Battery case sealing device and battery case sealing method using the same

Abstract

The present invention relates to a battery case sealing device and a battery case sealing method using the same, and more particularly to a battery case sealing device and a battery case sealing method using the same for sealing pouch-type secondary batteries. The present invention provides a battery case sealing device including a primary sealing unit that applies pressure to a battery case containing an electrode assembly to seal it, a pair of primary heating units that are located in front of and behind the primary sealing unit, respectively, to heat the battery case, and a transport unit that transports the battery case.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0183210 filed December 20, 2021 and Korean Patent Application No. 10-2022-0179477 filed December 20, 2022, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery case sealing device and a battery case sealing method using the same, and more particularly to a battery case sealing device and a battery case sealing method using the same that seals pouch-type battery cases. [Background technology]

[0003] Batteries generate electrical energy through physical or chemical reactions of materials and supply power to the outside world. They are used in living environments where various electrical and electronic devices are present and AC power cannot be obtained from the building, or DC power is required.

[0004] Among these batteries, primary and secondary batteries, which are chemical batteries that utilize chemical reactions, are commonly used. Primary batteries, commonly known as dry batteries, are consumable batteries. Secondary batteries are rechargeable batteries made using materials that can undergo a redox process between current and a substance multiple times. When a reduction reaction of the material occurs due to current, the power source is charged, and when an oxidation reaction of the material occurs, the power source is discharged. Electricity is generated by repeating this charge-discharge cycle.

[0005] In recent years, pouch-type secondary batteries have been attracting attention in the market due to their small volume and high design flexibility. Specifically, a pouch-type secondary battery is a secondary battery in which an electrode assembly is housed in a pouch-type battery case. Here, the battery case generally has a multilayer structure in which an inner resin layer, a metal layer, and an outer resin layer are stacked in this order from the inside to the outside.

[0006] The battery case has a sealed structure in which an inner resin layer is heat-sealed at least at a portion of the outer periphery to prevent the inner electrode assembly from being exposed to external moisture and air.

[0007] Meanwhile, in recent years, as the thickness of the electrode lead has changed for rapid charging of the secondary battery and the thickness of the battery case has increased for improving the energy density of the secondary battery, there has been a demand to increase the amount of heat and pressure required to seal the battery case.

[0008] However, in the past, in a sealing device having one pressure press, when the heating temperature of the pressure press was increased, there was a problem that the surface of the battery case would melt or wrinkles would occur due to heat, and when the pressure applied to the battery case by the pressure press was increased, there was a problem that part of the internal resin layer would leak into or out of the battery case.

[0009] Furthermore, if the heat and pressure conditions of the sealing device are reduced, it goes without saying that the sealing quality will deteriorate, and there will be a problem that heat loss will occur, particularly in the electrode leads, which have a low rate of temperature rise, and the sealing quality of the battery case will deteriorate significantly at the positions corresponding to the electrode leads.

[0010] Therefore, with conventional sealing devices, it is currently very difficult to select heat and pressure conditions that can ensure the sealing quality of thick battery cases. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to solve the above problems, and an object of the present invention is to provide a battery case sealing device and a battery case sealing method using the same that can ensure sealing quality even when sealing a thick battery case. [Means for solving the problem]

[0012] The present invention provides a battery case sealing device including a primary sealing unit that applies pressure to seal a battery case containing an electrode assembly, a pair of primary heating units that are positioned in front of and behind the primary sealing unit and heat the battery case, and a transfer unit that transfers the battery case.

[0013] The primary heating unit may be arranged to extend along a direction in which the battery case is transferred.

[0014] The primary heating unit may heat the battery case in a non-contact manner.

[0015] The battery case may have electrode leads protruding from at least one end thereof and electrically connected to the electrode assembly, and the primary seal unit may pressurize and seal an area of ​​the battery case corresponding to the electrode leads.

[0016] Meanwhile, the battery case sealing device according to the present invention may further include a secondary sealing unit located behind the primary sealing unit and the primary heating unit, for pressurizing and sealing the battery case.

[0017] The battery case sealing device according to the present invention may further include a secondary heating unit positioned behind the secondary sealing unit and configured to heat the battery case.

[0018] The battery case sealing device according to the present invention may further include a transfer unit that transfers the battery case, and the secondary heating unit may extend along a transfer direction of the battery case.

