Secondary battery with improved terminal structure

Abstract

The disclosed invention relates to a secondary battery in which a positive terminal and a negative terminal are arranged spaced apart from each other on the top surface of a hexahedral battery case, and in one example, the terminal structure includes a terminal body that encloses the positive terminal or the negative terminal so that it is not exposed and is connected to the top surface of the battery case and one or more surfaces adjacent to the top surface, and an extension terminal that is electrically connected to the positive terminal or the negative terminal and exposed on any one surface of the terminal body except the top surface, and a connection terminal that faces the thickness direction of the secondary battery is provided on the extension terminal.

Description

Technical Field

[0001] The present invention relates to a secondary battery, and more particularly, to a prismatic secondary battery having an improved terminal structure that can easily change the arrangement structure of the positive terminal and / or the negative terminal and facilitate electrical connection to a plurality of secondary batteries.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0071855 filed on June 14, 2022, and all of the contents disclosed in the document of the Korean patent application are incorporated herein by reference.

Background Art

[0003] Unlike a primary battery, a secondary battery is rechargeable and has been actively researched and developed in recent years due to its potential for miniaturization and high capacity. With the increasing development of technology and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in response to the contemporary demand for environmental protection, the demand for secondary batteries as an energy source has increased even more rapidly.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries according to the shape of the battery case. An electrode assembly mounted inside the battery case in a secondary battery is a power generation element capable of charge and discharge, which has a laminated structure of electrodes and a separator.

[0005] The electrode assembly can be roughly classified into a jellyroll type in which a separator is interposed between a sheet-shaped positive electrode and a negative electrode coated with an active material and wound, a stack type in which a large number of positive electrodes and negative electrodes are sequentially laminated with a separator interposed therebetween, and a stack-and-folding type in which a unit cell of the stack type is wound with a long separation film.

[0006] Looking at rectangular secondary batteries among various types of secondary batteries, in most cases, the positive electrode terminal and the negative electrode terminal of the rectangular secondary battery are arranged together on one surface, or one is arranged on each of the opposing two side surfaces. Such arrangements of the positive electrode terminal and the negative electrode terminal are determined by the design specifications of various devices equipped with the rectangular secondary battery, and it becomes laborious to separately design the arrangement structures of the positive electrode terminal and the negative electrode terminal each time according to such design specifications even with the same form factor.

[0007] Also, in order to configure a plurality of secondary batteries into modules or packs, a bus bar or the like for electrically connecting the secondary batteries is required. However, since the design of the bus bar is subordinate to the arrangement structure of the positive electrode terminal and the negative electrode terminal, the design of the bus bar also becomes complicated.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] An object of the present invention is to provide a new rectangular secondary battery capable of easily changing and manufacturing the arrangement structure of the positive electrode terminal and the negative electrode terminal provided in the rectangular secondary battery without separate design changes, and further, a new rectangular secondary battery capable of easily facilitating electrical connection to a plurality of secondary batteries.

[0010] However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those of ordinary skill in the art from the description of the invention described below.

Means for Solving the Problems

[0011] The present invention relates to a secondary battery in which a positive electrode terminal and a negative electrode terminal are arranged separately from each other on the upper surface of a hexahedral battery case. In one example, a terminal body that wraps around so that the positive electrode terminal or the negative electrode terminal is not exposed and is coupled to the upper surface of the battery case and one or more surfaces following the upper surface, and is electrically connected to the positive electrode terminal or the negative electrode terminal, and includes an extension terminal exposed on any one surface of the terminal body excluding the upper surface, and a connection terminal in the thickness direction of the secondary battery is provided on the extension terminal.

[0012] In one embodiment of the present invention, the extension wiring that electrically connects the extension terminal to the positive electrode terminal or the negative electrode terminal is not exposed outside the terminal body.

[0013] And the extension wiring that electrically connects the extension terminal to the positive electrode terminal or the negative electrode terminal can be insulated from the outside.

[0014] The terminal body is coupled to the upper surface of the battery case and one side surface following the upper surface, and the extension terminal is exposed on the one side surface.

[0015] And the terminal structure is coupled to the positive electrode terminal and the negative electrode terminal one by one.

[0016] In one embodiment of the present invention, the connection terminal extends in one direction or both directions along the thickness direction.

[0017] The connection terminal can be electrically connected to an extension terminal or a connection terminal of another adjacent secondary battery.

