Secondary battery

Abstract

The secondary battery includes: an electrode assembly including first electrode plates and second electrode plates alternately stacked with separators therebetween; first electrode tabs overlapping each other at the same position and protruding outward, the first electrode tabs being uncoated portions of the first electrode plate; and a fixing band adhered to outer surfaces of the separator and the first electrode tab at each of opposite long side surfaces; a first current collector portion coupled to the first electrode tab of the electrode assembly; and a case accommodating the electrode assembly and the first current collector portion.

Description

[0001] This application is a divisional application of an application with a filing date of March 10, 2020, application number 202010160663.5, and invention name “Secondary Battery”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0037113 filed in the Korean Intellectual Property Office on March 29, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0004] Aspects of embodiments of the present disclosure relate to a secondary battery. Background Art

[0005] Unlike primary batteries that cannot be charged, secondary batteries can be charged and discharged. Low-capacity secondary batteries packaged in a package including a single battery cell can be used as a power source for various portable small electronic devices (e.g., cellular phones or portable cameras), while high-capacity secondary batteries with dozens of battery packs connected to each other are widely used as a motor drive power source, such as in hybrid vehicles, electric vehicles, etc.

[0006] A secondary battery can be manufactured by accommodating an electrode assembly (having a separator between a positive electrode plate and a negative electrode plate) and an electrolyte in a housing and then installing a cover plate on the housing. Here, the electrode assembly can be represented by a wound type or a stacked type, for example. Such an electrode assembly can have an uncoated region tab protruding upward or laterally, and a current collector member connected to the uncoated region tab.

[0007] The above information disclosed in this Background section is provided for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0008] According to one aspect of an embodiment of the present disclosure, there is provided a secondary battery in which misalignment of electrode plates due to external force can be prevented or substantially prevented as a fixing tape fixes separators and electrode tabs located at the outermost sides of an electrode assembly.

[0009] The above and other aspects and features of the present disclosure will be described in or will be apparent from the following description of some example embodiments of the present disclosure.

[0010] According to one or more embodiments of the present disclosure, a secondary battery includes: an electrode assembly, including a first electrode plate and a second electrode plate, the first electrode plates and the second electrode plates being alternately stacked with a separator therebetween; a plurality of first electrode tabs overlapping each other at the same position and protruding outward, the first electrode tabs being uncoated portions of the first electrode plates; and a fixing tape adhered to outer surfaces of the separator and the first electrode tabs at each of opposite long side surfaces of the electrode assembly; a first current collector portion connected to the first electrode tab of the electrode assembly; and a shell accommodating the electrode assembly and the first current collector portion.

[0011] The first electrode tab may protrude outward from one of opposite short side surfaces of the electrode assembly and may be gathered to be then welded to the first current collector portion.

[0012] The fixing tape may include a first region adhered to an outer surface of the separator and a second region adhered to an outer surface of the first electrode tab.

[0013] The second region of the fixing tape may be bent toward one short side surface of the electrode assembly to cover a portion of the one short side surface.

[0014] The electrode assembly may further include a plurality of second electrode tabs which are uncoated portions of the second electrode plate and protrude outward from the other of the opposite short side surfaces of the electrode assembly.

[0015] The fixing tape may be adhered to an outer surface of the separator and an outer surface of the second electrode tab.

[0016] The separator may extend perpendicularly to directions in which the first electrode tab and the second electrode tab, respectively located in the first electrode plate and the second electrode plate, protrude, and may be bent in a Z-shaped configuration.

[0017] The fixing tape may include a first region adhered to an outer surface of the separator and a second region adhered to an outer surface of the second electrode tab.

[0018] The fixing tape may include: two tapes adhered to a first side end and a first electrode tab on one long side surface of the electrode assembly and a second side end and a second electrode tab on one long side surface of the electrode assembly; and two tapes adhered to a first side end and a first electrode tab on the other long side surface of the electrode assembly and a second side end and a second electrode tab on the other long side surface of the electrode assembly.

[0019] The fixing tape may contain polyimide (PI), polypropylene (PP) or polyethylene terephthalate (PET).

[0020] As described above, according to one aspect of an embodiment of the present disclosure, in a secondary battery, misalignment of the electrode plates due to external force applied to the electrode plates can be prevented or substantially prevented by fixing and adhering a fixing tape to the outermost separators and electrode tabs of the electrode assembly.