[0019] The secondary heating unit may heat the battery case in a non-contact manner.

[0020] The area over which the secondary seal unit applies pressure to the battery case may be larger than the area over which the primary seal unit applies pressure to the battery case.

[0021] Meanwhile, the present invention provides a method for sealing a battery case, including: a first heating step of heating a battery case containing an electrode assembly; a first sealing step of pressurizing and sealing the battery case after the first heating step; and a second heating step of heating the battery case after the first sealing step.

[0022] In at least one of the first heating step and the second heating step, the battery case may be heated along a direction in which the battery case is transferred.

[0023] In at least one of the first heating step and the second heating step, the battery case may be heated in a non-contact manner.

[0024] In the first sealing step, sealing may be performed at a position corresponding to an electrode lead protruding from at least one end of the electrode assembly.

[0025] Meanwhile, the method for sealing a battery case according to the present invention may further include a second sealing step of pressurizing and sealing the battery case after performing the first sealing step and the second heating step.

[0026] Furthermore, the battery case sealing method according to the present invention may further include a post-heating step of heating the battery case after the second sealing step. [Effects of the Invention]

[0027] According to a preferred embodiment of the present invention, a pair of primary heating units are provided in front and behind the primary sealing unit, thereby ensuring sufficient heat required to seal the battery case, preventing sudden temperature changes in the battery case, preventing heat loss during transport of the battery case, and improving the appearance of the battery case and the sealing quality of the battery case.

[0028] In addition, by including the secondary sealing unit and the primary sealing unit, the sealing area of ​​the battery case can be sealed by applying pressure multiple times, which has the advantage of ensuring sealing quality even if the thickness of the battery case increases.

[0029] Furthermore, the primary sealing unit, secondary sealing unit, primary heating unit, and secondary heating unit can be used to variably select the heat quantity and pressure conditions for sealing the battery case, which has the advantage of being able to quickly and easily seal even thick battery cases. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 2 is a front view of the secondary battery. [Figure 2] 2A to 2C are schematic diagrams sequentially showing the steps of manufacturing the secondary battery of FIG. 1. [Figure 3] FIG. 1 is a conceptual diagram illustrating a sealing device for a battery case according to a first embodiment of the present invention. [Figure 4] 3 is a side view showing in more detail the state of the primary seal unit in the sealing device for the battery case of FIG. 2. FIG. [Figure 5] 10 is a flowchart sequentially showing a method for sealing a battery case according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily understand the preferred embodiments of the present invention. However, the present invention can be realized in various different forms and is not limited to the following embodiments.

[0032] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the explanation or related known technologies that may obscure the gist of the present invention will be omitted, and when referring to components in each drawing in this specification, the same or similar reference symbols will be used for the same or similar components throughout the specification.

[0033] Furthermore, the terms and words used in this specification and claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, based on the principle that an inventor can appropriately define the concept of a term in order to explain his or her invention in the best possible way.

[0034] Battery case sealing device 100 The present invention provides a battery case sealing device 100 including a primary sealing unit 110 that applies pressure to and seals a battery case 12 containing an electrode assembly 11, a pair of primary heating units 120 that are positioned in front of and behind the primary sealing unit 110 and heat the battery case 12, and a transfer unit 130 that transfers the battery case 12.

[0035] Before describing the configuration of the battery case sealing device 100, a battery case 12 that is sealed by the battery case sealing device 100 and that constitutes the secondary battery 10 together with the electrode assembly 11 will be described.

[0036] 1, the battery case 12 is configured to house the electrode assembly 11 and can have various configurations. It should be noted that the electrode assembly 11 is configured to be housed inside the battery case 12 and is indicated by a dotted line.

[0037] Here, the electrode assembly 11 is configured by applying an electrode active material onto an electrode current collector to form a positive electrode and a negative electrode, with a separator interposed therebetween, and may have a wound structure, a stack structure, a stack / folding structure, etc. The electrode assembly 11 may be housed in a battery case 12 together with an electrolyte.

[0038] Specifically, the battery case 12 may be formed with a receiving portion 12' for receiving the electrode assembly 11, and may have an electrode lead 13 protruding from at least one end thereof so as to be electrically connected to the electrode assembly 11. Here, the receiving portion 12' may be understood as a region formed in a recessed shape in at least one region of the battery case 12 so as to receive the electrode assembly 11.

