Battery, bonding jig, bonding device, and method for manufacturing a battery

Abstract

To provide a battery in which a proper connection can be ensured at the joint portion between the lead and the current collector portion, at a portion adjacent to the side opposite to the side on which the current collector portion protrudes relative to the recessed structure. [Solution] The battery of the embodiment comprises an electrode group, leads, a groove, and a recessed structure. The electrode group includes a current-collecting flux portion that protrudes to one side in the longitudinal direction. The leads are joined to the current-collecting flux portion in a state where they are stacked on top of the electrode group from one side in the thickness direction intersecting the longitudinal direction. The groove is recessed to the bottom of the groove on the side where the leads are located in the thickness direction at the joining portion of the leads and the current-collecting flux portion. The recessed structure comprises one or more recesses that are further recessed from the bottom of the groove toward the side where the leads are located, and the bottom of the groove is adjacent to the recessed structure from the side opposite to the side where the current-collecting flux portion protrudes in the longitudinal direction.

Description

Technical Field

[0001] Embodiments of the present invention relate to a battery, a bonding jig, a bonding device, and a method for manufacturing a battery.

Background Art

[0002] A battery such as a lithium-ion secondary battery includes an electrode group, and the electrode group includes a positive electrode and a negative electrode. In the electrode group, each of the positive electrode and the negative electrode includes a current collector, and in the current collector, a current collecting bundle portion in which a plurality of current collecting band portions are bundled is formed. In the electrode group, the current collecting bundle portion protrudes toward one side in the length direction, and in the battery, the current collecting bundle portion of the current collector is electrically connected to a terminal via a lead or the like. The current collecting bundle portion is joined to the lead by ultrasonic welding or the like, and in the battery, a joined portion of the current collecting bundle portion and the lead is formed.

[0003] In the manufacture of a battery, joining of the current collecting bundle portion to the lead is performed using a bonding jig in which one or more protrusions of a convex structure portion protrude. In the joining of the current collecting bundle portion to the lead, the lead is stacked on the current collecting bundle portion from one side in the thickness direction of the electrode group, and the joined target portion where the current collecting bundle portion and the lead are stacked is sandwiched between the bonding jig and the stage. Then, in a state where the joined target portion is sandwiched between the bonding jig and the stage, for example, ultrasonic vibration is transmitted to the joined target portion through the bonding jig, and the lead and the current collecting bundle portion are joined. In a state where the joining of the joined target portion is being performed, one or more protrusions of the convex structure portion are brought into contact with the joined target portion from the side opposite to the side where the lead is stacked. Therefore, in the joined portion where the lead and the current collecting bundle portion are joined, a recess is formed in each of the portions where one or more protrusions are in contact, recessing toward the side where the lead is located, and a concave structure portion is formed by the one or more recesses.

[0004] As described above, when joining the current-collecting flux section to the lead, it is required to ensure proper joining of the lead and the current-collecting flux section at the joining portion. In particular, it is required to ensure proper joining at the portion adjacent to the side opposite to the side from which the current-collecting flux section protrudes relative to the recessed structure. For example, at the joining portion of the lead and the current-collecting flux section, it is required to appropriately suppress the bending of the current-collecting flux section toward the side opposite to the side in the thickness direction where the lead is located at the portion adjacent to the side opposite to the side from which the current-collecting flux section protrudes relative to the recessed structure. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-126822 [Overview of the project] [Problems that the invention aims to solve]

[0006] The problem that the present invention aims to solve is to provide a battery, a joining jig, a joining device, and a method for manufacturing a battery that can properly ensure a joint at the joint portion between the lead and the current collector portion, at a portion adjacent to the side opposite to the side on which the current collector portion protrudes relative to the recessed structure. [Means for solving the problem]

[0007] According to the embodiment, the battery comprises an electrode group, leads, a groove, and a recessed structure, the electrode group having a current-collecting flux portion that protrudes to one side in the longitudinal direction. The leads are conductive and are joined to the current-collecting flux portion in a state where they are stacked on top of the electrode group from one side in the thickness direction of the electrode group, which intersects the longitudinal direction of the electrode group. The groove has a groove bottom and, at the joint portion between the leads and the current-collecting flux portion, is recessed to the groove bottom on the side where the leads are located in the thickness direction. The recessed structure comprises one or more recesses that are further recessed from the groove bottom of the groove toward the side where the leads are located, and the groove bottom of the groove is adjacent to the recessed structure from the side opposite to the side where the current-collecting flux portion protrudes in the longitudinal direction. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing an example of the battery configuration according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram showing an example of the configuration of the electrode group in the battery according to the first embodiment. [Figure 3] Figure 3 is a schematic diagram showing an example of the configuration of the connection portion of one current-collecting flux portion of an electrode group to a lead, and its vicinity, as viewed from one side in the thickness direction of the electrode group, in a battery according to the first embodiment. [Figure 4] Figure 4 is a schematic cross-sectional view showing a cross-section along the dashed line A1 in Figure 3. [Figure 5] Figure 5 is a schematic cross-sectional view showing a cross-section along the dashed line A2 in Figure 3. [Figure 6] Figure 6 is a schematic diagram showing an example of the configuration of a bonding device used in the manufacture of a battery in the first embodiment. [Figure 7] Figure 7 is a schematic perspective view showing an example of the configuration of the joining tip portion of the joining jig according to the first embodiment. [Figure 8] Figure 8 is a schematic diagram showing an example of a state in the first embodiment where one current-collecting portion of an electrode group is joined to a lead, in a cross-section perpendicular or substantially perpendicular to the width direction of the electrode group. [Figure 9] Figure 9 is a schematic diagram showing the state in Figure 8 in a cross-section perpendicular or nearly perpendicular to the longitudinal direction of the electrode group. [Figure 10] Figure 10 is a schematic diagram showing an example of the configuration of the connection portion to the lead of one of the electrode group's current-collecting flux sections, and its vicinity, in a battery according to the first modified example. [Figure 11] Figure 11 is a schematic diagram showing an example of the configuration of the connection portion to the lead of one of the electrode group's current-collecting flux sections, and its vicinity, in a battery according to the second modified example. [Figure 12]Figure 12 is a schematic diagram showing an example of the configuration of the connection portion to the lead of one of the electrode group's current-collecting fluxes, and its vicinity, in a battery according to the third modified example, as viewed from one side in the thickness direction of the electrode group. [Figure 13] Figure 13 is a schematic cross-sectional view showing a section along the dashed line A3 in Figure 12. [Figure 14] Figure 14 is a schematic perspective view showing an example of the configuration of the joining tip portion of the joining jig according to the third modified example. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings.

[0010] (First Embodiment) Figure 1 is a schematic diagram showing an example of the configuration of a battery 1 according to the first embodiment. The battery 1 in the example in Figure 1 comprises an electrode group 2 and an outer casing 3. The outer casing 3 comprises an outer container 5 and a lid member 6. Here, the battery 1 and outer casing 3 are defined by a depth direction (a direction perpendicular or approximately perpendicular to the plane of the paper in Figure 1), a lateral direction (indicated by arrow Y) that intersects (orthogonal or approximately perpendicular to) the depth direction, and a height direction (indicated by arrow Z) that intersects (orthogonal or approximately perpendicular to) both the depth direction and the lateral direction. In each of the battery 1 and outer casing 3, the dimensions along the depth direction are smaller than the dimensions along the lateral direction and the dimensions along the height direction, respectively. Note that Figure 1 shows a cross-section perpendicular or approximately perpendicular to the depth direction.

[0011] The outer container 5 comprises a bottom wall 7 and a peripheral wall 8. Inside the outer container 5, an internal cavity 10 in which the electrode group 2 is housed is defined by the bottom wall 7 and the peripheral wall 8. In the outer container 5, the internal cavity 10 opens toward the side opposite to the side where the bottom wall 7 is located in the height direction. The lid member 6 is attached to the peripheral wall 8 at the end opposite to the bottom wall 7. Therefore, the lid member 6 closes the opening of the internal cavity 10 of the outer container 5. The lid member 6 and the bottom wall 7 face each other with the internal cavity 10 in between.

[0012] The electrode group 2 includes a positive electrode and a negative electrode. In the electrode group 2, a separator is interposed between the positive electrode and the negative electrode. In the electrode group 2, the separator is formed of a material having electrical insulation properties and electrically insulates the positive electrode from the negative electrode. In the electrode group 2, the positive electrode includes a positive electrode current collector such as a positive electrode current collecting foil and a positive electrode active material-containing layer coated (supported) on the surface of the positive electrode current collector. And the positive electrode current collector includes an uncoated portion 11 where the positive electrode active material-containing layer is not coated (not supported). Also, in the electrode group 2, the negative electrode includes a negative electrode current collector such as a negative electrode current collecting foil and a negative electrode active material-containing layer coated (supported) on the surface of the negative electrode current collector. And the negative electrode current collector includes an uncoated portion 11 where the negative electrode active material-containing layer is not coated (not supported). Due to the configuration as described above, in the electrode group 2, the uncoated portion 11 of the positive electrode and the uncoated portion 11 of the negative electrode are formed as a pair of uncoated portions 11. Note that the uncoated portion 11 of the positive electrode is also referred to as the "positive electrode uncoated portion", and the uncoated portion 11 of the negative electrode is also referred to as the "negative electrode uncoated portion".

[0013] FIG. 2 is a schematic diagram showing an example of the configuration of the electrode group 2 in the battery 1 according to the first embodiment. As shown in FIGS. 1 and 2, in the electrode group 2, a length direction (the directions indicated by arrows L1 and L2), a width direction (the direction indicated by arrow W) that intersects (is orthogonal or substantially orthogonal) to the length direction, and a thickness direction (the directions indicated by arrows C1 and C2) that intersects (is orthogonal or substantially orthogonal) to both the length direction and the width direction are defined. In the electrode group 2, the dimension along the thickness direction is smaller than each of the dimensions along the length direction and the dimension along the width direction. Note that in FIG. 1, the electrode group 2 is shown in a state viewed from one side in the thickness direction, and in FIG. 2, the electrode group 2 is shown in a cross section orthogonal or substantially orthogonal to the width direction.

[0014] In one example, electrode group 2 is formed in a so-called wound structure, where the positive electrode, negative electrode, and separator are wound around a winding axis with a separator interposed between them. In this case, the winding axis of the wound structure in electrode group 2 is aligned along the length direction of electrode group 2. In another example, electrode group 2 is formed in a so-called stack structure, where multiple positive electrode plates and multiple negative electrode plates are alternately stacked in the thickness direction of electrode group 2. In this case, the positive electrode is composed of multiple positive electrode plates, and the negative electrode is composed of multiple negative electrode plates. Multiple positive electrode plates and multiple negative electrode plates are stacked with a separator interposed between adjacent positive electrode plates in the thickness direction (stacking direction).

[0015] In the internal cavity 10, the electrode group 2 is held (impregnated) with an electrolyte (not shown). The electrolyte may be an aqueous solution or other water-based electrolyte, or a non-aqueous electrolyte obtained by dissolving the electrolyte in an organic solvent. Alternatively, a gel-like electrolyte or a solid electrolyte may be used instead of the electrolyte. When a solid electrolyte is used, the separator in the electrode group 2 may be formed from the solid electrolyte. Furthermore, a gas release valve and an electrolyte inlet may be formed in the lid member 6 of the outer casing 3. In this case, a sealing plate that closes the electrolyte inlet is welded to the outer surface of the lid member 6. Note that the gas release valve and electrolyte inlet, etc., do not necessarily have to be provided in the battery 1.

[0016] In an example of FIGS. 1 and 2, in the electrode group 2, the uncoated positive electrode portion (the uncoated portion 11 of the positive electrode) protrudes toward one side in the length direction of the electrode group 2. And in the electrode group 2, the uncoated negative electrode portion (the uncoated portion 11 of the negative electrode) protrudes toward the side opposite to the side where the uncoated positive electrode portion in the length direction protrudes. A current collecting bundle portion 12 is formed on each of the pair of uncoated portions 11. In an example of FIGS. 1 and 2, one current collecting bundle portion 12 is formed on each of the uncoated positive electrode portion and the uncoated negative electrode portion. Each of the current collecting bundle portions 12 includes a plurality of current collecting strip portions 13. And in each of the current collecting bundle portions 12, the plurality of current collecting strip portions 13 are bundled in a state of being stacked in the thickness direction of the electrode group 2. For this reason, the stacking direction of the current collecting strip portions 13 in each of the current collecting bundle portions 12 coincides with or substantially coincides with the thickness direction of the electrode group 2.

