KR20230064201A - Hot pressing device - Google Patents

Abstract

The present invention relates to a hot pressing device, comprising: an upper plate including a first heating plate and a first polymer coating layer disposed on one surface of the first heating plate; and a lower plate that is spaced apart from the upper plate at an opposite side and includes a second heating plate and a second polymer coating layer disposed on one surface of the second heating plate, wherein at least one of the upper plate and the lower plate is movable, and the first polymer coating layer and the second polymer coating layer each contain polyetheretherketone. Thus, the hot pressing device can improve a phenomenon of a secondary battery being attached to the upper plate and lower plate in a step of applying heat and pressure to a pouch-type secondary battery.

Description

Hot pressing device {HOT PRESSING DEVICE}

The present invention relates to a hot pressing device, and more specifically, to a hot pressing device in which an upper plate and a lower plate of the hot pressing device each include a polymer coating layer containing polyether ether ketone.

Demand for lithium secondary batteries as an energy source is rapidly increasing with the development of technologies such as electric vehicles and portable electronic devices.

Lithium secondary batteries may be classified into cylindrical, prismatic, and pouch-type batteries according to the shape of a battery case. Among them, the pouch-type battery manufactures a pouch by molding a film laminate composed of a sealant layer of a polymer material, a barrier layer of a metal material, and a substrate layer that protects the barrier layer, forming a cup portion to manufacture a pouch, and electrodes in the cup portion of the pouch. It is manufactured by sealing after housing the assembly and the electrolyte.

More specifically, the pouch-type secondary battery manufactures an electrode assembly in which a separator is interposed between the positive electrode and the negative electrode, inserts the electrode assembly into the pouch, injects an electrolyte, activates charging and discharging, and then It is manufactured by a method of performing degassing to remove gas. The degassing process is performed by opening a portion of the edge of the pouch to form an opening, and then discharging gas inside the pouch through the opening by vacuum. Meanwhile, after the gas is discharged through the degassing process, a hot press step of sealing the pouch by re-sealing the opening portion and applying heat and pressure to the pouch may be performed.

The hot pressing step may be performed by a hot pressing device. For example, the hot pressing device includes an upper plate and a lower plate, and may press the pouch-type secondary battery into which the electrode assembly is inserted using the upper and lower plates. However, defects such as the secondary battery being attached to the upper plate of the hot pressing device and falling or being displaced from the lower plate frequently occur after such pressing.

In order to solve this problem, a method of coating Teflon on the upper and lower plates has been developed, but even in this case, secondary batteries are still attached to the upper and lower plates due to the adhesion of the Teflon coating.

Meanwhile, a method of mounting the leaf spring on the upper plate has been developed to solve the above problem, but in this case, the attachment of the secondary battery to the upper plate is reduced, but a large amount of foreign substances between the upper plate and the leaf spring have been developed. However, since the plate spring could not be applied to the lower plate, the phenomenon that the secondary battery was attached to the lower plate still occurred.

One object of the present invention is to solve the above-mentioned problems, in the step of applying heat and pressure to the pouch-type secondary battery, the secondary battery is attached to the upper plate and the lower plate. To provide a hot pressing device for improving the phenomenon will be.

The present invention, an upper plate including a first heating plate and a first polymer coating layer disposed on one surface of the first heating plate; and a lower plate facing and spaced apart from the upper plate and including a second heating plate and a second polymer coating layer disposed on one side of the second heating plate, wherein at least one of the upper plate and the lower plate is movable. And, the first polymer coating layer and the second polymer coating layer each contain polyether ether ketone, and provides a hot pressing device.

The hot pressing apparatus according to the present invention is characterized in that the upper plate and the lower plate each include a first polymer coating layer and a second polymer coating layer containing polyether ether ketone. Specifically, since the first polymer coating layer and the second polymer coating layer each contain polyether ether ketone and have a low level of adhesion, when performing a hot pressing process using a hot pressing device, the object is attached to the upper and / or lower plate defects can be prevented. In particular, the hot pressing device according to the present invention can be preferably used when performing a hot pressing process of a secondary battery, specifically a pouch-type secondary battery.

