Secondary battery and secondary battery module

Abstract

This secondary battery comprises: an electrode assembly having a first main surface and a second main surface orthogonal to a first direction, which is the direction in which a positive electrode layer and a negative electrode layer overlap, and side surfaces extending in the first direction and connecting the first main surface and the second main surface; a first tape having first sections that cover part of the side surfaces of the electrode assembly, and second sections that cover part of the first main surface and part of the second main surface; an exterior body that encapsulates the electrode assembly; and a second tape that has third sections that cover part of the side surfaces of the electrode assembly via the exterior body, and fourth sections that cover part of the first main surface and part of the second main surface of the electrode assembly via the exterior body. When viewed in the first direction, the second section of the first tape and the fourth section of the second tape are separated from each other.

Description

Secondary battery and secondary battery module

[0001] The present disclosure relates to a secondary battery and a secondary battery module.

[0002] The following Patent Document 1 discloses a secondary battery having a structure in which an electrode assembly is enclosed in a pouch-shaped exterior body.

[0003] Japanese Patent Application Laid-Open No. 2007-258180

[0004] An object of the present disclosure is to provide a secondary battery and a secondary battery module with improved volumetric energy density.

[0005] A secondary battery according to one aspect of the present disclosure includes an electrode assembly including a positive electrode layer, a negative electrode layer overlapping the positive electrode layer, and a separator interposed between the positive electrode layer and the negative electrode layer, the electrode assembly having a first main surface and a second main surface extending in a second direction perpendicular to a first direction in which the positive electrode layer and the negative electrode layer overlap, and a side surface extending in the first direction and connecting the first main surface and the second main surface; a first portion covering a part of the side surface of the electrode assembly, and a second portion covering a part of the first main surface and a part of the second main surface, The electrode assembly includes a first tape integrally attached to the main surface, a pouch-shaped exterior body that encloses the electrode assembly, and a second tape attached to the exterior body and having a third portion that covers a portion of the side surface of the electrode assembly via the exterior body and a fourth portion that covers a portion of the first main surface and a portion of the second main surface of the electrode assembly via the exterior body, and integrally covers from the first main surface of the electrode assembly through the side surface to the second main surface via the exterior body, wherein the second portion of the first tape and the fourth portion of the second tape are spaced apart from each other when viewed in a first direction.

[0006] A secondary battery module according to one aspect of the present disclosure includes a plurality of the above-described secondary batteries stacked in a first direction.

[0007] According to various aspects of the present disclosure, a secondary battery and a secondary battery module with improved volumetric energy density are provided.

[0008] 1 is a schematic perspective view showing a secondary battery according to one embodiment. It is an exploded perspective view showing the internal configuration of the secondary battery shown in FIG. 1. It is a cross-sectional view of the secondary battery shown in FIG. 1 taken along line III-III. It is a see-through view of the secondary battery shown in FIG. 1 as viewed in a third direction. It is a cross-sectional view of the secondary battery shown in FIG. 1 taken along line V-V. It is a see-through view of the secondary battery shown in FIG. 1 as viewed in a second direction. It is a cross-sectional view of the electrode assembly shown in FIG. 2 taken along line VII-VII. It is a cross-sectional view of the electrode assembly shown in FIG. 2 taken along line VIII-VIII. It is a diagram showing (a) the arrangement of the first tape and the third tape, and (b) the positional relationship between the first tape and the third tape and the second tape. It is a diagram showing (a) the arrangement of the first tape and (b) the positional relationship between the first tape and the second tape in a different embodiment. It is a diagram showing (a) the arrangement of the first tape and (b) the positional relationship between the first tape and the second tape in a different embodiment. It is a diagram showing (a) the arrangement of the first tape and (b) the positional relationship between the first tape and the second tape in a different embodiment. 18A and 18B are diagrams showing different aspects of (a) the arrangement of the first tape and (b) the positional relationship between the first tape and the second tape; FIG. 18B are diagrams showing different aspects of (a) the arrangement of the first tape and (b) the positional relationship between the first tape and the second tape; FIG. 18C are diagrams showing different aspects of (a) the arrangement of the first tape and (b) the positional relationship between the first tape and the second tape; FIG. 18C are schematic perspective views showing a secondary battery module according to an embodiment; FIG. 18D are side views of the secondary battery module shown in FIG. 15; FIG. 18E are diagrams showing two secondary batteries included in the secondary battery module; FIG. 18F are diagrams showing the positional relationship between the exterior tapes of the secondary battery shown in FIG. 18; and FIG. 18G are diagrams showing different aspects of the secondary battery module according to an embodiment.

[0009] The technical solutions in the examples of the present application are described below in detail and clearly. Obviously, the described examples are only some examples of the present application, but not all examples. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs. The terms used in the specification of the present application are intended only to describe specific embodiments and are not intended to limit the present application.

[0010]

[0032] The following describes in detail the embodiments of the present application. However, the present application may be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that the present disclosure will be thorough and detailed and will convey the present disclosure to those skilled in the art.

[0011] Furthermore, the sizes or thicknesses of various components, layers may be exaggerated in the drawings for simplicity and clarity. Like numbers refer to like elements throughout the specification. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, when element A is referred to as "connecting" element B, element A may be directly connected to element B, or there may be an intervening element C, and elements A and B may be indirectly connected to each other.

[0012] Furthermore, the term "can" when used in describing embodiments of the present application can refer to one or more embodiments of the present application.

[0013] The terminology used herein is for the purpose of describing particular embodiments and is not intended to limit the present application. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. The terms "comprise," "have," and "include," as used herein, specify the presence of features, values, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, values, steps, operations, elements, components, and / or groups thereof.

[0014] Spatially related terms, such as "above," may be used herein for ease of description to describe the relationship of one element or feature to another element or feature as shown in the figures. Spatially related terms are intended to encompass different orientations of a device or devices in use or operation in addition to the orientation shown in the figures. For example, if a device in a figure were turned over, an element described as being "above" or "on" another element or feature would be oriented "below" or "below" the other element or feature. Thus, the term "above" can encompass an up-down orientation. Terms such as first, second, and third may be used herein to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer or section described below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0015] In this application, the design relationship between parameter values ​​is greater than, less than, or not equal to the reasonable error of the measuring device.

[0016] As shown in FIGS. 1 and 2 , a secondary battery 10 according to one embodiment includes an electrode assembly 20 enclosed in an exterior body 12 .

[0017] The electrode assembly 20 has a laminated structure stacked along a first direction D1. As shown in FIGS. 3 and 4 , the electrode assembly 20 includes a plurality of positive electrode layers 22, a plurality of negative electrode layers 24, and a plurality of separators 26. The positive electrode layers 22 and the negative electrode layers 24 are alternately stacked along the first direction D1, with a separator 26 interposed between each adjacent positive electrode layer 22 and negative electrode layer 24. In this embodiment, the electrode assembly 20 includes three positive electrode layers 22, four negative electrode layers 24, and six separators 26. The positive electrode layers 22, the negative electrode layers 24, and the separators 26 all have a rectangular shape with long and short sides of approximately the same dimensions when viewed in the first direction D1, and the electrode assembly 20 as a whole has an outer shape like a rectangular plate. In the following description, the direction along the long side of the electrode assembly 20 when viewed from the first direction D1 is referred to as the second direction D2, and the direction along the short side (a side shorter than the long side) of the electrode assembly 20 when viewed from the first direction D1 is referred to as the third direction D3. The second direction D2 and the third direction D3 are orthogonal to the first direction D1, and the second direction D2 and the third direction D3 are orthogonal to each other.

