Electrode assembly and method for manufacturing the same

Abstract

The technical concept of the present disclosure provides an electrode assembly comprising: a separation membrane sheet including a folding portion folded in a zigzag manner to define a plurality of vertically separated accommodation spaces and a cover portion extending from the folding portion; and a cell structure including a first electrode and a second electrode, which is housed in the plurality of accommodation spaces of the separation membrane sheet, wherein the cover portion of the separation membrane sheet includes a first side cover portion that covers a first side surface of the cell structure, and the first side cover portion includes a first through-hole that communicates with at least one of the plurality of accommodation spaces of the separation membrane sheet.

Description

Technical Field

[0001] The present disclosure relates to an electrode assembly and a method for manufacturing the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0033295 filed on March 8, 2024, and all the contents disclosed in the document of the Korean patent application are included as part of this specification.

Background Art

[0003] Unlike a primary battery, a secondary battery can be charged and discharged multiple times. Secondary batteries are widely used as an energy source for various cordless devices such as handsets, notebook computers, and cordless vacuum cleaners. Generally, a secondary battery has a structure in which an electrode assembly having a structure in which an electrode and a separator are laminated is built into a battery case such as a pouch. When a gas trap occurs in the electrode assembly, there is a problem that an inactive region is formed on the electrode surface and lithium is deposited during charge and discharge.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technical problem to be achieved by the present disclosure is to provide an electrode assembly and a method for manufacturing the same.

Means for Solving the Problems

[0005] To solve the above-mentioned problems, the technical concept of the present disclosure provides an electrode assembly comprising: a separation membrane sheet including a folding portion folded in a zigzag manner to define a plurality of vertically separated accommodation spaces and a cover portion extending from the folding portion; and a cell structure including a first electrode and a second electrode, which is housed in the plurality of accommodation spaces of the separation membrane sheet, wherein the cover portion of the separation membrane sheet includes a first side cover portion that covers a first side surface of the cell structure, and the first side cover portion includes a first through-hole that communicates with at least one of the plurality of accommodation spaces of the separation membrane sheet.

[0006] In an exemplary embodiment, the cover portion of the separation membrane sheet further includes a second side cover portion that covers a second side of the cell structure opposite to the first side of the cell structure, and the second side cover portion includes a second through-hole that communicates with at least one of the plurality of containment spaces of the separation membrane sheet.

[0007] In an exemplary embodiment, the cover portion of the separation membrane sheet further includes a third side cover portion that contacts the first side cover portion, and the third side cover portion includes a third through hole that communicates with the first through hole.

[0008] In an exemplary embodiment, the cover portion of the separation membrane sheet further includes a first bottom cover portion extending between the first side cover portion and the second side cover portion and covering the bottom surface of the cell structure, and a top cover portion extending between the second side cover portion and the third side cover portion and covering the top surface of the cell structure.

[0009] In an exemplary embodiment, the cover portion of the separation membrane sheet further includes a second bottom cover portion connected to the third side cover portion, and the second bottom cover portion is fixed to the first bottom cover portion.

[0010] In an exemplary embodiment, the separation membrane sheet is characterized by being a single sheet.

[0011] In an exemplary embodiment, the cell structure includes a plurality of unit cells separated from each other by the folding portion of the separation membrane sheet, and each of the plurality of unit cells includes at least one of the first electrode and the second electrode.

[0012] In an exemplary embodiment, the cell structure is characterized in that the first electrode is a single sheet extending in a zigzag pattern along the folding portion of the separation membrane sheet.

[0013] In an exemplary embodiment, the cell structure is characterized in that the second electrode is a single sheet extending in a zigzag pattern along the first electrode.

[0014] To solve the above-mentioned problems, the technical concept of the present disclosure provides a method for manufacturing an electrode assembly, comprising the steps of: preparing a structure including a separation membrane sheet and a cell structure - the cell structure including a first electrode and a second electrode, and the separation membrane sheet including a folding portion defining a plurality of housing spaces for housing the cell structure and a cover portion connected to the folding portion; a first punching step of forming a first through hole in a first side cover portion of the cover portion of the separation membrane sheet; and a first winding step of winding the cover portion of the separation membrane sheet so that the first side cover portion of the separation membrane sheet faces a first side surface of the cell structure.

[0015] In an exemplary embodiment, the first winding step further includes winding the cover portion of the separation membrane sheet so that the first bottom cover portion of the cover portion of the separation membrane sheet, which is connected to the first side cover portion of the separation membrane sheet, faces the bottom surface of the cell structure.

[0016] In an exemplary embodiment, the present invention further includes a second punching step of forming a second through-hole in the second side cover portion of the cover portion of the separation membrane sheet, and a second winding step of winding the cover portion of the separation membrane sheet so that the second side cover portion of the separation membrane sheet faces the second side surface of the cell structure.

[0017] In an exemplary embodiment, the second winding step further includes winding the cover portion of the separation membrane sheet so that the top cover portion of the cover portion of the separation membrane sheet, which is connected to the second side cover portion of the separation membrane sheet, faces the upper surface of the cell structure.

[0018] In an exemplary embodiment, the method further includes a third punching step of forming a third through-hole in the third side cover portion of the cover portion of the separation membrane sheet, and a third winding step of winding the cover portion of the separation membrane sheet so that the third side cover portion of the separation membrane sheet contacts the first side cover portion of the cover portion of the separation membrane sheet, wherein the first through-hole provided in the first side cover portion of the separation membrane sheet is aligned with the third through-hole provided in the third side cover portion of the separation membrane sheet.

