Separator laminate and electrode assembly containing the same, and method for manufacturing an electrode assembly.

Abstract

This invention relates to a separator laminate, an electrode assembly containing the same, and a method for manufacturing the electrode assembly. [Solution] An electrode assembly according to one embodiment of the present invention may include a separator stack formed by folding a sealing portion in the center of a plurality of separators stacked on top of each other, and a plurality of electrodes inserted between the plurality of separators, wherein the sealing portion may be located on one side of the plurality of electrodes.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0130273 filed on September 30, 2021, and all the contents disclosed in the Korean patent application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a separator laminate, an electrode assembly including the same, and a method of manufacturing the electrode assembly.

Background Art

[0003] Generally, a secondary battery means a battery that can be charged and discharged, unlike a primary battery that cannot be charged, and is widely used in electronic devices such as mobile phones, notebook computers, camcorders, or electric vehicles. In particular, lithium secondary batteries have a larger capacity than nickel-cadmium batteries or nickel-metal hydride batteries and a high energy density per unit weight, so their utilization is rapidly increasing.

[0004] Lithium secondary batteries may be classified according to the structure of the electrode assembly having a positive electrode / separator / negative electrode structure. Typically, a jelly roll electrode assembly in which a long sheet-shaped electrode is wound with a separator interposed therebetween, a stack-type electrode assembly in which a number of electrodes cut out in a predetermined size unit are sequentially stacked with a separator interposed therebetween, a bi-cell or full-cell in which a predetermined unit electrode is stacked with a separator interposed therebetween, and a stack / folding-type electrode assembly having a structure in which the bi-cell or full-cell is wound, etc. may be mentioned.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide an electrode assembly in which the alignment of the electrodes is easy and the stability is improved, and a separator laminate included therein.

[0006] Another problem that the present invention aims to solve is to provide a method for manufacturing an electrode assembly using a novel electrode stacking method. [Means for solving the problem]

[0007] A separator laminate according to one embodiment of the present invention may include a plurality of separators stacked on top of each other, each having a pair of first edges extending in a first direction and a pair of second edges extending in a second direction perpendicular to the first direction, and a sealing portion formed by sealing the central portions of the plurality of separators with respect to the first direction with respect to each other and extending in the second direction.

[0008] The width of the sealing portion in the first direction can be narrowed upwards with respect to the stacking direction of the plurality of separators.

[0009] The pair of second edges of the plurality of separators can be positioned inward toward the upward direction with respect to the stacking direction of the plurality of separators.

[0010] The sealing portion may have a symmetrical shape with respect to the first direction.

[0011] The aforementioned plurality of separators can be folded around the sealing portion.

[0012] An electrode assembly according to one embodiment of the present invention may include a separator stack in which a sealing portion is formed in the center of a plurality of separators stacked on top of each other, and which is folded around the sealing portion, and a plurality of electrodes inserted between the plurality of separators. The sealing portion may be located on one side of the plurality of electrodes.

[0013] At least some of the aforementioned plurality of electrodes can be in contact with or adjacent to the sealing portion.

[0014] The thickness of the sealing portion can increase toward the center of the separator laminate with respect to the stacking direction.

[0015] The sealing portion may have a shape that is symmetrical with respect to the stacking direction of the separator laminate.

[0016] The outer surface of the sealing portion can be flat or be bent or folded in a convex shape toward the outside of the separator laminate.

[0017] The separator laminate has a sub-sealing portion located on the other side of the plurality of electrodes, where the plurality of separators are sealed to each other, and the sub-sealing portion may have a shape asymmetric to the sealing portion.

[0018] A separator laminate according to another embodiment of the present invention may include a base separator having a pair of first edges extending in a first direction and a pair of second edges extending in a second direction perpendicular to the first direction, a substrate portion provided in the central part of the base separator with respect to the first direction and formed to extend in the second direction, and a plurality of main separators having fixed edges connected to the substrate portion.

[0019] With respect to the first direction, some of the multiple main separators can spread to one side, and other parts can spread to the other side.

[0020] The base separator can be folded around the base material portion such that the multiple main separators come together.

[0021] In the aforementioned plurality of main separators, the non-fixed edges located on the opposite side of the fixed edges can be positioned inward toward the upward direction with respect to the stacking direction.

[0022] An electrode assembly according to another embodiment of the present invention can include a separator laminate in which one edge of a plurality of main separators is fixed to a base material portion provided at the center of a base separator and is folded around the base material portion, and a plurality of electrodes inserted between the base separator and the plurality of main separators. The base material portion can be located on one side of the plurality of electrodes.

[0023] The plurality of electrodes can contact or be adjacent to the base material portion.

[0024] The thickness of the base material portion can be constant with respect to the stacking direction of the plurality of main separators.

[0025] The base material portion can be flat or bent or folded convexly toward the outside of the separator laminate.

[0026] In the separator laminate, a sub-sealing portion is formed on the other side of the plurality of electrodes, where the base separator and the plurality of main separators are fused to each other, and the sub-sealing portion can have a shape asymmetric with respect to the base material portion.

[0027] A method for manufacturing an electrode assembly according to an embodiment of the present invention can include the steps of preparing a separator laminate in which the central portions of a plurality of separators stacked on each other are sealed to each other to form a sealing portion, folding the separator laminate around the sealing portion, and inserting a plurality of electrodes between the plurality of separators.