[0021] Further, according to one aspect of an embodiment of the present disclosure, a secondary battery is provided, comprising a fixing tape fixedly adhered to the outermost separator and the first electrode tab and the outermost separator and the second electrode tab located at the electrode assembly, thereby preventing or substantially preventing misalignment of the electrode plates, which may occur when a plurality of electrode tabs each protruding to opposite sides of the electrode assembly are brought together. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1A and Figure 1B are a perspective view and a cross-sectional view of a secondary battery according to an embodiment of the present disclosure.

[0023] Figure 2A , Figure 2B and Figure 2C yes Figure 1A and Figure 1B An exploded perspective view, a perspective view, and a partial perspective view of an electrode assembly of a secondary battery are shown.

[0024] Figure 3A and Figure 3B is an example Figure 1A and Figure 1B An exploded perspective view and an assembled perspective view of a current collector portion and an electrode assembly in a secondary battery are shown. DETAILED DESCRIPTION

[0025] Here, some example embodiments of the present disclosure will be described in further detail. However, the subject matter of the present disclosure can be implemented in many different forms and should not be interpreted as being limited to the example (or exemplary) embodiments set forth herein. On the contrary, these example embodiments are provided so that the present disclosure will be thorough and complete, and will convey various aspects and features of the present disclosure to those skilled in the art.

[0026] In addition, in the accompanying drawings, for the sake of brevity and clarity, the size or thickness of various parts may be exaggerated. Throughout the text, the same reference numerals indicate the same elements. As used herein, the term "and / or" includes any and all combinations of one or more related listed items. In addition, it should be understood that when element A is referred to as "connected to" element B, element A can be directly connected to element B, or there can be one or more intermediate elements C between them so that element A and element B are indirectly connected to each other.

[0027] It should also be understood that the terms “include” and / or “comprises”, when used in this specification, specify the presence of the described features, quantities, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components and / or groups thereof.

[0028] It should be understood that although the terms "first", "second", etc. may be used herein to describe various components, elements, regions, layers and / or sections, these components, elements, regions, layers and / or sections should not be limited by these terms. These terms are used to distinguish one component, element, region, layer and / or section from another component, element, region, layer and / or section. Thus, for example, the first component, first element, first region, first layer and / or first section discussed below may be referred to as the second component, second element, second region, second layer and / or second section without departing from the teachings of the present disclosure.

[0029] For ease of description, spatially relative terms such as "below," "beneath," "below," "above," "on," etc. may be used herein to describe the relationship of one element or feature to another element or feature (or other elements or features) as shown in the figures. It should be understood that in addition to the orientations depicted in the drawings, spatially relative terms are intended to include different orientations of the device in use or operation. For example, if the device in the drawings is turned over, elements described as being "below" or "beneath" other elements or features will then be oriented as being "on" or "above" the other elements or features. Therefore, the example term "below" can include both above and below orientations.

[0030] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. It should be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and should not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0031] Reference Figure 1A and Figure 1B , illustrating a perspective view and a cross-sectional view of a secondary battery according to an embodiment of the present disclosure. That is, Figure 1B It is along Figure 1A A cross-sectional view taken along line 1B-1B of FIG. Figure 3A and Figure 3B , an example shows Figure 1A and Figure 1B An exploded perspective view and an assembled perspective view of a current collector portion and an electrode assembly in a secondary battery are shown.

[0032] like Figure 1A and Figure 1B As shown, a secondary battery 100 according to an embodiment of the present disclosure includes a stacked electrode assembly 110, a first collector portion 120 electrically connected to one side of the electrode assembly 110 (for example, electrically connected to a first electrode tab 114), a first terminal portion 130 electrically connected to the first collector portion 120, a second collector portion 140 electrically connected to the other side of the electrode assembly 110 (for example, electrically connected to a second electrode tab 115), a second terminal portion 150 electrically connected to the second collector portion 140, a shell 160 accommodating the electrode assembly 110, the first collector portion 120 and the second collector portion 140, and a cover assembly 170 connected to an opening of the shell 160.