[0019] In an exemplary embodiment, the first winding step further includes winding the cover portion of the separation membrane sheet so that the first bottom cover portion of the cover portion of the separation membrane sheet, which is connected to the first side cover portion of the separation membrane sheet, faces the bottom surface of the cell structure, and the third winding step further includes winding the cover portion of the separation membrane sheet so that the second bottom cover portion of the cover portion of the separation membrane sheet, which is connected to the third side cover portion of the separation membrane sheet, contacts the first bottom cover portion of the separation membrane sheet. [Effects of the Invention]

[0020] According to an exemplary embodiment, since the separation membrane sheet of the electrode assembly includes gas discharge holes for discharging the gas inside the electrode assembly, the gas inside the electrode assembly can be quickly discharged to the outside of the electrode assembly during the degassing process, and the generation of gas traps inside the electrode assembly can be prevented or suppressed. Thereby, it is possible to prevent capacity reduction, increase in cell resistance, lithium precipitation, etc. due to gas traps inside the electrode assembly, and ultimately improve the reliability of the secondary battery including the electrode assembly.

[0021] According to an exemplary embodiment, after the punching process of forming through holes in the cover portion of the separation membrane sheet is completed, by performing a winding process of winding up the cover portion of the separation membrane sheet, it is possible to prevent damage to the unit cell during the punching process.

[0022] The effects obtained from the exemplary embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those having ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following description. That is, the unintended effects associated with implementing the exemplary embodiments of the present disclosure can also be derived by those having ordinary knowledge in the technical field from the exemplary embodiments of the present disclosure.

Brief Description of the Drawings

[0023] [Figure 1] It is a perspective view showing an electrode assembly according to an exemplary embodiment. [Figure 2] It is a cross-sectional view showing an electrode assembly according to an exemplary embodiment. [Figure 3] It is a cross-sectional view showing a part of the cell structure of an electrode assembly according to an exemplary embodiment. [Figure 4] It is a flowchart showing a manufacturing method of an electrode assembly according to an exemplary embodiment. [Figure 5] It is a drawing showing a manufacturing method of an electrode assembly according to an exemplary embodiment. [Figure 6a]It is a drawing showing a method for manufacturing an electrode assembly according to an exemplary embodiment. [Figure 6b] It is a drawing showing a method for manufacturing an electrode assembly according to an exemplary embodiment. [Figure 7] It is a drawing showing a method for manufacturing an electrode assembly according to an exemplary embodiment. [Figure 8a] It is a drawing showing a method for manufacturing an electrode assembly according to an exemplary embodiment. [Figure 8b] It is a drawing showing a method for manufacturing an electrode assembly according to an exemplary embodiment. [Figure 9] It is a drawing showing a method for manufacturing an electrode assembly according to an exemplary embodiment. [Figure 10a] It is a drawing showing a method for manufacturing an electrode assembly according to an exemplary embodiment. [Figure 10b] It is a drawing showing a method for manufacturing an electrode assembly according to an exemplary embodiment. [Figure 11] It is a drawing showing a method for manufacturing an electrode assembly according to an exemplary embodiment. <000011 > [Figure 12] It is a cross-sectional view showing a method for manufacturing an electrode assembly according to an exemplary embodiment. [Figure 13] It is a cross-sectional view showing an electrode assembly according to an exemplary embodiment. [Figure 14] It is a cross-sectional view showing an electrode assembly according to an exemplary embodiment.

Embodiments for Carrying Out the Invention

[0024] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. On the premise that terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings, they can be construed as meanings and concepts that conform to the technical idea of the present disclosure based on the principle that the inventor can appropriately define the concept of the terms in order to explain his own invention in the best way.

[0025] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the disclosure and do not represent the entire technical concept of the disclosure. As a result, there may be a variety of equivalents and modifications that can be substituted for them at the time of filing.

[0026] Furthermore, if it is determined that a specific description of a relevant publicly known configuration or function in this disclosure would obscure the gist of this disclosure, such detailed description will be omitted.

[0027] Since embodiments of this disclosure are provided to explain the disclosure more fully to a person of ordinary skill, the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown schematically for the sake of clarity. Accordingly, the sizes and proportions of each component do not fully reflect their actual sizes and proportions.

[0028] (First Embodiment) Figure 1 is a perspective view showing an electrode assembly 100 according to an exemplary embodiment. Figure 2 is a cross-sectional view showing an electrode assembly 100 according to an exemplary embodiment. Figure 3 is a cross-sectional view showing a part of the cell structure 110 of the electrode assembly 100 according to an exemplary embodiment.

[0029] Referring to Figures 1 to 3, the electrode assembly 100 may include a cell structure 110 and a separation membrane sheet 120.

[0030] The cell structure 110 can constitute a secondary battery. The cell structure 110 may include a first electrode 191, a second electrode 192, or a laminate in which at least one first electrode 191 and at least one second electrode 192 are stacked vertically (e.g., in the Z direction) by a separator membrane 193. The separator membrane 193 may also be called an internal separator membrane. Here, the first electrode 191 and the second electrode 192 may have opposite polarities. For example, the first electrode 191 may be a positive electrode and the second electrode 192 may be a negative electrode. Or, the first electrode 191 may be a negative electrode and the second electrode 192 may be a positive electrode. The positive electrode may include a positive electrode current collector and a positive electrode active material. The negative electrode may include a negative electrode current collector and a negative electrode active material. The cell structure 110 may include an electrode tab 119 connected to at least one positive electrode and / or at least one negative electrode.

