cooling roll at a low temperature.

The cooling device may further include a refrigerant supply unit for supplying a refrigerant to the cooling roll. When the foil is cooled, the refrigerant is supplied to the cooling roll at a lower temperature than the air temperature of the manufacturing environment . It is expected that the surface temperature of the cooling roll is properly maintained by supplying the refrigerant from the refrigerant supply portion.

When cooling the foil, it is preferable to cool the foil so that the temperature of the foil after cooling is lower than the air temperature of the manufacturing environment and is higher than the dew point temperature of the manufacturing environment. By making the temperature lower than the air temperature in the manufacturing environment, the cooling effect is enhanced. Further, by making the temperature higher than the dew point temperature, adhesion of water droplets to the foil can be suppressed.

The cooling device further includes a sensor for outputting different signals depending on an air temperature and a relative humidity in a manufacturing environment. When the foil is cooled, the temperature of the manufacturing environment and the relative humidity And acquiring the dew point temperature from the acquired air temperature and the relative humidity and further determining whether the temperature of the foil after cooling is lower than the acquired air temperature and higher than the acquired dew point temperature, The temperature at which the foil in the cooling device is cooled may be determined. If the information of the manufacturing environment is acquired and the temperature for cooling the foil is automatically determined based on the acquired information, the possibility of automating the manufacturing process is increased.

The method may further include heating the first roll so that the outer circumferential surface temperature of the first roll becomes a predetermined temperature or more higher than the temperature of the foil after cooling. Since the outer circumferential surface of the first roll is higher in temperature than the foil by a predetermined temperature or more, most of the generated heat is transferred to the foil. Thus, the accumulation of heat for the first roll is further suppressed.

The present invention also provides an electrode manufacturing apparatus for forming an active material layer on a surface of a foil by transferring an active material that is a material including an active material onto a foil, the apparatus comprising: a first roll for transporting the active material; A second roll disposed parallel to the first roll and carrying the foil; a second roll disposed adjacent to the first roll for transporting the foil; a second roll disposed adjacent to the first roll in contact with the foil on the upstream side of the second roll, And a cooling roll having a flow passage through which the cooling roll passes.

It is preferable that the apparatus for manufacturing an electrode further includes a refrigerant supply unit for supplying the refrigerant to the cooling roll. It is preferable that a plurality of the cooling rolls are provided. If this is the case, there is a high possibility that the foil can be reliably cooled to a proper temperature by the cooling roll.

Further, it is preferable that the apparatus for manufacturing an electrode includes a heating section for heating the first roll. Most of the heat generated by heating the first roll moves more reliably to the foil.

According to the present invention, a method of manufacturing an electrode is realized, which can be expected to bring the layer thickness of the active material layer within an appropriate range even when the electrode is continuously manufactured for a long time.

The features, advantages, and technical and industrial significance of the exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like elements are represented by like reference numerals.
1 is a schematic structural view showing a manufacturing apparatus of a first embodiment.
2 is a schematic cross-sectional view showing an example of a secondary battery.
3 is a block diagram showing the electrical configuration of the manufacturing apparatus.
4 is an explanatory diagram showing an example of the dew point temperature table.
5 is a process diagram showing a manufacturing method by the manufacturing apparatus.
Fig. 6 is a schematic diagram showing a manufacturing apparatus in which an experiment for manufacturing an electrode is performed.
7 is a graph showing the results of an experiment for manufacturing an electrode.
8 is a schematic structural view showing the manufacturing apparatus of the second embodiment.
9 is a block diagram showing an electrical configuration of the manufacturing apparatus of the second embodiment.
10 is a process diagram showing a manufacturing method by the manufacturing apparatus of the second embodiment.
11 is a graph showing the results of an experiment for manufacturing an electrode.

Hereinafter, a first embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a manufacturing apparatus used in a step of manufacturing a strip-shaped electrode.

A schematic configuration of the manufacturing apparatus 100 of this embodiment is shown in Fig. The manufacturing apparatus 100 of this embodiment is, for example, an apparatus for manufacturing a strip-shaped electrode used in a lithium ion secondary battery. The manufacturing apparatus 100 uses the plurality of rolls to transfer the assembly 10 of the active material including the active material to the metal foil 11 to form the electrodes on the laminated sheet in which the active material layer is formed on the metal foil 11 12).

The electrode 12 manufactured by the manufacturing apparatus 100 of this embodiment is used for a lithium ion secondary battery 200 of a substantially rectangular parallelepiped shape, for example, as shown in Fig. The lithium ion secondary battery 200 is formed by winding a wound electrode body 150 and an electrolyte in a battery case 110 made of metal.

The electrode body 150 is a winding body in which a strip-shaped positive electrode and a strip-shaped negative electrode are wound in a flat shape with a strip-shaped separator interposed therebetween. The electrode for positive electrode is, for example, formed by forming an active material layer containing a positive electrode active material on an aluminum foil. The active material layer of the positive electrode includes an active material capable of intercalating and deintercalating lithium ions, and is preferably, for example, a lithium-containing metal oxide kneaded with a binder and a dispersion solvent. The electrode for the negative electrode is formed by, for example, forming an active material layer containing a negative electrode active material on a copper foil. As the active material layer of the negative electrode, a carbon-based material such as graphite is preferable.

The lithium ion secondary battery 200 has a positive electrode terminal 120 and a negative electrode terminal 130 above the battery case 110 in FIG. The positive electrode terminal 120 and the negative electrode terminal 130 are connected to the electrode of the electrode of the electrode assembly 150 inside the battery case 110, respectively.

