Battery pack for power tools and method of manufacturing same

Abstract

To provide a novel battery pack that employs a pouch-type battery cell.SOLUTION: A battery pack includes a pouch-shaped battery cell arranged to be stacked along a first direction, a substrate arranged in the second direction with respect to the plurality of pouch-shaped battery cells and to which positive electrode tabs and negative electrode tabs of the plurality of pouch-shaped battery cells are connected, a frame having the substrate mounted thereon and looping around the plurality of pouch-shaped battery cells along the substrate, a sealing material filled in the area surrounded by the frame and sealing the positive electrode tabs and the negative electrode tabs extending from the plurality of pouch-shaped battery cells to the substrate, and a housing containing the plurality of pouch-type battery cells, the substrate, and the frame.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to battery packs for power tools and methods of manufacturing the same. [Background technology]

[0002] Patent Document 1 describes a battery pack for power tools. In this battery pack, a plurality of pouch-type battery cells are stacked in one direction. Each pouch-type battery cell has a positive electrode tab and a negative electrode tab, and all of the positive electrode tabs and negative electrode tabs are connected to a substrate. The substrate and the positive electrode tabs and negative electrode tabs connected thereto are sealed by a sealant inside a housing. This configuration can prevent a short circuit from occurring inside the battery pack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-205251 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery pack described above, the substrate, the pouch-type battery cells, and the housing that contains them are fixed together by a sealing material. This configuration can improve the water resistance of the battery pack. However, there is a problem in that an external force applied to the housing is easily transmitted to the substrate and the pouch-type battery cells through the sealing material. [Means for solving the problem]

[0005] In view of the above, this specification discloses a novel battery pack, which includes a plurality of pouch-type battery cells stacked along a first direction, each having a positive electrode tab and a negative electrode tab protruding in a second direction perpendicular to the first direction, a substrate arranged in the second direction relative to the plurality of pouch-type battery cells, to which the positive electrode tab and the negative electrode tab of each of the plurality of pouch-type battery cells are connected, a frame to which the substrate is attached and which surrounds the plurality of pouch-type battery cells along the substrate, a sealant filling an area surrounded by the frame and sealing the positive electrode tabs and the negative electrode tabs extending from the plurality of pouch-type battery cells to the substrate, and a housing accommodating the plurality of pouch-type battery cells, the substrate, and the frame.

[0006] In the above-mentioned configuration, the positive and negative electrode tabs of the multiple pouch-type battery cells are connected to the substrate. The positive and negative electrode tabs connected to the substrate are surrounded by a frame that goes around the substrate. The area surrounded by the frame is filled with a sealant, and the positive and negative electrode tabs are sealed by the sealant. This configuration can prevent short circuits from occurring inside the battery pack. The multiple pouch-type battery cells, the substrate, and the frame, including the sealant, are housed inside the housing. This configuration can prevent the sealant from directly contacting the housing, and a gap can be provided between the housing and the substrate or the frame. As a result, even when an external force is applied to the housing, the external force can be prevented from being transmitted to the substrate and the pouch-type battery cells.

[0007] This specification further discloses a novel method for manufacturing a battery pack. The method includes a step of preparing a semi-finished product. The semi-finished product includes a plurality of pouch-type battery cells arranged in a stacked manner along a first direction, each having a positive electrode tab and a negative electrode tab protruding in a second direction perpendicular to the first direction, a substrate arranged in the second direction relative to the plurality of pouch-type battery cells, the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells being connected, and a frame to which the substrate is attached and which surrounds the plurality of pouch-type battery cells along the substrate. The method further includes a step of arranging the semi-finished product such that an area surrounded by the frame is located above the substrate, filling the area surrounded by the frame with a flowable material, a step of hardening the material to form an encapsulant that encapsulates the positive electrode tabs and the negative electrode tabs extending from the plurality of pouch-type battery cells to the substrate, and a step of housing the plurality of pouch-type battery cells, the substrate, and the frame together with the encapsulant in a housing. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view showing the appearance of the battery pack 10. [Diagram 2] FIG. 2 is an exploded perspective view of the battery pack 10. [Diagram 3] FIG. 2 is an exploded perspective view of a cell unit 30. [Figure 4] FIG. [Diagram 5] Cross-sectional view taken along line VV in Figure 4. [Figure 6] A modified example of a lead plate 80x is shown in a cross-sectional view taken at the same position as in FIG. [Figure 7] FIG. 4 is a perspective view showing the frame 50 and the sub-board 70. [Figure 8] FIG. 8 is an enlarged view of part VIII in FIG. [Figure 9] FIG. [Figure 10] 2 shows the flow of cooling air in the battery pack 10. [Figure 11] 4 shows the reverse flow of cooling air in the battery pack 10. [Figure 12] A modified internal air inlet 34 is shown. [Figure 13] A modification of the flow guide wall 38 is shown. [Figure 14] 3A to 3C are diagrams showing a step in a manufacturing method of the battery pack 10. [Figure 15] 3A to 3C are diagrams showing a step in a manufacturing method of the battery pack 10. [Figure 16] 3A to 3C are diagrams showing a step in a manufacturing method of the battery pack 10. [Figure 17] 3A to 3C are diagrams showing a step in a manufacturing method of the battery pack 10. [Figure 18] FIG. 13 is a perspective view showing a sub-substrate 170 according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In an embodiment of the present technology, the sealing material may be a potting material or a photocurable material, that is, the sealing material may be a material that is cured by drying or by exposure to light.

[0010] In one embodiment of the present technology, the frame may have a frame surface that contacts the substrate and is provided along the periphery of the substrate. With this configuration, the substrate is stably supported by the frame. In addition, when manufacturing a battery pack, leakage of the sealant before curing from a gap between the substrate and the frame can be suppressed.

[0011] In one embodiment of the present technology, a sheet material that is softer than the frame and the substrate may be interposed between the frame surface of the frame and the substrate. With this configuration, leakage of the sealant before hardening from a gap between the substrate and the frame can be further suppressed.

[0012] In one embodiment of the present technology, the frame may have an inner surface facing the plurality of pouch-type battery cells. In this case, the inner surface of the frame may be provided with a plurality of ribs that support each of the plurality of pouch-type battery cells. With this configuration, the plurality of pouch-type battery cells are stably supported by the frame until a sealing material hardens during manufacturing of a battery pack.

[0013] In the above embodiment, each of the plurality of ribs may be located apart from the substrate, and in this configuration, when manufacturing a battery pack, the sealant before curing can flow over a wide area without being hindered by the ribs.

