Secondary battery and method of manufacturing secondary battery

Abstract

A secondary battery according to one embodiment of the present invention may include a pouch-type 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.

Description

Technology Field

[0001] The present invention relates to a secondary battery and a method for manufacturing a secondary battery. Background Technology

[0002] Research and development on power generation based on eco-friendly energy sources are underway to address the problem of accelerating environmental pollution and the energy source shortage resulting from the depletion of petroleum resources. In particular, research on secondary batteries is actively progressing, with studies being conducted on various aspects such as materials, structure, processes, and stability.

[0003] The internal electrode assembly of a secondary battery can be encased in a case. The case may take various forms, including pouch-type cases. In the case of a pouch-type case, a flat pouch sheet may undergo a forming process to accommodate the electrode assembly.

[0004] According to the prior art, since pouch-type cases have a structure in which multiple layers are stacked, there is a limit to elongation caused by pressure and heating, which limits the thickness or size in the production of secondary batteries or cases. If there are limitations in the production of secondary batteries or cases during the process stage, it may be difficult to improve the energy density of the secondary battery and there may also be limitations on performance. The problem to be solved

[0005] The problem that the present invention aims to solve is to provide a secondary battery and a method for manufacturing a secondary battery that enable efficient production while increasing energy density by improving the limitations in the production of the secondary battery or case. means of solving the problem

[0006] A secondary battery according to one embodiment of the present invention may include a pouch-type 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.

[0007] A method for manufacturing a secondary battery according to one embodiment of the present invention may include a preparation step of preparing a case sheet having a recessed portion formed to a predetermined depth, a unit formation step of cutting the case sheet to form case units, and a secondary battery formation step of forming a secondary battery having an electrode assembly embedded therein using the case units. Effects of the invention

[0008] According to a preferred embodiment of the present invention, numerical limitations in the production of a secondary battery or case can be improved.

[0009] According to a preferred embodiment of the present invention, the energy density of a secondary battery can be improved. Brief explanation of the drawing

[0010] FIG. 1 is a schematic diagram showing a case sheet according to a first embodiment of the present invention. FIG. 2 is a side view showing a case sheet according to a first embodiment of the present invention as seen from one direction. FIG. 3 is a perspective view showing a pouch-type case according to a first embodiment of the present invention. FIG. 4 is a side view showing a pouch-type case according to a first embodiment of the present invention as seen from one direction. 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 a first embodiment of the present invention viewed from a different direction. 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. FIG. 8 is a perspective view showing a pouch-type case according to a second embodiment of the present invention. FIG. 9 is a side view showing a pouch-type case according to a second embodiment of the present invention as seen from one direction. 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 a second embodiment of the present invention viewed from a different direction. 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. Specific details for implementing the invention

[0011] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0012] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.

[0013] Furthermore, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0014] 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 a first embodiment of the present invention viewed from one direction.

[0015] The case sheet (1) can form a case (10) that forms the outer periphery of the secondary battery (100) described later.

[0016] The case sheet (1) may have a recess (2) formed therein. The recess (2) may be formed to be recessed to a predetermined depth. The depth of the recess (2) may be determined to match the size of the electrode assembly (60) to be placed inside the secondary battery (100).

[0017] A pair of case units (11, 12) with a recessed portion (2) formed by cutting the case sheet (1) can be formed. However, this is not limited thereto, and a recessed portion (2) with a predetermined depth may be formed in only at least one of the pair of case units, while the other may be formed as a flat surface.

[0018] 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.

[0019] The method for manufacturing a secondary battery (100) may include a preparation step of preparing a case sheet (1).

[0020] 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 a first embodiment of the present invention viewed from one direction. The description of the above-described embodiment may be applied to the present embodiment in the same or similar manner.

[0021] The method for manufacturing a secondary battery (100) may include a unit forming step.

[0022] 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 part (30), but are not limited thereto and may be an embodiment in which they are separated.

[0023] The method for manufacturing a secondary battery (100) may include a secondary battery formation step.

[0024] The secondary battery formation step may be a step of forming a secondary battery (100) in which an electrode assembly (60) is embedded using case units (11, 12).

[0025] The secondary battery formation step may include a step of arranging case units (11, 12) so as to overlap each other to form an opening (20). The case units (11, 12) may overlap to form a case (10).

[0026] 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 to face each other.

[0027] The case (10) may include a connecting part (30). For example, the connecting part (30) may be foldable and may connect a pair of case units (11, 12).

[0028] A pair of case units (11, 12) may be overlapped to face each other so that an opening (20) may be formed on one side of the case (10). For example, when the connecting part (30) is folded so that the first case unit (11) and the second case unit (12) face each other, the provided recess (2) of the first case unit (11) and the second case unit (12) may form an opening (20).

[0029] The opening (20) may be in the shape of a polygon. For example, the recess (2) formed in the case sheet (1) may have a cross-section that is recessed in the shape of a polygon (e.g., rectangle, trapezoid). When the first case unit (11) and the second case unit (12) are overlapped to face each other, the polygonal opening (20) may be formed by the recess (2) formed in at least one of the first case unit (11) and the second case unit (12).

[0030] 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 a first embodiment of the present invention viewed from a different direction, and 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. The description of the above-described embodiment may be applied to the present embodiment in the same or similar manner.