[0039] More specifically, the battery case 12 is manufactured by folding the battery case 12 containing the electrode assembly 11 in an unfolded state as shown in FIG. 2(a) in half along the length direction of the battery case 12 (the y direction in FIG. 2(b)) as shown in FIG. 2(b).

[0040] The battery case 12 may have a sealed structure to prevent the electrode assembly 11 housed in the housing portion 12' from being damaged by exposure to external moisture and air.

[0041] Specifically, the battery case 12 may include a sealing region 12a formed by bonding a portion of the outer periphery of the battery case 12 to one another. Here, the sealing region 12a can be understood as a region where the outer periphery of the battery case 12 is bonded to one another by heating and / or pressurizing the battery case 12 when the battery case 12 is folded or when two or more battery cases 12 are provided so as to overlap each other to form a region where the battery cases 12 abut against each other.

[0042] More specifically, the sealing area 12a may include a first sealing area 12aa corresponding to the electrode lead 13 in the sealing area 12a formed in the length direction (y direction in Figure 1) of the battery case 12, a second sealing area 12ab which is the area of ​​the sealing area 12a formed in the length direction (y direction in Figure 1) of the battery case 12 excluding the first sealing area 12aa, and a third sealing area 12ac formed in the width direction (x direction in Figure 1) of the battery case 12.

[0043] Here, the first sealing area 12aa is an area where the electrode lead 13 abuts against the battery case 12, and can be understood as an area where sealing between the electrode lead 13 and the battery case 12 is performed.

[0044] The sealing area 12a may be formed by sealing the first sealing area 12aa and the second sealing area 12ab as shown in Fig. 2(c), and then sealing the third sealing area 12ac as shown in Fig. 2(d). Here, after sealing the first sealing area 12aa and the second sealing area 12ab and before sealing the third sealing area 12ac, an electrolyte may be poured into the storage section 12'.

[0045] Meanwhile, the battery case 12 may be transported by a transport unit 130. Specifically, the battery case 12 may be transported by the transport unit 130 with the electrode assembly 11 housed therein. The transport unit 130 may be configured with a conveyor belt or a plurality of rollers. Here, as shown in FIG. 3 , the battery case 12 may be transported through a primary sealing unit 110, a primary heating unit 120, a secondary sealing unit 140, and a secondary heating unit 150, which will be described later.

[0046] Here, the primary sealing unit 110 is configured to pressurize and seal the battery case 12 and can have various configurations. The primary sealing unit 110 can pressurize and seal an area of ​​the battery case corresponding to an electrode lead.

[0047] Specifically, the primary sealing unit 110 is positioned above or below the battery case 12 transferred by the transfer unit 130 and can seal the sealing area 12a by applying pressure to at least a portion of the outer periphery of the battery case 12. To this end, the primary sealing unit 110 may be provided so as to be movable up and down toward the battery case 12. Here, it goes without saying that the primary sealing unit 110 can also seal the sealing area 12a by simultaneously applying pressure and heat to at least a portion of the outer periphery of the battery case 12.

[0048] More specifically, the primary sealing unit 110 may pressurize and seal at least one of the first sealing area 12aa, the second sealing area 12ab, and the third sealing area 12ac. That is, if each sealing area is formed in a stepped shape, the primary sealing unit 110 may have a stepped shape corresponding to the shape of each sealing area.

[0049] Here, in the present invention, if a secondary sealing unit 140 described later is further provided, the primary sealing unit 110 may perform sealing only in the first sealing area 12aa located in the battery case 12 corresponding to the electrode lead 13.

[0050] That is, the primary sealing unit 110 may perform sealing only in the first sealing area 12aa, taking into consideration that if sealing is performed multiple times in the same area, a sealing step may occur, and that the electrode lead 13, which has a lower temperature rise rate than the battery case 12, loses the heat required for sealing, resulting in a decrease in sealing quality at the position corresponding to the electrode lead 13.

[0051] Meanwhile, a pair of primary heating units 120 may be provided in front and behind the primary sealing unit 110. Hereinafter, for convenience of explanation, the direction in which the battery case 12 is transferred on the transfer part 130 will be referred to as the rear, and the opposite direction of the rear will be referred to as the front.

