Secondary battery and battery module including same

Abstract

The present invention relates to a battery module in which terminals of two secondary batteries are directly connected by welding, so that the battery module does not require a separate component for electrical connection and can reduce electrical contact resistance. A battery module disclosed as one embodiment of the present invention comprises: a first secondary battery and a second secondary battery having the same structure as the first secondary battery, the first secondary battery comprising: an electrode assembly having a first electrode tab and a second electrode tab respectively exposed on both sides thereof; a case accommodating the electrode assembly and having two open sides; a first cover plate sealing one open side of the housing; a first terminal electrically connected to the first electrode tab and exposed to an outer side of the first cap plate; a second cover plate sealing the other open side of the housing; and a second terminal electrically connected to the second electrode tab and exposed to an outer side of the second cap plate, in which a first protruding portion protruding outward from the first terminal of the first secondary battery is coupled to a second recessed portion recessed in the second terminal of the second secondary battery and is connected in series with the second recessed portion by welding.

Description

Technical Field

[0001] Various embodiments of the present invention relate to a secondary battery and a battery module including the same. Background Art

[0002] Secondary batteries are energy storage systems that provide excellent energy density by converting electrical energy into chemical energy and storing the chemical energy. Compared with primary batteries, secondary batteries are designed to be rechargeable and are widely used to power IT devices such as smart phones, mobile phones, laptops, and tablet personal computers. Recently, interest in electric vehicles has increased to prevent environmental pollution, and accordingly, high-capacity secondary batteries are being adopted by electric vehicles. Such secondary batteries should have certain characteristics, such as high density, high power, and stability.

[0003] Secondary batteries can be made larger in size or longer in one direction for higher output, but there are limitations in increasing the size and length. For this reason, a bus bar should be additionally applied to connect the two secondary batteries, which can thus increase resistance and complicate the process.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not constitute prior art. Summary of the invention

[0005] Detailed description of the technical problem of the invention

[0006] The present invention provides a secondary battery and a battery module including the same, in which terminals of two secondary batteries are directly coupled by welding and the battery module therefore does not require a separate component for electrical connection and can reduce contact resistance.

[0007] In addition, the present invention provides a secondary battery and a battery module including the same, in which the displacement amount of contact resistance can be minimized by separating terminals of two secondary batteries from each other except for a region where the terminals are directly coupled by welding.

[0008] Solutions to technical problems

[0009] According to an embodiment of the present invention, a secondary battery and a battery module including the same may include a first secondary battery and a second secondary battery having the same structure as the first secondary battery, wherein the first secondary battery includes: an electrode assembly having a first electrode terminal tab and a second electrode terminal tab exposed on both sides thereof, respectively; a shell accommodating the electrode assembly and having two open sides; a first cover plate sealing one open side of the shell; a first terminal electrically connected to the first electrode terminal tab and exposed to the outside of the first cover plate; a second cover plate sealing the other open side of the shell; and a second terminal electrically connected to the second electrode terminal tab and exposed to the outside of the second cover plate, wherein a first protruding portion protruding outward from the first terminal of the first secondary battery is connected to a second concave portion recessed in the second terminal of the second secondary battery and is connected in series with the second concave portion by welding.

[0010] The first terminal may include: a first inner terminal plate located on the inner side of the first cover plate; a first outer terminal plate located on the outer side of the first cover plate and having a first protruding portion protruding outward and a first concave portion recessed in its outer surface; and a first terminal column riveted to the first inner terminal plate on the inner side of the first cover plate and passing through the first cover plate to be connected to the first outer terminal plate on the outer side of the first cover plate by riveting or welding.

[0011] The first outer terminal plate may be made of the same metal as the second terminal, and may be made of a different metal than the first inner terminal plate.

[0012] The first convex portion may be located at the center of the outer surface of the first outer terminal plate, and the first concave portion may be provided in a ring shape along an edge of the outer surface of the first outer terminal plate.

[0013] The second terminal may include: a second inner terminal plate located on the inner side of the second cover plate; a second outer terminal plate located on the outer side of the second cover plate and having a second recessed portion in the center of the recessed outer surface and a second protruding portion protruding outward in a ring shape along the edge of the outer surface; and a second terminal column riveted and / or welded to the second inner terminal plate on the inner side of the second cover plate and passing through the second cover plate to be connected to the second outer terminal plate on the outer side of the second cover plate by riveting or welding.

[0014] The second inner terminal plate, the second outer terminal plate, and the second terminal column may be made of the same metal.

[0015] The first convex portion of the first external terminal plate of the first secondary battery may contact the second concave portion of the second external terminal plate of the second secondary battery.

[0016] The first convex portion of the first external terminal plate of the first secondary battery and the second concave portion of the second external terminal plate of the second secondary battery may be spaced apart from each other.

[0017] The first outer terminal plate may include a first main body portion in a flat plate shape, a first protruding portion may extend along a first direction on one side of the first main body portion, the first direction being a longitudinal direction of the first cover plate, and a first recessed portion may extend along the first direction on the other side of an outer surface of the first main body portion.

[0018] The second terminal may include: a second inner terminal plate, located on the inner side of the second cover plate; a second outer terminal plate, located on the outer side of the second cover plate and having a second main body portion in the shape of a flat plate, a second recessed portion extending along a first direction in one side of an outer surface of the second main body portion, and a second protruding portion extending along the first direction on the other side of the outer surface of the second main body and protruding outward from the other side of the outer surface of the second main body portion; and a second terminal column, riveted and / or welded to the second inner terminal plate on the inner side of the second cover plate and passing through the second cover plate to be connected to the second outer terminal plate on the outer side of the second cover plate by riveting or welding.

[0019] The first body portion of the first external terminal plate of the first secondary battery may contact the second body portion of the second external terminal plate of the second secondary battery.

