Battery modules and battery stacks

Abstract

To provide a battery module including a holding structure in which increase in size is suppressed, and a battery stack having the battery module.SOLUTION: A battery module includes: a rectangular battery cell 20 flat in a thickness direction TD; and a frame 30 for holding the battery cell. The frame includes: a plate-shaped body wall 31 that overlaps with the battery cell in a thickness direction; a pair of opposite walls 32, 33, 34, 35 provided at both ends of the body wall in a direction different from the thickness direction and extending in the thickness direction so as to be opposed to the battery cell; and biasing units 41, 42, 43 provided on an inner surface 30A of at least one of the pair of opposite walls and extending toward the battery cell to bias the battery cell. A target wall to be a target on which the biasing unit is provided of the pair of opposite walls includes recessed portions 32A, 33A, 33B, 34A that are recessed so as to be locally separated from the battery cell at a portion where the biasing unit is provided.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The disclosure herein relates to a battery module. [Background technology]

[0002] Patent Document 1 describes a battery stack comprising multiple battery cells and a resin frame. A resin frame is disposed between adjacent battery cells. The resin frame comprises a main body and side walls provided at both longitudinal ends of the main body and extending beyond the side edges of the main body. One of the side walls is provided with a lip portion facing the other side wall. The lip portion urges the battery cells toward the other side of the side wall. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-93331 Summary of the Invention [Problem to be solved by the invention]

[0004] The sidewalls extend in one direction along the longitudinal edge of the battery cell. The sidewalls with lip portions extend in one direction along the longitudinal edge of the battery cell, at a distance from the battery cell in the longitudinal direction by the amount of the lip. The size of the resin frame increases by the amount of the lip portion.

[0005] An object of the present disclosure is to provide a battery module and a battery stack that are provided with a holding structure that suppresses an increase in size. [Means for solving the problem]

[0006] A battery module according to one aspect of the present disclosure includes: A rectangular battery cell (20) that is flat in the thickness direction (TD), a frame (30) for holding the battery cells; The frame is a plate-shaped main body wall (31) that overlaps the battery cell in the thickness direction; a pair of opposing walls (32, 33, 34, 35) provided at both ends of the main body wall in a direction different from the thickness direction and extending in the thickness direction so as to face the battery cells; a biasing portion (41, 42, 43) provided on an inner surface (30A) of at least one of the pair of opposing walls, extending toward the battery cell and biasing the battery cell; Of the pair of opposing walls, the target wall on which the biasing portion is provided has a recessed portion (32A, 33A, 33B, 34A) that is locally recessed so as to move away from the battery cell at the location where the biasing portion is provided. 、 The stiffness of the recess is higher than the stiffness of the extensions (33C, 32B, 34B) continuing from the recess in the target wall.

[0007] The area where the biasing portion is provided is locally recessed so as to move away from the battery cell, which prevents the frame from increasing in size, making it possible to provide a battery module with a frame that prevents an increase in size.

[0008] A battery stack according to one aspect of the present disclosure includes: a plurality of battery modules (10) stacked in the thickness direction (TD), each of which has a rectangular battery cell (20) that is flat in the thickness direction (TD) and a frame (30) that holds the battery cells; a bus bar (80) electrically connected to the plurality of battery cells; busbar holding walls (91, 92) that hold the busbars; The frame is a plate-shaped main body wall (31) that overlaps the battery cell in the thickness direction; a pair of opposing walls (32, 33, 34, 35) provided at both ends of the main body wall in a direction different from the thickness direction and extending in the thickness direction so as to face the battery cells; a biasing portion (41, 42, 43) provided on an inner surface (30A) of at least one of the pair of opposing walls, extending toward the battery cell and biasing the battery cell; Of the pair of opposing walls, the target wall on which the biasing portion is provided has a recessed portion (32A, 33A, 33B, 34A) that is locally recessed so as to move away from the battery cell at the location where the biasing portion is provided. 、 The stiffness of the recess is higher than the stiffness of the extensions (33C, 32B, 34B) continuing from the recess in the target wall.

[0009] The area where the biasing portion is provided is locally recessed so as to move away from the battery cell, which prevents the frame from increasing in size, making it possible to provide a battery stack with a frame that prevents an increase in size.

[0010] The reference numbers in parentheses above merely indicate the corresponding relationship with the configurations described in the embodiments below, and do not in any way limit the technical scope. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a plan view of the battery stack of the first embodiment. [Figure 2] FIG. 2 is a plan view of the battery stack of FIG. 1 with the bus bar case removed. [Figure 3] FIG. 2 is a cross-sectional view of the battery stack of the first embodiment. [Figure 4] FIG. 1 is a perspective view of a battery module according to a first embodiment. [Figure 5] FIG. 2 is a cross-sectional view of the battery module of the first embodiment. [Figure 6] FIG. 10 is an enlarged schematic view of a biasing portion. [Figure 7] FIG. 7 is a cross-sectional view of the battery module taken along line VII-VII shown in FIG. [Figure 8] FIG. 10 is a perspective view of a battery module according to a second embodiment. [Figure 9] FIG. 4 is a cross-sectional view of a battery module according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a battery module according to a third embodiment. [Figure 11] FIG. 10 is a cross-sectional view of a battery module according to a third embodiment. [Figure 12]FIG. 10 is a cross-sectional view of a battery module according to a fourth embodiment. [Figure 13] FIG. 10 is a cross-sectional view of a battery module according to a fifth embodiment. [Figure 14] FIG. 10 is a cross-sectional view of a battery module according to a sixth embodiment. [Figure 15] FIG. 13 is a cross-sectional view of a battery module according to a seventh embodiment. [Figure 16] 3A and 3B are schematic diagrams illustrating an example of an embodiment of a recessed portion. [Figure 17] 3A and 3B are schematic diagrams illustrating an example of an embodiment of a recessed portion. [Figure 18] 3A and 3B are schematic diagrams illustrating an example of an embodiment of a recessed portion. [Figure 19] 3A and 3B are schematic diagrams illustrating an example of an embodiment of a recessed portion. [Figure 20] 3A and 3B are schematic diagrams illustrating an example of an embodiment of a recessed portion. [Figure 21] 10A and 10B are schematic diagrams illustrating an example of an embodiment of a biasing portion. [Figure 22] 10A and 10B are schematic diagrams illustrating an example of an embodiment of a biasing portion. [Figure 23] 10A and 10B are schematic diagrams illustrating an example of an embodiment of a biasing portion. [Figure 24] 10A and 10B are schematic diagrams illustrating an example of an embodiment of a biasing portion. [Figure 25] 10A and 10B are schematic diagrams illustrating an example of an embodiment of a biasing portion. [Figure 26] 10A and 10B are schematic diagrams illustrating an example of an embodiment of a biasing portion. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicated explanations may be omitted. In each embodiment, when only a part of the configuration is described, the other previously described embodiments may be applied to the other parts of the configuration.

[0013] In addition to combinations of parts that are specifically expressly possible in each embodiment, it is also possible to partially combine embodiments, embodiments and variants, and variants even if not explicitly stated, as long as there are no problems with the combination.

[0014] (First embodiment) A battery module 10 and a battery stack 100 having a plurality of battery modules 10 will be described with reference to Figs. 1 to 3. Various components of the battery stack 100 are schematically shown in Figs. 4 to 7. Various components of the battery module 10 are schematically shown in Figs. 4 to 7. The battery stack 100 of the embodiment is applied to an electric vehicle such as an electric vehicle or a plug-in hybrid vehicle. Note that, hereinafter, the electric vehicle may be simply referred to as a vehicle.