[0018] The positive electrode layer 22 is composed of a current collector and a positive electrode active material formed on both sides of the current collector. Examples of the positive electrode active material include, but are not limited to, lithium cobalt oxide, NCM (nickel cobalt manganate), NCA (nickel cobalt aluminum oxide), LMO (lithium manganate), and LFP (lithium iron phosphate). The negative electrode layer 24 is composed of a current collector and a negative electrode active material formed on both sides of the current collector. Examples of the negative electrode active material include, but are not limited to, carbon-based materials such as graphite, LTO (lithium titanate), silicon, and silicon oxide. The separator 26 is an insulating porous film. Examples of the separator 26 include, but are not limited to, a thin film made of an olefin polymer such as polypropylene, or a nonwoven fabric made of glass fiber or polyethylene.

[0019] 2 , the electrode assembly 20 has a first main surface 20a and a second main surface 20b extending in the second direction D2 and the third direction D3, and four side surfaces 20c, 20d, 20e, and 20f extending parallel to the first direction D1 and connecting the first main surface 20a and the second main surface 20b. Of the four side surfaces 20c, 20d, 20e, and 20f, the side surfaces 20c and 20d extend in the second direction D2, and the side surfaces 20e and 20f extend in the third direction D3. The side surface 20c is located on a first side 21c, which is a long side of the electrode assembly 20 when viewed in the first direction D1, and the side surface 20d is located on a second side 21d, which is a long side of the electrode assembly 20 when viewed in the first direction D1. The side surface 20e is located on a third side 21e, which is a short side of the electrode assembly 20 when viewed in the first direction D1, and the side surface 20f is located on a fourth side 21f, which is a short side of the electrode assembly 20 when viewed in the first direction D1. Because the electrode assembly 20 has a laminated structure, the side surfaces 20c, 20d, 20e, and 20f, which are formed by overlapping outer edges of each layer, are not, strictly speaking, continuous surfaces, but are formed by the positive electrode layer 22, the negative electrode layer 24, and the separator 26. However, in the present application, they are defined as such for the sake of convenience.

[0020] As shown in FIG. 3 , each of the positive electrode layers 22 has a positive electrode tab 23 extending outward from the side surface 20 e of the electrode assembly 20. The positive electrode tabs 23 extending from the positive electrode layers 22 are aggregated and fixed to one another so as to overlap one another. A rectangular plate-shaped first lead 30A extending along the second direction D2 is disposed at a position facing the side surface 20 e of the electrode assembly 20 in the second direction D2, and the positive electrode tabs 23 fixed to one another are connected to the first lead 30A. More specifically, the positive electrode tabs 23 fixed to one another are overlapped from below (i.e., from the second main surface 20 b side toward the first main surface 20 a side in the first direction D1) on a first end 31A of the first lead 30A facing the side surface 20 e of the electrode assembly 20 in the second direction D2 (i.e., the end portion closer to the side surface 20 e of the electrode assembly 20). Similarly, each of the multiple negative electrode layers 24 has a negative electrode tab 25 extending outward from the side surface 20f of the electrode assembly 20. The multiple negative electrode tabs 25 extending from the multiple negative electrode layers 24 are aggregated and fixed to one another so as to overlap one another. A rectangular plate-shaped second lead 30B extending along the second direction D2 is provided at a position facing the side surface 20f of the electrode assembly 20 in the second direction D2, and the multiple negative electrode tabs 25 fixed to one another are connected to the second lead 30B. More specifically, the multiple negative electrode tabs 25 fixed to one another are overlapped from below on a first end 31B of the second lead 30B facing the side surface 20f of the electrode assembly 20 in the second direction D2 (i.e., the end portion closer to the side surface 20f of the electrode assembly 20).

[0021] A first tape 40 is attached to the electrode assembly 20. The first tape 40 is, for example, a polymer tape. The polymer tape has a laminated structure of an adhesive surface and a non-adhesive surface. The adhesive surface contains at least one of a silicone polymer and an acrylic polymer, and may be composed of a single layer or multiple layers. The non-adhesive surface contains at least one of a polyester polymer, a polyamide polymer, a polyimide polymer, and a polyolefin polymer, and may be composed of a single layer or multiple layers. In this embodiment, the first tape 40 is composed of two loop-shaped tapes 40A arranged in the second direction D2. １ , 40A ２ Both tapes 40A １, 40A ２ Both tapes 40A have substantially the same shape and dimensions. １ , 40A ２ Each of the tapes 40A is wound around the electrode assembly 20 and attached so as to make approximately one full turn around an imaginary axis parallel to the second direction D2, and continuously covers a portion of the main surfaces 20a and 20b and a portion of the side surfaces 20c and 20d of the electrode assembly 20. As shown in FIG. １ , 40A ２ Each of the tapes 40A has a side surface covering portion 41 (first portion) that covers the side surfaces 20c and 20d of the electrode assembly 20, respectively, and a main surface covering portion 42 (second portion) that covers the main surfaces 20a and 20b, respectively. The side surface covering portion 41 extends along the first direction D1, and the main surface covering portion 42 extends along the third direction D3. １ , 40A ２ The tape 40A may be wound around two or more times, or may be separated from the tape 40A by less than one turn, or may be overlapped with the tape 40A by two or more turns. １ , 40A ２ The width in the second direction D2 is uniform around approximately one circumference. In the electrode assembly 20, the first tape 40 suppresses stacking misalignment of the positive electrode layer 22, the negative electrode layer 24, and the separator 26 in the stacked structure, and mainly suppresses stacking misalignment in the third direction D3.

[0022] An electrolyte solution is enclosed within the exterior body 12 together with the electrode assembly 20. The electrolyte solution fills the parts of the exterior body 12 where the electrode assembly 20 is not present. The electrolyte solution may contain air bubbles (voids).

[0023] In this embodiment, in addition to the first tape 40, a second tape 50 (third tape) is attached to the electrode assembly 20. The second tape 50 is, for example, a polymer tape. The polymer tape has a laminated structure including an adhesive surface and a non-adhesive surface. The adhesive surface contains at least one of a silicone-based polymer and an acrylic-based polymer and may be composed of a single layer or multiple layers. The non-adhesive surface contains at least one of a polyester-based polymer, a polyamide-based polymer, a polyimide-based polymer, and a polyolefin-based polymer and may be composed of a single layer or multiple layers. The second tape 50 is composed of a pair of tapes 50A and 50B attached to the side surface 20e of the electrode assembly 20 and a pair of tapes 50C and 50D attached to the side surface 20f. The tapes 50A and 50B are spaced apart from the positive electrode tab 23 extending from the side surface 20e and positioned to sandwich the positive electrode tab 23 in the third direction D3. The tapes 50A and 50B have substantially the same shape and dimensions. Both tapes 50A and 50B continuously cover portions of the principal surfaces 20a and 20b and portions of the side surface 20e of the electrode assembly 20 and terminate on the principal surfaces 20a and 20b. The tapes 50A and 50B may be attached so as to be bent in a U-shape. As shown in FIGS. 3 and 8 , both tapes 50A and 50B have a side surface covering portion 51 (fifth portion) covering the side surface 20e of the electrode assembly 20 and a main surface covering portion 52 (sixth portion) covering the principal surfaces 20a and 20b, respectively. The side surface covering portion 51 extends along the first direction D1, and the main surface covering portion 52 extends along the second direction D2. The tapes 50C and 50D are spaced apart from the negative electrode tab 25 extending from the side surface 20f and positioned to sandwich the negative electrode tab 25 in the third direction D3. The tapes 50C and 50D have substantially the same shape and dimensions. Both tapes 50C and 50D continuously cover parts of the principal surfaces 20a and 20b and parts of the side surfaces 20f of the electrode assembly 20 and terminate on the principal surfaces 20a and 20b. The tapes 50C and 50D may be attached so as to be bent in a U-shape. As shown in Figures 3 and 8, both tapes 50C and 50D have side surface covering portions 51 that cover the side surfaces 20f of the electrode assembly 20 and main surface covering portions 52 that cover the principal surfaces 20a and 20b, respectively.The side surface covering portion 51 extends in the first direction D1, and the main surface covering portion 52 extends in the second direction D2. In this embodiment, the tapes 50A to 50D all have a uniform width in the third direction D3 over their entire lengths, and have the same width as one another. In the electrode assembly 20, the second tape 50 suppresses stacking misalignment of the positive electrode layer 22, the negative electrode layer 24, and the separator 26 in the stacked structure, primarily suppressing stacking misalignment in the second direction D2.