[0020] A first body portion of a first external terminal plate of a first secondary battery and a second body portion of a second external terminal plate of a second secondary battery may be spaced apart from each other.

[0021] The secondary battery may further include: a first current collector electrically connecting the first electrode tab and the first terminal to each other; and a second current collector electrically connecting the second electrode tab and the second terminal to each other.

[0022] Advantageous Effects of the Invention

[0023] According to an embodiment of the present invention, in a secondary battery and a battery module including the same, two secondary battery terminals are directly coupled by welding, and thus a separate component for electrical connection is not required, and electrical contact resistance can be reduced.

[0024] According to embodiments of the present invention, in a secondary battery and a battery module including the same, a displacement amount of contact resistance can be minimized by separating terminals of two secondary batteries from each other except for a region where the terminals are directly coupled by welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1a and Figure 1b 1 and 2 are perspective views and partially enlarged views of an exemplary battery module according to the present invention.

[0026] Figure 2a and Figure 2b For along Figure 1b An example of a cross-sectional view taken along line 2-2'.

[0027] Figure 3a to Figure 3c for Figure 1a and Figure 1b A perspective view, a cross-sectional view, and an exploded perspective view of a secondary battery in a battery module shown in FIG.

[0028] Figure 4a and Figure 4b for Figure 3a and Figure 3b FIG. 4 is an enlarged perspective view of a first external terminal plate and a second external terminal plate of a secondary battery shown in FIG.

[0029] Figure 5a and Figure 5b 1 and 2 are perspective views and partially enlarged views of an exemplary battery module according to the present invention.

[0030] Figure 6a and Figure 6b for Figure 5b An enlarged plan view of a portion of a battery module.

[0031] Figure 7a and Figure 7b for Figure 5a and Figure 5b A perspective view and a cross-sectional view of a secondary battery of a battery module shown in FIG.

[0032] Figure 8a and Figure 8b for Figure 7a and Figure 7b FIG. 4 is an enlarged perspective view of a first external terminal plate and a second external terminal plate of a secondary battery shown in FIG. DETAILED DESCRIPTION

[0033] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

[0034] The examples of the present invention are provided to explain the present invention more completely to those skilled in the art, and the following examples may be modified in various other forms, and the scope of the present invention is not limited to the following examples. Of course, these embodiments are provided so that the present disclosure will be thorough and complete, and the scope of the present invention will be fully conveyed to those skilled in the art.

[0035] In addition, in the accompanying drawings, for clarity of illustration, layer and area sizes may be enlarged, and the same reference numerals refer to the same elements throughout. As used herein, the term "and / or" includes any and all combinations of one or more related enumerated items. In addition, it will be understood that when element A is referred to as being "connected to" element B, element A may be directly connected to element B, or there may be an intervening element C between them so that element A and element B are indirectly connected to each other.

[0036] The terms used in this article are only used for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in this article, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. It will be further understood that the terms "comprise" and / or "comprising" when used in this specification indicate the presence of the described features, quantities, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, parts and / or groups thereof.

[0037] It will be understood that although the terms first, second, etc. may be used herein to describe various components, elements, regions, layers, and / or sections, these components, elements, regions, layers, and / or sections should not be limited by these terms. These terms are only used to distinguish one component, element, region, layer, and / or section from another. Thus, for example, the first component, first element, first region, first layer, and / or first section discussed below may be referred to as the second component, second element, second region, second layer, and / or second section without departing from the teachings of the present invention.

[0038] For ease of description, spatially relative terms, such as "below," "beneath," "below," "above," and "on," may be used herein to describe the relationship of one element or feature illustrated in the figures to another element or feature. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if an element or feature in a figure is flipped, an element described as being "below" or "beneath" another element or feature would be oriented "on" or "above" the other element or feature. Thus, the exemplary term "below" may encompass both above and below orientations.

[0039] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those having ordinary skill in the art to which the present invention pertains can easily carry out the present invention.

[0040] refer to Figure 1a and Figure 1b , showing a perspective view and a partially enlarged view of an exemplary battery module according to the present invention. Figure 2a and Figure 2b , showing that along Figure 1b The battery module 10 may have two secondary batteries 100 electrically connected to each other. Preferably, the battery module 10 may have two secondary batteries 100 connected in series. Here, the two secondary batteries 100 included in the battery module 10 may have the same structure.

[0041] refer to Figure 3a , showing a perspective view of the secondary battery 100, referring to Figure 3b, showing that along Figure 3a A cross-sectional view taken along line 3b-3b' of the secondary battery 200, and referring to Figure 3c , showing Figure 3a 1 is an exploded perspective view of a secondary battery 100. Figure 4a and Figure 4b , respectively showing enlarged perspective views of a first external terminal plate and a second external terminal plate of the secondary battery 100 .

[0042] Below, we will refer to Figure 1a , Figure 1b , Figure 2a Figure 2c Figure 3a to Figure 3c , Figure 4a and Figure 4b A battery module 10 of the present invention is described.

[0043] First, the secondary battery 100 may include an electrode assembly 110 , a first current collector 120 , a first terminal 130 , a second current collector 140 , a second terminal 150 , a case 160 , a first cap assembly 170 , and a second cap assembly 180 .

[0044] 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, the first electrode plate 111, the separator 113, and the second electrode plate 112 being formed in the shape of a thin plate or a film. When the electrode assembly 110 is a wound laminate, the winding axis may be parallel to the longitudinal direction of the housing 160 (the direction perpendicular to the longitudinal direction of the first cover assembly 170 and the second cover assembly 180). 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 invention. In addition, the electrode assembly 110 may be accommodated in the housing 160 by stacking one or more electrode assemblies 110 so that their long sides are adjacent to each other, and the number of electrode assemblies 110 is not limited in the present invention.

[0045] The first electrode plate 111 of the electrode assembly 110 may be used as a negative electrode, and the second electrode plate 112 may be used as a positive electrode. Of course, the reverse is also possible.