[0014] Additionally or alternatively, each of the ribs may have a notch located inside the sealing material, so that the sealing material can flow over a wide area before curing without being hindered by the ribs during manufacturing of the battery pack.

[0015] In the above embodiment, the frame may have a protrusion between each two of the ribs. In this case, the protrusion may support a corresponding one of the pouch-type battery cells from the second direction. With this configuration, the positional relationship between the pouch-type battery cells and the substrate can be maintained until the sealing material hardens during the manufacture of the battery pack.

[0016] In one embodiment of the present technology, the substrate may have a plurality of tab connection holes. In this case, the positive electrode tab or the negative electrode tab of a corresponding one of the plurality of pouch-type battery cells may be inserted into each of the plurality of tab connection holes. With this configuration, the positive electrode tab and the negative electrode tab of the pouch-type battery cell can be firmly connected to the substrate.

[0017] In one embodiment of the present technology, the substrate may have a first surface facing the plurality of pouch-type battery cells and a second surface located opposite to the first surface. In this case, the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells may each be joined to the substrate at the second surface. With this configuration, the positive electrode tabs and the negative electrode tabs of the pouch-type battery cells can be easily joined to the substrate.

[0018] In one embodiment of the present technology, the positive electrode tabs and the negative electrode tabs of the pouch-type battery cells may be covered with an adhesive on the second surface of the substrate. With this configuration, the substrate is protected from foreign matter and moisture entering from the outside, and the occurrence of defects such as a short circuit in the substrate can be suppressed.

[0019] In one embodiment of the present technology, the battery pack may further include a cell holder located inside the housing and configured to hold the plurality of pouch-type battery cells. In this case, the frame may be attached to the cell holder. With this configuration, the plurality of pouch-type battery cells can be stably held by the frame and the cell holder.

[0020] In one embodiment of the manufacturing method relating to the present technology, the step of preparing the semi-finished product may include a step of inserting the positive electrode tab or the negative electrode tab of a corresponding one of the plurality of pouch-type battery cells into each of a plurality of tab connection holes provided in the substrate.

[0021] In the above embodiment, the substrate may have a first surface facing the plurality of pouch-type battery cells and a second surface located opposite the first surface. In this case, the step of preparing a semi-finished product may further include a step of joining the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells inserted into the plurality of tab connection holes to the second surface.

[0022] In the following, exemplary and non-limiting examples of the present invention will be described in detail with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing the preferred examples of the present invention, and is not intended to limit the scope of the present invention. In addition, the additional features and inventions disclosed below can be used separately or together with other features and inventions to provide further improved battery packs.

[0023] Furthermore, the combinations of features and steps disclosed in the following detailed description are not essential to the practice of the invention in its broadest sense, but are specifically described only to illustrate representative embodiments of the invention. Furthermore, the various features of the representative embodiments described above and below, and the various features of those described in the independent and dependent claims, do not have to be combined in the exact embodiments described herein, or in the exact order listed, to provide additional and useful embodiments of the invention.

[0024] All features described in the specification and / or claims are intended to be disclosed individually and independently of one another as limitations to the original disclosure and claimed particulars, apart from any configuration of features described in the examples and / or claims. Furthermore, all numerical ranges and group or aggregate descriptions are intended to disclose their intermediate configurations as limitations to the original disclosure and claimed particulars. EXAMPLES

[0025] A battery pack 10 according to the embodiment will be described with reference to the drawings. The battery pack 10 according to the embodiment is a battery pack for power tools, and can be suitably used in handheld power tools in particular. The power tool referred to here typically means a power tool having a motor or other actuator. However, the battery pack 10 according to the embodiment may be used in other electric devices in addition to power tools.

[0026] Here, the direction FR in the drawings indicates the front in the front-rear direction, and the direction RR indicates the rear in the front-rear direction, which is the opposite direction to the front. The direction LH in the drawings indicates the left in the left-right direction, and the direction RH indicates the right in the left-right direction, which is the opposite direction to the left. And the direction UP in the drawings indicates the upward direction in the vertical direction, and the direction DW indicates the downward direction in the vertical direction, which is the opposite direction to the upward direction. Note that the front-rear direction, the left-right direction, and the upward direction are defined here for the convenience of explanation, and do not limit the posture of the battery pack 10 during use or during manufacture.

[0027] As shown in Figs. 1 to 3, the battery pack 10 includes a housing 12, a cell unit 30 accommodated inside the housing 12, and a buffer member 28 disposed between the housing 12 and the cell unit 30. The buffer member 28 is made of a rubber material. The housing 12 includes an upper part 12x and a lower part 12y. The housing 12 has a generally rectangular parallelepiped shape and includes a front wall 12a, a rear wall 12b, a left side wall 12c, a right side wall 12d, an upper wall 12e, and a lower wall 12f. The upper wall 12e of the housing 12 is provided with a tool interface 20. The tool interface 20 is configured to be physically and electrically attachable to and detachable from the power tool and the charger.

[0028] As an example, the tool interface 20 in this embodiment has a pair of engagement rails 22 and an electrical connector 24. The pair of engagement rails 22 physically engage with the power tool or charger to fix the battery pack 10 to the power tool or charger. The electrical connector 24 electrically connects to the power tool or charger when the tool interface 20 is attached to the power tool or charger. This electrically connects the battery pack 10 to the power tool or charger. The position and structure of the tool interface 20 are not particularly limited.

[0029] The housing 12 has an intake port 14 and an exhaust port 16. The intake port 14 is located in a front portion of the housing 12, and the exhaust port 16 is located in a rear portion of the housing 12. That is, the intake port 14 is located forward of the exhaust port 16. As a result, inside the housing 12, cooling air flows backward in the front-rear direction. As an example, in this embodiment, the intake port 14 is provided in the front wall 12a, the left side wall 12c, and the right side wall 12d of the housing 12, and the exhaust port 16 is provided in the upper wall 12e of the housing 12. As will be described in detail later, when the battery pack 10 is attached to an external device 200 such as a power tool or a charger, the exhaust port 16 is connected to a blower 202 of the external device 200 (see FIG. 10). As a result, the inside of the battery pack 10 is forcibly ventilated by the blower 202 of the external device 200.