1, the manufacturing apparatus 100 of the present embodiment includes an A roll 1, a B roll 2, a C roll 3, a supply unit 4, and a cooling unit 5 Respectively. The B roll 2 is an example of the first roll and the C roll 3 is an example of the second roll. The cooling section 5 is an example of a cooling apparatus.

The A roll 1, the B roll 2 and the C roll 3 are all disposed in parallel to each other so as to be substantially horizontal. In the example shown in Fig. 1, the A roll 1 and the B roll 2 are arranged substantially horizontally side by side, and the C roll 3 is disposed below the B roll 2. However, the arrangement of the rolls is not limited to the example of this drawing. For example, all three rolls 1, 2, and 3 may be arranged horizontally side by side.

The diameter of each roll is the smallest among the three A rolls 1 and the largest among the three C rolls 3. The A roll 1 and the B roll 2 are adjacent to each other with a gap of, for example, 60 to 100 占 퐉 at the nearest point between the outer surfaces. The B roll 2 and the C roll 3 are adjacent to each other with a gap of, for example, 10 to 20 占 퐉 at the nearest point between the outer surfaces. The A roll 1 and the C roll 3 are not adjacent to each other. Hereinafter, the gap between the A roll 1 and the B roll 2 is referred to as a feed gap G1 and the gap between the B roll 2 and the C roll 3 is referred to as a film formation gap G2.

The A roll 1, the B roll 2 and the C roll 3 are connected to a motor for rotational driving, and are rotated at a predetermined rotational speed in the production of the electrode. The motors may be common to each roll or may be separate. The rotation direction of each roll is determined so that the two rolls forming the gap move in the same direction in the supply gap G1 and the film formation gap G2 which are adjacent positions of the two rolls. That is, the A roll 1 and the C roll 3 are rotated in the same rotating direction, and the B roll 2 is rotated in the rotating direction opposite to the A roll 1 or the C roll 3.

More specifically, in the example shown in Fig. 1, the outer periphery of the A roll 1 and the outer periphery of the B roll 2 move downward in Fig. 1 in the supply gap G1, and in the film formation gap G2, (2) and the outer circumferential surface of the C roll (3) move to the right in Fig. In addition, the peripheral velocity of each roll at the time of production is the slowest among the three main streams of the A roll 1 and the fastest among the three main streams of the C roll 3. The diameter and the peripheral velocity of each roll may be selected within a range capable of appropriately transferring in the film formation gap G2.

The feeding section 4 feeds the assembly 10 between the A roll 1 and the B roll 2. When manufacturing the electrode by the manufacturing apparatus 100, the assembly 10 is supplied from the supply unit 4 to the supply gap G1 as shown in Fig. The assembly 10 supplied from the supply section 4 is sandwiched between the A roll 1 and the B roll 2 at the supply gap G1 and formed into a film. The film-like assembly 10 is attached to the outer circumferential surface of the B roll 2 and is conveyed to the film formation gap G2.

The assembly 10 is assembled into a substantially spherical shape by adding a small amount of a solvent such as water to the powder containing the electrode active material and the binder, making the wet state, and stirring the powder. The powder may further contain a thickener. As the assembly 10, for example, a body obtained by making the particle size uniform to some extent may be used. Since the assembly 10 has a smaller moisture content than the material of the paste in the related art, the time required for drying is shortened by using the assembly 10.

In manufacturing the electrode using the manufacturing apparatus 100, the metal foil 11 is supplied to the film formation gap G2 by the C roll 3 as shown in Fig. The metal foil 11 is, for example, a thin metal film of 10 to 20 mu m in thickness, and an aluminum foil is used to produce a positive electrode, and a copper foil is used to produce an electrode of a negative electrode. The metal foil 11 is unwound from a supply roll or the like (not shown), and is transported to the film formation gap G2 on the outer peripheral surface of the C roll 3.

In the film formation gap G2, the assembly 10 attached to the outer peripheral surface of the B roll 2 and the metal foil 11 conveyed on the outer peripheral surface of the C roll 3 face each other. The size of the narrowest portion of the film formation gap G2 is smaller than the sum of the thickness of the assembly 10 on the B roll 2 and the thickness of the metal foil 11. As a result, the assembly 10 and the metal foil 11 are brought into pressure contact at the film forming gap G2. The assembly 10 is transferred to the metal foil 11 and becomes the electrode 12 in the laminated state because the peripheral speed of the C roll 3 is faster than the peripheral speed of the B roll 2. [ The produced electrode 12 is transported from the C roll 3 to the right in Fig. 1, and dried in a drying furnace (not shown).

As shown in Fig. 1, for example, three cooling rolls 51, 52 and 53 are provided in combination, and the cooling unit 5 is provided with a plurality of cooling rolls 51, The metal foil 11 is cooled. Each of the cooling rolls 51 to 53 is a metal roll in which a flow path of cooling water is formed. The surfaces of the cooling rolls 51 to 53 are cooled by the cooling water flowing therein, and the metal foil 11 wound on the surface is cooled. The cooling section 5 is in the conveying path of the metal foil 11 and is disposed at a position upstream of the C roll 3 with respect to the conveying direction of the metal foil 11. The metal foil 11 is cooled to a temperature within a predetermined range in the cooling section 5 and wound on the C roll 3 on the upstream side of the film formation gap G2.