[0046] The first electrode plate 111 may be formed by applying a first electrode active material such as graphite or carbon on a first electrode current collector formed of a metal foil such as copper, copper alloy, nickel, or nickel alloy, and may include a first electrode tab 111a (or a first uncoated portion) to which the first electrode active material is not applied. The first electrode tab 111a may become a current path between the first electrode plate 111 and the first terminal 130.

[0047] In some examples, the first electrode tab 111a may be formed by pre-cutting the first electrode plate 110 so as to protrude from one side when manufacturing the first electrode plate 111, and may be integrally formed with the first electrode plate 111. In some examples, the first electrode plate 111 may have a first uncoated portion 111a of the first electrode plate 111 that protrudes further from one side than the separator 113 without being separately cut.

[0048] The first electrode tab 111 a , which is an uncoated portion of the first electrode plate 111 exposed on one side of the electrode assembly 110 , may be coupled to the first current collector 120 by welding, or the first terminal 130 may be directly coupled to the first electrode tab 111 a by welding.

[0049] 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 formed of a metal foil such as aluminum or an aluminum alloy, and may include a second electrode tab 112a (or a second uncoated portion) to which the second electrode active material is not applied. In some examples, the second electrode tab 112a may be formed by pre-cutting the second electrode plate 112 so as to protrude to the other side when manufacturing the second electrode plate 112, and may be formed integrally with the second electrode plate 112. In some examples, the second electrode plate 112 may have a first uncoated portion 112a of the second electrode plate 112, which protrudes further to the other side than the separator 113 without being cut separately. The second electrode tab 112a is an uncoated portion of the second electrode plate 112 exposed on the other side of the electrode assembly 110, which may be coupled to the second current collector 140 by welding, or the second terminal 150 may be directly coupled to the second electrode tab 112a by welding.

[0050] In some examples, the first electrode tab 111a may be located on the left short side surface of the electrode assembly 110, and the second electrode tab 112a may be located on the right short side surface of the electrode assembly 110. Here, left and right are for convenience in Figure 3a to Figure 3c The explanation will be made based on the secondary battery 100 shown in FIG. 1 , and when the secondary battery 200 is rotated left and right or up and down, the left and right positions may change. Figures 3a to 3c Various components are described based on the secondary battery 100 shown in FIG.

[0051] In some examples, the separator 113 is located between the first electrode plate 111 and the second electrode plate 112 to prevent electrical short circuits and allow lithium ions to move, and may be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene. In addition, the separator 113 may be replaced with an inorganic solid electrolyte such as a sulfide, oxide, or phosphate compound that does not require a liquid or gel electrolyte.

[0052] The first electrode tab 111a of the first electrode plate 111 and the second electrode tab 112a of the second electrode plate 112 are respectively located at both ends of the electrode assembly 110. In some examples, the electrode assembly 110 may be accommodated in the housing 160 together with the electrolyte. In some examples, the electrolyte may include an organic solvent such as EC, PC, DEC, EMC or DMC, and a lithium salt such as LiPF6 or LiBF4. In addition, the electrolyte may be in a liquid phase, a solid phase or a gel phase. In some examples, when an inorganic solid electrolyte is used, the electrolyte may be omitted.

[0053] The first current collector 120 is formed of metal and may electrically connect the first electrode plate 111 and the first terminal 130 to each other. The first current collector 120 may be an easily bendable metal plate and have one side 121 that contacts the first electrode tab 111a of the electrode assembly 110 and is coupled to the first electrode tab 111a by welding, and the other side 122 that contacts the first terminal 130 and is coupled to the first terminal 130 by welding. The first current collector 120 may be made of copper or a copper alloy.

[0054] The first terminal 130 is formed of metal and may contact and be welded to the other side 122 of the first current collector 120 for electrical connection. In some examples, the first terminal 130 may include a first inner terminal plate 131 , a first terminal column 132 , and a first outer terminal plate 133 .

[0055] Here, the first inner terminal plate 131 may be located on the inner side of the first cover plate 171, and the first outer terminal plate 133 may be located on the outer side of the first cover plate 171. In addition, the first terminal column 132 may pass through the first cover plate 171 to be coupled with the first outer terminal plate 133 on the outer side of the first cover plate 171, and may be coupled with the first inner terminal plate 131 on the inner side of the first cover plate 171.

[0056] In addition, the first inner insulating member 172 may be further interposed between the first inner terminal plate 131 and the first cap plate 171, and the first outer insulating member 174 may be further interposed between the first outer terminal plate 133 and the first cap plate 171. In addition, the first sealing gasket 173 may be further interposed between the first terminal column 132 and the first cap plate 171, thereby sealing the first terminal 130 and the first cap plate 171 from each other.

[0057] First, the first inner terminal plate 131 may be in contact with the other side 122 of the first current collector 120 on one side located on the right side and coupled to the other side 122 of the first current collector 120. The first inner terminal plate 131 may be provided with a terminal hole 131a passing through between one side and the other side. Of course, the terminal hole 131a may be formed to correspond to the diameter of the first terminal column 132. The terminal hole 131a may be located approximately at the center of the first inner terminal plate 131.

[0058] The first terminal column 132 may be assembled and coupled to the terminal hole 131a of the first inner terminal plate 131. For example, the first terminal column 132 may be riveted and fixed on one side in a state of being assembled in the terminal hole 131a of the first inner terminal plate 131. The first current collector 120 may be coupled to the first inner terminal plate 131 by welding to one side of the first terminal column 132. The first inner terminal plate 131 may be made of the same metal as the first current collector 120, such as copper or a copper alloy. The first inner terminal plate 131 is made of the same metal as the first current collector 120, and thus can be easily welded to the first current collector 120.