[0024] The exterior body 12 is pouch-shaped and includes a pair of exterior sheets 12A and 12B, as shown in FIG. 2 . The pair of exterior sheets 12A and 12B sandwich the electrode assembly 20 in the first direction D1. The exterior sheet 12A covers the electrode assembly 20 from the first main surface 20a side, and the exterior sheet 12B covers the electrode assembly 20 from the second main surface 20b side. The exterior sheet 12A forms the main surface 12a of the exterior body 12 that faces the first main surface 20a of the electrode assembly 20 in the first direction D1, and the exterior sheet 12B forms the main surface 12b of the exterior body 12 that faces the second main surface 20b of the electrode assembly 20 in the first direction D1. Both of the pair of exterior sheets 12A and 12B have dimensions larger than the dimensions of the electrode assembly 20 when viewed in the first direction D1. As viewed in the first direction D1, a composite portion 15 in which the exterior sheets 12A and 12B overlap is formed around the electrode assembly 20. The first lead 30A extends outward from inside the exterior body 12 through the composite portion 15 of the pair of exterior sheets 12A and 12B, and its second end 32A is exposed from one end 12c of the exterior body 12 in the second direction D2. Similarly, the second lead 30B extends outward from the composite portion 15 of the pair of exterior sheets 12A and 12B, and its second end 32B is exposed from the other end 12d of the exterior body 12 in the second direction D2. Note that the first lead 30A and the second lead 30B may be exposed from the same end of the exterior body 12 in the second direction D2.

[0025] In this embodiment, the composite portion 15, in which the first side 21 c and the second side 21 d of the electrode assembly 20 face each other in the third direction D3 as viewed in the first direction D1, is folded back in the first direction D1 from the second main surface 20 b toward the first main surface 20 a to form the folded back portion 16. The folded back portion 16 extends along the second direction D2 over the entire length of the side surfaces 20 c, 20 d of the electrode assembly 20 in the second direction D2.

[0026] An exterior tape 60 (second tape) is attached to the exterior body 12. The exterior tape 60 is, for example, a polymer tape. The polymer tape has a laminated structure of an adhesive surface and a non-adhesive surface, and the adhesive surface contains at least one of a silicone polymer and an acrylic polymer, and may be composed of a single layer or multiple layers. The non-adhesive surface contains at least one of a polyester polymer, a polyamide polymer, a polyimide polymer, and a polyolefin polymer, and may be composed of a single layer or multiple layers. In this embodiment, the exterior tape 60 is made up of three pairs of tapes 60A. １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ Tape 60A １ , 60A ２ , 60A ３ are provided on the side surface 20d of the electrode assembly 20 and are aligned in the second direction D2. １ , 60B ２ , 60B ３ are provided on the side surface 20c of the electrode assembly 20 and are aligned in the second direction D2. １ and 60B １ , tape 60A ２ and 60B ２ , tape 60A ３ and 60B ３ are aligned to overlap when viewed in the third direction D3, forming a pair. １ and 60B １ The tape pair 63 is formed by the tape 60A, which overlaps when viewed in the third direction D3. ２ and 60B ２The tape pair 64 is formed by the tape 60A, which overlaps when viewed in the third direction D3. ３ and 60B ３ The tape pair 65 is formed by the tape 60A. １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ have substantially the same shape and dimensions. １ , 60A ２ , 60A ３ Each of the tapes 60A is attached so as to be bent in a U-shape, and continuously covers a part of the main surfaces 20a and 20b and a part of the side surface 20d of the electrode assembly 20 via the outer casing 12, and terminates on the main surfaces 12a and 12b of the outer casing 12. １ , 60A ２ , 60A ３ 5, each of the tape 60A and the tape 60B has a side covering portion 61 (third portion) that covers the side surface 20d of the electrode assembly 20 via the exterior body 12, and a main surface covering portion 62 (fourth portion) that covers the main surfaces 20a and 20b of the electrode assembly 20 via the exterior body 12. １ , 60A ２ , 60A ３ Each of the side covering portions 61 is attached to the exterior body 12 in an area covering the side surface 20d of the electrode assembly 20, and the tape 60A １ , 60A ２ , 60A ３ The main surface covering portions 62 of the tape 60B are attached to the exterior body 12 in areas that respectively cover the main surfaces 20a, 20b of the electrode assembly 20. The side surface covering portions 61 extend along the first direction D1, and the main surface covering portions 62 extend along the third direction D3. １ , 60B ２ , 60B ３ In both cases, tape 60A １ , 60A ２ , 60A ３Similarly to the tape 60B, the tape 60B is attached so as to be bent in a U-shape, and continuously covers a part of the main surfaces 20a and 20b and a part of the side surface 20c of the electrode assembly 20 via the outer casing 12, and terminates on the main surfaces 12a and 12b of the outer casing 12. １ , 60B ２ , 60B ３ As shown in FIG. 5 , each of the tapes 60B has a side covering portion 61 that covers the side surface 20c of the electrode assembly 20 via the exterior body 12, and a main surface covering portion 62 that covers the main surfaces 20a and 20b of the electrode assembly 20 via the exterior body 12. １ , 60B ２ , 60B ３ Each of the side covering portions 61 is attached to the exterior body 12 in an area covering the side surface 20c of the electrode assembly 20, and the tape 60B １ , 60B ２ , 60B ３ The main surface covering portions 62 of the tape 60A are attached to the exterior body 12 in areas that respectively cover the main surfaces 20a, 20b of the electrode assembly 20. The side surface covering portions 61 extend along the first direction D1, and the main surface covering portions 62 extend along the third direction D3. In this embodiment, the tape 60A １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ The tapes 60A of the exterior tape 60 all have a uniform width in the second direction D2 over the entire length and have the same width as each other. １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ Each of the side covering portions 61 covers the side surfaces 20c, 20d of the electrode assembly 20 via the folded portion 16 of the exterior body 12, thereby maintaining the shape of the folded portion 16 folded upward. By the exterior tape 60 maintaining the shape of the folded portion 16, it is possible to prevent the folded portion 16 from unfolding and increasing the external dimensions of the secondary battery 10.

[0027] Next, the overlapping of the first tape 40, the second tape 50, and the exterior tape 60 in the first direction D1 will be described with reference to FIG.

