Secondary battery, apparatus for manufacturing secondary battery, and method for manufacturing secondary battery

Abstract

This disclosure provides a secondary battery. [Solution] The secondary battery of the present disclosure includes an electrode assembly, a main body portion having one open side for housing the electrode assembly, a cover that seals the electrode assembly while covering the open side of the main body portion, and a case including a sealing portion in which the main body portion and the outer peripheral surface of the cover are in contact. The sealing portion may include a top sealing portion extending in a first direction from the top surface of the case, a plurality of side sealing portions extending in a second direction intersecting the first direction and in the opposite direction from the side surface of the case, and a corner sealing portion that overlaps in the first direction when each of the top sealing portion and the plurality of side sealing portions is folded in a third direction intersecting each of the first and second directions.

Description

Technical Field

[0001] The present disclosure relates to a secondary battery, an apparatus for manufacturing a secondary battery, and a method for manufacturing a secondary battery.

Background Art

[0002] A secondary battery is a battery that can be charged and discharged, unlike a primary battery that cannot be charged. Low-capacity secondary batteries are used in portable small electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, and high-capacity secondary batteries are widely used as power sources for motor drives such as hybrid vehicles and electric vehicles, and batteries for power storage. Such secondary batteries include an electrode assembly composed of a positive electrode and a negative electrode, a case for housing the same, and electrode terminals connected to the electrode assembly.

[0003] In the case of a FPCB (Flexible Printed Circuit Board) electrically connected to the electrodes of the electrode assembly in a secondary battery, it may be advantageous from the viewpoint of energy density that the extending path is formed adjacent to the case that houses the electrode assembly. However, in the case of a pouch-type secondary battery, it is sealed by welding between the case and the cover, and the sealed portion where the welding is performed extends outside the case. Therefore, the FPCB does not extend linearly adjacent to the case, and there is a possibility that the extending path may be迂回 to avoid the sealed portion. Therefore, in order to structurally solve such a problem, it may be necessary to increase the energy density by reducing the overall length of the battery pack.

[0004] The above-described information disclosed in the background art of such an invention is only for improving the understanding of the background of the present invention, and thus may include information that does not constitute the prior art.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] The problem that this disclosure aims to solve is to provide a secondary battery in which the FPCB, connected to the lead tabs, extends in a straight line along the periphery of the case.

[0007] The problem that this disclosure aims to solve is to provide an apparatus for manufacturing secondary batteries that performs a process of folding the sealing portion (terrace) generated during the manufacturing process of secondary batteries toward the case side.

[0008] The problem that this disclosure aims to solve is to provide a method for manufacturing a secondary battery that includes a step of folding the sealing portion to ensure an extended path for the FPCB.

[0009] However, the technical problems that this invention aims to solve are not limited to those mentioned above, and other problems not mentioned should be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0010] A secondary battery according to one embodiment of the present disclosure for solving technical problems includes an electrode assembly, a main body portion having one open side for housing the electrode assembly, a cover that seals the electrode assembly while covering the open side of the main body portion, and a case including a sealing portion in which the main body portion and the outer peripheral surface of the cover are in contact. The sealing portion may include a top sealing portion extending in a first direction from the top surface of the case, a plurality of side sealing portions extending in a second direction intersecting the first direction and in the opposite direction from the side of the case, and a corner sealing portion that overlaps in the first direction when each of the top sealing portion and the plurality of side sealing portions is folded in a third direction intersecting each of the first and second directions.

[0011] A secondary battery manufacturing apparatus according to one embodiment of the present disclosure for solving technical problems includes a main body that has one open side for housing an electrode assembly, a cover that seals the electrode assembly while covering the open side of the main body, a guide block for fixing the case which includes a sealing portion in contact with the outer peripheral surface of the main body and the cover, a push block that pressurizes the case from the opposite side of the guide block, and a roller that rotates on the upper sealing portion located on the upper surface of the case and folds the upper sealing portion.

[0012] A method for manufacturing a secondary battery according to one embodiment of the present disclosure for solving technical problems includes an electrode assembly, a main body portion having one open side for housing the electrode assembly, a cover that seals the electrode assembly while covering the open side of the main body portion, and a case including a sealing portion in which the main body portion and the outer peripheral surface of the cover are in contact, and the method for manufacturing a secondary battery includes the steps of folding each of a plurality of side sealing portions of the sealing portion that extend from the side of the case in a second direction in a third direction intersecting the second direction so as to be adjacent to the case, a step of applying pressure to an upper sealing portion of the sealing portion that extends from the upper surface of the case in a first direction intersecting the second and third directions in the opposite direction to the first direction, and a step of folding a plurality of corner sealing portions of the sealing portion in the second direction and the opposite direction to the second direction as the upper sealing portion is folded in the third direction by the rotational movement of each of a plurality of rollers. [Effects of the Invention]

[0013] According to one embodiment of the present invention, by folding the sealing portion on the edge side of the case, interference with the extension path of the FPCB can be prevented, thereby reducing the overall length of the pack.

[0014] According to one embodiment of the present invention, an increase in energy density can be expected due to a reduction in the volume of the battery pack.

[0015] However, the effects obtained by this disclosure are not limited to those described above, and other technical effects not mentioned should be clearly understood by those skilled in the art from the description of the invention below.

