Secondary battery

Abstract

A secondary battery includes an electrode assembly, a pouch accommodating the electrode assembly, and a cover tape attached to the pouch so as to at least partially cover at least two surfaces of the pouch. The cover tape includes a fixed region attached to the first surface of the pouch, a dot region attached to the second surface of the pouch, and an adhesive on the fixed region and the dot region, and the adhesive has different adhesive forces.

Description

Technical Field

[0001] Aspects of embodiments of the present disclosure relate to secondary batteries. Background Art

[0002] Unlike non-rechargeable primary batteries, secondary batteries are rechargeable and dischargeable batteries. Low-capacity secondary batteries can be used in portable small electronic devices (such as smartphones, feature phones, laptop computers, digital cameras, and video cameras), and high-capacity secondary batteries are widely used as power sources for driving motors and as batteries for power storage in hybrid vehicles, electric vehicles, etc. Such secondary batteries include an electrode assembly (which includes a positive electrode and a negative electrode), a case that houses the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] The information disclosed in this section is provided to enhance the understanding of the background art of the present disclosure, and thus, it may include information that does not form part of the related art. Summary of the Invention

[0004] According to an aspect of an embodiment of the present disclosure, there is provided a secondary battery capable of preventing (preventing or substantially preventing) the exposure of an adhesive of a cover tape that covers an outer surface of a battery cell.

[0005] However, the aspects and objectives of the present disclosure are not limited to the aspects and objectives described above, and those skilled in the art will clearly understand other aspects and objectives of the present disclosure from the following description.

[0006] According to one or more embodiments, a secondary battery includes an electrode assembly, a pouch that houses the electrode assembly, and a cover tape attached to the pouch to at least partially cover at least two surfaces of the pouch, wherein the cover tape includes a fixing region attached to a first surface of the pouch, a dot region attached to a second surface of the pouch, and an adhesive on the fixing region and the dot region, and the adhesive has different adhesive forces.

[0007] In one or more embodiments, the fixing region of the cover tape may cover a side surface of the pouch, and the dot region of the cover tape may cover at least a part of an upper surface of the pouch.

[0008] In one or more embodiments, the adhesive on the dot region may have an adhesive force smaller than that of the adhesive on the fixing region.

[0009] In one or more embodiments, the cover tape may include a base region attached to a lower surface of the pouch and having a first adhesive force.

[0010] In one or more embodiments, the cover tape may include: a first dot area extending from a side surface of the base area and having a second adhesive force; a second dot area on an edge of a part of the first dot area and having a first adhesive force; and a first fixing area on an edge of the second dot area and having a third adhesive force.

[0011] In one or more embodiments, the cover tape may include: a base area attached to a lower surface of the pouch and having a first adhesive force; a second fixing area extending from an opposite side surface of the base area and having a third adhesive force; and a third dot area extending along an outer side of the second fixing area and having a second adhesive force.

[0012] In one or more embodiments, the second adhesive force may be less than the first adhesive force.

[0013] In one or more embodiments, the third adhesive force may be greater than the first adhesive force.

[0014] In one or more embodiments, the first adhesive force may be 0.20 to 0.50 kgf / 25 mm.

[0015] In one or more embodiments, the second adhesive force may be 0.05 to 0.25 kgf / 25 mm.

[0016] In one or more embodiments, the third adhesive force may be 1.10 to 1.40 kgf / 25 mm.

[0017] In one or more embodiments, the cover tape may further include a termination area at an end of the first fixing area or the third dot area and no adhesive is applied to the termination area.

[0018] In one or more embodiments, the termination area may be on an outermost edge of the first fixing area or the third dot area.

[0019] In one or more embodiments, the termination area may have a thickness different from that of the base material of the cover tape.

[0020] In one or more embodiments, the termination area may be thicker than the base material of the cover tape and may contact an upper surface of the pouch. Description of the Drawings

[0021] The drawings incorporated in this specification illustrate some example embodiments, and further illustrate the technical aspects and concepts of the present disclosure in conjunction with the detailed description of some of the following embodiments; however, the present disclosure should not be construed as being limited to what is shown in the drawings.

