Secondary battery

Abstract

Disclosed is a secondary battery capable of having sufficient squeezing force to induce strong bonding force during welding between a terminal and a current collector plate, the secondary battery comprising: an electrode assembly having a first electrode terminal tab and a second electrode terminal tab exposed to respective sides; a first current collector electrically connected to the first electrode terminal tab and comprising a central portion and an edge portion welded to the first electrode terminal tab; a shell accommodating the electrode assembly and the first current collector; a first cover plate sealing an opening of the shell; a first terminal mechanically and electrically connected to the first current collector and exposed to the outside of the first cover plate; and a support member between the central portion of the first current collector and the electrode assembly, wherein the central portion protrudes more toward the first cover plate than the edge portion.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0050197 filed on April 17, 2023, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Various embodiments of the present disclosure relate to a secondary battery. Background Art

[0004] Secondary batteries are a type of power storage system that provides a suitable energy density, can convert electrical energy into chemical energy and store it. Compared with non-rechargeable primary batteries, secondary batteries are rechargeable and are widely used in IT devices such as smartphones, mobile phones, notebook computers and tablet personal computers. Recently, in order to reduce environmental pollution, people's interest in electric vehicles has increased, and accordingly, high-capacity secondary batteries are being adopted in electric vehicles. Such secondary batteries have suitable characteristics such as high density, high power and stability.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the art and therefore it may contain information that does not constitute the prior art. Utility Model Content

[0006] The present disclosure relates to a secondary battery capable of improving weldability between a terminal and a current collector plate by forming sufficient pressing force during welding between the terminal and the current collector plate and by causing strong bonding force.

[0007] A secondary battery according to an embodiment of the present disclosure may include: an electrode assembly having a first electrode tab and a second electrode tab exposed to respective sides; a first current collecting portion electrically connected to the first electrode tab and including a center portion and an edge portion welded to the first electrode tab; a shell accommodating the electrode assembly and the first current collecting portion; a first cover plate sealing an opening of the shell; a first terminal mechanically and electrically connected to the first current collecting portion and exposed to the outside of the first cover plate; and a support member between the center portion of the first current collecting portion and the electrode assembly, wherein the center portion protrudes more toward the first cover plate than the edge portion.

[0008] The support may comprise insulating material.

[0009] The first current collecting part may include: a first current collector plate coupled to the first electrode tab by welding and including a center portion and an edge portion; and a second current collector plate contacting an outer surface of the first current collector plate and contacting and welded to an inner surface of the first terminal.

[0010] The central portion may have a central area protruding outward and an outer surface coupled to an inner side of the second current collector plate by welding, wherein the edge portion extends to both sides from the central portion and is welded to the first electrode tab of the electrode assembly.

[0011] The first current collector plate may further include a connection portion between the center portion and the edge portion and inclined in a direction from the center portion to the edge portion.

[0012] The second current collector plate may further include a protrusion protruding outward from a central region of the second current collector plate.

[0013] The outer surface of the protrusion may be coupled to the inner surface of the first terminal by contact and welding.

[0014] The secondary battery may further include an insulator between the first terminal and the first cap plate.

[0015] A size of a central portion of the first current collector plate may be smaller than a size of an inner surface of the second current collector plate.

[0016] The support member may press the first current collecting portion toward the first terminal.

[0017] The electrode assembly may include a zigzag stacked electrode assembly in which a positive electrode plate and a negative electrode plate are inserted at respective sides of a separator bent into a zigzag stack.

[0018] The separator may be fixed in the electrode assembly by a binder.

[0019] The adhesive may be on the inside of the support.

[0020] The support member may be a leaf spring.

[0021] The support member may include: an upper surface portion contacting a central portion of the first current collector plate; a lower surface portion opposite to the upper surface portion, contacting the electrode assembly and defining a space portion through which the corresponding cut ends are spaced apart from each other; and a side surface portion connecting the upper surface portion and the lower surface portion.

[0022] The space portion may be configured to allow adhesive to pass therethrough.

[0023] The support may include any one of a C-type, an Ω-type, or a bellows-type.

[0024] The opening may be defined in a region from an upper surface portion to a side surface portion or a lower surface portion in the support member.

[0025] The secondary battery may further include a cover sheet between the first current collecting portion and the first terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1is a perspective view of a secondary battery according to one or more embodiments of the present disclosure.

[0027] Figure 2 Taken along line 2-2' Figure 1 A cross-sectional view of a secondary battery in FIG.

[0028] Figure 3 for Figure 2 A partial cross-sectional view of an enlarged portion 3 in FIG.

[0029] Figure 4 To show Figure 1 An exploded perspective view of a terminal of a secondary battery before being coupled to a current collecting portion.