[0015] Hereinafter, the width direction of the battery cell 20 may be referred to as the width direction WD. The height direction of the battery cell 20 may be referred to as the height direction HD. The thickness direction of the battery cell 20 may be referred to as the thickness direction TD. The width direction WD, the height direction HD, and the thickness direction TD are perpendicular to one another. In the drawings, the width direction WD may be simply referred to as "WD." The height direction HD may be simply referred to as "HD." The thickness direction TD may be simply referred to as "TD."

[0016] The drawings will now be described. FIG. 1 is a plan view of a battery stack 100 according to a first embodiment. FIG. 2 is a plan view of the battery stack 100 of FIG. 1 from which a bus bar case 90 has been removed. Note that the dashed dotted lines shown in FIG. 1 are shown in the same positions in FIG. 2. FIG. 3 is a cross-sectional view of the battery stack 100 according to the first embodiment. FIG. 4 is a perspective view of a battery module 10 according to the first embodiment. FIG. 5 is a cross-sectional view of the battery module 10 according to the first embodiment. FIG. 6 is a schematic enlarged view of a biasing portion 40. FIG. 7 is a cross-sectional view of the battery module 10 taken along line VII-VII shown in FIG. 5.

[0017] <Car battery> FIG. 1 shows a battery stack 100. A plurality of battery stacks 100 are mounted on a vehicle. The plurality of battery stacks 100 are connected in series or in parallel by a wire harness or the like. This constitutes an on-board power supply. The on-board power supply serves to supply power to the electrical loads of the vehicle. Note that the on-board power supply may be constituted by a single battery stack 100.

[0018] The battery stack 100 and the vehicle's smoke exhaust hose 110 are arranged side by side. The smoke exhaust hose 110 extends to the outside of the vehicle. Gas generated from the multiple battery cells 20 flows into this smoke exhaust hose 110. The gas is then discharged to the outside from the smoke exhaust hose 110. The on-board power supply can be located in any suitable location, such as the space under the front seats, the space under the rear seats, or the space between the rear seats and the trunk.

[0019] The battery stack 100 has a plurality of battery modules 10, a busbar module 60, and a battery case 70. The battery module 10 has battery cells 20 and a resin frame 30. The battery cells 20 are held by the resin frame 30. The resin frame 30 is formed using an electrically insulating material such as resin. The resin frame 30 has a frame structure capable of holding the battery cells 20. Details of the resin frame 30 will be explained later. The battery stack 100 is formed by stacking a plurality of battery cells 20. The plurality of battery cells 20 are housed in the battery case 70 in a stacked state in the thickness direction TD.

[0020] The battery case 70 has a case bottom wall 71 and case side walls 72. The case bottom wall 71 and case side walls 72 are integrally connected. The case bottom wall 71 and case side walls 72 are each formed of an electrically insulating resin material. The case bottom wall 71 has a thin, flat shape with a thickness in the height direction HD. The case bottom wall 71 has an inner bottom surface 71A spaced apart in the height direction HD and an outer bottom surface behind it. The case side walls 72 rise from the inner bottom surface 71A in the height direction HD. The case side walls 72 extend along the edge of the inner bottom surface 71A and form an annular shape in the circumferential direction around the height direction HD. The case bottom wall 71 and case side walls 72 form the storage space of the battery case 70.

[0021] A plurality of battery modules 10 are housed in the storage space of a battery case 70. The battery case 70 has a box shape with an opening in the height direction HD. The plurality of battery modules 10 are housed in the battery case 70 so that the electrode surfaces 20A of each battery cell 20 face the opening side. The battery cells 20 are stacked in the thickness direction TD so that their main surfaces 20C overlap each other. The battery cells 20 have positive and negative terminals 24 and 25 that protrude in the height direction HD at both ends in the width direction WD. The battery cells 20 are stacked in the width direction WD so that the positive and negative terminals 24 and 25 are alternately arranged.

[0022] Furthermore, a busbar module 60 is arranged to cover the electrode surfaces 20A of the multiple battery cells 20. The busbar module 60 has multiple busbars 80 that electrically connect the positive electrode terminals 24 and the negative electrode terminals 25, and a busbar case 90 that holds the multiple busbars 80. The busbars 80 are plate materials made of a metal with good conductivity, such as copper. The busbars 80 electrically connect the positive electrode terminals 24 and negative electrode terminals 25 of adjacent battery cells 20 in the thickness direction TD. This electrically connects the multiple battery cells 20 in series.

[0023] The bus bar case 90 is formed using an electrically insulating material such as resin. The bus bar case 90 is attached to, for example, the battery case 70 so as to cover the electrode surfaces 20A of the multiple battery cells 20. The bus bar case 90 is provided from one end of the battery case 70 to the other end in the thickness direction TD so as to hold the multiple bus bars 80. The bus bar case 90 has through holes 94 for passing the electrode terminals 24, 25 in the height direction HD. Note that the positive electrode terminal 24 and the negative electrode terminal 25 may be collectively referred to as the electrode terminals 24, 25. The electrode terminals 24, 25 pass through the through holes 94. The bus bars 80 are electrically and mechanically connected to the electrode terminals 24, 25 that pass through the through holes 94.

[0024] <Battery cell> Each of the plurality of battery cells 20 is a secondary battery. Examples of secondary batteries that can be used for the battery cells 20 include lithium ion secondary batteries, nickel-metal hydride secondary batteries, and organic radical batteries. These secondary batteries generate electromotive force through chemical reactions.

[0025] The battery cell 20 includes a power generating element and a metal case that houses the power generating element. The battery cell 20 has a rectangular shape that is flat in the thickness direction TD. The metal case has an electrode surface 20A and a bottom surface 20B that are aligned in the height direction HD, two main surfaces 20C that are aligned in the thickness direction TD, and two side surfaces 20D that are aligned in the width direction WD. The electrode surface 20A is sometimes referred to as the top surface. Of the six surfaces of the metal case, the two main surfaces 20C have larger areas than the other four surfaces.

[0026] Since the metal case is possessed by the battery cell 20, it can also be said that the battery cell 20 has these six surfaces. That is, the battery cell 20 has an electrode surface 20A and a bottom surface 20B aligned in the height direction HD, two main surfaces 20C aligned in the thickness direction TD, and two side surfaces 20D aligned in the width direction WD. A positive electrode terminal 24 and a negative electrode terminal 25 are formed on the electrode surface 20A. The positive electrode terminal 24 and the negative electrode terminal 25 are aligned and spaced apart in the width direction WD. The positive electrode terminal 24 is located on one of the two side surfaces 20D. The negative electrode terminal 25 is located on the other of the two side surfaces 20D.

[0027] <Resin frame> As described above, a plurality of battery cells 20 are housed in the battery case 70 in a stacked state in the thickness direction TD. Resin frames 30 are arranged between the stacked battery cells 20. In the battery stack 100, the battery cells 20 and the resin frames 30 are arranged alternately. The resin frames 30 are formed, for example, from an electrically insulating resin material, and are arranged between adjacent battery cells 20 as insulating members.

[0028] The resin frame 30 includes a main body wall 31, a top wall 33 and a bottom wall 35 spaced apart in the height direction HD, and a left side wall 32 and a right side wall 34 spaced apart in the width direction WD. The top wall 33 is provided at the top end of the main body wall 31 in the height direction HD. The bottom wall 35 is provided at the bottom end of the main body wall 31 in the height direction HD. The left side wall 32 is provided at the left end of the main body wall 31 in the width direction WD. The right side wall 34 is provided at the right end of the main body wall 31 in the width direction WD.

[0029] As described above, the battery cells 20 are held by the resin frame 30. The top wall 33 and bottom wall 35 each face the battery cells 20 in the height direction HD. The left side wall 32 and right side wall 34 each face the battery cells 20 in the width direction WD. For this reason, the top wall 33 and bottom wall 35 may be collectively referred to as the first facing wall. The left side wall 32 and right side wall 34 may be collectively referred to as the second facing wall. In other words, the resin frame 30 has a main body wall 31, a first facing wall, and a second facing wall.