[0059] The first terminal column 132 may be column-shaped and may protrude and extend to the outside of the first cover plate 171. In addition, a flange 132a may be formed on the outside of the first cover plate 171 to prevent the first terminal column 132 from being separated from the first cover plate 171. With respect to the first cover plate 171, the first terminal column 132 may be inserted from the outside and coupled to the terminal hole 133a of the first outer terminal plate 133, and may be inserted from the inside and coupled to the terminal hole 131a of the first inner terminal plate 131. Here, the flange 132a may be located between the first outer terminal plate 133 and the first cover plate 171.

[0060] The first outer terminal plate 133 may be provided with a terminal hole 133a that passes through between one surface and the other surface. Here, the terminal hole 133a may be located approximately at the center of the first outer terminal plate 133. Here, the first outer terminal plate 133 may include a first protruding portion 133x, the center of the outer surface in the first protruding portion 133x protrudes outward, and the inner surface may be flat. Here, the inner surface may be a surface facing the first cover plate 171, and may be a surface in contact with the first outer insulating member 174 inserted between the first cover plate 171 and the first outer terminal plate 133. In addition, the outer surface may be a surface opposite to the inner surface and facing the outside of the secondary battery 100.

[0061] Since the first protruding portion 133x is provided at the center, the first outer terminal plate 133 may have an edge that is relatively recessed in the direction of the first cover plate 171. Here, in the first outer terminal plate 133, a portion that is recessed in the inner surface direction compared to the first protruding portion 133x may be referred to as a first recessed portion 133y. The first recessed portion 133y may be provided in the shape of a square ring along an edge on the outer surface of the first outer terminal plate 133. Here, a height difference between the first protruding portion 133x and the first recessed portion 133y may be a first height (a).

[0062] The first outer terminal plate 133 may be provided with a terminal hole 133a approximately at the center of the first protruding portion 133x. The outer extension portion of the first terminal column 132 may be assembled and connected to the terminal hole 133a of the first outer terminal plate 133. For example, the first terminal column 132 may be fixed by riveting and / or welding in a state where it is assembled into the terminal hole 133a of the first outer terminal plate 133 from the outer surface located on the left side. The first outer terminal plate 133 has one side located on the right side and may face the outer surface of the first cover plate 171. Of course, an outer insulating member 174 made of an insulating material may be inserted between one side of the first outer terminal plate 133 and the outer surface of the first cover plate 171 for insulation.

[0063] In the first terminal 130, the first outer terminal plate 133 may be made of the same metal as the second terminal 150. The second outer terminal plate 133 may be made of aluminum or an aluminum alloy. In addition, the first terminal column 132 may be made of the same metal as the first outer terminal plate 133. That is, in the first terminal 130, the first inner terminal plate 131 and the first terminal column 132 are made of different metals, but may be coupled by riveting. The first terminal 130 may have the first outer terminal plate 133 and the first terminal column 132 exposed to the outside of the first cover plate 171 and protruding from the outside of the first cover plate 171. In addition, the first inner terminal plate 131 may be electrically connected to the first current collector 120 on the inner side of the first cover plate 171. .

[0064] Here, one side of the first inner terminal plate 131 may face the left short side of the electrode assembly 110. Of course, the first current collector 120 may be interposed between one side of the first inner terminal plate 131 and the left short side of the electrode assembly 110 so that the first terminal 130 and the first electrode tab 111a of the electrode assembly 110 may be electrically connected to each other.

[0065] The second current collector 160 is formed of metal, and may electrically connect the second electrode plate 112 and the second terminal 150 to each other. The second current collector 160 may be a metal plate that is easily bent, and has one side that contacts the second electrode tab 112a of the electrode assembly 110 and is coupled to the second electrode tab 112a by welding, and the other side that contacts the second terminal 150 and is coupled to the second terminal 150 by welding. In addition, the second current collector 160 may be coupled to the electrode assembly 110 and the second terminal 150 in a symmetrical form with respect to the first current collector 130 on the basis of the electrode assembly 110. In addition, the second current collector 160 may be made of aluminum or an aluminum alloy.

[0066] The second terminal 150 is formed of metal and may be electrically connected to the second current collector 160. In some examples, the second terminal 150 may include a second inner terminal plate 151, a second terminal column 152, and a second outer terminal plate 153.

[0067] Here, the second inner terminal plate 151 may be located on the inner side of the second cover plate 181, and the second outer terminal plate 153 may be located on the outer side of the second cover plate 181. Of course, the first inner insulating member 182 may be further inserted between the second inner terminal plate 151 and the second cover plate 181. The second outer insulating member 184 may be further inserted between the second outer terminal plate 153 and the second cover plate 181. In addition, the second sealing gasket 183 may be further inserted between the second terminal column 152 and the second cover plate 181. In addition, the second terminal column 152 may pass through the second cover plate 181 to be coupled with the second outer terminal plate 153 on the outer side of the second cover plate 181, and may be coupled with the second inner terminal plate 151 on the inner side of the second cover plate 181.

[0068] The second terminal 150 may be similar to the first terminal 130 in terms of shape and structure. However, the shape of the outer surface of the second outer terminal plate 153 of the second terminal 150 may be different from the outer surface of the first outer terminal plate 133 of the first terminal 130. The second outer terminal plate 153 may have an outer surface shaped to correspond to the outer surface of the first outer terminal plate 133. The second outer terminal plate 153 may include a second concave portion 153x that is laterally concave in the center of the outer surface. Since the second concave portion 153x is provided at the center, the second outer terminal plate 153 may have an edge that protrudes relatively outward. Here, in the second outer terminal plate 153, the portion that protrudes outward from the edge compared to the second concave portion 153x may be referred to as a second protruding portion 153y.