[0030] Figure 5A to Figure 5C for Figure 2 Plan view, front view and perspective view of the support parts in.

[0031] Figure 6 to Figure 8 To show Figure 2 A perspective view of one or more other embodiments of a support member in FIG. DETAILED DESCRIPTION

[0032] By referring to the detailed description and drawings of the embodiments, it is easier to understand the various aspects of some embodiments of the present disclosure and the methods for implementing these embodiments. The described embodiments are provided as examples so that the present disclosure will be thorough and complete, and will fully convey the various aspects of the present disclosure to those skilled in the art. Accordingly, redundant, irrelevant or unrelated to the description of the embodiments, or processes, elements and techniques that are not necessary for a person of ordinary skill in the art to fully understand the various aspects of the present disclosure can be omitted. Unless otherwise specified, in the entire drawings and written descriptions, the same reference numerals, characters or combinations thereof represent the same elements, and therefore their repeated descriptions can be omitted.

[0033] The described embodiments may have various modifications, may be embodied in different forms, and should not be construed as being limited to the embodiments illustrated herein. The present disclosure covers all modifications, equivalents, and alternatives within the scope of the ideas and techniques of the present disclosure. Further, each of the features of the various embodiments of the present disclosure may be combined in part or in whole or in combination with each other, and various technical interlocks and drives are possible. Each embodiment may be implemented independently of one another or may be implemented together in an associated manner.

[0034] In the drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity and / or descriptive purposes. In addition, the use of cross-hatching and / or shading in the drawings is generally provided to clarify the boundaries between adjacent elements. As such, the presence or absence of cross-hatching or shading does not convey or indicate any preference or requirement for specific materials, material properties, dimensions, proportions, commonalities between illustrated elements, and / or any other features, attributes, characteristics, etc., unless otherwise specified.

[0035] Various embodiments are described herein with reference to cross-sectional views as schematic diagrams of embodiments and / or intermediate structures. As such, variations in the shapes illustrated are expected due to, for example, manufacturing techniques and / or tolerances. Further, in order to describe embodiments according to the concepts of the present disclosure, the specific structural or functional descriptions disclosed herein are merely exemplary. Therefore, the embodiments disclosed herein should not be interpreted as being limited to the illustrated shapes of elements, layers, or regions, but include shape deviations caused by, for example, manufacturing.

[0036] For ease of explanation, spatial relative terms such as "under", "below", "lower", "lower side", "below", "above", "upper side" and the like can be used in this article to describe the relationship between an element or feature and another element or feature illustrated in the figure. It will be understood that, in addition to the orientation depicted in the accompanying drawings, spatial relative terms are intended to cover different orientations of the device in use or in operation. For example, if the device in the figure is turned over, the element or feature described as "under", "under" or "below" other elements or features will then be oriented to be "above" other elements or features. Therefore, the example terms "below" and "below" can cover both upper and lower orientations. The device can be oriented in other ways (for example, rotated 90 degrees or in other orientations), and the spatial relative descriptors used in this article should be interpreted accordingly. Similarly, when the first part is described as being arranged "on" the second part, this means that the first part is arranged on the upper or lower side of the second part, without being limited to its upper side based on the direction of gravity.

[0037] Further, the phrase "in a plan view" means when the object portion is viewed from above, while the phrase "in a schematic cross-sectional view" means a schematic cross-section obtained by vertically cutting the object portion from the side. The term "overlap" or "overlapping" means that the first object can be above or below or on one side of the second object, and vice versa. In addition, the term "overlap" may include layers, stacks, facing or facing, extending, covering or partially covering, or any other suitable term that a person of ordinary skill in the art will appreciate and understand. The expression "non-overlapping" may include such meanings as "except..." or "separated from..." or "offset relative to..." and any other suitable equivalents that a person of ordinary skill in the art will appreciate and understand. The terms "facing" and "facing" may mean that the first object may be directly or indirectly opposite to the second object. In the case where a third object intervenes between the first object and the second object, the first object and the second object may be understood to be indirectly opposite to each other, although still facing each other.