[0030] The cell unit 30 includes a plurality of pouch-type battery cells 100 and an internal housing 32 that houses the plurality of pouch-type battery cells 100. The pouch-type battery cell 100 is a battery cell that houses positive and negative current collector sheets and an electrolyte inside an exterior made of a laminate film. Each pouch-type battery cell 100 has a generally flat shape, and the plurality of pouch-type battery cells 100 are stacked and arranged along the upper side (first direction). Each pouch-type battery cell 100 has a positive electrode tab 102 and a negative electrode tab 104. The positive electrode tab 102 and the negative electrode tab 104 are electrodes of the pouch-type battery cell 100, and are made of a sheet of a conductor such as a metal. In each pouch-type battery cell 100, the positive electrode tab 102 and the negative electrode tab 104 protrude forward (second direction). Although not limited thereto, the pouch-type battery cell 100 in this embodiment is a rechargeable secondary battery cell, in particular a lithium-ion battery cell. Hereinafter, the pouch-type battery cell 100 will be simply referred to as the battery cell 100.

[0031] The cell unit 30 includes a cell holder 40, a frame 50, a main board 60, a sub-board 70, and a connection member 80. The cell holder 40, the frame 50, the main board 60, and the sub-board 70 are assembled together to form an internal housing 32 that houses multiple pouch-type battery cells 100. The internal housing 32 has an internal air intake 34 and an internal exhaust 36. The internal air intake 34 is located forward of the internal exhaust 36. This allows cooling air to flow backward in the front-to-rear direction even inside the internal housing 32. Although this is just an example, the internal air intake 34 and the internal exhaust 36 in this embodiment are provided in the cell holder 40. In more detail, the internal air intake 34 is provided at a position facing the multiple pouch-type battery cells 100 in the left-right direction, and the internal exhaust 36 is located rearward of the multiple pouch-type battery cells 100.

[0032] The main board 60 is disposed above (in a first direction) the multiple battery cells 100. The main board 60 has a power port 26. The power port 26 is located inside the tool interface 20 and electrically connects to an external device 200 such as a power tool or a charger. As an example, the power port 26 in this embodiment has a contact-type external connection terminal made of a conductor. However, the power port 26 may be a wireless power port having, for example, an electromagnetic induction coil. The main board 60 is fixed to the cell holder 40 using multiple screws 61.

[0033] The sub-substrate 70 is disposed in front (in the second direction) of the plurality of battery cells 100. The positive electrode tabs 102 and the negative electrode tabs 104 of the plurality of battery cells 100 are connected to the sub-substrate 70. As a result, the plurality of battery cells 100 are electrically connected to each other by the sub-substrate 70. As will be described in detail later, the sub-substrate 70 in this embodiment is configured to connect the plurality of battery cells 100 in series. However, in another embodiment, the sub-substrate 70 may be configured to connect some or all of the plurality of battery cells 100 in parallel to each other. The sub-substrate 70 is fixed to the frame 50 by using a plurality of screws 71, and is detachably attached to the cell holder 40 via the frame 50. As an example, the frame 50 is fixed to the cell holder 40 by a plurality of screws 51.

[0034] As shown in FIG. 4 and FIG. 5, the connection member 80 extends between the sub-substrate 70 and the main substrate 60, and electrically connects the sub-substrate 70 and the main substrate 60. As a result, the multiple battery cells 100 are electrically connected to the power port 26 via the sub-substrate 70 and the main substrate 60. As an example, the connection member 80 has a pair of lead plates 80x, 80y. The pair of lead plates 80x, 80y includes a positive electrode lead plate 80x and a negative electrode lead plate 80y. Each of the lead plates 80x, 80y is made of a conductor such as a metal. The main substrate 60 extends to above the sub-substrate 70 and intersects with a straight line extending upward (in the first direction) from the sub-substrate 70. As a result, each of the lead plates 80x, 80y extends between the sub-substrate 70 and the main substrate 60 in parallel with the upward direction (in the first direction). With this configuration, the main board 60 and the sub-board 70 can be connected via the shortest possible path.

[0035] However, as shown in FIG. 6, in another embodiment, the main board 60 may not extend above the sub-board 70 and may not intersect with a straight line extending from the sub-board 70 in the first direction (upward). In this case, the lead plates 80x and 80y may extend between the sub-board 70 and the main board 60 at an angle with respect to the upward direction (first direction). Even with such a configuration, the main board 60 and the sub-board 70 can be connected by a relatively short path. Here, the angle that the lead plates 80x and 80y make with respect to the upward direction (first direction) is not particularly limited. The lead plates 80x and 80y may extend linearly or curvedly between the sub-board 70 and the main board 60.

[0036] As shown in FIGS. 4 to 6, the sub-substrate 70 has a plurality of tab connection holes 78. A positive electrode tab 102 or a negative electrode tab 104 of a corresponding one of the plurality of battery cells 100 is inserted into each of the plurality of tab connection holes 78. Here, the sub-substrate 70 has a rear surface 70a facing the plurality of battery cells 100 and a front surface 70b located on the opposite side of the rear surface 70a. Then, each of the positive electrode tabs 102 and the negative electrode tabs 104 of the plurality of battery cells 100 is joined to the sub-substrate 70 at the front surface 70b of the sub-substrate 70. More specifically, each of the positive electrode tabs 102 and the negative electrode tabs 104 is joined to the front surface 70b of the sub-substrate 70 by soldering.

[0037] Although not particularly limited, the multiple pouch-type battery cells 100 are stacked one by one with the front and back inverted. As a result, in each of two adjacent battery cells 100, the positive electrode tab 102 of one battery cell 100 and the negative electrode tab 104 of the other battery cell 100 are adjacent to each other in the up-down direction (i.e., along the first direction). With this configuration, a circuit that connects the multiple battery cells 100 in series can be simply formed on the sub-substrate 70. In other words, the arrangement and individual postures of the multiple battery cells 100 can be designed appropriately according to the circuit to be formed on the sub-substrate 70.

[0038] The sub-substrate 70 in this embodiment has a first conductor line 72 extending intermittently upward, a second conductor line 74 extending intermittently in parallel with the first conductor line 72, and a third conductor line 76 extending upward between the first conductor line 72 and the second conductor line 74. The first conductor line 72 and the second conductor line 74 each have an array of the above-mentioned tab connection holes 78, to which the positive electrode tab 102 or the negative electrode tab 104 of each battery cell 100 is joined. The upper end of the first conductor line 72 is connected to the positive electrode lead plate 80x, and the lower end of the second conductor line 74 is connected to the negative electrode lead plate 80y via the third conductor line 76. On the front surface 70b of the sub-substrate 70, the positive electrode tab 102 and the negative electrode tab 104 of the multiple battery cells 100 are covered with an adhesive 92. The adhesive 92 covers the positive electrode tab 102 and the negative electrode tab 104 as well as the first conductor line 72, the second conductor line 74, and the third conductor line 76.

