Battery cell and method for manufacturing same

Abstract

A battery cell according to an embodiment of the present invention may comprise: an inner cell in which an electrode assembly is accommodated in a pouch-type exterior material; a case which accommodates the inner cell and has higher rigidity than the exterior material; an end cover which covers the end of the case and has an insulating material; and a pad which is in close contact between the inner surface of the case and the outer surface of the inner cell and is elastically deformed.

Description

Battery cell and method for manufacturing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2024-0097194, filed July 23, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a battery cell including an electrode assembly and a pouch-shaped outer packaging material and a method for manufacturing the same.

[0005] Secondary batteries that can be recharged and discharged are suitable for use as built-in battery cells because replacement of the battery cells is unnecessary. As the stability of secondary batteries is rapidly improving and their capacity is increasing, they are being applied to various devices.

[0006] For example, secondary batteries are not only widely used as energy sources for multifunctional small products such as wireless mobile devices or wearable devices worn on the body, but are also used as energy sources or energy storage systems (ESS) for electric vehicles and hybrid electric vehicles, which are presented as alternatives to existing gasoline and diesel vehicles that cause air pollution.

[0007] In particular, to utilize secondary batteries as a large-capacity, high-output energy source, battery modules comprising multiple battery cells or battery packs comprising multiple battery modules are being used. As secondary batteries are increasingly used as large-capacity, high-output energy sources, ensuring their safety is becoming a significant concern.

[0008] Meanwhile, battery cells can be categorized into prismatic, pouch, and cylindrical types based on their shape. Among these, pouch-type cells offer the advantages of being relatively lightweight, offering high energy density, and allowing for a variety of designs. However, their thinness and lightness make them vulnerable to external impacts, increasing the risk of fire. Conversely, prismatic cells, while relatively heavy, offer the advantages of being resistant to external impacts and efficient at dissipating heat.

[0009] Since each type of battery cell has its own advantages and disadvantages, it would be desirable to diversify the production line.

[0010] The problem to be solved by the present invention is to provide a battery cell that can be manufactured using a pouch-type battery cell and has improved safety, and a method for manufacturing the same.

[0011] A battery cell according to an embodiment of the present invention may include an inner cell in which an electrode assembly is accommodated in a pouch-shaped outer material; a case that accommodates the inner cell and has higher rigidity than the outer material; an end cover that covers an end of the case and has an insulating material; and a pad that is in close contact with and elastically deforms between the inner surface of the case and the outer surface of the inner cell.

[0012] The electrode leads of the inner cell may extend toward the end of the case and protrude outward from the end cover.

[0013] The above pad can be attached to the outer surface of the inner cell.

[0014] The above pads may be provided in pairs arranged on both sides in the thickness direction of the inner cell.

[0015] A groove through which the electrode lead of the inner cell passes may be formed in the end cover.

[0016] The end cover may include a first end cover covering a portion of an end of the case; and a second end cover covering another portion of an end of the case and in contact with the first end cover. The electrode lead of the inner cell may protrude outside the case through a space between the first end cover and the second end cover.

[0017] At least one of the first end cover or the second end cover may have a groove formed through which the electrode lead passes.

[0018] In the above case, a single inner cell can be accommodated.

[0019] The case may include a base portion located on one side of the inner cell in the thickness direction; a pair of side portions facing each other in the width direction of the inner cell and connected to the base portion; and a cover portion facing the base portion with the inner cell interposed therebetween and connecting the pair of side portions.

[0020] A method for manufacturing a battery cell according to an embodiment of the present invention may include the steps of: preparing an inner cell in which an electrode assembly is accommodated in a pouch-shaped outer material; attaching a pad having an elastically deformable material to an outer surface of the inner cell; and accommodating the inner cell with the pad attached in a case assembly. The case assembly may include a case that accommodates the inner cell, has higher rigidity than the outer material, and is separable into a case body and a case cover; and an end cover that covers an end of the case and has an insulating material.

[0021] The step of accommodating the inner cell in the case assembly may include the steps of assembling a first end cover to the case body; accommodating the inner cell in the case body, wherein the electrode lead of the inner cell protrudes outwardly from the first end cover; assembling a second end cover to the first end cover and / or the case body, wherein the electrode lead protrudes outwardly through a gap between the first end cover and the second end cover; and coupling the case cover to the case body.