1 is a perspective view schematically showing a hot pressing apparatus according to an embodiment of the present invention.
2 is a schematic view of side cross-sections of upper and lower plates of a hot pressing apparatus according to an embodiment of the present invention.
3 is a perspective view schematically illustrating a hot pressing apparatus according to another embodiment of the present invention.
4 is a schematic view of side cross-sections of upper and lower plates of a hot pressing apparatus according to another embodiment of the present invention.
5 is a schematic perspective view of an upper plate of a hot pressing apparatus according to another embodiment of the present invention.

The terms or words used in this specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to explain their invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

Hereinafter, the hot pressing device will be described in detail with reference to the drawings.

hot pressing device

A hot pressing device according to the present invention may be a device for performing a hot pressing process in which heat and pressure are applied to an object. The hot-pressing device may be preferably used in a hot-pressing process of a secondary battery, specifically, a pouch-type secondary battery.

1 is a perspective view schematically showing a hot pressing device according to an embodiment of the present invention, and FIG. 2 is a schematic view showing a side cross-section of an upper plate of the hot pressing device according to an embodiment of the present invention. .

Specifically, referring to FIG. 1 , the hot pressing device 10 includes a first heating plate 110 and an upper plate 100 including a first polymer coating layer 120 disposed on one side of the first heating plate 110. ); and a lower plate 200 facing and spaced apart from the upper plate 100 and including a second heating plate 210 and a second polymeric coating layer 220 disposed on one side of the second heating plate 210. And, at least one of the upper plate 100 and the lower plate 200 is movable, and the first polymer coating layer 120 and the second polymer coating layer 220 each contain polyetheretherketone. to be characterized

The hot pressing device 10 includes an upper plate 100 and a lower plate 200 . At least one of the upper plate 100 and the lower plate 200 is movable.

The top plate 100 is placed on top of the hot pressing device 10 .

The upper plate 100 is movable, specifically, movable upward and downward. As the upper plate 100 moves upward and downward, the upper plate 100 and the lower plate 200 approach each other so that the object S can be pressed.

The upper plate 100 may be moved by, for example, the first connecting member 130 . Specifically, the upper plate 100 may be connected to an elevating/lowering driving means (not shown) through the first connecting member 130 . The lifting and lowering driving unit may move the first connecting member 130 upward or downward using, for example, a hydraulic cylinder, and thus the upper plate 100 connected to the first connecting member 130. ) is moved up or down.

As shown in FIGS. 1 and 2 , the upper plate 100 includes a first heating plate 110 and a first polymer coating layer 120 disposed on one surface of the first heating plate 110 .

The first heating plate 110 may apply heat and pressure to the object (S).

The first heating plate 110 may have a rectangular flat shape as shown in FIG. 1 , but is not necessarily limited thereto, and may have various shapes commonly used in the hot pressing device 10 .

The first heating plate 110 may include metal. For example, the first heating plate 110 may be one or more selected from the group consisting of aluminum, iron, copper, and zinc, and preferably may effectively transfer heat to the object S and provide an appropriate load. In terms of being, aluminum may be included. When the first heating plate 110 includes the metal, even when the first heating plate 110 presses the object S with high pressure, the first heating plate 110 is not deformed and has excellent thermal conductivity. The first heating plate 110 can effectively transfer heat to the object (S).

The thickness t ₁₁₀ of the first heating plate 110 may be 10 mm to 40 mm, specifically 15 mm to 35 mm, and more specifically 20 mm to 30 mm. When the thickness (t ₁₁₀ ) of the first heating plate 110 satisfies the above numerical range, the first heating plate 110 can apply sufficient heat and pressure to the object S, so that the thickness of the object S is the target value can be easily reached, and wrinkles formed on the surface of the object (S) can be easily removed.

The first polymer coating layer 120 may be disposed on one surface of the first heating plate 110 .