[0028] As shown in FIG. 9A, when viewed in the first direction D1, the tape 40A of the first tape 40 １ , 40A ２ The main surface covering portions 42 of the first tape 40 and the main surface covering portions 52 of the tapes 50A to 50D of the second tape 50 are located on the first main surface 20a of the electrode assembly 20. When viewed in the first direction D1, the tape 40A １ , 40A ２ Each of the main surface covering portions 42 of the tape 40A extends along the third direction D3 from a first side 21c, which is the long side corresponding to the side surface 20c of the electrode assembly 20, to a second side 21d, which is the long side corresponding to the side surface 20d. Reference symbol L1 indicates an imaginary reference line that passes through the center C of the electrode assembly 20 in the second direction D2 and the third direction D3 and is parallel to the third direction D3, and is equidistant from the third side 21e and the fourth side 21f of the electrode assembly 20. １ , 40A ２ The principal surface covering portions 42 of the tape 40A are disposed on either side of the virtual reference line L1. １ , 40A ２ The main surface covering portions 42 of the tape 40A may have a line-symmetric relationship with respect to the virtual reference line L1, and are spaced apart from the virtual reference line L1 by an equal distance. １ , 40A ２ The main surface covering portion 42 is located at a position that divides the first main surface 20a of the electrode assembly 20 into approximately three equal parts in the second direction D2.

[0029] When viewed in the first direction D1, tapes 50A and 50B of the second tape 50 extend from the third side 21e along the second direction D2 toward the virtual reference line L1, and tapes 50C and 50D of the second tape 50 extend from the fourth side 21f along the second direction D2 toward the virtual reference line L1. When viewed in the first direction D1, tapes 50A to 50D of the second tape 50 are all spaced apart from the virtual reference line L1. When viewed in the first direction D1, the main surface covering portion 52 of each of tapes 50A to 50D of the second tape 50 may be rectangular. Tapes 50A and 50B are disposed on either side of the virtual reference line L1, and tapes 50C and 50D are disposed on either side of the virtual reference line L1. The tapes 50A to 50D may be symmetrical with respect to the virtual reference line L1, with the respective main surface covering portions 52 of the tapes 50A and 50C being equidistant from the virtual reference line L1, and the respective main surface covering portions 52 of the tapes 50B and 50D being equidistant from the virtual reference line L1. Furthermore, the symbol L2 denotes a virtual reference line parallel to the second direction D2 that passes through the center C of the electrode assembly 20 in the second direction D2 and the third direction D3, and the virtual reference line L2 is equidistant from the first side 21c and the second side 21d of the electrode assembly 20. The tapes 50A and 50C are disposed on either side of the virtual reference line L2, and the tapes 50B and 50D are disposed on either side of the virtual reference line L2. The main surface covering portions 52 of the tapes 50A and 50B may have a line-symmetrical relationship with respect to the imaginary reference line L2, and are spaced an equal distance from the imaginary reference line L2, and the main surface covering portions 52 of the tapes 50C and 50D are spaced an equal distance from the imaginary reference line L2. Note that the second main surface 20b of the electrode assembly 20 also has a tape 40A of the first tape 40 having the same shape and position as that shown in FIG. １ , 40A ２ The main surface covering portions 42 of the first tape 50 and the main surface covering portions 52 of the tapes 50A to 50D of the second tape 50 are located on the tape holder 10.

[0030] As shown in FIG. 9B, when viewed in the first direction D1, the tape 60A of the exterior tape 60 １ , 60A ２ , 60A ３ , 60B１ , 60B ２ , 60B ３ Each of the main surface covering portions 62 is located on the main surface 12a of the exterior body 12. When viewed in the first direction D1, the tape 60A of the exterior tape 60 １ , 60A ２ , 60A ３ Each of the main surface covering portions 62 of the tape 60B of the exterior tape 60 overlaps with the side surface 20d of the electrode assembly 20 and extends from the side surface 20d toward the imaginary reference line L2. １ , 60B ２ , 60B ３ Each of the main surface covering portions 62 of the tape 60A overlaps the side surface 20c of the electrode assembly 20 and extends from the side surface 20c toward the imaginary reference line L2. １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ Each of the main surface covering portions 62 of the tape 60A may have a rectangular shape. １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ The main surface covering portion 62 of each of the first tape 40 and the tape 40A １ , 40A ２ The main surface covering portions 42 of the first tape 50 and the main surface covering portions 52 of the second tape 50 are located at positions different from and spaced apart from each other. １ , 60A ２ , 60A ３ The main surface covering portion 62 of the tape 60A may have a line-symmetric relationship with respect to the virtual reference line L1. １ The main surface covering portion 62 of the tape 40A in the second direction is １ and the tape 60A is located between the main surface covering portion 42 and the side surface 20e. ２ The main surface covering portion 62 of the tape 40A １ The main surface covering portion 42 and the tape 40A ２and the tape 60A. ３ The main surface covering portion 62 of the tape 40A in the second direction D2 is ２ The tape 60B is located between the main surface covering portion 42 and the side surface 20f. １ , 60B ２ , 60B ３ The main surface covering portion 62 of the tape 60B may have a line-symmetric relationship with respect to the virtual reference line L1. １ The main surface covering portion 62 of the tape 40A in the second direction is １ and the tape 60B is located between the main surface covering portion 42 and the side surface 20e. ２ The main surface covering portion 62 of the tape 40A １ The main surface covering portion 42 and the tape 40A ２ and the tape 60B. ３ The main surface covering portion 62 of the tape 40A in the second direction D2 is ２ The main surface covering portion 42 is located between the side surface 20f.

[0031] The tape 60A of the exterior tape 60 having the same shape and position as shown in FIG. 9(b) is also provided on the main surface 12b of the exterior body 12. １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ The respective main surface covering portions 62 are located.

[0032] When the first tape 40 and the exterior tape 60 overlap in the first direction D1, the first tape 40 is interposed between the exterior tape 60 and the electrode assembly 20 in the first direction D1, and because of the interposed first tape 40, the overall height of the secondary battery 10 (i.e., the length in the first direction D1) is the sum of the height of the electrode assembly 20, the height of the first tape 40, and the height of the exterior tape 60. In the secondary battery 10 described above, the first tape 40 and the exterior tape 60 are spaced apart in the first direction D1, and the first tape 40 is not interposed between the exterior tape 60 and the electrode assembly 20 in the first direction D1. This reduces the height dimension of the secondary battery 10, and thereby enables a high volumetric energy density to be achieved by reducing the external dimensions of the secondary battery 10.

[0033] Furthermore, the first tape 40 may suppress volume expansion associated with charge / discharge reactions of the electrode assembly 20. The exterior tape 60 may suppress volume expansion associated with charge / discharge reactions of the electrode assembly 20, particularly suppressing volume expansion in areas where the first tape 40 is not located. If the entire surface of the electrode assembly 20 is covered with the first tape, the external dimensions of the electrode assembly 20 are reduced, but stress associated with volume expansion acts on the electrode assembly 20 without being released. This makes it easier for stacking misalignment of the electrode assembly 20 and electrode breakage to occur.

[0034] The overlap between the first tape 40 and the exterior tape 60 is not limited to the configuration shown in FIG. 9, but may be any of the configurations shown in FIGS. 10 to 15, for example.