[0031] In exemplary embodiments, the cell structure 110 may include a plurality of unit cells 111 stacked vertically (e.g., in the Z direction). Each of the unit cells 111 may be a single first electrode 191, a single second electrode 192, or a laminate in which at least one first electrode 191 and at least one second electrode 192 are stacked vertically (e.g., in the Z direction) by a separation membrane 193. In exemplary embodiments, each unit cell 111 may include a bi-cell or a monocell. A bi-cell may have a stacked structure in which the two outermost electrodes are of the same type, such as positive electrode / separation membrane / negative electrode / separation membrane / positive electrode, positive electrode / separation membrane / negative electrode / separation membrane / negative electrode / separation membrane / negative electrode, negative electrode / separation membrane / positive electrode / separation membrane / negative electrode / separation membrane / negative electrode / separation membrane / negative electrode / separation membrane / negative electrode / separation membrane / negative electrode / separation membrane / negative electrode A monocell can have a layered structure in which the two outermost electrodes are of different types, such as positive electrode / separation membrane / negative electrode, positive electrode / separation membrane / negative electrode / separation membrane / positive electrode / separation membrane / negative electrode.

[0032] The unit cell 111 can generally have a flat shape extending in a first horizontal direction (e.g., the X direction) and a second horizontal direction (e.g., the Y direction). The unit cell 111 can have an opposite top and bottom surface in the vertical direction (e.g., the Z direction), a first and second side surface opposite in the first horizontal direction (e.g., the X direction), and a front and rear surface opposite in the second horizontal direction (e.g., the Y direction). Electrode tabs 119 can be provided on the front and / or rear surface of the unit cell 111. The top and bottom surfaces of the unit cell 111 can be planes extending in the first horizontal direction (e.g., the X direction) and the second horizontal direction (e.g., the Y direction), respectively, and can contact the separation membrane sheet 120. In this case, the cell structure 110 may have opposite top and bottom surfaces in the vertical direction (e.g., Z direction), opposite first and second sides in the first horizontal direction (e.g., X direction), and opposite front and rear surfaces in the second horizontal direction (e.g., Y direction). The first side surface 1151 of the cell structure 110 may include the first sides of a plurality of unit cells 111, the second side surface 1153 of the cell structure 110 may include the second sides of a plurality of unit cells 111, the top surface 1154 of the cell structure 110 may include the top surface of the uppermost unit cell 111 among the plurality of unit cells 111, the bottom surface 1152 of the cell structure 110 may include the bottom surface of the lowermost unit cell 111 among the plurality of unit cells 111, the front surface of the cell structure 110 may include the front surfaces of a plurality of unit cells 111, and the rear surface of the cell structure 110 may include the rear surfaces of a plurality of unit cells 111. The unit cell 111 may have a minor axis parallel to a first horizontal direction (e.g., the X direction) and a major axis parallel to a second horizontal direction (e.g., the Y direction). That is, the length of the unit cell 111 along the first horizontal direction (e.g., the X direction) may be smaller than the length of the unit cell 111 along the second horizontal direction (e.g., the Y direction).

[0033] The separation membrane sheet 120 may include a folding portion 130 and a cover portion 140. The separation membrane sheet 120 may be a single sheet.

[0034] The folding section 130 can be folded in a zigzag pattern to define a plurality of storage spaces 131 separated in the vertical direction (e.g., the Z direction). A unit cell 111 can be placed in each of the plurality of storage spaces 131 of the folding section 130. The folding section 130 can enclose an individual unit cell 111, and a plurality of unit cells 111 can be separated from each other by the folding section 130. Two adjacent unit cells 111 of the plurality of unit cells 111 can be separated with a portion of the folding section 130 in between. The folding section 130 may cover the top, bottom, and one side of an individual unit cell 111, but not the other side, front, and rear of an individual unit cell 111. For example, the plurality of unit cells 111 may include unit cells 111 in odd-numbered layers and unit cells 111 in even-numbered layers. The folding portion 130 can extend along the bottom, first side, and top surfaces of each unit cell 111 in odd-numbered layers, and the second side, front, and rear surfaces of each unit cell 111 in odd-numbered layers may not be covered by the folding portion 130. The folding portion 130 can extend along the bottom, second side, and top surfaces of each unit cell 111 in even-numbered layers, and can extend along the first side, front, and rear surfaces of each unit cell 111 in even-numbered layers.

[0035] The cover portion 140 extends from the folding portion 130 and can be wound up to surround the cell structure 110 and the folding portion 130. The cover portion 140 can be wound up to surround the cell structure 110 and form an internal space that houses the cell structure 110. The cover portion 140 can be connected to the folding portion 130. For example, the folding portion 130 can be connected to the portion of the folding portion 130 that is in contact with the upper surface of the uppermost unit cell 111 and can be wound up to cover the first side surface 1151, bottom surface, second side surface, and top surface of the cell structure 110.