[0030] Conversely, the first opposing wall has a top wall 33 and a bottom wall 35. The second opposing wall has a left side wall 32 and a right side wall 34. The top wall 33 may be referred to as the first side wall for convenience. The bottom wall 35 may be referred to as the second side wall for convenience. The right side wall 34 may be referred to as the third side wall for convenience. The left side wall 32 may be referred to as the fourth side wall for convenience. The resin frame 30 may be referred to as having a main body wall 31, a first side wall, a second side wall, a third side wall, and a fourth side wall.

[0031] The main body wall 31 has a rectangular plate shape. The main body wall 31 faces the main surface 20C of the battery cell 20 in the thickness direction TD. The main surface 20C of the battery cell 20 is the surface of the flat battery cell 20 with the largest area. The main body wall 31 is arranged so as to be sandwiched between adjacent battery cells 20 in the thickness direction TD.

[0032] The side walls 32, 34 are located outside the side surface 20D of the battery cell 20. The left side wall 32 and the right side wall 34 may be collectively referred to as the side walls 32, 34. The side walls 32, 34 extend from the edges of the main body wall 31 to both sides in the thickness direction TD. The side walls 32, 34 face the side surface 20D in the width direction WD. In other words, the side walls 32, 34 are provided so as to protrude from both ends of the main body wall 31 in the width direction WD to both sides in the thickness direction TD. The resin frame 30 has an I-shaped cross section when viewed from the height direction HD. The side walls 32, 34 restrict displacement of the battery cell 20 in the width direction WD.

[0033] The top wall 33 is located higher than the electrode surfaces 20A of the battery cells 20. The top wall 33 extends in the width direction WD to connect the left side wall 32 and the right side wall 34. The top wall 33 also extends from the edges of the body wall 31 in the width direction WD to both sides in the thickness direction TD, and faces part of the electrode surfaces 20A of the battery cells 20. In other words, the top wall 33 is provided so as to protrude from the ends of the body wall 31 in the width direction WD to both sides in the thickness direction TD. The top wall 33 faces each electrode surface 20A of an adjacent battery cell 20. The top wall 33 restricts upward displacement of the battery cells 20.

[0034] The bottom wall 35 is located lower than the lower surfaces 20B of the battery cells 20. The bottom wall 35 extends from the edges of the main body wall 31 on both sides in the thickness direction TD and faces part of the lower surfaces 20B. In other words, the bottom wall 35 is provided so as to protrude on both sides in the thickness direction TD from the lower end of the main body wall 31. The bottom wall 35 faces each lower surface 20B of an adjacent battery cell 20. The bottom wall 35 restricts downward displacement of the battery cells 20.

[0035] In this way, the resin frame 30 houses adjacent battery cells 20, surrounding the electrode surfaces 20A, side surfaces 20D, and bottom surfaces 20B. The battery cells 20 are held by the resin frame 30. The battery cells 20 are held in the resin frame 30 to form a battery module 10. The resin frame 30 prevents the battery cells 20 from shifting in position in the width direction WD and height direction HD. The resin frame 30 also supports the stacked battery cells 20 in the thickness direction TD.

[0036] <Energy applying part> In addition to the components described above, the resin frame 30 also includes a biasing portion 40. The biasing portion 40 includes a first biasing portion 41, a second biasing portion 42, and a third biasing portion 43. The first biasing portion 41 and the second biasing portion 42 are provided on the inner surface 30A of the top wall 33. The first biasing portion 41 and the second biasing portion 42 are provided on the inner surface 30A of the top wall 33, spaced apart in the width direction WD. The first biasing portion 41 and the second biasing portion 42 are arranged symmetrically about the center of the battery cell 20 in the width direction WD. The third biasing portion 43 is provided on the inner surface 30A of the right side wall 34. Other embodiments regarding the arrangement of the biasing portion 40 will be described later. The top wall 33 and the right side wall 34 are sometimes referred to as target walls, as they are the walls on which the biasing portion 40 is to be provided. The first urging portion 41 and the second urging portion 42 are sometimes referred to as first target urging portions because they are provided on the top wall 33, which is one of the target walls. The third urging portion 43 is sometimes referred to as second target urging portion because it is provided on the right side wall 34, which is another of the target walls.

[0037] <First biasing portion and second biasing portion> The first urging portion 41 and the second urging portion 42 extend in the height direction HD toward the bottom wall 35 so as to move away from the inner surface 30A of the top wall 33. In other words, the first urging portion 41 and the second urging portion 42 extend in the height direction HD toward the electrode surface 20A so as to move away from the inner surface 30A of the top wall 33. The first urging portion 41 and the second urging portion 42 extend so as to move away from each other in the width direction WD as they move away from the inner surface 30A of the top wall 33. The first urging portion 41 and the second urging portion 42 are substantially trapezoidal when viewed from the direction of the arrow shown in FIG. 6 . Note that the shapes of the first urging portion 41 and the second urging portion 42 are not limited to this. Note that other embodiments regarding the shapes of the first urging portion 41 and the second urging portion 42 will be described later.

[0038] The tip end of the first urging portion 41 and the tip end of the second urging portion 42 are in contact with the electrode surface 20A. The first urging portion 41 and the second urging portion 42 urge the battery cell 20 toward the bottom wall 35. As a result, the lower surface 20B of the battery cell 20 is pressed against the inner surface 30A of the bottom wall 35. The lower surface 20B abuts against the inner surface 30A of the bottom wall 35, defining the position of the battery cell 20 in the height direction HD, and therefore the inner surface 30A of the bottom wall 35 is sometimes referred to as a reference surface with respect to the height direction HD.

[0039] The top wall 33 described above is a portion that connects the left side wall 32 and the right side wall 34 that are spaced apart in the width direction WD. As the top wall 33 extends from the left side wall 32 toward the right side wall 34, the portions of the top wall 33 where the first urging portion 41 and the second urging portion 42 are formed are locally offset in the height direction HD so as to move away from the bottom wall 35. In other words, as the top wall 33 extends from the left side wall 32 toward the right side wall 34, the portions of the top wall 33 where the first urging portion 41 and the second urging portion 42 are formed are locally recessed in the height direction HD so as to move away from the bottom wall 35.

[0040] For this reason, the base of the first urging portion 41 and the base of the second urging portion 42 are each surrounded by a part of the top wall 33. The locally recessed portion in the top wall 33 where the first urging portion 41 is formed may be referred to as a first recessed portion 33A. The locally recessed portion in the top wall 33 where the second urging portion 42 is formed may be referred to as a second recessed portion 33B. The portion of the top wall 33 that continues to the first recessed portion 33A and / or the second recessed portion 33B may be referred to as a top wall extension portion 33C.

[0041] The top wall 33 has a first recessed portion 33A, a second recessed portion 33B, and a top wall extension 33C. One end of the first recessed portion 33A is connected to the left side wall 32 by the top wall extension 33C. The other end of the first recessed portion 33A is connected to one end of the second recessed portion 33B by the top wall extension 33C. The other end of the second recessed portion 33B is connected to the right side wall 34 by the top wall extension 33C. In this embodiment, the first recessed portion 33A and the second recessed portion 33B have the same shape, as an example. However, the shapes of the first recessed portion 33A and the second recessed portion 33B are not limited to being the same shape.

[0042] Furthermore, because first recessed portion 33A is bent so as to surround the base of first biasing portion 41, the section modulus of first recessed portion 33A is higher than the section modulus of top wall extension portion 33C. The rigidity of first recessed portion 33A is higher than the rigidity of top wall extension portion 33C. First recessed portion 33A is less likely to deform in the height direction HD than top wall extension portion 33C.