[0069] Here, the second protruding portion 153y may correspond to the shape of the first concave portion 133y of the first inner terminal plate 131, and the second concave portion 153x may correspond to the shape of the first protruding portion 133x of the first inner terminal plate 131. The second protruding portion 153y may protrude outward from the outer surface of the second outer terminal plate 153 in the shape of a square ring along the edge. Here, the height difference between the second concave portion 153x and the second protruding portion 153y may be a second height difference (y).

[0070] The second outer terminal plate 153 may be provided with a terminal hole approximately at the center of the second concave portion 153 x . In addition, the outer extension portion of the second terminal column 152 may be fitted and coupled to the terminal hole of the second outer terminal plate 153 .

[0071] In addition, the second terminal 150 may be coupled to the electrode assembly 110 through the second current collector 140 in a symmetrical form with respect to the first terminal 130 on the basis of the electrode assembly 110. In addition, in the second terminal 150, the second inner terminal plate 151, the second terminal column 152, and the second outer terminal plate 153 may all be made of aluminum or an aluminum alloy. Therefore, the second terminal column 152 may be coupled to the second inner terminal plate 151 by riveting and / or welding, and may be coupled to the second outer terminal plate 153 by riveting and / or welding.

[0072] The case 160 has a substantially rectangular hollow with openings 161 and 162 formed on both sides, and the electrode assembly 110 combined with the first and second current collectors 130 and 160 may be inserted into the interior of the case 160 through the openings 161 , 162 .

[0073] The housing 160 may include a rectangular upper surface and a lower surface extending in the longitudinal direction of the housing, and two rectangular long side surfaces connecting the long sides of the upper surface and the bottom surface and extending in the longitudinal direction. The housing 160 may be formed as an integral part by the upper surface, the lower surface, and the two long side surfaces. The housing 160 may have an exhaust hole passing through the upper surface or the lower surface. The housing 160 may have a safety exhaust member 163 installed in the exhaust hole. In addition, the safety exhaust member 163 may have a cutout thinner than other areas and may be opened at a set pressure. .

[0074] The first cover assembly 170 may be coupled to the left opening 161 of the housing 160. In some examples, the first cover assembly 170 may include a first cover plate 171, a first inner insulating member 172, a first sealing gasket 173, a first outer insulating member 174, and a first insulating member 175. The first cover plate 171 may have a flat square plate shape and seal the left opening 161 of the housing 160. The first cover plate 171 may be provided with a terminal hole 171a passing through between the outer surface and the inner surface. The first terminal column 132 may pass through the first cover plate 171 to be coupled to the terminal hole 171a of the first cover plate 171. In addition, the first terminal column 132 may be coupled to the first outer terminal plate 133 on the outer side of the first cover plate 171, and may be coupled to the first inner terminal plate 131 on the inner side of the first cover plate 171. Here, the first inner terminal plate 131 and the right side of the first terminal column 132 may be located inside the housing 160.

[0075] The first inner insulating member 172 may be interposed between the inner surface of the first cap plate 171 and the first inner terminal plate 131. The first inner insulating member 172 may be in close contact with the inner surface of the first cap plate 171, and may also be in close contact with the first sealing gasket 173. The first inner insulating member 172 may be made of an insulating material, and may insulate the first cap plate 171 and the first inner terminal plate 131 from each other.

[0076] 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 column 132 to seal the first cap plate 171 and the first terminal column 132 from each other. That is, the first sealing gasket 173 may be inserted between the first cap plate 171 and the first terminal column 132. The first sealing gasket 173 prevents external moisture from penetrating into the interior of the secondary battery 100, or prevents the electrolyte contained in the inner side of the secondary battery 200 from leaking to the outside. The first sealing gasket 173 may have one side in contact with the first outer insulating member 174 and the other side in contact with the first inner insulating member 172.

[0077] In addition, the first outer insulating member 174 may be interposed between the outer surface of the first cover plate 171 and the first outer terminal plate 133. The first outer insulating member 174 may be in close contact with the first cover plate 171, and may also be in close contact with the flange 132a of the first terminal column 132. The first coupling member 172 may be made of an insulating material, and may insulate the first cover plate 171 and the first outer terminal plate 133 from each other.

[0078] That is, the first cap plate 171 may be electrically isolated from the first terminal 130 by the first inner insulating member 172 , the first sealing gasket 173 , and the first outer insulating member 174 .

[0079] In addition, the first insulating member 175 may be interposed between the first cap plate 171 and the electrode assembly 110. The first insulating member 175 may be made of an insulating material, may prevent movement of the electrode assembly 110, and may prevent one side of the electrode assembly 110 from electrically contacting the first cap plate 171.

[0080] In addition, after the electrode assembly 110 combined with the first current collector 120 is accommodated in the case 160, the first cap plate 171 combined with the first terminal 130 may seal the opening of the case 160. Of course, before the first cap plate 171 seals the case 160, the one side 121 of the first current collector 120 and the first inner terminal plate 131 of the first terminal 130 may be coupled to each other by welding.

[0081] The second cover assembly 180 may be coupled to the right opening 162 of the housing 160. In some examples, the second cover assembly 180 may include a second cover plate 181, a second inner insulating member 182, a second sealing gasket 183, a second outer insulating member 184, and a second insulating member 185. The second cover assembly 180 may be the same as the first cover assembly 170 in terms of shape and structure. In addition, the shape and structure in which the second cover assembly 180 and the second terminal 150 are coupled to each other may be the same as the morphology and structure in which the first cover assembly 170 and the first terminal 130 are coupled to each other. However, the coupling shape of the second cover assembly 180 and the second terminal 150 may be symmetrical to the coupling shape of the first cover assembly 170 and the first terminal 130 on the basis of the housing 160.

[0082] In the secondary battery 100, the first cap assembly 170 connected to the first terminal 130 can be connected to one open side of the shell 160, and the second cap assembly 180 connected to the second terminal 150 can be connected to the other open side of the shell 160, so that the first terminal 130 and the second terminal 150 are located on both sides relative to the shell 160.