Brief Description of Drawings

[0016] The following drawings and the like attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described later, serve to further understand the technical idea of the present invention. Therefore, the present invention should not be construed as being limited only to the matters described in such drawings.

[0017] [Figure 1] It is a diagram showing that an electrode assembly of a secondary battery according to an embodiment of the present disclosure is built in a case. [Figure 2] It is a perspective view of a secondary battery according to an embodiment of the present disclosure. [Figure 3] It is a separated perspective view showing a case, an FPCB (Flexible Printed Circuit Board), and a PCM (Protection Circuit Module) separated from each other according to an embodiment of the present disclosure. [Figure 4] It is a diagram showing a secondary battery in which a seal part according to an embodiment of the present disclosure is developed. [Figure 5] It is a developed view showing a folding area in a seal part and a cover according to an embodiment of the present disclosure. [Figure 6] It is a diagram schematically showing a manufacturing apparatus for manufacturing a secondary battery according to an embodiment of the present disclosure. [Figure 7] It is a diagram showing that a bent part is formed in an upper surface seal part by a first push block according to an embodiment of the present disclosure. [Figure 8] It is a diagram showing a manufacturing process of a secondary battery according to an embodiment of the present disclosure. [Figure 9] It is a diagram showing that a side surface seal part is folded according to an embodiment of the present disclosure. [Figure 10] It is a diagram showing that an upper surface seal part is pressed by a first push block according to an embodiment of the present disclosure. [Figure 11] It is a diagram showing a folded part folded by a first roller and a second roller according to an embodiment of the present disclosure. [Figure 12] A diagram showing that a lead tab according to an embodiment of the present disclosure is folded. [Figure 13] A diagram showing that a top seal portion and a side seal portion according to an embodiment of the present disclosure are folded in a third direction to form a folding portion. [Figure 14] A diagram showing a folding portion composed of a first folding portion, a second folding portion, and a third folding portion according to an embodiment of the present disclosure. [Figure 15] A diagram showing the state of extension of a conventional FPCB. [Figure 16] A diagram showing the state of extension of an FPCB according to an embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0018] <Summary of the Invention> According to an embodiment of the present disclosure, the corner seal portion can be formed by folding in the reverse direction of the second direction.

[0019] According to an embodiment of the present disclosure, the corner seal portion that overlaps in the first direction and is formed in the reverse direction of the second direction can be disposed above the top seal portion folded in the third direction.

[0020] According to an embodiment of the present disclosure, each of the top seal portion and the plurality of side seal portions is folded in a third direction along a folding region, and the folding region includes a first folding region that is a reference for each of the plurality of side seal portions to be folded in the third direction, a second folding region extending from the first folding region, and a third folding region that is a reference for the top seal portion to be folded in the third direction.

[0021] According to one embodiment of the present disclosure, the corner seal portion includes a plurality of corner seal portions, and the folding region may include a fourth folding region which is a reference for each of the plurality of corner seal portions to be folded in a second direction and in the opposite direction to the second direction after the plurality of corner seal portions have been folded in a third direction using a second folding region, and a fifth folding region which is a reference for folding within the corner seal portion when each of the plurality of corner seal portions is folded based on the fourth folding region.

[0022] According to one embodiment of the present disclosure, the fourth folding region can be positioned above the third folding region in the first direction.

[0023] According to one embodiment of the present disclosure, the fifth folding region can extend from the upper end of the sealing portion to the second folding region.

[0024] According to one embodiment of the present disclosure, each of the multiple corner seal portions can be superimposed in a first direction by being folded based on a fourth folding region and a fifth folding region.

[0025] According to one embodiment of the present disclosure, when a first lead tab connected to a plurality of first electrode tabs of an electrode assembly and a second lead tab connected to a plurality of second electrode tabs of an electrode assembly each extend in a first direction and the top seal portion is folded in a third direction, each of the first lead tab and the second lead tab is folded once together in the third direction, and the first lead tab and the second lead tab that have been folded once are folded again in the opposite direction to the third direction.

[0026] According to one embodiment of the present disclosure, the first and second lead tabs, which are folded again, can be electrically connected to an FPCB (Flexible Printed Circuit Board), and the FPCB can be formed extending in a second direction.

[0027] According to one embodiment of the present disclosure, the guide block includes a first guide block that supports at least a portion of the bottom surface of the case in a first direction and a second guide block that supports at least a portion of the side surface of the case in the opposite direction to a second direction, and the push block may include a first push block that presses the top of the case from the opposite side of the first guide block in the opposite direction to the first direction to bend the top seal portion and a second push block that presses the side of the case from the opposite side of the second guide block in a second direction to fold each of a plurality of side seal portions located on the side surface of the case.

[0028] According to one embodiment of the present disclosure, the width of the first push block in the second direction can be formed to be narrower than the width of the upper sealing portion in the second direction.

[0029] According to one embodiment of the present disclosure, the rollers may include a first roller and a second roller that fold the top seal portion while rotating from both ends of the top seal portion towards the central region of the top seal portion, respectively.