[0031] The secondary battery formation step may include a step of placing an electrode assembly (60). For example, the secondary battery formation step may include a step of inserting the electrode assembly (60) between case units (11, 12) through an opening (20).

[0032] 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).

[0033] The secondary battery (100) may include a pouch-type case (10) having an opening (20) open 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).

[0034] 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 description regarding the shape of the metal member (80) is an example and is not limited thereto.

[0035] 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.

[0036] When manufacturing a secondary battery (100) using a case sheet (1) prepared with a pre-formed recessed portion (2), electrode assemblies (60) of various sizes can be accommodated according to the depth of the recessed portion (2). In other words, when pre-forming the recessed portion (2) of the case sheet (1), the forming can be done considering the size of the electrode assembly (60) to be accommodated. In this case, if the depth of the recessed portion (2) is pre-formed according to the size of the electrode assembly (60), the energy density of the secondary battery (100) can be effectively improved, while also improving the numerical limit of forming by pressure and heating in the production of the secondary battery or case.

[0037] 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 a second embodiment of the present invention viewed from one direction. The description of the above-described embodiment may be applied to the present embodiment in the same or similar manner.

[0038] 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 to face each other so that an opening (20a) is formed 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 through a connecting part (e.g., a connecting part (30)).

[0039] The electrode assembly (60a) can be inserted through one of the openings (20a) formed on both sides of the case (10a).

[0040] A plurality of sealing members (80a) may be provided to cover a plurality of openings (20a). For example, the sealing members (80a) may cover openings (20a) formed on both sides of the case (10a).

[0041] The openings (20a) formed on both sides of the case (10a) may each be polygonal in shape.

[0042] 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 a second embodiment of the present invention viewed from a different direction, and 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. The description of the above-described embodiment may be applied to the present embodiment in the same or similar manner.

[0043] The secondary battery (100a) may include a pouch-type case (10a) having an opening (20a) open between a pair of case units (11a, 12a), an electrode assembly (60a) inserted into the case (10a) through the opening (20a), and a sealing member (80a) provided to cover the opening (20a) and seal the case (10a).

[0044] Openings (20a) may be formed on both sides of the case (10a). A plurality of sealing members (80a) may be provided to cover a plurality of openings (20a) and inserted into the openings (20a).

[0045] According to the above description, the energy density of the secondary battery (100) can be effectively improved, while also improving the numerical limit of forming by pressurization and heating in the production of the secondary battery or case.

[0046] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0047] 1: Case Sheet 2: Depression 10, 10a: Pouch-type case 11, 11a: First case unit 12, 12a: Second case unit 20, 20a: Opening 30, 30a: Connection part 40, 40a: First sealing part 50, 50a: Second sealing part 60, 60a: Electrode assembly 70, 70a: Electrode leads 80, 80a: Sealing member 100, 100a: Secondary battery

Claims

Claim 1 A secondary battery comprising: a pair of case units facing each other; a recess formed to be recessed to a predetermined depth in at least one of the pair of case units; a pouch-type case having an opening formed in at least one of the pair of case units such that one end is in communication with the end of the recess and the other end is in communication with the outside; an electrode assembly inserted into the case through the opening while the pair of case units are overlapped to face each other; and a sealing member provided to cover the opening and seal the case, wherein the recess comprises a bottom portion facing the electrode assembly, a first side wall portion connected to one end of the bottom portion to form a first intersection line together with the bottom portion, and a second side wall portion connected to the other end of the bottom portion to form a second intersection line together with the bottom portion. Claim 2 delete Claim 3 A secondary battery according to claim 1, wherein the pouch-type case comprises a connecting portion that is folded to connect the pair of case units. Claim 4 A secondary battery according to claim 1, wherein the pair of case units are overlapped to face each other so as to form the openings on both sides. Claim 5 A secondary battery according to claim 4, wherein the sealing member is provided in a plurality to cover a plurality of openings. Claim 6 A secondary battery according to claim 1, wherein the opening is in the shape of a polygon. Claim 7 A secondary battery according to claim 1, wherein the sealing member comprises a metal member having a cooling effect. Claim 8 In claim 7, the shape of the metal member corresponds to the shape of the opening, a secondary battery. Claim 9 In claim 7, the metal member is a secondary battery inserted into the opening. Claim 10 A method for manufacturing a secondary battery, comprising: a preparation step of preparing a pouch case sheet having a recessed portion formed to a predetermined depth; a unit formation step of cutting the pouch case sheet to form case units; and a secondary battery formation step of forming a secondary battery having an electrode assembly embedded therein using the case units, wherein the secondary battery formation step comprises: a step of arranging the case units in an overlapping manner so as to form an opening; and a step of inserting an electrode assembly between the case units through the opening, wherein one end of the opening is in communication with the end of the recessed portion and the other end is in communication with the outside, and the recessed portion comprises a bottom portion facing the electrode assembly, a first side wall portion connected to one side end of the bottom portion to form a first intersection line together with the bottom portion, and a second side wall portion connected to the other side end of the bottom portion to form a second intersection line together with the bottom portion. Claim 11 delete Claim 12 A method for manufacturing a secondary battery according to claim 10, wherein the secondary battery forming step further comprises a sealing step of sealing the opening using a sealing member.

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