As shown in Fig. 1, the cooling rolls 51 to 53 are parallel to each other and are arranged at equal intervals from each other. It is preferable that the axial length of the cooling rolls 51 to 53 is longer than the length in the direction orthogonal to the conveying direction of the metal foil 11. The outer diameter of the cooling rolls 51 to 53 is preferably large enough to wind the metal foil 11 and is preferably 50 mm or more and not more than the outer diameter of the C roll 3, for example. The winding angle of the metal foil 11 with respect to each of the cooling rolls 51 to 53 is preferably 90 degrees to 270 degrees, for example. The winding angle is an angle formed by the range of contact with the metal foil 11 in the outer periphery of the cooling rolls 51 to 53. [ If the winding angle is too small, the cooling property becomes small, and if the winding angle is too large, control of conveyance becomes difficult.

The cooling section 5 of this embodiment has auxiliary rolls 54 and 55 on the front and rear sides of the cooling rolls 51 to 53, respectively. The auxiliary rolls 54 and 55 secure the winding angle of the metal foil 11 and the cooling rolls 51 to 53 and secure the metal foil 11 so that the metal foil 11 is wound on the C roll 3 with proper tension. In order to arrange the conveying path. The cooling rolls 51 to 53 and the auxiliary rolls 54 and 55 are both rotatably provided and rotate with the movement of the metal foil 11.

The manufacturing apparatus 100 of the present embodiment further includes a chiller 6 having a pump function for circulating the cooling water to the cooling rolls 51 to 53 of the cooling section 5 and a heat exchange function for maintaining the temperature of the cooling water to be supplied Respectively. The chiller 6 is an example of a refrigerant supply unit. The chiller 6 performs heat exchange with the cooling water passing through each of the cooling rolls 51 to 53 and the cooling refrigerant provided therein and sends the cooling water maintained at the set temperature to the cooling rolls 51 to 53. The temperature of the metal foil 11 after cooling differs depending on the temperature of the metal foil 11 before cooling, the contact area between the cooling rolls 51 to 53 and the metal foil 11, and the set temperature of the chiller 6. The set temperature is a temperature for keeping the temperature of the metal foil 11 after cooling within a predetermined range. Details of the set temperature will be described later.

The flow paths of the cooling water of the cooling rolls 51 to 53 may be, for example, linear flow paths parallel to the axial direction of the respective cooling rolls, or spiral flow paths about the axial direction of the cooling rolls. Further, a plurality of flow paths may be provided, or a plurality of flow paths may be provided. The cooling rolls 51 to 53 may all be rolls of the same kind or may include different kinds of rolls. Instead of the cooling water, other liquid or gaseous refrigerant may be used.

In the manufacturing apparatus 100 of the present embodiment, the metal foil 11 is cooled in the cooling section 5 before being supplied to the upstream side in the transport direction, that is, the C roll 3, Then, the metal foil 11 in a cooled state reaches the film formation gap G2. In the film forming gap G2, the assembly 10 and the metal foil 11 are compressed, and heat is generated, for example, by friction between the members in the assembly 10. Since the metal foil 11 is cooled, the temperature of the metal foil 11 is lower than the surface temperature of the B roll 2, and the generated heat is mainly transferred to the metal foil 11 in the film forming gap G2. Thereby, the possibility that the B roll 2 or the C roll 3 is heated up is small. That is, even when the long metal foil 11 is continuously used, the possibility of accumulating heat in the B roll 2 and the C roll 3 is low and the B roll 2 and the C roll 3 ) Is suppressed. Therefore, since the possibility of reducing the size of the film formation gap G2 is small, there is a high possibility that the thickness of the active material layer of the produced electrode 12 can be maintained within an appropriate range.

In this embodiment, since the cooling unit 5 is additionally provided to cool the metal foil 11, there is no need to process the B roll 2 or the C roll 3. The B roll 2 and the C roll 3 are rolls subjected to a high precision surface treatment. For example, a B roll 2 and a C roll 3 are provided with a channel for cooling water, Processing is not easy. According to this embodiment, accumulation of heat to the B roll 2 and the C roll 3 can be suppressed while maintaining the accuracy of the B roll 2 and the C roll 3. [

Next, control of the set temperature of the chiller 6 in the production apparatus 100 will be described. The manufacturing apparatus 100 of this embodiment controls the temperature of the cooling water flowing through the flow paths of the cooling rolls 51 to 53 by controlling the set temperature of the chiller 6, The temperature of the metal foil 11 is adjusted. An example of the electrical configuration for controlling the set temperature of the chiller 6 in the manufacturing apparatus 100 is shown in the block diagram of Fig.

As shown in Fig. 3, the manufacturing apparatus 100 includes a controller 7. Fig. The controller 7 includes a CPU 71 and a storage unit 72. A temperature sensor 8 for obtaining the temperature of the metal foil 11 after cooling and a chiller 6 are connected to the controller 7 And are electrically connected.

The temperature and humidity sensor 9 is, for example, a hygrometer, and outputs signals different depending on the air temperature and the relative humidity in the vicinity of the unwinding roll of the metal foil 11. The temperature sensor 8 detects the temperature of the metal foil 11 at a position downstream of the cooling section 5 and upstream of the C roll 3 with respect to the conveying direction of the metal foil 11, . The temperature sensor 8 is, for example, a thermistor and is preferably of a non-contact type.

In the storage section 72 of the controller 7, for example, as shown in Fig. 4, a dew point temperature table 73 indicating a dew point temperature corresponding to the air temperature and the relative humidity in the manufacturing environment is stored. In addition, the dew point temperature table 73 shown in Fig. 4 is a part, and it is preferable to store a more finely divided table over a wider range of temperature and humidity.