[0035] In the embodiment shown in FIG. 10, as shown in FIG. 10(a), when viewed in the first direction D1, the two loop-shaped tapes 40A of the first tape 40 are １ , 40A ２ Each of the main surface covering portions 42 of the tape 40A is located on the first main surface 20a of the electrode assembly 20. １ , 40A ２ have an asymmetric relationship with respect to the virtual reference line L1, and the tape 40A １ , 40A ２The distances from the virtual reference line L1 of the main surface covering portions 42 of the first tape 40 are different. １ , 40A ２ As shown in FIG. 10B, the tape 60A of the exterior tape 60 has the same shape and position as that shown in FIG. １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ Each of the main surface covering portions 62 is located on the main surface 12a of the exterior body 12. In the embodiment shown in FIG. １ and tape 60B １ The main surface covering portions 62 of the first tape 40 are aligned with the tape 40A of the first tape 40 in the first direction D1. １ The tape 60A of the exterior tape 60 is partially overlapped with the main surface covering portion 42 of the exterior tape 60. ２ , 60A ３ and tape 60B ２ , 60B ３ Each of the main surface covering portions 62 is spaced apart from any of the main surface covering portions 42 of the first tape 40 in the first direction D1.

[0036] In the embodiment shown in FIG. 10, the tape 40A of the first tape 40 in the first direction D1 ２ and the tape 60A of the exterior tape 60 ２ , 60A ３ , 60B ２ , 60B ３ 10 , the first tape 40 may be asymmetric with respect to the virtual reference line L1 when viewed in the first direction D1. Alternatively, the second tape 50 may not be provided.

[0037] In the embodiment shown in FIG. 11, as shown in FIG. 11(a), when viewed in the first direction D1, the two loop-shaped tapes 40A of the first tape 40 are １ , 40A２ Each of the main surface covering portions 42 of the tape 40A is located on the first main surface 20a of the electrode assembly 20. １ , 40A ２ have an asymmetric relationship with respect to the virtual reference line L1, and the tape 40A １ , 40A ２ The distances of the main surface covering portions 42 of the tape 40A from the virtual reference line L1 are different. １ Length (width) W1 and tape 40A ２ In this embodiment, the length W2 of the tape 40A is different from the length W1 of the tape 40A. １ The length W1 of the tape 40A ２ 11A. The length W2 of the first tape 40 is longer than the length W2 of the second tape 40A of the first tape 40 on the second main surface 20b of the electrode assembly 20. The shape and position of the first tape 40A are the same as those shown in FIG. １ , 40A ２ As shown in FIG. 11B, when viewed in the first direction D1, the three pairs of tapes 60A of the exterior tape 60 are positioned in the same direction. １ and 60B １ , 60A ２ and 60B ２ , 60A ３ and 60B ３ Each of the main surface covering portions 62 of the tape 60A is located on the main surface 12a of the exterior body 12. １ , 60A ２ , 60A ３ are provided on the side surface 20d of the electrode assembly 20 and are aligned in the second direction D2. １ , 60A ２ , 60A ３ The respective main surface covering portions 62 of the tape 60A have an asymmetric relationship with respect to the virtual reference line L1. １ The tape 40A in the second direction D2 of the main surface covering portion 62 １ The length W3 of the tape 60A ２ , tape 60A ３ The length W4 is longer than the length W4 common to the tape 60A. １ The main surface covering portion 62 of the tape 40A １ The tape 60A is located closer to the side surface 20e than the main surface covering portion 42.２ The main surface covering portion 62 of the tape 40A ２ The main surface covering portion 42 and the tape 40A ３ The tape 60A is located between the main surface covering portion 42 of the tape 60A. ３ The main surface covering portion 62 of the tape 40A ３ The tape 60B is located closer to the side surface 20f than the main surface covering portion 42. １ , 60B ２ , 60B ３ are provided on the side surface 20c of the electrode assembly 20 and are aligned in the second direction D2. １ , 60A ２ , 60A ３ and tape 60B １ , 60B ２ , 60B ３ are aligned to face each other in the third direction D3 to form a pair.

[0038] In the embodiment shown in FIG. 11, the tape 40A of the first tape 40 in the first direction D1 １ , 40A ２ and the tape 60A of the exterior tape 60 １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ 11 , the height of the secondary battery 10 is reduced, and the external dimensions of the secondary battery 10 are reduced. When there are multiple first tapes 40, as in the embodiment shown in FIG. 11 , the tape widths may be the same or different.

[0039] In the embodiment shown in FIG. 12, as shown in FIG. 12(a), when viewed in the first direction D1, the three loop-shaped tapes 40A of the first tape 40 are １ , 40A ２ , 40A ３ Each of the main surface covering portions 42 of the tape 40A is located on the first main surface 20a of the electrode assembly 20. １ , 40A ２ , 40A ３ The respective main surface covering portions 42 of the tape 40A have an asymmetric relationship with respect to the virtual reference line L1. １ , 40A ２The main surface covering portion 42 of each of the tapes 40A is biased toward the side surface 20e from the virtual reference line L1. ３ The main surface covering portion 42 of the first tape 40 is biased toward the side surface 20f from the virtual reference line L1. １ , 40A ２ , 40A ３ The respective main surface covering portions 42 are located.

[0040] As shown in FIG. 12B, when viewed in the first direction D1, the three pairs of tapes 60A of the exterior tape 60 １ , 60A ２ , 60A ３ , 60B １ , 60B ２ , 60B ３ Each of the main surface covering portions 62 of the tape 60A is located on the main surface 12a of the exterior body 12. １ , 60A ２ , 60A ３ are provided on the side surface 20d of the electrode assembly 20 and are aligned in the second direction D2. １ , 60A ２ , 60A ３ The respective main surface covering portions 62 of the tape 60A have an asymmetric relationship with respect to the virtual reference line L1. １ The main surface covering portion 62 of the tape 60A is biased toward the side surface 20e from the virtual reference line L1. ２ , 60A ３ The main surface covering portion 62 of each of the tapes 60A is biased toward the side surface 20f from the imaginary reference line L1. １ The main surface covering portion 62 of the tape 40A １ The tape 60A is located closer to the side surface 20e than the main surface covering portion 42. ２ The main surface covering portion 62 of the tape 40A ２ The main surface covering portion 42 and the tape 40A ３ The tape 60A is located between the main surface covering portion 42 of the tape 60A. ３ The main surface covering portion 62 of the tape 40A ３ The tape 60B is located closer to the side surface 20f than the main surface covering portion 42. １ , 60B２ , 60B ３ are provided on the side surface 20c of the electrode assembly 20 and are aligned in the second direction D2. １ , 60A ２ , 60A ３ and tape 60B １ , 60B ２ , 60B ３ are aligned to face each other in the third direction D3 to form a pair.

[0041] 12, the first tape 40 and the exterior tape 60 do not overlap in the first direction D1, which reduces the height of the secondary battery 10 and the external dimensions of the secondary battery 10. １ , 40A ２ , 40A ３ The number of tape pairs constituting the exterior tape 60 may be the same as or different from the number of tape pairs constituting the exterior tape 60 .

[0042] In the embodiment shown in FIG. 13, as shown in FIG. 13(a), the first tape 40 is a loop-shaped tape 40A. １ and a pair of U-shaped tapes 40B １ , 40C １ When viewed in the first direction D1, the tape 40A １ , 40B １ , 40C １ Each of the main surface covering portions 42 of the tape 40A is located on the first main surface 20a of the electrode assembly 20. １ The main surface covering portion 62 of the tape 40B is biased toward the side surface 20e from the virtual reference line L1. １ , 40C １ The main surface covering portions 42 of the electrodes 20 are biased toward the side surface 20f from the virtual reference line L1. １ , 40B １ , 40C １ 13( b), the main surface covering portions 62 of the exterior tape 60, which have the same shape and position as those shown in FIG. 9( b), are located on the main surface 12 a of the exterior body 12.