[0017] In the current collecting bundle portion 12 of the uncoated positive electrode portion, each of the plurality of current collecting strip portions 13 to be bundled is formed from a positive electrode current collector. And in the current collecting bundle portion 12 of the uncoated negative electrode portion, each of the plurality of current collecting strip portions 13 to be bundled is formed from a negative electrode current collector. In the electrode group 2, the current collecting bundle portion 12 of the uncoated positive electrode portion protrudes toward one side in the length direction, and the current collecting bundle portion 12 of the uncoated negative electrode portion protrudes toward the side opposite to the side where the uncoated positive electrode portion in the length direction protrudes.

[0018] In the battery 1 of an example of FIG. 1, the electrode group 2 is housed in the internal cavity 10 in a state where the thickness direction of the electrode group 2 is along the depth direction of the battery 1 and the length direction of the electrode group 2 is along the lateral direction of the battery 1. And the electrode group 2 is arranged in the internal cavity 10 in a state where the width direction of the electrode group 2 is along the height direction of the battery 1. Since the electrode group 2 is arranged in the internal cavity 10 in this way, in the battery 1 of an example of FIG. 1, the current collecting bundle portion 12 of the uncoated positive electrode portion protrudes toward one side in the lateral direction, and the current collecting bundle portion 12 of the uncoated negative electrode portion protrudes toward the side opposite to the side where the uncoated positive electrode portion in the lateral direction protrudes.

[0019] In the example battery 1 shown in Figure 1, a pair of terminals 15 are attached to the lid member 6. Each of the pair of terminals 15 is exposed to the outside of the battery 1 and is positioned on the outer surface of the lid member 6. The terminals 15 are made of a conductive material such as metal. One of the pair of terminals 15 becomes the positive terminal of the battery 1, and the other of the pair of terminals 15 becomes the negative terminal of the battery 1. In the example shown in Figure 1, an insulating member 16 is placed between each of the pair of terminals 15 and the lid member 6 on the outer surface of the lid member 6. Each of the pair of terminals 15 is electrically insulated from the outer casing 5 and the outer casing 3, including the lid member 6, by the insulating member 16.

[0020] In the example shown in Figure 1, a pair of leads 17 are housed in the internal cavity 10 of the outer casing 3. Each of the leads 17 is made of a conductive material and is conductive. One of the pair of leads 17 becomes the positive lead, and the other lead 17 becomes the negative lead. In battery 1, the positive terminal is connected to the positive lead, and the negative terminal is connected to the negative lead. In battery 1, the current-collecting flux portion 12 of the unpainted portion of the positive electrode is joined (connected) to the positive lead, and is electrically connected to the positive terminal via the positive lead. Similarly, the current-collecting flux portion 12 of the unpainted portion of the negative electrode is joined (connected) to the negative lead, and is electrically connected to the negative terminal via the negative lead. Therefore, in each of the pair of unpainted portions 11, the current-collecting flux portion 12 is joined (connected) to the corresponding lead 17 of the pair.

[0021] In the example shown in Figures 1 and 2, a clip (backup lead) 18 is attached to the current-collecting flux portion 12 in each of the pair of unpainted portions 11. Each clip 18 is made of a conductive material. In each of the unpainted portions 11, the current-collecting flux portion 12 is joined (connected) to the corresponding lead of the pair of leads 17, with the clip 18 in between. In the internal cavity 10 of the outer container 5, the pair of unpainted portions 11, the pair of leads 17, and the clip 18 are electrically insulated from the outer container 5 and the outer part 3, including the lid member 6, by one or more insulating members (not shown).

[0022] In the example battery 1 shown in Figure 1, each of the pair of leads 17 is provided with a top plate portion 21 and a leg plate portion 22, with one leg plate portion 22 formed on each lead 17. In the internal cavity 10, each top plate portion 21 of the lead 17 is positioned between the lid member 6 and the electrode group 2 in the height direction of the battery 1. In each lead 17, the leg plate portion 22 is connected to the top plate portion 21. In the internal cavity 10, in each lead 17, the leg plate portion 22 extends along the height direction of the battery 1 from the connection point to the top plate portion 21 toward the side where the bottom wall 7 is located.

[0023] In battery 1, the leg plate portion 22 of the positive electrode lead is stacked on the current-collecting flux portion 12 of the unpainted positive electrode from one side in the thickness direction of the electrode group 2 (depth direction of battery 1), and is joined to the current-collecting flux portion 12 and the clip 18. Similarly, in battery 1, the leg plate portion 22 of the negative electrode lead is stacked on the current-collecting flux portion 12 of the unpainted negative electrode from one side in the thickness direction of the electrode group 2, and is joined to the current-collecting flux portion 12 and the clip 18. Therefore, in each of the pair of leads 17, the leg plate portion 22 becomes a joining plate portion to which a corresponding current-collecting flux portion 12 is joined. In each of the leads 17, the leg plate portion 22 that becomes the joining plate portion is stacked on the corresponding current-collecting flux portion 12 from one side in the thickness direction of the electrode group 2, and is joined (connected) to the corresponding current-collecting flux portion 12.

[0024] Figure 3 is a schematic diagram showing an example of the configuration of the connection portion (connection portion) of one current collection bundle portion 12 of the electrode group 2 to the lead 17, and its vicinity, in a battery 1 according to the first embodiment, as viewed from one side in the thickness direction of the electrode group 2. In Figure 3, the state is shown as viewed from one side in the depth direction (the stacking direction of the multiple current collection bundle portions 13) of the battery 1, and is shown as viewed from the side opposite to the side where the leads 17 (leg plate portions 22) in the thickness direction of the electrode group 2 are stacked.

[0025] Figure 4 is a schematic cross-sectional view showing a cross-section along the dashed line A1 in Figure 3. Figure 5 is a schematic cross-sectional view showing a cross-section along the dashed line A2 in Figure 3. In Figure 4, the connection portion of a current-collecting flux unit 12 to the lead 17, and the configuration of its vicinity, are shown in a cross-section perpendicular or approximately perpendicular to the width direction of the electrode group 2 (height direction of the battery 1). In Figure 5, the connection portion of a current-collecting flux unit 12 to the lead 17, and the configuration of its vicinity, are shown in a cross-section perpendicular or approximately perpendicular to the length direction of the electrode group 2 (protruding direction of the current-collecting flux unit 12 and lateral direction of the battery 1).

[0026] The following describes the configuration of the connection portion (connection part) of a current collection section 12 to the lead 17. In battery 1, the configuration of the connection portion of the current collection section 12 to the lead 17 in both the unpainted positive electrode portion and the unpainted negative electrode portion is the same as the configuration described below.

[0027] As shown in Figures 3 to 5, at the joint (connection) where the current-collecting flux portion 12, lead 17, and clip 18 are joined, and in its vicinity, the clip 18 sandwiches the current-collecting flux portion 12 from both sides in the thickness direction of the electrode group 2 (the stacking direction of the multiple current-collecting strip portions 13). The clip 18 is attached to the current-collecting flux portion 12 in a state close to the protruding end E1 of the current-collecting flux portion 12 from the side where the current-collecting flux portion 12 protrudes (the outside in the longitudinal direction of the electrode group 2). In a cross-section perpendicular or nearly perpendicular to the width direction of the electrode group 2, the clip 18 has a U-shape or a nearly U-shape (see Figures 2 and 4). The U-shape or nearly U-shape of the clip 18 opens toward the inside in the longitudinal direction of the electrode group 2, that is, toward the opposite side from the side where the current-collecting flux portion 12 protrudes (towards arrow L2 in Figures 3 and 4).

[0028] In the example shown in Figures 3 to 5, the leg plate portion 22 of the lead 17 is stacked on the current flux portion 12 and the clip 18 from one side in the thickness direction of the electrode group 2 (the side indicated by arrow C1 in Figures 4 and 5). The leg plate portion 22 of the lead 17 is then joined (connected) to the current flux portion 12 and the clip 18 while stacked on top of them. At the joining portion and its vicinity, the lead 17 abuts against the clip 18 from one side in the thickness direction of the electrode group 2. The leg plate portion 22 is joined to the current flux portion 12 with its width direction aligned with the length direction of the electrode group 2 (the protruding direction of the current flux portion 12) and its thickness direction aligned with the thickness direction of the electrode group 2 (the stacking direction of the multiple current collection strip portions 13).

[0029] Furthermore, a groove 23 is formed at the joint between the lead 17 and the current-collecting flux section 12. The groove 23 comprises a groove circumferential surface 25 and a groove bottom (groove bottom surface) 26. The groove 23 is recessed toward the lead 17 up to the groove bottom 26, and recesses toward the side where the lead 17 in the thickness direction of the electrode group 2 is located (arrow C1 side). The groove 23 opens toward the side opposite to where the lead 17 in the thickness direction of the electrode group 2 is located. The opening edge of the opening of the groove 23 is formed by the groove circumferential surface 25. A reference surface 27 is formed on the outer surface of the clip 18, facing away from the side where the lead 17 in the thickness direction of the electrode group 2 is stacked. In the example shown in Figures 3 to 5, the groove 23 opens on the reference surface 27 of the clip 18. Furthermore, the groove 23 is recessed toward the side where the lead 17 is located from the reference surface 27, and a step is formed between the reference surface 27 and the groove bottom 26 by the groove circumferential surface 25.

[0030] Furthermore, the leg plate portion (joining plate portion) 22 of the lead 17 has a pair of plate edges 31 and 32 that form both edges in the plate width direction. In the leg plate portion 22, the plate edge (first plate edge) 31 is the edge on one side in the plate width direction, and the plate edge (second plate edge) 32 is the edge on the opposite side from the plate edge 31 in the plate width direction. In the leg plate portion 22 joined to the current collection flux portion 12, the plate edge 31 is located further away from the protruding end E1 of the current collection flux portion 12 compared to the plate edge 32. That is, in and near the joining portion, the plate edge 31 is located on the opposite side (towards arrow L2 in Figures 3 and 4) from the side on which the current collection flux portion 12 protrudes, relative to the plate edge 32.

[0031] In a preferred example, such as the one shown in Figures 3 to 5, the entire groove 23, including the groove bottom 26, is located on the side of the plate edge 31 of the leg plate 22 where the current-collecting flux portion 12 protrudes (outside in the longitudinal direction of the electrode group 2). Therefore, in the joint, the groove 23 (groove circumferential surface portion 25 and groove bottom 26) does not protrude (does not protrude) on the side of the lead 17 opposite to the side where the current-collecting flux portion 12 protrudes in the longitudinal direction of the electrode group 2.

[0032] Furthermore, in a preferred example such as the one shown in Figures 3 to 5, the entire groove 23 at the joint is located on the opposite side (inside in the longitudinal direction of the electrode group 2) from the side on which the current-collecting flux portion 12 protrudes relative to the plate edge 32 of the leg plate portion 22. Therefore, at the joint, the groove 23 does not protrude (does not protrude) toward the side on which the current-collecting flux portion 12 protrudes relative to the lead 17 in the longitudinal direction of the electrode group 2. Thus, in a preferred example, the entire groove 23 at the joint is contained within the range between the plate edges 31 and 32 of the leg plate portion 22 in the longitudinal direction of the electrode group 2.

[0033] Furthermore, in this embodiment, a recessed structure portion 30 is formed in the joint portion, recessed from the groove bottom portion 26. The recessed structure portion 30 comprises one or more recesses 33 and is composed of one or more recesses 33. Each of the recesses 33 is further recessed from the groove bottom portion 26 of the groove portion 23 toward the side where the lead 17 in the thickness direction of the electrode group 2 is located. Here, in the joint portion, the amount of recession X1 from the reference surface 27 to the groove bottom portion 26 of the groove portion 23, and the amount of recession X2 from the reference surface 27 to the bottom of each recess 33 are defined, respectively. In this embodiment, because of the configuration described above, the amount of recession X2 of each recess 33 is larger than the amount of recession X1 from the groove bottom portion 26 of the groove portion 23.

[0034] In one example, each of the recesses 33 does not reach the lead 17, and the bottom of each recess 33 is located close to the reference plane 27 relative to the lead 17. In another example, each of the recesses 33 is recessed from the groove bottom 26 down to the lead 17. Each of the recesses 33 is formed in one of the following shapes, for example, a polygonal pyramidal shape, a frustum-shaped polygonal pyramidal shape, a conical shape, a frustum-shaped cone, or a similar shape.