[0028] The step of preparing the separator laminate can be repeatedly performed by a process of stacking another separator on top of one separator and a process of fusing the central portions of the one separator and the other separator to each other to form a sealing portion. The width of the sealing portion can become narrower toward the upper side with respect to the stacking direction of the separator laminate.

[0029] The method may further include a step of sealing the plurality of separators to each other on the opposite side of the sealing portion to form a sub-sealing portion.

[0030] A method for manufacturing an electrode assembly according to another embodiment of the present invention may include a step of preparing a separator laminate in which one edge of a plurality of main separators is fixed to a base material portion provided at a central portion of a base separator, a step of folding the separator laminate around the base material portion, and a step of inserting a plurality of electrodes between the base separator and the plurality of main separators.

[0031] The method may further include a step of sealing edges located on the opposite side of the base material portion with respect to the base separator and the plurality of main separators to each other.

Advantages of the Invention

[0032] According to a preferred embodiment of the present invention, compared with conventional methods for manufacturing electrode assemblies in various ways, there are advantages in that the manufacturing process can be simplified and manufacturing equipment can be simplified.

[0033] Also, since a separator laminate without electrodes is manufactured first, accurate alignment between the plurality of separators is possible, and since a plurality of electrodes are inserted into the separator laminate simultaneously or sequentially, there is an advantage in that accurate alignment between the plurality of electrodes is possible. Thereby, the quality and energy density of the electrode assembly can be improved.

[0034] Also, since the sealing stability of the sealing portion or the base material portion provided in the separator laminate is maintained high, it is possible to prevent the plurality of electrodes from detaching from the separator laminate. Thereby, it is possible to prevent a short circuit from occurring between the plurality of electrodes and improve the stability of the electrode assembly.

[0035] Furthermore, since the thickness of the sealing portion or base material portion provided in the separator laminate is formed to be relatively thinner than the thickness of the conventional separator sealing portion, multiple electrodes can be efficiently heat-dissipated.

[0036] Furthermore, the present invention may include effects that are easily predictable to those skilled in the art from the configuration of preferred embodiments. [Brief explanation of the drawing]

[0037] [Figure 1] This is a side view of a separator stack according to one embodiment of the present invention. [Figure 2] Figure 1 is a plan view of the separator laminate shown. [Figure 3] This is a side view illustrating how multiple electrodes are inserted into a separator stack according to one embodiment of the present invention. [Figure 4] This is a magnified view of the "A" section shown in Figure 3. [Figure 5] This is a side view of an electrode assembly according to one embodiment of the present invention. [Figure 6] This is a flowchart of a method for manufacturing an electrode assembly according to one embodiment of the present invention. [Figure 7] This is a side view of a separator laminate according to another embodiment of the present invention. [Figure 8] This is a side view illustrating how multiple electrodes are inserted into a separator laminate according to another embodiment of the present invention. [Figure 9] This is a magnified view of the "B" section shown in Figure 8. [Figure 10] This is a side view of an electrode assembly according to another embodiment of the present invention. [Figure 11] This is a flowchart of a method for manufacturing an electrode assembly according to another embodiment of the present invention. [Figure 12] This is an exploded perspective view of a secondary battery including an electrode assembly according to one embodiment of the present invention. [Figure 13] Figure 12 is a schematic diagram of a battery module including a secondary battery. [Modes for carrying out the invention]

[0038] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention can be realized in a variety of different forms and is not limited or restricted by the following embodiments.

[0039] To clearly illustrate the present invention, detailed descriptions of related known technologies that are irrelevant to the description or that could obscure the gist of the invention are omitted. In this specification, when assigning reference numerals to components in the drawings, the same or similar reference numerals are used for components that are the same or similar throughout the specification.

[0040] Furthermore, the terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather should be interpreted in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors may appropriately define the concepts of terms in order to best explain their invention.

[0041] Figure 1 is a side view of a separator laminate according to one embodiment of the present invention, and Figure 2 is a plan view of the separator laminate shown in Figure 1.

[0042] A separator laminate 100 according to one embodiment of the present invention may include a plurality of separators 110 stacked on top of each other, and a sealing portion 120 formed by sealing the central portions of the plurality of separators 110 together.

[0043] Each separator 110 may include a pair of first edges 110a extending in a first direction and a pair of second edges 110b extending in a second direction perpendicular to the first direction. Thus, the pair of second edges 110b of each separator 110 can form both ends of the separator 110 with respect to the first direction.

[0044] The first direction can be parallel to either the length direction or the width direction of the separator 110, and the second direction can be parallel to the other of the length direction or the width direction of the separator 110.

[0045] The sealing portion 120 can be formed by sealing the central portions of a plurality of separators 110 in the first direction to each other. The sealing portion 120 can be formed to be elongated in the second direction.

[0046] The width of the sealing portion 120 in the first direction can be narrowed upwards with respect to the stacking direction of the multiple separators 110. That is, the lower width w1 of the sealing portion 120 can be wider than the upper width w2.

[0047] Therefore, the thickness of the sealing portion 120 in the stacking direction of the multiple separators 110 can increase toward the center in the first direction.

[0048] Furthermore, the sealing portion 120 can have a symmetrical shape with respect to the first direction. Both ends of the sealing portion 120 with respect to the first direction can be positioned inward toward the upward direction with respect to the stacking direction of the plurality of separators 110.