The CPU 71 refers to the dew point temperature table 73 on the basis of the output signal of the temperature and humidity sensor 9 and the output signal of the temperature sensor 8 to determine the temperature of the metal foil 11 after cooling The set temperature of the chiller 6 is controlled. Specifically, the CPU 71 controls the set temperature of the chiller 6 so that the temperature of the metal foil 11 after cooling becomes higher than the dew point temperature and as low as possible within a range lower than the air temperature of the manufacturing environment.

Therefore, the CPU 71 acquires the air temperature and the relative humidity in the manufacturing environment based on the output signal of the temperature / humidity sensor 9. Then, the CPU 71 refers to the dew point temperature table 73 to acquire the dew point temperature corresponding to the acquired air temperature and the relative humidity. The set temperature of the chiller 6 is set to a temperature obtained by adding a predetermined margin width to the obtained dew point temperature. The margin width is a value that is greater than 0 and may be a fixed value or other variable value depending on the air temperature.

If the temperature of the metal foil 11 after cooling is not less than the air temperature of the manufacturing environment, the heat transfer effect in the film formation gap G2 becomes small. In this embodiment, since the CPU 71 sets the set temperature of the chiller 6 so that the temperature of the metal foil 11 after cooling becomes lower than the air temperature of the manufacturing environment, the heat transfer effect in the film forming gap G2 is large. In addition, when the metal foil 11 is below the dew point temperature, water droplets may adhere to the metal foil 11, and the transferability in the film forming gap G2 may be lowered. Further, when water droplets are adhered to the C roll 3 from the metal foil 11, there is a possibility that rust in the C roll 3 or peripheral driving parts may occur. In this embodiment, since the CPU 71 sets the set temperature of the chiller 6 so that the metal foil 11 does not reach the dew point temperature or less, adhesion of water droplets to the metal foil 11 is suppressed.

Next, a manufacturing method for manufacturing an electrode using the manufacturing apparatus 100 of the present embodiment will be described. As shown in Fig. 5, the manufacturing method of this embodiment includes the following steps A to F, respectively. A preparation step A for preparing the assembly 10 and the metal foil 11, an environmental condition acquiring step B for acquiring the air temperature and the relative humidity of the environment, a dew point temperature acquiring step C for acquiring the dew point temperature based on the air temperature and the relative humidity A cooling temperature determination step D for determining the set temperature of the chiller 6 based on the dew point temperature, a cooling step E for supplying cooling water to the cooling rolls 51 to 53 by driving the chiller 6, A transfer step F. for transferring the assembly 10;

In the preparation step A, the assembly 10 and the metal foil 11 are prepared. Then, as shown in Fig. 1, the metal foil 11 is wound so as to come into contact with the surfaces of the cooling rolls 51 to 53. In Fig. 1, two auxiliary rolls 54 and 55 are used, and the length of contact with the cooling rolls 51 to 53 in the conveying direction of the metal foil 11 is increased.

In the environmental condition acquiring step B, the CPU 71 acquires the air temperature and the relative humidity of the manufacturing environment based on the output signal of the temperature / humidity sensor 9.

In the dew point temperature obtaining step C, the CPU 71 refers to the dew point temperature table 73 stored in the storage unit 72, and based on the air temperature and the relative humidity acquired in the environmental condition obtaining step B, . The environmental condition obtaining step B and the dew point temperature obtaining step C may be performed before the preparing step A. The environmental condition obtaining step B and the dew point temperature obtaining step C may be performed once before the start of a series of manufacturing steps, or may be performed repeatedly at predetermined time intervals, for example.

In the cooling temperature determination step D, the set temperature of the chiller 6 is determined as the temperature at which the margin width is added to the dew point temperature acquired in the dew point temperature obtaining step C. [ In this embodiment, for example, the set temperature is set to the dew point temperature + 0.5 deg. The cooling rolls 51 to 53 are cooled so that the temperature of the metal foil 11 after cooling does not become lower than the dew point temperature even if the minimum temperature is reached within the range of the temperature control performance of the chiller 6 can do.

In the cooling step E, the chiller 6 is driven to supply cooling water to the cooling rolls 51 to 53, and the surface of the cooling rolls 51 to 53 and the rolled metal foil 11 are cooled. The timing for starting the cooling may be before the start of the transferring step F, at the start of the transferring step, or after a predetermined time has elapsed from the start of the transferring step. Alternatively, for example, after the start of the transferring process, the temperature of the B roll 2 or the temperature of the C roll 3 may reach a predetermined limit temperature.

In the transferring step F, the A roll 1, the B roll 2 and the C roll 3 are driven to rotate at a predetermined rotational speed, and the supply unit 4 feeds the assembly 10 to the supply gap G1. . The assembly 10 supplied to the supply gap G1 is transported to the film formation gap G2 by the B roll 2 and transferred to the metal foil 11 in the film formation gap G2. Thereby, the electrode 12 is manufactured. After the cooling process E is started as described above, the cooling process E and the transfer process F are executed in parallel.

In the manufacturing method of this embodiment, the CPU 71 monitors the temperature of the metal foil 11 and performs feedback control after the start of the transfer step, as shown in Fig. Specifically, the CPU 71 acquires the temperature of the metal foil 11 on the basis of the output signal of the temperature sensor 8 in the night temperature obtaining step G. The CPU 71 determines whether the temperature acquired in the night temperature acquisition step G is within a proper temperature range with respect to the air temperature acquired in the environmental condition acquisition step B or the dew point temperature acquired in the dew point temperature acquisition step C . When the environmental condition obtaining step B and the dew point temperature obtaining step C are repeatedly performed, the judging step H may be judged based on the newly acquired air temperature and dew point temperature.