[0043] Similarly, because second recessed portion 33B is bent so as to surround the base portion of second biasing portion 42, the section modulus of second recessed portion 33B is higher than the section modulus of top wall extension portion 33C. The rigidity of second recessed portion 33B is higher than the rigidity of top wall extension portion 33C. Second recessed portion 33B is less likely to deform in the height direction HD than top wall extension portion 33C.

[0044] <Third biasing section> The third urging portion 43 extends in the width direction WD toward the left side wall 32 so as to move away from the inner surface 30A of the right side wall 34. In other words, the third urging portion 43 extends in the width direction WD toward the side surface 20D so as to move away from the inner surface 30A of the right side wall 34. The third urging portion 43 extends so as to move closer to the electrode surface 20A as it moves away from the inner surface 30A of the right side wall 34 in the width direction WD. Although not shown, the third urging portion 43 also has a generally trapezoidal shape similar to the first urging portion 41 and the second urging portion 42. Note that the shape of the third urging portion 43 is not limited to this. Other embodiments regarding the shape of the third urging portion 43 will be described later.

[0045] The tip of the third biasing portion 43 is in contact with the side surface 20D of the battery cell 20. The third biasing portion 43 biases the battery cell 20 toward the left side wall 32. The side surface 20D is pressed against the inner surface 30A of the left side wall 32. The side surface 20D is in contact with the inner surface 30A of the left side wall 32. Because the position of the battery cell 20 in the width direction WD is determined by the side surface 20D abutting against the inner surface 30A of the left side wall 32, the inner surface 30A of the left side wall 32 is sometimes referred to as a reference surface with respect to the width direction WD.

[0046] <Ceiling wall and top surface> A positive electrode terminal 24 and a negative electrode terminal 25 are provided on the electrode surface 20A of the battery cell 20, protruding from the electrode surface 20A in the height direction HD. The positive electrode terminal 24 and the negative electrode terminal 25 are provided on the electrode surface 20A near one of the two main surfaces 20C. A portion of the top wall 33 on one of the two main surfaces 20C is cut out to avoid the positive electrode terminal 24 and the negative electrode terminal 25. The positive electrode terminal 24 and the negative electrode terminal 25 are provided in a cutout 36 cut out of the top wall 33. A first recess 33A and a second recess 33B are provided in a portion of the top wall 33 on the other main surface 20C side that is aligned with the cutout 36.

[0047] The positive electrode terminal 24 and the negative electrode terminal 25 are exposed from the notch 36 in the top wall 33. The positive electrode terminal 24 and the negative electrode terminal 25 are equidistant from the electrode surface 20A. As described above, the first recessed portion 33A and the second recessed portion 33B have the same shape. The first recessed portion 33A and the second recessed portion 33B are equidistant from the top wall extension 33C. The protruding tip ends of the positive electrode terminal 24 and the negative electrode terminal 25 are located farther from the electrode surface 20A than the protruding tip ends of the first recessed portion 33A and the second recessed portion 33B.

[0048] The first recessed portion 33A and the second recessed portion 33B are located between the positive electrode terminal 24 and the negative electrode terminal 25 in the width direction WD. When the first recessed portion 33A and the second recessed portion 33B are located near the outer ends of the electrode terminals 24 and 25 in the width direction WD, curved portions are formed at the ends because the metal case is generally manufactured by drawing. If the first recessed portion 33A and / or the second recessed portion 33B are located at the curved portions, it becomes difficult for the first biasing portion 41 and / or the second biasing portion 42 to apply the desired biasing force to the battery cell 20. In order to apply the desired biasing force from the first biasing portion 41 and the second biasing portion 42 to the battery cell 20, it is desirable to locate the first recessed portion 33A and the second recessed portion 33B between the positive electrode terminal 24 and the negative electrode terminal 25 in the width direction WD.

[0049] <Safety valve and smoke exhaust duct> The battery cell 20 also has a safety valve 27 that is set to rupture when the internal pressure reaches an abnormal level. The safety valve 27 is provided on the electrode surface 20A between the positive electrode terminal 24 and the negative electrode terminal 25. The safety valve 27 is configured, for example, by covering a hole in the end surface of the metal case of the battery cell 20 with a thin metal film. In this case, when the internal pressure of the battery cell 20 reaches an abnormal level, the metal film ruptures. The hole in the metal case is then opened, and the gas inside the battery cell 20 is released to the outside of the metal case. This reduces the internal cell pressure, making it possible to prevent the battery cell 20 from exploding.

[0050] In addition to the components described above, the top wall 33 also includes a smoke exhaust duct 50. The smoke exhaust duct 50 is provided on the outer surface 30B of the top wall 33. The smoke exhaust duct 50 extends in a U-shape away from the top wall 33. One end and the other end of the smoke exhaust duct 50 are connected to the outer surface 30B of the top wall 33. The ends of the smoke exhaust duct 50 that are away from the top wall 33 are located farther from the top wall 33 than the protruding tips of the first recessed portion 33A and the second recessed portion 33B.

[0051] In the battery module 10, the smoke exhaust duct 50 is arranged alongside the safety valve 27 in the thickness direction TD. In the battery module 10, the smoke exhaust duct 50 extends in the thickness direction TD away from the main surface 20C of the battery cell 20. The length of the smoke exhaust duct 50 in the thickness direction TD is longer than the length of the portion of the top wall 33 where the smoke exhaust duct 50 is provided in the thickness direction TD. The smoke exhaust duct 50 extends in the thickness direction TD away from the main body wall 31.

[0052] In the battery stack 100, the smoke exhaust duct 50 overlaps with the safety valve 27 of an adjacent battery module 10 in the height direction HD. In the battery stack 100, the battery modules 10 are stacked in the thickness direction TD, so that the smoke exhaust duct 50 extends in a tunnel-like manner in the thickness direction TD. In the battery stack 100, the smoke exhaust ducts 50 stacked in the thickness direction TD cover the safety valve 27 of each battery cell 20.

[0053] In the battery stack 100, gas generated from the battery cells 20 is passed through the internal spaces of multiple smoke exhaust ducts 50 that are connected in a tunnel-like manner in the thickness direction TD. In addition, the internal space of the smoke exhaust hose 110 is connected to the internal space of the smoke exhaust duct 50 of the battery module 10 provided at the end of the thickness direction TD. With this, even if gas is discharged from the safety valve 27, the gas is discharged to the outside through the internal spaces of the smoke exhaust duct 50 and the smoke exhaust hose 110.

[0054] The smoke exhaust duct 50 is provided in a portion of the top wall extension 33C between the first recessed portion 33A and the second recessed portion 33B. The smoke exhaust duct 50 and the first recessed portion 33A are connected in the width direction WD via a portion of the top wall extension 33C. The smoke exhaust duct 50 and the second recessed portion 33B are connected in the width direction WD via a portion of the top wall extension 33C. A small gap is generated between the top wall extension 33C between the smoke exhaust duct 50 and the first recessed portion 33A and the electrode surface 20A. This gap may be referred to as a first gap 51. A small gap is generated between the top wall extension 33C between the smoke exhaust duct 50 and the second recessed portion 33B and the electrode surface 20A. This gap may be referred to as a second gap 52. The first gap 51 and the second gap 52 are narrow enough to prevent the passage of gas discharged from the safety valve 27.

