Storage battery pack and method for assembling storage battery pack

Abstract

The problem to be solved by the present invention is to provide a battery pack and a method for assembling the battery pack, which have few limitations during mass production and are used for forming a pressure discharge flow path when an explosion occurs in a battery cell so as to improve the safety of a battery. In order to solve the problem, the present invention provides a battery pack (100) in which a through-hole (801) into which a pressing member is inserted and which presses a plurality of battery cells (70) via an end plate (95) is formed in a side wall part of a housing case (80), the outer surface of the end plate (95) in contact with the pressing member has a convex part (951) facing the pressing member (601), and the battery pack (100) has a spacer (85), and a spacer (85) which is disposed between the end plate (95) of the laminated single body ASSY in a state in which the interior of the housing case (80) is pressurized by the pressurizing member and the housing case (80), and which is larger than a convex portion (951), which is a pressurized surface of the end plate (95), and smaller than the housing case (80).

Description

Technical Field

[0001] The present invention relates to a battery pack and an assembly method thereof. Background Art

[0002] Conventionally, a battery module formed by stacking a plurality of battery cells has been known (see Patent Document 1).

[0003] [Prior Art Documents]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-044183 Summary of the Invention

[0006] [Problems to be Solved by the Invention]

[0007] In the above battery module formed by stacking a plurality of battery cells, since a pressure discharge flow path is to be formed when an explosion occurs in the battery cell, there are limitations in mass production.

[0008] An object of the present invention is to provide a battery pack and an assembly method thereof with fewer limitations in mass production, for forming a pressure discharge flow path when an explosion occurs in the battery cell, so as to improve the safety of the battery.

[0009] [Technical Means for Solving the Problems]

[0010] In order to achieve the above object, the present invention provides a battery pack (for example, the "battery pack 100" described later), comprising: a stacked monomer assembly (Assembly, ASSY) composed of a plurality of stacked battery monomers (for example, the "battery monomer 70" described later); and a box-shaped housing case with an upper opening (for example, the "housing case 80" described later); and the battery pack is formed by housing the aforementioned stacked monomer ASSY in the aforementioned housing case, and on the outer surface of the aforementioned stacked monomer ASSY in the stacking direction of the aforementioned plurality of battery monomers, there is an end plate (for example, the "end plate 95" described later), and in the side wall portion of the aforementioned housing case, there is formed a perforation (for example, the "perforation 801" described later) for inserting a pressing member (for example, the "spacer 85, pressing jig 601" described later) to press the aforementioned plurality of battery monomers via the aforementioned end plate, and the outer surface of the aforementioned end plate in contact with the aforementioned pressing member has a convex-shaped portion (for example, the "convex-shaped portion 951" described later) facing the aforementioned pressing member, and the battery pack has a spacer (for example, the "spacer 85" described later), and the spacer is disposed between the aforementioned end plate of the aforementioned stacked monomer ASSY in a state of being pressed by the aforementioned pressing member in the aforementioned housing case and the aforementioned housing case, larger than the pressing surface of the aforementioned end plate, that is, the aforementioned convex-shaped portion, and smaller than the aforementioned housing case.

[0011] In addition, the present invention provides a method for assembling a battery pack, the battery pack being formed by housing a stacked monomer ASSY composed of a plurality of stacked battery monomers (for example, the "battery monomer 70" described later) and an end plate (for example, the "end plate 95" described later) provided on the outer surface in the stacking direction of the aforementioned stacked monomer ASSY in a box-shaped housing case with an upper opening (for example, the "housing case 80" described later), and the method for assembling the battery pack has the following steps: a step of temporarily disposing a sandwiching member (for example, the "sandwiching member 602" described later) between a monomer ASSY housing (for example, the "constraint member 90" described later) that houses the plurality of battery monomers stacked in the aforementioned stacked monomer ASSY and the aforementioned housing case in a state where the aforementioned stacked monomer ASSY is pressed by a pressing member (for example, the "pressing jig 601" described later) in the aforementioned housing case; a step of forming a state where the aforementioned pressing is released and disposing a spacer between the aforementioned end plate and the aforementioned housing case; a step of pressing the aforementioned stacked monomer ASSY including the aforementioned spacer and pulling out the temporarily disposed aforementioned sandwiching member; and a step of retracting the aforementioned pressing member from the aforementioned housing case to fix the aforementioned spacer (for example, the "spacer 85" described later).