[0018] For example, a plurality of secondary batteries are aligned along the thickness direction, and the connection terminals provided in each secondary battery are connected in series or in parallel to the extension terminals or connection terminals of adjacent secondary batteries.

[0019] And the connection terminal can be integrally formed with the extension terminal.

[0020] On the other hand, in another embodiment of the present invention, an end portion of the connection terminal may form a slot that is open in the thickness direction.

[0021] In such an embodiment, a connection terminal of an adjacent secondary battery may be inserted into the slot of the connection terminal.

Effects of the Invention

[0022] The secondary battery of the present invention having the above-described configuration can easily change the arrangement structure of the positive terminal and / or the negative terminal by coupling the terminal structure to the upper surface corner portion of the secondary battery. Therefore, since the position of the terminal portion can be freely controlled without affecting the existing cell internal manufacturing process, it is possible to develop a square secondary battery and reduce the production cost.

[0023] Further, by providing a binding member in the terminal structure, when connecting a plurality of secondary batteries in series / parallel / series-parallel circuits along the thickness direction, it is possible to directly connect the terminal structures without a separate bus bar. As a result, the structure can be simplified during the manufacture of battery modules and packs, and the manufacturing cost can be reduced.

[0024] However, the technical effects that can be obtained by the present invention are not limited to the above-described effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention should not be construed as being limited only to the matters described in such drawings.

Brief Description of the Drawings

[0026]

Figure 1

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Mode for Carrying Out the Invention

[0027] Since the present invention can be subjected to various modifications and can have various embodiments, specific embodiments will be described in detail below.

[0028] However, this is not intended to limit the present invention to specific embodiments, and is understood to include all modifications, equivalents, or alternatives included in the spirit and technical scope of the present invention.

[0029] In the present invention, terms such as "including" and "having" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and do not preclude the presence or addition possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0030] In the present invention, when a part such as a layer, film, region, or plate is described as being "above" another part, this includes not only the case where it is directly above the other part but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only the case where it is directly below the other part but also the case where there is another part in between. Also, in the present application, being "disposed above" can include not only the upper part but also the case of being disposed below.

[0031] The present invention relates to a secondary battery, particularly a secondary battery in which a positive electrode terminal and a negative electrode terminal are arranged separately from each other on the upper surface of a hexahedral battery case.

[0032] In one example, the secondary battery according to the present invention has a terminal structure body coupled to at least one upper surface corner of the battery case. The terminal structure body includes a terminal main body that wraps so that the positive electrode terminal or the negative electrode terminal is not exposed and is coupled to the upper surface of the battery case and one or more surfaces following the upper surface, and an extension terminal that is electrically connected to the positive electrode terminal or the negative electrode terminal and is exposed on any one surface of the terminal main body excluding the upper surface.

[0033] Further, the terminal structure body is provided on the extension terminal and includes a connection terminal that faces in the thickness direction of the secondary battery. The connection terminal is an extended terminal that electrically connects the extension terminals of the terminal structure bodies provided in the secondary batteries aligned in the thickness direction, and a plurality of secondary batteries can be electrically connected by the connection terminal.

[0034] Thus, the secondary battery of the present invention including the terminal structure body can freely change the positions of the positive electrode terminal and the negative electrode terminal arranged on the upper surface of the battery case according to the user's requirements only by applying the terminal structure body without any separate design changes. Thereby, the production cost of the square secondary battery can be reduced.

[0035] In addition, by providing connection terminals to the terminal structure, when connecting a plurality of secondary batteries in a series / parallel / series-parallel circuit along the thickness direction, it is possible to directly connect the terminal structures without a separate bus bar. As a result, the structure can be simplified during the manufacture of battery modules and packs, and the manufacturing cost can be reduced.

[0036] Hereinafter, specific embodiments of the secondary battery according to the present invention will be described with reference to the accompanying drawings. The terms specifying relative positional relationships such as front, rear, left, right, up, and down used in the following description are based on the attached drawings unless otherwise defined.

[0037] (First Embodiment) FIG. 1 is a perspective view showing a secondary battery 100 according to the present invention, and FIG. 2 is a perspective view showing a coupling structure between the secondary battery 100 and a terminal structure 200 according to the present invention.

[0038] Referring to FIGS. 1 and 2, the present invention relates to a secondary battery 100, particularly a rectangular secondary battery 100 in which a positive electrode terminal 120 and a negative electrode terminal 130 are arranged separately from each other on the upper surface of a battery case 110 having a hexahedral shape. Here, the rectangular secondary battery 100 illustrated in the drawings is one example, and the ratios of the lateral width, longitudinal width, and height can be various. However, for convenience of explanation, the directions of front and rear, up and down, left and right are referred to based on the attached drawings. For example, the surface on which the positive electrode terminal 120 and the negative electrode terminal 130 are arranged is the upper surface, and the opposite surface is called the bottom surface.