[0033] The secondary battery 100 according to an embodiment of the present disclosure will be described with respect to a prismatic lithium ion secondary battery by way of example, but the present disclosure is not limited thereto and may be applied to any of various types of batteries including, for example, a lithium polymer battery.

[0034] The electrode assembly 110 may include a first electrode plate 111, a second electrode plate 112, a separator 113 located between the first electrode plate 111 and the second electrode plate 112, and a fixing tape 116. FIG. 2A to FIG. 2C , example Figure 1A and Figure 1B The exploded perspective view, perspective view and partial perspective view of the electrode assembly of the secondary battery shown in FIG. FIG. 2A to FIG. 2C The configuration of the electrode assembly 110 is described.

[0035] The electrode assembly 110 includes a first electrode plate 111, a second electrode plate 112, and a separator 113 located between the first electrode plate 111 and the second electrode plate 112. In one embodiment, the electrode assembly 110 may include a stack of a plurality of first electrode plates 111 and a plurality of second electrode plates 112. Figure 2A As shown, the separator 113 may have a plate shape that is bent in a Z-shaped configuration so as to be located between each of the first electrode plates 111 and each of the second electrode plates 112 to be then stacked. In one embodiment, in order to prevent or substantially prevent a short circuit between the first electrode plate 111 and the second electrode plate 112, the size of the separator 113 may be greater than the size of the first electrode plate 111 and the second electrode plate 112. In addition, the separator 113 may be located at one or more outermost sides of the electrode assembly 110, that is, at the opposite long side surfaces 110a of the stacked electrode assembly 110. In addition, the first electrode tab 114 and the second electrode tab 115 may protrude outward from the opposite short side surfaces 110b of the electrode assembly 110.

[0036] In one embodiment, the first electrode plate 111 may be used as a positive electrode, and the second electrode plate 112 may be used as a negative electrode. In another embodiment, the first electrode plate 111 may be used as a negative electrode, and the second electrode plate 112 may be used as a positive electrode. For convenience, the following description will be made by way of example regarding a case where the first electrode plate 111 is used as a positive electrode and the second electrode plate 112 is used as a negative electrode.

[0037] The first electrode plate 111 may include: a first electrode current collector 111a made of a metal foil including, for example, aluminum or an aluminum alloy; a first electrode active material 111b coated on the first electrode current collector 111a, such as a transition metal oxide; and a first electrode tab 114 (e.g., a first uncoated portion), the first electrode tab 114 being a first uncoated region on which the first electrode active material 111b is not coated. The first electrode tab 114 becomes a path for current to flow between the first electrode plate 111 and the first collector portion 120. In one embodiment, the first electrode tab 114 is pre-formed by being cut to protrude to one side of the first electrode plate 111 when manufacturing the first electrode plate 111, thereby being integrally formed with the first electrode current collector 111a. A plurality of first electrode plates 111 may be stacked so that the first electrode tabs 114 overlap each other at the same position. In one embodiment, a plurality of first electrode tabs 114 may be substantially gathered at the center of one short side surface 110b of the electrode assembly 110 to then be coupled to each other during welding and attached to the first collector portion 120. In some examples, a plurality of first electrode tabs 114 may be gathered to be temporarily welded to each other, and then the first current collector portion 120 may be welded and coupled to the temporarily welded first electrode tabs 114 .

[0038] like Figure 2B As shown, the first electrode tab 114 may protrude outward from one short side surface of the electrode assembly 110 and extend a certain length (e.g., a predetermined length). In one embodiment, when the first electrode tabs 114 are welded and coupled to each other, the coupled first electrode tabs 114 may be bent substantially in an L-shaped configuration, such as Figure 2C With this configuration, the first electrode tab 114 may be connected to the first current collector portion 120, which will be described below. In some examples, the first electrode tab 114 of the electrode assembly 110 is initially flat, such as Figure 2B However, after being welded to the first current collector portion 120, the first electrode tab 114 may be bent substantially in an L-shaped configuration.