If the CPU 71 determines that the temperature is not within the proper temperature range, the CPU 71 returns to the cooling temperature determination step D to change the set temperature of the chiller 6. For example, when the CPU 71 determines that the temperature of the metal foil 11 is too high as compared with the dew point temperature, the CPU 71 changes the set temperature of the chiller 6 to a lower temperature. For example, the set temperature of the chiller 6 is equal to the dew point temperature. Further, when the CPU 71 determines that the temperature of the metal foil 11 is too close to the dew point temperature, the CPU 71 changes the set temperature of the chiller 6 to a higher temperature. For example, the set temperature of the chiller 6 is set to the dew point temperature + 1.0 占 폚.

On the other hand, if it is determined that the temperature is within the proper temperature range, the CPU 71 determines whether or not to terminate the manufacturing process (end determination step I). When not finished, the temperature of the metal foil 11 is appropriately obtained, feedback control is performed, and manufacturing is continued. When it is determined that the manufacturing process is finished, the rotational drive of the B roll (2) or the C roll (3) and the drive of the chiller (6) are stopped.

Next, the results of the experiment performed by the inventors on the production method of this embodiment will be described. The inventors manufactured the electrode by the manufacturing apparatus 100 of the present embodiment and compared it with the manufacturing result by the related art apparatus not including the cooling unit 5. [ The manufacturing apparatus 100 used in the experiment is provided with one cooling roll 501 and two auxiliary rolls 502 and 503 on both sides of the cooling roll 5 as a cooling unit 5 . The contact area between the cooling roll 501 and the metal foil 11 is ensured by the two auxiliary rolls 502 and 503. [

In this experiment, a positive electrode assembly was used as the assembly 10 with a solid content of 78%, and an aluminum foil with a thickness of 12 탆 was used as the metal foil 11 to produce a positive electrode. Further, a commercially available cooling roll having an outer diameter of 50 mm was used as the cooling roll 501, and a winding angle was set to about 180 degrees. As the chiller 6, a commercially available tabletop type miniature low-temperature constant-temperature water bath was used.

The production environment when the experiment was conducted was an air temperature of about 23 ± 2 ° C and a relative humidity of about 50 ± 10%. In this environmental condition, the dew point temperature is in the range of about 6.9 to 16.7 캜. Thus, the set temperature of the chiller 6 was set at 17.5 ± 0.5 ° C.

In this experiment, the metal foil 11 was transported at a transporting speed of 30 to 60 m / min, the above-described assembly 10 was supplied, and the electrode 12 was continuously manufactured for about 10 minutes. The change in the weight per unit area of the layer of the assembly 10 in the manufactured electrode 12 is shown in Fig. 7, the vertical axis indicates the weight per unit area, and the horizontal axis indicates the length of the electrode 12 continuously produced, and the result of the manufacture by the manufacturing apparatus 100 of this embodiment provided with the cooling section 5 is shown in The solid line and the result of the manufacturing apparatus in which the cooling section 5 is not provided are indicated by broken lines. The weight per unit area is the weight of the assembly 10 in the unit area of the electrode 12 after production. In the experiment, a portion of a predetermined area was cut out from the produced electrode 12, the assembly 10 was peeled from the metal foil 11, and its weight was measured to calculate the weight per unit area.

As shown by the solid line in Fig. 7, the weight per unit area of the electrode 12 manufactured by the manufacturing apparatus 100 of the present embodiment was within the range of the standard even if it was manufactured continuously for a long time. The specification range of the weight per unit area is the range indicated by the one-dot chain line in Fig. That is, it was confirmed that even if the metal foil 11 was cooled continuously, the weight per unit area was not reduced, and the thickness of the layer 10 and the weight per unit area could be maintained within an appropriate range. On the other hand, as shown by the broken line in FIG. 7, in the related art apparatus in which the cooling section 5 is not provided, the weight per unit area gradually decreased as the continuous production was performed.

As described above in detail, according to the method of manufacturing the electrode of the first embodiment, the metal foil 11 is cooled by the cooling portion 5 at a position on the upstream side of the C roll 3, (G2). Therefore, the processing heat generated in the film formation gap G2 is easily taken by the metal foil 11, so that the rise of the temperature is suppressed in both of the B roll 2 and the C roll 3. [ Therefore, even when the production is continuously performed for a long period of time, the possibility that the film formation gap G2 is small is small, and the thickness and the weight per unit area of the assembly 10 in the manufactured electrode 12 can be maintained within an appropriate range It is likely.

Next, a second embodiment of the present invention will be described in detail with reference to the accompanying drawings. This embodiment is the same as the first embodiment except that the present invention is applied to a manufacturing apparatus used in a step of manufacturing a strip-shaped electrode. The same components and processes as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

The schematic configuration of the manufacturing apparatus 1000 of the second embodiment is shown in Fig. The manufacturing apparatus 1000 of the present embodiment is an apparatus for manufacturing a strip-shaped electrode used in, for example, a lithium ion secondary battery as in the first embodiment. The manufacturing apparatus 1000 includes an electrode (not shown) on a laminate sheet on which a layer of an active material is formed on a metal foil 11 by transferring an assembly 10, which is an active material containing an active material, 12).

The manufacturing apparatus 1000 of the present embodiment is provided with the A roll 1, the B roll 2, the C roll 3, the supply unit 4, the cooling unit 5, and the cooling unit 5 A chiller 6 for cooling the rolls 51 to 53, and a heating unit 20. [ The heating unit 20 includes a heater 21 and a temperature sensor 22. [ The members other than the heating unit 20 are the same as those of the first embodiment.