[0049] For this reason, a sealing portion 120 can be formed each time a separator 110 is sealed, and the width of the sealing portion 120 can be made to gradually narrow as the separators 110 are stacked.

[0050] More specifically, when the second separator 110 is stacked on top of the first separator 110, the central portions of the first separator 110 and the second separator 110 are sealed to each other, forming a sealing portion 120 having a first width. Next, when the third separator 110 is stacked on top of the second separator 110, the central portions of the second separator 110 and the third separator 110 are sealed to each other, forming a second sealing portion 120 having a second width narrower than the first width. Here, the first to third separators are not specific separators, but arbitrary names used to describe the stacking order of the separators.

[0051] By repeating this process and stacking and sealing multiple separators 110, a separator stack 100 can be formed in which the width of the sealing portion 120 narrows towards the top.

[0052] Furthermore, the separator laminate 100, or more specifically, the multiple separators 110, can be folded around the sealing portion 120 (see Figure 3). Therefore, the length of the separator laminate 100 in the first direction can be reduced by approximately half, and the height in the stacking direction can be increased by approximately twofold.

[0053] More specifically, the separator laminate 100 can be folded in a direction such that a portion of the last-to-last-laid separator 110 and other portions of the multiple separators 110 face each other. Therefore, the portion of the last separator 110 and other portions of the folded separator laminate 100 can be located in the center of the stacking direction and face each other. Also, a portion of the first-to-last-laid separator 110 and other portions of the multiple separators 110 can form the outermost edges of the folded separator laminate 100.

[0054] In other words, the separator laminate 100 according to this embodiment can have a structure similar to a bound book, where the first separator 110 corresponds to the cover of the book, and the other separators 110 correspond to each page of the book.

[0055] The folded separator laminate 100 will be described in more detail below.

[0056] On the other hand, the pair of second edges 110b of the multiple separators 110 can be positioned inward toward the upward direction with respect to the stacking direction of the multiple separators 110. That is, the length between the pair of second edges 110b of the multiple separators 110 can be shortened toward the upward direction with respect to the stacking direction. As a result, when the separator stack 100 is folded around the sealing portion 120 (see Figure 3), the lengths from the sealing portion 120 to the multiple second edges 110b of the multiple separators 110 can be the same or similar to each other.

[0057] However, the method is not limited to this, and it is also possible to stack multiple separators 110 having a predetermined length. In this case, with the separator stack 100 folded around the sealing portion 120, a further step can be taken to cut a portion of the separator stack 100 so that the lengths from the sealing portion 120 to multiple second edges 110b are the same or similar to each other.

[0058] Figure 3 is a side view illustrating the insertion of multiple electrodes into a separator stack according to one embodiment of the present invention, Figure 4 is an enlarged view of the "A" portion shown in Figure 3, and Figure 5 is a side view of an electrode assembly according to one embodiment of the present invention.

[0059] An electrode assembly 10 according to one embodiment of the present invention may include a separator laminate 100 folded around a sealing portion 120, and a plurality of electrodes 200 inserted between a plurality of separators 110.

[0060] The following description of the separator laminate 100 will be based on its folded state.

[0061] A sealing portion 120 is located on one side of the separator laminate 100, and the second edges 110b of multiple separators 100 can be located on the other side.

[0062] The shape of the sealing portion 120 can vary depending on the degree to which the separator laminate 100 folds. For example, the outer surface 120a of the sealing portion 120 can be formed flat, as shown in Figure 4. As another example, the outer surface 120a of the sealing portion 120 can be bent or folded convexly outward from the separator laminate 100.

[0063] The outer surface 120a of the sealing portion 120 can form part of the periphery of the separator laminate 100.

[0064] The thickness t of the sealing portion 120 can increase toward the center with respect to the stacking direction of the separator laminate 100. Therefore, the sealing portion 120 can have its maximum thickness tm at the center of the separator laminate 100 in the stacking direction.

[0065] Here, the thickness t of the sealing portion 120 can mean the distance from the point where each separator 110 and the sealing portion 120 are connected to the outer surface 120a of the sealing portion 120, with respect to the direction perpendicular to the outer surface 120a of the sealing portion 120. For example, if the outer surface 120a of the sealing portion 120 is formed flat, the thickness t of the sealing portion 120 can be parallel to the first direction.

[0066] The sealing portion 120 can have a shape that is symmetrical with respect to the stacking direction of the separator laminate 100.

[0067] Furthermore, the sealing portion 120 can be located on one side of the plurality of electrodes 200. At least some of the plurality of electrodes 200 can be in contact with or adjacent to the sealing portion 120. The sealing portion 120 can prevent the plurality of electrodes 200 from detaching from the separator laminate 100.

[0068] Multiple electrodes 200 can be inserted between multiple separators 110 contained in the separator laminate 100. Multiple electrodes 200 can include multiple positive electrodes and multiple negative electrodes positioned alternately on either side of the separator 110.

[0069] Each electrode 200 can be formed by coating a plate-shaped current collector with an electrode active material. Furthermore, an electrode tab 210 (see Figure 12) can be connected to each electrode 200, and the electrode tab 210 can be a plain portion of the current collector where no electrode active material is coated.

[0070] Multiple electrode tabs 210 can protrude from one or both sides of the electrode assembly 10. More specifically, the multiple electrode tabs 210 may include a positive electrode tab connected to the positive electrode and a negative electrode tab connected to the negative electrode, and the positive electrode tab and the negative electrode tab can protrude parallel to each other or in opposite directions.

