Battery cell and battery module comprising same

Abstract

The present disclosure relates to a battery cell and a battery module comprising same, and a technical problem to be solved is to provide a battery module which enables improvements in welding strength between a cell terminal and a busbar. To this end, the present disclosure provides a battery cell which includes an electrode assembly, a busbar which is electrically connected to the battery cell, and a welding fixing part which fixes the busbar to the battery cell by welding.

Description

Battery cells and battery modules comprising the same

[0001] The present disclosure relates to a battery cell and a battery module including the same capable of improving the welding strength of a cell terminal and a bus bar.

[0002] Typically, a battery module is a battery assembly comprised of a fixed number of battery cells, grouped together and housed within a frame to protect them from external shock, heat, and vibration. A module consists of multiple cells connected in series and / or parallel and is embedded within a mechanical structure.

[0003] While commonly referred to as a "battery," a closer look reveals that it's comprised of "cells," "modules," and "packs." Battery cells each store and release energy. Because their capacity is small on their own, they are grouped together to form modules, which are then combined to form larger packs. The source of a battery lies in the cells, and the units that connect them are then grouped into modules and then packs.

[0004] Multiple battery cells are electrically connected by busbars and are thus connected in series and / or parallel.

[0005] The above-described information disclosed in the background technology of this invention is only intended to improve understanding of the background of the present invention, and therefore may include information that does not constitute prior art.

[0006] The present invention provides a battery cell capable of improving the welding strength of a cell terminal and a bus bar, and a battery module including the same.

[0007] The present invention provides a battery cell and a battery module including the same that can facilitate the discharge of gas generated when welding a bus bar to a cell terminal.

[0008] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0009] According to one embodiment of the present invention for solving the above technical problem, a battery cell may include: an electrode assembly; a case accommodating the electrode assembly; a cap plate sealing an opening of the case; and a terminal portion connected to the cap plate and having a guide portion for discharging gas generated during welding with a bus bar to the outside.

[0010] For example, a battery cell may include a housing that accommodates an electrode assembly and a terminal portion that is electrically connected to the electrode assembly, protrudes outwardly from the housing, faces a bus bar, and is electrically connected to the bus bar through a welded fixing portion.

[0011] For example, gas generated during the creation of a welding fixture can be discharged to the outside of the terminal portion through the space formed between the terminal portion and the bus bar.

[0012] For example, a housing may include a case and a cap plate.

[0013] For example, the terminal portion may include a terminal rivet electrically connected to the electrode assembly, one end of which is positioned on the inside of the housing and the other end of which is positioned on the outside of the housing, and a terminal plate electrically connected to the terminal rivet and having an area in contact with the bus bar and an area spaced apart from the bus bar.

[0014] For example, the terminal plate may include a plate body positioned on the outside of the housing and electrically connected to a terminal rivet, a connecting hole portion forming a hole in the plate body in an up-and-down direction for positioning the terminal rivet, a first guide portion forming a groove portion on the outside of the connecting hole portion along a position where a welding fixing portion is formed, and a second guide portion forming a groove portion connecting the first guide portion and the outside of the plate body.

[0015] For example, the first guide portion may form a groove portion extending in a ring shape along the outer circumference of the connecting hole portion.

[0016] For example, the gap between the first guide portion and the bus bar may be 0.1 to 0.4 mm.

[0017] For example, the second guide section may be provided in multiples.

[0018] For example, the second guide section can be installed radially around the connecting hole section.

[0019] For example, the second guide section can be installed in a cross shape centered on the connecting hole section.

[0020] For example, the terminal plate may further include a terminal surface that protrudes from the plate body in a direction toward the bus bar and makes surface contact with the bus bar and is electrically connected thereto.

[0021] For example, the terminal top surface may be located above the first guide section.

[0022] A battery module according to one embodiment of the present invention may include a battery cell having a terminal portion electrically connected to an electrode assembly, a bus bar electrically connected to the terminal portion, and a welding fixing portion that fixes the bus bar to the terminal portion by welding.

[0023] For example, gas generated during the creation of a welding fixture can be discharged to the outside of the terminal portion through the space formed between the terminal portion and the bus bar.

