rechargeable battery sealing device

Abstract

The present invention relates to a sealing device for a secondary battery, and more particularly to a sealing device for a secondary battery that seals a secondary battery including a pouch-type battery case. The present invention provides a sealing device for a secondary battery, comprising a pair of sealing portions arranged facing each other with a battery case having an electrode assembly built therein therebetween, the distance between which is adjustable, and at least one detection portion provided between the pair of sealing portions for detecting a change in pressure due to a change in the gap between the pair of sealing portions.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0015838, filed on February 7, 2022, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a sealing device for a secondary battery, and more particularly, to a sealing device for a secondary battery that seals a secondary battery including a pouch-type battery case.

Background Art

[0003] As technology development and demand related to mobile devices increase, the demand for secondary batteries as an energy source has been rapidly increasing. Among such secondary batteries, many studies have been conducted on lithium secondary batteries having high energy density and discharge voltage, and they have also been commercialized and widely used.

[0004] Generally, a lithium secondary battery is configured by stacking or winding an electrode assembly composed of a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and then incorporating it into a battery case made of a metal can or a laminate sheet, and then injecting or impregnating an electrolyte.

[0005] In recent years, due to the high capacity of secondary batteries, there has been a lot of interest in increasing the area of the case and processing it into a thin material. As a result, the usage amount of pouch-type secondary batteries having a structure in which a stack-type or stack / folding-type electrode assembly is incorporated into a laminate sheet pouch-type battery case has been gradually increasing due to low manufacturing costs, small weight, and easy form deformation.

[0006] On the other hand, the battery case (S) of such a pouch-type secondary battery has a sealed structure by being sealed by a sealing device in order to prevent the external outflow and damage of the electrode assembly and the electrolyte inside the battery case (S).

[0007] Figures 1a and 1b show how a conventional sealing device 1 seals a battery case (S). As shown in Figures 1a and 1b, a conventional sealing device 1 is generally provided in pairs and positioned above and below the secondary battery (S), respectively, and then seals the battery case (S) by applying a certain temperature and pressure.

[0008] Specifically, the conventional sealing device 1 may have a structure that includes a sealing block 2 that is provided to move up and down toward the secondary battery (S) and pressurizes the secondary battery (S), and a protruding portion 3 that is formed to protrude from one surface of the sealing block 2 at a predetermined height.

[0009] In particular, by arranging the protrusions 3 of the pair of sealing devices 1 to face each other, as shown in Figure 1a, when the sealing device 1 moves a certain distance or more toward the battery case (S), the protrusions 3 of the pair of sealing devices 1 come into contact with each other, thereby restricting the movement of the sealing device 1 and preventing the battery case from being excessively pressed.

[0010] However, as shown in Figure 1b, if the initial thickness of the sealing portion of the battery case (S) is set to a certain level or higher due to tolerances of the sealing material, the protrusions 3 of the pair of sealing devices 1 cannot come into contact with each other and are separated by a predetermined distance (G). Conventionally, the user would visually check the distance (G) between the protrusions 3 and adjust the distance between the sealing devices 1. However, if it is difficult to visually check the distance (G) between the protrusions 3, there is a problem in that the user may not notice the abnormal condition.

[0011] As a result, the sealing portion of the battery case (S) could not be sufficiently compressed, leading to a problem where it was formed with a thickness exceeding the predetermined thickness. Consequently, the thickness of the sealing portion of multiple battery cases (S) became uneven, and the process conditions during the initial equipment setup differed from those after mass production, hindering process stability. Therefore, technology is needed to solve the above problem. [Overview of the project] [Problems that the invention aims to solve]

[0012] The present invention was made to solve the above-mentioned problems, and the object of the present invention is to provide a secondary battery sealing device that can maintain a uniform thickness of the sealing portion of the battery case when sealing the battery case of a secondary battery. [Means for solving the problem]

[0013] The present invention provides a sealing device for a secondary battery, comprising: a pair of sealing parts arranged to face each other with a battery case containing an electrode assembly in between, and provided so as to be able to adjust the distance between them; and at least one detection unit provided between the pair of sealing parts for detecting pressure changes due to changes in the distance between the pair of sealing parts.

[0014] The sealing portion may include a sealing block that pressurizes and seals the sealing portion of the battery case, and a pair of protrusions formed protruding from one surface of the sealing block facing the battery case.

[0015] The pair of protrusions of the sealing portion can be arranged to face each other. The pair of protrusions can be formed protruding from both ends of the seal block.