[0022] Figure 1 is an exploded perspective view of a pouch cell type battery cell constituting a secondary battery according to an embodiment;

[0023] Figure 2 is a perspective view of a secondary battery according to an embodiment;

[0024] Figure 3 is Figure 2 an enlarged view of region "A" in

[0025] Figure 4 a plan view of a cover tape of a secondary battery according to an embodiment; and

[0026] Figure 5 is a side view when observed in the direction "B" in Figure 2 an enlarged view of region "A" in DETAILED DESCRIPTION

[0027] Herein, some embodiments will be described in more detail with reference to the accompanying drawings. It should be understood that the terms or words used in the specification and the appended claims should not be construed as limited to the general meaning and dictionary meaning, but should be interpreted based on the principle that allows the inventor to define appropriate terms for the best explanation, based on the meaning and concept according to the technical concept of the present disclosure. The embodiments described in this specification and the configurations shown in the drawings are provided as some example embodiments and do not necessarily represent all the technical concepts of the present disclosure. Therefore, it should be understood that various alternative equivalents and modifications may be possible when this application is filed. As used herein, the terms "comprising" (or "including") and / or "comprising... of" (or "including... of") are intended to indicate the presence of the stated drawings, numbers, steps, operations, components, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other drawings, numbers, steps, operations, components, elements, and / or groups. In addition, when describing an embodiment, the use of "may" may refer to "one or more embodiments".

[0028] The drawings may not be to scale, and some components may be exaggerated in size to assist in understanding the present disclosure. In various embodiments, the same components may be denoted by the same reference numerals.

[0029] A reference to two components being "equivalent" or "identical" means that they may be equivalent or substantially equivalent, or identical or substantially identical. Thus, substantially identical may include deviations that are considered low in the art (such as deviations of less than 5%). If a parameter is uniform in a given region, this may mean that the parameter is uniform from an average perspective.

[0030] Although various components may be described using "first", "second", etc., the components are not limited by these terms. These terms are used to distinguish one component from another, and the first component may be referred to as the second component unless otherwise stated.

[0031] Throughout the specification, each component may be singular or plural unless otherwise specified.

[0032] If any structure is provided "above" (or "below") a component or "on" (or "beneath") a component, this may mean not only that the structure is provided adjacent to the upper surface (or lower surface) of the component, but also that another structure may be interposed between the component and the structure provided on (or below) the component.

[0033] It should also be understood that if a component is described as "connected", "coupled" or "linked" to another component, the components may be directly connected or linked to each other, one or more other components may be "interposed" between the components, or the components may be "connected", "coupled" or "linked" to each other via one or more other components. When an element is said to be electrically coupled to another element, the element may be directly coupled to the other element or indirectly coupled to the other element via one or more intermediate elements.

[0034] Throughout the specification, a reference to "A and / or B" means A, B, or A and B unless otherwise specified. The term "and / or" refers to all combinations or any combination of a plurality of related listed items. A reference to "C to D" means C or higher and D or lower unless otherwise specified.

[0035] Here, a secondary battery according to an embodiment will be described in more detail.

[0036] Figure 1 is an exploded perspective view of a pouch-type battery cell constituting a secondary battery according to an embodiment.

[0037] In an embodiment, the battery cell 100 may be configured as a pouch-type battery and may include an electrode assembly, a first current collector, a first terminal, a second current collector, a second terminal, a case, and a cover assembly.

[0038] The battery cell may include an electrode assembly 110 and a pouch 130 that houses the electrode assembly 110.