[0039] The second electrode plate 112 may include: a second electrode current collector 112a made of a metal foil including, for example, copper or nickel; a second electrode active material 112b coated on the second electrode current collector 112a, such as a transition metal oxide; and a second electrode terminal 115 (e.g., a second uncoated portion), the second electrode terminal 115 being a second uncoated region on which the second electrode active material 112b is not coated. The second electrode terminal 115 becomes a path for current to flow between the second electrode plate 112 and the second collector portion 140. In one embodiment, the second electrode terminal 115 is pre-formed by being cut to protrude to one side of the second electrode plate 112 when manufacturing the second electrode plate 112, so as to be formed integrally with the second electrode current collector 112a. A plurality of second electrode plates 112 may be stacked so that the second electrode terminal 115 overlaps each other at the same position. In one embodiment, a plurality of second electrode plates 112 may be stacked so that the second electrode terminal 115 is positioned opposite to the first electrode terminal 114. In one embodiment, a plurality of second electrode tabs 115 may be substantially gathered at the center of the other short side surface 110b of the electrode assembly 110 to then be coupled to each other during welding to be attached to the second current collector portion 140. In some examples, a plurality of second electrode tabs 115 may be temporarily welded to each other, and then the second current collector portion 140 may be welded and coupled to the temporarily welded second electrode tabs 115.

[0040] like Figure 2B As shown, the second electrode tab 115 may protrude outward from the other short side surface 110b of the electrode assembly 110 and extend a certain length (e.g., a predetermined length). In one embodiment, when the second electrode tabs 115 are welded and coupled to each other, the coupled second electrode tabs 115 may be bent substantially in an L-shaped configuration, such as Figure 2C As shown. With this configuration, the second electrode tab 115 can be connected to the second collector portion 140, which will be described below. In some examples, the second electrode tab 115 of the electrode assembly 110 is initially flat, such as Figure 2B However, after being welded to the second current collector portion 140, the second electrode tab 115 may be bent substantially in an L-shaped configuration.

[0041] The separator 113 is located between the first electrode plate 111 and the second electrode plate 112 to prevent or substantially prevent electrical short circuits and allow lithium ions to move. In one embodiment, the separator 113 may be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene. In one embodiment, the separator 113 may extend perpendicular to the direction in which the first electrode tab 114 and the second electrode tab 115 protrude, and may be bent in a Z-shaped configuration to then be positioned between the first electrode plate 111 and the second electrode plate 112.

[0042] The fixing tape 116 may be adhered to the separator 113 and the first electrode tab 114 located at the outermost side of the electrode assembly 110 , and the separator 113 and the second electrode tab 115 located at the outermost side of the electrode assembly 110 .

[0043] The fixing tape 116 may be located at opposite ends of each of the long side surfaces 110a of the electrode assembly 110. For example, the fixing tape 116 may be adhered to a first side end and a first electrode tab 114 of one long side surface 110a of the electrode assembly 110, and a second side end and a second electrode tab 115 of the one long side surface 110a. In addition, the fixing tape 116 may be adhered to a first side end and a first electrode tab 114 of the other long side surface 110a of the electrode assembly 110, and a second side end and a second electrode tab 115 of the other long side surface 110a. Therefore, in one embodiment, one single electrode assembly 110 may include four fixing tapes 116, wherein two fixing tapes 116 are adhered to each of the opposite long side surfaces 110a.

[0044] In one embodiment, each of the four fixing tapes 116 has a first region 116a adhered to the separator 113 and a second region 116b adhered to any one of the first electrode tab 114 and the second electrode tab 115. In one embodiment, the fixing tape 116 may be a film-type tape having an adhesive layer on one surface thereof. In one embodiment, the fixing tape 116 may include a high heat-resistant material to prevent or substantially prevent damage when the first collector portion 120 and the first electrode tab 114 are welded to each other or when the second collector portion 140 and the second electrode tab 115 are welded to each other. For example, the fixing tape 116 may include polyimide (PI), polypropylene (PP), or polyethylene terephthalate (PET).

[0045] For convenience, in the following description, the first electrode tab 114 and the second electrode tab 115 may be referred to as an electrode tab 114 and an electrode tab 115 , respectively.

[0046] In one embodiment, each of the four fixing tapes 116 may be adhered such that the first region 116a is adhered to the opposite ends of the separator 113 located on the opposite long side surfaces 110a of the stacked electrode assembly 110, and the second region 116b is adhered to the outer surfaces 114a and 115a of the outermost electrode tabs 114 and 115 located closest to the outermost separator 113 among the electrode tabs 114 and 115 protruding at the short side surfaces 110b of the electrode assembly 110. Here, the outer surface 114a of the first electrode tab 114 and the outer surface 115a of the second electrode tab 115 refer to the outwardly exposed surfaces of the corresponding electrode tabs that do not face other electrode tabs 114 and 115 among the plurality of electrode tabs 114 and 115 of the stacked electrode assembly 110.