[0043] 13 , the first tape 40 and the exterior tape 60 do not overlap in the first direction D1, which reduces the height of the secondary battery 10 and the external dimensions of the secondary battery 10. As in the embodiment shown in FIG. 13 , the first tape 40 may include both a looped tape and a U-shaped tape, or the first tape 40 may be composed of only a looped tape, or the first tape 40 may be composed of only a U-shaped tape.

[0044] In the embodiment shown in FIG. 14, the first tape 40 is made up of five U-shaped tapes 40B １ , 40B ２ , 40B ３ , 40C １ , 40C ２ Tape 40B １ , 40B ２ , 40B ３ is attached to the side surface 20d of the electrode assembly 20, and the tape 40C １ , 40C ２ As shown in FIG. 14A, the tape 40B is attached to the side surface 20c of the electrode assembly 20 when viewed in the first direction D1. １ , 40B ２ , 40B ３ The main surface covering portions 42 of the tape 40C are aligned along the long side corresponding to the side surface 20d of the electrode assembly 20. １ , 40C ２ The main surface covering portions 42 of the tape 40B are aligned along the long side corresponding to the side surface 20c of the electrode assembly 20. １ , 40B ２ , 40B ３ , 40C １ , 40C ２ The respective main surface covering portions 42 of the tape 40B are asymmetric with respect to the imaginary reference line L1, and are also asymmetric with respect to the imaginary reference line L2. １ , 40C １ The main surface covering portion 42 of each of the tapes 40B is biased toward the side surface 20e from the virtual reference line L1. ２ , 40B ３ , 40C ２The main surface covering portion 42 of each of the first and second tapes 40B is biased toward the side surface 20f from the virtual reference line L1. １ , 40B ２ , 40B ３ , 40C １ , 40C ２ 14( b), the main surface covering portions 62 of the armor tape 60, which have the same shape and position as those shown in FIG. 9( b), are located on the main surface 12 a of the armor 12.

[0045] 14 , the first tape 40 and the exterior tape 60 do not overlap in the first direction D1, thereby reducing the height of the secondary battery 10 and the overall dimensions of the secondary battery 10. When the first tape 40 includes a U-shaped tape attached to the side surface 20 d of the electrode assembly 20 and a U-shaped tape attached to the side surface 20 c of the electrode assembly 20, as in the embodiment shown in FIG. 14 , the U-shaped tapes do not have to be aligned to face each other in the third direction D3. Furthermore, the number of U-shaped tapes attached to the side surface 20 d of the electrode assembly 20 included in the first tape 40 and the number of U-shaped tapes attached to the side surface 20 c of the electrode assembly 20 may be the same or different.

[0046] In the embodiment shown in FIG. 15, the first tape 40 is a loop-shaped tape 40A. １ As shown in FIG. 15(a), the tape 40A １ The main surface covering portion 42 of the tape 40A is located on the first main surface 20a of the electrode assembly 20. １ are in a line-symmetric relationship with respect to the virtual reference line L1, and the tape 40A １ The main surface covering portion 42 of the first tape 40 is located on the virtual reference line L1. The second main surface 20b of the electrode assembly 20 also has the same shape and position as the tape 40A of the first tape 40 shown in FIG. １ As shown in FIG. 15(b), the exterior tape 60 is made up of a pair of U-shaped tapes 60A. １ , 60B １ and a pair of U-shaped tapes 60A２ , 60B ２ and tape 60A. １ , 60A ２ is attached to the side surface 20d of the electrode assembly 20 via the outer casing 12, and the tape 60B １ , 60B ２ The tape 60A is attached to the side surface 20c of the electrode assembly 20 via the outer casing 12. When viewed from the first direction D1, the tape 60A １ , 60A ２ The main surface covering portions 62 of the tape 60B are aligned along the long side corresponding to the side surface 20d of the electrode assembly 20. １ , 60B ２ The main surface covering portions 62 of the tape 60A are aligned along the long side corresponding to the side surface 20c of the electrode assembly 20. １ , 60A ２ , 60B １ , 60B ２ The main surface covering portions 62 of the tape 60A are in a line-symmetric relationship with respect to the virtual reference line L1. １ , 60B １ The main surface covering portion 42 of each of the tapes 60A is biased toward the side surface 20e from the virtual reference line L1. ２ , 60B ２ Each of the main surface covering portions 42 is biased toward the side surface 20f from the imaginary reference line L1.

[0047] 15 , the first tape 40 and the exterior tape 60 do not overlap in the first direction D1, which reduces the height of the secondary battery 10 and the external dimensions of the secondary battery 10. As in the embodiment shown in FIG. 15 , the first tape 40 may be made up of a single tape, and may be made up of, for example, a single loop-shaped tape or a single U-shaped tape.

[0048] 16 and 17 show a secondary battery module 1 according to one embodiment. The secondary battery module 1 includes a plurality of the above-described secondary batteries 10. The plurality of secondary batteries 10 are stacked in the same orientation in the first direction D1. In the secondary battery module 1 according to this embodiment, each of the plurality of secondary batteries 10 includes the first tape 40, the second tape 50, and the exterior tape 60 arranged as shown in FIG. 9. As shown in FIG. 17, a buffer member 70 is interposed between two adjacent secondary batteries 10 in the first direction D1. The buffer member 70 is, for example, a pad made of a soft elastic material. The buffer member 70 can almost completely fill the space between two adjacent secondary batteries 10 in the first direction D1. The main surface 70a (third main surface) of the buffer member 70 is in direct contact with the main surface 12b of the exterior body 12 of each secondary battery 10, which faces the main surface 70a, and the main surface covering portion 62 of the exterior tape 60 attached to the exterior body 12. The main surface 70b (third main surface) of the cushioning member 70 is in direct contact with the main surface 12a of the exterior body 12 of the secondary battery 10, which faces the main surface 70b, and with the main surface covering portion 62 of the exterior tape 60 attached to the exterior body 12. Because the cushioning member 70 has high elasticity, the cushioning member 70 deforms when the secondary battery 10 expands, and can absorb the expansion of the secondary battery 10 to some extent. This can prevent the external dimensions of the secondary battery module 1 from increasing due to the expansion of the secondary battery 10.

[0049] Although not shown in the embodiment, the plurality of secondary batteries 10 may be stacked in an inverted orientation in the first direction D1.

[0050] Furthermore, as described above, since each of the multiple secondary batteries 10 included in the secondary battery module 1 is designed to have a low profile, the secondary battery module 1 in which multiple secondary batteries 10 are stacked is also designed to have a low profile, and the external dimensions of the secondary battery module 1 are reduced.

[0051] The multiple secondary batteries 10 included in the secondary battery module 1 may have the same configuration or different configurations. For example, two secondary batteries 10 adjacent to each other in the first direction D1 in the secondary battery module 1 may have exterior tapes 60 arranged in different positions, as shown in Figures 18 and 19. In the configuration shown in Figures 18 and 19, secondary batteries 10A and 10B are adjacent to each other in the first direction D1, and the main surface covering portion 62 of the exterior tape 60A of secondary battery 10A and the main surface covering portion 62 of the exterior tape 60B of secondary battery 10B are spaced apart from each other when viewed in the first direction D1. As viewed in the first direction D1, the exterior tapes 60A of the secondary batteries 10A and the exterior tapes 60B of the secondary batteries 10B are alternately arranged along the second direction D2, and the main surface covering portion 62 of the exterior tapes 60A of the secondary batteries 10A and the main surface covering portion 62 of the exterior tapes 60B of the secondary batteries 10B are aligned and paired so as to face each other in the third direction D3. In the configuration shown in Figures 18 and 19, the exterior tapes 60A, 60B of two secondary batteries 10A, 10B adjacent to each other in the first direction D1 are spaced apart from each other as viewed in the first direction D1, thereby suppressing the height dimension of the secondary battery module 1 and reducing the overall dimensions of the secondary battery module 1.