[0016] The detection unit can be fixedly mounted on the protruding portion. The detection unit can be pressed between the protruding portions of the pair of sealing portions.

[0017] The detection unit can be fixedly supported by at least one of the pair of sealing units. The detection unit may include at least one pressure sensor.

[0018] On the other hand, the sealing device for a secondary battery according to the present invention can further include an output interface that outputs an alarm according to the pressure value detected by the detection unit.

[0019] In addition, the sealing device for a secondary battery according to the present invention can further include a control unit that compares the pressure value acquired by the detection unit with a preset pressure value and controls the moving distance of the sealing part.

Effect of the Invention

[0020] The present invention includes at least one detection unit that detects a pressure change due to a change in the interval between the pair of sealing parts, and controls the mutual interval of the pair of sealing parts based on the pressure value detected by the detection unit, thereby ensuring a uniform thickness of the sealing site.

Brief Description of the Drawings

[0021] [Figure 1a] It is a conceptual diagram showing how a conventional sealing device for a pair of secondary batteries seals a battery case. [Figure 1b] It is a conceptual diagram showing how the sealing device for the secondary battery in Fig. 1a seals the battery case in a state where they are not in contact with each other. [Figure 2a] It is a conceptual diagram showing a state where the pair of sealing devices for secondary batteries according to the first embodiment of the present invention are separated from each other. [Figure 2b] It is a conceptual diagram showing how the pair of sealing devices for secondary batteries in Fig. 2a contact each other and seal the battery case. [Figure 3a] It is a conceptual diagram showing a state where the pair of sealing devices for secondary batteries according to the second embodiment of the present invention are separated from each other. [Figure 3b] It is a conceptual diagram showing how the pair of sealing devices for secondary batteries in Fig. 3a contact each other and seal the battery case. [Figure 4] It is a schematic diagram showing the state of the sealing device for a secondary battery according to the third embodiment of the present invention.

Modes for Carrying Out the Invention

[0022] Hereinafter, with reference to the accompanying drawings, the preferred embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement it. However, the present invention may be realized in various different forms and is not limited or restricted by the following embodiments.

[0023] To clearly explain the present invention, detailed descriptions of parts not related to the explanation or related known technologies that may unnecessarily obscure the gist of the present invention are omitted. In this specification, when attaching reference signs to the components of each drawing, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0024] Also, the terms and words used in this specification and the claims should not be construed by being limited to their ordinary or dictionary meanings. The inventors should interpret them according to the principle that they can appropriately define the concepts of the terms in order to explain their invention in the best way, and should interpret them in meanings and concepts consistent with the technical idea of the present invention.

[0025] The present invention provides a sealing device 10 for a secondary battery, which includes a pair of sealing parts 100 arranged to face each other with a battery case (S) having a built-in electrode assembly (not shown) interposed therebetween and provided such that the mutual distance can be adjusted, and at least one detection part 200 provided between the pair of sealing parts 100 and detecting a pressure change due to a change in the interval between the pair of sealing parts 100.

[0026] Specifically, the sealing part 100 is configured to be arranged to face each other with a battery case (S) having a built-in electrode assembly interposed therebetween and provided such that the mutual distance can be adjusted, and various configurations are possible.

[0027] Here, the electrode assembly may have a configuration in which positive and negative electrodes and separators are arranged alternately. More specifically, the electrode assembly may have a structure in which a positive electrode current collector / positive electrode active material layer / separator / negative electrode active material layer / negative electrode current collector is stacked in that order, with the positive electrode active material layer on one side of the separator facing the negative electrode active material layer on the other side. Such an electrode assembly can be built into a battery case (S).

[0028] The battery case (S) can have a sealed structure by being sealed by a secondary battery sealing device 10 to prevent the internal electrode assembly and electrolyte from leaking out and to prevent the electrode assembly and electrolyte from being damaged by exposure to external air and moisture.

[0029] For example, the sealing portion 100 may include a sealing block 110 that pressurizes and seals the sealing portion of the battery case (S), and a pair of protrusions 120 formed protruding from one surface of the sealing block 110 facing the battery case (S).

[0030] Here, the seal block 110 is configured to pressurize and seal the sealing portion of the battery case (S), and various configurations are possible. In this case, the sealing portion is the portion of the battery case (S) that is sealed, and may include at least one edge of the outer periphery of the battery case (S). For example, the sealing portion can be formed along the circumferential direction of the battery case (S).