[0055] <Busbar case and recess> As described above, the busbar case 90 is attached to, for example, the battery case 70 so as to cover the electrode surfaces 20A of the multiple battery cells 20. The busbar case 90 is provided from one end of the battery case 70 along the thickness direction TD to hold the multiple busbars 80. The busbar case 90 has a first busbar holding wall 91, a second busbar holding wall 92, and a busbar holding connecting wall 93 that connects the first busbar holding wall 91 and the second busbar holding wall 92. The first busbar holding wall 91 holds the busbars 80 that are electrically connected to the electrode terminals 24, 25 provided at one end in the width direction WD. The second busbar holding wall 92 holds the busbars 80 that are electrically connected to the electrode terminals 24, 25 provided at the other end in the width direction WD. The first busbar holding wall 91 and the second busbar holding wall 92 each have a through hole 94 through which the electrode terminals 24, 25 pass.

[0056] The first busbar retaining wall 91 and the second busbar retaining wall 92 are provided closer to the top wall 33 in the height direction HD than the busbar retaining connecting wall 93. The busbar retaining connecting wall 93 extends in a U-shape so as to move away from the first busbar retaining wall 91 and the second busbar retaining wall 92 in the height direction HD. The busbar retaining connecting wall 93 is provided farther from the top wall 33 in the height direction HD than the first recessed portion 33A, the second recessed portion 33B, the top wall extension portion 33C, and the smoke exhaust duct 50.

[0057] In the height direction HD, the first busbar holding wall 91 and the second busbar holding wall 92 are provided farther away from the first recessed portion 33A and the second recessed portion 33B than the top wall 33. The busbar 80 is connected to the electrode terminals 24, 25 in a state in which the first busbar holding wall 91 and the second busbar holding wall 92 fix the busbar 80 from the electrode surface 20A side. In addition, in the width direction WD, the first busbar holding wall 91 is provided closer to the left sidewall 32 than the first recessed portion 33A. In the height direction HD, the first busbar holding wall 91 and the first recessed portion 33A do not overlap. In the width direction WD, the second busbar holding wall 92 is provided closer to the right sidewall 34 than the second recessed portion 33B. In the height direction HD, the second busbar holding wall 92 and the first recessed portion 33A do not overlap.

[0058] <Action and effect> The battery module 10 has battery cells 20 and a resin frame 30. The battery cells 20 are held in place by the resin frame 30. The resin frame 30 includes a main body wall 31, a left side wall 32 and a right side wall 34 spaced apart in the width direction WD, a top wall 33 and a bottom wall 35 spaced apart in the height direction HD, and a biasing portion 40. The top wall 33 is located higher than the electrode surface 20A. The top wall 33 extends in the width direction WD to connect the left side wall 32 and the right side wall 34. The biasing portion 40 includes a first biasing portion 41, a second biasing portion 42, and a third biasing portion 43. The first biasing portion 41 and the second biasing portion 42 are provided on the inner surface 30A of the top wall 33. The third biasing portion 43 is provided on the inner surface 30A of the right side wall 34.

[0059] The first urging portion 41 and the second urging portion 42 extend in the height direction HD toward the electrode surface 20A so as to move away from the inner surface 30A of the top wall 33. The tip portions of the first urging portion 41 and the second urging portion 42 are in contact with the electrode surface 20A. The first urging portion 41 and the second urging portion 42 urge the battery cell 20 toward the bottom wall 35. As the top wall 33 extends from the left side wall 32 toward the right side wall 34, the formation portions of the first urging portion 41 and the second urging portion 42 extend in a locally recessed manner in the height direction HD so as to move away from the bottom wall 35. The base portions of the first urging portion 41 and the second urging portion 42 are each locally surrounded by a portion of the top wall 33.

[0060] The third urging portion 43 extends in the width direction WD toward the side surface 20D so as to move away from the inner surface 30A of the right side wall 34. The tip of the third urging portion 43 is in contact with the side surface 20D of the battery cell 20. The third urging portion 43 urges the battery cell 20 toward the left side wall 32. As the right side wall 34 extends from the top wall 33 toward the bottom wall 35, the portion where the third urging portion 43 is formed extends in a locally recessed manner in the width direction WD so as to move away from the right side wall 34. The base of the third urging portion 43 is locally surrounded by a portion of the right side wall 34.

[0061] This prevents the overall size of the resin frame 30 from increasing compared to a configuration in which the entire resin frame 30 is offset to match the location of the biasing portion 40 in the resin frame 30. It has become possible to provide a battery module 10 including a resin frame 30 with a reduced increase in size.

[0062] The section modulus of first recessed portion 33A surrounding the base of first biasing portion 41 and the section modulus of second recessed portion 33B surrounding the base of second biasing portion 42 are higher than the section modulus of top wall extension 33C. The rigidity of first recessed portion 33A and second recessed portion 33B is higher than the rigidity of top wall extension 33C. First recessed portion 33A and second recessed portion 33B are less likely to deform in the height direction HD than top wall extension 33C.

[0063] As described above, the first urging portion 41 and the second urging portion 42 urge the battery cell 20 toward the bottom wall 35. As the first urging portion 41 and the second urging portion 42 urge the battery cell 20, a reaction force is generated from the battery cell 20 to the first urging portion 41 and the second urging portion 42. There is a concern that this reaction force may cause the first recessed portion 33A and the second recessed portion 33B to deform so as to move away from the battery cell 20.

[0064] However, in this embodiment, the rigidity of the first recessed portion 33A and the second recessed portion 33B is greater than the rigidity of the top wall extension portion 33C, so the first recessed portion 33A and the second recessed portion 33B are prevented from deforming so as to move away from the battery cell 20. This prevents an accompanying increase in the size of the resin frame 30.

[0065] A positive electrode terminal 24 and a negative electrode terminal 25 are provided on the electrode surface 20A. A portion of the top wall 33 is cut out to avoid the positive electrode terminal 24 and the negative electrode terminal 25. The positive electrode terminal 24 and the negative electrode terminal 25 are provided in the cutout 36. A first recess 33A and a second recess 33B are provided in the top wall 33 at a position aligned with the cutout 36. The first recess 33A and the second recess 33B protrude away from the top wall extension 33C.

[0066] Furthermore, the protruding tip ends of the positive electrode terminal 24 and the negative electrode terminal 25 are located farther from the electrode surface 20A than the protruding tip ends of the first recessed portion 33A and the second recessed portion 33B. This makes it possible to prevent the first recessed portion 33A and the second recessed portion 33B from deforming beyond the positive electrode terminal 24 and the negative electrode terminal 25, even if the first recessed portion 33A and the second recessed portion 33B are deformed by the reaction force so as to move away from the electrode surface 20A. This prevents the size of the resin frame 30 from increasing more than necessary.

[0067] The smoke exhaust duct 50 is provided between the first recessed portion 33A and the second recessed portion 33B in the width direction WD. The smoke exhaust duct 50 is provided in the top wall extension portion 33C at a portion connecting the first recessed portion 33A and the second recessed portion 33B. The first recessed portion 33A and the second recessed portion 33B protrude away from the top wall extension portion 33C. The smoke exhaust duct 50 extends in a U-shape away from the top wall 33. The tip of the smoke exhaust duct 50 away from the top wall 33 is located farther from the top wall 33 than the protruding tips of the first recessed portion 33A and the second recessed portion 33B. This makes it easier to prevent the first recessed portion 33A and the second recessed portion 33B from deforming beyond the smoke exhaust duct 50 due to a reaction force. This prevents the size of the resin frame 30 from increasing more than necessary.

[0068] In the battery stack 100, the battery modules 10 are stacked in the thickness direction TD, so that the smoke exhaust duct 50 extends in a tunnel-like manner in the thickness direction TD. The smoke exhaust ducts 50 stacked in the thickness direction TD cover the safety valves 27 of each battery cell 20. The gap between the electrode surface 20A and the portion of the top wall extension 33C between the first recessed portion 33A and the smoke exhaust duct 50 may be referred to as the first gap 51. The gap between the electrode surface 20A and the portion of the top wall extension 33C between the second recessed portion 33B and the smoke exhaust duct 50 may be referred to as the second gap 52. The first gap 51 and the second gap 52 are narrow enough to prevent the passage of gas discharged from the safety valve 27. This prevents gas from flowing into areas other than the internal space of the smoke exhaust duct 50 through the gap between the top wall extension 33C and the electrode surface 20A.