[0030] According to one embodiment of the present disclosure, the secondary battery includes a first lead tab connected to a plurality of first electrode tabs of an electrode assembly and extending in a first direction, and a second lead tab connected to a plurality of second electrode tabs of an electrode assembly and extending in a first direction, wherein the step of folding a plurality of corner seal portions of the seal portion in a second direction and in the opposite direction of the second direction includes the step of folding each of the first lead tab and the second lead tab together once in the third direction when the top seal portion is folded in a third direction, and the method may further include the step of folding the first and second lead tabs that have been folded once once again in the opposite direction of the third direction, and the step of electrically connecting the first and second lead tabs that have been folded once again to an FPCB (Flexible Printed Circuit Board) formed extending in a second direction.

[0031] According to one embodiment of the present disclosure, the FPCB extends along the top surface of the case from a first lead tab and a second lead tab.

[0032] According to one embodiment of the present disclosure, the roller can be moved under pressure only for a section of 1.3 mm to 1.7 mm from the upper end of the upper seal portion, or 70% to 80% of the height of the upper end of the upper seal portion.

[0033] According to one embodiment of the present disclosure, the corner seal portion is folded so as to be adjacent to the top surface of the case.

[0034] According to one embodiment of the present disclosure, each of the top seal portion and a plurality of side seal portions is folded in a third direction along a folding region, the folding region including a first folding region which is a reference for each of the plurality of side seal portions to be folded in the third direction, a second folding region extending from the first folding region, and a third folding region which is a reference for the top seal portion to be folded in the third direction, the corner seal portion includes a plurality of corner seal portions and may include a fourth folding region which is a reference for each of the plurality of corner seal portions to be folded in the opposite direction to the second direction after the plurality of corner seal portions have been folded in the third direction using the second folding region, and a fifth folding region which is a reference for folding within the corner seal portion when each of the plurality of corner seal portions is folded based on the fourth folding region.

[0035] <Detailed description of the invention> Preferred embodiments of this disclosure will now be described in detail based on the accompanying drawings. First, terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary and dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors may define the concepts of terms as appropriate to best describe their invention. Accordingly, it should be understood that the embodiments and configurations shown in the drawings described herein represent only a selection of preferred embodiments of the present invention and do not represent the entirety of the technical idea of ​​the present invention, and that there may be a variety of equivalents and modifications that can substitute for them at the time of filing this application.

[0036] Furthermore, as used herein, “comprise,” “comprising,” “include,” and “including” specify the presence of the shapes, figures, steps, actions, members, elements, and / or groups mentioned, and do not exclude the presence or addition of one or more other shapes, figures, actions, members, elements, and / or groups. Also, when describing embodiments of the present invention, “may be,” and “may include,” “one or more embodiments of the present invention.”

[0037] Furthermore, to aid in understanding the invention, the accompanying drawings may not be shown to actual scale, and the dimensions of some components may be exaggerated. Also, the same component will be assigned the same reference numeral in different embodiments.

[0038] The statement that two comparison subjects are "identical" means that they are "substantially identical." Therefore, being substantially identical may include having deviations that are considered low in this industry, for example, deviations of 5% or less. Furthermore, the uniformity of a parameter within a given domain can mean that it is uniform on average.

[0039] While terms like "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from another, and unless otherwise stated, the first component can be the second component.

[0040] Throughout this specification, unless otherwise stated, each component may be singular or plural.

[0041] When we say that any component is placed "above (or below)" or "above (or below)" a component, it means not only that the component is placed in contact with the top (or bottom) surface of the component, but also that other components may be interposed between the component and any component placed above (or below) it.

[0042] Furthermore, when it is stated that one component is "linked," "joined," or "connected" to another component, it must be understood that these components can be directly linked or connected to one another, but that other components can also "intersect" between them, or that components can be "linked," "joined," or "connected" through other components.

[0043] Furthermore, when we say that one part is electrically coupled to another part, this includes not only cases where they are directly connected, but also cases where other elements are in between to form the connection.

[0044] Throughout this specification, when we refer to "A and / or B," we mean A, B, or A and B unless otherwise specified. That is, "and / or" includes all combinations or any combination of the listed items. When we refer to "C through D," we mean C or greater and D or less, unless otherwise specified.

[0045] Figure 1 shows that the electrode assembly 20 of a secondary battery 100 according to one embodiment of the present disclosure is housed in a case. Referring to Figure 1, the electrode assembly 20 is provided in an internal space formed by the coupling between the main body 110 and the cover 120. A sealing portion is provided in the area where the cover 120 and the main body 110 are in contact. The sealing portion may include an upper sealing portion 120b, a side sealing portion 120a, and a corner sealing portion 120c formed on the periphery of the case. Here, the direction in which the upper sealing portion 120b extends from the case can be defined as the first direction D1, the direction in which the side sealing portion 120a extends from the case can be defined as the second direction D2, and the direction in which the upper sealing portion 120b and the side sealing portion 120a are folded can be defined as the third direction D3.

[0046] On the other hand, a typical pouch-type secondary battery 100 may include an electrode assembly 20 and a case for housing the electrode assembly 20. The case may be in pouch form. The electrode assembly 20 may include a positive electrode plate which is a first electrode plate 11, a negative electrode plate which is a second electrode plate 12, and a separator 13 interposed between them. Alternatively, the first electrode plate 11 may be the negative electrode plate and the second electrode plate 12 may be the positive electrode plate, or the first electrode plate 11 may be the positive electrode plate and the second electrode plate 12 may be the negative electrode plate.