[0039] With the above configuration, the multiple battery cells 100 are electrically connected in series between the positive electrode lead plate 80x and the negative electrode lead plate 80y. The positive electrode tab 102 of the uppermost battery cell 100 located closest to the main board 60 is connected to the positive electrode lead plate 80x via the first conductor line 72. Meanwhile, the negative electrode tab 104 of the battery cell 100 located farthest from the main board 60 is connected to the negative electrode lead plate 80y via the third conductor line 76.

[0040] The structure of the frame 50 will be described with reference to Figs. 5 to 8. The frame 50 is made of a polymer material such as resin. However, the material of the frame 50 is not particularly limited. As described above, the sub-substrate 70 is attached to the frame 50. The frame 50 has a shape that surrounds the periphery of the multiple battery cells 100 along the sub-substrate 70. The area surrounded by the frame 50 is filled with a sealant 90. The sealant 90 encapsulates the positive electrode tabs 102 and the negative electrode tabs 104 that extend from the multiple battery cells 100 to the sub-substrate 70. This protects the positive electrode tabs 102 and the negative electrode tabs 104, and the sub-substrate 70 to which they are connected, from foreign matter and moisture that enter from the outside, and can suppress the occurrence of a short circuit inside the battery pack 10. Here, the sealant 90 may be made of a potting material or a photocurable material. An example of the photocurable material is an ultraviolet-curable resin.

[0041] The frame 50 is provided with a frame surface 56 that contacts the sub-substrate 70. The frame surface 56 faces forward so as to face the sub-substrate 70, and is provided in an annular shape along the periphery 70c of the sub-substrate 70. With this configuration, the sub-substrate 70 is stably supported by the frame 50. Also, when manufacturing the battery pack 10, it is possible to prevent the sealing material 90 before hardening from leaking from the gap between the sub-substrate 70 and the frame 50. Here, as shown in FIG. 6, a sheet material 57 that is softer than the frame 50 and the sub-substrate 70 may be interposed between the frame surface 56 of the frame 50 and the sub-substrate 70.

[0042] The frame 50 has an inner surface 52 facing the multiple battery cells 100. The inner surface 52 extends in an annular shape so as to surround the multiple battery cells 100. A plurality of ribs 54 are provided on the inner surface 52 of the frame 50. The multiple ribs 54 are arranged along the up-down direction, and each of the ribs 54 extends along the front-rear direction. The multiple ribs 54 support each of the multiple battery cells 100. That is, each battery cell 100 is inserted between two adjacent ribs 54. With this configuration, during the manufacture of the battery pack 10, the multiple battery cells 100 are stably supported by the frame 50 until the sealing material 90 hardens.

[0043] A gap CL is provided between each of the plurality of ribs 54 and the sub-substrate 70. In other words, a gap CL is provided between each of the plurality of ribs 54 and the frame surface 56. In this manner, when each of the plurality of ribs 54 is located away from the sub-substrate 70, the pre-cured sealant 90 can flow over a wide range without being hindered by the ribs 54 when manufacturing the battery pack 10. The gap CL between the rib 54 and the sub-substrate 70 can also be interpreted as a notch provided in the rib 54. Moreover, such a notch may be provided in the middle part in the longitudinal direction of the rib 54 instead of the end part of the rib 54. With such a configuration, the pre-cured sealant 90 can flow over a wide range through the notch.

[0044] The frame 50 further has a protrusion 55 between each two of the multiple ribs 54. The protrusion 55 abuts against a corresponding one of the multiple battery cells 100 to support the battery cell 100 from the front. The specific structure of the protrusion 55 is not particularly limited. The protrusion 55 may be one that abuts against the battery cell 100 from the front, and may, for example, protrude rearward from the opposite side of the frame surface 56, or may protrude upward or downward from the side surface of the rib 54.

[0045] The frame 50 has a rim portion 58 that protrudes forward. The rim portions 58 are provided on the left and right sides of the frame 50. The rim portions 58 extend in the vertical direction along the periphery 70c of the sub-board 70, and cover the periphery 70c of the sub-board 70. With this configuration, the sub-board 70 can be protected by the frame 50. Furthermore, when the sub-board 70 is attached to the frame 50, the rim portions 58 can be used as a guide for positioning the sub-board 70 with respect to the frame 50.

[0046] As shown in FIG. 3 and FIG. 9, the cell holder 40 holds the plurality of battery cells 100 inside the housing 12. The cell holder 40 has an inner surface 42 facing the plurality of battery cells 100. The inner surface 42 of the cell holder 40 is provided with a plurality of ribs 44. Although not particularly limited, in the cell holder 40 in this embodiment, the plurality of ribs 44 are located rearward of the plurality of battery cells 100. That is, they are located on the opposite side of the sub-substrate 70, the positive electrode tab 102, and the negative electrode tab 104 with respect to the plurality of battery cells 100. The plurality of ribs 44 are arranged along the up-down direction, and each rib 44 extends along the left-right direction. The plurality of ribs 44 support the plurality of battery cells 100, respectively. That is, each battery cell 100 is inserted between two adjacent ribs 44.

[0047] The cell holder 40 has a left part 40x and a right part 40y, and accommodates a plurality of battery cells 100 between the left part 40x and the right part 40y. The left part 40x constitutes the left side wall 40a of the cell holder 40 and a part of the rear wall 40c of the cell holder 40. The right part 40y constitutes the right side wall 40b of the cell holder 40 and another part of the rear wall 40c of the cell holder 40. The above-mentioned plurality of ribs 44 are located on the rear wall of the cell holder 40c, and are provided on each of the left part 40x and the right part 40y. As described above, the cell holder 40, together with the main board 60 and the sub-board 70, constitutes the internal housing 32 that accommodates a plurality of battery cells 100. In more detail, at least a part of the upper wall of the internal housing 32 is constituted by the main board 60, and at least a part of the front wall of the internal housing 32 is constituted by the sub-board 70. In this way, by configuring at least a portion of the inner housing 32 using one or more boards 60, 70, it is possible to reduce the space required for arranging those boards 60, 70 and to reduce the weight of the inner housing 32.