As shown in FIG. 1 , the first polymer coating layer 120 may be disposed on the lowermost layer of the upper plate 100 . In this case, when pressurized using the upper plate 100 and the lower plate 200, the object S placed between the upper plate 100 and the lower plate 200 and the first polymer coating layer 120 may directly come into contact with each other. There is, the problem that the object (S) is attached to the upper plate 100 after pressing can be prevented.

The first polymer coating layer 120 may be formed by coating one surface of the first heating plate 110 . For example, the first polymer coating layer 120 may be formed by coating one surface of the first heating plate 110 with a solution containing a polymer capable of achieving an elastic modulus of the first polymer coating layer.

The lower plate 200 is disposed under the hot pressing device. The lower plate 200 can be moved from the top to the bottom or from the bottom to the top of the hot pressing device, and the object S can be pressed by moving the lower plate 200 upward. The movement of the lower plate 200 may be performed by, for example, the second connecting member 230 . Similar to the case of the upper plate 100 , the lower plate 200 may be connected to an elevating/lowering driving means (not shown) through the second connecting member 230 . The lifting and lowering driving unit may move the second connecting member 230 upward or downward using, for example, a hydraulic cylinder, and thus the lower plate connected to the second connecting member 130 ( 200) can be moved up or down.

The lower plate 200 faces the upper plate and is spaced apart, and includes a second heating plate 210 and a second polymer coating layer 220 disposed on one side of the second heating plate 210 .

The second heating plate 210 may include metal. For example, the second heating plate 210 may include one or more selected from the group consisting of aluminum, iron, copper, and zinc, and may effectively transfer heat to the object S and provide an appropriate load. In terms of possible, it may include aluminum. When the second heating plate 210 includes the metal, there is no deformation of the second heating plate 210 even when the second heating plate 210 presses the object S with high pressure, and the thermal conductivity is excellent. The second heating plate 210 can effectively transfer heat to the object S.

The thickness t ₂₁₀ of the second heating plate 210 may be 10 mm to 40 mm, specifically 15 mm to 35 mm, and more specifically 20 mm to 30 mm. When the thickness (t ₂₁₀ ) of the second heating plate 210 satisfies the above numerical range, the thickness of the object S is the target value because the second heating plate 210 can apply sufficient heat and pressure to the object S. can be easily reached, and wrinkles formed on the surface of the object (S) can be easily removed.

The second polymer coating layer 220 may be disposed on one surface of the second heating plate 210 .

As shown in FIG. 1 , the second polymer coating layer 220 may be disposed on the uppermost layer of the lower plate 200 . In this case, when pressurized using the upper plate 100 and the lower plate 200, the object S placed between the upper plate 100 and the lower plate 200 and the second polymer coating layer 220 may directly come into contact with each other. There is, it is possible to prevent the problem that the object (S) is attached to the lower plate (200) after pressing.

The second polymer coating layer 220 may be formed by coating one surface of the second heating plate 210 . For example, the second polymer coating layer 220 may be formed by coating one surface of the second heating plate 210 with a solution containing a polymer capable of achieving an elastic modulus of the second polymer coating layer 220 .

The first polymeric coating layer 120 and the second polymeric coating layer 220 may be disposed facing each other. In this case, the upper plate 110 and the lower plate 120 approach each other to apply heat and pressure to the object S. In the case of applying, the first polymer coating layer 120 and the second polymer coating layer 220 may directly contact the object (S). As will be described later, the first polymer coating layer 120 and the second polymer coating layer 220 contain polyether ether ketone, so that the object S is not attached to the upper plate 100 and the lower plate 200 and is easily can be separated

The first polymer coating layer 120 and the second polymer coating layer 220 may each include polyetheretherketone (PEEK).

The polyether ether ketone is a linear aromatic crystalline thermoplastic polymer, and has high hardness and excellent corrosion resistance, wear resistance and thermal stability.