[0038] It will be understood that when an element, layer, region, or component is referred to as being "formed on," "on" another element, layer, region, or component, "connected to," or "(operationally or communicatively) coupled to" another element, layer, region, or component, it may be directly formed on, on, directly connected to, or coupled to another element, layer, region, or component, or indirectly formed on, on, indirectly connected to, or coupled to another element, layer, region, or component, such that there may be one or more intervening elements, layers, regions, or components. Additionally, this may be collectively referred to as being directly or indirectly coupled or connected, and integrally or non-integrally coupled or connected. For example, when a layer, region, or component is referred to as being "electrically connected" or "electrically coupled" to another layer, region, or component, it may be directly electrically connected or coupled to another layer, region, and / or component, or there may be intervening layers, regions, or components. However, "directly connected / directly coupled" or "directly on" means that one component is directly connected or coupled to another component, or is on another component, without intermediate components. In addition, in this specification, when a part of a layer, film, zone, plate, etc. is formed on another part, the formation direction is not limited to the upward direction, but includes forming the part on the side surface or in the downward direction. On the contrary, when a part of a layer, film, zone, plate, etc. is formed "below" another part, this includes not only the case where the part is "directly under" another part, but also the case where another part further exists between the part and the other part. At the same time, other expressions describing the relationship between components, such as "between...", "between..." or "adjacent to..." and "directly adjacent to...", can be interpreted similarly. In addition, it will also be understood that when an element or layer is referred to as "between" two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intermediate elements or layers may also exist.

[0039] For the purposes of this disclosure, expressions such as "at least one of..." or "any one of..." or "one or more of..." when preceding or following a list of elements modify the entire list of elements without modifying the individual elements of the list. For example, "at least one of X, Y, and Z," "at least one selected from the group consisting of X, Y, and Z," may be interpreted as any combination of only X, only Y, only Z, two or more of X, Y, and Z, such as, for example, XYZ, XYY, YZ, and ZZ, or any variation thereof. Similarly, expressions such as "at least one of A and B" may include A, B, or A and B. As used herein, "or" generally means "and / or," and the term "and / or" includes any and all combinations of one or more of the associated listed items. For example, expressions such as "A and / or B" may include A, B, or A and B. Similarly, expressions such as "at least one of...", "a plurality of...", "one of..." and other prepositional phrases when preceding or following a list of elements modify the entire list of elements without modifying the individual elements of the list.

[0040] It will be understood that although the terms "first", "second", "third", etc. can be used in this article to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms do not correspond to a specific order, position or advantage, and are only used to distinguish an element, member, component, region, area, layer, section or part from another element, member, component, region, area, layer, section or part. Therefore, without departing from the spirit and scope of the present disclosure, the first element, component, region, layer or section described below can be referred to as the second element, component, region, layer or section. Describing an element as a "first" element may not require or imply the presence of a second element or other elements. The terms "first", "second", etc. can also be used in this article to distinguish different element categories or groups. For the sake of brevity, the terms "first", "second", etc. can represent "first class (or first group)", "second class (or second group)", etc. respectively.

[0041] In the example, the x-axis, y-axis and / or z-axis are not limited to the three axes of the rectangular coordinate system and can be interpreted in a broader sense. For example, the x-axis, y-axis and z-axis can be perpendicular to each other, or can represent different directions that are not perpendicular to each other. The same applies to the first, second and / or third directions.

[0042] The terms used herein are only used for the purpose of describing the embodiments and are not intended to limit the present disclosure. As used herein, the singular form "one" is intended to also include the plural form, and the plural form is also intended to include the singular form, unless the context clearly indicates otherwise. It will be further understood that the terms "including", "having" and "comprising" when used in this specification specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups.

[0043] When one or more embodiments can be implemented differently, a specific process order can be performed in a different order than described. For example, two processes described in succession can be performed substantially simultaneously, or in a reverse order to the described order.

[0044] As used herein, the terms "substantially," "about," "approximately," and similar terms are used as terms of approximation rather than terms of degree, and are intended to account for the inherent deviations in measured or calculated values ​​that one of ordinary skill in the art would recognize. "Approximately" or "approximately" as used herein include specified values ​​and averages within an acceptable range of deviation for a particular value determined by one of ordinary skill in the art, taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "approximately" may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of a specified value. Further, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure."

[0045] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It will 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 art and / or this specification, and should not be interpreted in an idealized or overly formal sense, unless explicitly defined as such herein.

[0046] refer to Figure 1 , showing a perspective view of a secondary battery according to one or more embodiments of the present disclosure. Figure 2 , showing the section taken along line 2-2' Figure 1 A cross-sectional view of a secondary battery in FIG. Figure 3 , showing Figure 2 Hereinafter, when describing the secondary battery 100 of the present disclosure, the following will be based on Figure 1 The structure of the secondary battery 100 will be described with reference to the secondary battery 100 shown in FIG.

[0047] like Figure 1 to Figure 3As shown in FIG. 1 , the secondary battery 100 may include an electrode assembly 110 , a first current collecting portion 120 , a first terminal 130 , a second current collecting portion 140 , a second terminal 150 , a case 160 , a first cap assembly 170 , and a second cap assembly 180 .