[0048] The left side wall 40a and the right side wall 40b of the cell holder 40 each constitute a side wall of the internal housing 32. In this specification, the side wall of the internal housing 32 may be referred to as an internal side wall to distinguish it from the side walls 12c and 12d of the housing 12. The side walls 40a and 40b (i.e., the internal side walls) of the cell holder 40 face the multiple battery cells 100 from the left or right (third direction) perpendicular to the upper side (first direction) and the front side (second direction). The side walls 40a and 40b of the cell holder 40 are provided with the internal air intake 34 described above. The internal air intake 34 has multiple through holes provided in the side walls 40a and 40b of the cell holder 40. The multiple through holes of the internal air intake 34 are arranged along the upper side (first direction), and each through hole is an elongated hole extending along the front side (second direction).

[0049] The side walls 40a, 40b of the cell holder 40 are provided with a flow guide wall 38. The flow guide wall 38 is located between the side walls 40a, 40b of the cell holder 40 and the side walls 12c, 12d of the housing 12 facing the side walls 40a, 40b of the cell holder 40. The flow guide wall 38 protrudes toward the side walls 12c, 12d of the housing 12. The internal air intake 34 is located forward of the flow guide wall 38. With this configuration, the cooling air introduced into the inside of the housing 12 through the air intake 14 can be smoothly guided into the inside of the internal housing 32 through the internal air intake 34.

[0050] Meanwhile, the rear wall 40c of the cell holder 40 is provided with the aforementioned internal exhaust port 36. The internal exhaust port 36 is located at the upper end of the rear wall 40c and opens upward. The rear wall 40c is further provided with an exhaust passage 46 connected to the internal exhaust port 36. The exhaust passage 46 extends in the vertical direction behind the multiple battery cells 100.

[0051] The flow of cooling air in the battery pack 10 will be described with reference to Fig. 10. In Fig. 10, the flow of cooling air is diagrammatically indicated by arrows. As described above, when the battery pack 10 is attached to an external device 200 such as a power tool or a charger, the exhaust port 16 of the housing 12 is connected to the blower 202 of the external device 200. Here, the internal exhaust port 36 of the internal housing 32 is disposed within the exhaust port 16 of the housing 12 and is substantially airtightly connected to the exhaust port 16. The blower 202 blows air in the opposite direction to the battery pack 10, thereby drawing air from inside the battery pack 10.

[0052] When the blower 202 is operated, outside air is introduced into the housing 12 through the intake port 14. Inside the housing 12, cooling air flows backward. At this time, since the intake port 14 is located forward of the sub-substrate 70, the sub-substrate 70 is also effectively cooled by the cooling air. The cooling air inside the housing 12 is introduced into the inside of the internal housing 32 through the internal intake port 34. Since the internal intake port 34 has a plurality of through holes arranged along the vertical direction, the cooling air is evenly distributed to the plurality of battery cells 100 stacked in the vertical direction. Inside the internal intake port 34, the cooling air flows backward and is then exhausted to the outside through the internal exhaust port 36 and the exhaust port 16. Since the internal exhaust port 36 and the exhaust port 16 are located rearward of the plurality of battery cells 100, the cooling air is exhausted to the outside after completely passing through the plurality of battery cells 100.

[0053] As shown in FIG. 11, the blower 202 of the external device 200 may blow air toward the battery pack 10. In this case, the intake port 14 and the exhaust port 16 of the housing 12 function as the exhaust port and the intake port of the housing 12, respectively. Similarly, the internal intake port 34 and the internal exhaust port 36 of the internal housing 32 function as the internal exhaust port and the internal intake port of the internal housing 32, respectively. In this case, the internal intake port (36) is disposed within the intake port (16) and is substantially airtightly connected to the intake port (16). The internal intake port (36) and the intake port (16) are located rearward of the multiple battery cells 100, and inside the housing 12 and the internal housing 32, the cooling air flows forward. The exhaust port (14) of the housing 12 is located forward of the internal exhaust port (34) of the internal housing 32, and is further located forward of the multiple battery cells 100. The internal exhaust port (34) is located on the side walls 40a, 40b of the cell holder 40 and has a plurality of through holes arranged along the up-down direction. Each of the through holes is an elongated hole extending along the front-rear direction.

[0054] FIG. 12 shows a modified example of the internal air intake 34. As shown in FIG. 12, some or all of the multiple through holes of the internal air intake 34 may have different sizes. In this case, as an example, some or all of the multiple through holes may have different dimensions in the front-rear direction. On the other hand, the distance between each of the multiple through holes and the flow guide wall 38 may be equal to each other. Note that, as another embodiment, some or all of the multiple through holes of the internal air intake 34 may have different dimensions in the front-rear direction.

[0055] Fig. 13 shows a modified example of the flow guide wall 38. As shown in Fig. 13, the flow guide wall 38 may be provided in the housing 12 instead of or in addition to the cell holder 40. In this case, the flow guide wall 38 may protrude from the housing 12 toward the cell holder 40, i.e., toward the inner housing 32. Even with this configuration, the cooling air introduced into the housing 12 can be smoothly guided into the inner housing 32 through the inner air intake 34.

[0056] Next, a manufacturing method of the battery pack 10 will be described with reference to Figs. 14 to 16. First, as shown in Fig. 14, a frame 50, a sub-substrate 70, and a plurality of battery cells 100 are assembled together to prepare a semi-finished product 30A of the cell unit 30. In this semi-finished product 30A, a plurality of battery cells 100 are stacked along the upper side (first direction). Each battery cell 100 has a positive electrode tab 102 and a negative electrode tab 104 that protrude forward. The plurality of battery cells 100 are stacked one by one with the front and back reversed. As a result, in each of two adjacent battery cells 100, the positive electrode tab 102 of one battery cell 100 and the negative electrode tab 104 of the other battery cell 100 are adjacent to each other in the up-down direction.

[0057] The positive electrode tabs 102 and the negative electrode tabs 104 of the multiple battery cells 100 are electrically connected to the sub-substrate 70. As described above, the sub-substrate 70 is provided with multiple tab connection holes 78. A corresponding one of the positive electrode tabs 102 or negative electrode tabs 104 of the multiple battery cells 100 is inserted into each of the multiple tab connection holes 78. Then, each of the positive electrode tabs 102 and negative electrode tabs 104 inserted into the multiple tab connection holes 78 is joined to the front surface 70b of the sub-substrate 70. In detail, each of the positive electrode tabs 102 and negative electrode tabs 104 is joined to the first conductor line 72 or the second conductor line 74 provided on the front surface 70b of the sub-substrate 70. The frame 50 goes around the periphery of the multiple battery cells 100 along the sub-substrate 70.