[0024] For example, the bus bar may include a first connecting plate that is in contact with and electrically connected to a terminal portion, a second connecting plate that is installed spaced apart from the first connecting plate and is in contact with and electrically connected to an adjacent terminal portion, and a curved connecting portion that connects the first connecting plate and the second connecting plate and forms a curved surface.

[0025] For example, the terminal portion may include a terminal rivet electrically connected to the electrode assembly, one end of which is positioned on the inside of the housing of the battery cell and the other end of which is positioned on the outside of the housing, and a terminal plate electrically connected to the terminal rivet and having an area in contact with a bus bar and an area spaced apart from the bus bar.

[0026] For example, the terminal plate may include a plate body positioned on the outside of the housing and electrically connected to a terminal rivet, a connecting hole portion forming a hole in the plate body in an up-and-down direction for positioning the terminal rivet, a first guide portion forming a groove portion on the outside of the connecting hole portion along a position where a welding fixing portion is formed, and a second guide portion forming a groove portion connecting the first guide portion and the outside of the plate body.

[0027] For example, the gas generated when creating a welding fixture can move along the first guide section and then be discharged to the outside of the terminal plate along the second guide section.

[0028] For example, the first guide portion may form a groove portion extending in a ring shape along the outer circumference of the connecting hole portion.

[0029] For example, the welding fixing member is a welding seam created by a welding operation that fixes the busbar to the terminal plate, and may form a projection that extends from the busbar and is fixed to the first guide member.

[0030] For example, the terminal plate may further include a terminal surface that protrudes from the plate body in a direction toward the bus bar and makes surface contact with the bus bar and is electrically connected thereto.

[0031] For example, the first guide section and the bus bar may be spaced apart at a set interval.

[0032] According to the present invention, a wide welding joint area can be secured by inducing the discharge of gas generated during busbar welding, thereby ensuring high strength compared to the same welding conditions.

[0033] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects that are not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0034] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0035] FIG. 1 is a perspective view illustrating a battery module according to one embodiment of the present invention.

[0036] Figure 2 is a front view of a battery module according to one embodiment of the present invention.

[0037] FIG. 3 is a perspective view illustrating a battery cell according to one embodiment of the present invention.

[0038] Figure 4 is a cross-sectional view of a battery cell according to one embodiment of the present invention.

[0039] Figure 5 is a perspective view illustrating a bus bar according to one embodiment of the present invention.

[0040] Fig. 6 is a cross-sectional view showing a state in which a bus bar according to one embodiment of the present invention is fixed to a terminal portion.

[0041] FIG. 7 is a perspective view illustrating a battery cell having a terminal portion according to one embodiment of the present invention.

[0042] Figure 8 is a perspective view illustrating a terminal portion according to one embodiment of the present invention.

[0043] Fig. 9 is a perspective view showing the position where a welding fixing part is installed in a terminal section according to one embodiment of the present invention.

[0044] Fig. 10 is a plan view illustrating a terminal portion according to one embodiment of the present invention.

[0045] Fig. 11 is a plan view illustrating a terminal portion according to another embodiment of the present invention.

[0046] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their conventional or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of filing this application.

[0047] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0048] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0049] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0050] Although the terms "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0051] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0052] Any configuration being placed “on top (or bottom)” of a component or “on top (or bottom)” of a component may mean not only that any configuration is placed in contact with the top (or bottom) of the component, but also that other configurations may be interposed between the component and any configuration placed on (or under) the component.

[0053] Additionally, when a component is described as being “on,” “connected to,” or “coupled to” another component, it should be understood that the components may be directly connected or coupled to one another, but that other components may also be “interposed” between the components, or that each component may be “connected,” “coupled,” or “connected” through other components.

[0054] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, the use of "may" when describing embodiments of the present disclosure refers to "one or more embodiments of the present disclosure." Expressions such as "one or more" and "one or more" preceding a list of elements modify the list as a whole and do not modify individual elements in the list.

[0055] When reference is made throughout the specification to “A and / or B,” this means A, B, or A and B, unless otherwise stated, and when reference is made to “C to D,” this means C or more and D or less, unless otherwise stated.

[0056] When phrases such as "at least one of A, B, and C," "at least one of A, B, or C," "at least one selected from the group A, B, and C," or "at least one selected from A, B, and C," are used to specify a list of elements A, B, and C, the phrases can refer to any suitable combination.