[0039] The electrode assembly 110 may include a negative electrode plate 112 as a first electrode plate, a positive electrode plate 114 as a second electrode plate, and a separator 116 interposed between the negative electrode plate 112 and the positive electrode plate 114. The negative electrode plate 112 may provide a negative electrode tab 112a electrically connected to a negative electrode non-coated area, and the positive electrode plate 114 may provide a positive electrode tab 114a electrically connected to a positive electrode non-coated area. In an embodiment, the negative electrode tab 112a and the positive electrode tab 114a may be welded to a negative electrode lead 152 and a positive electrode lead 154 of an external terminal to be electrically connected to the outside. In an embodiment, a tab film 156 for insulating from the pouch 130 may be attached to the negative electrode lead 152 and the positive electrode lead 154.

[0040] In a state where the electrode assembly 110 is accommodated, the pouch 130 may be sealed by contact between seal portions 132 provided on its edge. The sealing may be achieved by using the tab film 156 provided between the seal portions 132. As Figure 1 shown, the tab film 156 attached to each of the negative electrode tab 112a and the positive electrode tab 114a may be defined as a "separated tab film" (this sealing structure may be defined as a separated sealing structure).

[0041] The seal portion 132 of the pouch 130 may be made of a heat-fusible material, and the sealing may be achieved by adhering the heat-fusible layers to each other. Since the heat-fusible material generally has weak adhesion to metal, the tab film 156 in the form of a thin film may be attached to the tab and may be fused to the pouch 130. However, in the separated sealing structure, the tab film 156 is attached and welded to each tab and then heat-fused to the pouch 130, resulting in deterioration of processability and productivity.

[0042] Figure 2 is a perspective view of a secondary battery according to an embodiment; Figure 3 is Figure 2 an enlarged view of area "A" in

[0043] Referring to Figure 2 and Figure 3 , a secondary battery 10 according to an embodiment may include a battery cell 100 and a cover tape 200 coupled to an outer surface of the battery cell 100.

[0044] The basic structure of the battery cell 100 has been described above with reference to Figure 1 . The negative electrode lead 152 and the positive electrode lead 154 of the battery cell 100 may be exposed outside the seal portion 132 of the pouch 130 and may be connected to a lead tab 160, as Figure 2As shown. The battery cell 100 can be connected to an external device, such as a charging / discharging device, via the lead tab 160.

[0045] The cover tape 200 can protect and insulate the pouch 130 of the battery cell 100. The cover tape 200 can be coupled to the outer side of the battery cell 100, such as the outer side of the pouch 130. The cover tape 200 can be coupled to the battery cell 100 so as to cover at least one surface of the battery cell 100.

[0046] For example, the cover tape 200 can be coupled to two side surfaces of the battery cell 100 that are adjacent to the side surface of the battery cell 100 among the side surfaces of the battery cell 100 on which the lead tab 160 is formed. In an embodiment, the cover tape 200 can include wing portions formed on its sides to enhance adhesion to the battery cell 100.

[0047] The adhesive formed on the inner surface of the cover tape for attaching the cover tape may have a risk of being exposed during attachment of the cover tape or use of the secondary battery. If the adhesive is exposed, the assemblability and productivity of the secondary battery may deteriorate, foreign substances may adhere thereto, or the adhesive may enter the external device and may cause defects in the external device.

[0048] However, according to an embodiment, the cover tape 200 for the secondary battery 10 can avoid the above problems by preventing (preventing or substantially preventing) the exposure of the adhesive (e.g., the adhesive located on its edge).

[0049] Here, the structure of the cover tape 200 for the secondary battery 10 according to an embodiment will be described.

[0050] Figure 4 is a plan view of a cover tape of a secondary battery according to an embodiment.

[0051] Referring to Figure 4 the cover tape 200 can include a base region 210 that is a base of its structure (e.g., the entire structure). The base region 210 can be adhered to the lower surface of the battery cell 100 by a first adhesive force.

[0052] The cover tape 200 can further include a first dot region 220, a second dot region 230, and a first fixing region 240. The first dot region 220 is coupled to the base region 210 and thus is disposed on one side of the base region 210 ( Figure 4on the left side in [[]] and having a second adhesive force less than the first adhesive force, the second dot area 230 is formed more outward than the first dot area 220 and has the first adhesive force, the first fixing area 240 is formed on the edge of the second dot area 230 and has a third adhesive force greater than the first adhesive force. The cover tape 200 may further include a termination area 250, which is formed on the edge of the first fixing area 240 and has no adhesive thereon.