When the first polymer coating layer 120 and the second polymer coating layer 220 each contain the polyether ether ketone, the first polymer coating layer 120 and the second polymer coating layer 220 can easily achieve the elastic modulus value described later. can be achieved Since the elastic moduli of the first polymeric coating layer 120 and the second polymeric coating layer 220 are sufficiently large, the object S, even after heat and pressure are applied to the object (S), the first polymeric coating layer 120 and the first polymeric coating layer 220 2 can be easily separated from them by the restoring force of the polymer coating layer 220 . In addition, since the hardness of each of the first polymeric coating layer 120 and the second polymeric coating layer 220 is sufficiently large, while applying heat and pressure to the object (S), the object (S) is the first polymeric coating layer 120 and Even if it is pressed against the second polymeric coating layer 220, it can be easily separated due to its small adhesive force.

The weight average molecular weight Mw of the polyether ether ketone may be 25,000 g / mol to 50,000 g / mol, and when it is in the above range, it can be easily coated on the heating plate of the hot pressing device, and the object (S) is the first polymer Even if pressed against the coating layer 120 and the second polymeric coating layer 220, the adhesion is small and can be easily separated.

Specifically, the polyether ether ketone may be represented by Formula 1 below.

[Formula 1]

In Formula 1, n is an integer from 10 to 500.

Representative products containing the polyether ether ketone include VICOTE® coating materials, and preferably, the VICOTE 700 series can be used.

The elastic moduli of the first polymer coating layer 120 and the second polymer coating layer 220 may be independently greater than or equal to 3 Gpa. Here, the elastic modulus means a tensile modulus.

When the modulus of elasticity of the first polymeric coating layer 120 and the second polymeric coating layer 220 is 3 Gpa or more independently of each other, even after heat and pressure are applied to the object S by the hot pressing device, it can be easily separated by restoring force. , The phenomenon that the object (S) is attached to the upper plate 100 and the lower plate 200 can be significantly reduced.

If the modulus of elasticity of the first polymer coating layer 120 and the second polymer coating layer 220 is less than 3 Gpa, after the object S is pressed, the first polymer coating layer 120 and the second polymer coating layer ( 220) may not have a sufficiently high modulus of elasticity, so that the object (S) may adhere to each polymer coating layer (120, 220).

Specifically, the elastic modulus of the first polymer coating layer 120 and the second polymer coating layer 220 may be independently 3 Gpa to 5 Gpa, and more specifically, 3 Gpa to 4 Gpa. When the elastic moduli of the first polymer coating layer 120 and the second polymer coating layer 220 satisfy the above numerical range, the upper plate 100 and the lower plate 200 approach each other to apply heat and pressure to the object S When the first polymeric coating layer 120 and the second polymeric coating layer 220 come into contact with the object (S) and are pressed, the resilience is high, so that the attachment of the object (S) can be prevented.

Shore hardness of the first polymeric coating layer 120 and the second polymeric coating layer 220 may be independently D70 to D90, specifically D80 to D90, and more specifically D85 to D90 days. can When the shore hardness of the first polymeric coating layer 120 and the second polymeric coating layer 220 respectively satisfy the above numerical range, the first polymeric coating layer 120 and the second polymeric coating layer 220 are sufficiently hard, and thus hot pressing After applying heat and pressure to the object (S) by the device 10, the object (S) can be prevented from being pressed and adhered to the first polymeric coating layer 120 and the second polymeric coating layer 220.

The thickness of the first polymeric coating layer 120 (t ₁₂₀ ) and the thickness of the second polymeric coating layer 220 (t ₂₂₀ ) may be independently 30 μm to 50 μm, specifically 35 μm to 45 μm. . When the respective thicknesses (t ₁₂₀ , t ₂₂₀ ) of the first polymer coating layer 120 and the second polymer coating layer 220 satisfy the numerical range, the first polymer coating layer 120 and the second polymer coating layer 220 Since each thickness (t ₁₂₀ , t ₂₂₀ ) is sufficiently thick compared to the thickness (t ₁₁₀ ) of the first heating plate 110 and the thickness (t 120) of the second heating plate 120, the first heating plate ₁₁₀ and the object (S) or the phenomenon that the second heating plate 120 and the object (S) are energized with each other can be prevented.