[0069] The tip end of the first urging portion 41 and the tip end of the second urging portion 42 are in contact with the electrode surface 20A of the battery cell 20. The first urging portion 41 and the second urging portion 42 urge the battery cell 20 toward the bottom wall 35. The lower surface 20B of the battery cell 20 is pressed against the inner surface 30A of the bottom wall 35. The lower surface 20B abuts against the inner surface 30A of the bottom wall 35, thereby defining the position of the battery cell 20 in the height direction HD. The tip end of the third urging portion 43 is in contact with the side surface 20D of the battery cell 20.

[0070] The third biasing portion 43 biases the battery cell 20 toward the left side wall 32. The side surface 20D is pressed against the inner surface 30A of the left side wall 32. The side surface 20D is in contact with the inner surface 30A of the left side wall 32. The side surface 20D abuts against the inner surface 30A of the left side wall 32, thereby defining the position of the battery cell 20 in the width direction WD. This defines the positions of the battery cell 20 in the width direction WD and height direction HD.

[0071] The first urging portion 41 and the second urging portion 42 extend in the height direction HD toward the electrode surface 20A, moving away from the inner surface 30A of the top wall 33. The first urging portion 41 and the second urging portion 42 extend away from each other in the width direction WD. The third urging portion 43 extends in the width direction WD toward the side surface 20D, moving away from the inner surface 30A of the right side wall 34. The third urging portion 43 extends closer to the electrode surface 20A as it moves away from the inner surface 30A of the right side wall 34 in the width direction WD. This makes it easier to prevent the position of the battery cell 20 from shifting in the height direction HD and the width direction WD. The position of the battery cell 20 is defined.

[0072] The busbar case 90 has a first busbar holding wall 91, a second busbar holding wall 92, and a busbar holding connecting wall 93. The first busbar holding wall 91 and the second busbar holding wall 92 are provided closer to the top wall 33 in the height direction HD than the busbar holding connecting wall 93. In the height direction HD, the first busbar holding wall 91 and the second busbar holding wall 92 are provided farther away from the top wall 33 than the first recessed portion 33A and the second recessed portion 33B. In the width direction WD, the first busbar holding wall 91 is provided closer to the left side wall 32 than the first recessed portion 33A. In the height direction HD, the first busbar holding wall 91 and the first recessed portion 33A do not overlap each other.

[0073] In the width direction WD, the second busbar holding wall 92 is provided closer to the right side wall 34 than the second recessed portion 33B. In the height direction HD, the second busbar holding wall 92 and the second recessed portion 33B do not overlap. This makes it easier to prevent the first recessed portion 33A and the second recessed portion 33B from coming into contact with and pushing up the first busbar holding wall 91 and the second busbar holding wall 92, even if the first recessed portion 33A and the second recessed portion 33B are deformed away from the top wall 33 by a reaction force. This prevents the size of the battery stack 100 from increasing more than necessary.

[0074] (Second embodiment) Fig. 8 is a perspective view of a battery module 10 of the second embodiment. Figs. 9 and 10 are cross-sectional views of the battery module 10 of the second embodiment. In the battery module 10 of the first embodiment, a configuration has been described in which the smoke exhaust duct 50 extends away from one of the main surfaces 20C of the battery cells 20 in the thickness direction TD. In the battery stack 100 of the first embodiment, a configuration has been described in which the smoke exhaust duct 50 overlaps with the safety valve 27 of an adjacent battery module 10 in the height direction HD. However, the configurations of the battery module 10 and the battery stack 100 are not limited to this.

[0075] In the battery module 10 of the second embodiment, the smoke exhaust duct 50 extends in the thickness direction TD so as to move away from another one of the main surfaces 20C of the battery cells 20. In the battery module 10 and battery stack 100 of the second embodiment, in one battery module 10, the smoke exhaust duct 50 overlaps with the safety valve 27 in the height direction HD. This also achieves the same effects as the first embodiment.

[0076] (Third embodiment) 10 and 11 are cross-sectional views of a battery module 10 according to a third embodiment. In the battery module 10 of the third embodiment, the resin frame 30 does not include side walls 32, 34. In other words, the resin frame 30 of the third embodiment includes a main body wall 31, a top wall 33, a bottom wall 35, a first urging portion 41, a second urging portion 42, and a smoke exhaust duct 50. The first urging portion 41 and the second urging portion 42 are provided in the top wall 33. A first recessed portion 33A and a second recessed portion 33B are provided in the top wall 33. In the third embodiment, the top wall 33 extends along the electrode surface 20A. The bottom wall 35 extends along at least a portion of the lower surface 20B.

[0077] (Fourth embodiment) FIG. 12 is a cross-sectional view of a battery module 10 according to a fourth embodiment. In the battery module 10 according to the fourth embodiment, the resin frame 30 does not include side walls 32 and 34. In other words, the resin frame 30 according to the fourth embodiment includes a main body wall 31, a top wall 33, a bottom wall 35, a first urging portion 41, a second urging portion 42, and a smoke exhaust duct 50. In the fourth embodiment, the first urging portion 41 is provided on the top wall 33. The second urging portion 42 is provided on the bottom wall 35. A first recessed portion 33A is provided on the top wall 33 so as to surround the base of the first urging portion 41. A second recessed portion 33B is provided on the bottom wall 35 so as to surround the base of the second urging portion 42. In the fourth embodiment, the second recessed portion 33B is locally recessed and extends away from the top wall 33 in the height direction HD.

[0078] (Fifth embodiment) 13 is a cross-sectional view of a battery module 10 according to a fifth embodiment. In the battery module 10 of the fifth embodiment, the resin frame 30 does not include a top wall 33 or a bottom wall 35. In other words, the resin frame 30 of the fifth embodiment includes a main body wall 31, a left side wall 32, a right side wall 34, a third urging portion 43, and a fourth urging portion 44. The third urging portion 43 is provided on the right side wall 34. The fourth urging portion 44 is provided on the opposing wall 32.

[0079] As the right side wall 34 extends from the top wall 33 toward the bottom wall 35, the right side wall 34 is locally offset in the width direction WD at the formation portion of the third urging portion 43 so as to move away from the left side wall 32. In other words, as the right side wall 34 extends from the top wall 33 toward the bottom wall 35, the formation portion of the third urging portion 43 extends in a recessed manner so as to move away from the left side wall 32 in the width direction WD.

[0080] For this reason, the base of the third urging portion 43 is surrounded by a portion of the right side wall 34. The portion of the right side wall 34 surrounding the base of the third urging portion 43 is sometimes referred to as the third recessed portion 34A. The portion of the right side wall 34 connected to the third recessed portion 34A is sometimes referred to as the right-side extended portion 34B. The right side wall 34 has the third recessed portion 34A and the right-side extended portion 34B. One end of the top wall 33 and the third recessed portion 34A is connected by a portion of the right-side extended portion 34B. The other end of the third recessed portion 34A and the bottom wall 35 are connected by a portion of the right-side extended portion 34B. Furthermore, because the third recessed portion 34A is bent to surround the base of the third biasing portion 43, the section modulus of the third recessed portion 34A is higher than the section modulus of the right-side extending portion 34B. The rigidity of the third recessed portion 34A is higher than the rigidity of the right-side extending portion 34B. The third recessed portion 34A is less likely to deform in the width direction WD than the right-side extending portion 34B. This also achieves the same effects as the first embodiment.