[0053] The cover tape 200 may further include a second fixing area 260 and a third dot area 270. The second fixing area 260 is bonded to the base area 210, so as to be disposed on the opposite side ( Figure 4 on the right side in [[]]) of the base area 210 and has the third adhesive force. The third dot area 270 is formed outside the second fixing area and has the second adhesive force. The cover tape 200 may further include a termination area 280, which is formed on the edge of the third dot area 270 and has no adhesive thereon.

[0054] In an embodiment, the base area 210 may be attached to the entire surface of the battery cell 100, such as the lower surface of the battery cell 100. The adhesive formed on the inner surface of the base area 210 may have the first adhesive force, and in an embodiment, the first adhesive force may be 0.20 to 0.50 kgf / 25 mm. In an embodiment, the base area 210 may protect the entire lower surface of the battery cell 100 and may keep the position of the cover tape 200 fixed.

[0055] The first dot area 220 may be bonded to the left side of the base area 210, and the adhesive formed on the inner surface of the first dot area 220 may have a second adhesive force less than the first adhesive force. During the process of manufacturing the adhesive, the dot size of the adhesive may be designed such that its adhesive force corresponds to a second adhesive force less than the first adhesive force. For example, the second adhesive force may be 0.05 to 0.25 kgf / 25 mm. In an embodiment, although the range of the second adhesive force partially overlaps with the range of the first adhesive force, during the manufacturing of the cover tape 200, the second adhesive force may be less than the first adhesive force. For example, the first dot area 220 may be attached to the battery cell 100 with an adhesive force smaller than the adhesive force used for attaching the base area 210 to the battery cell 100.

[0056] The second dot area 230 may be formed more outward than the first dot area 220 and may have the first adhesive force. The second dot area 230 may be formed to cover the side surface of the battery cell 100 and may be bent so as to also cover a part of the upper surface of the battery cell 100. For example, the second dot area 230 may be attached to the outer surface of the battery cell 100 with an adhesive force greater than the adhesive force used for attaching the first dot area 220 to the battery cell 100.

[0057] The first fixing region 240 may be formed on the edge of the second dot region 230 and may have a third adhesive force. For example, the third adhesive force may be 1.10 to 1.40 kgf / 25 mm. Since the first fixing region 240 is attached to the battery cell 100 at the outermost edge of the cover tape 200 with the maximum adhesive force, the bonding shape and position of the cover tape 200 may be kept fixed. In an embodiment, the first fixing region 240 may be provided with wings 241 at its ends. The wings 241 may be attached to the side surface of the battery cell 100 opposite to the side surface of the battery cell 100 on which the lead tab 160 is formed.

[0058] The termination region 250 may be formed on the edge of the first fixing region 240 and may have no adhesive thereon. Since the termination region 250 has no adhesive thereon, even if the adhesive on the first fixing region 240 leaks from it due to the pressure applied to it during the attachment process, the termination region 250 can receive the adhesive. Therefore, the adhesive can be prevented or substantially prevented from being exposed to the outside of the cover tape 200.

[0059] The second fixing region 260 may be bonded to the right side of the base region 210, and the adhesive formed on the inner surface of the second fixing region 260 may have a third adhesive force. The second fixing region 260 may be stably attached to the right surface of the battery cell 100 using an adhesive having a high adhesive force. In an embodiment, the second fixing region 260 is attached to the entire right surface of the battery cell 100 in the longitudinal direction of the battery cell 100, so that the attachment area can be large. The second fixing region 260 may be firmly attached to the battery cell 100 due to its adhesive having a relatively strong third adhesive force. In an embodiment, the second fixing region 260 may be provided with wings 261 at its ends. The wings 261 may be attached to the side surface of the battery cell 100 opposite to the side surface of the battery cell 100 on which the lead tab 160 is formed.

