Secondary battery and method for manufacturing secondary battery

Abstract

A secondary battery according to an embodiment of the present invention may comprise: a pouch-type case having an open portion which is open between a pair of case units; an electrode assembly inserted into the case through the open portion; and a sealing member provided to cover the open portion and seal the case.

Description

Secondary battery and method for manufacturing secondary battery

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0099212, filed July 28, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a secondary battery and a method for manufacturing a secondary battery.

[0005]

[0006] To address accelerating environmental pollution and the energy shortage caused by the depletion of petroleum resources, research and development are underway on power generation based on eco-friendly energy sources. In particular, research on secondary batteries is actively underway, exploring various aspects of secondary batteries, including their materials, structure, processes, and stability.

[0007] The internal electrode assembly of a secondary battery may be enclosed in a case. The case may take various forms, including a pouch-shaped case. In the case of a pouch-shaped case, a process may be performed to form a flat pouch sheet so that the electrode assembly can be embedded therein.

[0008] Conventional pouch-type cases, which are constructed of multiple layers, have limitations in their elongation due to pressure and heating, which limits the thickness and size of the secondary battery or case. If manufacturing limitations in the secondary battery or case occur during the manufacturing process, it can be difficult to improve the energy density of the secondary battery and its performance can also be limited.

[0009]

[0010] The problem to be solved by the present invention is to provide a secondary battery and a method for manufacturing a secondary battery that can be efficiently produced while increasing energy density by improving the limitations in manufacturing a secondary battery or case.

[0011]

[0012] A secondary battery according to one embodiment of the present invention may include a pouch-shaped case having an opening between a pair of case units, an electrode assembly inserted into the case through the opening, and a sealing member provided to cover the opening and seal the case.

[0013] A method for manufacturing a secondary battery according to an embodiment of the present invention may include a preparation step of preparing a case sheet having a recessed portion sunk to a predetermined depth, a unit forming step of cutting the case sheet to form case units, and a secondary battery forming step of forming a secondary battery having an electrode assembly built in using the case units.

[0014]

[0015] According to a preferred embodiment of the present invention, the numerical limitations in manufacturing a secondary battery or case can be improved.

[0016] According to a preferred embodiment of the present invention, the energy density of a secondary battery can be improved.

[0017]

[0018] Figure 1 is a schematic diagram showing a case sheet according to a first embodiment of the present invention.

[0019] Fig. 2 is a side view showing a case sheet according to the first embodiment of the present invention as viewed from one direction.

[0020] Figure 3 is a perspective view showing a pouch-type case according to the first embodiment of the present invention.

[0021] Fig. 4 is a side view showing a pouch-shaped case according to the first embodiment of the present invention as viewed from one direction.

[0022] Figure 5 is a plan view showing a secondary battery according to the first embodiment of the present invention.

[0023] Figure 6 is a side view showing a secondary battery according to the first embodiment of the present invention viewed from another direction.

[0024] FIG. 7 is a side view showing a secondary battery sealed with a sealing member according to a first embodiment of the present invention, viewed from one direction.

[0025] Fig. 8 is a perspective view showing a pouch-type case according to a second embodiment of the present invention.

[0026] Fig. 9 is a side view showing a pouch-shaped case according to a second embodiment of the present invention as viewed from one direction.

[0027] Figure 10 is a plan view showing a secondary battery according to a second embodiment of the present invention.

[0028] Fig. 11 is a side view showing a secondary battery according to a second embodiment of the present invention viewed from another direction.

[0029] FIG. 12 is a side view showing a secondary battery sealed with a sealing member according to a second embodiment of the present invention, viewed from one direction.

[0030]

[0031] 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.

[0032] 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.

[0033] 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.

[0034] FIG. 1 is a schematic diagram showing a case sheet according to a first embodiment of the present invention, and FIG. 2 is a side view showing a case sheet according to the first embodiment of the present invention as viewed from one direction.

[0035] The case sheet (1) can form a case (10) that forms the outer surface of a secondary battery (100) described later.

[0036] The case sheet (1) may have a recessed portion (2) formed therein. The recessed portion (2) may be formed to be recessed to a predetermined depth. The recessed depth of the recessed portion (2) may be determined according to the size of the electrode assembly (60) to be placed inside the secondary battery (100).

[0037] A pair of case units (11, 12) each having a recessed portion (2) formed by cutting a case sheet (1) can be formed. However, this is not limited thereto, and a recessed portion (2) recessed to a predetermined depth may be formed in at least one of the pair of case units, and the other may be formed as a flat surface.