[0047] The fixing tape 116 may fix the separator 113 and the electrode tabs 114 and 115 located at the outermost side of the electrode assembly 110 to each other. The fixing tape 116 may prevent or substantially prevent the first electrode plate 111 from being misaligned with the second electrode plate 112 when a plurality of first electrode tabs 114 and a plurality of second electrode tabs 115, each protruding from opposite short side surfaces of the electrode assembly 110, are collected. In one embodiment, the plurality of first electrode tabs 114 are collected to be welded to the first collector portion 120 and then positioned substantially at the center of one short side surface 110b of the electrode assembly 110. In one embodiment, the plurality of second electrode tabs 115 may be collected to be welded to the second collector portion 140 and then positioned substantially at the center of the other short side surface 110b of the electrode assembly 110.

[0048] When the first electrode tab 114 and the second electrode tab 115 are respectively collected, the second region 116 b of the fixing tape 116 may be bent toward the short side surface 110 b of the electrode assembly 110 to cover portions of the opposite short side surface 110 b .

[0049] The electrode assembly 110 is accommodated in the housing 160 together with, for example but not limited to, an electrolyte. In one embodiment, the electrolyte may include an organic solvent (e.g., ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), or dimethyl carbonate (DMC)) and a lithium salt (e.g., LiPF 6 or LiBF 4 ). In addition, the electrolyte may be in a liquid, solid or gel state.

[0050] In one embodiment, the first collector portion 120 includes a first sub-collector portion 121 electrically and mechanically connected to the first electrode tab 114, and a first main collector portion 122 electrically and mechanically connected to the first sub-collector portion 121. In one embodiment, after being coupled to the first terminal portion 130 coupled to the cap assembly 170, the first collector portion 120 may be coupled to the first electrode tab 114 of the electrode assembly 110. Figure 3A , illustrating an exploded perspective view of the electrode assembly 110 before being coupled to the first current collector portion 120. Figure 3B , illustrating an assembled perspective view of the electrode assembly 110 coupled to the first current collector portion 120. Now, reference will be made to Figure 3A and Figure 3B The configuration of the first current collector portion 120 and an assembling operation between the first current collector portion 120 and the electrode assembly 110 are described.

[0051] In one embodiment, the first sub-collector portion 121 includes a first tab connection portion 121a electrically and mechanically connected to the first electrode tab 114, and a first collector connection portion 121b electrically and mechanically connected to the first main collector portion 122. In one embodiment, the first sub-collector portion 121 may be formed as a single plate extending in a vertical direction, and may have a portion bent to be parallel to the vertical direction. The first tab connection portion 121a may be located between the first electrode tab 114 and the first main collector portion 122, and the first collector connection portion 121b may be located between the first electrode tab 114 and the side surface of the electrode assembly 110. In one embodiment, the first sub-collector portion 121 may be a metal single plate.

[0052] In one embodiment, in a state where the first sub-current collector portion 121 is bent in an L-shaped configuration, the first current collector connecting portion 121b disposed on one side may be first welded to the first main current collector portion 122, and then the first tab connecting portion 121a disposed on the other side may be welded to the first electrode tab 114. After the first sub-current collector portion 121 is welded to the first electrode tab 114 in a state where one surface of the first sub-current collector portion 121 is in contact with one surface of the first electrode tab 114, the first sub-current collector portion 121 may be bent together with the first electrode tab 114 to be substantially parallel to the surface of the first current collector portion 120.

[0053] The first tab connection portion 121a may be welded to the collected plurality of first electrode tabs 114 at once. Here, the first electrode tabs 114 welded to the first tab connection portion 121a may be electrically connected to each other while being in close contact with each other, thereby reducing the overall thickness of the first electrode tab 114.