[0048] The electrode assembly 110 may be formed by winding or stacking a laminate of a first electrode plate 111, a separator 113, and a second electrode plate 112 formed in a thin plate shape or a film shape. If the electrode assembly 110 is a wound laminate, the winding axis may be parallel to the longitudinal direction (e.g., y direction) of the housing 160. In addition, the electrode assembly 110 may be a stacked type rather than a wound type, and the shape of the electrode assembly 110 is not limited in the present disclosure. In addition, the electrode assembly may be a Z-shaped stacked electrode assembly, in which the positive electrode plate and the negative electrode plate are inserted into the corresponding sides of the separator bent into a Z-shaped stack. In addition, one or more electrode assemblies 110 may be stacked so that the long sides of the electrode assemblies 110 are adjacent to each other and accommodated in the housing 160. In the present disclosure, the number of electrode assemblies 110 is not limited.

[0049] The first electrode plate 111 of the electrode assembly 110 may serve as a negative electrode plate, and the second electrode plate 112 may serve as a positive electrode plate. In one or more embodiments, the reverse is also possible.

[0050] The first electrode plate 111 may be formed by applying a first electrode active material such as graphite or carbon to a first electrode current collector plate made of a metal foil such as copper, copper alloy, nickel or nickel alloy, and may include a first electrode terminal tab (or a first uncoated portion), which is an area where the first electrode active material is not applied. The first electrode terminal tab may be a channel for current to flow between the first electrode plate 111 and the first current collector 120. In one or more embodiments, when manufacturing the first electrode plate 111, the first electrode terminal tab may be formed by pre-cutting to protrude to one side, and may protrude more to one side than the separator 113 without separate cutting.

[0051] The second electrode plate 112 may be formed by applying a second electrode active material such as a transition metal oxide to a second electrode current collector plate made of a metal foil such as aluminum or an aluminum alloy, and may include a second electrode terminal tab (or a second uncoated portion), which is an area where the second electrode active material is not applied. The second electrode terminal tab may be a passage for current to flow between the second electrode plate 112 and the second current collector 140. In one or more embodiments, when manufacturing the second electrode plate 112, the second electrode terminal tab may be formed by pre-cutting to protrude to the other side, and may protrude more to the other side than the separator 113 without separate cutting.

[0052] In one or more embodiments, the first electrode tab may be located on the left side of the electrode assembly 110, and the second electrode tab may be located on the right side of the electrode assembly 110. Here, for ease of explanation, the terms left and right are based on Figure 1 and Figure 2 The secondary battery 100 shown in FIG. 1 and the position of the secondary battery 100 may be changed when the secondary battery 100 is rotated left and right or up and down. Figure 1 to Figure 3 Each component is described with reference to the secondary battery 100 shown in FIG.

[0053] In one or more embodiments, the separator 113 is located between the first electrode plate 111 and the second electrode plate 112 to reduce or prevent the possibility of a short circuit and enable the movement of lithium ions, and may include polyethylene, polypropylene, or a composite film of polyethylene and polypropylene. In addition, the separator 113 may be replaced with an inorganic solid electrolyte that does not require a liquid or gel electrolyte, such as a sulfide, oxide, or phosphate compound.

[0054] The first electrode tab of the first electrode plate 111 and the second electrode tab of the second electrode plate 112 are located on the corresponding sides of the electrode assembly 110. In one or more embodiments, the electrode assembly 110 may be contained in the housing 160 together with the electrolyte. In one or more embodiments, the electrolyte may include a lithium salt such as LiPF6 or LiBF4 in an organic solvent such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC) or dimethyl carbonate (DMC). In addition, the electrolyte may be a liquid phase or a gel phase. In one or more embodiments, if an inorganic solid electrolyte is used, a gel or liquid electrolyte may be omitted.

[0055] In addition, the electrode assembly 110 is positioned such that the first and second current collecting portions 120 and 140 are welded and connected to the first and second electrode tabs of the first and second electrode plates 111 and 112 exposed to the respective sides.

[0056] The first current collecting portion 120 may be made of metal, and may electrically connect the first electrode plate 111 and the first terminal 130 to each other. Figure 4 , shows the display Figure 1 An exploded perspective view of a terminal of a secondary battery in FIG. 1 before being connected to a current collecting portion. Figure 4 The structure and connection relationship of the first current collecting portion 120 are described.

[0057] The first current collecting portion 120 may be received inside the case 160 and interposed between the first cap plate 171 and the electrode assembly 110 .

[0058] The first current collector 120 may include a first current collector plate 121 contacting and coupled to the first electrode tab (eg, the first uncoated portion) of the first electrode plate 111, and may include a second current collector plate 122 contacting and coupled to the first terminal 130. The first current collector 120 may be made of copper or a copper alloy.