[0031] Specifically, the seal block 110 can pressurize and seal the sealing portion of the battery case (S) by moving in accordance with the sealing portion of the battery case (S). In this case, the sealing portion 100 further includes a connecting portion 130, one end of which is connected to the seal block 110 and the other end of which is connected to a moving means (not shown), thereby allowing the seal block 110 to be moved. Here, the moving means may include a drive device such as an actuator.

[0032] The seal block 110 may further include a heating section (not shown) to allow the sealing portion to be heat-fused by heating it simultaneously with pressurizing it. The heating section can heat the sealing portion to a temperature above room temperature.

[0033] Here, "room temperature" refers to the temperature range commonly known in this industry as "room temperature" or ambient temperature. That is, it refers to the temperature of a laboratory or research room, and is used to describe temperature conditions when experiments are conducted without specifying or adjusting the temperature, or when samples and substances are left in the room. It refers to the ambient temperature of the room. Generally, it is a temperature at which humans can comfortably live, typically around 15°C to 20°C.

[0034] As a result, the temperature exceeding room temperature may be 20°C or higher, and more specifically, if the sealing layer heat-fused at the sealing portion is made of polypropylene resin, it can be set to 160°C to 190°C.

[0035] On the other hand, the seal block 110 can have various shapes, such as a bar shape. In this case, a pair of protrusions 120 can be formed on one surface of the seal block 110, projecting in one direction, as shown in Figures 2a to 3b.

[0036] Specifically, the protrusion 120 is formed to protrude from one surface of the seal block 110 facing the battery case (S), and various configurations are possible. More specifically, the pair of protrusions 120 can be formed to protrude from both ends of the seal block 110. In this case, the pair of protrusions 120 of the seal portion 100 can be arranged to face each other.

[0037] In other words, when a pair of sealing portions 100 move a certain distance or more toward the battery case (S), at least one of the protruding portions 120, which are arranged to face each other, comes into contact with the detection unit 200, which will be described later, thereby restricting the movement of the sealing portions 100.

[0038] For example, as shown in Figures 2a to 3b, if a detection unit 200, described later, is fixedly attached to one of the protruding portions 120 that are arranged facing each other, the movement of the sealing portion 100 can be restricted by the protruding portion 120 that does not have the detection unit 200 coming into contact with the detection unit 200.

[0039] As a result, the protrusion 120 prevents the sealing portion of the battery case (S) from being excessively compressed, and prevents the thickness of the sealing portion from becoming thinner than a preset thickness. Here, the thickness can be understood as the height in the Z direction based on Figures 2a to 3b, and the same can be understood below.

[0040] On the other hand, the secondary battery sealing device 10 according to the present invention may include a detection unit 200 to prevent the thickness of the sealing portion of the battery case (S) from exceeding a preset thickness due to insufficient pressure being applied to the sealing portion.

[0041] Such a detection unit 200 is provided between the pair of sealing parts 100 and includes at least one detection unit 200 that detects pressure changes due to changes in the distance between the pair of sealing parts 100, and a variety of configurations are possible.

[0042] For example, the detection unit 200 may include at least one pressure sensor. Here, various pressure sensors such as resonant pressure sensors, piezoelectric pressure sensors, strain gauge pressure sensors, and capacitive pressure sensors can be used as the pressure sensor.

[0043] Specifically, the detection unit 200 is provided between a pair of sealing portions 100 and can detect the pressure value that changes simultaneously when the pair of sealing portions 100 come into contact with each other. In this case, the change in pressure value detected by the detection unit 200 may indicate that the sealing portion of the battery case (S) is being compressed.

[0044] On the other hand, if the pair of sealing portions 100 move less than a certain distance and cannot sufficiently pressurize the detection unit 200 or make contact with the detection unit 200, the pressure value detected by the detection unit 200 may be less than a preset pressure value. Here, the preset pressure value can be understood as the pressure value detected by the detection unit 200 corresponding to the point in time when the thickness of the sealing portion of the battery case (S) has a preset thickness.

[0045] For example, if the detection unit 200 cannot make contact with the pair of sealing parts 100, the pressure value of the detection unit 200 will not change from the initial setting value. Here, if the initial setting value is "0", the pressure value of the detection unit 200 may also be "0".

[0046] In other words, the user can recognize that if the pressure value of the detection unit 200 is less than a preset pressure value, the sealing portion of the battery case (S) will not be sufficiently compressed. Therefore, the user can sufficiently pressurize the sealing portion by controlling the distance between the pair of sealing portions 100 to be closer together. This allows the thickness of the sealing portion of the battery case (S) to be uniformly adjusted.