[0054] In one embodiment, the first main current collector portion 122 includes a first electrode connecting portion 122a electrically and mechanically connected to the first sub-current collector portion 121, and a first terminal connecting portion 122b bent and extended from the top end of the first electrode connecting portion 122a and electrically and mechanically connected to the first terminal portion 130.

[0055] The first electrode connection portion 122a contacts and is coupled to the first sub-current collector portion 121 to be then electrically connected to the first electrode tab 114 of the electrode assembly 110. In one embodiment, the first electrode connection portion 122a is welded to the first sub-current collector portion 121 and is configured to extend in a vertical direction. The first electrode connection portion 122a may be coupled to the first sub-current collector portion 121 by welding.

[0056] In one embodiment, the first terminal connection portion 122b is formed as a plate extending horizontally to be parallel to the cap plate 171 of the cap assembly 170, and is coupled to the first terminal portion 130. In one embodiment, the first terminal connection portion 122b may be welded to the first terminal portion 130, and may be located between the cap plate 171 of the cap assembly 170 to be described later and the electrode assembly 110. In one embodiment, the first terminal connection portion 122b may be bent from the top end of the first electrode connection portion 122a to extend perpendicularly thereto.

[0057] In one embodiment, the first sub-current collector portion 121, the first main current collector portion 122 and the first electrode tab 114 may be made of the same material. In one embodiment, the first electrode tab 114 is made of aluminum, and the first current collector portion 120 is also made of an aluminum-based material.

[0058] In one embodiment, the first main current collector portion 122 is coupled to the first sub-current collector portion 121 by welding to provide the first current collector portion 120. In addition, the first current collector portion 120 consisting of the first sub-current collector portion 121 and the first main current collector portion 122 may be welded and coupled to the first terminal portion 130 coupled to the cap assembly 170. The first tab connection portion 121a of the first current collector portion 120 may then be welded and coupled to the collected plurality of first electrode tabs 114. In one embodiment, the first tab connection portion 121a is welded to the first electrode tab 114 by ultrasonic welding with pressure (e.g., a predetermined pressure) applied thereto.

[0059] However, those skilled in the art will appreciate that, for better understanding of the example embodiments of the present disclosure, the first collector portion 120 is described herein by way of example, but the first collector portion 120 may be implemented in any of a variety of shapes and structures.

[0060] The first terminal portion 130 is electrically connected to the first electrode tab 114 of the electrode assembly 110 through the first collector portion 120. In one embodiment, the first terminal portion 130 may include a first terminal column 131 passing through the cap plate 171 of the cap assembly 170, and is configured such that the first electrode connection portion 122a of the first collector portion 120 is electrically connected to the first terminal column 131 within the housing 160. In addition, the first electrode tab 114 of the electrode assembly 110 is electrically connected to the first collector portion 120. In one embodiment, the first terminal portion 130 is positioned on the cap plate 171, and may include: a first terminal plate 132 (e.g., made of aluminum) coupled to the first terminal column 131; a first terminal upper insulating member 133 installed between the first terminal plate 132 and the cap plate 171; a first terminal sealing gasket 134 located between the first terminal column 131 and the cap plate 171; and a first terminal lower insulating member 135 installed between the first collector portion 120 coupled to the first terminal column 131 and the cap plate 171.

[0061] In one embodiment, the first terminal upper insulating member 133 may be replaced by a high resistance conductor. In this case, the cap plate 171 and the housing 160 may have the same polarity as the first terminal portion 130. For example, the housing 160 and the cap plate 171 of the secondary battery 100 may be positively charged.

[0062] However, those skilled in the art will appreciate that, for better understanding of the example embodiments of the present disclosure, the first terminal portion 130 is described herein by way of example, but the first terminal portion 130 may be implemented in any of a variety of shapes and structures.

[0063] In one embodiment, the second current collector portion 140 includes a second sub-current collector portion 141 electrically and mechanically connected to the second electrode tab 115 , and a second main current collector portion 142 electrically and mechanically connected to the second sub-current collector portion 141 .

[0064] In one embodiment, after being coupled to the second terminal portion 150 coupled to the cap assembly 170, the second current collector portion 140 may be coupled to the second electrode tab 115 of the electrode assembly 110. Figure 3A , illustrating an exploded perspective view of the electrode assembly 110 before being coupled to the second current collector portion 140. Figure 3B , illustrating an assembled perspective view of the electrode assembly 110 coupled to the second current collector portion 140. Reference will now be made to Figure 3A and Figure 3B The configuration of the second current collector portion 140 and an assembling operation between the second current collector portion 140 and the electrode assembly 110 are described.