[0083] In addition, in the secondary battery 100, the first external terminal plate 133 of the first terminal 130 and the second external terminal plate 153 of the second terminal 150 may be made of the same metal. In addition, the battery module 10 may have two secondary batteries 100 electrically connected in series. Here, the two secondary batteries 100 included in the battery module 10 may have the same structure. For convenience, the following description will be made assuming that one secondary battery in the battery module 10 is referred to as the first secondary battery 100 and the other secondary battery is referred to as the second secondary battery 100'.

[0084] In the battery module 10, in a state where the first protruding portion 133x of the first external terminal plate 133 of the first terminal 130 of the first secondary battery 100 is inserted into the second concave portion 153x' of the second external terminal plate 153' of the second terminal 150' of the second secondary battery 100', the first concave portion 133y of the first secondary battery 100 and the second protruding portion 153y' of the second second battery 100' may be coupled to each other by welding and electrically connected. That is, the first external terminal plate 133 of the first secondary battery 100 and the second external terminal plate 153' of the second second battery 100' may be coupled to each other by welding from one side of the second protruding portion 153y' of the second secondary battery 100 in a contact state. Here, the welding may be laser welding.

[0085] Here, the first height (a) is the height between the first convex portion 133x and the first concave portion 133y of the first external terminal plate 133 of the first secondary battery 100, which may be equal to or less than the second height (b), which is the height between the second concave portion 153x and the second convex portion 153y of the second external terminal plate 153' of the second secondary battery 100'.

[0086] For example, when the first height (a) is equal to the second height (b), Figure 2a , the first convex portion 133x of the first secondary battery 100 and the second concave portion 153x of the second secondary battery 100' may contact each other. As another example, when the first height (a) is less than the second height (b), the first convex portion 133x of the first secondary battery 100 and the second concave portion 153x of the second secondary battery 100' may be spaced apart from each other. When the first height (a) is less than the second height (b), a gap is formed between the first convex portion 133x of the first secondary battery 100 and the second concave portion 153x of the second secondary battery 100', and thus the displacement amount of the contact resistance may be minimized.

[0087] In the battery module 10, the first external terminal plate 133 and the second external terminal plate 153' may be macroscopically flat surfaces, but may be microscopically rough surfaces. Therefore, as the area where the first external terminal plate 133 and the second external terminal plate 153' are connected to each other by welding increases, the gap between the rough surfaces can be filled by welding, which can reduce electrical contact resistance. That is, in the battery module 10, because the first external terminal plate 133 and the second external terminal plate 153 of the two secondary batteries 100 and 100' are welded to each other along their edges, the welding area increase that can reduce contact resistance.

[0088] In addition, in the battery module 10, two secondary batteries 100 are connected in series, and the first terminal 130 and the second terminal 150 are provided on both sides, so when a plurality of battery modules 10 are combined in the form of a group, cooling members (not shown) can be respectively combined in the upper region and the lower region of the housing 160, thereby reducing the degradation of the battery module 10 and improving the cooling performance. As an example, in a state where a plurality of battery modules 10 are arranged so that the long side surfaces face each other, the first terminal and / or the second terminal of the battery pack exposed to both sides can be respectively electrically connected.

[0089] In addition, the battery module 10 is provided with the first terminal 130 and the second terminal 150 respectively on both sides, so when a plurality of battery modules 10 are combined in the form of a group, the charge / discharge current flows in two directions along each terminal, thereby improving degradation compared to the case where two terminals are provided on one side and the charge / discharge current flows through the two terminals on one side. In addition, when a plurality of battery modules 10 are combined in the form of a group, each terminal can be connected to each other in two directions, thereby improving space utilization.

[0090] refer to Figure 5a and Figure 5b , showing a perspective view and a partially enlarged view of an exemplary battery module according to the present invention. Figure 6a and Figure 6b , showing Figure 5b The battery module 20 may have two secondary batteries 200 connected in series. Here, the two secondary batteries 200 included in the battery module 20 may have the same structure. Figure 7a , showing a perspective view of a secondary battery 200, and referring to Figure 7b , showing that along Figure 7a A cross-sectional view of the secondary battery 100 taken along line 7b-7b'. Figure 8a and Figure 8b , respectively showing enlarged perspective views of a first external terminal plate and a second external terminal plate of a secondary battery 200.

[0091] In the following, reference will be made to Figure 5a , Figure 5b , Figure 6a , Figure 6b , Figure 7a , Figure 7b , Figure 8a and Figure 8b A battery module 20 of the present invention is described.

[0092] First, the secondary battery 200 may include an electrode assembly 110, a first current collector 120, a first terminal 230, a second current collector 140, a second terminal 250, a case 160, a first cap assembly 170, and a second cap assembly 180. In addition, the first terminal 230 may include a first inner terminal plate 131, a first terminal column 132, and a first outer terminal plate 233. In addition, the second terminal 250 may include a second inner terminal plate 151, a second terminal column 152, and a second outer terminal plate 253.

[0093] Figure 7a and Figure 7b The secondary battery 200 shown in FIG. 1 may be similar to the secondary battery 200 in terms of the electrode assembly 110, the first current collector 120, the second current collector 140, the case 160, the first cap assembly 170, and the second cap assembly 180. Figure 3a to Figure 3c The same as the secondary battery 100 shown in FIG. Figure 7a and Figure 7b The secondary battery 200 shown in FIG. 1 can be similar to the first inner terminal plate 131 and the first terminal column 132 of the first terminal 230 and the second inner terminal plate 151 and the second terminal column 152 of the second terminal 250. Figure 3a to Figure 3c The secondary battery 100 shown in FIG.

[0094] Therefore, the following description of the secondary battery 200 will focus on the first and second external terminal plates 233 and 253 that are different from the secondary battery 100 .