The surface roughness (Rmax) of the first polymer coating layer 120 and the second polymer coating layer 220 may independently of each other be 10 μm to 50 μm, specifically 15 μm to 45 μm, and more specifically It may be 20 μm to 40 μm. The surface roughness (Rmax) of the first polymer coating layer 120 is defined as the difference between the maximum height and the minimum height of the surface of the first polymer coating layer 120, and the surface roughness (Rmax) of the second polymer coating layer 220 is 2 It is defined as the difference between the maximum height and the minimum height of the surface of the polymer coating layer 220 . When the surface roughness of the first polymeric coating layer 120 and the second polymeric coating layer 220 satisfies the numerical range, the surface of the first polymeric coating layer 120 and the second polymeric coating layer 220, respectively, is in contact with the object (S). Because it is sufficiently flat, it is possible to prevent defective stamping that may occur on the object (S).

The surface roughness may be measured using a dial gauge.

The first polymer coating layer and the second polymer coating layer may be prepared by spraying or applying a coating composition containing polyether ether ketone and a solvent to a first heating plate and/or a second heating plate, and drying the coating composition.

The coating composition may be prepared by further including a binder together with the polyether ether ketone and the solvent. The binder is not particularly limited as long as it can be applied in the field, and for example, polyvinylidene fluoride, polyvinyl alcohol, styrene butadiene rubber, polyethylene oxide, Boxyl methyl cellulose, cellulose acetate, cellulose acetate butylate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpoly Cyanoethyl polyvinylalcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, polymethylmethacrylate, polybutylacrylate, polyacrylic At least one selected from the group consisting of polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, ethylene-co-vinyl acetate, and polyarylate species may be included.

3 and 4 are diagrams schematically illustrating a hot pressing apparatus according to another embodiment of the present invention. Specifically, FIG. 3 is a perspective view schematically illustrating a hot pressing device according to another embodiment of the present invention, and FIG. 4 schematically shows side cross-sections of upper and lower plates of the hot pressing device according to another embodiment of the present invention. It is an illustrated drawing.

The hot pressing device 10 of FIGS. 3 and 4 has been described with reference to FIGS. 1 and 2 except that the first metal oxide layer 140 and the second metal oxide layer 240 are further included. (10) can be the same.

3 and 4, the upper plate 100 may further include a first metal oxide layer 140 disposed between the first heating plate 110 and the first polymer coating layer 120, The lower plate 200 may further include a second metal oxide layer 240 disposed between the second heating plate 210 and the second polymer coating layer 220 .

In the case of the upper plate 100 as an example, the first metal oxide layer 140 may be disposed between the first heating plate 110 and the first polymer coating layer 120, and the first metal oxide layer 140 Since silver has insulating properties, it is possible to further prevent current between the object S and the first heating plate 110 . Similarly in the case of the lower plate 200, the second metal oxide layer 240 may be disposed between the second heating plate 210 and the second polymer coating layer 220, and the second metal oxide layer 240 Since it has insulating properties, it is possible to further prevent energization between the object S and the second heating plate 210 .

The first metal oxide layer 140 may include an oxide of a metal included in the first heating plate 110 .

Specifically, the first metal oxide layer and the second metal oxide layer may independently include one or more selected from the group consisting of aluminum oxide, iron oxide, copper oxide, and zinc oxide, preferably the first Aluminum oxide may be included in terms of providing proper insulation between the heating plate 110 and the second heating plate 210 and the object S.

The first metal oxide layer 140 may be formed by hard anodizing the surface of the first heating plate 110 . That is, the first metal oxide layer 140 may be formed by oxidizing the surface of the first heating plate 110 . Since the first metal oxide layer 140 is formed by the hard anodizing, the first polymer coating layer 120 can be better bonded to the upper plate 100, and the first heating plate 110 and the object ( S) insulation can be further secured between them. The second metal oxide layer 240 may be applied in the same manner as the case of the first metal oxide layer 140 .