[0071] Multiple electrode tabs 210 can protrude in a direction that does not interfere with the sealing portion 120 and the sub-sealing portion 130 of the separator laminate 100, which will be described later.

[0072] On the other hand, a sub-sealing portion 130 can be formed in the separator laminate 100.

[0073] The sub-sealing portion 130 can be located on the opposite side of the sealing portion 120, with the multiple electrodes 200 in between. That is, the sealing portion 120 can be located on one side of the multiple electrodes 200, and the sub-sealing portion 130 can be located on the other side of the multiple electrodes 200.

[0074] The sub-sealing portion 130 can be formed by sealing a plurality of separators 110 together. More specifically, the sub-sealing portion 130 can be formed by sealing the second edges 110b of a plurality of separators 110 together.

[0075] More specifically, the sub-sealing portion 130 can be heat-sealed by having the second edges 110b of multiple separators 110 converge towards the center using another sealing tool (not shown), or by folding them in random directions. Therefore, when the sub-sealing portion 130 is formed, it will always have an asymmetrical shape to the sealing portion 120.

[0076] However, it goes without saying that the sub-sealing portion 130 does not necessarily have to be formed on the separator laminate 100.

[0077] Figure 6 is a flowchart showing a method for manufacturing an electrode assembly according to one embodiment of the present invention.

[0078] A method for manufacturing an electrode assembly 10 according to one embodiment of the present invention may include the steps of: preparing a separator laminate 100 in which the central portions of a plurality of separators 110 stacked on top of each other are fused together to form a sealing portion 120 (S10); folding the separator laminate 100 around the sealing portion 120 (S20); and inserting a plurality of electrodes 200 between the plurality of separators 110 (S30).

[0079] In step (S10) of preparing the separator laminate 100, the sealing portion 120 can be formed in the central part of the plurality of separators 110 with respect to the first direction, and the sealing portion 120 can be formed to be elongated in a second direction perpendicular to the first direction.

[0080] The step (S10) of preparing the separator laminate 100 can involve repeatedly stacking one separator 110 on top of another separator 110, and fusing the central parts of one separator 110 and another separator 110 together to form a sealing portion 120. The width of the sealing portion 120 can be formed to narrow towards the top with respect to the stacking direction of the separator laminate 100.

[0081] Therefore, the sealing portion 120 formed in the center of the separator laminate 100 can have a shape in which the width narrows towards the upward direction with respect to the stacking direction of the separator laminate 100.

[0082] In step (S20) of folding the separator laminate 100, the separator laminate 100 can be folded around the sealing portion 120 which is formed to be elongated in the second direction. More specifically, the separator laminate 100 can be folded in a direction in which a portion of the last separator 110, which is the last to be laminated among the plurality of separators 110, faces the other portions.

[0083] Therefore, when the separator laminate 100 is folded, the sealing portion 120 can be located on one side of the separator laminate 100, and the thickness t of the sealing portion 120 (see Figure 4) can increase toward the center with respect to the stacking direction of the separator laminate 100.

[0084] Furthermore, the shape of the sealing portion 120 may change depending on the degree of folding of the separator laminate 100.

[0085] For example, when the separator laminate 100 is folded, the sealing portion 120 itself does not fold, and the shape of the sealing portion 120 can be maintained. In this case, the outer surface 120a of the sealing portion 120 can be flat.

[0086] As another example, when the separator laminate 100 is folded, the sealing portion 120 can bend together with the multiple separators 110. In this case, the outer surface 120a of the sealing portion 120 can be bent or folded in a convex shape toward the outside of the separator laminate 100.

[0087] In step (S30) of inserting multiple electrodes 200, the multiple electrodes 200 can be inserted into the separator laminate 100 simultaneously or sequentially.

[0088] For example, multiple guide slits (not shown) can be inserted between multiple separators 110, and each electrode 200 can be inserted into the separator laminate 100 through the guide slits. Next, the guide slits can be removed.

[0089] As a result, the sealing portion 120 of the separator laminate 100 can be located on one side of the plurality of electrodes 200, and can be in contact with or adjacent to at least a portion of the plurality of electrodes 200.

[0090] Furthermore, the electrode tabs 210 (see Figure 12) provided on multiple electrodes 200 can protrude to the outside of the separator laminate 100. More specifically, the electrode tabs 210 can protrude in a direction that does not interfere with the sealing portion 120.

[0091] On the other hand, although not shown in Figure 6, the method for manufacturing the electrode assembly 10 according to this embodiment may further include the step of sealing a plurality of separators 110 together on the opposite side of the sealing portion 120 to form a sub-sealing portion 130.

[0092] More specifically, the second edges 110b of multiple separators 110 can be sealed together by another sealing tool (not shown) to form a sub-sealing portion 130. The sealing portion 120 and the sub-sealing portion 130 can be located on opposite sides of multiple electrodes 200 and can have asymmetrical shapes.

[0093] In this case, the electrode tabs 210 (see Figure 12) provided on the multiple electrodes 200 can protrude in a direction that does not interfere with the sealing portion 120 and the sub-sealing portion 130.

[0094] Compared to conventional methods for manufacturing electrode assemblies, the manufacturing method for the electrode assembly 10 according to this embodiment is relatively simple, offering the advantages of a simplified manufacturing process and simplified manufacturing equipment.