[0095] The first outer terminal plate 233 may include a first body portion 233 x having a plate shape, a first protruding portion 233 y protruding outward from an outer surface of the first body portion 233 , and a first concave portion 233 z concave inward from an outer surface of the first body portion 233 x .

[0096] Here, the first body part 233x may be in the shape of a plate having a flat outer surface and an inner surface. In addition, the first protruding portion 233y and the first concave portion 233z may be integrally formed with the first body part 233x, and the inner surface may be made of aluminum or an aluminum alloy, which is on the same plane as the inner surface of the first body part 233x.

[0097] The first protruding portion 233y may extend along a first direction (x) on one side of the outer surface of the first main body portion 233x, which is the longitudinal direction of the first cover plate 171. The first concave portion 233z may extend along the first direction (x) on the other side of the outer surface of the first main body portion 233x. That is, the first protruding portion 233y and the first concave portion 233z may be provided on the outer surface of the first main body portion 233x so as to be symmetrical in the first main body portion 233x. Here, the lengths of the first main body portion 233x, the first protruding portion 233y and the first concave portion 233z in the first direction (x) may be the same. Here, the height difference between the outer surface of the first main body portion 233x and the outer surface of the first protruding portion 233y may be a first convex height (a1), and the height difference between the outer surface of the first main body portion 233x and the outer surface of the first concave portion 233x may be a first concave height (b1).

[0098] Since the first convex portion 233 y is provided on one side of the outer surface and the first concave portion 233 z is provided on the other side, the first outer terminal plate 233 may have two stepped portions and may have a stepped shape.

[0099] The second outer terminal plate 253 may include a second body portion 253x, a second protruding portion 253y protruding outwardly from the outer surface of the second body portion 253x, and a second concave portion 253z concave inwardly from the outer surface of the second body portion 233x. The second outer terminal plate 253 may be the same as the first outer terminal plate 233 in terms of shape and structure. However, in the second outer terminal plate 153, the second concave portion 253z may be provided on the other side of the outer surface of the second body portion 253x, and the second protruding portion 253y may be provided on one side of the outer surface of the second body portion 253x. That is, the shape of the outer surface of the second outer terminal plate 253 may correspond to the outer surface of the first outer terminal plate 233. In addition, the second outer terminal plate 253 may be coupled to the second cap assembly 180 so as to be symmetrical with the first outer terminal plate 233 on the basis of the electrode assembly 110.

[0100] Here, the second convex portion 253 y may correspond to the shape of the first concave portion 133 z of the first inner terminal plate 131 , and the second concave portion 153 x may correspond to the shape of the first convex portion 133 y of the first inner terminal plate 131 .

[0101] Here, the height difference between the outer surface of the second body portion 253x and the outer surface of the second protruding portion 253y may be a second protruding height (a2), and the height difference between the outer surface of the second body portion 253x and the outer surface of the second concave portion 253x may be a second concave height (b2).

[0102] In the secondary battery 200, the first external terminal plate 233 of the first terminal 230 and the second external terminal plate 253 of the second terminal 250 may be made of the same metal. In addition, the battery module 20 may have two secondary batteries 200 electrically connected in series. Here, the two secondary batteries 200 included in the battery module 20 may have the same structure. For convenience, the following description will assume that one secondary battery in the battery module 20 is called the first secondary battery 200 and the other secondary battery is called the second secondary battery 200'.

[0103] Therefore, in the battery module 20 in which two secondary batteries 200 and 200' are connected in series, the first protruding portion 233y of the first external terminal plate 233 of the first terminal 230 of the first secondary battery 200 and the second concave portion 253z' of the second external terminal plate 253' of the second terminal 250' of the second secondary battery 200' can be connected in series by direct welding in a state of contacting and overlapping each other. In addition, the first concave portion 233z of the first external terminal plate 233 of the first terminal 230 of the first secondary battery 200 and the second protruding portion 253z' of the second external terminal plate 253' of the second terminal 250' of the second secondary battery 200' can be connected in series by direct welding in a state of contacting and overlapping each other. Here, the first external terminal plate 233 of the first secondary battery 200 and the second external terminal plate 253' of the second secondary battery 200' can be connected to each other by welding along the first direction (x) on one side and the other side. That is, the two secondary batteries 200 and 200' may be coupled to each other by being connected in series at the sides of the first and second protruding portions 233y and 253y' by welding along the first direction (x). Here, the welding may be laser welding.

[0104] Here, the first protrusion height (a1) is the height between the first protrusion portion 233y and the first body portion 233x of the first external terminal plate 233 of the first secondary battery 200, which may be equal to or greater than the second recess height (b2), which is the height between the second recess portion 253z and the second body portion 153x of the second external terminal plate 253' of the second secondary battery 200'. In addition, the second protrusion height (b1) is the height between the second recess portion 253z and the second body portion 153x of the second external terminal plate 253' of the second secondary battery 200', which may be equal to or greater than the first recess height (b1), which is the height between the first recess portion 233z and the first body portion 233x of the first external terminal plate 233 of the first secondary battery 200. In addition, the first recess height (b1) and the second recess height (b2) may be the same as each other, and the first protrusion height (a1) and the second protrusion height (a2) may be the same as each other.

[0105] For example, when the first protrusion height (a1) is equal to the second recess height (b2), and the second protrusion height (a2) is equal to the first recess height (b1), Figure 6a , the first body part 233x of the first secondary battery 200 and the second body part 253x of the second secondary battery 200' may contact each other. As another example, when the first protrusion height (a1) is greater than the second recess height (b2), and the second protrusion height (a2) is greater than the first recess height (b1), the first body part 233x of the first secondary battery 200 and the second body part 253x of the second secondary battery 200' may be spaced apart from each other. In this way, when the first protrusion height (a1) is greater than the second recess height (b2), and the second protrusion height (a2) is greater than the first recess height (b1), a gap may be formed between the first body part 233x of the first secondary battery 200 and the second body part 253x of the second secondary battery 200', so the displacement amount of the contact resistance may be minimized.