[0052] As shown in Fig. 20 , two secondary batteries 10 adjacent to each other in the first direction D1 of the secondary battery module 1 may have different arrangements of the exterior tapes 60. Between two secondary batteries 10 adjacent to each other in the first direction D1, the exterior tapes 60 may completely overlap as shown in Fig. 17 , or may partially overlap as shown in Fig. 20 . Also, as shown in Fig. 20 , two secondary batteries 10 adjacent to each other in the first direction D1 of the secondary battery module 1 may have different arrangements of the first tapes 40. Between two secondary batteries 10 adjacent to each other in the first direction D1, the first tapes 40 may partially overlap each other.

[0053] As can be understood from the above description, the present specification discloses the following: [Supplementary Note 1] An electrode assembly including a positive electrode layer, a negative electrode layer overlapping the positive electrode layer, and a separator interposed between the positive electrode layer and the negative electrode layer, the electrode assembly having a first main surface and a second main surface extending in a second direction perpendicular to a first direction in which the positive electrode layer and the negative electrode layer overlap, and a side surface extending in the first direction to connect the first main surface and the second main surface, a first tape having a first portion covering a part of the side surface of the electrode assembly and a second portion covering a part of the first main surface and a part of the second main surface, the first tape being integrally attached from the first main surface through the side surface to the second main surface, and a pouch-shaped exterior body enclosing the electrode assembly. a second tape attached to the exterior body and having a third portion covering a portion of the side surface of the electrode assembly via the exterior body and a fourth portion covering a portion of the first main surface and a portion of the second main surface of the electrode assembly via the exterior body, and integrally covering from the first main surface of the electrode assembly through the side surface to the second main surface via the exterior body, wherein the second portion of the first tape and the fourth portion of the second tape are spaced apart from each other when viewed in the first direction. [Supplementary Note 2] The secondary battery according to Supplementary Note 1, comprising a plurality of the first tapes, wherein the second portions of at least some of the plurality of first tapes are spaced apart from the fourth portion of the second tape when viewed in the first direction. [Supplementary Note 3] The secondary battery according to Supplementary Note 2, wherein, when viewed in the first direction, the electrode assembly has a rectangular shape having first and second sides along the second direction and third and fourth sides along a third direction perpendicular to the first and second directions, and the first tape covers at least one of a first side surface connected to the first side and a second side surface connected to the second side of the electrode assembly. [Supplementary Note 4] The secondary battery according to Supplementary Note 3, wherein, when viewed in the first direction, a fourth portion of the second tape is interposed between second portions of a pair of first tapes adjacent along at least one of the first side and the second side of the electrode assembly.[Supplementary Note 5] The secondary battery according to Supplementary Note 3 or 4, wherein the exterior body includes a pair of exterior sheets that respectively cover the first main surface and the second main surface of the electrode assembly and have composite portions that overlap around the electrode assembly when viewed in the first direction, the composite portions of the pair of exterior sheets have first folded-back portions that are folded back to face the first side surface in the third direction, and the second tape integrally covers from the first main surface to the second main surface, covering the first folded-back portions via the exterior body, passing through the first side surface and covering the second main surface. [Supplementary Note 6] The secondary battery according to any one of Supplements 3 to 5, wherein the first tape extends between the first side and the second side when viewed in the first direction and is wound around the electrode assembly, covering the first side surface and the second side surface, respectively. [Supplementary Note 7] The secondary battery according to any one of Supplements 3 to 5, wherein a first portion of the first tape covers the first side surface, and the second portion extends from the first side along the third direction and terminates on the first main surface and the second main surface. [Appendix 8] The secondary battery according to any one of Appendices 3 to 7, wherein, when viewed in the first direction, the plurality of first tapes are arranged symmetrically with respect to a reference line that passes through the center of the electrode assembly and is parallel to the third direction. [Appendix 9] The secondary battery according to any one of Appendices 3 to 8, wherein, when viewed in the first direction, the plurality of first tapes are provided at equal intervals along the first side or the second side of the electrode assembly. [Appendix 10] The secondary battery according to any one of Appendices 3 to 9, comprising: a first lead connected to the positive electrode layer and a second lead connected to the negative electrode layer, wherein the first lead and the second lead extend in the second direction when viewed in the first direction, extending from the inside to the outside of the exterior body. [Appendix 11] The secondary battery according to Appendices 10, wherein, when viewed in the first direction, the first lead protrudes from the third side of the electrode assembly, and the second lead protrudes from the fourth side of the electrode assembly.[Appendix 12] The secondary battery according to any one of Appendices 3 to 11, further comprising a third tape having a fifth portion covering a portion of at least one of a third side surface connected to the third edge and a fourth side surface connected to the fourth edge of the electrode assembly, and a sixth portion covering a portion of the first main surface and a portion of the second main surface, the third tape being integrally attached from the first main surface to the second main surface while passing through at least one of the third side surface and the fourth side surface of the electrode assembly. [Appendix 13] The secondary battery according to Appendices 12, wherein, when viewed in the first direction, the sixth portion of the third tape is spaced apart from the second portion of the first tape and the fourth portion of the second tape. [Appendix 14] The secondary battery according to any one of Appendices 1 to 13, further comprising a plurality of the second tapes, and wherein, when viewed in the first direction, the fourth portions of at least some of the plurality of second tapes are spaced apart from the second portion of the first tape. [Supplementary Note 15] The secondary battery according to Supplementary Note 14, wherein, when viewed in the first direction, the electrode assembly has a rectangular shape having first and second sides along the second direction and third and fourth sides along a third direction perpendicular to the first and second directions, and the second tape covers, via the exterior body, at least one of a first side surface connected to the first side and a second side surface connected to the second side of the electrode assembly. [Supplementary Note 16] The secondary battery according to Supplementary Note 15, wherein, when viewed in the first direction, a second portion of the first tape is interposed between fourth portions of a pair of second tapes adjacent along at least one of the first and second sides of the electrode assembly. [Supplementary Note 17] The secondary battery according to Supplementary Note 15 or 16, wherein the second tape extends between the first and second sides when viewed in the first direction and is wound around the electrode assembly via the exterior body, covering the first and second side surfaces of the electrode assembly via the exterior body, respectively. [Appendix 18] The secondary battery according to appendix 15 or 16, wherein the third portion of the second tape covers the first side surface, and the fourth portion extends from the first edge along the third direction and terminates on the first main surface and the second main surface.[Appendix 19] The secondary battery according to any one of Appendices 15 to 18, wherein, when viewed in the first direction, the plurality of second tapes are arranged symmetrically with respect to a reference line that passes through the center of the electrode assembly and is parallel to the third direction. [Appendix 20] The secondary battery according to Appendices 1, comprising a plurality of the first tapes and a plurality of the second tapes, wherein, when viewed in the first direction, second portions of at least some of the plurality of first tapes are separated from fourth portions of any of the plurality of second tapes. [Appendix 21] The secondary battery according to any one of Appendices 1 to 20, wherein the lengths of the first tapes and the second tapes in the second direction are different. [Appendix 22] A secondary battery module comprising a plurality of the secondary batteries according to any one of Appendices 1 to 21 stacked in the first direction. [Appendix 23] The secondary battery module according to Appendices 22, wherein, when viewed in the first direction, fourth portions of the second tapes of the secondary batteries adjacent in the first direction at least partially overlap each other. [Appendix 24] A secondary battery module as described in Appendix 22 or 23, comprising a cushioning member interposed between adjacent secondary batteries in the first direction. [Appendix 25] A secondary battery module as described in Appendix 24, wherein the cushioning member has a third main surface and a fourth main surface in the first direction, the third main surface of the cushioning member is in direct contact with the exterior body of the secondary battery and a fourth portion of the second tape that face the third main surface, and the fourth main surface of the cushioning member is in direct contact with the exterior body of the secondary battery and a fourth portion of the second tape that face the fourth main surface.