[0095] Furthermore, since the separator laminate 100 without the electrodes 200 is manufactured first, there is the advantage of being able to accurately align multiple separators 110. Also, since multiple electrodes 200 are inserted into the separator laminate 100 simultaneously or sequentially, there is the advantage of being able to accurately align multiple electrodes 200. This makes it possible to improve the quality and energy density of the electrode assembly 10.

[0096] Furthermore, compared to conventional designs, the sealing stability of the sealing portion 120 can be improved, and the sealing portion 120 can prevent the multiple electrodes 200 from detaching from the separator laminate 100. This prevents short circuits from occurring between the multiple electrodes 200 and improves the stability of the electrode assembly 10.

[0097] Figure 7 is a side view of a separator laminate according to another embodiment of the present invention.

[0098] The separator laminate 100' according to this embodiment may include a base separator 111, a substrate portion 140 positioned in the center of the base separator 111, and a plurality of main separators 112 connected to the substrate portion 140.

[0099] The base separator 111 may include a pair of first edges extending in a first direction and a pair of second edges 111b extending in a second direction perpendicular to the first direction. Therefore, the pair of second edges 110b of the base separator 111 can form both ends of the separator 110 in the first direction.

[0100] The first direction can be parallel to either the length direction or the width direction of the base separator 111, and the second direction can be parallel to the other of the length direction or the width direction of the base separator 111.

[0101] The base separator 111 may be a single separator or may include a pair of separators connected to the base material portion 140 (described later) and separated from each other. In the following explanation, the case in which the base separator 111 is a single separator will be used as an example.

[0102] The base material portion 140 can be provided in the central part of the base separator 111 in the first direction. More specifically, the base material portion 140 can be provided in the central part of the upper surface of the base separator 111 in the first direction. The base material portion 140 can also be formed to be elongated in the second direction. It is preferable that the width and thickness of the base material portion 140 be constant.

[0103] The base material 140 can be configured to allow the edge 112a of the main separator 112 (described later) to be fixed to it, and its material is not limited. For example, the base material 140 may contain an adhesive or a heat-sealable polymer resin.

[0104] Each of the multiple main separators 112 may have one edge 112a connected to the base material 140 and another edge 112b located on the opposite side of the one edge 112a. The one edge 112a and the other edge 112b may extend parallel to each other in the second direction.

[0105] In the following explanation, for convenience, one of the edges 112a will be referred to as a fixed edge, and the other edge 112b will be referred to as an unfixed edge.

[0106] The fixed edge 112a of each main separator 112 can be connected perpendicularly to the base material 140.

[0107] Furthermore, some of the multiple main separators 112 can be deployed to one side with respect to the first direction, while other parts can be deployed to the other side.

[0108] Furthermore, the separator laminate 100' can be folded around the base material portion 140. More specifically, the base separator 111 can be folded around the base material portion 140 such that multiple main separators 112 come together (see Figure 8). Thus, the multiple main separators 112 can come together so as to face each other with respect to the lamination direction, and parts of the base separator 111 and other parts can form the outermost edges of the folded separator laminate 100'.

[0109] In other words, the separator laminate 100' according to this embodiment can have a structure similar to a bound book, with the base separator 111 corresponding to the book's cover and the main separator 112 corresponding to each page of the book.

[0110] The folded separator laminate 100' will be described in more detail later.

[0111] On the other hand, the non-fixed edges 112b of multiple main separators 112 can be located inside the second edge 111b of the base separator 111.

[0112] Furthermore, the non-fixed edges 112b of the multiple main separators 112 can be positioned inward toward the upward direction with respect to the stacking direction of the multiple main separators 112. In other words, the length from the fixed edge 112a to the non-fixed edge 112b of the multiple main separators 112 can be shortened toward the upward direction with respect to the stacking direction.

[0113] As a result, when the separator laminate 100' is folded around the base material portion 140 (see Figure 8), the lengths from the base material portion 140 to the multiple non-fixed edges 112b can be the same or similar for multiple main separators 112.

[0114] However, the method is not limited to this, and it is also possible to use multiple main separators 112 having a predetermined length. In this case, with the separator laminate 100' folded around the base material 140, a further step can be taken to cut a portion of the separator laminate 100' so that the lengths from the base material 140 to multiple non-fixed edges 112b are the same or similar to each other.

[0115] Figure 8 is a side view illustrating how multiple electrodes are inserted into a separator laminate according to another embodiment of the present invention, Figure 9 is an enlarged view of the "B" portion shown in Figure 8, and Figure 10 is a side view of an electrode assembly according to another embodiment of the present invention.

[0116] An electrode assembly 10' according to one embodiment of the present invention may include a separator laminate 100' folded around a base material portion 140, and a plurality of electrodes 200 inserted between a plurality of separators 111, 112.

[0117] The separator laminate 100' will be described below based on its folded state.

[0118] On one side of the separator laminate 100', the base material portion 120 is located, and on the other side, the unfixed edges 112b of multiple main separators 112 and the second edge 111b of the base separator 111 can be located.

[0119] If the base separator 111 is a single separator, a portion of the base separator 111 can cover the substrate portion 140 from the outside. However, it is not limited to this, and if the base separator 111 includes a pair of separators connected to the substrate portion 140 and spaced apart from each other, the substrate portion 140 can form part of the periphery of the separator laminate 100'.