[0038] The case sheet (1) may be prepared in a rolled form to be supplied to the manufacturing process of a secondary battery, but is not limited thereto.

[0039] The manufacturing method of a secondary battery (100) may include a preparatory step of preparing a case sheet (1).

[0040] Fig. 3 is a perspective view showing a pouch-type case according to a first embodiment of the present invention, and Fig. 4 is a side view showing a pouch-type case according to the first embodiment of the present invention as viewed from one direction. The description of the above-described embodiment can be applied to the present embodiment in the same or similar manner.

[0041] The manufacturing method of a secondary battery (100) may include a unit formation step.

[0042] The unit formation step may be a step of forming case units (11, 12) by cutting the case sheet (1). For example, the case sheet (1) may be cut to form a first case unit (11) and a second case unit (12). The first case unit (11) and the second case unit (12) may be connected through a connecting portion (30), but are not limited thereto and may also be embodiments in which they are separated.

[0043] The manufacturing method of a secondary battery (100) may include a secondary battery forming step.

[0044] The secondary battery formation step may be a step of forming a secondary battery (100) with an electrode assembly (60) built in using case units (11, 12).

[0045] The secondary battery forming step may include a step of overlapping case units (11, 12) so that an opening (20) is formed. The case units (11, 12) may overlap to form a case (10).

[0046] The case (10) may include a pair of case units (11, 12). For example, the case (10) may include a first case unit (11) and a second case unit (12). The first case unit (11) and the second case unit (12) may be overlapped so as to face each other.

[0047] The case (10) may include a connecting portion (30). For example, the connecting portion (30) may be foldable and may connect a pair of case units (11, 12).

[0048] A pair of case units (11, 12) may be overlapped so as to face each other, so that an opening (20) may be formed on one side of the case (10). For example, when the connecting portion (30) is folded so that the first case unit (11) and the second case unit (12) face each other, the provided recessed portions (2) of each of the first case unit (11) and the second case unit (12) may form an opening (20).

[0049] The opening (20) may be polygonal in shape. For example, the recessed portion (2) formed in the case sheet (1) may be recessed in a cross-section in the shape of a polygon (e.g., a rectangle, a trapezoid). When the first case unit (11) and the second case unit (12) are overlapped so as to face each other, a polygonal opening (20) may be formed by the recessed portion (2) formed in at least one of the first case unit (11) and the second case unit (12).

[0050] Fig. 5 is a plan view showing a secondary battery according to a first embodiment of the present invention, Fig. 6 is a side view showing a secondary battery according to the first embodiment of the present invention when viewed from another direction, and Fig. 7 is a side view showing a secondary battery sealed with a sealing member according to the first embodiment of the present invention when viewed from one direction. The description of the above-described embodiment can be applied to the present embodiment in the same or similar manner.

[0051] The secondary battery forming step may include a step of placing an electrode assembly (60). For example, the secondary battery forming step may include a step of inserting the electrode assembly (60) between case units (11, 12) through an opening (20).

[0052] The secondary battery formation step may include a sealing step. For example, the sealing step may be a step of sealing the opening (20) using a sealing member (80).

[0053] A secondary battery (100) may include a pouch-shaped case (10) having an opening (20) between a pair of case units (11, 12), an electrode assembly (60) inserted into the case (10) through the opening (20), and a sealing member (80) provided to cover the opening (20) and seal the case (10).

[0054] The sealing member (80) may include a metal member. The sealing member (80) may be a metal member having a cooling effect. The shape of the sealing member (80) may correspond to the shape of the opening (20). For example, the metal member (80) may have a shape corresponding to the shape of the opening (20) so that it can be inserted into the opening (20) to seal the case (10). However, the above-described shape of the metal member (80) is an example and is not limited thereto.

[0055] When the sealing member (80) is composed of a metal member having a cooling effect, cooling of heat generated inside the secondary battery (100) can be performed.

[0056] When a secondary battery (100) is manufactured using a case sheet (1) prepared by forming a pre-depressed portion (2), electrode assemblies (60) of various sizes can be accommodated depending on the depth of the depression (2). In other words, when pre-forming the depression (2) of the case sheet (1), the forming can be performed taking into consideration the size of the electrode assembly (60) to be accommodated. In this case, when pre-forming the depth of the depression (2) depending on the size of the electrode assembly (60), the energy density of the secondary battery (100) can be effectively improved while improving the numerical limitations of forming by pressurization and heating in the manufacture of the secondary battery or the case.