[0057] The term "use" may be considered synonymous with the term "utilize." As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation rather than degrees, and are intended to take into account inherent variations in measured or calculated values ​​that would be recognized by those skilled in the art.

[0058] Although terms such as first, second, third, etc. may be used herein 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 are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could also be termed a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0059] For ease of description, spatially relative terms such as "beneath," "below," "lower," "above," "upper," and the like may be used herein to describe the relationship of one element or feature to another element(s) or feature(s) as depicted in the drawings. It will be understood that spatially relative positions encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the drawings is turned over, an element described as "beneath" or "lower" another element would be understood to be "above" or "upper" the other element. Thus, the term "beneath" can encompass both the above and below orientations.

[0060] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure. A battery module (1) according to an embodiment of the present invention will be described with reference to the drawings.

[0061] Fig. 1 is a perspective view illustrating a battery module (1) according to one embodiment of the present invention, and Fig. 2 is a front view of the battery module (1) according to one embodiment of the present invention. As illustrated in Figs. 1 and 2, the battery module (1) according to the present invention may include a terminal portion (170), a plurality of battery cells (100) arranged in one direction, and a bus bar (200) connecting the battery cells (100) to adjacent battery cells (100).

[0062] First, the battery cell (100) may be composed of a battery housing (120), an electrode assembly (110) housed in the battery housing (120), and an electrolyte. The electrode assembly (110) and the electrolyte electrochemically react to generate energy. A terminal portion (170) electrically connected to a bus bar (200) and a vent hole (151b) serving as a discharge passage for gases generated internally may be provided on one side of the battery cell (100). The terminal provided in the terminal portion (170) of the battery cell (100) may include a terminal rivet (180) and a terminal plate (190), and may be a positive terminal and a negative terminal having different polarities, and the terminal portions (170) of adjacent battery cells (100) may be electrically connected in series or in parallel by a bus bar (200) described below. Meanwhile, while the above description exemplifies a serial connection, it is not limited to this structure and various connection structures may be employed as needed. Furthermore, the number and arrangement of battery cells (100) are not limited to the structure illustrated in FIG. 1 and may be changed as needed.

[0063] A plurality of battery cells (100) can be arranged in one direction so that the wide surfaces of the battery cells (100) face each other, and the arranged plurality of battery cells (100) can be fixed by a housing.

[0064] The connection between the terminal portion (170) and the bus bar (200) can be performed by any one of soldering, resistance welding, laser welding, or projection welding methods.

[0065] In a state where the bus bar (200) is installed facing the terminal portion (170) of the battery cell (100), the bus bar (200) is fixed to the terminal portion (170) by welding. A welding fixing portion (300) is formed by a welding seam generated during the welding operation, and this welding fixing portion (300) is a conductor that is connected to the bus bar (200) and the terminal portion (170), respectively. Since a space is provided between the bus bar (200) and the terminal portion (170), the gas generated when the welding fixing portion (300) is formed by the welding operation can be discharged to the outside of the terminal portion (170) through the space formed between the terminal portion (170) and the bus bar (200).

[0066] A battery module (1) according to one embodiment of the present invention may include a battery cell (100), a bus bar (200), and a welding fixing part (300). When laser welding is performed to fix the bus bar (200) to the terminal part (170), the generated melting pool is cooled to form the welding fixing part (300). If there are many pores on the inside of the welding fixing part (300), the welding area may be reduced, which may lower the strength of the welding fixing part (300). Therefore, the present invention provides a passage for discharging gas between the bus bar (200) where the welding fixing part (300) is formed and the terminal part (170), thereby reducing or preventing the formation of pores within the welding fixing part (300). Accordingly, the cross-sectional area of ​​the welding fixing part (300) may be increased, which may improve the strength of the welding fixing part (300).

[0067] The directions used in the present invention are defined. The width direction and the first direction are defined as the x-axis direction, the length direction and the second direction are defined as the y-axis direction, and the up-down direction and the third direction are defined as the z-axis direction.

[0068] FIG. 3 is a perspective view illustrating a battery cell (100) according to one embodiment of the present invention, and FIG. 4 is a cross-sectional view of a battery cell (100) according to one embodiment of the present invention. As illustrated in FIGS. 3 and 4, the battery cell (100) includes an electrode assembly (110), a housing (120), a current collector (160), and a terminal portion (170).