[0035] In the example shown in Figures 3 to 5, the recessed structure 30 is composed of multiple (three) recesses 33. These multiple recesses 33 are arranged along the width direction of the electrode group 2, and the multiple recesses 33 form a single row of recesses 35. In the recessed structure 30 (row of recesses 35) in the example shown in Figures 3 to 5, the multiple recesses 33 are not offset from each other, or are only slightly offset, in the longitudinal direction of the electrode group 2. Therefore, the distance between the protruding end E1 of the current collection section 12 and the electrode group 2 along the longitudinal direction is the same or approximately the same for all of the multiple recesses 33 forming the row of recesses 35. In the example shown in Figures 3 to 5, only one row of recesses 35 is formed in the recessed structure 30. Therefore, the distance between the protruding end E1 of the current collection section 12 and the electrode group 2 along the longitudinal direction is the same or approximately the same for all of the multiple recesses 33 constituting the recessed structure 30.

[0036] In this embodiment, the groove bottom 26 of the groove 23 is adjacent to the recessed structure 30 from the side opposite to the side from which the current-collecting flux portion 12 protrudes in the longitudinal direction. Therefore, the groove 23 protrudes from the recessed structure 30 toward the side opposite to the side from which the current-collecting flux portion 12 protrudes (towards the inside in the longitudinal direction of the electrode group 2). In the example shown in Figures 3 to 5, the groove bottom 26 is adjacent to the row of recesses 35 from the side opposite to the side from which the current-collecting flux portion 12 protrudes, and is adjacent to each of the recesses 33 that make up the row of recesses 35 from the side opposite to the side from which the current-collecting flux portion 12 protrudes.

[0037] Therefore, in this embodiment, the groove bottom 26 extends in the region on the inner side of the length direction of the electrode group 2 (opposite the side from which the current-collecting flux portion 12 protrudes) from the end of the recessed structure 30 opposite to the side from which the current-collecting flux portion 12 protrudes. In the recessed structure 30, for example, the position through which the imaginary line α1 (see Figure 3) passes is the end opposite to the side from which the current-collecting flux portion 12 protrudes. Also, in a preferred example such as the example in Figures 3 to 5, as described above, the groove 23 does not protrude from the lead 17 toward the side opposite to the side from which the current-collecting flux portion 12 protrudes in the length direction of the electrode group 2. For this reason, in a preferred example, the groove bottom 26 extends between the plate edge 31 of the lead 17 and the end of the recessed structure 30 through which the imaginary line α1 passes.

[0038] Furthermore, in a preferred example such as the one shown in Figures 3 to 5, the groove portion 23 (groove bottom portion 26) does not protrude toward the side where the current-collecting flux portion 12 protrudes relative to the recessed structure portion 30. That is, the groove portion 23 does not protrude toward the outer side in the longitudinal direction of the electrode group 2 (the side where the current-collecting flux portion 12 protrudes) relative to the end of the recessed structure portion 30 on the side where the current-collecting flux portion 12 protrudes. In the recessed structure portion 30, for example, the position through which the imaginary line α2 (see Figure 3) passes is the end on the side where the current-collecting flux portion 12 protrudes. In the example shown in Figures 3 to 5, the groove portion 23 does not protrude toward the side where the current-collecting flux portion 12 protrudes relative to the recessed row 35, and does not protrude toward the side where the current-collecting flux portion 12 protrudes relative to each of the recesses 33 constituting the recessed row 35.

[0039] Furthermore, in a preferred example such as the one shown in Figures 3 to 5, the groove portion 23 (groove bottom portion 26) does not protrude in the width direction of the electrode group 2 relative to the recessed structure portion 30. For this reason, the groove portion 23 is not formed in the region outside the width direction of the electrode group 2 relative to the recessed structure portion 30. In the recessed structure portion 30, for example, the position through which the imaginary line γ1 (see Figure 3) passes becomes one end of the electrode group 2 in the width direction, and the position through which the imaginary line γ2 (see Figure 3) passes becomes the other end of the electrode group 2 in the width direction. In a preferred example, the groove portion 23 does not protrude outward in the width direction of the electrode group 2 with respect to each of the imaginary lines γ1 and γ2. In the example shown in Figures 3 to 5, the groove portion 23 does not protrude on either side in the width direction of the recess row 35. That is, the groove portion 23 does not protrude outward in the width direction of each of the recesses 33 located at both ends in the width direction of the electrode group 2 within the recess row 35.

[0040] As described above, in a preferred example such as the one shown in Figures 3 to 5, the groove bottom 26 of the groove 23 is adjacent to the recessed structure 30 from the side opposite to the side on which the current-collecting flux portion 12 protrudes in the longitudinal direction. In this configuration, the groove 23 (groove bottom 26) protrudes only from the recessed structure 30 on the side opposite to the side on which the current-collecting flux portion 12 protrudes. Furthermore, the groove 23 does not protrude from the recessed structure 30 on the side on which the current-collecting flux portion 12 protrudes, nor on either side in the width direction.

[0041] Furthermore, in the example shown in Figures 3 to 5, in the recess row 35, each of the multiple recesses 33 has a gap between adjacent recesses 33. In the joint portion, the groove bottom 26 of the groove 23 extends between adjacent recesses 33 in the width direction of the electrode group 2 in the recess row 35. For this reason, in the example shown in Figures 3 to 5, the multiple recesses 33 constituting the recess structure 30 include two or more recesses 33 that are spaced apart in the width direction of the electrode group 2. The groove bottom 26 of the groove 23 extends between two or more recesses 33 that are spaced apart in the width direction. Also, in the example shown in Figures 3 to 5, in the portion where the recess row 35 is formed, the groove bottom 26 and the recesses 33 are arranged alternately along the width direction of the electrode group 2 (the arrangement direction in the recess row 35).

[0042] In the manufacturing of the battery 1 with the configuration described above, after forming the electrode group 2, the current-collecting flux portion 12 is joined to the corresponding lead 17 of a pair of leads 17 at each of the pair of unpainted portions 11 of the electrode group 2 by ultrasonic welding or the like. At this time, at each of the unpainted portions 11, the leads 17 are stacked on the current-collecting flux portion 12 from one side in the thickness direction of the electrode group 2. Then, at each of the unpainted portions 11, the current-collecting flux portion 12 is joined to the lead 17 by joining the portions to be joined where the current-collecting flux portion 12 and the leads 17 are stacked. Then, each of the pair of unpainted portions 11 is electrically connected to the corresponding terminal 15 of a pair of leads 15 via the corresponding lead 17.

[0043] In one example, with each of the pair of leads 17 having a corresponding terminal 15 connected to it, each of the pair of unpainted portions 11 is joined to a corresponding terminal of the lead 17. In another example, each of the pair of unpainted portions 11 is joined to a corresponding terminal of the pair of leads 17, and then each of the leads 17 has a corresponding terminal 15 connected to it.

[0044] In the manufacturing of the battery 1 example shown in Figure 1, the electrode group 2 and the pair of leads 17 are housed in the internal cavity 10 of the outer casing 5, with each of the pair of unpainted portions 11 electrically connected to the corresponding terminal 15 of the pair of leads 17 via the corresponding terminal 17. Then, with the electrode group 2 and leads 17 housed in the internal cavity 10, a lid member 6 is attached to the peripheral wall 8 of the outer casing 5, and the opening of the internal cavity 10 is closed with the lid member 6. Finally, the battery 1 is manufactured by performing a predetermined process, including pouring electrolyte into the internal cavity 10. The current collection portion 12 is joined to the leads 17 using a joining device.

[0045] Figure 6 is a schematic diagram showing an example of the configuration of a bonding device 40 used in the manufacture of a battery 1 in the first embodiment. In this embodiment, for example, each of the current-collecting flux portions 12 of the electrode group 2 is bonded to the corresponding one of the leads 17 using the bonding device 40. As shown in Figure 6, the bonding device 40 includes a bonding jig 41, a stage 42 such as an anvil, a pressurizing unit 45, and an ultrasonic transducer 43. When bonding parts to be bonded using the bonding device 40, the parts to be bonded are sandwiched between the bonding jig 41 and the stage 42.

[0046] The pressurizing unit 45 applies pressure to the joining jig 41 while the portion to be joined is sandwiched between the joining jig 41 and the stage 42. As a result, the portion to be joined, sandwiched between the joining jig 41 and the stage 42, is pressed by the joining jig 41. In one example, the pressurizing unit 45 applies pressure to the stage 42 instead of the joining jig 41. In this case, the portion to be joined, sandwiched between the joining jig 41 and the stage 42, is pressed by the stage 42. In another example, the pressurizing unit 45 applies pressure to both the joining jig 41 and the stage 42. In this case, the portion to be joined, sandwiched between the joining jig 41 and the stage 42, is pressed by both the joining jig 41 and the stage 42.

[0047] The ultrasonic transducer 43 generates ultrasonic vibrations when an AC power such as high-frequency power is supplied. The ultrasonic transducer 43 then transmits the generated ultrasonic vibrations to the parts to be joined through the joining jig 41 while the parts to be joined are sandwiched between the joining jig 41 and the stage 42. Therefore, in the joining device 40, while the parts to be joined are sandwiched between the joining jig 41 and the stage 42, pressure is applied to at least one of the joining jig 41 and the stage 42, and ultrasonic vibrations are transmitted to the parts to be joined, thereby joining the parts by ultrasonic welding or the like.

[0048] The joining jig 41 comprises a jig body 46 and a joining tip portion 47. In the joining jig 41, the jig body 46 extends from the base end to the tip end, and the joining tip portion 47 is connected to the tip end of the jig body 46. In the example shown in Figure 6, the joining tip portion 47 is bent relative to the jig body 46. However, in one example, the joining tip portion 47 may not be bent relative to the jig body 46, but may extend straight or nearly straight relative to the jig body 46.

[0049] In joining the parts to be joined, the joining tip portion 47 is brought into contact with the parts to be joined, and the parts to be joined are sandwiched between the joining tip portion 47 and the stage 42. In a configuration in which pressure is applied to the joining jig 41 from the pressurizing unit 45, the pressure applied from the pressurizing unit 45 causes the joining tip portion 47 to press against the parts to be joined. Furthermore, vibrations generated by the ultrasonic transducer 43 are transmitted to the parts to be joined by sequentially passing through the jig body 46 and the joining tip portion 47.

[0050] Figure 7 is a schematic perspective view showing an example of the configuration of the joining tip portion 47 of the joining jig 41 according to the first embodiment. As shown in Figure 7, the joining tip portion 47 comprises a base portion 51 and a projection base portion 52 that protrudes from the base portion 51. The joining tip portion 47 of the joining jig 41 has a defined projection direction of the projection base portion 52 (indicated by arrow P). In the example in Figure 7, a base surface 55 is formed on the base portion 51, and the projection base portion 52 protrudes from the base surface 55 in the projection direction. The joining tip portion 47 also has a defined width direction of the projection base portion 52 (indicated by arrow Q) that intersects (orthogonal or nearly orthogonal to) the projection direction of the projection base portion 52, and a defined depth direction of the projection base portion 52 (indicated by arrows D1 and D2) that intersects (orthogonal or nearly orthogonal to) both the projection direction and the width direction.

[0051] The projection base portion 52 comprises a base portion (base surface) 56 and a pair of base side portions (base sides) 57, 58. The base portion 56 faces the projection direction, and in the projection base portion 52, the projection end (projection end surface) of the projection that protrudes from the base surface 55 of the base portion 51 is formed by the base portion 56. Each of the base side portions 57, 58 extends from the base portion 51 to the base portion 56 in the projection direction of the projection base portion 52 and forms a part of the outer circumferential surface of the projection base portion 52. Each of the base side portions 57, 58 extends from the root of the projection of the projection base portion 52 to the projection end. The root of the projection of the projection base portion 52 is defined by the base surface 55 of the base portion 51, and the outer circumferential surface of the projection base portion 52 extends from the base portion 51 to the base portion 56 along the projection direction of the projection base portion 52.

[0052] The base side portion (first base side portion) 57 faces one side of the protruding base portion 52 in the depth direction (arrow D1 side), and the end of the protruding base portion 52 in the depth direction is formed by the base side portion 57. The base side portion (second base side portion) 58 faces the opposite side of the protruding base portion 52 in the depth direction (arrow D2 side), and the end of the protruding base portion 52 opposite to the base side portion 57 in the depth direction is formed by the base side portion 58.