[0039] The coordinate axes shown in FIGS. 1 and 2 specify the width direction W, thickness direction T, and height direction H of the secondary battery 100. The width direction W specifies the direction across the positive electrode terminal 120 and the negative electrode terminal 130, the thickness direction T specifies the depth direction (ground reference) perpendicular to the width direction W, and the height direction H specifies the direction perpendicular to both the width direction W and the thickness direction T.

[0040] The secondary battery 100 of the present invention includes a terminal structure 200. The terminal structure 200 is a hinge-like structure that is coupled to at least one upper surface corner of the battery case 110, and includes a terminal body 210 and an extension terminal 220.

[0041] The terminal body 210 refers to the main body of the terminal structure 200 that wraps around the positive terminal 120 or the negative terminal 130 so that they are not exposed to the outside and is coupled to the upper surface of the battery case 110 and one or more surfaces (such as side surfaces, front surfaces, rear surfaces, etc.) following the upper surface.

[0042] The extension terminal 220 is electrically connected to the positive terminal 120 or the negative terminal 130 and refers to the terminal of the terminal structure 200 that is exposed on any one surface of the terminal body 210 except the upper surface. That is, since the positive terminal 120 and the negative terminal 130 are wrapped by the terminal body 210 and not exposed, the extension terminal 220 functions as a new positive terminal 120 and negative terminal 130 located on one surface other than the upper surface.

[0043] Therefore, in the secondary battery 100 of the present invention, the positions of the positive terminal 120 and the negative terminal 130 arranged on the upper surface of the battery case 110 can be freely changed without any separate design changes only by applying the terminal structure 200. Thereby, in the present invention, for the rectangular secondary battery 100 with the same form factor, the positions of the positive terminal 120 and the negative terminal 130 can be easily changed using the terminal structure 200, and thereby, the production cost of the rectangular secondary battery 100 can be reduced.

[0044] And the terminal structure 200 includes a connection terminal 300 provided on the extension terminal 220. The connection terminal 300 extends in the thickness direction T of the secondary battery 100, and the connection terminal 300 means a secondary terminal or an extension terminal that is electrically connected to the extension terminal 220 or the connection terminal 300 of another adjacent secondary battery 100. The connection terminal 300 extends in the thickness direction T of the secondary battery 100, and a plurality of secondary batteries 100 aligned in the thickness direction T can be electrically connected by such connection terminals 300.

[0045] Thus, by providing the connection terminal 300 to the terminal structure 200, it becomes possible to directly connect the terminal structures 200 to each other. Therefore, a plurality of secondary batteries 100 can be electrically connected to each other by directly connecting them via the connection terminal 300 without a separate bus bar. As a result, the structure can be simplified and the manufacturing cost can be reduced when manufacturing a battery module or a pack.

[0046] In one embodiment of the present invention, the positive terminal 120 or the negative terminal 130 and the extension terminal 220 are electrically connected via the extension wiring 230, but the extension wiring 230 is not exposed outside the terminal body 210. And the extension wiring 230 is insulated from the outside. For example, the extension wiring 230 and the extension terminal 220 may be embedded in the terminal body 210 made of an insulating resin material by insert molding or the like. Thereby, only the extension terminal 220 is exposed to the outside, and problems such as damage to the extension wiring 230 or occurrence of a short circuit are prevented. For reference, the extension wiring 230 and the extension terminal 220 may be configured integrally or may be configured as separate parts and coupled to the terminal body 210.

[0047] According to the illustrated specific embodiment, the terminal body 210 is coupled to the upper surface of the battery case 110 and one side surface following the upper surface, and the extension terminal 220 is exposed on one side surface. Thereby, the positions of the positive terminal 120 and the negative terminal 130 located on the upper surface of the battery case 110 are moved to the side surface.

[0048] Also, the terminal structure 200 can be coupled to the positive terminal 120 and the negative terminal 130 one by one. Thereby, the positive terminal 120 and the negative terminal 130 are arranged one by one on the side surfaces facing each other. That is, the positive terminal 120 and the negative terminal 130 arranged together on the upper surface of the battery case 110 are moved to the adjacent side surfaces respectively. Thereby, the initial rectangular secondary battery 100 designed as a one-way secondary battery 100 is converted into a two-way secondary battery.