[0047] Such a detection unit 200 can be provided between the pair of sealing parts 100, and in this case, it may be fixed to the pair of sealing parts 100, or it may be fixed by another device provided between the pair of sealing parts 100.

[0048] However, in order to reduce manufacturing costs and simplify the structure, it is preferable that the detection unit 200 be fixedly attached to a pair of sealing parts 100. In this case, the detection unit 200 can be fixedly supported to at least one of the pair of sealing parts 100.

[0049] As an example, the detection unit 200 may be fixedly attached to the seal portion 100 located on the lower side of the battery case (S), one of a pair of seal portions 100, as shown in Figures 2a to 2b. As another example, the detection unit 200 may be fixedly attached to the seal portion 100 located on the upper side of the battery case (S), one of a pair of seal portions 100, as shown in Figures 3a to 3b.

[0050] In this case, it is preferable that the detection unit 200 is fixedly provided on the protruding portion 120. That is, the detection unit 200 can be pressed between the protruding portions 120 of the pair of sealing portions 100, as shown in Figures 2b and 3b.

[0051] On the other hand, the secondary battery sealing device according to the present invention may further include an output interface 300 that outputs an alarm in accordance with the pressure value detected by the detection unit 200, as shown in Figure 4.

[0052] Specifically, the output interface 300 is configured to output an alarm in accordance with the pressure value detected by the detection unit 200, and various configurations are possible.

[0053] For example, the output interface 300 can receive the pressure value detected by the detection unit 200 using a short-range wired communication method such as CAN (Controller Area Network), serial communication, or Ethernet (registered trademark), or a wireless communication method such as Bluetooth (registered trademark), infrared data association, ZigBee (registered trademark), or Wi-Fi (registered trademark), and output it as an image and / or sound.

[0054] Such an output interface 300 may include a display module that outputs an alarm corresponding to the pressure value as an image, and / or a speaker module that outputs the alarm corresponding to the pressure value as a sound.

[0055] On the other hand, the secondary battery sealing device according to the present invention may further include a control unit 400 that controls the movement distance of the sealing unit 100 by comparing the pressure value acquired by the detection unit 200 with a preset pressure value.

[0056] Specifically, the control unit 400 controls the movement distance of the seal unit 100 by comparing the pressure value acquired by the detection unit 200 with a preset pressure value, and various configurations are possible.

[0057] For example, if the pressure value detected by the detection unit 200 is smaller than a preset pressure value, the control unit 400 can control the distance the pair of seals 100 move so that they move closer to each other.

[0058] Furthermore, it goes without saying that the control unit 400 can control the movement distance of the pair of seal portions 100 so that they move closer to each other if the pressure value detected by the detection unit 200 is greater than a preset pressure value.

[0059] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and can be implemented in various ways by persons with ordinary skill in the art to which the present invention pertains, within a scope equivalent to the technical concept of the present invention and the claims described below. [Explanation of Symbols]

[0060] 10: Sealing device for secondary batteries 100: Seal part 110: Seal Block 120:Protrusion 130: Connection part 200: Detection unit 300: Output Interface 400: Control Unit

Claims

1. A battery case containing an electrode assembly is placed between them, with a pair of sealing parts positioned facing each other and with an adjustable distance between them, A detection unit is provided between the pair of sealing portions and detects pressure changes due to changes in the distance between the pair of sealing portions, Includes, The aforementioned sealing portion is A sealing block that pressurizes and seals the sealing portion of the battery case, A sealing device for a secondary battery, comprising a pair of protrusions formed protruding from one surface of the sealing block facing the battery case.

2. The sealing device for a secondary battery according to claim 1, wherein the pair of protrusions of the sealing portions are arranged to face each other.

3. The sealing device for a secondary battery according to claim 1, wherein the pair of protrusions are formed protruding from both ends of the seal block.

4. The detection unit is fixedly provided on the protruding portion, as described in claim 1, for the sealing device of a secondary battery.

5. The sealing device for a secondary battery according to claim 1, wherein the detection unit is pressed between the protruding portions of the pair of sealing portions.

6. The sealing device for a secondary battery according to claim 1, wherein the detection unit is fixedly supported by at least one of the pair of sealing units.

7. The sealing device for a secondary battery according to claim 1, wherein the detection unit includes at least one pressure sensor.

8. The secondary battery sealing device according to claim 1, further comprising an output interface that outputs an alarm in accordance with the pressure value detected by the detection unit.

9. A secondary battery sealing device according to any one of claims 1 to 8, further comprising a control unit that controls the movement distance of the sealing unit by comparing the pressure value acquired by the detection unit with a preset pressure value.

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