[0069] The electrode assembly (110) may be formed by winding or stacking a laminate of a first electrode plate, a separator, and a second electrode plate formed in a thin plate shape or a film shape. When the electrode assembly (110) is a rolled laminate, the winding axis may be parallel to the width direction (x) of the housing (120). In addition, the electrode assembly (110) may be a stack type rather than a rolled type, and the shape of the electrode assembly (110) is not limited in the present invention. In addition, the electrode assembly (110) may be a Z-stack electrode assembly (110) in which a positive electrode plate and a negative electrode plate are inserted on both sides of a separator folded in a Z-stack shape. In addition, the electrode assembly (110) may be housed inside the housing (120) by stacking one or more electrode assemblies (110) such that their long sides are adjacent to each other, and the number of electrode assemblies (110) is not limited in the present invention. The first electrode plate of the electrode assembly (110) can serve as a cathode, and the second electrode plate can serve as an anode. Of course, the opposite is also possible.

[0070] The first electrode tab of the first electrode plate and the second electrode tab of the second electrode plate are respectively positioned at both ends of the electrode assembly (110) as described above. In some examples, the electrode assembly (110) may be accommodated in a housing (120) together with an electrolyte. In addition, the electrode assembly (110) is electrically connected by welding a current collector (160) to the first electrode tab of the first electrode plate and the second electrode tab of the second electrode plate, which are exposed on both sides.

[0071] The housing (120) can be modified in various ways within the technical concept of accommodating the electrode assembly (110). According to one embodiment of the present invention, the housing (120) includes a case (130) and a cap assembly (150).

[0072] The case (130) may be in the shape of a roughly rectangular parallelepiped with an opening formed at the top and a hollow interior. Through this opening, the electrode assembly (110) may be inserted into the interior of the case (130). In addition, a current collector (160) that electrically connects the electrode assembly (110) and the terminal portion (170) may also be located within the case (130). The case (130) may include a rectangular bottom surface and four side surfaces extending approximately vertically from the four sides of the bottom surface.

[0073] A cap assembly (150) may be coupled to a case (130). In some examples, the cap assembly (150) may include a cap plate (151), a seal gasket (152), a stopper (153), a safety vent (154), and an insulating member (156).

[0074] The cap plate (151) seals the opening of the case (130) and may be formed of the same material as the case (130). For example, but not limited to, the cap plate (151) may be joined to the case (130) by a laser welding method. Here, since the cap plate (151) may have the same polarity as one side of the terminal portion (170) as described above, the cap plate (151) and the case (130) may have the same polarity. The cap plate (151) may be provided with an electrolyte injection port (151a) and a vent hole (151b) penetrating between the upper surface and the lower surface.

[0075] A seal gasket (152) is made of an insulating material and is installed between a cap plate (151) and a terminal plate (190) provided in a terminal portion (170). The seal gasket (152) is installed in a space formed by a terminal rivet (180), a terminal plate (190), and a cap plate (151). Therefore, the seal gasket (152) seals between the terminal plate (190) and the cap plate (151), and also seals the perimeter of the terminal rivet (180). The seal gasket (152) prevents external moisture from penetrating into the interior of the battery cell (100) or prevents an electrolyte contained within the battery cell (100) from leaking out to the exterior. In addition, the seal gasket (152) may be formed of an insulating material having elasticity and may block the electrical connection between the terminal portion (170) and the cap plate (151).

[0076] The plug (153) can seal the electrolyte injection port (151a) after the electrolyte is injected into the interior of the housing (120) through the electrolyte injection port (151a) of the cap plate (151).

[0077] The safety vent (154) is installed at a position facing the vent hole (151b) of the cap plate (151) and can be opened at a set pressure. The safety vent (154) is installed in the cap plate (151) and can close or open the vent hole (151b).

[0078] The insulating member (156) corresponds to the shape of the cap plate (151) and can be transformed into various shapes within the technical concept of being installed between the cap plate (151) and the electrode assembly (110). The insulating member (156) has a size that roughly corresponds to the lower surface of the cap plate (151) and can be installed in close contact with or spaced apart from the lower surface of the cap plate. Of course, holes can be formed in the insulating member (156) at positions corresponding to the electrolyte injection port (151a) and the vent hole (151b) formed in the cap plate (151). The insulating member (156) can prevent unnecessary short circuits from occurring between the current collector (160) and the cap plate (151).