[0049] Then, the terminal structure 200 can be manufactured by attaching it additionally to the completed secondary battery 100 or, as shown in FIG. 2, by first coupling the terminal structure 200 to the cap plate 150 that constitutes the upper surface of the battery case 110 in the procedure of enclosing the electrode assembly 160 in the battery case 110.

[0050] FIG. 3 is a drawing illustrating various embodiments of the connection terminal 300, and three embodiments are exemplarily presented.

[0051] The connection terminal 300 is electrically connected to the extension terminal 220 of the terminal structure 200. For example, as shown in the drawing, the connection terminal 300 may be integrally formed with the extension terminal 220, or although not shown, a separately manufactured connection terminal 300 may be joined to the extension terminal 220.

[0052] The connection terminal 300 extends along the thickness direction T of the secondary battery 100, and may be a one - direction connection terminal 301 that extends only in one direction (+T direction or -T direction) of the thickness direction T as shown in FIGS. 3(a) and (b), or a two - direction connection terminal 302 that extends in both directions (+T direction and -T direction) as shown in FIG. 3(c).

[0053] And although it is difficult to uniformly define the extension length of the connection terminal 300, generally speaking, it can be said that it is necessary to have a length that can be stably joined to the extension terminal 220 or the connection terminal 300 on the terminal structure 200 of another secondary battery 100 that is directly adjacent to the secondary battery 100 in the thickness direction T.

[0054] As described above, the connection terminal 300 is for electrically connecting a plurality of secondary batteries 100 without a separate bus bar by being electrically connected to the extension terminal 220 or the connection terminal 300 of another secondary battery 100 adjacent in the thickness direction T. The various embodiments of the connection terminal 300 shown in FIG. 3 can be applied in various combinations for various electrical connections.

[0055] FIG. 4 is a drawing illustrating a structure in which two secondary batteries 100 are connected in parallel via connection terminals 300. The two secondary batteries 100 adjacent to each other in the thickness direction T are each provided with a terminal structure 200 at a positive electrode terminal 120 and a negative electrode terminal 130, and the two secondary batteries 100 are aligned such that the polarities of the terminals facing each other are the same.

[0056] In this way, a plurality of secondary batteries 100 aligned along the thickness direction T such that electrode terminals 120 or 130 of the same polarity face each other form a parallel circuit when adjacent terminal structures 200 are connected by connection terminals 300.

[0057] FIG. 4 illustrates an embodiment in which a one-way connection terminal 301 and an extension terminal 220 are connected to each other, and two secondary batteries 100 are illustrated. However, such a parallel connection can be continuously performed in the same pattern.

[0058] FIG. 5 is a drawing illustrating a structure in which three secondary batteries 100 are connected in series via connection terminals 300. Among the three secondary batteries 100 adjacent to each other in the thickness direction T, two secondary batteries 100 are each provided with a one-way connection terminal 301 at a positive electrode terminal 120 and a negative electrode terminal 130, and the three secondary batteries 100 are aligned such that the terminal polarities of the secondary batteries 100 facing each other are opposite.

[0059] Since the terminal polarities of the secondary batteries 100 facing each other are opposite, a series circuit is formed when adjacent terminal structures 200 are connected by connection terminals 300. However, as illustrated in FIG. 5, the connection of the connection terminals 300 must be performed only on one side of any of the opposing secondary batteries 100 and alternately while moving the secondary batteries 100 one by one.

[0060] In this way, by aligning a plurality of secondary batteries 100 in the thickness direction T and connecting the connection terminals 300 such that the polarities of the electrode terminals 120 and 130 conform to a desired circuit connection, the plurality of secondary batteries 100 can be electrically connected. For reference, it will be easily understood that a series-parallel circuit can be configured by combining the parallel connection in FIG. 4 and the series connection in FIG. 5.

[0061] (Second Embodiment) FIG. 6 is a drawing illustrating a connection terminal 300 according to the second embodiment of the present invention.

[0062] In the second embodiment of FIG. 6 as well, it is the same as the above-described first embodiment in that a plurality of secondary batteries 100 can be directly connected using the connection terminal 300 along the thickness direction T, but there is a difference in the structure for interconnecting the connection terminals 300.

[0063] In the first embodiment illustrated in FIGS. 1 to 5, the connection terminal 300 provided in the terminal structure 200 is extended to a length that can be joined to the extension terminal 220 or the connection terminal 300 on the terminal structure 200 of another secondary battery 100 that is directly adjacent in the thickness direction T, and does not include a special structure for joining the connection terminals 300.