[0065] In one embodiment, the second sub-collector portion 141 may include a second tab connection portion 141a electrically and mechanically connected to the second electrode tab 115, and a second collector connection portion 141b electrically and mechanically connected to the second main collector portion 142. In one embodiment, the second sub-collector portion 141 may be formed as a single plate extending in a vertical direction, and may have a portion bent to be parallel to the vertical direction. The second tab connection portion 141a may be located between the second electrode tab 115 and the second collector portion 140, and the second collector connection portion 141b may be located between the second electrode tab 115 and the side surface of the electrode assembly 110. In one embodiment, the second sub-collector portion 141 may be a metal single plate.

[0066] In one embodiment, in a state where the second sub-current collector portion 141 is bent in an L-shaped configuration, the second current collector connecting portion 141b disposed on one side may be first welded to the second main current collector portion 142, and then the second tab connecting portion 141a disposed on the other side may be welded to the second electrode tab 115. After being welded to the second electrode tab 115, the second sub-current collector portion 141 may be bent together with the second electrode tab 115 to be substantially parallel to the surface of the second current collector portion 140.

[0067] In one embodiment, the second tab connection portion 141a may be welded to the collected plurality of second electrode tabs 115 at one time. Here, the second electrode tabs 115 welded to the second tab connection portion 141a may be electrically connected to each other while being in close contact with each other, thereby reducing the overall thickness of the second electrode tab 115.

[0068] The second main current collector portion 142 includes a second electrode connecting portion 142 a electrically and mechanically connected to the second sub-current collector portion 141 , and a second terminal connecting portion 142 b bent and extended from a top end of the second electrode connecting portion 142 a and electrically and mechanically connected to the second terminal portion 150 .

[0069] The second electrode connection portion 142a contacts and is coupled to the second sub-current collector portion 141 to be then electrically connected to the second electrode tab 115 of the electrode assembly 110. The second electrode connection portion 142a is welded to the second sub-current collector portion 141 and is configured to stand upright in a vertical direction. The second electrode connection portion 142a may be coupled to the second sub-current collector portion 141 by welding.

[0070] In one embodiment, the second terminal connection portion 142b is formed as a plate extending horizontally to be parallel to the cap plate 171, and is coupled to the second terminal portion 150. In one embodiment, the second terminal connection portion 142b may be welded to the second terminal portion 150, and may be located between the cap plate 171 of the cap assembly 170 to be described later and the electrode assembly 110. In one embodiment, the second terminal connection portion 142b may be bent from the top end of the second electrode connection portion 142a to extend perpendicularly thereto.

[0071] In one embodiment, the second sub-current collector portion 141, the second main current collector portion 142 and the second electrode tab 115 may be made of the same material. In one embodiment, the second electrode tab 115 is made of a copper-based material, and the second current collector portion 140 is also made of a copper-based material.

[0072] In one embodiment, the second main current collector portion 142 is coupled to the second sub-current collector portion 141 by welding to provide the second current collector portion 140. In one embodiment, the second current collector portion 140 consisting of the second sub-current collector portion 141 and the second main current collector portion 142 may be welded and coupled to the second terminal portion 150 coupled to the cap assembly 170. The second tab connection portion 141a of the second current collector portion 140 may then be welded and coupled to the assembled plurality of second electrode tabs 115.

[0073] However, those skilled in the art will appreciate that the second collector portion 140 is described herein by way of example for better understanding of the example embodiments of the present disclosure, but the second collector portion 140 may be implemented in any of various shapes and structures.

[0074] The second terminal portion 150 is electrically connected to the second electrode tab 115 of the electrode assembly 110 through the second collector portion 140. In one embodiment, the second terminal portion 150 may include a second terminal column 151 passing through the cap plate 171 of the cap assembly 170, and is configured such that the second electrode connection portion 142a of the second collector portion 140 is electrically connected to the second terminal column 151 within the housing 160. In addition, the second electrode tab 115 of the electrode assembly 110 is electrically connected to the second collector portion 140. In one embodiment, the second terminal portion 150 is positioned on the cap plate 171, and may include: a second terminal plate 152 (e.g., made of aluminum) coupled to the second terminal column 151; a second terminal upper insulating member 153 installed between the second terminal plate 152 and the cap plate 171; a second terminal sealing gasket 154 located between the second terminal column 151 and the cap plate 171; and a second terminal lower insulating member 155 installed between the second collector portion 140 connected to the second terminal column 151 and the cap plate 171.