[0106] Although the foregoing embodiments are described as practicing the secondary battery and the battery module including the same according to the present invention, the present invention is not limited to the above embodiments, and there may be many changes within the spirit and scope of the present invention. Those skilled in the art will recognize that various modifications to the disclosed embodiments are within the technical scope of the present invention.

[0107] Industrial application range

[0108] Various embodiments of the present invention may be applied to a secondary battery and a battery module including the same.

Claims

1. A secondary battery, include: An electrode assembly having a first electrode terminal tab and a second electrode terminal tab exposed on both sides thereof, respectively; a housing accommodating the electrode assembly and having two open sides; a first cover plate sealing an open side of the housing; a first terminal electrically connected to the first electrode tab and exposed to an outer side of the first cap plate; a second cover plate, sealing the other open side of the housing; and a second terminal electrically connected to the second electrode tab and exposed to an outer side of the second cap plate, wherein a first protruding portion protruding outward from a first terminal of a first secondary battery is coupled to a second concave portion concave in a second terminal of a second secondary battery and is connected in series with the second concave portion by welding.

2. The secondary battery according to claim 1, wherein the first terminal include: a first inner terminal plate, located on the inner side of the first cover plate; a first outer terminal plate, located on the outer side of the first cover plate and having a first protruding portion protruding outward and a first concave portion concave in an outer surface thereof; as well as A first terminal column is riveted to the first inner terminal plate on the inner side of the first cover plate and passes through the first cover plate to be coupled to the first outer terminal plate on the outer side of the first cover plate by riveting or welding. 3 . The secondary battery according to claim 2 , wherein the first outer terminal plate is made of the same metal as the second terminal and is made of a different metal from the first inner terminal plate. 4 . The secondary battery according to claim 2 , wherein the first convex portion is located at a center of an outer surface of the first outer terminal plate, and the first concave portion is provided in a ring shape along an edge of the outer surface of the first outer terminal plate.

5. The secondary battery according to claim 4, wherein the second terminal include: a second inner terminal plate, located on the inner side of the second cover plate; a second outer terminal plate located on the outer side of the second cover plate and having a second concave portion concave in the center of the outer surface and a second convex portion convex outward in a ring shape along the edge of the outer surface; as well as A second terminal column is riveted and / or welded to the second inner terminal plate on the inner side of the second cover plate and passes through the second cover plate to be riveted or welded to the second outer terminal plate on the outer side of the second cover plate. 6 . The secondary battery according to claim 5 , wherein the second inner terminal plate, the second outer terminal plate, and the second terminal column are made of the same metal.

7. A secondary battery according to claim 2, wherein the first external terminal plate includes a first main body portion in a flat plate shape, the first protruding portion extends along a first direction on one side of the first main body portion, the first direction is a longitudinal direction of the first cover plate, and the first recessed portion extends along the first direction on the other side of the outer surface of the first main body portion.

8. The secondary battery according to claim 7, wherein the second terminal include: a second inner terminal plate, located on the inner side of the second cover plate; a second outer terminal plate, located on the outer side of the second cover plate, and having a second main body portion in a flat plate shape, a second concave portion extending along the first direction and recessed in one side of the outer surface of the second main body portion, and a second convex portion extending along the first direction and protruding outward from the other side of the outer surface of the second main body portion on the other side of the outer surface of the second main body portion; as well as A second terminal column is riveted and / or welded to the second inner terminal plate on the inner side of the second cover plate and passes through the second cover plate to be riveted or welded to the second outer terminal plate on the outer side of the second cover plate.

9. The secondary battery according to claim 1, further comprising include: a first current collector electrically connecting the first electrode tab and the first terminal to each other; as well as A second current collector electrically connects the second electrode tab and the second terminal to each other.

10. A battery module comprising a first secondary battery and a second secondary battery, wherein the first secondary battery has the same structure as the secondary battery according to any one of claims 1 to 6, in: The first terminal of the first secondary battery includes a first outer terminal plate exposed to the outside of the first cap plate; The second terminal of the second secondary battery includes a second outer terminal plate exposed to the outside of the second cap plate; and The first external terminal plate of the first secondary battery and the second external terminal plate of the second secondary battery are connected in series by welding in a state in which outer surfaces thereof are in contact with each other. 11 . The battery module according to claim 10 , wherein a first protruding portion protruding outward from a center of the first external terminal plate of the first secondary battery contacts a second concave portion concave in a center of the second external terminal plate of the second secondary battery. 12 . The battery module of claim 10 , wherein a first protruding portion protruding outward from a center of the first external terminal plate of the first secondary battery and a second concave portion concave in a center of the second external terminal plate of the second secondary battery are spaced apart from each other.

13. The battery module according to claim 10, in: The first external terminal plate of the first secondary battery includes a first main body portion in a flat plate shape, the first protruding portion extends along a first direction on one side of the first main body portion, the first direction being a longitudinal direction of the first cap plate, and the first concave portion extends along the first direction on the other side of an outer surface of the first main body portion; and The second external terminal plate of the second secondary battery has a second main body portion in the shape of a flat plate, a second recessed portion extending along the first direction in one side of the outer surface of the second main body portion, and a second protruding portion extending along the first direction on the other side of the outer surface of the second main body portion and protruding outward from the other side of the outer surface of the second main body portion. 14 . The battery module according to claim 13 , wherein the first body portion of the first external terminal plate of the first secondary battery contacts the second body portion of the second external terminal plate of the second secondary battery. 15 . The battery module of claim 13 , wherein the first body portion of the first external terminal plate of the first secondary battery and the second body portion of the second external terminal plate of the second secondary battery are spaced apart from each other.

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