[0058] Next, as shown in FIG. 15, the semi-finished product 30A is arranged so that the area surrounded by the frame 50 is located above the sub-substrate 70. Then, the area surrounded by the frame 50 is filled with a material 91 having fluidity. This material 91 is a material that constitutes the sealing material 90, and may be, for example, a potting material before hardening or a photocurable material. Thereafter, the material 91 having fluidity is hardened to form the sealing material 90 that encapsulates the positive electrode tabs 102 and the negative electrode tabs 104 that extend from the multiple battery cells 100 to the sub-substrate 70. In this way, by using the frame 50 and the sub-substrate 70 as a mold, the sealing material 90 can be easily molded.

[0059] Next, as shown in Fig. 16, a cell holder 40 and a main board 60 are attached to the semi-finished product 30A to complete the cell unit 30. Then, as shown in Fig. 17, the cell unit 30 is housed in the housing 12 together with the buffer member 28. In this way, the battery pack 10 is completed.

[0060] In the battery pack 10 of this embodiment, the first conductor line 72, the second conductor line 74, and the third conductor line 76 of the sub-substrate 70 are composed of a conductor film (more specifically, a copper film) formed on the surface of the sub-substrate 70. However, the first conductor line 72, the second conductor line 74, and the third conductor line 76 may be composed of other conductor members such as a conductor plate or a conductor cable. As an example, FIG. 18 shows a sub-substrate 170 of a modified example. In this sub-substrate 170, at least a part of the third conductor line 76 is composed of a conductor plate attached to the sub-substrate 170. This type of conductor plate is also called a bus bar and has a larger cross-sectional area than the conductor film. In this way, by forming at least a part of the first conductor line 72, the second conductor line 74, and the third conductor line 76 from a conductor plate such as a bus bar, the electrical resistance in the sub-substrate 170 can be reduced.

[0061] Preferred embodiments of a battery pack for an electric power tool that can be understood from the battery pack 10 of the above-mentioned embodiment will be listed below.

[0062] [Embodiment 1-1] a plurality of pouch-type battery cells arranged in a stack along a first direction, each of the pouch-type battery cells having a positive electrode tab and a negative electrode tab protruding in a second direction perpendicular to the first direction; a main board disposed in the first direction relative to the plurality of pouch-type battery cells and having a power port for electrically connecting to an external device; a sub-substrate that is disposed in the second direction with respect to the plurality of pouch-type battery cells and is connected to the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells; a connection member that electrically connects the sub-board and the main board; A battery pack comprising: [Embodiment 1-2] The battery pack of embodiment 1-1, wherein the connection member includes at least one lead plate. [Embodiment 1-3] the main board intersects with a straight line extending from the sub board in the first direction, The battery pack according to embodiment 1-2, wherein the lead plate extends between the sub-board and the main board in parallel with the first direction. [Embodiment 1-4] the main board does not intersect with a straight line extending from the sub board in the first direction, A battery pack according to embodiment 1-2, wherein the lead plate extends between the sub-board and the main board at an angle to the first direction. [Embodiments 1-5] The battery pack according to any one of embodiments 1-1 to 4, further comprising a cell holder for holding the plurality of pouch-type battery cells. [Embodiments 1-6] the cell holder has an inner surface facing the plurality of pouch-type battery cells, A battery pack according to any one of embodiments 1 to 5, wherein the inner surface of the cell holder is provided with a plurality of ribs that respectively support the plurality of pouch-type battery cells. [Embodiments 1-7] A battery pack as described in any one of embodiments 1 to 6, wherein the plurality of ribs are located in a direction opposite to the second direction relative to the plurality of pouch-type battery cells. [Embodiments 1-8] a housing for accommodating the cell holder; The battery pack of any one of embodiments 1 to 6 or 7, further comprising a buffer member disposed between the cell holder and the housing. [Embodiments 1-9] The battery pack according to any one of embodiments 1-5 to 8, wherein the main board is attached to the cell holder. [Embodiments 1-10] The battery pack according to any one of embodiments 1-5 to 9, wherein the sub-substrate is attached to the cell holder. [Embodiments 1-11] the sub-substrate is attached to the cell holder via a frame, A battery pack as described in any one of embodiments 1 to 10, wherein the frame covers at least a portion of the periphery of the sub-substrate. [Embodiments 1-12] the frame has an inner surface facing the plurality of pouch-type battery cells, A battery pack as described in any one of embodiments 1-11, wherein the inner surface of the frame is provided with a plurality of ribs that respectively support the plurality of pouch-type battery cells. [Embodiments 1-13] A battery pack as described in any one of embodiments 1 to 12, wherein the frame is removably attached to the cell holder. [Embodiments 1-14] The battery pack according to any one of embodiments 1-1 to 13, wherein the sub-substrate has a circuit that electrically connects the plurality of pouch-type battery cells. [Embodiments 1-15] 15. The battery pack of any one of embodiments 1-1 to 14, wherein the circuit connects the plurality of pouch-type battery cells in series. [Embodiment 1-16] The plurality of pouch-type battery cells are stacked one by one with the front and back inverted, A battery pack as described in embodiments 1-15, wherein, in each of two adjacent pouch-type battery cells, the positive electrode tab of one pouch-type battery cell and the negative electrode tab of the other pouch-type battery cell are adjacent to each other along the first direction. [Embodiment 1-17] the circuit of the sub-substrate includes a first conductor line extending intermittently along the first direction and a second conductor line extending intermittently in parallel with the first conductor line; A battery pack as described in embodiments 1-16, wherein in each of the plurality of pouch-type battery cells, one of the positive electrode tab and the negative electrode tab is connected to the first conductor line, and the other of the positive electrode tab and the negative electrode tab is connected to the second conductor line. [Embodiment 1-18] the circuit of the sub-substrate further includes a third conductor line extending along the first direction between the first conductor line and the second conductor line, A battery pack according to any one of embodiments 1-17, wherein one of the first conductor line and the second conductor line is connected to the connection member via the third conductor line. [Embodiment 1-19] A battery pack as described in any one of embodiments 1-14, wherein the third conductor line electrically connects between the negative electrode tab of the pouch-type battery cell located farthest from the main board and the connection member. [Embodiment 1-20] 20. The battery pack according to any one of embodiments 1-1 to 19, wherein the power port has a contact-type external connection terminal made of a conductor.