[0075] However, those skilled in the art will appreciate that the second terminal portion 150 is described herein by way of example for better understanding of the example embodiments of the present disclosure, but the second terminal portion 150 may be implemented in any of a variety of shapes and structures.

[0076] In one embodiment, the case 160 may be formed as a substantially rectangular parallelepiped having a hollow top opening. The electrode assembly 110 may be inserted into the case 160 through the opening. In addition, the first collector portion 120 and the second collector portion 140 may also be placed in the case 160.

[0077] The cover assembly 170 may include a plate-shaped cover plate 171. For example, the cover plate 171 may be made of a thin plate and coupled to the opening of the housing 160 to close the opening. In one embodiment, the cover plate 171 includes an electrolyte injection portion 172, through which the electrolyte is injected into the housing 160. Once the electrolyte is injected, the electrolyte injection portion 172 is sealed by a plug 173. In addition, the cover plate 171 may include a vent 174, and a vent plate 175 configured to rupture when the internal pressure of the sealed housing 160 exceeds a certain pressure level (e.g., a preset pressure level) may be installed in the vent 174.

[0078] Although one or more example embodiments have been described to practice the secondary battery of the present disclosure, persons skilled in the art will understand that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as set forth in the following claims.

Claims

1. A secondary battery comprising: An electrode assembly, comprising: a first electrode plate and a second electrode plate, the first electrode plate and the second electrode plate being alternately stacked with a separator therebetween; a plurality of first electrode tabs overlapping each other at the same position and protruding outward from one of the opposite short side surfaces of the electrode assembly, the first electrode tab being an uncoated portion of the first electrode plate; and a fixing tape adhered to outer surfaces of the separator and the first electrode tab at each of the opposite long side surfaces of the electrode assembly, wherein a first end of the fixing tape is located on the separator and a second end of the fixing tape is located on the one short side surface of the electrode assembly; a first current collector portion coupled to the first electrode tab of the electrode assembly; and a casing accommodating the electrode assembly and the first current collector portion, The fixing tape includes two first fixing tapes respectively adhered to a first side end portion of one long side surface of the electrode assembly and the first electrode tab and a first side end portion of another long side surface of the electrode assembly and the first electrode tab.

2. The secondary battery according to claim 1, wherein The first electrode tabs are collected to be welded to the first current collector portion.

3. The secondary battery according to claim 1 or 2, wherein: Each of the two first fixing tapes includes a first region adhered to an outer surface of the separator and a second region adhered to an outer surface of the first electrode tab.

4. The secondary battery according to claim 3, wherein The second region of the first fixing tape is bent toward the one short side surface of the electrode assembly to cover a portion of the one short side surface.

5. The secondary battery according to claim 1 or 2, wherein: The electrode assembly further includes a plurality of second electrode tabs which are uncoated portions of the second electrode plate and protrude outward from the other of the opposite short side surfaces of the electrode assembly.

6. The secondary battery according to claim 5, wherein The fixing tape includes a second fixing tape adhered to an outer surface of the separator and an outer surface of the second electrode tab.

7. The secondary battery according to claim 5, wherein The separator extends perpendicular to a direction in which the first electrode tab and the second electrode tab protrude, and is bent in a Z-shaped configuration.

8. The secondary battery according to claim 6, wherein The second fixing tape includes a first region adhered to an outer surface of the separator and a second region adhered to an outer surface of the second electrode tab.

9. The secondary battery according to claim 5, wherein The fixing tape further includes two second fixing tapes respectively adhered to a second side end portion of the one long side surface of the electrode assembly and the second electrode tab and a second side end portion of the other long side surface of the electrode assembly and the second electrode tab.

10. The secondary battery according to claim 1, wherein The fixing tape comprises polyimide, polypropylene or polyethylene terephthalate.

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