[0053] In the example shown in Figure 7, the base surface 55 of the base 51 is adjacent to the protruding base 52 from the side facing the depth-direction side portion 58 of the protruding base 52. The end of the side portion 58 opposite to the protruding direction is connected to the base surface 55 of the base 51, and the side portion 58 extends from the base surface 55 toward the protruding direction. In the example shown in Figure 7, the base surface 55 is not formed in the region on the side facing the depth-direction side portion 57 relative to the protruding base 52. Furthermore, the base surface 55 is not formed in the region on the width side of the protruding base 52.

[0054] In this embodiment, a convex structure 50 is formed on the joint tip portion 47, protruding from the protruding base portion 52. The convex structure 50 comprises one or more protrusions 53 and is composed of one or more protrusions 53. Each of the protrusions 53 further protrudes from the base portion 56 toward the protruding direction of the protruding base portion 52. Therefore, each of the protrusions 53 further protrudes from the protruding end of the protruding base portion 52.

[0055] Here, the projection length H1 along the projection direction from the base surface 55 of the base portion 51 to the projection end of one or more projections 53 of the convex structure portion 50, and the projection length H2 along the projection direction from the base portion 56 of the projection base portion 52 to the projection end of one or more projections 53 are defined (see Figures 8 and 9 described later). In this embodiment, because of the configuration described above, the projection length H1 is larger than the projection length H2. Each of the projections 53 is formed in one of the following shapes, for example, a polygonal pyramidal shape, a frustoconical shape, a cone shape, a frustoconical shape, or a shape similar thereto.

[0056] Each of the one or more projections 53 is provided with a pair of projection lateral portions (projection sides) 61, 62. In each of the one or more projections 53, each of the projection lateral portions 61, 62 extends from the base portion 56 of the projection base portion 52 toward the projection direction and extends to the projection end of the projection 53. In addition, in each of the one or more projections 53, each of the projection lateral portions 61, 62 forms a part of the outer circumferential surface of the projection 53. In each of the projections 53, the outer circumferential surface extends from the base portion 56 toward the projection end of the projection 53 along the projection direction of the projection base portion 52.

[0057] In each of the projections 53, the projection lateral portion (first projection lateral portion) 61 faces the side (arrow D1 side) facing the base lateral portion (first base lateral portion) 57 in the depth direction, and the projection lateral portion (second projection lateral portion) 62 faces the side (arrow D2 side) facing the base lateral portion (second base lateral portion) 58 in the depth direction. In addition, in each of the projections 53, one end in the depth direction is formed by the projection lateral portion 61, and the end opposite to the projection lateral portion 61 in the depth direction is formed by the projection lateral portion 62.

[0058] In the example shown in Figure 7, the convex structure 50 is composed of multiple (three) protrusions 53. The multiple protrusions 53 are arranged along the width direction of the protruding base 52, and the multiple protrusions 53 form a single row of protrusions 63. In the convex structure 50 (row of protrusions 63) of the example shown in Figure 7, the multiple protrusions 53 are not offset from each other, or are only slightly offset, in the depth direction of the protruding base 52. Therefore, the distance between the protruding base 52 from the base side portion 57 along the depth direction is the same or approximately the same for all of the multiple protrusions 53 forming the row of protrusions 63. Similarly, the distance between the protruding base 52 from the base side portion 58 along the depth direction is the same or approximately the same for all of the multiple protrusions 53 forming the row of protrusions 63.

[0059] Furthermore, in the example shown in Figure 7, only one row of protrusions 63 is formed in the convex structure 50. Therefore, the distance between the protruding base portion 52 from the base side portion 57 along the depth direction is the same or approximately the same for all of the multiple protrusions 53 constituting the convex structure 50. Similarly, the distance between the protruding base portion 52 from the base side portion 58 along the depth direction is the same or approximately the same for all of the multiple protrusions 53 constituting the convex structure 50.

[0060] In this embodiment, the base portion 56 of the protruding base portion 52 is adjacent to the convex structure portion 50 from the side facing the base side portion (first base side portion) 57 in the depth direction of the protruding base portion 52. Therefore, the base portion 56 protrudes from the convex structure portion 50 toward the side facing the base side portion 57. In the example shown in Figure 7, the base portion 56 is adjacent to the row of protrusions 63 from the side facing the base side portion 57, and is adjacent to each of the protrusions 53 that make up the row of protrusions 63 from the side facing the base side portion 57. Thus, in this embodiment, the base portion 56 extends from the end of the convex structure portion 50 toward the side facing the base side portion 57 to the region of the protruding base portion 52 toward the base side portion 57 in the depth direction. In the convex structure portion 50, for example, the position through which the imaginary line β1 (see Figure 7) passes is the end facing the base side portion 57.

[0061] In a preferred example, such as the one shown in Figure 7, the base portion 56 does not protrude toward the side of the base portion (second base portion) 58 relative to the convex structure portion 50. That is, the base portion 56 does not protrude toward the side of the base portion 58 in the depth direction of the protruding base portion 52 relative to the end of the convex structure portion 50 toward the side of the base portion 58. In the convex structure portion 50, for example, the position through which the imaginary line β2 (see Figure 7) passes is the end of the side of the base portion 58. In the example shown in Figure 7, the base portion 56 does not protrude toward the side of the base portion 58 relative to the row of protrusions 63, and does not protrude toward each of the protrusions 53 constituting the row of protrusions 63 relative to the side of the base portion 58. Then, each of the side portions 62 of the protrusions 53 is connected to the base portion 58 of the protruding base portion 52 without the base portion 56 being in between.

[0062] Furthermore, in a preferred example such as the one shown in Figure 7, the base portion 56 does not protrude in the width direction of the protruding base portion 52 relative to the convex structure portion 50. For this reason, the base portion 56 is not formed in the area outside the width direction of the protruding base portion 52 relative to the convex structure portion 50. In the convex structure portion 50, for example, the position through which the imaginary line ε1 (see Figure 7) passes becomes one end of the protruding base portion 52 in the width direction, and the position through which the imaginary line ε2 (see Figure 7) passes becomes the other end of the protruding base portion 52 in the width direction. In a preferred example, the base portion 56 does not protrude outward in the width direction of the protruding base portion 52 relative to each of the imaginary lines ε1 and ε2. In the example shown in Figure 7, the base portion 56 does not protrude on either side in the width direction relative to the row of protrusions 63. That is, the base portion 56 does not protrude outward in the width direction relative to each of the protrusions 53 located at both ends in the width direction of the protruding base portion 52 among the protrusions 53 that constitute the row of protrusions 63.

[0063] As mentioned above, in a preferred example such as the one shown in Figure 7, the base portion 56 is adjacent to the convex structure portion 50 from the side of the protruding base portion 52 facing the side of the base portion (first base portion) 57 in the depth direction, and the base portion 56 protrudes from the convex structure portion 50 only on the side of the base portion 57 facing. The base portion 56 does not protrude from the convex structure portion 50 on the side of the base portion (second base portion) 58 facing, nor on either side of the protruding base portion 52 in the width direction.

[0064] Furthermore, in the example shown in Figure 7, in the row of protrusions 63, each of the multiple protrusions 53 has a gap between adjacent protrusions 53. In the joint tip portion 47, a base portion 56 extends between adjacent protrusions 53 in the width direction of the protruding base portion 52 in the row of protrusions 63. Therefore, in the example shown in Figure 7, the multiple protrusions 53 constituting the convex structure portion 50 include two or more protrusions 53 that are spaced apart in the width direction of the protruding base portion 52. The base portion 56 extends between two or more protrusions 53 that are spaced apart in the width direction. Also, in the example shown in Figure 7, in the portion where the row of protrusions 63 is formed, the base portion 56 and the protrusions 53 are arranged alternately along the width direction of the protruding base portion 52 (the arrangement direction in the row of protrusions 63).

[0065] Furthermore, in the example shown in Figure 7, in the jointed tip portion 47, the base surface 55 of the base portion 51 is located on the side of the protruding base portion 52 in the depth direction that faces the convex structure portion 50. Therefore, the base surface 55 is located on the side of the base portion 58 that faces any of the protrusions 53 that constitute the convex structure portion 50. Also, in the example shown in Figure 7, the base surface 55 is not formed in the region on the side of the base portion 57 in the depth direction that faces the convex structure portion 50. And the base surface 55 is not formed in the region on the outer side in the width direction relative to the convex structure portion 50.

[0066] In joining the current-collecting flux section 12 to the lead 17, the joining target area, where the current-collecting flux section 12 and the lead 17 are stacked, is sandwiched between the joining tip section 47 and the stage 42 of the joining jig 41. At this time, as shown in Figure 6, the joining tip section 47 contacts the joining target area from the side opposite to the side where the lead 17 in the thickness direction of the electrode group 2 is stacked. The stage 42 then contacts the joining target area from the side where the lead 17 in the thickness direction of the electrode group 2 is stacked.

[0067] Then, with the portion to be joined sandwiched between the joining jig 41 and the stage 42, pressure is applied to at least one of the joining jig 41 and the stage 42 by the pressurizing unit 45, pressing the portion to be joined by at least one of the joining jig 41 and the stage 42. Also, with the portion to be joined sandwiched between the joining jig 41 and the stage 42, ultrasonic vibrations are transmitted to the portion to be joined through the joining jig 41. As a result, the portion to be joined is joined, and a joint portion is formed in which the current collection flux portion 12 and the lead 17 are joined.

[0068] Figure 8 is a schematic diagram showing an example of a state in the first embodiment where one current-collecting flux portion 12 of the electrode group 2 is joined to a lead 17, in a cross-section perpendicular or approximately perpendicular to the width direction of the electrode group 2. Figure 9 is a schematic diagram showing the state in Figure 8 in a cross-section perpendicular or approximately perpendicular to the length direction of the electrode group 2 (the protruding direction of the current-collecting flux portion 12). In Figure 8, a portion of the joining tip portion 47 is shown in a cross-section perpendicular or approximately perpendicular to the width direction of the protruding base portion 52, and the remaining portion is shown when viewed from one side in the width direction of the protruding base portion 52. In Figure 9, a portion of the joining tip portion 47 is shown in a cross-section perpendicular or approximately perpendicular to the depth direction of the protruding base portion 52, and the remaining portion is shown when viewed from one side in the depth direction of the protruding base portion 52.

[0069] The following describes the connection of a current-collecting flux section 12 to the lead 17. In the manufacture of the battery 1, the connection of the current-collecting flux section 12 to the lead 17 is performed in the same manner as described below for both the unpainted positive electrode portion and the unpainted negative electrode portion.

[0070] As shown in Figures 8 and 9, when joining the current flux collection portion 12 to the lead 17, the joining tip portion 47 is brought into contact with the joining target portion with the protruding base portion 52 and one or more protrusions 53 of the convex structure portion 50 protruding toward the joining target portion. Therefore, when joining the joining target portion is being performed, the protruding direction of the protruding base portion 52 is along the thickness direction of the electrode group 2, and the protruding base portion 52 protrudes from the base portion 51 toward the side where the lead 17 is located (arrow C1 side). Furthermore, when joining the current flux collection portion 12 to the lead 17, the joining tip portion 47 is brought into contact with the joining target portion with the width direction of the protruding base portion 52 (direction indicated by arrow Q) aligned with the width direction of the electrode group (direction indicated by arrow W), and the depth direction of the protruding base portion 52 (directions indicated by arrows D1 and D2) aligned with the length direction of the electrode group (directions indicated by arrows L1 and L2). Furthermore, the joining tip portion 47 contacts the portion to be joined with the side portion (first side portion) 57 of the protruding base portion 52 facing the opposite side (arrow L2 side) from the side from which the current flux portion 12 protrudes.

[0071] In joining the current-collecting flux section 12 to the lead 17, pressure is applied to at least one of the joining jig 41 and the stage 42, causing the base portion 56 of the joining tip portion 47 and one or more protrusions 53 of the convex structure portion 50 to come into contact with the portion to be joined. With the base portion 56 of the joining tip portion 47 and one or more protrusions 53 in contact with the portion to be joined, ultrasonic vibrations are transmitted to the portion to be joined through the joining tip portion 47, thereby joining the portion to be joined by ultrasonic welding. As described above, when the current-collecting flux section 12 is joined to the lead 17 in this manner, the groove bottom portion 26 of the groove portion 23 is formed in the portion where the base portion 56 made contact, and recesses 33 are formed in each of the portions where one or more protrusions 53 of the convex structure portion 50 made contact. Then, one or more recesses 33 form a recessed structure portion 30.