[0063] [Embodiment 2-1] a plurality of pouch-type battery cells arranged in a stack along a first direction, each of the pouch-type battery cells having a positive electrode tab and a negative electrode tab protruding in a second direction perpendicular to the first direction; a substrate disposed in the second direction relative to the plurality of pouch-type battery cells, and to which the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells are connected; a frame to which the substrate is attached and which surrounds the plurality of pouch-type battery cells along the substrate; a sealant that fills an area surrounded by the frame and that encapsulates the positive electrode tabs and the negative electrode tabs that extend from the plurality of pouch-type battery cells to the substrate; a housing that accommodates the plurality of pouch-type battery cells, the substrate, and the frame; A battery pack comprising: [Embodiment 2-2] The battery pack according to embodiment 2-1, wherein the sealing material is made of a potting material or a photocurable material. [Embodiment 2-3] The battery pack according to embodiment 2-1 or 2, wherein the frame has a frame surface that contacts the substrate and is provided along the periphery of the substrate. [Embodiment 2-4] The battery pack according to any one of embodiments 2-1 to 3, wherein a sheet material that is softer than the frame and the substrate is interposed between the frame surface of the frame and the substrate. [Embodiment 2-5] the frame has an inner surface facing the plurality of pouch-type battery cells, The battery pack according to any one of embodiments 2-1 to 4, wherein the inner surface of the frame is provided with a plurality of ribs that respectively support the plurality of pouch-type battery cells. [Embodiment 2-6] A battery pack as described in embodiments 2-5, wherein each of the plurality of ribs is located away from the substrate. [Embodiment 2-7] The battery pack of any one of embodiments 2-5 or 6, wherein each of the plurality of ribs has a notch located inside the sealing material. [Embodiment 2-8] the frame has a protrusion between each two adjacent ones of the plurality of ribs; The battery pack according to any one of embodiments 2-5 to 7, wherein the protrusion supports a corresponding one of the plurality of pouch-type battery cells from the second direction. [Embodiment 2-9] the substrate has a plurality of tab connection holes; The battery pack according to any one of embodiments 2-1 to 8, wherein the positive electrode tab or the negative electrode tab of a corresponding one of the pouch-type battery cells is inserted into each of the tab connection holes. [Embodiment 2-10] the substrate has a first surface facing the plurality of pouch-type battery cells and a second surface located opposite the first surface; A battery pack as described in embodiment 2-10, wherein each of the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells is joined to the substrate on the second surface. [Embodiment 2-11] A battery pack as described in embodiment 2-10, wherein on the second surface of the substrate, the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells are covered with an adhesive. [Embodiment 2-12] a cell holder positioned inside the housing and configured to hold the pouch-type battery cells; 12. The battery pack of any one of embodiments 2-1 to 11, wherein the frame is attached to the cell holder. [Embodiment 2-13] A method for manufacturing a battery cell, comprising: preparing a semi-finished product including: a plurality of pouch-type battery cells stacked along a first direction, each having a positive electrode tab and a negative electrode tab protruding in a second direction perpendicular to the first direction; a substrate arranged in the second direction relative to the plurality of pouch-type battery cells, the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells being connected; and a frame to which the substrate is attached and which surrounds the plurality of pouch-type battery cells along the substrate; placing the semi-finished product such that an area surrounded by the frame is located above the substrate, and filling the area surrounded by the frame with a fluid material; curing the material to form an encapsulant encapsulating the positive and negative tabs extending from the plurality of pouch-type battery cells to the substrate; housing the plurality of pouch-type battery cells, the substrate, and the frame together with the sealing body in a housing; A battery pack comprising: [Embodiment 2-14] The manufacturing method described in embodiments 2-13, wherein the step of preparing the semi-finished product includes a step of inserting the positive electrode tab or the negative electrode tab of a corresponding one of the plurality of pouch-type battery cells into each of a plurality of tab connection holes provided in the substrate. [Embodiment 2-15] the substrate has a first surface facing the plurality of pouch-type battery cells and a second surface located opposite the first surface; The manufacturing method described in embodiment 2-14, wherein the step of preparing the semi-finished product further includes a step of joining each of the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells inserted into the plurality of tab connection holes to the second surface.

[0064] [Embodiment 3-1] A plurality of pouch-type battery cells arranged in a stack along a first direction; an internal housing that houses the plurality of pouch-type battery cells and has an internal air intake and an internal air exhaust; a housing containing the inner housing and having an intake port and an exhaust port; Equipped with the internal air intake port is located in a second direction perpendicular to the first direction relative to the internal air exhaust port; The intake port is located in the second direction relative to the exhaust port. Battery pack. [Embodiment 3-2] The battery pack of embodiment 3-1, wherein the internal exhaust port is substantially airtightly connected to the exhaust port or disposed within the exhaust port. [Embodiment 3-3] The battery pack according to embodiment 3-2, wherein the internal exhaust port and the exhaust port are located in an opposite direction to the second direction from the plurality of pouch-type battery cells. [Embodiment 3-4] The battery pack according to embodiment 3-2 or 3, wherein the air intake is located in the second direction further than the internal air intake. [Embodiment 3-5] A battery pack according to embodiment 3-4, wherein the air intake is located in the second direction relative to the plurality of pouch-type battery cells. [Embodiments 3-6] the inner housing has an inner side wall that faces the plurality of pouch-type battery cells in a third direction perpendicular to the first direction and the second direction; The battery pack according to any one of embodiments 3-2 to 5, wherein the internal air intake is provided in the internal side wall. [Embodiment 3-7] The internal air intake includes a plurality of through holes provided in the internal side wall, A battery pack according to any one of embodiments 3-6, wherein the plurality of through holes are arranged along the first direction, and each through hole is an elongated hole extending along the second direction. [Embodiment 3-8] At least one of the inner side wall of the inner housing and a side wall of the housing opposed to the inner side wall is provided with a flow guide wall protruding toward the other of them, The battery pack according to any one of embodiments 3 to 6 and 7, wherein the internal air intake is located in the second direction relative to the flow guide wall. [Embodiment 3-9] the inner housing includes a cell holder that holds the plurality of pouch-type battery cells and at least one substrate attached to the cell holder; The battery pack of any one of embodiments 3-1 to 8, wherein the at least one substrate has a circuit electrically connected to the plurality of pouch-type battery cells. [Embodiment 3-10] The at least one substrate includes a main substrate, A battery pack as described in embodiments 3-9, wherein the main board is positioned in the first direction relative to the plurality of pouch-type battery cells and has a power port for electrically connecting to an external device. [Embodiment 3-11] The at least one substrate includes a sub-substrate, A battery pack as described in embodiment 3-9 or 10, wherein the sub-substrate is positioned in the second direction relative to the plurality of pouch-type battery cells and is connected to the positive electrode tabs and the negative electrode tabs of each of the plurality of pouch-type battery cells. [Embodiment 3-12] A battery pack as described in any one of embodiments 3-11, wherein the air intake is located in the second direction further than the sub-board. [Embodiment 3-13] A battery pack as described in embodiment 3-1, wherein the internal air intake is substantially airtightly connected to the air intake or disposed within the air intake. [Embodiment 3-14] A battery pack as described in embodiment 3-14, wherein the internal air intake port and the air intake port are located in the second direction further from the plurality of pouch-type battery cells. [Embodiment 3-15] The battery pack according to any one of embodiments 3 to 13 and 14, wherein the exhaust port is located in the second direction relative to the internal exhaust port. [Embodiment 3-16] A battery pack according to any one of embodiments 3-15, wherein the exhaust port is located in a direction opposite to the second direction from the plurality of pouch-type battery cells. [Embodiment 3-17] the inner housing has an inner side wall that faces the plurality of pouch-type battery cells in a third direction perpendicular to the first direction and the second direction; 17. The battery pack of any one of embodiments 3-13 to 16, wherein the internal exhaust vent is provided in the internal side wall. [Embodiment 3-18] the internal exhaust port has a plurality of through holes provided in the internal side wall, A battery pack as described in embodiment 3-17, wherein the plurality of through holes are arranged along the first direction, and each through hole is an elongated hole extending along the second direction. [Embodiment 3-19] The battery pack according to any one of embodiments 3-1 to 18, wherein at least one of the intake port and the exhaust port is connected to a blower provided in an external device. [Explanation of symbols]