[0047] The first electrode plate 11 is provided with a first electrode tab 11-1 electrically connected to the blank portion of the first electrode, and the second electrode plate 12 is provided with a second electrode tab 12-1 electrically connected to the blank portion of the second electrode. The first electrode tab 11-1 and the second electrode tab 12-1 can be electrically connected to the outside by welding them to the first lead tab 111-1 and the second lead tab 111-2, respectively. Tab films can be attached to the first lead tab 111-1 and the second lead tab 111-2 for insulation from the case.

[0048] The case can be sealed by bringing the sealing portion at the end into contact with the electrode assembly 20. At this time, the case can be sealed with the tab film positioned between the sealing portions. As shown in Figure 1, the tab film can be attached to the first electrode tab 11-1 and the second electrode tab 12-1, respectively.

[0049] The sealing portion of the case may consist of a heat-sealable material, with the heat-sealable layers being bonded together to create a seal. Since heat-sealable materials generally have weak adhesion to metals, a thin film-like tab film is attached to the electrode tab and fused to the case.

[0050] Referring to Figure 1, the electrode assembly 20 can be formed by stacking unit cells 10, which include a first electrode plate 11 on which a first electrode tab 11-1 is formed, a second electrode plate 12 on which a second electrode tab 12-1 is formed, and a separator interposed between the first electrode plate 11 and the second electrode plate 12. Thus, in one embodiment, the electrode assembly 20 can be a stacked assembly. The electrode plates and electrode tabs can be formed in the form of thin plates or films. The electrode assembly 20 may correspond to a Z-stack electrode assembly in which the first electrode plate 11 and the second electrode plate 12 are inserted on both sides of a separator bent into a Z-stack. The shape of the electrode assembly is not limited in the present invention.

[0051] Multiple electrode assemblies 20 can be stacked so that their long sides are adjacent to each other and housed separately in a case, but the number of electrode assemblies is not limited in this invention.

[0052] The first electrode tab 11-1 and the second electrode tab 12-1 can be located on the same side of the electrode assembly 20. For example, the first electrode tab 11-1 and the second electrode tab 12-1 can be formed on the same side of the electrode assembly 20 that is parallel to the stacking direction of the unit cells 10 of the electrode assembly 20. Alternatively, the first electrode tab 11-1 and the second electrode tab 12-1 can be located on different sides. For example, the first electrode tab 11-1 can be located on the left end face of the electrode assembly 20 that is parallel to the stacking direction of the unit cells 10 of the electrode assembly 20, and the second electrode tab 12-1 can be located on the right end face of the electrode assembly 20. The left and right sides are based on the secondary battery 100 shown in Figure 1 for convenience of explanation, and their positions may change when the secondary battery 100 rotates left and right or up and down.

[0053] The electrode assembly 20 can be housed in a case together with the electrolyte. The electrode assembly 20 can also have the first lead tab 111-1 and the second lead tab 111-2 connected to the first electrode tab 11-1 of the first electrode plate 11 and the second electrode tab 12-1 of the second electrode plate 12, respectively. The first current collector and the second current collector can be welded and connected to the first lead tab 111-1 and the second lead tab 111-2, respectively.

[0054] According to one embodiment of the present disclosure, the tape 15 can be attached to the front surface of the electrode assembly 20 perpendicular to the stacking direction of the unit cells 10 of the electrode assembly 20. For example, the tape 15 can be attached to the edge of the electrode assembly 20 in the direction in which the first electrode tab 11-1 or the second electrode tab 12-1 is located, on the front surface of the electrode assembly 20 perpendicular to the stacking direction of the unit cells 10 of the electrode assembly 20. Alternatively, the tape 15 can be attached to the edge of the electrode assembly 20 in the direction in which the first electrode tab 11-1 or the second electrode tab 12-1 is located, on the back surface of the electrode assembly 20 perpendicular to the stacking direction of the unit cells 10 of the electrode assembly 20. The front surface or back surface of the electrode assembly 20 is used to distinguish between two surfaces of the electrode assembly 20 perpendicular to the stacking direction of the unit cells 10 of the electrode assembly 20, and does not necessarily mean a surface facing forward or backward. The front or back surface of the electrode assembly 20 may be referred to as the first or second surface of the electrode assembly 20 perpendicular to the stacking direction.

[0055] Although the electrode assembly 20 in Figure 1 is described as a laminated type, it is not limited to this and may be manufactured in a jelly roll shape.

[0056] Figure 2 is a perspective view of a secondary battery 100 according to one embodiment of the present disclosure. Figure 3 is a separated perspective view showing the case, FPCB(130), and PCM(140) separately according to one embodiment of the present disclosure. Referring to Figures 2 and 3, according to one embodiment of the present disclosure, the lead tab 111, including the first and second lead tabs which are folded again, is electrically connected to the FPCB(130), and the FPCB(130) can be formed extending in a second direction D2. As shown in Figure 2, the FPCB(130) can extend in contact with the case. In this example, the extension path of the FPCB(130) is changed by folding along the case, but it can also extend linearly in the second direction D2.