The thicknesses (t 140 and t 240 ) of the first metal oxide layer ₁₄₀ and the second metal oxide layer ₂₄₀ may be independently 10 μm to 50 μm, specifically 15 μm to 45 μm, , More specifically, it may be 20 μm to 40 μm. When the thicknesses (t ₁₄₀ , t ₂₄₀ ) of the first metal oxide layer 140 and the second metal oxide layer 240 satisfy the numerical range, the first metal oxide layer 140 and the second metal oxide layer ( 240) is sufficiently thick, it is possible to secure insulation between the first heating plate 110 and the second heating plate 210 and the object S, and accordingly, the first heating plate 110 and the second heating plate It is possible to prevent a phenomenon in which 210 is energized with the object (S).

5 is a side cross-sectional view of an upper plate of a hot pressing apparatus according to another embodiment of the present invention.

The hot pressing device may further include a heating means 150 for transferring heat to each of the first heating plate 110 and the second heating plate 210 . Although FIG. 5 shows the first heating plate 110 of the upper plate 100 to include three heating means 150 as an example, it is not necessarily limited thereto, and the first heating plate 110 is an object (S). ) It may include an appropriate number of heating means 150 in order to apply an appropriate level of heat to the. The above description may also be applied to the second heating plate (not shown) in the same manner.

Referring to FIG. 5 , the heating means 150 may be inserted and disposed inside the first heating plate 100 . The heating means 150 may be spaced apart from each other by a certain distance.

The heating means 150 may be extended in length in the longitudinal direction (D-D') of the upper plate 100, and the heating means 150 heats the object S through the first polymeric coating layer 120. can deliver. Specifically, the heating unit 150 may be a heater rod.

Meanwhile, the hot pressing device 10 may pressurize the secondary battery. Specifically, the secondary battery may be a pouch-type secondary battery.

The hot pressing device 10 according to the present invention may be used during a manufacturing process of a pouch type secondary battery. Specifically, the manufacturing process of the pouch-type secondary battery includes inserting an electrode assembly and an electrolyte into a pouch; activating the electrode assembly; a degassing step of removing gas in the pouch; sealing the pouch; and a hot press step of applying heat and pressure to the pouch.

The hot pressing device 10 may be used in a hot pressing step of applying heat and pressure to the pouch during the manufacturing process of the pouch type secondary battery. As the hot pressing device 10 applies heat and pressure to the pouch, the thickness of the pouch can be appropriately adjusted and surface defects of the pouch can be improved.

In addition, according to the present invention, since the upper plate 100 and the lower plate 200 of the hot pressing device 10 include the first polymer coating layer 120 and the second polymer coating layer 220, respectively, the hot pressing step In this case, the attachment of the pouch-type secondary battery to the upper plate 100 or the lower plate 200 can be prevented, and thus defects of the pouch-type secondary battery can be improved.

The pouch-type secondary battery may include a general-purpose configuration in this technical field.

Specifically, the pouch-type secondary battery may include a pouch-type battery case, an electrode assembly accommodated in the pouch-type battery case and including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and an electrolyte.

The pouch-type battery case includes an inner layer, a metal layer, and an outer layer, and the inner layer and the outer layer may each independently be a polymer resin layer, and the metal layer may include, for example, a metal such as aluminum. .

The electrode assembly includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and the electrode assembly may be, for example, a laminate in which the positive electrode, the separator, and the negative electrode are alternately stacked, and the positive electrode , It may be a jelly-roll type electrode assembly in which the separator and the negative electrode are alternately stacked and wound.

The electrolyte may serve to assist ion movement between the positive electrode and the negative electrode, and the electrolyte may include a material known in the art.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

Example

A hot pressing device (a joint product of GPI, YTS, and Daejin Machinery) including a first heating plate and a second heating plate was prepared. The first heating plate and the second heating plate were placed opposite to each other in the hot pressing device. The first heating plate and the second heating plate are connected to the lifting and lowering driving means through a first connecting member and a second connecting member, respectively. The first heating plate and the second heating plate are installed to be movable upward or downward by the lifting and lowering driving means. The first heating plate and the second heating plate were made of aluminum and had a length of 700 mm, a width of 300 mm, and a thickness of 25 mm. In addition, heater rods are installed inside the first heating plate and the second heating plate to transfer heat to an object (pouch-type secondary battery).