[0120] The shape of the base material 140 can vary depending on the degree to which the separator laminate 100' folds. For example, the base material 140 can be formed flat, as shown in Figure 9. As another example, the base material 140 can be bent or folded in a convex shape toward the outside of the separator laminate 100'.

[0121] The thickness of the base material 140 can be constant with respect to the stacking direction of the multiple main separators 112.

[0122] Furthermore, the base material 140 can be located on one side of the multiple electrodes 200. The multiple electrodes 200 can be in contact with or adjacent to the base material 140. The base material 140 can prevent the multiple electrodes 200 from detaching from the separator laminate 100'.

[0123] Multiple electrodes 200 can be inserted between the base separator 111 and multiple main separators 112 contained in the separator laminate 100'. More specifically, the two outermost electrodes 200 of the multiple electrodes 200 can be inserted between the base separator 111 and the main separator 112, and the remaining electrodes 200 can be inserted between the multiple main separators 112.

[0124] The multiple electrodes 200 may include multiple positive electrodes and multiple negative electrodes positioned alternately on either side of the separators 111 and 112.

[0125] Each electrode 200 can be formed by coating a plate-shaped current collector with an electrode active material. Furthermore, an electrode tab 210 (see Figure 12) can be connected to each electrode 200, and the electrode tab 210 can be a plain portion of the current collector where no electrode active material is coated.

[0126] Multiple electrode tabs 210 can protrude from one or both sides of the electrode assembly 10'. More specifically, the multiple electrode tabs 210 may include a positive electrode tab connected to the positive electrode and a negative electrode tab connected to the negative electrode, and the positive electrode tab and the negative electrode tab can protrude parallel to each other or in opposite directions.

[0127] Multiple electrode tabs 210 can protrude in a direction that does not interfere with the base material portion 140 and the sub-sealing portion 150 of the separator laminate 100', which will be described later.

[0128] On the other hand, a sub-sealing portion 150 can be formed in the separator laminate 100'.

[0129] The sub-sealing portion 150 can be located on the opposite side of the base material portion 140, with the multiple electrodes 200 in between. That is, the base material portion 140 can be located on one side of the multiple electrodes 200, and the sub-sealing portion 150 can be located on the other side of the multiple electrodes 200.

[0130] The sub-sealing section 150 can be formed by sealing multiple separators 111 and 112 together. More specifically, the sub-sealing section 130 can be formed by sealing the unfixed edges 112b of multiple main separators 112 together with the second edge 111b of the base separator 111 together.

[0131] More specifically, the sub-sealing portion 150 can be heat-sealed by having the unfixed edges 112b of the multiple main separators 112 and the second edge 111b of the base separator 111 converge in the center using another sealing tool (not shown), or by folding them in random directions and then heat-sealing them. Therefore, when the sub-sealing portion 150 is formed, it will always have an asymmetrical shape with respect to the base material portion 140.

[0132] However, it goes without saying that the sub-sealing portion 150 does not necessarily have to be formed on the separator laminate 100'.

[0133] Figure 11 is a flowchart of a method for manufacturing an electrode assembly according to another embodiment of the present invention.

[0134] A method for manufacturing an electrode assembly 10' according to one embodiment of the present invention may include the steps of: preparing a separator laminate 100' in which one edge 112a of a plurality of main separators 112 is fixed to a base material portion 140 provided in the center of a base separator 111 (S10'); folding the separator laminate 100' around the base material portion 140 (S20'); and inserting a plurality of electrodes 200 between the base separator 111 and the plurality of main separators 112 (S30').

[0135] In the step (S10') of preparing the separator laminate 100', the base material portion 140 can be provided in the central part of the base separator 111 with respect to the first direction, and can be formed to be elongated in a second direction perpendicular to the first direction. The base material portion 140 can also have a predetermined width and thickness.

[0136] For example, the adhesive can be applied to or coated on the central part of the upper surface of the base separator 111 to form the base material portion 140.

[0137] As another example, an adhesive member or polymer resin member provided separately from the base separator 111 can be attached to or joined to the central part of the upper surface of the base separator 111 to form the base material portion 140.

[0138] As another example, a pair of separators spaced apart in a first direction can be connected to a separately provided adhesive member or polymer resin member. In this case, the pair of separators can form a base separator 111, and the adhesive member or polymer resin member can form a base material portion 140.

[0139] In step (S20) of folding the separator laminate 100', the separator laminate 100' can be folded around the base material portion 140 which is formed to be elongated in the second direction. More specifically, the separator laminate 100' can be folded in a direction in which a plurality of main separators 112 come together facing each other.

[0140] Therefore, when the separator laminate 100 is folded, the base material portion 140 can be located on one side of the separator laminate 100', and the thickness of the base material portion 140 can be constant with respect to the stacking direction of the separator laminate 100'.

[0141] Furthermore, the shape of the base material portion 140 may change depending on the degree of folding of the separator laminate 100'.

[0142] For example, when the separator laminate 100' is folded, the base material portion 140 itself does not fold, and the shape of the base material portion 140 can be maintained. In this case, the base material portion 140 can be flat.

[0143] As another example, when the separator laminate 100' is folded, the base material 140 can deform together with the base separator 111. In this case, the base material 140 can be bent or folded in a convex shape toward the outside of the separator laminate 100'.

[0144] In the step of inserting multiple electrodes 200 (S30'), the multiple electrodes 200 can be inserted into the separator laminate 100' simultaneously or sequentially.