[0057] In the electrode assembly 20, a pair of lead tabs 111 exposed from the case are electrically connected to an FPCB(130) on the upper surface of the case by contact, and the FPCB(130) can be connected to a PCM(140) on the upper surface of the case. Here, the electrical contact between the lead tabs 111 and the FPCB(130) is made on the upper surface of the case by folding the lead tabs 111 onto the upper surface of the case. In this example, where the pair of lead tabs 111 are spaced apart from each other at a predetermined distance, the PCM(140) can be positioned between them and connected to the FPCB(130).

[0058] The FPCB(130) may have at least a section that extends in contact with the case, and as described above, in the process of folding the seal portion, the corner seal portion 120c can form a folded portion (F) that folds onto the upper surface of the case. With this structure, the FPCB(130) can extend in contact with the case without having to extend while avoiding the seal portion.

[0059] Figure 4 shows a secondary battery 100 with a sealed portion unfolded according to one embodiment of the present disclosure. Referring to Figure 4, the sealed portion formed by the contact of the main body 110 and the cover 120 can be unfolded around the periphery of the main body 110 before being folded. A portion of the lead tab 111 that extends to the outside of the case can be located inside the upper sealed portion 120b. Here, the sealed portion is folded along the folding area shown in Figure 5 below.

[0060] Figure 5 is an exploded view showing the folding areas of the seal portion and cover 120 according to one embodiment of the present disclosure. Referring to Figure 5, the seal portion formed on the periphery of the cover 120 is folded in a third direction D3 so as to abut or be adjacent to the main body portion 110. Specifically, the top seal portion 120b is folded in a third direction D3 along the third folding area 123, and the side seal portion 120a is folded in a third direction D3 along the first folding area 121. Here, the pair of corner seal portions 120c are folded in a second direction D2 and the opposite direction of the second direction D2, respectively, along the fourth folding area 124 and the fifth folding area 125, by the folding of the top seal portion 120b and the side seal portion 120a, to be adjacent to the top surface of the case, as an overlapping surface is formed. Furthermore, the fifth folding region 125 and the second folding region 122 can be superimposed by the corner seal portion 120c being folded onto the top surface of the case. Through such superimposition, two of the multiple layers of the folding portion (F) can be part of the corner seal portion 120c. Here, the region superimposed by the folding of the corner seal portion 120c can be located above the folded top seal portion 120b.

[0061] More specifically, the folding region may include a first folding region 121 which is the reference for folding the side seal portion 120a in a third direction D3, a fourth folding region 124 which is the reference for folding the corner seal portion 120c so that it is adjacent to the top surface of the case, a fifth folding region 125 which is the reference for folding within the area of ​​the corner seal portion 120c, and a third folding region 123 which is the reference for folding the second folding region 122 and the top seal portion 120b in a third direction D3. Here, the second folding region 122 can be formed on the same line as the first folding region 121 on the first direction D1 side. The fifth folding region 125 extends in a direction that crosses the corner seal portion 120c, but one end can be in contact with the ends of the second folding region 122 and the fourth folding region 124. Here, the fourth folding region 124 can be positioned above the third folding region 123 in the first direction D1.

[0062] Figure 6 is a simplified diagram showing a manufacturing apparatus 200 for manufacturing a secondary battery 100 according to one embodiment of the present disclosure. Figure 7 is a diagram showing that a bent portion 126 is formed on the upper seal portion 120b by a first push block 202 according to one embodiment of the present disclosure. Referring to Figures 6 and 7, the manufacturing apparatus 200 for the secondary battery 100 may include a guide block for fixing the case of the secondary battery 100, a push block for applying pressure to the case from the opposite side of the guide block, and a roller that rotates on the upper seal portion 120b located on the upper surface of the case and folds the upper seal portion 120b.

[0063] Here, the guide block includes a first guide block 201 that supports at least a portion of the bottom surface of the case in a first direction D1, and a second guide block 203 that supports at least a portion of the side surface of the case in a second direction D2 and the opposite direction. The push block may include a first push block 202 that presses the top of the case from the opposite side of the first guide block 201 in the opposite direction of the first direction D1 to bend the top seal portion 120b, and a second push block 204 that presses the side of the case from the opposite side of the second guide block 203 in the second direction D2 to fold the side seal portion 120a located on the side of the case.

[0064] The width of the first push block 202 in the second direction D2 can be formed to be narrower than the width of the top seal portion 120b in the second direction D2. This is because, since the side seal portion 120a is folded in the third direction D3 along the first folding region 121, there is a risk that the side seal portion 120a may be damaged without being folded due to the pressure transmitted in the pressurizing direction 202' in the third direction D3. Furthermore, the pressurizing direction 202' can be set so that the top seal portion 120b is bent in the opposite direction to the first direction D1 and partially folded in the third direction D3. That is, the top seal portion 120b is bent. The section to which the pressurizing force is directly transmitted is formed from the center of the top seal portion 120b in the second direction D2 and the opposite direction to the second direction D2, but may be a section that is separated from the side seal portions 120a located on both sides by a predetermined distance.

[0065] On the other hand, the rollers, including the first roller 211 and the second roller 212, can fold the top seal portion 120b by rotating from both ends of the top seal portion 120b towards the central region of the top seal portion 120b. Specifically, the corner seal portion 120c is folded onto the top surface of the case, so the corner seal portion 120c located on the left side in the illustration is folded by the first roller 211, which folds it in the opposite direction of the second direction D2. The corner seal portion 120c located on the right side in the illustration, which is folded in the second direction D2, is folded by the second roller 212. That is, the first roller 211 and the second roller 212 can rotate and enter the space above the case, and in the process of entering, they can pressurize the seal portion and fold it so that it is adjacent to the case side.