[0059] The first current collector plate 121 extends along a first direction (e.g., x direction) which is a longitudinal direction of the first cap plate 171 which is at one side of the electrode assembly 110 and may be substantially in a plate shape. The first current collector plate 121 may be coupled to the first electrode plate 111 by welding in a state of contacting the first electrode tab exposed to one side of the electrode assembly 110, and thus may have the same polarity as that of the first electrode plate 111.

[0060] The first current collector plate 121 may include a central portion 121 a protruding outwardly in a central region and edge portions 121 b extending toward both sides from the central portion 121 a .

[0061] The center portion 121 a may have an outer surface coupled to the inner side of the second current collector plate 122 by welding.

[0062] The edge portion 121b may have an inner surface that contacts and is welded to the first electrode tab of the electrode assembly 110 and then is coupled to the first electrode tab. The center portion 121a may protrude in an outward direction at a location where the first cap plate 171 is located compared to the edge portion 121b. The center portion 121a may be spaced apart from one side of the electrode assembly 110.

[0063] A connection portion 121c inclined in a direction from the center portion 121a to the edge portion 121b may be formed between the center portion 121a and the edge portion 121b. Here, the center portion 121a and the edge portion 121b may be parallel to each other. In addition, a bend may be provided between the center portion 121a and the connection portion 121c and between the connection portion 121c and the edge portion 121b. The center portion 121a is positioned closer to the first cover plate 171 side than the edge portion 121b.

[0064] In one or more embodiments, the first current collector plate 121 may include a connection portion 121 c and an edge portion 121 b provided on both sides in a first direction (eg, x-direction) with respect to a center portion 121 a .

[0065] The size of the central portion 121a of the first current collector plate 121 may be smaller than the size of the inner surface of the second current collector plate 122. That is, the length L1 of the central portion 121a of the first current collector plate 121 in the first direction (e.g., x direction) may be smaller than the length L2 of the inner surface of the second current collector plate 122. In addition, the area of ​​the central portion 121a of the first current collector plate 121 may be smaller than the area of ​​the inner surface of the second current collector plate 122.

[0066] The second collector plate 122 extends along the first direction (eg, x direction) and may be substantially in the shape of a plate. The second collector plate 122 may contact and be welded to the outer surface of the first collector plate 121, and may contact and be welded to the inner surface of the first terminal 130. The second collector plate 122 may include a body portion 122a.

[0067] The second current collector plate 122 may further include a protrusion 122b protruding outward on an outer surface of a central region of the body portion 122a. The outer surface of the protrusion 122b is coupled to the inner surface of the first terminal 130 by contact and welding.

[0068] The inner surface of the second collector plate 122 may have a size greater than the center portion 121a of the first collector plate 121. That is, the length L2 of the inner surface of the second collector plate 122 in the first direction (eg, x direction) may be greater than the length L1 of the center portion 121a of the first collector plate 121.

[0069] The first terminal 130 is made of metal, can contact and can be welded to the protrusion 122b, and then electrically connected to the protrusion 122b. In one or more embodiments, the first terminal 130 may include a first terminal plate 131 and a first terminal groove 132. The first terminal 130 may be made of aluminum or an aluminum alloy. The first terminal 130 and the first current collector 120 may be made of different metals. In one or more embodiments, a covering sheet may be further provided between the first terminal 130 and the first current collector 120. The covering sheet may couple and electrically connect the first terminal 130 and the first current collector 120, which may be made of different metals, to each other. The covering sheet may be a sheet in which an aluminum sheet and a copper sheet are combined by thermal compression. In one or more embodiments, the covering sheet may be a sheet in which 2T of aluminum and 0.5 to 0.7T of copper are combined by thermal compression. The aluminum sheet of the covering sheet may be coupled to the first terminal 130 by welding, and the copper sheet may be coupled to the first current collector 120 by welding.

[0070] The first terminal plate 131 may be located outside or above the first cap plate 171. In addition, the first terminal groove 132 may be provided in an inward direction from the outer surface of the first terminal plate 131. The first terminal plate 131 may have a thinner region in which the first terminal groove 132 is provided than other regions of the first terminal plate 131. The first terminal plate 131 may be coupled to the second current collector plate 122 by welding through the first terminal groove 132 from the outside of the first cap plate 171.

[0071] The first terminal groove 132 may be located in a partial region of the first terminal plate 131 . The first terminal groove 132 may be located in an approximately central region of the first terminal plate 131 , but may be located in a region corresponding to the current collector through-hole of the second current collector plate 122 .

[0072] In addition, a first insulator 172 may be further interposed between the first terminal plate 131 and the first cap plate 171. In addition, a first sealing gasket 173 may be further interposed between the outer surface of the first terminal plate 131 and the first cap plate 171, thereby sealing the first terminal 130 and the first cap plate 171 from each other.