[0022] According to a preferred embodiment of the present invention, the safety of the battery cell can be increased and the risk of fire can be reduced by a case having high rigidity and a pad capable of shock absorption.

[0023] Additionally, assembly of the battery cell can be facilitated by end covers that insulate the electrode leads.

[0024] In addition, since it includes an inner cell, which is a pouch-type battery cell, it has the advantage of being able to use the existing pouch-type battery cell production line as is.

[0025] In addition, the configurations according to preferred embodiments of the present invention may include effects that can be easily predicted by those skilled in the art.

[0026] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0027] Figure 1 is a perspective view of a pouch-type battery cell.

[0028] Figure 2 is a perspective view of a battery cell according to one embodiment of the present invention.

[0029] Figure 3 is an exploded perspective view of the battery cell illustrated in Figure 2.

[0030] Figure 4 is a drawing showing a state in which the pad illustrated in Figure 3 is separated from the inner cell.

[0031] Figure 5 is a flowchart of a battery cell manufacturing method according to another embodiment of the present invention.

[0032] Figure 6 is a specific flowchart of step S30 illustrated in Figure 5.

[0033] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0034] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0035] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0036] In the drawing, each component of a secondary battery according to one embodiment of the present invention is schematically illustrated, and the size of the component or the thickness of the line may be expressed somewhat exaggerated for the convenience of understanding.

[0037] Figure 1 is a perspective view of a pouch-type battery cell.

[0038] A pouch-type battery cell (100) may include an electrode assembly (110), a pouch-type outer material (120), and an electrode lead (130).

[0039] The electrode assembly (110) may be formed by alternately interposing a positive electrode and a negative electrode with a separator therebetween. That is, the electrode assembly (110) may include a positive electrode, a negative electrode, and a separator interposed therebetween to mutually insulate the positive electrode and the negative electrode. The electrode assembly (110) may be of a stack type, a jelly roll type, a stack and folding type, etc., but is not limited thereto.

[0040] The electrode assembly (110) may include an electrode tab connected to an electrode lead (130). The electrode tab may be formed by cutting the non-conductive portions of the positive and negative electrodes, or by connecting a separate conductive member to the non-conductive portion.

[0041] The electrode lead (130) can be connected to the electrode assembly (110), more specifically, to the electrode tab. The electrode lead (130) can protrude to the outside of the pouch-shaped outer material (120). A pair of electrode leads (130) can be provided that are electrically connected to the positive and negative electrodes. For example, as illustrated in FIG. 1, a pair of electrode leads (130) can protrude to both sides with respect to the electric length direction of the pouch-shaped battery cell (100). However, the present invention is not limited thereto, and it is of course possible for a pair of electrode leads (130) to protrude in the same direction while being parallel to each other.

[0042] The pouch-shaped outer shell (120) can accommodate the electrode assembly (110). The pouch-shaped outer shell (120) can be manufactured by forming a laminate sheet, and the laminate sheet can include a first resin layer (e.g., polypropylene) positioned at the outermost side on one side, a second resin layer (e.g., polyethylene terephthalate) positioned at the outermost side on the other side, and a metal layer (e.g., aluminum) positioned between the first resin layer and the second resin layer.

[0043] Due to the configuration of the pouch-shaped outer shell (120), the pouch-shaped battery cell (100) is relatively light and has a high energy density, but has the disadvantages of being vulnerable to external impact and having a high risk of fire. The present invention provides a battery cell (10) that can overcome these disadvantages, and will be described in detail below.

[0044] FIG. 2 is a perspective view of a battery cell according to one embodiment of the present invention, FIG. 3 is an exploded perspective view of the battery cell illustrated in FIG. 2, and FIG. 4 is a drawing illustrating a state in which the pad illustrated in FIG. 3 is separated from the inner cell.

[0045] A battery cell (10) according to one embodiment of the present invention may include an inner cell (100), a case (200), an end cover (300), and a pad (400).

[0046] The inner cell (100) can accommodate an electrode assembly (110) in a pouch-shaped outer material (120). That is, the inner cell (100) can be a pouch-shaped battery cell (100) described above, and the description thereof is cited.