The heater 21 is, for example, a nichrome wire electric heater and warms at least the outer circumferential surface of the B roll 2 as uniformly as possible over the entirety in the rotational axis direction. As shown in Fig. 8, the heater 21 is provided at a position where it does not contact the B roll 2 on the outer peripheral side of the B roll 2. The heater 21 may be a heating member other than a nichrome wire such as a halogen heater or a ceramic heater, or an electromagnetic induction heating system provided with a coil. Further, the heater 21 may be provided in a cavity provided on the inner peripheral side of the B roll 2.

The temperature sensor 22 is, for example, a thermistor, and outputs different signals depending on the outer circumferential surface temperature of the B roll 2. The temperature sensor 22 may directly measure the surface temperature of the B roll 2 and may estimate the surface temperature of the B roll 2 from the measurement result such as the rotational axis temperature of the B roll 2, The temperature of the portion may be measured. The number of temperature sensors 22 may be one, or a plurality of temperature sensors 22 may be provided.

An example of the electrical configuration of the manufacturing apparatus 1000 of this embodiment is shown in Fig. The manufacturing apparatus 1000 includes a controller 70 for controlling the temperature of each section. The controller 70 is electrically connected to the temperature and humidity sensor 9, the temperature sensor 8, the chiller 6, the heater 21, and the temperature sensor 22. The temperature and humidity sensor 9, the temperature sensor 8 and the chiller 6 are the same as those of the first embodiment. The controller 70 controls the temperature of the cooling unit 5 and the temperature of the heating unit 20. [

The controller 70 determines the set temperature of the chiller 6 based on the output signal of the temperature / humidity sensor 9 and the output signal of the temperature sensor 8, as in the first embodiment. The controller 70 also determines the target temperature of the heating section 20 based on the set temperature of the determined chiller 6. The controller 70 determines the target temperature of the heating section 20 so that the surface temperature of the B roll 2 becomes higher than the predetermined temperature by a temperature lower than the temperature of the metal foil 11 cooled by the cooling section 5 do. Specifically, the controller 70 determines the surface target temperature of the B roll 2 so that the temperature difference with respect to the set temperature of the metal foil 11 is within the range of 10 占 폚 or more and less than 25 占 폚. It is more preferable that the temperature difference is within the range of 15 deg. C or more and less than 20 deg.

Further, the controller 70 controls the heater 21 based on the output signal of the temperature sensor 22. The controller 70 controls the surface temperature of the B roll 2 to be within a predetermined temperature range with respect to the determined target temperature. The predetermined temperature range is, for example, the target temperature ± 1 ° C. The controller 70 turns off the heater 21 when the surface temperature of the B roll 2 becomes equal to or more than the upper limit of the predetermined temperature range and the surface temperature of the B roll 2 reaches the predetermined temperature range The heater 21 is turned on.

In this embodiment, the assembly 10 is transported toward the film formation gap G2 by the heated B roll 2. The assembly 10 is sandwiched between the metal foil 11 and the B roll 2 and compressed in the film forming gap G2 between the B roll 2 and the C roll 3. [ As a result, heat is generated, for example, by friction between the bodies in the assembly 10.

Heat generated in the assembly 10 is transferred from the film formation gap G2 to the peripheral member. Since the B roll 2 is already heated, it is at least higher in temperature than the assembly 10 before reaching the film forming gap G2. On the other hand, since the metal foil 11 is cooled, the temperature is lower than that of the assembly 10. As a result, the heat generated in the assembly 10 moves to the side of the metal foil 11 with a lower temperature, and the amount of heat to move to the B roll 2 side is smaller than in the case of the first embodiment.

The heating section 20 for heating the B roll 2 is controlled by the controller 70. [ When the surface temperature of the B roll 2 becomes higher than the target temperature, the heater 21 is turned off by the controller 70, so that the surface temperature of the B roll 2 is likely to be the target temperature soon .

Therefore, the accumulation of heat in the B roll 2 and the expansion of the B roll 2 due to the result are suppressed more than in the first embodiment. That is, even when the long metal foil 11 is used to continuously produce electrodes, the diameters of the B roll 2 and the C roll 3 are hard to change. As a result, the possibility that the size of the film formation gap G2 changes after the start of production is small, so that there is a high possibility that the thickness of the active material layer of the manufactured electrode 12 can be kept within a proper range. In this embodiment, the rolls 2 and 3 may be arranged so that the film-forming gap G2 has a predetermined size based on the diameter of the B-roll 2 after the object has been heated to the target temperature.

Next, a manufacturing method for manufacturing an electrode using the manufacturing apparatus 1000 of the present embodiment will be described. In the manufacturing method of this embodiment, the controller 70 carries out a manufacturing process including the following steps A, J, B, C, D, K, L and F as shown in Fig. The respective steps of A, B, C, D and F are the same as those of the first embodiment. The preparation step A for preparing the assembly 10 and the metal foil 11, the heating step J for heating the B roll 2, the environmental condition obtaining step B for obtaining the air temperature and the relative humidity of the environment, the air temperature and the relative humidity A dew point temperature obtaining step C for obtaining a dew point temperature based on the dew point temperature, a cooling temperature determining step D for determining a set temperature of the chiller 6 based on the dew point temperature, a heating temperature determining step K for determining a target temperature of the B roll 2 A cooling and heating step L for performing cooling by the cooling part 5 and heating by the heating part 20, and a transfer step F for transferring the assembly 10 to the metal foil 11.

In the warming step J, the B roll 2 is heated from a normal temperature state to a predetermined target temperature set in advance. The temporary target temperature is, for example, 35 占 폚. In this embodiment, the warming step J is performed before the environmental condition is acquired in the environmental condition acquiring step B, and the environmental temperature is acquired in the next environmental condition acquiring step B after the temperature of the B roll 2 is stabilized. The heating step J may be performed before the preparation step A.