[0072] In this embodiment, in the joining jig 41 used for joining, the base portion 56 is adjacent to the convex structure portion 50 from the side facing the depth-direction side portion 57 of the protruding base portion 52. Therefore, at the joining portion of the current-collecting flux portion 12 and the lead 17, the groove bottom portion 26 of the groove portion 23 is adjacent to the concave structure portion 30 from the side opposite to the side from which the current-collecting flux portion 12 protrudes in the longitudinal direction of the electrode group 2.

[0073] Furthermore, when joining the parts to be joined, the base portion 56 and one or more protrusions 53 of the convex structure portion 50 are brought into contact with the parts to be joined, but the base portion 51, including the base surface 55, does not come into contact with the parts to be joined. For this reason, the amount of recess X2 from each reference surface 27 of the recess 33 is smaller than the protrusion length H1 along the protrusion direction from the base surface 55 of the base portion 51 to the protruding end of one or more protrusions 53 of the convex structure portion 50. And the amount of recess X2 from each reference surface 27 of the recess 33 is larger than the protrusion length H2 along the protrusion direction from the base portion 56 of the protruding base portion 52 to the protruding end of one or more protrusions 53.

[0074] Furthermore, in a preferred example of this embodiment, the base portion 56 and one or more protrusions 53 are brought into contact with the joining portion such that the base portion 56 does not protrude relative to the lead 17 on either the side where the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes, or on the side opposite to the side where the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes. For this reason, in a preferred example, similar to the example in Figures 3 to 5, the groove portion 23 does not protrude relative to the lead 17 on either the side where the current-collecting flux portion 12 protrudes, or on the side opposite to the side where the current-collecting flux portion 12 protrudes.

[0075] Furthermore, in a preferred example of this embodiment, in the joining jig 41 used for joining the parts to be joined, the base portion 56 does not protrude toward the side of the base lateral portion (second base lateral portion) 58 relative to the convex structure portion 50, similar to the joining jig 41 in the example shown in Figure 7. For this reason, in a preferred example, similar to the examples shown in Figures 3 to 5, the groove portion 23 does not protrude toward the concave structure portion 30 toward the side of the current collection flux portion 12 that protrudes in the longitudinal direction of the electrode group 2 at the joining portion of the current collection flux portion 12 and the lead 17.

[0076] Furthermore, in a preferred example of this embodiment, in the joining jig 41 used for joining the parts to be joined, the base portion 56 does not protrude on either side in the width direction of the protruding base portion 52 relative to the convex structure portion 50, similar to the joining jig 41 in the example shown in Figure 7. Therefore, in a preferred example, similar to the examples shown in Figures 3 to 5, the groove portion 23 does not protrude on either side in the width direction of the concave structure portion 30 relative to the electrode group 2 at the joining portion of the current collection flux portion 12 and the lead 17.

[0077] Furthermore, in one example of this embodiment, in the joining jig 41 used for joining the parts to be joined, a base portion 56 extends between two or more projections 53 that are spaced apart in the width direction of the protruding base portion 52. For this reason, in this example, similar to the examples in Figures 3 to 5, the groove bottom portion 26 of the groove portion 23 extends between two or more recesses 33 that are spaced apart in the width direction of the electrode group 2 at the joining portion of the current collection flux portion 12 and the lead 17.

[0078] As described above, in this embodiment, the base portion 56 forms the protruding end of the protruding base portion 52 that protrudes from the base portion 51, and each of the one or more protrusions 53 of the convex structure portion 50 further protrudes from the base portion 56 toward the protruding direction of the protruding base portion 52. The joining jig 41 is used to join the parts to be joined. When joining the parts to be joined, the base portion 56 and one or more protrusions 53 of the joining jig 41 are brought into contact with the parts to be joined from the side opposite to the side on which the thickness-direction leads 17 of the electrode group 2 are stacked. By joining the current-collecting flux portion 12 to the leads 17 with the base portion 56 in contact with the parts to be joined in addition to one or more protrusions 53, the joining strength at the joining portion is improved.

[0079] Furthermore, in this embodiment, the base portion 56 is used for joining the joining jig 41 adjacent to the convex structure portion 50 from the side facing the depth-direction side portion (first base portion) 57 of the protruding base portion 52. When joining the portions to be joined, the base portion 56 and one or more protrusions 53 of the convex structure portion 50 are brought into contact with the portions to be joined, with the base portion 57 facing the side opposite to the side from which the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes. As a result, in the portion adjacent to the portion in contact with the convex structure portion 50 on the side opposite to the side from which the current-collecting flux portion 12 protrudes, the portions to be joined are pressed by the base portion 56 toward the side from which the lead 17 in the thickness direction of the electrode group 2 is located. As a result, at the joint portions of the lead 17 and the current-collecting flux portion 12, etc., the upward curvature of the current-collecting flux portion 12 and the clip 18, etc., toward the side opposite to the side where the lead is located in the thickness direction is appropriately suppressed in the portion adjacent to the side opposite to the side where the current-collecting flux portion 12 protrudes relative to the recessed structure portion 30. Therefore, the joint between the lead 17 and the current-collecting flux portion 12, etc., is appropriately ensured in the portion adjacent to the side opposite to the side where the current-collecting flux portion 12 protrudes relative to the recessed structure portion 30.

[0080] Here, by ensuring a proper connection at the portion adjacent to the recessed structure 30 on the opposite side from where the current-collecting flux portion 12 protrudes, the current-collecting flux portion 12 is properly connected to the corresponding terminal 15 via the connected lead 17 or the like. This ensures that the electrical connection of each current-collecting flux portion 12 to the corresponding terminal 15 is properly secured.

[0081] Furthermore, in a preferred example of this embodiment, the base portion 56 and one or more protrusions 53 of the convex structure portion 50 are brought into contact with the joining target portion, such that the base portion 56 does not protrude relative to the lead 17 on the side where the current-collecting flux portion 12 protrudes in the longitudinal direction of the electrode group 2. As a result, during joining, the portion of the base portion 56 that contacts the joining target portion is separated to a certain extent inward in the longitudinal direction of the electrode group 2 from the protruding end E1 of the current-collecting flux portion 12. As described above, by the base portion 56 contacting the joining target portion, excessive expansion of the joining portion toward the side where the current-collecting flux portion 12 protrudes due to joining is effectively prevented. In other words, improper deformation of the joining portion including the current-collecting flux portion 12 due to joining is appropriately suppressed. Therefore, in joining the current-collecting flux portion 12 of the electrode group 2 to the lead 17, joining is ensured at a portion adjacent to the concave structure portion 30 on the opposite side from where the current-collecting flux portion 12 protrudes, while improper deformation of the joining portion due to joining is suppressed.

[0082] For example, by suppressing excessive expansion of the joint portion toward the side where the current-collecting flux portion 12 protrudes, the joint portion of the current-collecting flux portion 12 and the lead 17 becomes less likely to interfere with the outer container 5 when housing the electrode group 2 and the lead 17 into the inner cavity 10 of the outer container 5. As a result, when housing the electrode group 2 and the lead 17 into the inner cavity 10 of the outer container 5, the assembly with the electrode group 2 and the lead 17 assembled becomes easier to insert into the inner cavity 10. Therefore, the work efficiency of housing the electrode group 2 and the lead 17 into the inner cavity 10 during the manufacturing of the battery 1 is improved.

[0083] Furthermore, in a preferred example of this embodiment, the base portion 56 does not protrude relative to the lead 17 on the side opposite to the side from which the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes, and one or more protrusions 53 of the base portion 56 and the convex structure portion 50 are brought into contact with the portion to be joined. This further effectively suppresses improper deformation of the joined portion caused by joining. In addition, by joining in this manner, the joint strength at the portion adjacent to the concave structure portion 30 on the side opposite to the side from which the current-collecting flux portion 12 protrudes is further improved.

[0084] Furthermore, in a preferred example of this embodiment, a joining jig 41 or the like is used for joining, such that the base portion 56 does not protrude relative to the convex structure portion 50 on the side facing the base side portion (second base side portion) 58, and at the joining portion, the groove portion 23 is formed such that the groove portion 23 does not protrude relative to the concave structure portion 30 on the side where the current flux portion 12 protrudes. This further effectively prevents the joining portion from expanding excessively on the side where the current flux portion 12 protrudes due to joining. Therefore, inappropriate deformation of the joining portion due to joining is further appropriately suppressed.

[0085] Furthermore, in a preferred example of this embodiment, a joining jig 41 or the like is used for joining, in which the base portion 56 does not protrude beyond the convex structure portion 50 in the width direction of the protruding base portion 52, and at the joining portion, the groove portion 23 is formed in such a way that the groove portion 23 does not protrude beyond the concave structure portion 30 in the width direction of the electrode group 2. This further appropriately suppresses inappropriate deformation of the joining portion caused by joining. In addition, because the base portion 56 does not protrude beyond the convex structure portion 50 in the width direction of the protruding base portion 52, it becomes easier to bring the portion of the base portion 56 adjacent to the convex structure portion 50 from the side facing the base side portion 57 into contact with the portion to be joined. As a result, at the joining portion of the lead 17 and the current collection flux portion 12, the upward curvature of the current collection flux portion 12 and the clip 18 is further appropriately suppressed at the portion adjacent to the side opposite to the side on which the current collection flux portion 12 protrudes relative to the concave structure portion 30.

[0086] Furthermore, in one example of this embodiment, a joining jig 41 is used for joining in which a base portion 56 extends between two or more projections 53 that are spaced apart in the width direction of a protruding base portion 52. As a result, at the joining portion, the groove bottom portion 26 of the groove portion 23 extends between two or more recesses 33 that are spaced apart in the width direction of the electrode group 2. By performing the joining with the base portion 56 in contact with the parts to be joined between the spaced-apart recesses 33, the joining strength at the joining portion is further improved.

[0087] (modified version) Figure 10 is a schematic diagram showing an example of the configuration of the connection portion (connection portion) of one current-collecting portion 12 of the electrode group 2 to the lead 17, and its vicinity, in a battery 1 according to the first modified example. Figure 11 is a schematic diagram showing an example of the configuration of the connection portion (connection portion) of one current-collecting portion 12 of the electrode group 2 to the lead 17, and its vicinity, in a battery 1 according to the second modified example. In both the first modified example shown in Figure 10 and the second modified example shown in Figure 11, one or more recesses 33 of the groove portion 23 and recessed structure portion 30 are formed at the connection portion between the current-collecting portion 12 and the lead 17. The groove bottom portion 26 of the groove portion 23 is adjacent to the recessed structure portion 30 from the side opposite to the side on which the current-collecting portion 12 of the electrode group 2 protrudes in the longitudinal direction. Here, Figures 10 and 11 show the state of the electrode group 2 as viewed from one side in the thickness direction (the depth direction of the battery 1 and the stacking direction of the multiple current collector bands 13), and the state as viewed from the opposite side from the side on which the leads 17 (leg plate portions 22) in the thickness direction of the electrode group 2 are stacked.

[0088] In the first and second modified examples, as in the example in Figure 10 and the example in Figure 11, the groove 23 does not protrude from the lead 17 on the side where the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes, nor on the side opposite to the side where the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes. Also, in the example in Figure 10 and the example in Figure 11, as in the first embodiment, the recessed structure 30 is composed of a plurality of recesses 33, and in the recessed structure 30, a row of recesses 35 is formed in which the plurality of recesses 33 are arranged along the width direction of the electrode group 2. In the recessed structure 30 (row of recesses 35), the plurality of recesses 33 are not offset from each other, or are hardly offset, in the longitudinal direction of the electrode group 2.

[0089] In the first and second modified examples, as in the example in Figure 10 and the example in Figure 11, the groove portion 23 (groove bottom portion 26) does not protrude toward any of the recesses 33 forming the concave structure portion 30 (row of recesses 35) toward the side where the current flux portion 12 protrudes (outside in the longitudinal direction of the electrode group 2), and does not protrude toward the side where the current flux portion 12 protrudes toward the concave structure portion 30. In another preferred example, the groove portion 23 (groove bottom portion 26) does not protrude toward the concave structure portion 30 toward either side in the width direction of the electrode group 2.