[0073] The first terminal plate 131 may contact and be coupled to the second current collector plate 122 of the first current collecting portion 120 on one side located at the right side.

[0074] In the first terminal 130 , the first terminal plate 131 may be exposed and may protrude from the outside of the first cap plate 171 .

[0075] The second current collector 140 is made of metal and may electrically connect the second electrode plate 112 and the second terminal 150 to each other. The second current collector 140 is a metal plate and may include a third current collector plate 141 contacting and coupled to the second electrode tab of the second electrode plate 112 and a fourth current collector plate 142 contacting and coupled to the second terminal 150. In addition, the second current collector 140 may be coupled to the electrode assembly 110 and the second terminal 150 in a symmetrical form with the first current collector 120 based on the electrode assembly 110. In addition, the second current collector 140 may be made of aluminum or an aluminum alloy.

[0076] The second terminal 150 is made of metal and may be electrically connected to the second current collecting portion 140. In one or more embodiments, the second terminal 150 may include a second terminal plate 151 and a second terminal groove 152.

[0077] Here, the second terminal plate 151 may be located inside the second cap plate 181. In one or more embodiments, the second insulator 182 may be further interposed between the second terminal plate 151 and the second cap plate 181. In addition, the second sealing gasket 183 may be further interposed between the second terminal plate 151 and the second cap plate 181.

[0078] The second terminal 150 may have the same shape and structure as those of the first terminal 130. However, the second terminal 150 may be coupled to the electrode assembly 110 through the second current collecting portion 140 in a symmetrical form with the first terminal 130 based on the electrode assembly 110. In addition, the second terminal 150 may be made of aluminum or an aluminum alloy. In addition, the second terminal 150 and the second current collecting portion 140 are made of the same metal and, therefore, may be directly coupled to each other by welding.

[0079] The case 160 has a substantially hollow rectangular parallelepiped shape with openings 161 , 162 formed at both sides, and the electrode assembly 110 coupled to the first and second current collecting parts 120 , 140 may be inserted into the inside of the case 160 through the openings 161 , 162 .

[0080] The housing 160 may include a rectangular upper surface and a lower surface extending along a second direction (e.g., y direction) as a longitudinal direction of the housing 160, and two rectangular long side surfaces extending along the second direction (e.g., y direction) and connecting long sides of the upper surface and the lower surface. The housing 160 may have an upper surface, a lower surface, and two long side surfaces formed integrally with each other.

[0081] The housing 160 may have an exhaust hole passing through the long side surface. The safety vent 163 may be installed in the exhaust hole of the housing 160. In addition, the safety vent 163 may have a cutout that is thinner than other areas and can be opened by a certain pressure (eg, a set pressure).

[0082] The first cap assembly 170 may be coupled to the opening 161 of the left side of the housing 160. In one or more embodiments, the first cap assembly 170 may include a first cap plate 171, a first insulator 172, a first sealing gasket 173, a first support 174, and a first adhesive 175.

[0083] The first cap plate 171 has a flat rectangular plate shape and may seal the left side opening 161 of the case 160. The first cap plate 171 may have a terminal hole passing through between the outer surface and the inner surface and an electrolyte injection port. The protrusion 122b of the second current collector plate 122 may pass through the terminal hole of the first cap plate 171 and may be coupled to the first terminal plate 131. In addition, after the first cap plate 171 is coupled to the case 160 and after the electrolyte is injected into the case 160, the electrolyte injection port may be sealed by a plug 176.

[0084] The first insulator 172 may be interposed between the first cap plate 171 and the second current collector plate 122. The first insulator 172 may be in close contact with the first cap plate 171, and may also be in contact with the first sealing gasket 173. The first insulator 172 may be made of an insulating material, and may insulate the first cap plate 171 and the first terminal plate 131 from each other.

[0085] In addition, the first sealing gasket 173 is made of an insulating material and is provided between the first cap plate 171 and the first terminal plate 131, or is provided on the outer surface of the first terminal plate 131, thereby sealing the first cap plate 171 and the first terminal plate 131 from each other. The first sealing gasket 173 reduces or prevents external moisture from penetrating into the secondary battery 100, or reduces or prevents the possibility of leakage of the electrolyte contained in the secondary battery 100. The first sealing gasket 173 may be manufactured together with the first insulator 172 by an insert injection method to be installed.

[0086] That is, the first cap plate 171 may be electrically isolated from the first terminal 130 and the second current collector plate 122 via the first insulator 172 and the first sealing gasket 173 .

[0087] Figure 5A to Figure 5C for Figure 2 Plan view, front view and perspective view of the support parts in.