[0052] Specifically, as shown in FIG. 2, the primary heating units 120 are positioned in front of and behind the primary sealing unit 110 to heat the battery case 12, and various configurations are possible.

[0053] For example, the primary heating unit 120 may be installed to extend along the direction in which the battery case 12 is transferred in order to minimize heat loss from the battery case 12 that may occur due to the transfer of the battery case 12 .

[0054] Specifically, the primary heating unit 120 may extend along the transfer direction of the battery case 12 so as to continuously supply heat to the battery case 12. To this end, the primary heating unit 120 may include a plurality of heating blocks (not shown) arranged along the transfer direction of the battery case 12. As a result, the primary heating unit 120 can minimize heat loss that may occur in the battery case 12 during transfer of the battery case 12.

[0055] In addition, the primary heating unit 120 can heat the battery case 12 in a non-contact manner.

[0056] Specifically, the primary heating unit 120 includes a non-contact heating means such as a high-frequency heating means, an infrared heating means, or an ultraviolet heating means, and can heat the battery case 12 in a non-contact manner while being spaced a predetermined distance from the battery case 12. As a result, the primary heating unit 120 heats the battery case 12 while transferring the battery case 12, thereby minimizing heat loss from the battery case 12 and enabling continuous processing.

[0057] The primary heating unit 120 continues to form a high-temperature atmosphere in the battery case 12 before and after the battery case 12 is sealed by the primary sealing unit 110, thereby ensuring sufficient sealing quality without applying excessive pressure during sealing.

[0058] Here, the high temperature can be understood as a temperature above room temperature. Here, room temperature refers to the temperature range known in the art as "room temperature" or normal temperature. Generally, it is understood to be a temperature at which humans can feel comfortable, usually around 15°C to 20°C. Therefore, the temperature above room temperature is a temperature of 20°C or higher, and more specifically, when the material of the internal resin layer of the sealing area 12a is polypropylene resin, it can be understood to be 160°C to 190°C.

[0059] Specifically, of the pair of primary heating units 120, the primary heating unit 120 located in front of the primary sealing unit 110 can provide the battery case 12 with the heat required for sealing before sealing the battery case 12. This allows the internal resin layer of the sealing region 12a to be sufficiently melted even when sealing a thick battery case 12, thereby helping to improve sealing quality. That is, when a sealing process is performed in a high-temperature and high-pressure environment after heating by the primary sealing unit 110, the internal resin layer that has not yet melted may be pressurized, resulting in inaccurate sealing. However, this problem can be prevented by preheating the primary heating unit 120 located in front of the battery case 12.

[0060] Here, the thickness of the battery case 12 can be understood to be 180 μm to 190 μm, but it should be noted that the thickness of the battery case 12 is not limited to this.

[0061] Furthermore, of the pair of primary heating units 120, the primary heating unit 120 located behind the primary sealing unit 110 prevents a sudden change in the temperature of the battery case 12 after sealing the battery case 12, thereby minimizing the formation of bubbles in the internal resin layer. Specifically, if the temperature of the battery case 12 changes suddenly after the sealing process, the resin layer may solidify quickly without the air present inside the resin layer being released, resulting in the formation of bubbles inside the resin layer. That is, the primary heating unit 120 located behind maintains a high-temperature environment so that the air inside the resin layer is gradually released, thereby minimizing the formation of bubbles in the internal resin layer.

[0062] Furthermore, in the present invention, if a secondary sealing unit 140 is further provided and sealing is performed multiple times, the primary heating unit 120 can sufficiently melt the internal resin layer of the sealing area 12a before sealing by the secondary sealing unit 140, which can of course help improve the sealing quality.

[0063] Meanwhile, the sealing device for the battery case 12 according to the present invention may further include a secondary sealing unit 140 located behind the primary sealing unit 110 and the primary heating unit 120 to pressurize and seal the battery case 12.

[0064] Specifically, the secondary seal unit 140 is configured to pressurize and seal at least a portion of the outer periphery of the battery case 12, and various configurations are possible.