[0060] The third dot region 270 may be formed outside the second fixing region, and its adhesive may have a second adhesive force. During the process of manufacturing the adhesive, the dot size of the adhesive may be designed such that its adhesive force corresponds to a second adhesive force less than the first adhesive force. In an embodiment, the third dot region 270 is formed to extend along the second fixing region 260 in the longitudinal direction of the battery cell 100, and even if the adhesive of the second fixing region 260 moves, the adhesive can be received within the second fixing region 260 without being exposed. In an embodiment, the adhesive of the third dot region 270 has a second adhesive force less than the first adhesive force, so that the exposure of the adhesive of the third dot region 270 to the outside during the manufacturing process can be reduced.

[0061] In an embodiment, a termination zone 280 without an adhesive thereon may be further provided on the edge of the third dot zone 270. In an embodiment, the termination zone 280 has no adhesive on the inner surface of the base material of the tape. Even if the adhesive leaking from the third dot zone 270 moves during the manufacturing process, the adhesive can be received within the termination zone 280. Thus, exposure of the adhesive to the outside can be prevented or substantially prevented.

[0062] Although the termination zones 250 and 280 have been described as non - adhesive zones without an adhesive thereon, in one or more embodiments, the termination zones 250 and 280 can be used as dams against the adhesive by increasing the thickness of the base material of the termination zones 250 and 280. In an embodiment, the termination zones 250 and 280 can prevent or substantially prevent the adhesive from the first fixing zone 240 and the third dot zone 270 from leaking therefrom, and thus can prevent or substantially prevent the exposure of the adhesive.

[0063] Here, the configuration in which the cover tape is bonded to the battery cell in the structure of the secondary battery according to the embodiment will be described.

[0064] Figure 5 is a side view when observed in the direction "B" as shown in Figure 2 The structure shown in

[0065] Figure 5 is the structure observed in the direction "B" in the state where the cover tape 200 is attached to the battery cell 100. In an embodiment, as described above, the base zone 210 can be attached to the entire lower surface of the battery cell 100.

[0066] The first dot zone 220 and the first fixing zone 240 can cover the side surface of the battery cell 100 ( Figure 4 the left surface in Figure 5 ), and the first dot zone 220 can also cover a part of the upper surface of the battery cell 100. The wing portion 241 of the first fixing zone 240 can be bent to be attached to the side surface of the battery cell 100 opposite to the side surface on which the lead tab is formed on the battery cell 100 (as seen in

[0067] The second dot zone 230 can extend from the first dot zone 220 to be attached to the upper surface of the battery cell 100, and the termination zone 250 provided at the end of the second dot zone 230 can prevent or substantially prevent the exposure of the adhesive. Figure 4 The second fixing zone 260 can cover the other side surface of the battery cell 100 ( Figure 5(the side surface as seen in). The third point area 270 may further cover a part of the upper surface of the battery cell 100. The termination areas 280 provided at the ends of the third point area 270 may prevent or substantially prevent the exposure of the adhesive.

[0068] As described above, in the secondary battery 10 according to the embodiment, the cover tape 200 may be bonded to the lower surface, side surface, and a part of the upper surface of the battery cell 100, and the second point area 220 and the third point area 270 of the cover tape 200 covering the upper surface of the battery cell may have a relatively low adhesive force, thereby preventing or substantially preventing the adhesive from being exposed from the upper surface of the battery cell 100.

[0069] In the embodiment, the termination areas 250 and 280 to which no adhesive is applied are formed at the ends of the second point area 230 and the third point area 270, and may prevent or substantially prevent the adhesives of the second point area 230 and the third point area 270 from being exposed.

[0070] In one or more embodiments, the termination areas 250 and 280 may be formed in the form of dams by increasing the thickness of the base material of the tape, thereby preventing or substantially preventing the adhesives of the second point area 230 and the third point area 270 from moving and thus being exposed. In the embodiment, the termination areas 250 and 280 may be configured to be in direct contact with the upper surface of the battery cell 100 (i.e., the upper surface of the pouch 130), thereby preventing or substantially preventing the exposure of the adhesive.