[0079] In addition, the insulating member (156) is formed to have a size corresponding to that of the cap plate (151), thereby preventing unnecessary short circuits between the electrode assembly (110) and the cap plate (151). The insulating member (156) may be made of polyphenylene sulfide (PPS) having a melting point (285°C) and high tensile strength, thereby preventing heat from being transmitted to adjacent cells when heat from an internal short circuit caused by penetration of the secondary battery is released through the safety vent (154), thereby improving safety. Such an insulating member (156) can prevent heat from being transmitted to an adjacent battery cell (100) through the cap assembly (150). That is, when the battery cell (100) is composed of one unit cell, since blocking heat transmission to an adjacent secondary battery is not required, polypropylene (PP: Poly Propylene) can also be applied as the insulating material (156).

[0080] The current collector (160) may include a first current collector that is in contact with a first electrode tab protruding from one end of the electrode assembly (110), and a second current collector that is in contact with a second electrode tab protruding from the other end of the electrode assembly (110). The current collector (160) is installed in a curved shape on the inside of the housing (120) and electrically connects the electrode assembly (110) and the terminal rivet (180) of the terminal portion (170). The current collector (160) may be provided with a terminal hole, and the terminal rivet (180) may be inserted into the terminal hole and riveted and / or welded. In some examples, the first current collector may be made of copper or a copper alloy, and the second current collector may be made of, for example, but not limited to, aluminum or an aluminum alloy.

[0081] FIG. 5 is a perspective view illustrating a bus bar (200) according to one embodiment of the present invention, and FIG. 6 is a cross-sectional view illustrating a state in which a bus bar (200) according to one embodiment of the present invention is fixed to a terminal portion (170). As illustrated in FIGS. 5 and 6, the terminal portion (170) can be variously modified within the technical concept of being electrically connected to the electrode assembly (110). The terminal portion (170) is electrically connected to the electrode assembly (110) and protrudes outward from the housing (120) to face the bus bar (200). The terminal portion (170) can be electrically connected to the bus bar (200) through the welding fixing portion (300). In addition, since the terminal portion (170) and the bus bar (200) are installed in contact with each other, they can be electrically connected. The terminal portion (170) according to one embodiment of the present invention can include a terminal rivet (180) and a terminal plate (190). The terminal rivet (180) and the terminal plate (190) can be electrically connected. The terminal portion (170) can be divided into a positive pole and a negative pole according to the polarity connected to the electrode assembly (110).

[0082] The terminal part (170) is connected to the housing (120), and various modifications are possible within the technical concept of having a guide part (196, 197) that guides the gas generated during welding of the terminal part (170) and the bus bar (170) to be discharged to the outside of the terminal part (170).

[0083] The terminal rivet (180) is electrically connected to the electrode assembly (110), and one side is located on the inside of the housing (120) of the battery cell (100) and the other side is located on the outside of the housing (120). The terminal rivet (180) is installed on the cap plate (151), and various modifications are possible within the technical concept of being connected to the terminal portion (170). The terminal rivet (180) extends in the vertical direction (z), and the lower side of the terminal rivet (180) is in contact with the current collector (160), so that current is transmitted through the current collector (160). The terminal rivet (180) is fixed in a state of being inserted into the connection hole (193) provided in the terminal plate (190), so that it is electrically connected to the terminal plate (190).

[0084] A terminal rivet (180) according to one embodiment of the present invention includes a rivet head (181), a rivet body (184), and a rivet tail (187). A concave first rivet groove (182) is formed on the upper end of the rivet head (181). A protrusion protruding outward is provided on the edge of the rivet head (181), and since it catches on a step provided in a connecting hole (193) of a terminal plate (190), the terminal rivet (180) can be prevented from being separated from the lower side of the terminal plate (190).

[0085] The rivet body (184) extends downward from the rivet head (181) and is located inside the connecting hole (193) of the terminal plate (190) together with the rivet head (181). A catch (185) protruding horizontally from the rivet body (184) catches on a lower groove (192) provided in the terminal plate (190), thereby restricting the vertical (z) and horizontal movement of the terminal rivet (180).