[0066] Here, the roller can be moved under pressure only for a distance of, for example, 1.3 mm to 1.7 mm from the upper end of the upper seal portion 120b, or 70% to 80% of the height of the upper end of the upper seal portion 120b. At this time, the height of the upper seal portion 120b can be 1.5 mm to 2.7 mm, and the distance between the main body portion 110 and the electrode assembly 20 housed within the main body portion 110 can be maintained at least 0.6 mm. This is a design that takes into account the thickness of the seal portion, and if pressure is applied only to the height of the upper seal portion 120b of the seal portion, there is a risk of damaging the electrode assembly 20 located inside the case due to deformation of the case, so pressure can be applied based on a distance shorter than the height of the upper seal portion 120b from the upper end of the upper seal portion 120b.

[0067] Figure 8 shows the manufacturing process of a secondary battery 100 according to one embodiment of the present disclosure. Referring to Figure 8, the method for manufacturing the secondary battery 100 includes the steps of folding the side seal portion 120a, which extends from the side of the case in a second direction D2 and the opposite direction of the second direction D2, in a third direction D3 so as to be adjacent to the case (S10), and the step of applying pressure to the top seal portion 120b, which extends from the top surface in a first direction D1, in the opposite direction of the first direction D1 (S20). The direction in which the top seal portion 120b is applied may be a direction slightly biased from the opposite direction of the first direction D1 to the third direction D3. Subsequently, the roller rotates in the second direction and the opposite direction of the second direction (S30). Due to this rotational movement, the top seal portion 120b and the lead tab 111 are folded once in the third direction D3. Subsequently, the lead tab 111 is folded so that the lead tab 111, which was folded once in the third direction D3 during the folding process of the upper seal portion 120b, is folded again in the opposite direction of the third direction D3 (S40).

[0068] The inner surface of the folded lead tab 111 can be electrically connected to the FPCB(130) (S50). That is, one side of the FPCB(130) can be in contact with the lead tab 111, and the opposite side can be in contact with the top seal portion 120b or the top surface of the case. Therefore, an insulator can be interposed on the opposite side. The FPCB(130) electrically connected to the lead tab 111 can be connected to the PCM(140) (S60).

[0069] Figure 9 shows how the side seal portion 120a according to one embodiment of the present disclosure is folded. Referring to Figures 6 and 9, each of the multiple side seal portions 120a arranged on both sides of the main body portion 110 is folded toward a third direction D3 by the second guide block 203 and the second push block 204. By folding each of the multiple side seal portions 120a toward the third direction D3, each of the multiple side seal portions 120a can be positioned to abut against or adjacent to the main body portion 110. With such folding, the corner seal portions 120c can be positioned to face each other.

[0070] Figure 10 shows that the top seal portion 120b according to one embodiment of the present disclosure is pressurized by the first push block 202. Referring to Figures 6 and 10, in the pressurizing step of the top seal portion 120b, the top seal portion 120b can be pressurized by the first push block 202 in a pressurizing direction 202' that includes at least the third direction D3. The pressurization by the first push block 202 causes the central part of the top seal portion 120b to be bent so as to be slightly biased towards the third direction D3. The bending of the top seal portion 120b can induce the top seal portion 120b to fold in the third direction D3 as the roller enters thereafter.

[0071] Figure 11 shows a folded portion (F) folded by a first roller 211 and a second roller 212 according to one embodiment of the present disclosure. Referring to Figures 6 and 11, by applying pressure to the corner seal portion 120c and the top seal portion 120b bent by the rotational movement of the first roller 211 and the second roller 212, not only is the top seal portion 120b folded in a third direction, but each of the corner seal portions 120c is folded in a second direction and in the opposite direction to the second direction. Referring to Figures 5 and 11, each of the corner seal portions 120c can be formed to overlap in the first direction D1 by being folded by a second folding region 122, a fourth folding region 124, and a fifth folding region 125. Each of the corner seal portions 120c formed in the second direction D2 and the opposite direction of the second direction D2 can be folded based on the fourth folding region 124 so that they are positioned above the top seal portion 120b folded in the third direction D3. That is, the corner seal portions 120c can be folded based on the fourth folding region 124 so that they can be superimposed on the top seal portion 120b in the first direction D1.

[0072] Figure 12 shows how a lead tab 111 according to one embodiment of the present disclosure is folded. Referring to Figure 12, when the top seal portion 120b is folded in the third direction D3, each of the first lead tab 111-1 and the second lead tab 111-2 is folded once in the third direction D3. In the FPCB coupling and positioning step, the first lead tab 111-1 and the second lead tab 111-2, which have been folded once in the third direction D3, are folded again in the opposite direction of the third direction D3. During the process of folding again, the inner surfaces of the FPCB and the folded lead tabs 111 can be electrically coupled.