[0065] Specifically, the secondary sealing unit 140 may be positioned above or below the battery case 12 transferred by the transfer unit 130 to pressurize and seal at least a portion of the outer periphery of the battery case 12. To this end, the secondary sealing unit 140 may be provided to be movable up and down toward the battery case 12. Here, it goes without saying that the secondary sealing unit 140 may seal the sealing area 12a by simultaneously pressing and heating at least a portion of the outer periphery of the battery case 12.

[0066] Meanwhile, the secondary sealing unit 140 can seal at least one of the first sealing area 12aa, the second sealing area 12ab, and the third sealing area 12ac.

[0067] Here, the pressing area where the secondary sealing unit 140 presses the battery case 12 may be larger than the pressing area where the primary sealing unit 110 presses the battery case 12 .

[0068] Specifically, the secondary sealing unit 140 can apply pressure to and seal a larger area than the primary sealing unit 110, taking into consideration that the secondary sealing unit 140 must seal areas not sealed by the primary sealing unit 110 to form a sealed structure for the battery case 12, and that additional sealing may be performed even in areas sealed by the primary sealing unit 110 to supplement the sealing quality.

[0069] For example, when the primary sealing unit 110 pressurizes the first sealing area 12aa to seal it, the secondary sealing unit 140 can pressurize and seal at least one of the second sealing area 12ab and the third sealing area 12ac along with the first sealing area 12aa.

[0070] Meanwhile, the present invention may further include a secondary heating unit 150 positioned behind the secondary sealing unit 140 to heat the battery case 12 .

[0071] Specifically, the secondary heating unit 150 is configured to heat the battery case 12, and various configurations are possible.

[0072] For example, the secondary heating unit 150 may be installed to extend along the direction in which the battery case 12 is transferred in order to minimize heat loss from the battery case 12 that may occur due to the transfer of the battery case 12 .

[0073] Specifically, the secondary heating unit 150 may be installed to extend along the transfer direction of the battery case 12 so as to continuously supply heat to the battery case 12. To this end, the secondary heating unit 150 may include a plurality of heating blocks (not shown) arranged along the transfer direction of the battery case 12. As a result, the secondary heating unit 150 can minimize heat loss that may occur in the battery case 12 during transfer of the battery case 12.

[0074] In addition, the secondary heating unit 150 can heat the battery case 12 in a non-contact manner.

[0075] Specifically, the secondary heating unit 150 may heat the battery case 12 in a non-contact manner using a non-contact heating means such as a high frequency heating means, an infrared heating means, or an ultraviolet heating means at a predetermined distance from the battery case 12. As a result, the secondary heating unit 150 may heat the battery case 12 while transferring the battery case 12, thereby minimizing heat loss from the battery case 12 and enabling continuous processing.

[0076] The secondary heating unit 150 prevents the temperature of the battery case 12 from changing suddenly after sealing the battery case 12, thereby minimizing the generation of bubbles in the inner resin layer.

[0077] Meanwhile, the primary seal unit 110 may have various structures.

[0078] The structure of the primary seal unit 110 will be described in more detail below with reference to Fig. 4. However, it goes without saying that the structure of the primary seal unit 110 can also be applied to the secondary seal unit 140, and for the sake of convenience, only the structure of the primary seal unit 110 will be described below.

[0079] For example, as shown in FIG. 4, the primary seal unit 110 may include the main body part 111 and a press part 112 coupled to the main body part 111 to pressurize the battery case 12.

[0080] Here, the main body 111 may have a structure in which a plurality of blocks are stacked and connected to each other with bolts. Here, at least one of the blocks is connected to an external electric device and can generate a temperature above room temperature. Here, the meaning of room temperature is as described above.

[0081] The press part 112 is configured to pressurize the battery case 12 and can have various configurations.

[0082] For example, the pressing portion 112 may protrude from one surface of the main body portion 111 toward the battery case 12 and pressurize the sealing area 12a. The sealing area 12a may include at least one of the first sealing area 12aa, the second sealing area 12ab, and the third sealing area 12ac. The pressing portion 112 may have various shapes. Needless to say, the pressing portion 112 may be changed to correspond to the shape of the sealing area 12a.

[0083] Meanwhile, a pair of thickness adjustment stoppers 113 may be provided on both sides of the pressing portion 112 .

[0084] Specifically, the thickness adjustment stopper 113 is configured to adjust the thickness of the sealing area 12a pressurized by the press portion 112, and may be protruded from the main body portion 111 toward the battery case 12 on both sides of the press portion 112.