[0145] For example, multiple guide slits (not shown) can be inserted between multiple separators 111 and 112, and each electrode 200 can be inserted into the separator laminate 100' through the guide slits. Thereafter, the guide slits can be removed.

[0146] As a result, the base material portion 140 of the separator laminate 100' can be located on one side of the multiple electrodes 200, and can be in contact with or adjacent to the multiple electrodes 200.

[0147] Furthermore, the electrode tabs 210 (see Figure 12) provided on multiple electrodes 200 can protrude to the outside of the separator laminate 100'. More specifically, the electrode tabs 210 can protrude in a direction that does not interfere with the base material portion 140.

[0148] On the other hand, although not shown in Figure 11, the method for manufacturing the electrode assembly 10' according to this embodiment may further include the step of sealing a plurality of separators 111 and 112 with each other on the opposite side of the base material portion 140 to form a sub-sealing portion 150.

[0149] More specifically, the second edge 111b of the base separator 111 and the unfixed edges 112b of the multiple main separators 112 can be sealed to each other by another sealing tool (not shown) to form a sub-sealing portion 150. The base material portion 140 and the sub-sealing portion 150 can be located on opposite sides of the multiple electrodes 200 and can have asymmetrical shapes.

[0150] In this case, the electrode tabs 210 (see Figure 12) provided on the multiple electrodes 200 can protrude in a direction that does not interfere with the base material portion 140 and the sub-sealing portion 150.

[0151] The manufacturing method of the electrode assembly 10' according to this embodiment has the advantage of enabling precise alignment between multiple separators 111 and 112 because the separator laminate 100' without electrodes 200 is manufactured first. Furthermore, since multiple electrodes 200 are inserted into the separator laminate 100' simultaneously or sequentially, precise alignment between multiple electrodes 200 is possible. As a result, the quality and energy density of the electrode assembly 10' can be improved.

[0152] Furthermore, the sealing stability of the base material 140 can be improved, and the base material 140 can prevent the multiple electrodes 200 from detaching from the separator laminate 100'. This prevents short circuits between the multiple electrodes 200 and improves the stability of the electrode assembly 10'.

[0153] Furthermore, since the thickness of the base material 140 is constant, the alignment of the multiple electrodes 200 can be made more precise. Therefore, the space between the base material 140 and the multiple electrodes 200 can be minimized, the energy density of the electrode assembly 10' can be further improved, and the cooling of the multiple electrodes 200 can be performed more efficiently.

[0154] Figure 12 is an exploded perspective view of a secondary battery including an electrode assembly according to one embodiment of the present invention, and Figure 13 is a schematic diagram of a battery module including the secondary battery shown in Figure 12.

[0155] Figure 12 will be explained with reference to an electrode assembly 10 according to one embodiment of the present invention. Therefore, those skilled in the art will be able to easily understand electrode assemblies 10' (see Figure 10) according to other embodiments of the present invention.

[0156] An electrode assembly 10 according to one embodiment of the present invention may be provided with a plurality of electrode tabs 210. Each electrode tab 210 can be connected to a plurality of electrodes 200 included in the electrode assembly 10 and can protrude in a direction that does not interfere with the sealing portion 120 and the sub-sealing portion 130.

[0157] Multiple electrode tabs 210 can be connected to leads 220. The leads 220 can be joined to the multiple electrode tabs 210 by spot welding or the like, and together with the multiple electrode tabs 210, they can serve as a passage for supplying power to the outside of the electrode assembly 10.

[0158] A portion of the periphery of the lead 220 can be surrounded by an insulating member 230. For example, the insulating member 230 can be an insulating tape. The insulating member 230 can insulate the lead 220 from the terrace 24 of the pouch-type battery case 20, which will be described later, and a portion of the lead 220 can protrude to the outside of the pouch-type battery case 20.

[0159] The electrode assembly 10 can be housed in a pouch-type battery case 20 (hereinafter referred to as "battery case") to form a secondary battery 1. In other words, the secondary battery 1 can include the electrode assembly 10 and the battery case 20.

[0160] On the other hand, the battery case 20 can be formed by sealing a pair of cases 21 connected to the folding section 22 together. The configuration of each case 21 described below will be explained based on the state in which the battery case 20 is unfolded. The "state in which the battery case 20 is unfolded" means the state in which the battery case 20 is unfolded as shown in Figure 12 by releasing any predetermined adhesives or seals that were present on the battery case 20.

[0161] Each case 21 may include a cup portion 23 having an indented shape and a terrace 24 extending around the periphery of the cup portion 23. However, it is not limited to this, and it goes without saying that the cup portion 23 may be formed on only one of the pair of cases 21.

[0162] With the electrode assembly 10 placed on one of the cup portions 23, the battery case 20 can be folded around the folding portion 22, and the terraces 24 of the pair of cases 21 can come into contact with each other and be sealed. Thus, the electrode assembly 10 can be stored in the storage space formed by the pair of cup portions 23.

[0163] Furthermore, the portion of the sealed terraces 24 located on the opposite side of the folding portion 22 can be folded at least once, for example, to form a double-sided folding (DSF). This is a well-known technique and will be easily understood by those skilled in the art.