[0036] In an exemplary embodiment, the cover portion 140 may include a first side cover portion 141 facing the first side surface 1151 of the cell structure 110 and covering at least partially the first side surface 1151 of the cell structure 110, a first bottom cover portion 142 facing the bottom surface 1152 of the cell structure 110 and covering at least partially the bottom surface 1152 of the cell structure 110, a second side cover portion 143 facing the second side surface 1153 of the cell structure 110 and covering at least partially the second side surface 1153 of the cell structure 110, a top cover portion 144 facing the top surface 1154 of the cell structure 110 and covering at least partially the top surface 1154 of the cell structure 110, a third side cover portion 145 in contact with the first side cover portion 141 and covering at least partially the first side cover portion 141, and a second bottom cover portion 146 in contact with the first bottom cover portion 142. The second bottom cover portion 146 can be fixed to the first bottom cover portion 142 by tape 160. The first side cover portion 141, the first bottom cover portion 142, the second side cover portion 143, the top cover portion 144, the third side cover portion 145, and the second bottom cover portion 146 can be sequentially arranged between the folding portion 130 and the end of the separation membrane sheet 120.

[0037] The cover portion 140 of the separation membrane sheet 120 may include a gas discharge hole to connect the internal space of the cover portion 140, which houses the cell structure 110, to the external space outside the cover portion 140. In an exemplary embodiment, the first side cover portion 141 may include a first through hole 151, the second side cover portion 143 may include a second through hole 152, and the third side cover portion 145 may include a third through hole 153. The first through hole 151 of the first side cover portion 141, the second through hole 152 of the second side cover portion 143, and the third through hole 153 of the third side cover portion 145 can each communicate with at least one of a plurality of housing spaces 131 provided by the folding portion 130 of the separation membrane sheet 120. The first through-hole 151 of the first side cover portion 141, the second through-hole 152 of the second side cover portion 143, and the third through-hole 153 of the third side cover portion 145 can constitute gas discharge holes of the separation membrane sheet 120. The first through-hole 151 of the first side cover portion 141 can communicate with the third through-hole 153 of the third side cover portion 145. Gas around the electrode assembly 100 can be discharged to the outside of the electrode assembly 100 through the first through-hole 151 of the first side cover portion 141 and the third through-hole 153 of the third side cover portion 145, and can also be discharged to the outside of the electrode assembly 100 through the second through-hole 152 of the second side cover portion 143.

[0038] The first side cover portion 141 may include a plurality of first through holes 151. For example, the plurality of first through holes 151 may be arranged in a second horizontal direction (e.g., the Y direction). For example, the plurality of first through holes 151 may be arranged to have multiple rows and multiple columns. The second side cover portion 143 may include a plurality of second through holes 152. For example, the plurality of second through holes 152 may be arranged in a second horizontal direction (e.g., the Y direction). For example, the plurality of second through holes 152 may be arranged to have multiple rows and multiple columns. The third side cover portion 145 may include a plurality of third through holes 153. For example, the plurality of third through holes 153 may be arranged in a second horizontal direction (e.g., the Y direction). For example, the plurality of third through holes 153 may be arranged to have multiple rows and multiple columns.

[0039] To manufacture a secondary battery including the electrode assembly 100, a loading step of placing the electrode assembly 100 into a battery case such as a pouch, an electrolyte injection step of injecting electrolyte into the battery case, a charging and discharging step of the electrode assembly 100, a degassing step of removing internal gas from the electrode assembly 100, and a sealing step of sealing the battery case can be performed. If internal gas from the electrode assembly 100 is not removed during the degassing step, a gas trap will form inside the electrode assembly 100, and this gas trap will cause a decrease in capacity, an increase in cell resistance, lithium deposition, etc., reducing the reliability of the secondary battery.

[0040] According to an exemplary embodiment, the separation membrane sheet 120 of the electrode assembly 100 includes gas discharge holes for discharging gas from within the electrode assembly 100. This allows gas from within the electrode assembly 100 to be rapidly discharged to the outside of the electrode assembly 100 during the degassing process, preventing or suppressing the formation of gas traps within the electrode assembly 100. This prevents capacity reduction, increased cell resistance, lithium deposition, etc., caused by gas traps within the electrode assembly 100, ultimately improving the reliability of the secondary battery including the electrode assembly 100.

[0041] (Second Embodiment) Figure 4 is a flowchart illustrating a method for manufacturing the electrode assembly 100 according to an exemplary embodiment. Figures 5 to 11 are drawings illustrating a method for manufacturing the electrode assembly 100 according to an exemplary embodiment. Figures 5, 6a, 7, 8a, 9, 10a, and 11 are cross-sectional views illustrating the method for manufacturing the electrode assembly 100, while Figures 6b, 8b, and 10b are plan views illustrating the method for manufacturing the electrode assembly 100. The method for manufacturing the electrode assembly 100 shown in Figures 1 to 3 will be described below with reference to Figures 4 to 11.

[0042] Referring to Figure 5, a structure 100p is prepared, which includes a plurality of unit cells 111 and a separation membrane sheet 120 (S110). In the above structure 100p, the separation membrane sheet 120 may include a folding portion 130 that is folded in a zigzag pattern to surround each of the plurality of unit cells 111, and a cover portion 140 connected to the folding portion 130.