[0085] Here, the protruding height of the thickness adjustment stopper 113 protruding from the main body portion 111 can be set in various ways, but it is preferable that the protruding height of the thickness adjustment stopper 113 be set to be greater than the protruding height of the press portion 112. The protruding height of the thickness adjustment stopper 113 can be understood as the height from one surface of the main body portion 111 to one surface of the thickness adjustment stopper 113 that is located in the opposite direction from the main body portion 111 and contacts the battery case 12, and the protruding height of the press portion 112 can be understood as the height from one surface of the main body portion 111 to one surface of the press portion 112 that is located in the opposite direction from the main body portion 111 and contacts the battery case 12.

[0086] Meanwhile, the primary seal units 110 may be disposed above and below the battery case 12, as shown in Fig. 4. Here, the primary seal unit 110 disposed above the battery case 12 may further include an inclination adjustment unit 115 that adjusts the inclination of the main body part 111 and the press part 112 so that the thickness of the seal area 12a of the battery case 12 is uniform.

[0087] Specifically, the primary sealing unit 110 may further include a lifting section 114 that is connected to an external lifting device (not shown) and moves up and down, and an inclination adjustment section 115 that is provided between the lifting section 114 and the main body section 111 and adjusts the inclination of the main body section 111 and the press section 112.

[0088] More specifically, the tilt adjustment unit 115 may include a connecting unit 115a that connects the lifting / lowering unit 114 and the main body unit 111, and a pair of deformation units 115b whose ends are connected to the lifting / lowering unit 114 and the main body unit 111 and that undergo contraction and deformation.

[0089] That is, when one of the pair of deformation portions 115b contracts, the other is pulled, thereby adjusting the inclination of the main body portion 111 and the pressing portion 112. Here, the connecting portion 115a may be provided rotatably.

[0090] Meanwhile, the tilt adjustment unit 115 may further include a pair of tilt stoppers 115c for limiting the degree of tilt of the main body unit 111 and the press unit 112. Here, the tilt stoppers 115c may be provided spaced apart and protruded opposite to each other from the lifting / lowering unit 114 and the main body unit 111. Therefore, the tilt stoppers 115c can mechanically limit the tilt of the main body unit 111 and the press unit 112 when the main body unit 111 and the press unit 112 are tilted beyond a preset angle.

[0091] Battery case sealing method 5, the present invention provides a method for sealing a battery case 12, including a first heating step (S10) of heating a battery case 12 containing an electrode assembly 11, a first sealing step (S20) of pressurizing and sealing the battery case 12 after the first heating step (S10), and a second heating step (S30) of heating the battery case 12 after the first sealing step (S20). Here, each of the steps may be performed simultaneously with the transfer of the battery case 12.

[0092] Here, the first heating step (S10) is a step of heating the battery case 12 in which the electrode assembly 11 is housed, and can be performed in various ways.

[0093] Specifically, the first heating step (S10) can be performed by heating the battery case 12 using a primary heating unit 120 located in front of the primary sealing unit 110 before the first sealing step (S20). Therefore, the first heating step (S10) has the advantage of ensuring that the amount of heat required for sealing the battery case 12 is provided in advance before the sealing step is performed. Here, the details regarding the primary heating unit 120 are as described above.

[0094] In such a first heating step (S10), the battery case 12 can be heated along the transfer direction of the battery case 12. As a result, in the first heating step (S10), heat loss that may occur during transfer of the battery case 12 can be minimized.

[0095] In the first heating step (S10), the battery case 12 can be heated in a non-contact manner. Specifically, the first heating step (S10) can be performed by heating the battery case 12 in a non-contact manner using high frequency, infrared rays, ultraviolet rays, or the like.

[0096] Meanwhile, after the first heating step (S10), a first sealing step (S20) of sealing the battery case 12 can be performed.

[0097] Specifically, the first sealing step (S20) is a step of pressurizing and sealing the battery case 12 after the first heating step (S10), and can be performed in various ways. Here, the first sealing step (S20) can be performed by the above-mentioned primary sealing unit 110, and the above-mentioned content is incorporated by reference for specific details regarding the primary sealing unit 110.

[0098] Here, in the first sealing step (S20), at least one of the first sealing area 12aa, the second sealing area 12ab, and the third sealing area 12ac can be sealed by applying pressure.