[0057] Fig. 8 is a perspective view showing a pouch-type case according to a second embodiment of the present invention, and Fig. 9 is a side view showing a pouch-type case according to the second embodiment of the present invention as viewed from one direction. The description of the above-described embodiment can be applied to the present embodiment in the same or similar manner.

[0058] The case (10a) may include a pair of case units (11a, 12a). For example, the first case unit (11a) and the second case unit (12a) may be overlapped so as to face each other, thereby forming openings (20a) on both sides. In this case, the first case unit (11a) and the second case unit (12a) may be distinct case units that are not connected via a connecting portion (e.g., a connecting portion (30)).

[0059] The electrode assembly (60a) can be inserted through one of the openings (20a) formed on both sides of the case (10a).

[0060] A plurality of sealing members (80a) may be provided to cover a plurality of openings (20a). For example, the sealing members (80a) may cover the openings (20a) formed on both sides of the case (10a).

[0061] The openings (20a) formed on both sides of the case (10a) may each have a polygonal shape.

[0062] Fig. 10 is a plan view showing a secondary battery according to a second embodiment of the present invention, Fig. 11 is a side view showing a secondary battery according to the second embodiment of the present invention when viewed from another direction, and Fig. 12 is a side view showing a secondary battery sealed with a sealing member according to the second embodiment of the present invention when viewed from one direction. The description of the above-described embodiment can be applied to the present embodiment in the same or similar manner.

[0063] A secondary battery (100a) may include a pouch-shaped case (10a) having an open portion (20a) between a pair of case units (11a, 12a), an electrode assembly (60a) inserted into the case (10a) through the open portion (20a), and a sealing member (80a) provided to cover the open portion (20a) and seal the case (10a).

[0064] Openings (20a) can be formed on both sides of the case (10a). A plurality of sealing members (80a) can be provided to cover a plurality of openings (20a) and inserted into the openings (20a).

[0065] According to the above, it is possible to effectively improve the energy density of a secondary battery (100) while improving the numerical limitations of forming by pressurization and heating in the production of a secondary battery or case.

[0066] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various embodiments are possible within the scope equivalent to the technical idea of ​​the present invention and the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0067] [Explanation of symbols]

[0068] 1: Case sheet

[0069] 2: Depression

[0070] 10, 10a: Pouch-type case

[0071] 11, 11a: 1st case unit

[0072] 12, 12a: Second case unit

[0073] 20, 20a: Opening

[0074] 30, 30a: Connection

[0075] 40, 40a: 1st sealing section

[0076] 50, 50a: Second sealing section

[0077] 60, 60a: Electrode assembly

[0078] 70, 70a: Electrode leads

[0079] 80, 80a: Sealing member

[0080] 100, 100a: secondary battery

Claims

1. A pouch-shaped case having an open portion between a pair of case units; An electrode assembly inserted into the case through the opening; and A secondary battery comprising a sealing member configured to cover the opening and seal the case.

2. In claim 1, At least one of the above pair of case units, A secondary battery having a recessed portion sunk to a predetermined depth.

3. In claim 2, The above case is, a pair of case units facing each other; and A secondary battery comprising a connecting portion that is folded and connects the pair of case units.

4. In claim 1, A secondary battery in which the above pair of case units are overlapped so as to face each other and the above openings are formed on both sides.

5. In claim 4, The above sealing member, A secondary battery, provided in multiple numbers to cover multiple openings.

6. In claim 1, The above opening is, A secondary battery in the shape of a polygon.

7. In claim 1, The above sealing member, A secondary battery comprising a metal member having a cooling effect.

8. In claim 7, The shape of the above metal member is: A secondary battery corresponding to the shape of the above opening.

9. In claim 7, The above metal member, A secondary battery inserted into the above opening.

10. Preparatory step of preparing a case sheet with a recessed portion sunk to a predetermined depth; A unit forming step of forming case units by cutting the case sheet; and A method for manufacturing a secondary battery, comprising a secondary battery forming step of forming a secondary battery having an electrode assembly built in using the above case units.

11. In claim 10, The above secondary battery formation step is, A step of arranging the case units so that they overlap each other so that an opening is formed; and A method for manufacturing a secondary battery, comprising the step of inserting an electrode assembly between the case units through the opening.

12. In claim 11, The above secondary battery formation step is, A secondary battery manufacturing method further comprising a sealing step of sealing the above-mentioned opening using a sealing member.

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