[0043] Referring to Figures 6a and 6b, the above structure (100p in Figure 5) is fed into a secondary battery manufacturing apparatus configured to perform a punching process on the cover portion 140 of the separation membrane sheet 120 and a winding process on the cover portion 140 of the separation membrane sheet 120. The secondary battery manufacturing apparatus may include a holder 210 configured to support the cell structure 110, a gripper 220 configured to grip and support the end of the cover portion 140 of the separation membrane sheet 120, and a cutter 230 configured to punch out the cover portion 140 of the separation membrane sheet 120. The holder 210 may include a holding block for gripping the cell structure 110 and an actuator for moving the holding block. The gripper 220 may include a gripper block for gripping the end of the cover portion 140 of the separation membrane sheet 120 and an actuator for moving the gripper block. The cutter 230 described above can be configured to cut the cover portion 140 of the separation membrane sheet 120 to form a through hole in the separation membrane sheet 120. In an exemplary embodiment, the cutter 230 may include at least one needle 231. The needle 231 can move to penetrate the cover portion 140 of the separation membrane sheet 120 to form a through hole in the cover portion 140 of the separation membrane sheet 120.

[0044] When the structure 100p is fed into the secondary battery manufacturing apparatus, the secondary battery manufacturing apparatus performs a first punching process to form a first through-hole 151 in the first side cover portion 141 of the separation membrane sheet 120 (S120).

[0045] In step S120 described above, the holder 210 can support the cell structure 110, and the gripper 220 can support the cover portion 140 of the separation membrane sheet 120. The gripper 220 can support the cover portion 140 of the separation membrane sheet 120 such that the first side cover portion 141 of the separation membrane sheet 120 does not cover the first side surface 1151 of the cell structure 110. For example, the gripper 220 can support the cover portion 140 of the separation membrane sheet 120 such that the first side cover portion 141 of the separation membrane sheet 120 extends in a first horizontal direction (e.g., the X direction).

[0046] In step S120 described above, while the gripper 220 supports the cover portion 140 of the separation membrane sheet 120, the cutter 230 can form a first through-hole 151 in the first side cover portion 141 of the separation membrane sheet 120, which is connected to the folding portion 130 of the separation membrane sheet 120. For example, the cutter 230 can form a first through-hole 151 in the first side cover portion 141 of the separation membrane sheet 120 by moving the needle 231 vertically (e.g., in the Z direction) so that the needle 231 penetrates the first side cover portion 141 of the separation membrane sheet 120. The cutter 230 can form a plurality of first through-holes 151 arranged in a second horizontal direction (e.g., in the Y direction) in the first side cover portion 141 of the separation membrane sheet 120.

[0047] Referring to Figure 7, after the first punching process is completed, the secondary battery manufacturing apparatus performs a first winding process in which the cover portion 140 of the separation membrane sheet 120 is wound up such that the first side cover portion 141 of the separation membrane sheet 120 covers the first side surface 1151 of the cell structure 110 and the first bottom cover portion 142 of the separation membrane sheet 120 covers the bottom surface 1152 of the cell structure 110 (S130).

[0048] In step S130 described above, the first side cover portion 141 of the separation membrane sheet 120 faces the first side surface 1151 of the cell structure 110 and can contact the portion of the folding portion 130 that extends along the first side surface 1151 of the cell structure 110. The first bottom cover portion 142 of the separation membrane sheet 120 can contact the portion of the folding portion 130 that extends along the bottom surface 1152 of the cell structure 110.

[0049] In step S130 described above, winding the cover portion 140 of the separation membrane sheet 120 onto the cell structure 110 can be done by relative rotation between the cover portion 140 of the separation membrane sheet 120 and the cell structure 110. In an exemplary embodiment, the first winding step can be achieved by the holder 210, which holds the cell structure 110 and the folding portion 130, rotating with respect to a rotation axis parallel to a second horizontal direction (e.g., the Y direction) while the gripper 220 holds the cover portion 140 of the separation membrane sheet 120 in place. In an exemplary embodiment, the first winding step can be achieved by the gripper 220 moving so that the first side cover portion 141 and the first bottom cover portion 142 of the separation membrane sheet 120 surround the cell structure 110 while the holder 210 holds the cell structure 110 and the folding portion 130 in place.

[0050] Referring to Figures 8a and 8b, after the first winding process is completed, the secondary battery manufacturing apparatus performs a second punching process to form a second through-hole 152 in the second side cover portion 143 of the separation membrane sheet 120 (S140).

[0051] In step S140 described above, while the holder 210 supports the cell structure 110, the gripper 220 can support the cover portion 140 of the separation membrane sheet 120 such that the second side cover portion 143 of the separation membrane sheet 120 does not cover the second side surface 1153 of the cell structure 110. For example, the gripper 220 can support the cover portion 140 of the separation membrane sheet 120 such that the second side cover portion 143 of the separation membrane sheet 120 extends in a first horizontal direction (e.g., the X direction).

[0052] In step S140 described above, while the gripper 220 supports the cover portion 140 of the separation membrane sheet 120, the cutter 230 can form a second through-hole 152 in the second side cover portion 143 of the separation membrane sheet 120, which is connected to the first bottom cover portion 142 of the separation membrane sheet 120. For example, the cutter 230 can form a second through-hole 152 in the second side cover portion 143 of the separation membrane sheet 120 by moving the needle 231 vertically (e.g., in the Z direction) so that the needle 231 penetrates the second side cover portion 143 of the separation membrane sheet 120. The cutter 230 can form a plurality of second through-holes 152 arranged in a second horizontal direction (e.g., in the Y direction) in the second side cover portion 143 of the separation membrane sheet 120.