[0047] The case (200) accommodates the inner cell (100) and may have higher rigidity than the inner cell (100). Preferably, a single inner cell (100) may be accommodated in the case (200). Accordingly, the battery cell (10) may replace a conventional pouch-type battery cell. However, if necessary, a plurality of inner cells (100) may also be accommodated.

[0048] For example, the case (200) may be made of a metal material. That is, the case (200) may be manufactured by processing and fastening a metal plate. The thickness of the metal plate forming the case (200) may be thicker than the thickness of the laminate sheet forming the pouch-shaped outer material (120) of the inner cell (100).

[0049] Since the case (200) has relatively high rigidity, it can protect the inner cell (100) from external impact. In addition, in the event of a fire or other incident due to abnormal operation of the inner cell (100), it can delay or prevent the spread of flames and gases.

[0050] Additionally, the case (200) may be surface-treated with a metal (e.g., aluminum) that has corrosion resistance against electrolyte.

[0051] The case (200) may have a shape corresponding to the inner cell (100). More specifically, the case (200) may have a predetermined thickness parallel to the thickness direction of the inner cell (100) (the direction parallel to the Z-axis of FIG. 3), a predetermined width parallel to the width direction of the inner cell (100) (the direction parallel to the X-axis of FIG. 3), and a predetermined length parallel to the length direction of the inner cell (100) (the direction parallel to the Y-axis of FIG. 3). The thickness dimension, width dimension, and length dimension of the case (200) may increase in that order.

[0052] The case (200) may have a shape that surrounds the inner cell (100). An opening may be formed at both ends of the case (200) to be covered by an end cover (300) to be described later.

[0053] In more detail, the case (200) may include a base portion (210), a pair of side portions (220), and a cover portion (230).

[0054] The base portion (210) can be located on one side of the inner cell (100) in the thickness direction (in the direction parallel to the Z-axis of FIG. 3).

[0055] A pair of side portions (220) can be connected to the base portion (210) while facing each other in the width direction of the inner cell (100) (the direction parallel to the X-axis in FIG. 3).

[0056] The cover part (230) faces the base part (210) with the inner cell (100) in between, and can connect a pair of side parts (220).

[0057] The base portion (210) and the cover portion (230) may be plate-shaped facing the inner cell (100) in the thickness direction. The side portion (220) may be plate-shaped facing the inner cell (100) in the width direction. Based on the directions shown in FIGS. 2 and 3, the base portion (210) may define the bottom surface of the case (200), the side portion (220) may define the side surface of the case (200), and the cover portion (230) may define the top surface of the case (200).

[0058] The base portion (210), a pair of side portions (220), and the cover portion (230) may be formed as separate components, but are not limited thereto, and at least some of them may be formed as a single, integrally connected configuration.

[0059] The case (200) may be configured to be separable from the case body (201) and the case cover (202). That is, the case body (201) and the case cover (202) may be separably fastened to each other. The case body (201) may include a base portion (210), a pair of side portions (220), and a portion of the cover portion (230), and the case cover (202) may include another portion from the base portion (210), a pair of side portions (220), and the cover portion (230).

[0060] For example, as illustrated in FIG. 3, the case body (201) may include a base portion (210) and a pair of side portions (220), and the case cover (202) may include a cover portion (230).

[0061] In this way, the case body (201) and the case cover (202) are detachably fastened to each other, thereby facilitating the insertion of the inner cell (100) into the case (200), and facilitating the assembly of the end cover (300) described later.

[0062] Meanwhile, the end cover (300) can cover an end of the case (200). More specifically, an opening can be formed at the longitudinal end of the case (200), and the end cover (300) can cover the opening.

[0063] A pair of end covers (300) may be provided to cover both ends of the case (200). Each end cover (300) may have an insulating material. For example, the end cover (300) may include a polymer resin material such as polypropylene. Accordingly, the end cover (300) may insulate the electrode lead (130) of the inner cell (100) from the case (200).

[0064] In more detail, each end cover (300) may include a first end cover (310) that covers a portion of an end of the case (200) and a second end cover (320) that covers another portion of the end of the case (200). The first end cover (310) and the second end cover (320) may be in contact with each other. The first end cover (310) and the second end cover (320) may be arranged along the thickness direction of the inner cell (100). The first end cover (310) and the second end cover (320) may be formed to be long in the width direction of the inner cell (100).