[0086] The rivet tail (187) extends downward from the rivet body (184) and is fixed in contact with the current collector (160). A second rivet groove (188) having a concave groove shape may be formed at the lower end of the rivet tail (187). Since the rivet tail (187) is fixed in contact with the current collector (160) electrically connected to the electrode assembly (110), it has the same polarity as the current collector (160).

[0087] FIG. 7 is a perspective view illustrating a battery cell having a terminal portion (170) according to one embodiment of the present invention, and FIG. 8 is a perspective view illustrating a terminal portion (170) according to one embodiment of the present invention. As illustrated in FIGS. 7 and 8, the terminal plate (190) is located on the outside of the cap plate (151) provided in the housing (120). The terminal plate (190) can be electrically connected to the terminal rivet (180). Since the terminal plate (190) has a region in contact with the bus bar (200) and a region spaced apart from the bus bar (200), when the welding fixing portion (300) is created by a welding operation, gas inside the welding fixing portion (300) can be discharged to the outside of the terminal plate (190) through the space where the terminal plate (190) and the bus bar (200) are spaced apart. A terminal plate (190) according to one embodiment of the present invention includes a plate body (191), a connection hole portion (193), a first guide portion (196), a second guide portion (197), and a terminal upper surface (199).

[0088] The plate body (191) is located on the outside of the cap plate (151) provided in the housing (120), and various modifications are possible within the technical concept of being electrically connected to the terminal rivet (180). The plate body (191) is located on the upper side of the cap plate (151), and a seal gasket (152) may be installed between the plate body (191) and the cap plate (151) to achieve insulation. The plate body (191) may have a square plate shape, and a lower groove (192) is formed on the lower surface of the plate body (191) for inserting a catch (185) of the terminal rivet (180).

[0089] The connecting hole (193) can be modified in various ways within the technical concept of forming a hole in the plate body (191) in the vertical direction so that the terminal rivet (180) can be positioned. The connecting hole (193) according to one embodiment of the present invention may include a first connecting hole (194) that forms a hole for positioning the rivet body (184), and a second connecting hole (195) that is positioned above the first connecting hole (194) and has a protrusion provided on the outside of the rivet head (181). The first connecting hole (194) may be in communication with the lower groove (192). The diameter of the first connecting hole (194) may be formed smaller than the diameter of the second connecting hole (195).

[0090] The guide portion provided in the terminal portion (170) of the battery cell (100) to guide gas discharge may include a first guide portion (196) and a second guide portion (197).

[0091] The first guide part (196) can be modified in various ways within the technical concept of forming a groove on the outside of the connection hole part (193) along the position where the welding fixing part (300) is formed. The first guide part (196) according to one embodiment of the present invention can form a groove that extends in a ring shape along the outer circumference of the connection hole part (193). The first guide part (196) and the bus bar (200) can be spaced apart at a set interval. The interval between the first guide part (196) and the bus bar (200) according to one embodiment of the present invention can be 0.1 to 0.4 mm. When the interval between the first guide part (196) and the bus bar (200) is less than 0.1 mm, there is a problem in that the gas discharged to the outside of the welding fixing part (300) does not smoothly move between the first guide part (196) and the bus bar (200). In addition, if the gap between the first guide part (196) and the bus bar (200) exceeds 0.4 mm, the outer shape of the terminal part (170) may increase, causing interference with other parts.

[0092] Fig. 9 is a perspective view showing a position where a welding fixing part (300) is installed in a terminal part (170) according to one embodiment of the present invention, and Fig. 10 is a plan view showing a terminal part (170) according to one embodiment of the present invention. As shown in Figs. 9 and 10, the second guide part (197) can be variously modified within the technical concept of forming a groove connecting the first guide part (196) and the outside of the plate body (191). The second guide part (197) forms a groove on the terminal upper surface (199) to be described later and is in communication with the second guide part (197). The second guide part (197) is provided in plurality.

[0093] The gas generated when creating the welding fixture (300) can be easily and quickly discharged to the outside of the terminal plate (190) along the second guide portion (197) after moving along the first guide portion (196). For example, the second guide portion (197) can be installed in a cross shape centered on the connection hole portion (193).