[0090] Therefore, in the first and second modified examples, in a preferred configuration, the groove bottom 26 of the groove 23 is adjacent to the recessed structure 30 from the side opposite to the side from which the current-collecting flux portion 12 protrudes in the longitudinal direction, and the groove 23 (groove bottom 26) protrudes only from the recessed structure 30 on the side opposite to the side from which the current-collecting flux portion 12 protrudes. Furthermore, the groove 23 does not protrude from the recessed structure 30 on the side from which the current-collecting flux portion 12 protrudes, nor on either side in the width direction.

[0091] As shown in Figure 10, etc., in the first modified example, the recess row 35 consists of only two recesses 33, and the recessed structure 30 consists of only two recesses 33. However, even in the first modified example, the groove bottom 26 of the groove 23 extends between adjacent recesses 33 in the width direction of the electrode group 2 in the recess row 35. Therefore, the groove bottom 26 of the groove 23 extends between two recesses 33 that are separated in the width direction. Also, in the first modified example, the groove bottom 26 is adjacent to the recess row 35 from the side opposite to the side on which the current-collecting flux portion 12 protrudes.

[0092] As shown in Figure 11, etc., in the second modified example, in the recess row 35, the multiple recesses 33 are arranged continuously in the width direction of the electrode group 2. Therefore, in the recess row 35, no groove bottom 26 is formed between adjacent recesses 33 in the width direction of the electrode group 2. However, in this modified example as well, similar to the first embodiment and the first modified example, the groove bottom 26 is adjacent from the side opposite to the side from which the current-collecting flux portion 12 protrudes relative to the recess row 35.

[0093] In the first and second modified examples, the base portion 56 forms the protruding end of the protruding base portion 52 that protrudes from the base portion 51, and each of the one or more protrusions 53 of the convex structure portion 50 further protrudes from the base portion 56 toward the protruding direction of the protruding base portion 52. The joining jig 41 used for joining is used for joining the current flux portion 12 to the lead 17. In the joining jig 41 used for joining, the base portion 56 is adjacent to the convex structure portion 50 (row of protrusions 63) from the side facing the depth-direction side portion (first side portion) 57 of the protruding base portion 52. The joining is then performed in the same manner as in the first embodiment, and at the joining portion of the lead 17 and the current flux portion 12, the groove bottom portion 26 of the groove portion 23 is formed in the portion where the base portion 56 is in contact, and recesses 33 are formed in each of the portions where one or more protrusions 53 of the convex structure portion 50 are in contact.

[0094] In the first and second modified examples, in a preferred example, during joining, the base portion 56 and one or more protrusions 53 are brought into contact with the joining target portion, such that the base portion 56 does not protrude from the lead 17 on the side where the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes, and on the side opposite to where the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes. In the joining jig 41 used in the example in Figure 10 and the example in Figure 11, similar to the first embodiment, the convex structure portion 50 is composed of a plurality of protrusions 53, and the convex structure portion 50 forms a row of protrusions 63 in which the plurality of protrusions 53 are arranged along the width direction of the electrode group 2. In the convex structure portion 50 (row of protrusions 63), the plurality of protrusions 53 are not offset from each other, or are hardly offset, in the depth direction of the protruding base portion 52.

[0095] In the joining jig 41 of the first and second modified examples, in a preferred example, the base portion 56 does not protrude toward any of the protrusions 53 forming the convex structure portion 50 (row of protrusions 63) toward the side facing the base lateral portion (second base lateral portion) 58, and does not protrude toward the convex structure portion 50 toward the side facing the base lateral portion 58. In another preferred example, the base portion 56 does not protrude toward the convex structure portion 50 toward either side in the width direction of the protruding base portion 52.

[0096] Therefore, in the first and second modified examples, in a preferred configuration, the base portion 56 is adjacent to the convex structure portion 50 from the side of the base lateral portion (first base lateral portion) 57 in the depth direction of the protruding base portion 52 that faces the base portion 56. The base portion 56 does not protrude from the convex structure portion 50 to the side of the base lateral portion 57 that faces the base portion 58, nor to either side of the protruding base portion 52 in the width direction.

[0097] In one modified example, the recessed structure 30 is formed from only one recess 33 at the joint between the current flux collection portion 12 and the lead 17. In this modified example as well, the groove bottom 26 of the groove portion 23 is adjacent to the recessed structure 30 from the side opposite to the side from which the current flux collection portion 12 protrudes in the longitudinal direction of the electrode group 2. In this modified example, the groove bottom 26 is adjacent to the one recess 33 constituting the recessed structure 30 from the side opposite to the side from which the current flux collection portion 12 protrudes.

[0098] In this modified example, in a preferred example, the groove 23 does not protrude from the lead 17 on the side where the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes, nor on the side opposite to the side where the current-collecting flux portion 12 in the longitudinal direction of the electrode group 2 protrudes. Also in this modified example, in a preferred example, the groove 23 (groove bottom 26) does not protrude from the recessed structure 30 on the side where the current-collecting flux portion 12 protrudes (outside in the longitudinal direction of the electrode group 2). Therefore, in a preferred example, the groove 23 does not protrude from the one recess 33 forming the recessed structure 30 on the side where the current-collecting flux portion 12 protrudes. Also in a preferred example, the groove 23 does not protrude from the recessed structure 30 (one recess 33) on either side in the width direction of the electrode group 2.

[0099] In this modified example, the joining of the current-collecting flux section 12 to the lead 17 is performed in the same manner as in the previously described embodiments, except that the convex structure 50 is composed of a single projection 53, and a joining jig 41 is used in which only one projection 53 protrudes from the base portion 56. At the joining portion of the lead 17 and the current-collecting flux section 12, the groove bottom 26 of the groove portion 23 is formed in the portion that the base portion 56 contacts, and the recess 33 is formed in the portion that the projection 53 contacts. In this modified example as well, in the joining jig 41 used for joining, the base portion 56 is adjacent to the convex structure 50 (single projection 53) from the side facing the depth-direction side portion (first side portion) 57 of the protruding base portion 52.

[0100] In this modified example, in a preferred example, during joining, the base portion 56 and the projection 53 of the convex structure portion 50 are brought into contact with the joining target portion, such that the base portion 56 does not protrude relative to the lead 17 on the side where the longitudinal current-collecting flux portion 12 of the electrode group 2 protrudes, and on the side opposite to where the longitudinal current-collecting flux portion 12 of the electrode group 2 protrudes. In addition, in a preferred example of the joining jig 41 in this modified example, the base portion 56 does not protrude relative to the convex structure portion 50 on the side where the base side portion (first base side portion) 57 faces. Therefore, in the joining jig 41 of the preferred example, the base portion 56 does not protrude relative to the one projection 53 forming the convex structure portion 50 on the side where the base side portion 57 faces. In addition, in a preferred example, the base portion 56 does not protrude on either side in the width direction of the protruding base portion 52 relative to the convex structure portion 50 (one projection 53).

[0101] Figure 12 is a schematic diagram showing an example of the configuration of the connection portion (connection portion) of one current-collecting bundle portion 12 of the electrode group 2 to the lead 17, and its vicinity, in a battery 1 according to the third modified example, as viewed from one side in the thickness direction of the electrode group 2. In Figure 12, the state is shown as viewed from one side in the depth direction (the stacking direction of the multiple current-collecting bundle portions 13) of the battery 1, and as viewed from the side opposite to the side where the leads 17 (leg plate portions 22) in the thickness direction of the electrode group 2 are stacked. Figure 13 is a schematic cross-sectional view showing a cross section along the dashed line A3 in Figure 12. In Figure 13, the configuration of the connection portion of one current-collecting bundle portion 12 to the lead 17, and its vicinity, is shown in a cross section that is perpendicular or approximately perpendicular to the width direction of the electrode group 2 (height direction of the battery 1).

[0102] In the third modified example shown in Figures 12 and 13, one or more recesses 33 of the groove 23 and recessed structure 30 are formed at the joint between the current-collecting flux portion 12 and the lead 17. The groove bottom 26 of the groove 23 is adjacent to the recessed structure 30 from the side opposite to the side from which the current-collecting flux portion 12 protrudes in the longitudinal direction of the electrode group 2. In addition, in a preferred example of the third modified example, similar to the example in Figures 12 and 13, the groove 23 does not protrude from the lead 17 on either the side from which the current-collecting flux portion 12 protrudes in the longitudinal direction of the electrode group 2 or the side opposite to the side from which the current-collecting flux portion 12 protrudes in the longitudinal direction of the electrode group 2.

[0103] In the example shown in Figures 12 and 13, similar to the first embodiment, the recessed structure 30 is composed of a plurality of recesses 33, and in the recessed structure 30, recess rows 35A and 35B are formed in which the plurality of recesses 33 are arranged along the width direction of the electrode group 2. However, in this modified example, a plurality of recess rows 35A and 35B are formed, and the plurality of recess rows 35A and 35B are offset from each other in the length direction of the electrode group 2. Because of this configuration, in this modified example such as the example shown in Figures 12 and 13, one or more of the plurality of recesses 33 are offset from any of the other recesses 33 in the length direction of the electrode group 2. Therefore, in one or more of the plurality of recesses 33, the distance from the protruding end E1 of the current collection section 12 along the length direction of the electrode group 2 is different from that of any of the other recesses 33.

[0104] Here, among the multiple recesses 33, we define the recess 33M that is furthest from the protruding end E1 of the current flux collection section 12 (the most distal recess) and the recess 33N that is closest to the protruding end E1 of the current flux collection section 12 (the nearest recess) 33N. In a configuration such as this modified example, where one or more of the multiple recesses 33 are offset in the longitudinal direction of the electrode group 2 relative to any of the other recesses 33, there are at least one of each of the multiple recesses 33M and 33N. Furthermore, depending on the arrangement of the multiple recesses 33 constituting the recessed structure 30, there may be multiple instances of at least one of the recesses 33M and 33N. In the example shown in Figures 12 and 13, in the recessed structure 30, the three recesses 33 that form the recess row 35A become the recess (most distal recess) 33M, and the three recesses 33 that form the recess row 35B become the recess (nearest recess) 33N. Furthermore, the recess (most distal recess) 33M is also referred to as the "first recess," and the recess (newest recess) 33N is also referred to as the "second recess."

[0105] In this modified example, the groove bottom 26 of the groove 23 is adjacent to the recessed structure 30 from the side opposite to the side from which the current-collecting flux portion 12 protrudes in the longitudinal direction. Therefore, it is adjacent to one or more recesses 33 that become the recess (most distal recess) 33M from the side opposite to the side from which the current-collecting flux portion 12 protrudes. The groove 23 then protrudes toward the side opposite to the side from which the current-collecting flux portion 12 protrudes (towards the inside in the longitudinal direction of the electrode group 2) toward one or more recesses 33 that become the recess 33M. In the example shown in Figures 12 and 13, the groove bottom 26 of the groove 23 is adjacent to each of the three recesses 33 that form the recess row 35A from the side opposite to the side from which the current-collecting flux portion 12 protrudes.

[0106] Therefore, in this modified example as well, the groove bottom 26 extends in the region on the inner side of the length of the electrode group 2 (opposite the side from which the current-collecting flux portion 12 protrudes) from the end of the recessed structure 30 opposite to the side from which the current-collecting flux portion 12 protrudes. In the recessed structure 30, for example, the position through which the imaginary line α3 (see Figure 12) passes is the end opposite to the side from which the current-collecting flux portion 12 protrudes. Also, in a preferred example such as the example in Figures 12 and 13, as described above, the groove 23 does not protrude from the lead 17 toward the side opposite to the side from which the current-collecting flux portion 12 protrudes in the length of the electrode group 2. For this reason, in a preferred example, the groove bottom 26 extends between the plate edge 31 of the lead 17 and the end of the recessed structure 30 through which the imaginary line α3 passes.

[0107] Furthermore, in a preferred example of this modified form, the groove 23 does not protrude toward the side where the current-collecting flux portion 12 protrudes toward the recessed structure 30, and the groove 23 does not protrude toward the side where the current-collecting flux portion 12 protrudes toward (outside in the longitudinal direction of the electrode group 2) toward one or more recesses 33 that form the recess (nearest recess) 33N. In the example shown in Figures 12 and 13, the groove 23 does not protrude toward the side where the current-collecting flux portion 12 protrudes toward any of the three recesses 33 that form the recess row 35B. In the recessed structure 30 of this modified form, for example, the position through which the imaginary line α4 (see Figure 12) passes is the end on the side where the current-collecting flux portion 12 protrudes.