In the heating temperature determination step K, the target temperature of the heating section 20 is determined based on the set temperature determined in the cooling temperature determination step D. [ As described above, the target temperature of the warming section 20 may be set to be at least 10 캜 or more, more preferably 15 캜 or more higher than the set temperature of the cooling section 5.

In the cooling and warming-up process L, the metal foil 11 is cooled as described in the cooling step E of the first embodiment, and the B roll 2 is heated by the heating unit 20. Then, after the B roll 2 reaches the target temperature, the transfer of the metal foil 11 is started in the transferring step F. In the case where the target temperature determined in the heating temperature determination step K is largely deviated from the temporary target temperature, the steps B to D are carried out before the transfer step F is started after the heating is started in the cooling and warming step L You can do it again.

Also in this embodiment, feedback control is performed similarly to the first embodiment. In the temperature acquisition step M, not only the temperature of the metal foil 11 but also the temperature of the B roll 2 is obtained. In the determining step H, it is determined whether or not the temperature is within the proper temperature range, and the temperature of the cooling unit 5 and the temperature of the heating unit 20 are adjusted. That is, the controller 70 controls the heater 21 so that the surface temperature of the B roll 2 is within the predetermined temperature range from the target temperature. Further, the processes of L to H are repeated until it is determined that the process is finished in the termination judgment process I.

Next, the results of the experiment performed by the inventors on the production method of this embodiment will be described. The inventor of the present invention fabricated the electrode by the manufacturing apparatus 1000 of the present embodiment and found that the manufacturing result by the apparatus of the related art and the manufacturing by the first type manufacturing apparatus in which only the metal foil 11 was cooled The results were compared. The configuration of the cooling unit 5 is the same as the experiment performed in the first embodiment.

In this experiment, a cathode assembly having a solid content of 72% was used as the assembly 10, and an aluminum foil having a thickness of 12 탆 was used as the metal foil 11 to produce a positive electrode. The metal foil 11 was transported at a transporting speed of 30 to 60 m / min, the assembly 10 was supplied, and the electrode 12 was continuously manufactured for about 10 minutes. Then, the electrode 12 was manufactured while measuring the weight per unit area of the manufactured portion by in-line measurement, and the fluctuation of the weight per unit area was confirmed. The specifications of the components of the assembly 10 and the weight per unit area are different from those in the experiment described in the first embodiment.

The results of the experiment are shown in the graph of Fig. In this graph, the vertical axis indicates the weight per unit area, and the horizontal axis indicates the length of the electrode 12 continuously produced. In this graph, the results of the manufacturing apparatus 1000 of the present embodiment are shown by thick solid lines, the results of the first manufacturing apparatus 100 are shown by thin solid lines, and the results of the related art manufacturing apparatus are shown by broken lines. The specification range of the weight per unit area in this experiment is the range indicated by the one-dot chain line in Fig.

As shown in Fig. 11, the weight per unit area of the electrode 12 manufactured by the related art manufacturing apparatus gradually decreased, and fell below the standard range at the film forming distance P1 in the drawing. The weight per unit area of the electrode 12 manufactured by the manufacturing apparatus 100 of the first embodiment gradually decreased but did not fall below the standard range up to the film forming distance P2 which was considerably longer than the film forming distance P1 of the related art. From these experimental results, according to the manufacturing apparatus 100 of the first embodiment, it was possible to manufacture continuously for a long period of time while keeping the weight per unit area within a proper range, as compared with the related art. That is, the effect of the present invention can be obtained also by the first embodiment in which the cooling section 5 is provided and the warming section 20 is not provided.

On the other hand, according to the manufacturing apparatus 1000 of the second embodiment, as shown in Fig. 11, continuous manufacturing with maintaining the weight per unit area within an appropriate range is performed for a longer period of time than the manufacturing apparatus 100 of the first embodiment It was possible. That is, according to the manufacturing apparatus 1000 of the second embodiment including both the cooling section 5 and the warming section 20, a better effect than that of the first embodiment is obtained.

As described above in detail, according to the method of manufacturing the electrode of the second embodiment, the assembly 10 is configured such that, in the film formation gap G2, the metal foil 11 cooled in the cooling section 5 and the metal foil 11 heated in the heating section 20 B roll 2, as shown in Fig. As a result, the processing heat generated in the assembly 10 positively moves toward the metal foil 11, so that the temperature rise of the B roll 2 is further suppressed than in the first embodiment. Therefore, even when the production is continuously performed for a long period of time, the possibility that the film formation gap G2 is small is small, and the thickness and the weight per unit area of the assembly 10 in the manufactured electrode 12 can be maintained within an appropriate range It is likely.

The present embodiment is merely an example, and is not intended to limit the present invention at all. Accordingly, the present invention can be variously modified and modified without departing from the gist of course. For example, the present invention is applicable not only to an electrode for a lithium ion secondary battery, but also to a method for manufacturing an electrode of various batteries, so long as it is a manufacturing method for producing a sheet-like electrode by forming a layer of a powder material on a metal plate.

The configuration of the manufacturing apparatus 100 is not limited to the example shown in the embodiment. For example, the arrangement of the rolls 1, 2 and 3, the roll diameter, and the size of the gap between the rolls are not limited to the illustrated examples. For example, as rolls 1, 2 and 3, rolls of the same diameter may be used. Further, the method of supplying the assembly 10 is not limited to putting it between the A roll 1 and the B roll 2. That is, the A roll 1 may be omitted.