[0094] A terminal rivet (180) is installed at the center of the terminal plate (190), a first guide portion (196) is positioned on the outer periphery of the terminal rivet (180), and a welding fixing portion (300) is positioned circumferentially on the inner side of the first guide portion (196). A second guide portion (197) forming a groove portion connected to the first guide portion (196) can form a cross-shaped groove centered on the terminal rivet (180).

[0095] The terminal upper surface (199) protrudes from the plate body (191) toward the bus bar (200) and is electrically connected to the bus bar (200), and can be modified in various ways within the technical concept. The terminal upper surface (199) according to one embodiment of the present invention is located on the outside of the first guide part (196) and can be located above the first guide part (196) in a planar shape protruding upward. Accordingly, if the thickness between the terminal upper surface (199) and the lower surface of the plate body (191) is T1, and the thickness between the first guide part (196) and the lower surface of the plate body (191) is T2, T1 has a larger value than T2.

[0096] As illustrated in FIGS. 5 and 6, the bus bar (200) can be modified in various ways within the technical concept of being electrically connected to the battery cell (100). The bus bar (200) according to one embodiment of the present invention includes a first connecting plate (210), a second connecting plate (220), and a curved connecting portion (230).

[0097] The first connecting plate (210) is in contact with the terminal portion (170) and is capable of various modifications within the technical concept of being electrically connected. The second connecting plate (220) is installed spaced apart from the first connecting plate (210) and is capable of various modifications within the technical concept of being electrically connected within the technical concept of being in contact with the adjacent terminal portion (170).

[0098] According to one embodiment of the present invention, the first connecting plate (210) and the second connecting plate (220) are positioned on the upper side of the terminal plate (190) and are fixed in contact with the terminal plate (190) through a welding fixing member (300). In addition, the first connecting plate (210) and the second connecting plate (220) may have a square plate shape.

[0099] The curved connecting portion (230) connects the first connecting plate (210) and the second connecting plate (220) and can be modified in various ways within the technical concept of forming a curved surface. Since the curved connecting portion (230) according to one embodiment of the present invention is a plate bent into a curved shape, even if the distance of the terminal portion (170) connected by the bus bar (200) changes, the connection between the bus bar (200) and the terminal portion (170) can be stably formed as the curved connecting portion (230) bends or unfolds.

[0100] The welding fixing member (300) can be modified in various ways within the technical concept of fixing the bus bar (200) to the terminal portion (170) of the battery cell (100) by welding. The welding fixing member (300) is a welding seam created by a welding operation that fixes the bus bar (200) to the terminal plate (190), and can form a protrusion that extends from the bus bar (200) and is fixed to the first guide portion (196).

[0101] When the bus bar (200) is positioned on the upper side of the terminal plate (190), the bus bar (200) is in contact with the upper surface of the terminal. When laser welding is performed from the upper side of the bus bar (200) toward the first guide part (196) of the terminal plate (190), the welding seam extends to the lower side of the bus bar (200), partially melting and then solidifying the terminal plate (190) positioned on the first guide part (196). During the welding operation, the gas inside the welding fixing part (300) is discharged into the space formed by the first guide part (196), thereby preventing the formation of pores inside the welding fixing part (300).

[0102] The welding fixing member (300) can form a ring-shaped protrusion extending in the circumferential direction on the outside of the terminal rivet (180), and the upper side of the welding fixing member (300) is fixed to the bus bar (200) and the lower side is fixed to the terminal plate (190).

[0103] Fig. 11 is a plan view illustrating a terminal portion (170) according to another embodiment of the present invention. As illustrated in Fig. 11, the second guide portion (198) may be installed radially with the connection hole portion (193) as the center. The second guide portion (198), which is connected to the first guide portion (196), is installed radially with the terminal rivet (180) or the connection hole portion (193) as the center, and guides the gas discharged to the first guide portion (196) to the outside of the terminal plate (190).

[0104] As described above, a space for gas discharge is formed between the terminal portion (170) and the bus bar (200) to guide the discharge of gas generated during welding, so that the area to be welded by the welding fixing portion (300) from which the pores are discharged increases, thereby ensuring improved welding strength.

[0105] In addition, when a certain gap (0.1 to 0.4 mm) is maintained between the bus bar (200) and the terminal portion (170), the size of the welding fixing portion (300) can be increased by inducing the spread of the melt pool, and there is an effect of removing pores by inducing the discharge of gas trapped inside the welding fixing portion (300). In addition, when a certain gap is maintained between the bus bar (200) and the terminal portion (170), a higher strength can be maintained than when welding without a gap between the bus bar (200) and the terminal portion (170).