[0065] That is, the first end cover (310) and the second end cover (320) can together cover the opening formed at the end of the case (200).

[0066] The electrode lead (130) of the inner cell (100) can protrude to the outside of the case (200) through the space between the first end cover (310) and the second end cover (320). Therefore, the electrode lead (130) can be connected to an external load located outside the case (200). In addition, the assembly of the inner cell (100) and the end cover (300) can be facilitated.

[0067] A groove (310a) (320a) through which the electrode lead (120) of the inner cell (100) passes may be formed in the end cover (300). More specifically, a groove (310a) (320a) through which the electrode lead (130) passes may be formed in at least one of the first end cover (310) and the second end cover (320). For example, a first groove (310a) may be formed in the first end cover (310), and a second groove (320a) may be formed in the second end cover (320). The first groove (310a) and the second groove (320a) may face each other and form a hole through which the electrode lead (130) passes together. However, the present invention is not limited thereto, and it is also possible to form only one of the first groove (310a) and the second groove (320a).

[0068] Meanwhile, the pad (400) is in close contact between the inner surface of the case (200) and the outer surface of the inner cell (100) and can be elastically deformed. The pad (400) may be a foam pad made of a material capable of elastic deformation, such as polyurethane.

[0069] In more detail, when the inner cell (100) swells, the pad (400) can be compressed between the inner surface of the case (200) and the outer surface of the inner cell (100). Therefore, the pad (400) can suppress swelling of the inner cell (100). In addition, the pad (400) can protect the inner cell (100) from external impact.

[0070] The size of the pad (400) may be the same as or similar to the size of the electrode assembly (110) of the inner cell (100). The pad (400) may be attached to the outer surface of the inner cell (100), more specifically, to the outer surface of the outer material (120). That is, an adhesive layer may be provided between the pad (400) and the outer material (120).

[0071] A pair of pads (400) may be provided on both sides of the inner cell (100) in the thickness direction. In more detail, pads (400) may be attached to both sides of the inner cell (100).

[0072] By the configuration of the battery cell (10) described above, the battery cell (10) can ensure safety against external impact and has the advantage of reducing the risk of fire.

[0073] FIG. 5 is a flowchart of a battery cell manufacturing method according to another embodiment of the present invention, and FIG. 6 is a specific flowchart of step S30 illustrated in FIG. 5.

[0074] Hereinafter, the manufacturing method of the battery cell (100) described above will be described as another embodiment of the present invention.

[0075] A battery cell manufacturing method (hereinafter, “manufacturing method”) according to another embodiment of the present invention may include a step (S10) of preparing an inner cell (100) in which an electrode assembly (110) is accommodated in a pouch-shaped outer material (120), a step (S20) of attaching a pad (400) having an elastically deformable material to an outer surface of the inner cell (100), and a step (S30) of accommodating the inner cell (100) to which the pad (400) is attached in a case assembly. The case assembly may include a case (200) and an end cover (300). That is, the case (200) and the end cover (300) assembled together may constitute a case assembly.

[0076] The step (S10) of preparing the inner cell (100) may be the same as that for manufacturing a conventional pouch-type battery cell. That is, there is an advantage in that production facilities for manufacturing a conventional pouch-type battery cell can be used as is.

[0077] In the step (S20) of attaching the pad (400) to the inner cell (100), the pad (400) can be attached to both sides of the inner cell (100) in the thickness direction. As a result, the inner cell (100) and the pad (400) can be easily accommodated in the case assembly.

[0078] The step (S30) of accommodating the inner cell (100) with the pad (400) attached to the case assembly may include the step (S31) of assembling the first end cover (310) to the case body (201), the step (S32) of accommodating the inner cell (100) to the case body (201), the step (S33) of assembling the second end cover (320) to the first end cover (310) and / or the case body (201), and the step (S34) of joining the case cover (202) to the case body (201).

[0079] In the step (S31) of assembling the first end cover (310) to the case body (201), the first end cover (310) can be assembled to the end of the case body (201).