[0071] As is apparent from the above description, the embodiment may provide a secondary battery configured such that the cover tape is bonded to the lower surface, side surface, and a part of the upper surface of the battery cell, such that the second point area and the third point area of the cover tape covering the upper surface of the battery cell have a relatively low adhesive force, thereby preventing or substantially preventing the adhesive from being exposed from the upper surface of the battery cell.

[0072] In some embodiments, termination areas to which no adhesive is applied may be formed at the ends of the second point area and the ends of the third point area, and thus the adhesives of the second point area and the third point area may be prevented or substantially prevented from being exposed.

[0073] In some embodiments, the termination areas may be formed in the form of dams by increasing the thickness of the base material of the tape, thereby preventing or substantially preventing the adhesives of the second point area and the third point area from moving and thus being exposed.

[0074] However, the aspects and effects of the present disclosure are not limited to the above, and based on the above description of some exemplary embodiments, other technical aspects and effects not mentioned will be apparent to those skilled in the art.

[0075] Although the present disclosure has been described above in connection with a limited number of exemplary embodiments and the accompanying drawings, the present disclosure is not limited thereto, and it should be understood that those skilled in the art can make various changes and modifications within the spirit and scope of the present disclosure and the appended claims and their equivalents.

[0076] This application claims the benefit of priority and the benefit of the Korean Patent Application No. 10-2023-0192791, filed on December 27, 2023, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference.

Claims

1. A secondary battery comprising: Electrode assembly; a bag for accommodating the electrode assembly; as well as a cover tape attached to the bag so as to at least partially cover at least two surfaces of the bag, wherein the cover tape comprises a fixed area attached to the first surface of the bag, a dot area attached to the second surface of the bag, and adhesive on the fixed area and the dot area, and The adhesives described therein have different adhesive strengths.

2. The secondary battery according to claim 1, wherein the fixing area of ​​the cover tape covers a side surface of the bag, and The point areas of the cover tape cover at least a portion of the upper surface of the bag. 3 . The secondary battery according to claim 2 , wherein the adhesive on the dot region has an adhesive force smaller than an adhesive force of the adhesive on the fixing region. 4 . The secondary battery according to claim 1 , wherein the cover tape comprises a base region attached to a lower surface of the pouch and having a first adhesive force.

5. The secondary battery according to claim 4, wherein the cover tape comprises: a first spot region extending from a side surface of the base region and having a second adhesive force; a second spot area on an edge of a portion of the first spot area and having the first adhesive force; as well as The first fixing area is on the edge of the second point area and has a third adhesive force. The secondary battery according to claim 5 , wherein the second adhesive force is smaller than the first adhesive force. The secondary battery according to claim 5 , wherein the third adhesive force is greater than the first adhesive force. 8 . The secondary battery according to claim 5 , wherein the first adhesive force is 0.20 to 0.50 kgf / 25 mm. 9 . The secondary battery according to claim 5 , wherein the second adhesive force is 0.05 to 0.25 kgf / 25 mm. 10 . The secondary battery according to claim 5 , wherein the third adhesive force is 1.10 to 1.40 kgf / 25 mm. 11 . The secondary battery according to claim 5 , wherein the cover tape further comprises a termination area which is at an end of the first fixing area or the third spot area and to which no adhesive is applied. 12 . The secondary battery according to claim 11 , wherein the termination region is on an outermost edge of the first fixing region or the third dot region. 13 . The secondary battery according to claim 11 , wherein the termination region has a thickness different from a thickness of a base material of the cover tape. 14 . The secondary battery according to claim 11 , wherein the termination area is thicker than a base material of the cover tape and contacts an upper surface of the pouch.

15. The secondary battery according to claim 4, wherein the cover tape further comprises: a second fixing region extending from an opposite side surface of the base region and having a third adhesive force; as well as The third spot area extends along the outer side of the second fixing area and has a second adhesive force.

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