[0073] Figure 13 shows that a folded portion (F) is formed when the top sealing portion 120b and the side sealing portion 120a according to one embodiment of the present disclosure are folded in a third direction. Figure 14 shows a folded portion (F) according to one embodiment of the present disclosure, consisting of a first folded portion (F1), a second folded portion (F2), and a third folded portion (F3). Referring to Figures 13 and 14, the folded portion (F) is formed when the top sealing portion 120b and the side sealing portion 120a are folded in the third direction D3, and the corner sealing portion 120c located at the boundary is folded along a plurality of folding regions. Due to the plurality of folding regions, the folded portion (F) can be configured in a form in which a plurality of layers are stacked in the first direction D1. Referring to Figure 14, the folding section (F) may include a first folding section (F1), a second folding section (F2), and a third folding section (F3) from the top end.

[0074] The first folding portion (F1) is one of two regions separated by the fifth folding region 125 as part of the corner seal portion 120c, and may be a region adjacent to the side seal portion 120a. The second folding portion (F2) is the remaining region of the corner seal portion 120c separated by the fifth folding region 125, and may be a region adjacent to the top seal portion 120b, and may be folded and positioned below the first folding portion (F1). The third folding portion (F3) may be a region of the top seal portion 120b located below the first folding portion (F1) and the second folding portion (F2). As in this example, the folding portion (F) can be configured in a form in which three layers are stacked.

[0075] For example, the corner seal portion 120c is folded so as to be adjacent to the top surface of the case. The folding area may include a first folding area 121 which is the reference for the side seal portion 120a to be folded in a third direction D3, a second folding area 122 which extends from the first folding area 121, and a third folding area 123 which is the reference for the top seal portion 120b to be folded in a third direction D3. It may also include a fourth folding area 124 which is the reference for the corner seal portion 120c to be folded in a second direction D2 and the opposite direction of the second direction D2, and a fifth folding area 125 which is the reference for folding within the corner seal portion 120c when the corner seal portion 120c is folded based on the second folding area 122.

[0076] Figure 15 shows the extension of a conventional FPCB(130'), and Figure 16 shows the extension of an FPCB(130) according to one embodiment of the present disclosure. Referring to Figure 15, the extension path of the FPCB(130') is bypassed by the seal portion, and this bypass path can increase the overall length and width of the battery pack. The increase in overall length and width can increase the capacity of the battery pack by, for example, about 9% or more depending on the design, which can induce a decrease in energy density. As a result, as disclosed in the present invention shown in Figure 16, by folding the seal portion to extend the FPCB(130) from the lead tab 111 along the case, the extension path of the FPCB(130) can be secured in a narrower space, thereby improving energy density.

[0077] Although the present invention has been described above with reference to limited embodiments and drawings, it is not limited thereto, and of course, a wide range of modifications and variations are possible within the equivalent scope of the technical concept and claims of the present invention by persons with ordinary skill in the art to which the present invention pertains. [Explanation of Symbols]

[0078] 10 unit cells 11 First electrode plate 11-1 First electrode tab 12. Second electrode plate 12-1 Second electrode tab 13 Separator 15 Tapes 20 Electrode assembly 100 Secondary battery 110 Main body 111 Lead Tabs 111-1 First lead tab 111-2 Second lead tab 120 Cover 120a Side seal section 120b Top sealing section 120c Corner seal section 121 First folding region 122 Second folding area 123 Third folding area 124 The fourth folding region 125 Fifth folding area 126 Bent section 130 FPCB 140 PCM 200 Manufacturing equipment 201 First guide block 202 First push block 202' Pressure direction 203 Second guide block 204 Second push block 211 The First Laura 212 The Second Laura S10 Folding of the side seal S20 Pressurization of the upper seal portion S30 Lola's entry S40 Lead tab folding S50 Connection and arrangement of FPCB S60 PCM connection F Folding part F1 First folding section F2 Second folding section F3 Third folding section D1 First direction D2 Second direction D3 Third direction

Claims

1. Electrode assembly and The case includes a main body portion having one open side for housing the electrode assembly, a cover that seals the electrode assembly while covering the open side of the main body portion, and a sealing portion in which the main body portion and the outer peripheral surface of the cover come into contact. The aforementioned sealing portion is An upper sealing portion extending in a first direction from the upper surface of the case, A plurality of side sealing portions extending from the side of the case in a second direction intersecting the first direction and in the opposite direction to the second direction, A secondary battery comprising: a corner seal portion that overlaps the first direction when each of the upper seal portion and the plurality of side seal portions is folded in a third direction that intersects the first direction and the second direction, respectively.

2. The secondary battery according to claim 1, wherein the corner seal portion is formed by folding in the opposite direction to the second direction.

3. The secondary battery according to claim 1, wherein the corner seal portion, which is superimposed in the first direction and formed in the opposite direction to the second direction, is positioned above the upper seal portion that is folded in the third direction.

4. Each of the above-mentioned upper sealing portion and the plurality of side sealing portions is folded in the third direction along the folding area. The aforementioned folding area is, A first folding region which is a reference for each of the plurality of side sealing portions to be folded in the third direction, and a second folding region which extends from the first folding region, The secondary battery according to claim 2, comprising a third folding region which is a reference for the upper sealing portion to be folded in the third direction.

5. The aforementioned corner seal portion includes a plurality of corner seal portions, The aforementioned folding area is, After the plurality of corner seal portions are folded in the third direction using the second folding region, each of the plurality of corner seal portions is folded in the second direction and in the opposite direction to the second direction by a fourth folding region, The secondary battery according to claim 4, further comprising: a fifth folding region which is a reference for folding within the corner seal portion when each of the plurality of corner seal portions is folded based on the fourth folding region.