[0099] Here, in the present invention, if a second sealing step (S40) described later is further provided, in the first sealing step (S20), sealing may be limited to the first sealing area 12aa located corresponding to the electrode lead 13.

[0100] That is, in the first sealing step (S20), sealing may be limited to the first sealing area 12aa, taking into consideration that if sealing is performed multiple times in the same sealing area 12a, a sealing step may occur, and that the electrode lead 13, which has a lower temperature rise rate than the battery case 12, will lose the heat required for sealing, resulting in a decrease in sealing quality at the position corresponding to the electrode lead 13.

[0101] Meanwhile, after the first sealing step (S20) is performed, a second heating step (S30) of heating the battery case 12 may be performed.

[0102] Specifically, the second heating step (S30) is a step of heating the battery case 12 after the first sealing step (S20), and can be performed in various ways.

[0103] Specifically, the second heating step (S30) can be performed by heating the battery case 12 using a primary heating unit 120 located behind the primary sealing unit 110 after the first sealing step (S20). Here, the details regarding the primary heating unit 120 are the same as those described above.

[0104] Therefore, in the second heating step (S30), after the sealing step is performed, the internal resin layer of the sealing region 12a can be sufficiently melted, and the generation of bubbles due to a sudden temperature change can be minimized.

[0105] Furthermore, in the present invention, when the second sealing step (S40) described later is further provided and sealing is performed multiple times, the second heating step (S30) ensures that the internal resin layer of the sealing area 12a is sufficiently melted before sealing by the second sealing step (S40), which of course helps to improve the sealing quality.

[0106] In the second heating step (S30), the battery case 12 can be heated along the transfer direction of the battery case 12. Thus, in the second heating step (S30), heat loss that may occur during transfer of the battery case 12 can be minimized.

[0107] In the second heating step (S30), the battery case 12 can be heated in a non-contact manner. Specifically, the second heating step (S30) can be performed by heating the battery case 12 in a non-contact manner using high frequency, infrared rays, ultraviolet rays, or the like.

[0108] Meanwhile, the method for sealing the battery case 12 according to the present invention may further include a second sealing step (S40) of sealing the battery case 12 after performing the first sealing step (S20) and the second heating step (S30).

[0109] Specifically, the second sealing step (S40) is a step of pressurizing and sealing the battery case 12 after the first sealing step (S20) and the second heating step (S30) are performed, and can be performed in various ways.

[0110] Here, in the second sealing step (S40), the aforementioned secondary sealing unit 140 may be used to pressurize and seal the area that was not pressurized in the first sealing step (S20), or may be used to additionally pressurize the area that was pressurized and sealed in the first sealing step (S20) to supplement the sealing of the battery case 12. Here, the same description as above applies to the secondary sealing unit 140.

[0111] Specifically, in the second sealing step (S40), at least one of the first sealing area 12aa, the second sealing area 12ab, and the third sealing area 12ac can be sealed.

[0112] Here, the pressing area for pressing the battery case 12 in the second sealing step (S40) may be larger than the pressing area for pressing the battery case 12 in the first sealing step (S20).

[0113] Specifically, the area sealed in the second sealing step (S40) may be larger than the area sealed in the first sealing step (S20), taking into consideration that the area not sealed in the first sealing step (S20) must be sealed to form a sealed structure for the battery case 12, and that even an area sealed in the first sealing step (S20) may be further sealed to supplement the sealing quality.

[0114] For example, if only the first sealing area 12aa is sealed in the first sealing step (S20), the second sealing step (S40) may seal at least one of the second sealing area 12ab and the third sealing area 12ac together with the first sealing area 12aa. That is, if only the first sealing area 12aa is sealed in the first sealing step (S20), the second sealing step (S40) may seal the first sealing area 12aa and the second sealing area 12ab.

[0115] Meanwhile, the method for sealing a battery case according to the present invention may further include a post-heating step (S50) of heating the battery case 12 after performing the second sealing step (S40).

[0116] Specifically, the post-heating step (S50) is a step of heating the battery case 12 after the second sealing step (S40) is performed, and can be performed in various ways.