[0081] Similarly, the left side wall 32, as it extends from the top wall 33 toward the bottom wall 35, is locally offset in the width direction WD at the formation portion of the fourth urging portion 44 so as to move away from the right side wall 34. In other words, as the left side wall 32 extends from the top wall 33 toward the bottom wall 35, the formation portion of the fourth urging portion 44 extends in a recessed manner so as to move away from the right side wall 34 in the width direction WD.

[0082] For this reason, the base of the fourth urging portion 44 is surrounded by a portion of the left side wall 32. The locally recessed portion of the left side wall 32 where the fourth urging portion 44 is formed may be referred to as the fourth recessed portion 32A. The portion of the left side wall 32 connected to the fourth recessed portion 32A may be referred to as the left-side extension portion 32B. The left side wall 32 has the fourth recessed portion 32A and the left-side extension portion 32B. The top wall 33 and one end of the fourth recessed portion 32A are connected by a portion of the left-side extension portion 32B. The other end of the fourth recessed portion 32A and the bottom wall 35 are connected by a portion of the left-side extension portion 32B.

[0083] Furthermore, because the fourth recessed portion 32A is bent to surround the base of the fourth biasing portion 44, the section modulus of the fourth recessed portion 32A is higher than the section modulus of the left-side extending portion 32B. The rigidity of the fourth recessed portion 32A is higher than the rigidity of the left-side extending portion 32B. The fourth recessed portion 32A is less likely to deform in the width direction WD than the left-side extending portion 32B. This also achieves the same effects as the first embodiment.

[0084] (Sixth embodiment) 14 is a cross-sectional view of a battery module 10 according to the sixth embodiment. The resin frame 30 in the sixth embodiment includes a main body wall 31, a left side wall 32, a top wall 33, a right side wall 34, a bottom wall 35, a first urging portion 41, a second urging portion 42, and a fourth urging portion 44. The battery module 10 of the sixth embodiment does not include the third urging portion 43. The first urging portion 41 is provided on the top wall 33. The second urging portion 42 is provided on the bottom wall 35. The fourth urging portion 44 is provided on the left side wall 32. The recessed portions corresponding to the urging portions 40 extend in a recessed manner so as to be locally away from the opposing wall. This also achieves the same effects as the first embodiment.

[0085] Seventh embodiment 15 is a cross-sectional view of a battery module 10 according to the seventh embodiment. The resin frame 30 according to the seventh embodiment includes a main body wall 31, a left side wall 32, a top wall 33, a right side wall 34, a bottom wall 35, a first urging portion 41, a second urging portion 42, a third urging portion 43, and a fourth urging portion 44. The first urging portion 41 and the second urging portion 42 are provided on the top wall 33. The third urging portion 43 is provided on the right side wall 34. The fourth urging portion 44 is provided on the left side wall 32. The recessed portions corresponding to the urging portions 40 extend in a recessed manner so as to be locally away from the opposing wall. This also achieves the same effect.

[0086] (Other embodiments) For ease of explanation, the first recessed portion 33A, the second recessed portion 33B, the third recessed portion 34A, and the fourth recessed portion 32A may be collectively referred to as recessed portion 30C. FIGS. 16 to 20 show other embodiments of recessed portion 30C. As shown in FIG. 16, recessed portion 30C may be U-shaped at a substantially right angle. As shown in FIG. 17, the thickness of the recessed portion 30C at the location where the biasing portion 40 is formed may be locally thick. As shown in FIG. 18, recessed portion 30C may be U-shaped with a curved shape. As shown in FIG. 19, recessed portion 30C may be U-shaped with a substantially right-angled corner at one end. As shown in FIG. 20, recessed portion 30C may be V-shaped.

[0087] 21 to 26 show other embodiments of the urging portion 40. As shown in FIG. 21, the urging portion 40 may have a rib shape extending in one direction. As shown in FIG. 22, the urging portion 40 may have a rib shape with a pointed tip. When the urging portion 40 has a pointed tip, the tip may be crushed as shown in FIG. 23 when pressed against the battery cell 20. As shown in FIG. 24, the urging portion 40 may have a rib shape that extends in one direction while bending. As shown in FIG. 25, the urging portion 40 may have a plurality of rib shapes extending in one direction. As shown in FIG. 26, the lengths of the plurality of rib shapes may be different.

[0088] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more, or less are also within the scope and spirit of the present disclosure.

[0089] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be written in a multiple dependent form, with subsequent clauses alternatively referencing preceding clauses. Some clauses may be written in a multiple dependent form, with subsequent clauses alternatively referencing preceding clauses. These multiple dependent clauses define multiple technical ideas.

[0090] (Technical thought 1) A rectangular battery cell (20) that is flat in the thickness direction (TD), a frame (30) that holds the battery cells; The frame is a plate-shaped main body wall (31) that overlaps the battery cell in the thickness direction; a pair of opposing walls (32, 33, 34, 35) provided at both ends of the main body wall in a direction different from the thickness direction and extending in the thickness direction so as to face the battery cells; a biasing portion (41, 42, 43) provided on an inner surface (30A) of at least one of the pair of opposing walls, extending toward the battery cell and biasing the battery cell; A battery module in which the target wall on which the biasing portion is provided, of the pair of opposing walls, has a recessed portion (32A, 33A, 33B, 34A) that is locally recessed so as to move away from the battery cell at the location where the biasing portion is provided.

[0091] (Technical thought 2) The battery module according to Technical Idea 1, wherein the recessed portion has a rigidity higher than that of an extension (33C, 32B, 34B) continuing from the recessed portion in the target wall.

[0092] (Technical Thought 3) The battery cell includes electrode terminals (24, 25) and an electrode surface (20A) on which the electrode terminals are provided, the target wall is provided to face the electrode surface in a height direction (HD), A notch (36) is formed in the target wall to expose the electrode terminal, The battery module according to Technical Idea 1 or 2, wherein the electrode terminal is exposed from the notch and extends farther from the electrode surface than the recessed portion.

[0093] (Technical Thought 4) The target wall further includes a tunnel-shaped exhaust duct (50) extending away from the electrode surface and penetrating in the thickness direction to exhaust gas discharged from the battery cells, The battery module according to Technical Idea 3, wherein the end of the smoke exhaust duct is located farther from the electrode surface than the recess in the height direction.

[0094] (Technical Thought 5) a part of the extension portion is provided between the recessed portion and the smoke exhaust duct; A battery module according to Technical Idea 4, wherein the gap between the electrode surface and the portion of the extension between the recess and the smoke exhaust duct is narrow enough to prevent the gas from flowing.

[0095] (Technical Thought 6) The frame has two pairs of the opposing walls, First opposing walls (33, 35), which are one of the two opposing walls, are provided at both ends of the main body wall in the height direction, a second pair of opposing walls (32, 34) that is another pair of the two pairs of opposing walls is provided at both ends of the main body wall in the width direction (WD) of the battery cell; the first opposing wall includes a first side wall (33) that faces the electrode surface in the height direction as one of the target walls, first target biasing portions (41, 42) that extend from the first side wall toward the electrode surface and bias the battery cell in a direction away from the first side wall in the height direction, and a second side wall (35) against which the battery cell is pressed by the first target biasing portion; A battery module described in any one of technical ideas 3 to 5, wherein the second opposing wall is another of the target walls and includes a third side wall (34) that faces the side surface (20D) of the battery cell in the width direction, a second target biasing portion (43) that extends from the third side wall toward the battery cell and biases the battery cell in a direction away from the third side wall in the width direction, and a fourth side wall (32) against which the battery cell is pressed by the second target biasing portion.

[0096] (Technical Thought 7) two first target biasing portions; two first target biasing portions are provided on the inner surface of the first side wall, spaced apart in the width direction; The battery module according to Technical Idea 6, wherein the two first target biasing portions extend so as to move away from each other as they approach the electrode surface.