[0108] Furthermore, in this modified example, as well as in the example shown in Figures 12 and 13, the groove portion 23 (groove bottom portion 26) does not protrude in the width direction of the electrode group 2 relative to the recessed structure portion 30. For this reason, the groove portion 23 is not formed in the region outside the width direction of the electrode group 2 relative to the recessed structure portion 30. In the recessed structure portion 30 of this modified example, for example, the position through which the imaginary line γ3 (see Figure 12) passes becomes one end in the width direction of the electrode group 2, and the position through which the imaginary line γ4 (see Figure 12) passes becomes the other end in the width direction of the electrode group 2. In the preferred example, the groove portion 23 does not protrude outward in the width direction of the electrode group 2 relative to each of the imaginary lines γ3 and γ4. In the example shown in Figures 12 and 13, the groove portion 23 does not protrude on either side in the width direction relative to either of the recessed rows 35A and 35B.

[0109] As described above, even in a preferred example of this modification, such as the example shown in Figures 12 and 13, in a configuration where the groove bottom 26 of the groove 23 is adjacent to the recessed structure 30 from the side opposite to the side on which the current-collecting flux portion 12 protrudes in the longitudinal direction, the groove 23 (groove bottom 26) protrudes only from the recessed structure 30 on the side opposite to the side on which the current-collecting flux portion 12 protrudes. Furthermore, the groove 23 does not protrude from the recessed structure 30 on the side on which the current-collecting flux portion 12 protrudes, nor on either side in the width direction.

[0110] Furthermore, in this modified example, the groove bottom 26 of the groove portion 23 extends between adjacent rows of recesses 35A and 35B in the longitudinal direction of the electrode group 2. Therefore, in this modified example, the plurality of recesses 33 constituting the recessed structure 30 comprises two or more recesses 33 that are spaced apart in the longitudinal direction of the electrode group 2. The groove bottom 26 of the groove portion 23 extends between two or more recesses 33 that are spaced apart in the longitudinal direction.

[0111] Figure 14 is a schematic perspective view showing an example of the configuration of the joining tip portion 47 of the joining jig 41 according to the third modified example. As shown in Figure 14, in this modified example as well, the base portion 56 forms the protruding end of the protruding base portion 52 that protrudes from the base portion 51, and each of the one or more protrusions 53 of the convex structure portion 50 further protrudes from the base portion 56 toward the protruding direction of the protruding base portion 52. The joining jig 41 is used to join the current collection flux portion 12 to the lead 17. In the joining jig 41 used for joining, the base portion 56 is adjacent to the convex structure portion 50 (row of protrusions 63) from the side facing the depth-direction side portion (first side portion) 57 of the protruding base portion 52. Then, the joining is carried out in the same manner as in the embodiments described above, and at the joining portion of the lead 17 and the current collection flux portion 12, the groove bottom 26 of the groove portion 23 is formed in the portion that the base portion 56 is in contact with, and recesses 33 are formed in each of the portions that one or more protrusions 53 of the convex structure portion 50 are in contact with.

[0112] In the third modified example, in a preferred example, during joining, the base portion 56 and one or more protrusions 53 are brought into contact with the joining target portion, such that the base portion 56 does not protrude from the lead 17 on the side where the longitudinal current-collecting flux portion 12 of the electrode group 2 protrudes, and on the side opposite to where the longitudinal current-collecting flux portion 12 of the electrode group 2 protrudes. In the example shown in Figure 14, similar to the first embodiment, the convex structure portion 50 is composed of a plurality of protrusions 53, and in the convex structure portion 50, rows of protrusions 63A and 63B are formed in which the plurality of protrusions 53 are arranged along the width direction of the protruding base portion 52.

[0113] However, in this modified example, multiple rows of protrusions 63A and 63B are formed, and these rows of protrusions 63A and 63B are offset from each other in the depth direction of the protruding base portion 52. Due to this configuration, in this modified example, such as the one shown in Figure 14, one or more of the multiple protrusions 53 are offset from any of the other protrusions 53 in the depth direction of the protruding base portion 52. Therefore, for one or more of the multiple protrusions 53, the distance between them and the base side portion 57 along the depth direction of the protruding base portion 52 is different from that of any of the other protrusions 53.

[0114] Here, among the multiple protrusions 53, we define the protrusion 53M closest to the base lateral portion (first base lateral portion) 57 (nearest protrusion) and the protrusion 53N furthest from the base lateral portion 57 (farthest protrusion). In a configuration like this modified example, where one or more of the multiple protrusions 53 are offset in the depth direction of the protruding base portion 52 relative to any of the other protrusions 53, there is one or more of each of the multiple protrusions 53M and 53N. Furthermore, depending on the arrangement of the multiple protrusions 53 constituting the convex structure portion 50, there may be multiple instances of at least one of the protrusions 53M and 53N. In the example shown in Figure 14, in the convex structure portion 50, the three protrusions 53 forming the row of protrusions 63A become the protrusion (nearest protrusion) 53M, and the three protrusions 53 forming the row of protrusions 63B become the protrusion (farthest protrusion) 53N. Note that the protrusion 53M is also referred to as the "first protrusion," and the protrusion 53N is also referred to as the "second protrusion." Furthermore, among the multiple protrusions 53, protrusion 53M is furthest from the side portion of the table (second side portion of the table) 58, while protrusion 53N is closest to the side portion of the table 58.

[0115] In this modified example, the base portion 56 is adjacent to the convex structure portion 50 from the side facing the base side portion (first base side portion) 57 in the depth direction of the protruding base portion 52. Therefore, it is adjacent to one or more protrusions 53 that become projections (nearest projections) 53M from the side facing the base side portion 57. The base portion 56 then extends outwards toward the one or more protrusions 53 that become projections 53M toward the side facing the base side portion 57. In the example shown in Figure 14, the base portion 56 is adjacent to each of the three protrusions 53 that form the row of protrusions 63A from the side facing the base side portion 57. Thus, in this modified example as well, the base portion 56 extends toward the area facing the base side portion 57 toward the end of the convex structure portion 50 toward the side facing the base side portion 57. In the convex structure 50 of this modified example, for example, the position through which the imaginary line β3 (see Figure 14) passes is the end on the side facing the base lateral portion 57.

[0116] Furthermore, in a preferred example of this modified form, the base portion 56 does not protrude toward the side of the base lateral portion (second base lateral portion) 58 relative to the convex structure portion 50, and the base portion 56 does not protrude toward the side of the base lateral portion 58 relative to one or more protrusions 53 that become the projection (most distal projection) 53N. In the example shown in Figure 14, the base portion 56 does not protrude toward any of the three protrusions 53 that form the row of protrusions 63B relative to the side of the base lateral portion 58 in the depth direction of the protruding base portion 52. In the convex structure portion 50 of this modified form, for example, the position through which the imaginary line β4 (see Figure 14) passes is the end on the side of the base lateral portion 58 that it faces. Furthermore, in this modified example, in each of the one or more protrusions 53 that become the projection 53N, the projection lateral portion (second projection lateral portion) 62 is connected to the base lateral portion (second base lateral portion) 58 of the projection base portion 52 without the base portion 56 being interposed between them.

[0117] Furthermore, in this modified example, as well as in the example shown in Figure 14, the base portion 56 does not protrude in the width direction of the protruding base portion 52 relative to the convex structure portion 50. Therefore, the base portion 56 is not formed in the area outside the width direction of the protruding base portion 52 relative to the convex structure portion 50. In the convex structure portion 50 of this modified example, for example, the position through which the imaginary line ε3 (see Figure 14) passes becomes one end of the protruding base portion 52 in the width direction, and the position through which the imaginary line ε4 (see Figure 14) passes becomes the other end of the protruding base portion 52 in the width direction. In the preferred example, the base portion 56 does not protrude outward in the width direction of the protruding base portion 52 relative to each of the imaginary lines ε3 and ε4. In the example shown in Figure 14, the base portion 56 does not protrude on either side in the width direction relative to either of the rows of protrusions 63A and 63B.

[0118] As mentioned above, even in a preferred example of this modification, such as the example in Figure 14, in a configuration where the base portion 56 is adjacent to the convex structure portion 50 from the side of the base lateral portion (first base lateral portion) 57 in the depth direction of the protruding base portion 52, the base portion 56 protrudes only toward the side of the base lateral portion 57 relative to the convex structure portion 50. Furthermore, the base portion 56 does not protrude toward the side of the base lateral portion (second base lateral portion) 58 relative to the convex structure portion 50, nor toward either side in the width direction of the protruding base portion 52.

[0119] Furthermore, in this modified example, the base portion 56 extends between adjacent rows of protrusions 63A and 63B in the depth direction of the protruding base portion 52. Therefore, in this modified example, the multiple protrusions 53 constituting the convex structure portion 50 consist of two or more protrusions 53 that are spaced apart in the depth direction of the protruding base portion 52. The base portion 56 extends between two or more protrusions 53 that are spaced apart in the depth direction.

[0120] This modified example also produces the same functions and effects as the embodiments described above. In this modified example, a joining jig 41 is used for joining in which a base portion 56 extends between two or more projections 53 that are spaced apart in the depth direction of the protruding base portion 52. As a result, at the joining portion, the groove bottom portion 26 of the groove portion 23 extends between two or more recesses 33 that are spaced apart in the longitudinal direction of the electrode group 2. By performing the joining with the base portion 56 in contact with the parts to be joined between the spaced-apart recesses 33, the joining strength at the joining portion is further improved.

[0121] In one modified example, in the recessed structure 30, three or more rows of recesses 35 are formed, each consisting of multiple recesses 33 arranged along the width direction of the electrode group 2. In this case as well, one or more of the multiple recesses 33 are positioned offset in the longitudinal direction of the electrode group 2 relative to any of the other recesses 33. In this modified example as well, the recesses 33M and 33N are defined in the same manner as in the third modified example. Then, in the same manner as in any of the examples described above in the third modified example, a groove 23 and one or more recesses 33 are formed at the joint between the current flux collector 12 and the lead 17. However, in all cases, the groove bottom 26 of the groove 23 is adjacent to the recessed structure 30 from the side opposite to the side on which the current flux collector 12 protrudes in the longitudinal direction of the electrode group 2, and is adjacent to the recess 33M from the side opposite to the side on which the current flux collector 12 protrudes.

[0122] Furthermore, in this modified example, the joining jig 41 has three or more rows of protrusions 63, each row of protrusions 53 arranged along the width direction of the protruding base portion 52. In this case as well, one or more of the multiple protrusions 53 are positioned offset in the depth direction of the protruding base portion 52 relative to any of the other protrusions 53. In this modified example as well, the protrusions 53M and 53N are defined in the same manner as in the third modified example. Then, in the same manner as in any of the examples described above in the third modified example, a base portion 56 and one or more protrusions 53 are formed on the joining tip portion 47. However, in all cases, the base portion 56 is adjacent to the convex structure portion 50 from the side facing the depth direction of the protruding base portion 52 (the first base portion) 57, and adjacent to the protrusion 53M from the side facing the base portion 57.

[0123] Furthermore, in one modified example, in a configuration where a row of recesses 35, in which multiple recesses 33 are arranged along the width direction of the electrode group 2, is not formed in the recessed structure 30, one or more of the multiple recesses 33 are positioned offset in the longitudinal direction of the electrode group 2 relative to any of the other recesses 33. In this modified example as well, the recesses 33M and 33N are defined in the same manner as in the third modified example. Then, in the third modified example as in any of the examples described above, a groove 23 and one or more recesses 33 are formed at the joint between the current flux collector 12 and the lead 17. However, in all cases, the groove bottom 26 of the groove 23 is adjacent to the recessed structure 30 from the side opposite to the side on which the current flux collector 12 protrudes in the longitudinal direction of the electrode group 2, and adjacent to the recess 33M from the side opposite to the side on which the current flux collector 12 protrudes.

[0124] Furthermore, in this modified example, a row of protrusions 63, in which multiple protrusions 53 are arranged along the width direction of the protruding base portion 52, is not formed on the joining jig 41. However, even in this modified example, one or more of the multiple protrusions 53 are positioned offset in the depth direction of the protruding base portion 52 relative to any of the other protrusions 53, and the protrusions 53M and 53N are defined in the same manner as in the third modified example. Then, in the same manner as in any of the examples described above in the third modified example, a base portion 56 and one or more protrusions 53 are formed on the joining tip portion 47. However, in all cases, the base portion 56 is adjacent to the convex structure portion 50 from the side facing the depth direction of the base side portion (first base side portion) 57 of the protruding base portion 52, and is adjacent to the protrusion 53M from the side facing the base side portion 57.