[0117] Specifically, the post-heating step (S50) can be performed by heating the battery case 12 using a secondary heating unit 150 located behind the secondary sealing unit 140 after the second sealing step (S40). Therefore, in the post-heating step (S50), the internal resin layer of the sealing region 12a can be sufficiently melted, and the generation of bubbles due to a sudden temperature change can be minimized. Here, the details regarding the secondary heating unit 150 are as described above.

[0118] In such a post-heating step (S50), the battery case 12 can be heated along the transfer direction of the battery case 12. Thus, in the post-heating step (S50), heat loss that may occur during transfer of the battery case 12 can be minimized.

[0119] In the post-heating step (S50), the battery case 12 can be heated in a non-contact manner. Specifically, the post-heating step (S50) can be performed by heating the battery case 12 in a non-contact manner using high frequency, infrared rays, ultraviolet rays, or the like.

[0120] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and various implementations within the technical spirit of the present invention and the scope of equivalents of the appended claims can be made by a person having ordinary skill in the art to which the present invention pertains. [Explanation of symbols]

[0121] 10 Secondary battery 11 Electrode assembly 12 Battery case 12' storage area 12a Seal area 12aa First seal area 12ab Second seal area 12ac 3rd seal area 13 Electrode Lead 100 Battery case sealing device 110 Primary seal unit 111 Main body 112 Press Department 113 Thickness adjustment stopper 114 Lifting section 115 Tilt adjustment unit 115a Connection part 115b Deformed part 115c Tilt stopper 120 Primary heating unit 130 Transfer section 140 Secondary seal unit 150 Secondary heating unit S10 First heating step S20 1st seal step S30 Second heating step S40 2nd seal step S50 Post-heating step

Claims

1. a primary seal unit that applies pressure to seal a battery case in which the electrode assembly is housed; a pair of primary heating units positioned in front of and behind the primary sealing unit, respectively, to heat the battery case; a transfer unit that transfers the battery case along a transfer line; a secondary sealing unit located behind the primary sealing unit and the primary heating unit, which pressurizes and seals the battery case; a secondary heating unit located behind the secondary sealing unit and configured to heat the battery case; A battery case sealing device comprising:

2. the primary heating unit is formed on the transfer line along a transfer direction of the battery case, 2. The battery case sealing device according to claim 1, wherein, based on the transport direction of the battery case, one of the pair of primary heating units is located in front of the primary sealing unit and the other of the pair of primary heating units is located behind the primary sealing unit.

3. The battery case sealing device according to claim 1 , wherein the primary heating unit heats the battery case in a non-contact manner.

4. The battery case has an electrode lead protruding from at least one end thereof and electrically connected to the electrode assembly, The battery case sealing device according to claim 1 , wherein the primary seal unit applies pressure to an area of ​​the battery case corresponding to the electrode lead to seal the area.

5. The battery case further includes a transfer unit that transfers the battery case. The battery case sealing device according to claim 1 , wherein the secondary heating unit extends along a direction in which the battery case is transferred.

6. The battery case sealing device according to claim 1 , wherein the secondary heating unit heats the battery case in a non-contact manner.

7. The battery case sealing device according to claim 1 , wherein a pressure area over which the secondary seal unit presses the battery case is larger than a pressure area over which the primary seal unit presses the battery case.

8. a first heating step of heating a battery case in which the electrode assembly is housed; a first sealing step of pressurizing and sealing the battery case after the first heating step; a second heating step of heating the battery case after the first sealing step; a second sealing step of pressurizing and sealing the battery case after the first sealing step and the second heating step are performed; a post-heating step of heating the battery case after the second sealing step; A method for sealing a battery case, comprising:

9. In at least one of the first heating step and the second heating step, The battery case sealing method according to claim 8 , wherein the battery case is heated along a direction in which the battery case is transferred.

10. In at least one of the first heating step and the second heating step, The method for sealing a battery case according to claim 8 , wherein the battery case is heated in a non-contact manner.

11. In the first sealing step, The method for sealing a battery case according to claim 8 , wherein the sealing is performed at a position corresponding to an electrode lead protruding from at least one end of the electrode assembly.

12. folding the battery case housing the electrode assembly; and sealing a portion of the outer periphery of the battery case, A method for producing a pouch-type secondary battery, wherein the sealing step is performed by the method for sealing a battery case according to any one of claims 8 to 11.

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