[0065] 10: Battery pack 12: Housing 14: Air intake 16: Exhaust port 26: Power port 28: Cushioning material 30: Cell unit 32: Internal housing 34: Internal air intake 36: Internal exhaust vent 38: Flow guide wall 40: Cell holder 50: Frame 54: Frame rib 55: Frame protrusion 56: Frame surface of the frame 58: Rim part of frame 60: Main board 70, 170: Sub-board 72: First conductor line 74: Second conductor line 76: 3rd conductor line 78: Tab connection hole 80: Connection parts 80x: Positive electrode lead plate 80y: Negative electrode lead plate 90: Encapsulating material 92: Glue

Claims

1. a plurality of pouch-type battery cells arranged in a stack along a first direction, each of the pouch-type battery cells having a positive electrode tab and a negative electrode tab protruding in a second direction perpendicular to the first direction; a substrate disposed in the second direction relative to the plurality of pouch-type battery cells, and to which the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells are connected; a frame to which the substrate is attached and which surrounds the plurality of pouch-type battery cells along the substrate; a sealant that fills an area surrounded by the frame and that encapsulates the positive electrode tabs and the negative electrode tabs that extend from the plurality of pouch-type battery cells to the substrate; a housing that accommodates the plurality of pouch-type battery cells, the substrate, and the frame; A battery pack comprising:

2. The battery pack according to claim 1 , wherein the sealing material is a potting material or a photocurable material.

3. The battery pack according to claim 1 , wherein the frame has a frame surface that contacts the substrate and is provided along a periphery of the substrate.

4. The battery pack according to claim 1 , wherein a sheet material that is softer than the frame and the substrate is interposed between the frame surface of the frame and the substrate.

5. the frame has an inner surface facing the plurality of pouch-type battery cells, The battery pack according to claim 1 , wherein the inner surface of the frame is provided with a plurality of ribs that respectively support the plurality of pouch-type battery cells.

6. The battery pack of claim 5 , wherein each of the plurality of ribs is located away from the substrate.

7. The battery pack according to claim 5 or 6, wherein each of the plurality of ribs has a notch located inside the sealing material.

8. the frame has a protrusion between each two adjacent ones of the plurality of ribs; The battery pack according to claim 5 , wherein the protrusion supports a corresponding one of the plurality of pouch-type battery cells from the second direction.

9. the substrate has a plurality of tab connection holes; 9. The battery pack according to claim 1, wherein the positive electrode tab or the negative electrode tab of a corresponding one of the pouch-type battery cells is inserted into each of the tab connection holes.

10. the substrate has a first surface facing the plurality of pouch-type battery cells and a second surface located opposite the first surface; The battery pack according to claim 9 , wherein each of the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells is joined to the substrate on the second surface.

11. The battery pack of claim 10 , wherein on the second surface of the substrate, the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells are covered with an adhesive.

12. a cell holder positioned inside the housing and configured to hold the pouch-type battery cells; The battery pack of claim 1 , wherein the frame is attached to the cell holder.

13. A method for manufacturing a battery pack, comprising: preparing a semi-finished product including: a plurality of pouch-type battery cells that are stacked along a first direction and each have a positive electrode tab and a negative electrode tab that protrude in a second direction perpendicular to the first direction; a substrate that is arranged in the second direction relative to the plurality of pouch-type battery cells and to which the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells are connected; and a frame to which the substrate is attached and that surrounds the plurality of pouch-type battery cells along the substrate; placing the semi-finished product such that an area surrounded by the frame is located above the substrate, and filling the area surrounded by the frame with a fluid material; curing the material to form an encapsulant encapsulating the positive and negative tabs extending from the plurality of pouch-type battery cells to the substrate; housing the plurality of pouch-type battery cells, the substrate, and the frame together with the sealing body in a housing; A manufacturing method comprising:

14. 14. The manufacturing method according to claim 13, wherein the step of preparing the semi-finished product includes the step of inserting the positive electrode tab or the negative electrode tab of a corresponding one of the plurality of pouch-type battery cells into each of a plurality of tab connection holes provided in the substrate.

15. the substrate has a first surface facing the plurality of pouch-type battery cells and a second surface located opposite the first surface; 15. The manufacturing method according to claim 14, wherein the step of preparing a semi-finished product further includes a step of joining each of the positive electrode tabs and the negative electrode tabs of the plurality of pouch-type battery cells inserted into the plurality of tab connection holes to the second surface.

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