6. The secondary battery according to claim 5, wherein the fourth folding region is positioned above the third folding region in the first direction.

7. The secondary battery according to claim 6, wherein the fifth folding region extends from the upper end of the sealing portion to the second folding region.

8. The secondary battery according to claim 6, wherein each of the plurality of corner seal portions is folded based on the fourth folding region and the fifth folding region so as to overlap in the first direction.

9. Each of the first lead tabs connected to a plurality of first electrode tabs of the electrode assembly, and each of the second lead tabs connected to a plurality of second electrode tabs of the electrode assembly, extends in the first direction. The secondary battery according to claim 1, wherein when the upper sealing portion is folded in the third direction, each of the first lead tab and the second lead tab is folded once in the third direction, and the first lead tab and the second lead tab that have been folded once are folded one more time in the opposite direction to the third direction.

10. The secondary battery according to claim 9, wherein the further folded first lead tab and second lead tab are electrically connected to the FPCB, and the FPCB is formed extending in the second direction.

11. A case comprising: a main body with one side open to house an electrode assembly; a cover that seals the electrode assembly while covering the open side of the main body; and a guide block that fixes the case, including a sealing portion where the main body and the outer peripheral surface of the cover come into contact. A push block that pressurizes the case from the opposite side of the guide block, A secondary battery manufacturing apparatus, comprising: a roller that rotates and moves on the top surface of the case, folding the top surface seal portion; and a roller that folds the top surface seal portion.

12. The aforementioned guide block is A first guide block that supports at least a portion of the bottom surface of the case in a first direction, The case includes a second guide block that supports at least a portion of the side surface in the opposite direction to the second direction, The aforementioned push block is A first push block presses the upper part of the case from the opposite side of the first guide block in the opposite direction to the first direction, thereby bending the upper seal portion. A secondary battery manufacturing apparatus according to claim 11, comprising: a second push block that presses the side of the case in the second direction from the opposite side of the second guide block to fold each of a plurality of side seal portions located on the side of the case.

13. The secondary battery manufacturing apparatus according to claim 12, wherein the width of the first push block in the second direction is formed to be narrower than the width of the upper seal portion in the second direction.

14. The secondary battery manufacturing apparatus according to claim 12, wherein the rollers include a first roller and a second roller that fold the upper seal portion while rotating from both ends of the upper seal portion to the central region of the upper seal portion, respectively.

15. A method for manufacturing a secondary battery, comprising an electrode assembly, a main body having one open side for housing the electrode assembly, a cover that covers the open side of the main body while sealing the electrode assembly, and a case including a sealing portion in which the main body and the outer peripheral surface of the cover are in contact, The steps include folding each of the multiple side sealing portions of the sealing portion that extend from the side surface of the case in a second direction in a third direction intersecting the second direction so as to be adjacent to the case, The steps include applying pressure to the upper sealing portion of the sealing portion that extends from the upper surface of the case in a first direction intersecting the second and third directions, in the direction opposite to the first direction, A method for manufacturing a secondary battery, comprising the step of folding a plurality of corner seal portions of the seal portion in the second direction and the opposite direction of the second direction by the rotational movement of each of a plurality of rollers, thereby folding the upper seal portion in the third direction.

16. The secondary battery includes a first lead tab connected to a plurality of first electrode tabs of the electrode assembly and extending in the first direction, and a second lead tab connected to a plurality of second electrode tabs of the electrode assembly and extending in the first direction. The step of folding a plurality of corner seal portions of the seal portion in the second direction and the opposite direction of the second direction includes, when the upper seal portion is folded in the third direction, the step of folding each of the first lead tab and the second lead tab once in the third direction. The aforementioned manufacturing method is The first and second lead tabs, which have been folded once, are folded again in the opposite direction to the third direction. A method for manufacturing a secondary battery according to claim 15, further comprising the step of electrically connecting the further folded first lead tab and second lead tab to an FPCB formed extending in the second direction.

17. The method for manufacturing a secondary battery according to claim 16, wherein the FPCB extends from the first lead tab and the second lead tab along the upper surface of the case.

18. The method for manufacturing a secondary battery according to claim 15, wherein the roller is moved under pressure for a distance of 1.3 mm to 1.7 mm from the upper end of the upper sealing portion, or for a distance of 70% to 80% of the height of the upper end of the upper sealing portion.

19. The method for manufacturing a secondary battery according to claim 15, wherein the corner seal portion is folded so as to be adjacent to the upper surface of the case.

20. Each of the above-mentioned upper sealing portion and the plurality of side sealing portions is folded in the third direction along the folding area. The aforementioned folding area is, A first folding region which is a reference for each of the plurality of side sealing portions to be folded in the third direction, and a second folding region which extends from the first folding region, The upper sealing portion includes a third folding region which is a reference for folding in the third direction, The aforementioned corner seal portion includes a plurality of corner seal portions, After the plurality of corner seal portions are folded in the third direction using the second folding region, each of the plurality of corner seal portions is folded in the opposite direction to the second direction by a fourth folding region, A method for manufacturing a secondary battery according to claim 19, comprising: a fifth folding region which is a reference for folding within the corner seal portion when each of the plurality of corner seal portions is folded based on the fourth folding region.

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