[0054] 1...secondary battery module, 10...secondary battery, 12...exterior body, 12A, 12B...exterior sheet, 20...electrode assembly, 22...positive electrode layer, 23...positive electrode tab, 24...negative electrode layer, 25...negative electrode tab, 26...separator, 40...first tape, 50...second tape, 60...exterior tape, 30A...first lead, 30B...second lead, D1...first direction, D2...second direction, D3...third direction.

Claims

1. An electrode assembly including a positive electrode layer, a negative electrode layer overlapping the positive electrode layer, and a separator interposed between the positive electrode layer and the negative electrode layer, the electrode assembly having a first main surface and a second main surface extending in a second direction perpendicular to a first direction in which the positive electrode layer and the negative electrode layer overlap, and a side surface extending in the first direction to connect the first main surface and the second main surface; a first tape having a first portion covering a portion of the side surface of the electrode assembly and a second portion covering a portion of the first main surface and a portion of the second main surface, the first tape being integrally attached from the first main surface through the side surface to the second main surface; and a pouch-shaped exterior body enclosing the electrode assembly. a second tape attached to the outer casing and having a third portion covering a portion of the side surface of the electrode assembly via the outer casing and a fourth portion covering a portion of the first main surface and a portion of the second main surface of the electrode assembly via the outer casing, and integrally covering from the first main surface of the electrode assembly through the side surface to the second main surface via the outer casing, wherein when viewed in the first direction, the second portion of the first tape and the fourth portion of the second tape are spaced apart from each other.

2. A secondary battery as described in claim 1, comprising a plurality of the first tapes, and wherein, when viewed in the first direction, the second portions of at least some of the plurality of first tapes are spaced apart from the fourth portion of the second tape.

3. A secondary battery as described in claim 2, wherein, when viewed in the first direction, the electrode assembly has a rectangular shape having a first side and a second side along the second direction and a third side and a fourth side along a third direction perpendicular to the first direction and the second direction, and the first tape covers at least one of a first side surface connected to the first side and a second side surface connected to the second side of the electrode assembly.

4. A secondary battery as described in claim 3, wherein, when viewed in the first direction, a fourth portion of the second tape is interposed between second portions of a pair of adjacent first tapes along at least one of the first side and the second side of the electrode assembly.

5. A secondary battery as described in claim 3, wherein the exterior body comprises a pair of exterior sheets respectively covering the first main surface and the second main surface of the electrode assembly and having a composite portion overlapping around the electrode assembly when viewed in the first direction, the composite portions of the pair of exterior sheets have a first fold-back portion that is folded back to face the first side surface in the third direction, and the second tape covers the first fold-back portion from the first main surface via the exterior body, passes through the first side surface and integrally covers up to the second main surface.

6. A secondary battery as described in claim 3, wherein the first tape extends between the first side and the second side when viewed in the first direction and is wound around the electrode assembly, covering each of the first side and the second side.

7. A secondary battery as described in claim 3, wherein a first portion of the first tape covers the first side surface, and the second portion extends from the first edge along the third direction and terminates on the first principal surface and the second principal surface.

8. The secondary battery according to claim 3, wherein, when viewed in the first direction, the plurality of first tapes are arranged symmetrically with respect to a reference line that passes through the center of the electrode assembly and is parallel to the third direction.

9. The secondary battery according to claim 4, wherein the plurality of first tapes are arranged at equal intervals along the first side or the second side of the electrode assembly when viewed in the first direction.

10. A secondary battery as described in claim 3, comprising a first lead connected to the positive electrode layer and a second lead connected to the negative electrode layer, the first lead and the second lead extending in the second direction when viewed in the first direction and extending from the inside to the outside of the exterior body.

11. The secondary battery according to claim 10, wherein, when viewed in the first direction, the first lead protrudes from the third side of the electrode assembly, and the second lead protrudes from the fourth side of the electrode assembly.

12. A secondary battery as described in claim 3, further comprising a third tape having a fifth portion covering a portion of at least one of a third side surface connected to the third edge and a fourth side surface connected to the fourth edge of the electrode assembly, and a sixth portion covering a portion of the first main surface and a portion of the second main surface, the third tape passing through at least one of the third side surface and the fourth side surface of the electrode assembly and integrally attached from the first main surface to the second main surface.

13. The secondary battery according to claim 12, wherein, when viewed in the first direction, a sixth portion of the third tape is spaced apart from a second portion of the first tape and a fourth portion of the second tape.

14. A secondary battery as described in claim 1, comprising a plurality of said second tapes, and wherein, when viewed in the first direction, the fourth portions of at least some of said plurality of second tapes are spaced apart from the second portion of said first tape.

15. A secondary battery as described in claim 14, wherein, when viewed in the first direction, the electrode assembly has a rectangular shape having a first side and a second side along the second direction and a third side and a fourth side along a third direction perpendicular to the first direction and the second direction, and the second tape covers at least one of a first side surface connected to the first side and a second side surface connected to the second side of the electrode assembly via the outer casing.

16. A secondary battery as described in claim 15, wherein, when viewed in the first direction, the second portion of the first tape is interposed between fourth portions of a pair of second tapes adjacent to each other along at least one of the first side and the second side of the electrode assembly.

17. A secondary battery as described in claim 15, wherein the second tape extends between the first edge and the second edge when viewed in the first direction and is wound around the electrode assembly via the outer casing, covering the first side and the second side of the electrode assembly respectively via the outer casing.

18. A secondary battery as described in claim 15, wherein a third portion of the second tape covers the first side surface, and the fourth portion extends from the first edge along the third direction and terminates on the first principal surface and the second principal surface.

19. The secondary battery according to claim 15, wherein, when viewed in the first direction, the plurality of second tapes are arranged symmetrically with respect to a reference line that passes through the center of the electrode assembly and is parallel to the third direction.

20. A secondary battery as described in claim 1, comprising a plurality of the first tapes and a plurality of the second tapes, and when viewed in the first direction, the second portions of at least some of the plurality of first tapes are separated from any of the fourth portions of the plurality of second tapes.

21. The secondary battery according to claim 1, wherein the length of the first tape and the length of the second tape in the second direction are different.

22. A secondary battery module comprising a plurality of the secondary batteries according to claim 1 stacked in the first direction.

23. The secondary battery module according to claim 22, wherein, when viewed in the first direction, the fourth portions of the second tapes of the secondary batteries adjacent to each other in the first direction at least partially overlap each other.

24. The secondary battery module according to claim 22, further comprising a buffer member interposed between the secondary batteries adjacent to each other in the first direction.

25. A secondary battery module as described in claim 24, wherein the cushioning member has a third main surface and a fourth main surface in the first direction, the third main surface of the cushioning member is in direct contact with the exterior body of the secondary battery and a fourth portion of the second tape that faces the third main surface, and the fourth main surface of the cushioning member is in direct contact with the exterior body of the secondary battery and a fourth portion of the second tape that faces the fourth main surface.

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