In the hot pressing device, the first heating plate and the second heating plate were separated, and the surface of each of the first heating plate and the second heating plate was hard anodized. Accordingly, an aluminum oxide (Al 2 O ₃ ) film was formed as a first metal oxide layer and a second metal oxide layer on the surfaces of the first heating plate and the second heating plate, respectively, and the thickness of the aluminum oxide ( _{Al 2 O 3} ) film was respectively It was 30 μm.

Then, a coating composition including a polyetheretherketone polymer (VICOTE® 700 series), a binder, and a solvent was prepared to form the first polymer coating layer and the second polymer coating layer, and the first heating plate and the second heating plate were prepared. The coating composition was sprayed on the surface of each formed aluminum oxide film and dried at 350° C. for 10 minutes to form a first polymer coating layer and a second polymer coating layer. The thickness of each of the first polymer coating layer and the second polymer coating layer was 40 μm.

Then, the first polymer coating layer and the second polymer coating layer were polished. The first polymer coating layer and the second polymer coating layer each had an elastic modulus of 3.5 Gpa, a thickness of 40 μm, a shore hardness of D85, and a surface roughness (Rmax) of 30 μm. The elastic modulus and shore hardness values referred to the values described in the VICOTE® product, and the surface roughness (Rmax) was measured using a dial gauge device.

A structure (upper plate) in which a first heating plate, a first metal oxide layer, and a first polymer coating layer are sequentially stacked is installed on the upper side of the hot pressing device, and a second heating plate, a second metal oxide layer, and a second polymer coating layer are sequentially stacked. A hot pressing device according to the present invention was manufactured by installing a structure (lower plate) in which coating layers were sequentially stacked on the lower side of the hot pressing device. In the hot pressing device, the first polymer coating layer and the second polymer coating layer are disposed facing each other.

comparative example

A hot pressing device was manufactured in the same manner as in Example, except that a Teflon coating layer was used as the first polymer coating layer and the second polymer coating layer, respectively.

The first Teflon coating layer and the second Teflon coating layer each had an elastic modulus of 0.8 Gpa, a thickness of 40 μm, a shore hardness of D50, and a surface roughness (Rmax) of 30 μm.

Experimental Example 1 - Evaluation of plate attachment rate of pouch-type secondary battery

<Manufacture of pouch type secondary battery>

A pouch-type secondary battery in which an electrode assembly including a positive electrode, a negative electrode, and a separator was accommodated in a pouch-type battery case and an electrolyte was injected was manufactured.

<Evaluation of plate adhesion rate>

The adhesion rate when the prepared pouch-type secondary battery was pressed using the hot pressing device according to Comparative Example was evaluated. The pressure applied by the hot pressing device to the pouch-type secondary battery was 2 ton, the temperature applied to the pouch-type secondary battery was 80° C., and the time for applying heat and pressure was set to 5 seconds. The hot press step was performed a total of 300 times for 300 pouch-type secondary batteries.

In the hot pressing apparatus of Comparative Example, after hot pressing was performed, whether or not the pouch type secondary battery had a defect occurrence rate and defect types are shown in Table 1 below.

category number of attachments ratio(%) total(%) error (One) 71 23.7 47.4 (2) 51 17.0 (3) 20 6.7 normal 158 52.6 52.6 Sum 300 100 100 <bad type>
(1): Attachment of pouch type secondary battery and upper and lower plates
(2): Occurrence of fall due to partial attachment of pouch type secondary battery and upper plate
(3): Occurrence of fall due to complete attachment of the pouch-type secondary battery and the upper plate

The adhesion rate when the pouch type secondary battery was pressed using the hot pressing device according to the example was evaluated. The pressure applied by the hot pressing device to the pouch-type secondary battery was 2 ton, and the temperature applied to the pouch-type secondary battery was 80°C. A pouch-type secondary battery was manufactured by accommodating an electrode assembly including a positive electrode, a negative electrode, and a separator in a pouch-type battery case.