[0164] The sealing portion 120 of the electrode assembly 10 can be positioned to face the folding portion 22 of the battery case 20. More specifically, the sealing portion 120 of the electrode assembly 10 can face the outer wall on the folding portion 22 side of the multiple outer walls forming the periphery of the cup portion 23. In addition, the sub-sealing portion 130 of the electrode assembly 10 can face the outer wall located on the opposite side of the folding portion 22 of the multiple outer walls forming the periphery of the cup portion 23.

[0165] In the case of the electrode assembly 10' according to another embodiment of the present invention (see Figure 10), the base material portion 140 can be positioned to face the folding portion 22 of the battery case 20. More specifically, the base material portion 140 of the electrode assembly 10' can face the outer wall on the folding portion 22 side of the plurality of outer walls forming the periphery of the cup portion 23. Also, the sub-sealing portion 150 of the electrode assembly 10' can face the outer wall located on the opposite side of the folding portion 22 of the plurality of outer walls forming the periphery of the cup portion 23.

[0166] On the other hand, the battery module 5 may include a plurality of secondary batteries 1 stacked on top of each other, and a housing 51 that houses the plurality of secondary batteries 1.

[0167] A cooling section 52 with high thermal conductivity may be provided on the inner bottom surface of the housing 51, and each secondary battery 1 may be positioned upright so that its folding section 22 is in contact with the cooling section 52. For example, the cooling section 52 may contain thermal grease.

[0168] As described above, the terrace 24 located on the opposite side of the folding portion 22 in the battery case 20 is folded at least once, and therefore may be relatively thicker than the folding portion 22. For this reason, in order to efficiently dissipate heat from the multiple electrodes 200 included in the electrode assembly 10, it is more effective to bring the folding portion 22 into contact with the cooling portion 52.

[0169] Furthermore, referring to Figure 5, the thickness of the sealing portion 120 can be made thinner overall than the thickness of the sub-sealing portion 130. Therefore, by arranging the sealing portion 120 of the electrode assembly 10 to face the folding portion 22 of the battery case 20, multiple electrodes 200 can be efficiently heat-dissipated.

[0170] Similarly, referring to Figure 10, the thickness of the base material portion 140 can be made generally thinner than the thickness of the sub-sealing portion 150. Therefore, by arranging the base material portion 140 of the electrode assembly 10' according to another embodiment of the present invention so as to face the folding portion 22 of the battery case 20, multiple electrodes 200 can be efficiently heat-dissipated.

[0171] In particular, since the base material portion 140 of the electrode assembly 10' according to another embodiment of the present invention is thin and uniform in thickness, the heat dissipation efficiency of the multiple electrodes 200 can be further improved compared to the electrode assembly 10 according to one embodiment.

[0172] The above description is merely illustrative of the technical concept of the present invention, and any person with ordinary skill in the art to which the present invention belongs can make various modifications and alterations without departing from the essential characteristics of the present invention.

[0173] Therefore, the embodiments disclosed in this invention are for illustrative purposes only, and not to limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by such embodiments.

[0174] The scope of protection of this invention shall be interpreted in accordance with the following claims, and all technical ideas within an equivalent scope shall be interpreted as being included within the scope of the rights of this invention. [Explanation of symbols]

[0175] 100 Separator Laminate 110 Separator 111 Base Separator 112 Main Separator 120 Sealing section 130 Sub-sealing section 140 Base material part 150 Sub-sealing section

Claims

1. A base separator having a pair of first edges extending in a first direction and a pair of second edges extending in a second direction perpendicular to the first direction, A base portion is provided in the central part of the base separator in the first direction and is formed to extend in the second direction, A separator laminate comprising a plurality of main separators having fixed edges connected to the base material portion, The separator laminate is configured to be folded around the base material portion, with the base material portion located on one side of the folded separator laminate and the second edge located on the other side.

2. The separator laminate according to claim 1, wherein, with respect to the first direction, some of the plurality of main separators spread to one side and other parts spread to the other side.

3. The separator laminate according to claim 1, wherein in the plurality of main separators, the non-fixed edges located on the opposite side of the fixed edges are located inward toward the upward direction with respect to the stacking direction.

4. A substrate portion located in the center of the base separator has one edge of multiple main separators fixed to it, and a separator laminate is folded around the substrate portion, It includes a plurality of electrodes inserted between the base separator and the plurality of main separators, The base material is an electrode assembly located on one side of the plurality of electrodes.

5. The electrode assembly according to claim 4, wherein the plurality of electrodes are in contact with or adjacent to the base material.

6. The electrode assembly according to claim 4, wherein the thickness of the base material is constant with respect to the stacking direction of the plurality of main separators.

7. The electrode assembly according to claim 4, wherein the base material portion is flat or bent or folded in a convex shape toward the outside of the separator laminate.

8. The separator laminate has a sub-sealing portion formed on the other side of the plurality of electrodes, where the base separator and the plurality of main separators are fused to each other. The electrode assembly according to claim 4, wherein the sub-sealing portion has an asymmetrical shape with respect to the base material portion.

9. The steps include: preparing a separator laminate in which one edge of multiple main separators is fixed to a substrate portion located in the center of a base separator; The steps include folding the separator laminate around the base material portion, A method for manufacturing an electrode assembly, comprising the step of inserting a plurality of electrodes between the base separator and a plurality of main separators.

10. The method for manufacturing an electrode assembly according to claim 9, further comprising the step of sealing the edges of the base separator and the plurality of main separators that are located opposite to the base material portion.

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