[0106] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

1. Electrode assembly; A case accommodating the above electrode assembly; A cap plate sealing the opening of the above case; and A battery cell including a terminal portion connected to the cap plate and having a guide portion for discharging gas generated during welding with the bus bar to the outside.

2. In paragraph 1, The terminal portion is installed on the cap plate and is connected to the terminal portion by a terminal rivet; and A battery cell comprising a terminal plate electrically connected to the terminal rivet and having a region in contact with the bus bar and a region spaced apart from the bus bar.

3. In paragraph 2, The terminal plate is a plate body located on the outside of the cap plate and electrically connected to the terminal rivet; A connecting hole portion forming a hole in the plate body in the upper and lower direction so that the terminal rivet is positioned; A first guide part forming a groove on the outside of the above connecting hole part; and A battery cell including a second guide portion forming a groove portion connecting the first guide portion and the outer side of the plate body.

4. In paragraph 3, A battery cell characterized in that the first guide portion forms a groove portion extending in a ring shape along the outer circumference of the connection hole portion.

5. In paragraph 3, A battery cell, characterized in that the gap between the first guide portion and the bus bar is 0.1 to 0.4 mm.

6. In paragraph 3, A battery cell characterized in that the second guide section is provided in multiple numbers.

7. In paragraph 3, A battery cell characterized in that the second guide portion is installed radially around the connection hole portion.

8. In paragraph 3, A battery cell characterized in that the second guide portion is installed in a cross shape centered on the connection hole portion.

9. In paragraph 3, A battery cell characterized in that the terminal plate further includes a terminal upper surface that protrudes from the plate body in a direction toward the bus bar and makes surface contact with the bus bar and is electrically connected thereto.

10. In paragraph 9, A battery cell characterized in that the terminal surface is located above the first guide portion.

11. A battery cell having a terminal portion electrically connected to an electrode assembly; A bus bar electrically connected to the terminal portion; and A welding fixing member for fixing the bus bar to the terminal part by welding is included; A battery module characterized in that the gas generated during the creation of the above welding fixing portion is discharged to the outside of the terminal portion through the space formed between the terminal portion and the bus bar.

12. In paragraph 11, The above bus bar comprises a first connecting plate that is in contact with the terminal portion and is electrically connected; A second connecting plate installed spaced apart from the first connecting plate and electrically connected to an adjacent terminal section; and A battery module including a curved connecting portion that connects the first connecting plate and the second connecting plate and forms a curved surface.

13. In paragraph 11, The terminal portion is installed on the cap plate and connected to the terminal portion by a terminal rivet; and A battery module comprising a terminal plate electrically connected to the terminal rivet and having an area in contact with the bus bar and an area spaced apart from the bus bar.

14. In paragraph 13, The terminal plate is a plate body located on the outside of the cap plate and electrically connected to the terminal rivet; A connecting hole portion forming a hole in the plate body in the upper and lower direction so that the terminal rivet is positioned; A first guide part forming a groove on the outside of the connecting hole part along the position where the welding fixing part is formed; and A battery module including a second guide portion forming a groove portion connecting the first guide portion and the outer side of the plate body.

15. In paragraph 14, A battery module characterized in that the gas generated during the creation of the above welding fixing part moves along the first guide part and is then discharged to the outside of the terminal plate along the second guide part.

16. In paragraph 14, A battery module characterized in that the first guide portion forms a groove portion extending in a ring shape along the outer circumference of the connecting hole portion.

17. In paragraph 14, A battery module characterized in that the welding fixing member is a welding seam created by a welding operation that fixes the bus bar to the terminal plate, and forms a protrusion that extends from the bus bar and is fixed to the first guide member.

18. In paragraph 14, A battery module characterized in that the terminal plate further includes a terminal upper surface that protrudes from the plate body in a direction toward the bus bar and makes surface contact with the bus bar and is electrically connected thereto.

19. In paragraph 14, A battery module, characterized in that the first guide portion and the bus bar are spaced apart at a set interval.

20. In paragraph 14, A battery module, characterized in that the gap between the first guide portion and the bus bar is 0.1 to 0.4 mm.

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