[0053] Referring to Figure 9, after the second punching process is completed, the secondary battery manufacturing apparatus performs a second winding process in which the cover portion 140 of the separation membrane sheet 120 is wound up such that the second side cover portion 143 of the separation membrane sheet 120 covers the second side surface 1153 of the cell structure 110 and the top cover portion 144 of the separation membrane sheet 120 covers the upper surface 1154 of the cell structure 110 (S150).

[0054] In step S150 described above, the second side cover portion 143 of the separation membrane sheet 120 faces the second side surface 1153 of the cell structure 110 and can contact the portion of the folding portion 130 that extends along the second side surface 1153 of the cell structure 110. The top cover portion 144 of the separation membrane sheet 120 can contact the portion of the folding portion 130 that extends along the upper surface 1154 of the cell structure 110.

[0055] In step S150 described above, winding the cover portion 140 of the separation membrane sheet 120 onto the cell structure 110 can be done by relative rotation between the cover portion 140 of the separation membrane sheet 120 and the cell structure 110. In an exemplary embodiment, the second winding step can be achieved by the holder 210, which holds the cell structure 110 and the folding portion 130, rotating with respect to a rotation axis parallel to a second horizontal direction (e.g., the Y direction) while the gripper 220 holds the cover portion 140 of the separation membrane sheet 120. In an exemplary embodiment, the second winding step can be achieved by the gripper 220 moving so that the second side cover portion 143 and the top cover portion 144 of the separation membrane sheet 120 surround the cell structure 110 while the holder 210 holds the cell structure 110 and the folding portion 130.

[0056] Referring to Figures 10a and 10b, after the second winding process is completed, the secondary battery manufacturing apparatus performs a third punching process to form a third through-hole 153 in the third side cover portion 145 of the separation membrane sheet 120 (S160).

[0057] In step S160 described above, while the holder 210 supports the cell structure 110, the gripper 220 can support the cover portion 140 of the separation membrane sheet 120 such that the third side cover portion 145 of the separation membrane sheet 120 does not cover the first side surface 1151 of the cell structure 110 and the first side cover portion 141 of the separation membrane sheet 120. For example, the gripper 220 can support the cover portion 140 of the separation membrane sheet 120 such that the third side cover portion 145 of the separation membrane sheet 120 extends in a first horizontal direction (e.g., the X direction).

[0058] In step S160 described above, while the gripper 220 supports the cover portion 140 of the separation membrane sheet 120, the cutter 230 can form a third through-hole 153 in the third side cover portion 145 of the separation membrane sheet 120, which is connected to the top cover portion 144 of the separation membrane sheet 120. For example, the cutter 230 can form a third through-hole 153 in the third side cover portion 145 of the separation membrane sheet 120 by moving the needle 231 vertically (e.g., in the Z direction) so that the needle 231 penetrates the third side cover portion 145 of the separation membrane sheet 120. The cutter 230 can form a plurality of third through-holes 153 arranged in a second horizontal direction (e.g., in the Y direction) in the third side cover portion 145 of the separation membrane sheet 120.

[0059] Referring to Figure 11, after the third punching process is completed, the secondary battery manufacturing apparatus performs a third winding process in which it winds up the cover portion 140 of the separation membrane sheet 120 such that the third side cover portion 145 of the separation membrane sheet 120 contacts the first side cover portion 141 of the separation membrane sheet 120 and the second bottom cover portion 146 of the separation membrane sheet 120 contacts the first bottom cover portion 142 of the separation membrane sheet 120 (S170).

[0060] In step S170 described above, the third side cover portion 145 of the separation membrane sheet 120 can cover the first side cover portion 141 of the separation membrane sheet 120. The third through hole 153 of the third side cover portion 145 can communicate with the first through hole 151 of the first side cover portion 141. The second bottom cover portion 146 of the separation membrane sheet 120 can contact the first bottom cover portion 142 of the separation membrane sheet 120.

[0061] In step S170 above, winding the cover portion 140 of the separation membrane sheet 120 onto the cell structure 110 can be done by relative rotation between the cover portion 140 of the separation membrane sheet 120 and the cell structure 110. In an exemplary embodiment, the third winding step can be achieved by the holder 210, which is holding the cell structure 110 and the folding portion 130, rotating with respect to a rotation axis parallel to a second horizontal direction (e.g., the Y direction) while the gripper 220 holds the cover portion 140 of the separation membrane sheet 120 in place. In an exemplary embodiment, the third winding step can be achieved by the gripper 220 moving so that the third side cover portion 145 and the second bottom cover portion 146 of the separation membrane sheet 120 surround the cell structure 110 while the holder 210 holds the cell structure 110 and the folding portion 130 in place.

[0062] Referring to Figure 1, after the third winding process is completed, the end of the cover portion 140 of the separation membrane sheet 120 is secured with tape 160 (S180). In step S180, the second bottom cover portion 146 is secured to the first bottom cover portion 142 by tape 160.

[0063] In the manufacturing method of the electrode assembly according to the comparative example, the entire cover portion of the separation membrane sheet is wound up so that the cover portion of the separation membrane sheet surrounds the cell structure, and then through holes for gas discharge are formed on both sides of the separation membrane sheet. In this case, during the process of cutting the separation membrane sheet with a cutter, there is a risk that the unit cells located adjacent to the cover portion of the separation membrane sheet may be damaged by the cutter.

[0064] According to an exemplary embodiment, after the punching process in which through holes are formed in the cover portion 140 of the separation membrane sheet 120 is completed, a winding process is performed in which the cover portion 140 of the separation membrane sheet 120 is wound up, thereby preventing damage to the unit cells 111 during the punching process.