[0125] In one modified example, the plurality of recesses 33 forming the concave structure 30 comprises two or more recesses 33 that are spaced apart in both the longitudinal and width directions of the electrode group 2. The groove bottom 26 of the groove 23 extends between the two or more spaced recesses 33. In this modified example, the plurality of protrusions 53 forming the convex structure 50 of the joining jig 41 comprises two or more protrusions 53 that are spaced apart in both the depth and width directions of the protruding base 52. The base 56 extends between the two or more spaced protrusions 53.

[0126] Therefore, in one example of the embodiment, two or more of the recesses 33 forming the concave structure 30 are spaced apart in at least one of the longitudinal and width directions of the electrode group 2, and the groove bottom 26 of the groove 23 extends between the two or more spaced recesses 33. Then, two or more of the protrusions 53 forming the convex structure 50 are spaced apart in at least one of the depth and width directions of the protruding base 52, and the base 52 extends between the two or more spaced protrusions 53.

[0127] In one modified example, multiple current-collecting flux portions 12 are formed on each of the pair of unpainted portions 11. In this case, the multiple current-collecting flux portions 12 are formed spaced apart from each other in the thickness direction of the electrode group 2 on each of the pair of unpainted portions 11. Even when multiple current-collecting flux portions 12 are formed on each of the unpainted portions 11, each current-collecting flux portion 12 protrudes to one side in the length direction of the electrode group 2, and the multiple current-collecting strip portions 13 are stacked on each current-collecting flux portion 12 in the thickness direction of the electrode group 2. In this modified example, each of the leads 17 is provided with multiple leg plates 22, and each of the leads 17 is provided with the same number of leg plates 22 as the current-collecting flux portions 12 formed on the unpainted portion 11 to which it is connected. In this modified example, each current-collecting flux portion 12 is joined to the corresponding one of the pair of leads 17 by the corresponding one of the leg plates 22. In this modified example, each of the current-collecting flux sections 12 is joined to the leg plate section 22 in the same manner as in any of the embodiments described above.

[0128] In one modified example, the battery 1 is not provided with a clip 18, and no clips 18 are attached to each of the current-collecting flux portions 12. In this case, at each of the unpainted portions 11, the current-collecting flux portion 12 is directly joined (connected) to the corresponding end of a pair of leads 17. In this modified example, a groove 23 opens on the outer surface of the current-collecting flux portion 12 on the side opposite to the side where the leads 17 in the thickness direction of the electrode group 2 are stacked. In this modified example as well, each of the current-collecting flux portions 12 is joined to a lead 17, similar to any of the embodiments described above.

[0129] Furthermore, in the embodiments described above, the exterior part 3 is composed of an outer container 5 and a lid member 6, but the composition of the exterior part 3 is not limited to this. In one modified example, the exterior part 3 is composed of a laminate film.

[0130] Furthermore, in one example such as Figure 1, the pair of unpainted portions 11 protrude in opposite directions relative to each other in the longitudinal direction of the electrode group 2, but this is not the only example. In one modified example, in the electrode group 2, the unpainted negative electrode portion protrudes toward the side toward the unpainted positive electrode portion that protrudes in the longitudinal direction. In this case, the pair of unpainted portions 11 are arranged apart from each other in the width direction of the electrode group 2 and do not come into contact with each other. In one example of this modified example, the electrode group 2 is placed in the internal cavity 10 of the outer container 5 such that the thickness direction of the electrode group 2 is aligned with the depth direction of the battery 1, the longitudinal direction of the electrode group 2 is aligned with the height direction of the battery 1, and the width direction of the electrode group 2 is aligned with the lateral direction of the battery 1. In the internal cavity 10, the pair of unpainted portions 11 (unpainted positive electrode portion and unpainted negative electrode portion) protrude toward the side toward the lid member 6 located in the height direction of the battery 1. In this modified example, as in any of the embodiments described above, the current-collecting flux portion 12 is joined to the lead 17 in each of the unpainted portions 11.

[0131] In all of the above-mentioned modifications, at the joint portion of the current-collecting flux portion 12 to the lead 17, the groove bottom portion 26 of the groove portion 23 is adjacent to the concave structure portion 30 from the side opposite to the side from which the current-collecting flux portion 12 protrudes in the longitudinal direction of the electrode group 2. Furthermore, in the joining jig 41 used to join the current-collecting flux portion 12 to the lead 17, the base portion 56 is adjacent to the convex structure portion 50 from the side from which the depth-direction side portion (first side portion) 57 of the protruding base portion 52 faces.

[0132] Furthermore, in electrode group 2, at least one of the pair of unpainted portions 11, that is, at least one of the positive electrode unpainted portion and the negative electrode unpainted portion, may be joined to the lead 17 in the same manner as in any of the embodiments described above. In other words, one or more of the pairs or more current-collecting flux portions 12 formed in electrode group 2 may be joined to the lead 17 in the same manner as in any of the embodiments described above.

[0133] According to at least one embodiment or example, the groove is recessed to the bottom of the groove on the side where the lead is located in the thickness direction at the joint portion between the lead and the current collector, and each of the one or more recesses of the recessed structure is further recessed from the bottom of the groove toward the side where the lead is located. The bottom of the groove is adjacent to the recessed structure from the side opposite to the side where the current collector is protruding in the length direction. This makes it possible to provide a battery, a joining jig, a joining device, and a method for manufacturing a battery in which a proper joint can be ensured at the joint portion between the lead and the current collector at the part adjacent to the recessed structure on the side opposite to the side where the current collector is protruding.

[0134] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0135] 1...Battery, 2...Electrode group, 3...Outer casing, 11...Unpainted part, 12...Current collection bundle part, 13...Current collection strip part, 17...Lead, 23...Groove part, 26...Groove bottom part, 30...Concave structure part, 33...Recess, 40...Bonding device, 41...Bonding jig, 42...Stage, 43...Ultrasonic transducer, 45...Pressure part, 50...Convex structure part, 51...Base part, 52...Protruding base part, 53...Protrusion, 55...Base surface, 56...Pedestal part, 57...Base side part (first base side part), 58...Base side part (second base side part), E1...Protruding end.

Claims

1. A group of electrodes having a current-collecting portion that protrudes to one side in the longitudinal direction, A lead that is conductive and is joined to the current-collecting flux portion, stacked on top of the electrode group from one side in the thickness direction intersecting the length direction, The groove has a bottom portion, and at the joint portion between the lead and the current-collecting flux portion, the groove is recessed to the bottom portion on the side where the lead is located in the thickness direction, The groove portion has one or more recesses that are further recessed from the bottom of the groove portion toward the side where the lead is located, and the groove portion has a recessed structure adjacent to the bottom of the groove portion toward the side opposite to the side from which the current-collecting flux portion protrudes in the longitudinal direction, A battery that is equipped with the following.

2. The battery according to claim 1, wherein the groove portion does not protrude from the lead on the side on which the current-collecting flux portion in the longitudinal direction protrudes, and on the side opposite to the side on which the current-collecting flux portion in the longitudinal direction protrudes.

3. The battery according to claim 1 or 2, wherein the groove portion does not protrude toward the side toward the side toward which the current-collecting flux portion in the longitudinal direction protrudes relative to the concave structure portion.

4. The battery according to claim 1 or 2, wherein the groove portion does not protrude in the width direction of the electrode group that intersects both the length direction and the thickness direction with respect to the concave structure portion.

5. The recessed structure comprises a plurality of recesses, one or more of which are recesses. The plurality of recesses comprises two or more recesses that are spaced apart from each other in at least one of the longitudinal direction and the width direction of the electrode group that intersects both the longitudinal direction and the thickness direction. The bottom of the groove extends between the two or more recesses that are spaced apart. The battery according to claim 1 or 2.

6. The base and, A protruding base portion that protrudes from the base portion, comprising a base portion that forms a protruding end from the base portion, and a first base side portion that extends from the base portion toward the protruding direction, facing one side in the depth direction intersecting the protruding direction, The protruding base portion is provided with one or more protrusions that further protrude from the base portion toward the protruding direction, and the base portion is adjacent to a convex structure portion on the side facing the first base side portion in the depth direction of the protruding base portion, A joining jig equipped with the following features.

7. The protruding base portion includes a second base portion that extends from the base portion toward the protruding direction, facing the opposite side from the side facing the first base portion in the depth direction. The base portion does not protrude from the protruding base portion toward the side of the second base side portion in the depth direction toward the protruding base portion. The joining jig according to claim 6.

8. The joining jig according to claim 6, wherein the base portion of the protruding base portion does not protrude in the width direction of the protruding base portion, intersecting both the protruding direction and the depth direction with respect to the convex structure portion.

9. The base portion comprises a base surface facing the direction of protrusion. The protruding base portion includes a second base portion that extends from the base surface of the base portion toward the protruding direction, facing the opposite side from the side facing the first base portion in the depth direction. The base surface is located on the side of the second base side portion in the depth direction relative to the convex structure portion, The projection length along the projection direction from the base surface of the base to the projection end of one or more protrusions of the convex structure is greater than the projection length along the projection direction from the base portion of the projection base to the projection end of one or more protrusions of the convex structure. The joining jig according to claim 6.

10. The aforementioned convex structure comprises a plurality of protrusions, one or more of which are projections. The plurality of protrusions include two or more protrusions that are spaced apart from each other in at least one of the depth direction and the width direction of the protruding base portion that intersects both the protruding direction and the depth direction. The base portion of the protruding base extends between the two or more projections that are spaced apart. The joining jig according to claim 6.

11. A joining jig according to any one of claims 6 to 10, In joining an electrode group to a lead of a current-collecting flux portion that protrudes to one side in the longitudinal direction, the lead is stacked on the current-collecting flux portion from one side in the thickness direction of the electrode group intersecting the longitudinal direction, and the joining target portion in which the current-collecting flux portion and the lead are stacked is sandwiched between the joining jig, and a stage that contacts the joining target portion from the side in the thickness direction where the lead is stacked, With the portion to be joined sandwiched between the joining jig and the stage, pressure is applied to at least one of the joining jig and the stage so that the first side of the base faces away from the side from which the current-collecting flux portion in the longitudinal direction protrudes, and the one or more protrusions of the base portion and the convex structure portion of the joining jig come into contact with the portion to be joined. With the portion to be joined sandwiched between the joining jig and the stage, an ultrasonic transducer transmits ultrasonic vibrations to the portion to be joined through the joining jig, A joining device equipped with the following:

12. In an electrode group in which the current-collecting flux portion protrudes to one side in the longitudinal direction, leads are stacked on the current-collecting flux portion from one side in the thickness direction of the electrode group that intersects the longitudinal direction, The protruding end of the protruding base portion that protrudes from the base portion is formed by the base portion, and each of the one or more protrusions of the convex structure portion further protrudes from the base portion toward the protruding direction of the protruding base portion, and the joining of the current collection flux portion and the lead portion stacked together is performed using a joining jig, wherein the first side portion of the protruding base portion faces one side of the depth direction of the protruding base portion that intersects with the protruding direction, and the joining is performed using the joining jig adjacent to the convex structure portion from the side toward which the first side portion of the depth direction faces. In joining the portions to be joined, with the first base side facing away from the side from which the current-collecting flux portion in the longitudinal direction protrudes, one or more protrusions of the base portion and the convex structure portion of the joining jig are brought into contact with the portions to be joined from the side opposite to the side from which the leads in the thickness direction are stacked. A method for manufacturing a battery, comprising the following:

13. The manufacturing method of claim 12, wherein, in contact between the base portion and the one or more protrusions and the portion to be joined, the base portion and the one or more protrusions are brought into contact with the portion to be joined, such that the base portion does not protrude relative to the lead on the side from which the current-collecting flux portion protrudes in the longitudinal direction and on the side opposite to the side from which the current-collecting flux portion protrudes in the longitudinal direction.

14. The manufacturing method according to claim 12 or 13, wherein the joining jig used for joining the parts to be joined is such that the second side portion of the protruding base portion faces the opposite side to the side of the first side portion of the base portion in the depth direction, and the base portion does not protrude with respect to the convex structure portion toward the side of the second side portion of the protruding base portion in the depth direction.

15. The manufacturing method of claim 12 or 13, wherein the joining jig used for joining the parts to be joined, the base portion does not protrude in the width direction of the protruding base portion that intersects both the protruding direction and the depth direction with respect to the convex structure portion.

Images