[0080] In the step (S32) of accommodating the inner cell (100) in the case body (201), the electrode lead (130) of the inner cell (100) may protrude outwardly from the first end cover (310). More specifically, a part of the electrode lead (130) may be positioned on the first groove (310a) formed in the first end cover (310), and another part may protrude outwardly from the first end cover (310). In addition, the pad (400) attached to one surface of the inner cell (100) may come into contact with the inner surface of the base portion (210) of the case body (201).

[0081] In the step (S33) of assembling the second end cover (320) to the first end cover (310) and / or the case body (201), the electrode lead (130) may protrude outwardly through a space between the first end cover (310) and the second end cover (320). More specifically, the electrode lead (130) may protrude outwardly through the first groove (310a) and / or the second groove (320a). In addition, the first end cover (310) and the second end cover (320) may be arranged to be in contact with each other.

[0082] In the step (S34) of attaching the case cover (202) to the case body (201), the pad (400) attached to the other surface of the inner cell (100) can come into contact with the inner surface of the cover portion (230) of the case cover (202).

[0083] Through this series of processes, the inner cell (100) can be easily accommodated within the case assembly. That is, there is an advantage in that the battery cell (100) can be easily manufactured using an existing pouch-type battery cell.

[0084] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0085] Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention but to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments.

[0086] The scope of protection of the present invention should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

[0087] [Explanation of symbols]

[0088] 10: Battery cell

[0089] 100: Inner Cell

[0090] 110: Electrode assembly

[0091] 120: Pouch-type outer material

[0092] 130: Electrode lead

[0093] 200: Case

[0094] 201: Case body

[0095] 202: Case cover

[0096] 210: Bass section

[0097] 220: Side section

[0098] 230: Cover

[0099] 300: End Cover

[0100] 310: First End Cover

[0101] 320: Second End Cover

[0102] 400: Pad

Claims

1. An inner cell in which the electrode assembly is housed in a pouch-shaped outer shell; A case that accommodates the inner cell and has higher rigidity than the outer material; An end cover covering the end of the case and having an insulating material; and A battery cell including a pad that is in close contact between the inner surface of the case and the outer surface of the inner cell and is elastically deformable.

2. In paragraph 1, A battery cell in which the electrode lead of the inner cell extends toward the end of the case and protrudes outward from the end cover.

3. In paragraph 1, The above pad is a battery cell attached to the outer surface of the inner cell.

4. In paragraph 1, The above pad is a battery cell having a pair of pads arranged on both sides in the thickness direction of the inner cell.

5. In paragraph 1, A battery cell having a groove formed in the end cover through which the electrode lead of the inner cell passes.

6. In paragraph 1, The above end cover, A first end cover covering a portion of the end of the case; and A second end cover covering another part of the end of the case and in contact with the first end cover, The electrode lead of the inner cell is a battery cell that protrudes outside the case through the space between the first end cover and the second end cover.

7. In paragraph 6, A battery cell having a groove formed in at least one of the first end cover and the second end cover through which the electrode lead passes.

8. In paragraph 1, In the above case, a battery cell in which a single inner cell is accommodated.

9. In paragraph 1, The above case is, A base portion located on one side of the thickness direction of the inner cell; A pair of side portions facing each other in the width direction of the inner cell and connected to the base portion; and A battery cell comprising a cover portion that faces the base portion with the inner cell interposed therebetween and connects the pair of side portions.

10. A step of preparing an inner cell in which the electrode assembly is accommodated in a pouch-shaped outer material; A step of attaching a pad having an elastically deformable material to the outer surface of the inner cell; and A step of accommodating the inner cell with the pad attached thereto in a case assembly, The above case assembly, A case that accommodates the inner cell and has higher rigidity than the outer material, and is separable into a case body and a case cover; and A method for manufacturing a battery cell, comprising an end cover having an insulating material and covering an end of the case.

11. In paragraph 10, The step of accommodating the inner cell in the case assembly is: A step of assembling a first end cover to the above case body; A step of accommodating the inner cell in the case body, wherein the electrode lead of the inner cell protrudes outward from the first end cover; A step of assembling a second end cover to the first end cover and / or the case body, wherein the electrode lead protrudes outwardly through a gap between the first end cover and the second end cover; and A method for manufacturing a battery cell, comprising the step of bonding a case cover to the case body.

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