A total of 1,000 hot press steps were performed.

As a result of the experiment, when heat and pressure were applied to the pouch-type secondary battery using the hot pressing device according to the embodiment, the number of times the pouch-type secondary battery was attached was evaluated as 0 times.

Accordingly, when the upper plate and the lower plate of the hot pressing device include the first polymer coating layer and the second polymer coating layer, respectively, the problem of attachment of the pouch-type secondary battery to the upper plate or the lower plate is significantly improved. Confirmed.

Experimental Example 2 - Evaluation of plate attachment rate of pouch-type secondary battery under extreme conditions

Heat and pressure were applied to the pouch-type secondary battery using the hot pressing device according to the embodiment. The pressure applied by the hot pressing device to the pouch-type secondary battery was 4 ton, the temperature applied to the pouch-type secondary battery was 100° C., and the time for applying heat and pressure was set to 10 seconds.

As a result of the experiment, the number of times the pouch-type secondary battery was attached to the hot pressing device was evaluated as 0 even under the above experimental conditions. Accordingly, when the upper plate and the lower plate of the hot pressing device include the first polymer coating layer and the second polymer coating layer, respectively, the problem of attachment of the pouch-type secondary battery to the upper plate or the lower plate is significantly improved. Confirmed.

10: hot pressing device
100: upper plate
110: first heating plate
120: first polymer coating layer
130: first connecting member
140: first metal oxide layer
150: first heating means
200: lower plate
210: second heating plate
220: second polymer coating layer
230: second connecting member
240: second metal oxide layer
S: object

Claims (15)

an upper plate including a first heating plate and a first polymeric coating layer disposed on one surface of the first heating plate; and
a lower plate facing and spaced apart from the upper plate and including a second heating plate and a second polymer coating layer disposed on one side of the second heating plate;
including,
At least one of the upper plate and the lower plate is movable,
The first polymer coating layer and the second polymer coating layer each contain polyether ether ketone, hot pressing device.
According to claim 1,
The elastic moduli of the first polymer coating layer and the second polymer coating layer are independently of each other 3 Gpa or more, the hot pressing device.
According to claim 1,
The first polymer coating layer and the elastic modulus of the second polymer coating layer are independently of each other 3 Gpa to 5 Gpa, the hot pressing device.
According to claim 1,
The first polymer coating layer and the second polymer coating layer are disposed facing each other, the hot pressing device.
According to claim 1,
The thickness of the first polymer coating layer and the second polymer coating layer is independently from each other 30 ㎛ to 50 ㎛, the hot pressing device.
According to claim 1,
Shore hardness of the first polymer coating layer and the second polymer coating layer are independently D70 to D90, hot pressing device.
According to claim 1,
The surface roughness (Rmax) of the first polymer coating layer and the second polymer coating layer is 10 μm to 50 μm independently of each other, the hot pressing device.
According to claim 1,
The hot pressing apparatus, wherein the first heating plate and the second heating plate have a thickness of 10 mm to 40 mm independently of each other.
According to claim 1,
The first heating plate and the second heating plate independently include at least one selected from the group consisting of aluminum, iron, copper, and zinc.
According to claim 1,
The upper plate further includes a first metal oxide layer disposed between the first heating plate and the first polymer coating layer,
The hot pressing apparatus of claim 1, wherein the lower plate further comprises a second metal oxide layer disposed between the second heating plate and the second polymer coating layer.
According to claim 10,
Wherein the first metal oxide layer and the second metal oxide layer independently include at least one selected from the group consisting of aluminum oxide, iron oxide, copper oxide, and zinc oxide.
According to claim 10,
The hot pressing apparatus, wherein the first metal oxide layer and the second metal oxide layer have a thickness of 10 μm to 50 μm independently of each other.
According to claim 1,
and a heating means for transmitting heat to each of the first heating plate and the second heating plate.
According to claim 1,
The hot pressing device pressurizes the secondary battery.
According to claim 14,
The secondary battery is a pouch-type secondary battery, hot pressing device.

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