[0065] (Third embodiment) Figure 12 is a cross-sectional view showing a manufacturing method for an electrode assembly 100 according to an exemplary embodiment.

[0066] Referring to Figure 12, in a secondary battery manufacturing apparatus configured to manufacture an electrode assembly 100, the cutter 230a may include a laser cutter configured to emit a laser beam 233. The cutter 230a can irradiate the cover portion 140 of the separation membrane sheet 120 with the laser beam 233 to form through holes in the cover portion 140 of the separation membrane sheet 120. According to an exemplary embodiment, after the punching step of forming through holes in the cover portion 140 of the separation membrane sheet 120 is completed, a winding step of winding the cover portion 140 of the separation membrane sheet 120 is performed, so that the unit cells 111 are not damaged by the laser beam 233 during the process of irradiating the separation membrane sheet 120 with the laser beam 233 to form through holes.

[0067] (Fourth Embodiment) Figure 13 is a cross-sectional view showing an electrode assembly 100A according to an exemplary embodiment. Hereinafter, the electrode assembly 100A shown in Figure 13 will be described, focusing on the differences from the electrode assembly 100 described with reference to Figures 1 to 3.

[0068] Referring to Figure 13, the electrode assembly 100A may include a cell structure 110A and a separation membrane sheet 120 having a folding portion 130 and a cover portion 140. The folding portion 130 of the separation membrane sheet 120 can be folded and extended in a zigzag pattern multiple times to define a plurality of vertically separated housing spaces 131, and the cell structure 110A can be housed within the plurality of housing spaces 131 of the folding portion 130. The cover portion 140 of the separation membrane sheet 120 can surround the cell structure 110A and the folding portion 130.

[0069] The cell structure 110A may include a first electrode 191, a second electrode 192, and an internal separation membrane 193. The internal separation membrane 193 may be interposed between the first electrode 191 and the second electrode 192. The first electrode 191 may extend by being folded in a zigzag pattern along the folding portion 130 of the separation membrane sheet 120. The first electrode 191 may be a single sheet. The second electrode 192 may extend by being folded in a zigzag pattern along the first electrode 191 or the folding portion 130 of the separation membrane sheet 120. The second electrode 192 may be a single sheet. The internal separation membrane 193 may be interposed between the first electrode 191 and the second electrode 192. The internal separation membrane 193 may extend by being folded in a zigzag pattern along the first electrode 191 or the folding portion 130 of the separation membrane sheet 120. The internal separation membrane 193 may be a single sheet.

[0070] The manufacturing method for the electrode assembly 100A may include a first step of preparing a first structure in which a separation membrane sheet 120, a first electrode 191, an internal separation membrane 193, and a second electrode 192 are sequentially stacked; a second step of forming a second structure in which the first structure is folded in a zigzag shape; and a third step of repeatedly punching and winding the cover portion 140 of the separation membrane sheet 120 to surround the cell structure 110A with the cover portion 140 of the separation membrane sheet 120. In the second step, by folding the first structure in a zigzag shape, the folding portion 130 of the separation membrane sheet 120 can be folded in a zigzag shape so as to have a plurality of accommodation spaces 131 for accommodating the cell structure 110A, and the folding portion 130 of the separation membrane sheet 120, the first electrode 191, the internal separation membrane 193, and the second electrode 192 can each be folded in a zigzag shape. The third step described above may include steps S120 to S180 in Figure 4.

[0071] (Fifth embodiment) Figure 14 is a cross-sectional view showing an electrode assembly 100B according to an exemplary embodiment. Hereinafter, the electrode assembly 100B shown in Figure 14 will be described, focusing on the differences from the electrode assembly 100A described with reference to Figure 13.

[0072] Referring to Figure 14, in the electrode assembly 100B, the folding portion 130 of the separation membrane sheet 120 can be folded and extended in a zigzag pattern multiple times to define multiple accommodation spaces 131 separated in the vertical direction, and the cell structure 110B can be accommodated within the multiple accommodation spaces 131 of the folding portion 130.

[0073] The cell structure 110B may include a first electrode 191, an internal separation membrane 193, and a plurality of second electrodes 192. The first electrode 191 and the internal separation membrane 193 are each single sheets and can be folded in a zigzag pattern along the folding portion 130 of the separation membrane sheet 120. Some of the plurality of second electrodes 192 can be housed in some of the multiple housing spaces 131 of the folding portion 130, and other parts of the plurality of second electrodes 192 can be housed in other parts of the multiple housing spaces 131 of the folding portion 130. The internal separation membrane 193 may be in contact with the top and bottom surfaces of some of the plurality of second electrodes 192, and the separation membrane sheet 120 may be in contact with the top and bottom surfaces of other parts of the plurality of second electrodes 192. Some of the multiple second electrodes 192 can be separated from the segments of the first electrode 191 positioned above and below them by an internal separation membrane 193, and other parts of the multiple second electrodes 192 can be separated from the other segments of the first electrode 191 positioned above and below them by a separation membrane sheet 120.