In the embodiment, the group of three cooling rolls 51 to 53 is shown in Fig. 1, but any number of cooling rolls may be used as long as the number of cooling rolls is one or more. However, it is preferable that a plurality is provided because the cooling ability is high. In the embodiment, the cooling rolls 51 to 53 are rotatable. However, at least one of them may be provided with a rotational driving force, and the metal foil 11 may be conveyed. The auxiliary roll may be omitted.

1, the cooling water is supplied from one chiller 6 to each of the three cooling rolls 51 to 53. However, even if the cooling water passes through the three cooling rolls 51 to 53 sequentially do. Alternatively, each of the cooling rolls 51 to 53 may be provided with respective chillers. In this way, for example, the cooling rolls 51 to 53 can supply cooling water at different temperatures. The cooling method by the cooling unit 5 is not limited to the cooling roll. For example, the cooling chamber may be passed through the metal foil, or cool air may be sprayed to the metal foil.

In addition, in the manufacturing apparatus 100, it is not necessary to control the set temperature of the chiller 6 by the CPU 71. [ That is, B to D in Fig. 5 may be omitted. For example, the metal foil 11 may be cooled to a temperature below the dew point temperature. However, if the temperature is controlled to be higher than the dew point temperature, adhesion of water droplets to the metal foil 11 can be suppressed, which is preferable. In addition, feedback control may not be performed. That is, G and H in FIG. 5 may be omitted. However, it is more preferable to perform the feedback control because a more suitable temperature can be approached. When the temperature control is not performed, the dew point temperature table 73 of the temperature sensor 8, the temperature / humidity sensor 9, and the storage unit 72 is unnecessary.

Further, in a case where the manufacturing environment has changed in the feedback control, the manufacturing environment may be adjusted by using an air conditioner or an air dryer.

In the manufacturing apparatus 1000, the set temperature of the cooling section 5 and the set temperature of the warming section 20 may be set to a temperature difference of a predetermined temperature or more, either of which may be determined first or independently of each other . Further, the controller for controlling the chiller 6 and the controller for controlling the heater 21 are not limited to one, and may be a separate unit.

The order of execution of the heating process J is not limited to that shown in Fig. 10, and the heating process J may be performed later than B to D. Alternatively, the heating step J may be omitted. For example, after the heating temperature is determined in the heating temperature determination step K, it may be heated in the cooling warm-up step L.

Further, temperature control or feedback control of the warming section 20 may be omitted. In this case, the temperature sensor 22 may be omitted. For example, after the heating by the heater 21 is started, the heating may be continued. However, in the configuration in which the temperature is continuously increased, there is a possibility that the surface of the B roll 2 becomes too hot, the B roll 2 swells and the weight per unit area of the electrode 12 becomes small, Do.

Claims (10)

A first roll 2 for conveying an active material which is a material containing an active material and a second roll 3 arranged in parallel adjacent to the first roll 2 and conveying the foil 11 are used , The active material is transferred to the foil 11 by rotating the first roll 2 and the second roll 3 in opposite directions to form a layer of the active material on the surface of the foil 11 A method of manufacturing an electrode (12)
And cooling the foil (11) using a cooling device (5) on the upstream side of the second roll (3) with respect to the conveying direction of the foil (11)
When cooling the foil 11, the foil 11 is cooled so that the temperature of the foil 11 after cooling is lower than the air temperature of the manufacturing environment and higher than the dew point temperature of the manufacturing environment (12). The method according to claim 1,
The cooling device (5) has a cooling roll (51; 52; 53)
The foil 11 is cooled by the cooling roll 51 (52; 53) while keeping the outer circumferential surface of the cooling roll 51 (52; 53) at a temperature lower than the air temperature of the manufacturing environment, To cool the foil (11). 3. The method of claim 2,
The cooling device (5) has a coolant supply part (6) for supplying coolant to the cooling rolls (51; 52; 53)
Wherein the coolant is supplied to the cooling rolls (51; 52; 53) at a temperature lower than the air temperature of the manufacturing environment in the coolant supply unit (6) when cooling the foil (11). delete The method according to claim 1,
The cooling device (5) has a sensor (9) for outputting different signals according to the air temperature and relative humidity of the manufacturing environment,
When cooling the foil 11, the air temperature and the relative humidity of the manufacturing environment are acquired based on the output signal of the sensor 9, the dew point temperature is acquired from the acquired air temperature and the relative humidity, The temperature at which the foil 11 in the cooling device 5 is cooled so that the temperature of the foil 11 after cooling is lower than the obtained air temperature and higher than the obtained dew point temperature (12). 4. The method according to any one of claims 1 to 3,
Further comprising heating the first roll (2) so that the temperature of the outer circumferential surface of the first roll (2) becomes a temperature higher than the temperature of the foil (11) after cooling by a predetermined temperature or more Way. An apparatus for manufacturing an electrode (12) for forming an active material layer on a surface of a foil (11) by transferring an active material, which is a material including an active material, to a foil (11)
A first roll (2) for carrying the active material,
A second roll (3) disposed in parallel adjacent to the first roll (2) and carrying the foil (11)
A cooling roll (51; 52; 52) provided at a position in contact with the foil (11) on the upstream side of the second roll (3) with respect to the conveying direction of the foil (11) 53,
And a heating section (20) for heating the first roll (2). 8. The method of claim 7,
Further comprising a coolant supply unit (6) for supplying the coolant to the cooling rolls (51; 52; 53). 9. The method according to claim 7 or 8,
Wherein the plurality of cooling rolls (51; 52; 53) are provided. delete

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