[0088] The first support 174 may be interposed between the first current collector 120, for example, the central portion 121a thereof, and the electrode assembly 110. The first support 174 may be made of an insulating material, and may press the first current collector 120 toward the first terminal 130. The first support 174 may bring the second current collector plate 122 of the first current collector 120 and the first terminal 130 into close contact with each other by pressing the first current collector 120 toward the first terminal 130. That is, by means of the first support 174, the second current collector plate 122 and the first terminal 130 are welded and coupled to each other while in close contact with each other, thereby improving the bonding strength.

[0089] The first support member 174 may be a leaf spring. Figure 5A to Figure 5C In the embodiment, the first support member 174 may be a plate spring and may be formed into a C-shaped structure, wherein both sides of the first support member 174 are bent at least twice.

[0090] In one or more embodiments, the first support member 174 may include an upper surface portion 174a, a lower surface portion 174c opposite to the upper surface portion 174a, and a side surface portion 174b connecting the upper surface portion 174a and the lower surface portion 174c. The upper surface portion 174a may be flat to contact an area of ​​the inner surface of the first collector plate 121, for example, to contact the central portion 121a of the first collector plate 121. In one or more embodiments, the upper surface portion 174a may have openings 174e formed on both sides to facilitate bending and improve elasticity. The upper surface portion 174a may have an area smaller than that of the first collector plate 121. The lower surface portion 174c is formed flat to contact a local area of ​​one side of the electrode assembly 110, and has a space portion 174d at a substantially central portion of the lower surface portion 174c so that the lower surface portion 174c is divided in a direction perpendicular to the first direction (e.g., the x direction). The lower surface portion 174c may be located on both sides of the space portion 174d in a separated form in a direction perpendicular to the first direction (e.g., the x direction), for example, the corresponding cutting ends are spaced apart from each other in the space portion 174d by the space portion 174d. The side surface portion 174b may be provided on both sides of the upper surface portion 174a and the lower surface portion 174c to connect the upper surface portion 174a and the lower surface portion 174c. The opening 174e may be formed from the upper surface portion 174a to a partial area of ​​the side surface portion 174b and / or the lower surface portion 174c.

[0091] The space portion 174d is located inside the first support member 174 and on the lower surface portion 174c so that the first adhesive 175 can be fixed therethrough. The first adhesive 175 is formed inside the first support member 174 so that the separator of the electrode assembly 110 can be inserted into the space portion 174d and fixed to the space portion 174d. The first adhesive 175 is located on the upper surface of the lower surface portion 174c in the inward direction of the first support member 174.

[0092] In one or more other embodiments, the first support member 174 may be a plate spring and may have a C-shaped structure without an opening 174e, such as Figure 6 Shown in.

[0093] In one or more other embodiments, the first support member 174 may be a plate spring, and may be an Ω-shaped support member, wherein the lower surface portion 274c extends outward from the side surface portion 174b, such as Figure 7 Similar to Figure 5C In contrast to the first support member 174 shown in FIG. 1 , the support member 274 may further include an opening.

[0094] In one or more other embodiments, the first support member 174 may be a plate spring, and may be formed as a bellows-type support member 374, wherein at least one bend is provided on the side surface portion 374b, such as Figure 8 Similar to Figure 5C In contrast to the first support member 174 shown in FIG. 1 , the support member 374 may further include an opening.

[0095] The second cover assembly 180 may be coupled to the opening 162 on the right side of the housing 160. In one or more embodiments, the second cover assembly 180 may include a second cover plate 181, a second insulator 182, a second sealing gasket 183, a second support 184, and a second adhesive 185. The second cover assembly 180 may be the same as the first cover assembly 170 in shape and structure. In addition, the coupling shape and structure of the second cover assembly 180 and the second terminal 150 may be the same as the coupling shape and structure of the first cover assembly 170 and the first terminal 130. However, the coupling shape of the second cover assembly 180 and the second terminal 150 may be symmetrical based on the coupling shape of the housing 160 with the first cover assembly 170 and the first terminal 130.

[0096] In the secondary battery 100, the first cap assembly 170 coupled to the first terminal 130 is coupled to one side opening of the housing 160, and the second cap assembly 180 coupled to the second terminal 150 is coupled to the other side opening of the housing 160, and thus, the first terminal 130 and the second terminal 150 are located at respective sides of the housing 160. By including the first terminal 130 and the second terminal 150 on both sides of the secondary battery 100, respectively, when a plurality of secondary batteries 100 are combined in a module form, in one or more embodiments, cooling members may be coupled to the upper region and the lower region of the housing 160, respectively, to reduce degradation of the secondary battery 100 and improve cooling performance.

[0097] In one or more embodiments, in a state in which long side surfaces of a plurality of secondary batteries 100 are positioned to face each other, the battery module may electrically connect the first terminals and / or the second terminals respectively exposed to both sides.