[0097] (Technical Thought 8) The second target biasing portion is provided, the second target biasing portion is provided on the inner surface of the third side wall, The battery module according to Technical Idea 6 or 7, wherein the second target biasing portion extends toward the electrode surface as it approaches the side surface.

[0098] (Technical Thought 9) a plurality of battery modules (10) stacked in a thickness direction (TD), each of which has a rectangular battery cell (20) that is flat in the thickness direction (TD) and a frame (30) that holds the battery cell; a bus bar (80) electrically connected to the plurality of battery cells; bus bar holding walls (91, 92) that hold the bus bars, The frame is a plate-shaped main body wall (31) that overlaps the battery cell in the thickness direction; a pair of opposing walls (32, 33, 34, 35) provided at both ends of the main body wall in a direction different from the thickness direction and extending in the thickness direction so as to face the battery cells; a biasing portion (41, 42, 43) provided on an inner surface (30A) of at least one of the pair of opposing walls, extending toward the battery cell and biasing the battery cell; A battery stack in which the target wall on which the biasing portion is provided, of the pair of opposing walls, has a recessed portion (32A, 33A, 33B, 34A) that is locally recessed so as to move away from the battery cell at the location where the biasing portion is provided.

[0099] (Technical Thought 10) The battery cell includes electrode terminals (24, 25) and an electrode surface (20A) on which the electrode terminals are provided, the target wall is provided to face the electrode surface in a height direction (HD), A notch (36) is formed in the target wall to expose the electrode terminal, the electrode terminal is exposed from the notch and extends farther from the electrode surface than the recessed portion; the recessed portion and the electrode terminal are spaced apart in the width direction (WD) of the battery cell, the bus bar is connected to the electrode terminal in a state where it is fixed from the electrode surface side by the bus bar holding wall, The battery stack according to Technical Idea 9, wherein the bus bar holding wall and the recessed portion do not overlap in the height direction. [Explanation of symbols]

[0100] 10 battery module, 20 battery cell, 20A electrode surface, 20D side surface, 24, 25 electrode terminal, 30 frame, 30A inner surface, 31 main body wall, 32 second opposing wall, 32 fourth side wall, 32A recessed portion, 32B extension portion, 33 first opposing wall, 33 first side wall, 33A, 33B recessed portion, 33C extension portion, 34 second opposing wall, 34 third side wall, 34A recessed portion, 34B extension portion, 35 first opposing wall, 35 second side wall, 36 notch, 41 first target urging portion, 41, 42 urging portion, 42 first target urging portion, 42, 43 urging portion, 43 second target urging portion, 50 Smoke exhaust duct, 80 busbar, 91, 92 busbar retaining wall, HD height direction, TD thickness direction, WD width direction.

Claims

1. A rectangular battery cell (20) that is flat in the thickness direction (TD), a frame (30) that holds the battery cells; The frame is a plate-shaped main body wall (31) overlapping the battery cell in the thickness direction; a pair of opposing walls (32, 33, 34, 35) provided at both ends of the main body wall in a direction different from the thickness direction and extending in the thickness direction so as to face the battery cells; a biasing portion (41, 42, 43) provided on an inner surface (30A) of at least one of the pair of opposing walls, extending toward the battery cell and biasing the battery cell; a target wall of the pair of opposing walls on which the biasing portion is provided includes a recessed portion (32A, 33A, 33B, 34A) that is locally recessed so as to move away from the battery cell at a location where the biasing portion is provided, The battery module has a rigidity of the recessed portion higher than a rigidity of an extension portion (33C, 32B, 34B) continuing from the recessed portion in the target wall.

2. The battery cell includes electrode terminals (24, 25) and an electrode surface (20A) on which the electrode terminals are provided, the target wall is provided to face the electrode surface in a height direction (HD), a notch (36) for exposing the electrode terminal is formed in the target wall; The battery module according to claim 1 , wherein the electrode terminal is exposed from the notch and extends farther from the electrode surface than the recess.

3. The target wall further includes a tunnel-shaped exhaust duct (50) extending away from the electrode surface and penetrating in the thickness direction to exhaust gas discharged from the battery cell, The battery module according to claim 2 , wherein an end of the smoke exhaust duct is provided farther from the electrode surface than the recess in the height direction.

4. a part of the extension portion is provided between the recessed portion and the smoke exhaust duct; 4. The battery module according to claim 3, wherein a gap between the electrode surface and a portion of the extension between the recess and the smoke exhaust duct is narrow enough to prevent the gas from flowing.

5. The frame has two pairs of the opposing walls, First opposing walls (33, 35) that are one of the two opposing walls are provided at both ends of the main body wall in the height direction, a second pair of opposing walls (32, 34) that is another pair of the two pairs of opposing walls is provided at both ends of the main body wall in the width direction (WD) of the battery cell; the first opposing wall includes a first side wall (33) that faces the electrode surface in the height direction as one of the target walls, a first target biasing portion (41, 42) that extends from the first side wall toward the electrode surface and biases the battery cell in a direction away from the first side wall in the height direction, and a second side wall (35) against which the battery cell is pressed by the first target biasing portion; The battery module according to any one of claims 2 to 4, wherein the second opposing wall comprises a third side wall (34) that faces the side surface (20D) of the battery cell in the width direction as another of the target walls, a second target biasing portion (43) that extends from the third side wall toward the battery cell and biases the battery cell in a direction away from the third side wall in the width direction, and a fourth side wall (32) against which the battery cell is pressed by the second target biasing portion.

6. two first target biasing portions; two first target biasing portions are provided on the inner surface of the first side wall, spaced apart in the width direction; The battery module according to claim 5 , wherein the two first target biasing portions extend so as to move away from each other as they approach the electrode surface.

7. The second target biasing portion is provided as one, the second target biasing portion is provided on the inner surface of the third side wall, The battery module according to claim 6 , wherein the second target biasing portion extends toward the electrode surface as it approaches the side surface.

8. a plurality of battery modules (10) each having a rectangular battery cell (20) that is flat in a thickness direction (TD) and a frame (30) that holds the battery cell, the battery modules (10) being stacked in the thickness direction; a bus bar (80) electrically connected to the plurality of battery cells; bus bar holding walls (91, 92) that hold the bus bars, The frame is a plate-shaped main body wall (31) overlapping the battery cell in the thickness direction; a pair of opposing walls (32, 33, 34, 35) provided at both ends of the main body wall in a direction different from the thickness direction and extending in the thickness direction so as to face the battery cells; a biasing portion (41, 42, 43) provided on an inner surface (30A) of at least one of the pair of opposing walls, extending toward the battery cell and biasing the battery cell; a target wall of the pair of opposing walls on which the biasing portion is provided includes a recessed portion (32A, 33A, 33B, 34A) that is locally recessed so as to move away from the battery cell at a location where the biasing portion is provided, A battery stack in which the rigidity of the recessed portion is higher than the rigidity of an extension portion (33C, 32B, 34B) continuing from the recessed portion in the target wall.

9. The battery cell includes electrode terminals (24, 25) and an electrode surface (20A) on which the electrode terminals are provided, the target wall is provided to face the electrode surface in a height direction (HD), a notch (36) for exposing the electrode terminal is formed in the target wall; the electrode terminal is exposed from the notch and extends farther from the electrode surface than the recessed portion; the recessed portion and the electrode terminal are spaced apart in the width direction (WD) of the battery cell, the bus bar is connected to the electrode terminal in a state where it is fixed from the electrode surface side by the bus bar holding wall, The battery stack according to claim 8 , wherein the bus bar holding wall and the recessed portion do not overlap with each other in the height direction.

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