[0074] The manufacturing method for the electrode assembly 100B may include: a first step of preparing a third structure in which a separation membrane sheet 120, a first electrode 191, and an internal separation membrane 193 are sequentially stacked; a second step of forming a fourth structure by folding the third structure in a zigzag shape and arranging a plurality of second electrodes 192 in the space formed by the zigzag folding of the third structure; and a third step of repeatedly punching and winding the cover portion 140 of the separation membrane sheet 120 to surround the cell structure 110B with the cover portion 140 of the separation membrane sheet 120. In the second step, by folding the third structure in a zigzag shape, the folding portion 130 of the separation membrane sheet 120 can be folded in a zigzag shape to have a plurality of accommodation spaces 131, and the folding portion 130 of the separation membrane sheet 120, the first electrode 191, and the internal separation membrane 193 can each be folded in a zigzag shape. The third step described above may include steps S120 to S180 in Figure 4.

[0075] The present disclosure has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein represent only one embodiment of the present disclosure and do not represent the entire technical concept of the present disclosure. Therefore, there may be various equivalents and modifications that can be substituted for them at the time of filing.

Claims

1. A separation membrane sheet including a folding portion folded in a zigzag pattern to define multiple vertically separated containment spaces, and a cover portion extending from the folding portion, A cell structure comprising a first electrode and a second electrode, which is housed in the plurality of containment spaces of the separation membrane sheet, Includes, An electrode assembly wherein the cover portion of the separation membrane sheet includes a first side cover portion that covers the first side surface of the cell structure, and the first side cover portion includes a first through-hole that communicates with at least one of the plurality of housing spaces of the separation membrane sheet.

2. The electrode assembly according to claim 1, wherein the cover portion of the separation membrane sheet further includes a second side cover portion that covers a second side of the cell structure opposite to the first side of the cell structure, and the second side cover portion includes a second through-hole that communicates with at least one of the plurality of housing spaces of the separation membrane sheet.

3. The electrode assembly according to claim 2, wherein the cover portion of the separation membrane sheet further includes a third side cover portion that contacts the first side cover portion, and the third side cover portion includes a third through hole that communicates with the first through hole.

4. The cover portion of the separation membrane sheet is A first bottom cover portion extends between the first side cover portion and the second side cover portion and covers the bottom surface of the cell structure, A top cover portion extending between the second side cover portion and the third side cover portion and covering the upper surface of the cell structure, The electrode assembly according to claim 3, further comprising:

5. The electrode assembly according to claim 4, wherein the cover portion of the separation membrane sheet further includes a second bottom cover portion connected to the third side cover portion, and the second bottom cover portion is fixed to the first bottom cover portion.

6. The electrode assembly according to claim 1, wherein the separation membrane sheet is a single sheet.

7. The electrode assembly according to claim 1, wherein the cell structure includes a plurality of unit cells separated from each other by the folding portion of the separation membrane sheet, and each of the plurality of unit cells includes at least one of the first electrode and the second electrode.

8. The electrode assembly according to claim 1, wherein the cell structure is a single sheet extending in a zigzag pattern along the folding portion of the separation membrane sheet.

9. The electrode assembly according to claim 8, wherein the cell structure is a single sheet extending in a zigzag pattern along the first electrode.

10. A step of preparing a structure including a separation membrane sheet and a cell structure - the cell structure includes a first electrode and a second electrode, and the separation membrane sheet includes a folding portion that defines a plurality of housing spaces for housing the cell structure, and a cover portion connected to the folding portion - A first punching step in which a first through hole is formed in the first side cover portion of the cover portion of the separation membrane sheet, A first winding step involves winding the cover portion of the separation membrane sheet so that the first side cover portion of the separation membrane sheet faces the first side surface of the cell structure, A method for manufacturing an electrode assembly, including the following:

11. The method for manufacturing an electrode assembly according to claim 10, wherein the first winding step further includes winding the cover portion of the separation membrane sheet such that the first bottom cover portion of the cover portion of the separation membrane sheet, which is connected to the first side cover portion of the separation membrane sheet, faces the bottom surface of the cell structure.

12. A second punching step is performed to form a second through-hole in the second side cover portion of the cover portion of the separation membrane sheet, A second winding step involves winding the cover portion of the separation membrane sheet so that the second side cover portion of the separation membrane sheet faces the second side surface of the cell structure, A method for manufacturing an electrode assembly according to claim 10, further comprising:

13. The method for manufacturing an electrode assembly according to claim 12, wherein the second winding step further includes winding the cover portion of the separation membrane sheet such that the top cover portion of the cover portion of the separation membrane sheet, which is connected to the second side cover portion of the separation membrane sheet, faces the upper surface of the cell structure.

14. A third punching step is performed to form a third through-hole in the third side cover portion of the cover portion of the separation membrane sheet, A third winding step in which the cover portion of the separation membrane sheet is wound up so that the third side cover portion of the separation membrane sheet contacts the first side cover portion of the cover portion of the separation membrane sheet, It further includes, The method for manufacturing an electrode assembly according to claim 12, wherein the first through-hole provided in the first side cover portion of the separation membrane sheet is aligned with the third through-hole provided in the third side cover portion of the separation membrane sheet.

15. The first winding step further includes winding the cover portion of the separation membrane sheet so that the first bottom cover portion of the cover portion of the separation membrane sheet, which is connected to the first side cover portion of the separation membrane sheet, faces the bottom surface of the cell structure. The method for manufacturing an electrode assembly according to claim 14, wherein the third winding step further includes winding the cover portion of the separation membrane sheet such that the second bottom cover portion of the cover portion of the separation membrane sheet, which is connected to the third side cover portion of the separation membrane sheet, contacts the first bottom cover portion of the separation membrane sheet.

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