[0064] On the other hand, in the second embodiment of FIG. 6, an end portion of a certain connection terminal 300 forms a slot 310 that is open in the thickness direction T, and correspondingly, the connection terminal 300 of another secondary battery 100 adjacent in the thickness direction T can be inserted into the slot 310.

[0065] FIG. 7 is a drawing exemplarily showing a structure in which a plurality of secondary batteries 100 are electrically connected using the connection terminal 300 of FIG. 6. Although three secondary batteries 100 are shown in FIG. 7, the terminal structure 200 of the secondary battery 100 located in the center is provided with a bidirectional connection terminal 302 corresponding to FIG. 3(c), and slots 310 are formed at both ends of the bidirectional connection terminal 302. Correspondingly, the secondary batteries 100 on both sides are provided with simple unidirectional connection terminals 301 without slots 310, and the two unidirectional connection terminals 301 are inserted into the slots 310 of the bidirectional connection terminal 302 respectively and interconnected.

[0066] Thus, according to the second embodiment of the present invention, since the connection terminals 300 of the terminal structure 200 form a slot structure for a plurality of secondary batteries 100, it becomes easy to mutually couple and electrically connect the connection terminals 300. That is, in the first embodiment, the electrical connection between the plurality of secondary batteries 100 is completed only with the joining between the connection terminals 300. However, according to the second embodiment, since the connection terminals 300 can be firmly contacted via the slot structure, the electrical connection is performed even in the assembled state.

[0067] Of course, also in the slot structure of the second embodiment, after connecting the connection terminals 300 to each other as a kind of provisional assembly state using the slots 310, a joining process such as welding can be performed in parallel to complete the connection more firmly.

[0068] The present invention has been described in more detail with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described in this specification are only one embodiment of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modifications that can replace them at the time of this application.

Explanation of Reference Numerals

[0069] 100: Secondary battery 110: Battery case 120: Positive terminal 130: Negative terminal 140: Bending part 150: Cap plate 160: Electrode assembly 200: Terminal structure 210: Terminal body 220: Extension terminal 230: Extension wiring 300: Connection terminal 301: Unidirectional connection terminal 302: Bidirectional connection terminal 310: Slot W: Width direction T: Thickness direction H: Height direction

Claims

1. A secondary battery in which a positive electrode terminal and a negative electrode terminal are arranged separately from each other on the upper surface of a hexahedral battery case; A terminal body that wraps around the upper surface of the battery case and one or more surfaces following the upper surface so that the positive electrode terminal or the negative electrode terminal is not exposed, and is connected to the positive electrode terminal or the negative electrode terminal. And an extension terminal exposed on any one surface other than the upper surface of the terminal body, and a terminal structure provided with a connection terminal directed in the thickness direction of the secondary battery on the extension terminal; A secondary battery including the above.

2. The secondary battery according to claim 1, wherein an extension wiring that electrically connects the extension terminal to the positive electrode terminal or the negative electrode terminal is not exposed outside the terminal body.

3. The secondary battery according to claim 1 or 2, wherein an extension wiring that electrically connects the extension terminal to the positive electrode terminal or the negative electrode terminal is insulated from the outside.

4. The terminal body is coupled to the upper surface of the battery case and one side surface following the upper surface, The secondary battery according to claim 1 or 2, wherein the extension terminal is exposed on the one side surface.

5. The secondary battery according to claim 4, wherein the terminal structure is coupled to each of the positive electrode terminal and the negative electrode terminal one by one.

6. The secondary battery according to claim 5, wherein the connection terminal extends in one direction or both directions along the thickness direction.

7. The connection terminal is Electrically connected to an extension terminal or a connection terminal of another adjacent secondary battery. The secondary battery according to claim 6.

8. A plurality of secondary batteries are aligned along the thickness direction, The secondary battery according to claim 7, wherein connection terminals provided in respective secondary batteries are connected in series or in parallel to extension terminals or connection terminals of adjacent secondary batteries.

9. The secondary battery according to claim 1 or 2, wherein the connection terminal is integrally formed with the extension terminal.

10. The secondary battery according to claim 7, wherein an end portion of the connection terminal forms a slot that is open in a thickness direction.

11. The secondary battery according to claim 10, wherein a connection terminal of a secondary battery adjacent to the slot of the connection terminal is inserted therein.

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