[0098] In addition, by including the first terminal 130 and the second terminal 150 on both sides of the secondary battery 100, respectively, when a plurality of secondary batteries 100 are combined in a module form, a charge / discharge current can flow through each terminal in two directions, and thus, degradation can be reduced compared to a case where a charge and discharge current flows through two terminals on one side. In addition, when a plurality of secondary batteries 100 are combined in a module form, each terminal can be connected in two directions, and thus high space utilization can be achieved.

[0099] As described above, in the secondary battery of the present disclosure, by forming a sufficient pressing force when welding the terminal and the current collector plate, the weldability of the terminal and the current collector plate may be improved, and a strong bonding force may be induced.

[0100] In addition, in the secondary battery of the present disclosure, by including a support member between the current collector plate and the electrode assembly, damage to the electrode assembly can be reduced or prevented even if the amount of interference is excessive, and impact applied to the electrode assembly due to vibration after welding can be weakened.

[0101] Although the foregoing embodiments are merely some embodiments for implementing the secondary battery according to the present disclosure, those skilled in the art will understand that various changes in form and details may be made without departing from the spirit and scope of the present disclosure as defined by the appended claims, and that functional equivalents thereof will be included therein.

Claims

1. A secondary battery, characterized in that: The secondary battery comprises: An electrode assembly having a first electrode tab and a second electrode tab exposed to respective sides; a first current collecting portion electrically coupled to the first electrode tab and comprising a central portion and an edge portion welded to the first electrode tab; a housing for accommodating the electrode assembly and the first current collecting portion; a first cover plate, sealing an opening of the housing; a first terminal mechanically and electrically coupled to the first current collecting portion and exposed to the outside of the first cap plate; and a support member between the central portion of the first current collecting portion and the electrode assembly, The central portion protrudes further toward the first cover plate than the edge portion.

2. The secondary battery according to claim 1, characterized in that: The support member is made of insulating material.

3. The secondary battery according to claim 1, characterized in that: The first current collecting portion comprises: a first current collector plate coupled to the first electrode tab by welding and including the central portion and the edge portion; and The second current collector plate contacts the outer surface of the first current collector plate and contacts and is welded to the inner surface of the first terminal.

4. The secondary battery according to claim 3, characterized in that: The central portion has a central area protruding outward and an outer surface coupled to the inner side of the second current collector plate by welding, and The edge portion extends from the central portion to both sides and is welded to the first electrode tab of the electrode assembly.

5. The secondary battery according to claim 4, characterized in that: The first current collector plate further includes a connection portion between the center portion and the edge portion and inclined in a direction from the center portion to the edge portion.

6. The secondary battery according to claim 4, characterized in that: The second current collector plate further includes a protrusion protruding outward from a central region of the second current collector plate.

7. The secondary battery according to claim 6, characterized in that: An outer surface of the protrusion is coupled to the inner surface of the first terminal by contact and welding.

8. The secondary battery according to claim 1, characterized in that: The secondary battery further includes an insulator between the first terminal and the first cap plate.

9. The secondary battery according to claim 3, characterized in that: The size of the central portion of the first current collector plate is smaller than the size of the inner surface of the second current collector plate.

10. The secondary battery according to claim 1, characterized in that: The support member presses the first current collecting portion toward the first terminal.

11. The secondary battery according to claim 1, characterized in that: The electrode assembly includes a zigzag stacked electrode assembly in which a positive electrode plate and a negative electrode plate are inserted at respective sides of a separator bent into a zigzag stack.

12. The secondary battery according to claim 11, characterized in that: The separator is fixed in the electrode assembly by a binder.

13. The secondary battery according to claim 12, characterized in that: The adhesive is inside the support.

14. The secondary battery according to claim 1, characterized in that: The supporting member is a plate spring.

15. The secondary battery according to claim 14, characterized in that: The support member comprises: an upper surface portion contacting the central portion of the first current collecting portion; a lower surface portion, opposite to the upper surface portion, contacting the electrode assembly and defining a space portion through which the respective cut ends are spaced apart from each other; and The side surface portion connects the upper surface portion and the lower surface portion.

16. The secondary battery according to claim 15, characterized in that: The space portion is configured to allow the adhesive to pass therethrough.

17. The secondary battery according to claim 15, characterized in that: The support member includes any one of a C-type, an Ω-type or a bellows-type.

18. The secondary battery according to claim 15, characterized in that: An opening is defined in the support member at a region from the upper surface portion to the side surface portion or the lower surface portion.

19. The secondary battery according to claim 1, characterized in that: The secondary battery further includes a cover sheet between the first current collecting portion and the first terminal.

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