[0012] In the above invention, preferably, the aforementioned pressing member is composed of a square bar or a round bar independently provided on the left and right.

[0013] (Effects of the Invention)

[0014] According to the present invention, a battery pack with fewer restrictions during mass production and an assembly method of the battery pack can be provided, which are used to form a pressure discharge flow path when an explosion occurs in a battery cell, so as to improve the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a perspective view of the battery pack in the present embodiment.

[0016] Figure 2 is a plan view of the battery pack in the present embodiment.

[0017] Figure 3 is a sectional view along the Figure 2 A-A line of

[0018] Figure 4 is a plan view of an end portion in the stacking direction of the battery stack of the battery pack in the present embodiment.

[0019] Figure 5 is an enlarged perspective view of an end portion in the stacking direction of the battery stack of the battery pack in the present embodiment.

[0020] Figure 6 is an enlarged partial sectional view of an end portion in the stacking direction of the battery stack of the battery pack in the present embodiment.

[0021] Figure 7 is a view showing the positional relationship between a spacer and an end plate at an end portion in the stacking direction of the battery stack of the battery pack in the present embodiment.

[0022] Figure 8 is an exploded perspective view of the battery pack in the present embodiment.

[0023] Figure 9 is a perspective view of the battery module of the battery pack in the present embodiment.

[0024] Figure 10 is a view showing a situation where an upper part and a lower part are assembled to the battery stack from the upper side and the lower side of the battery module in the present embodiment.

[0025] Figure 11 is a side view of the battery module in the present embodiment.

[0026] Figure 12 is along Figure 11 a sectional perspective view along the B-B line of

[0027] Figure 13 is along Figure 11Stereoscopic sectional view of the C-C line.

[0028] Figure 14 Is an enlarged stereoscopic view of the battery module in the present embodiment.

[0029] Figure 15 Is a stereoscopic view showing the state of the battery module in the present embodiment before being inserted into the housing.

[0030] Figure 16 Is a sectional view showing the situation of inserting the battery module in the present embodiment into the housing.

[0031] Figure 17 Is a plan view of the end of the battery module showing the situation of inserting the battery module in the present embodiment into the housing.

[0032] Figure 18 Is a sectional view showing the situation of pressing the end plate from the perforation with a pressing jig in the state where the battery module in the present embodiment is inserted into the housing.

[0033] Figure 19 Is a plan view of the end of the battery module showing the situation of pressing the end plate from the perforation with a pressing jig in the state where the battery module in the present embodiment is inserted into the housing.

[0034] Figure 20 Is a sectional view showing the situation where a clamping jig is inserted in the state where the battery module in the present embodiment inserted into the housing has been pressed with a pressing jig.

[0035] Figure 21 Is a plan view of the end of the battery module showing the situation where a clamping jig is inserted in the state where the battery module in the present embodiment inserted into the housing has been pressed with a pressing jig.

[0036] Figure 22 Is a sectional view showing the situation where the pressing jig for pressing the battery module is retracted after inserting a spacer into the battery module in the present embodiment inserted into the housing.

[0037] Figure 23 Is a plan view of the end of the battery module showing the situation where the pressing jig for pressing the battery module is retracted after inserting a spacer into the battery module in the present embodiment inserted into the housing.

[0038] Figure 24 Is a sectional view showing the situation of pressing the battery module in the present embodiment inserted into the housing and pulling out the clamping jig.

[0039] Figure 25It is a plan view of the end portion of the battery module showing the case where the battery module in this embodiment inserted into the housing is pressurized and the clamping jig is pulled out.

[0040] Figure 26 It is a sectional view showing the case where the pressing jig is retracted from the battery module in this embodiment inserted into the housing.

[0041] Figure 27 It is a plan view of the end portion of the battery module showing the case where the pressing jig is retracted from the battery module in this embodiment inserted into the housing. Detailed Embodiment

[0042] Hereinafter, embodiments of the present invention will be described. As Figure 1 shown, for example, the battery pack 100 includes a restraint member 90, a housing 80, two battery laminates Bs, a flow path member 60, a single-cell pressing plate 30, and a lid 20.

[0043] Hereinafter, as Figure 2 shown, for example, two specified directions orthogonal to each other in the horizontal plane are referred to as the "X direction" and the "Y direction". In addition, one of the X directions is referred to as the "X− direction", and the opposite direction is referred to as the "X+ direction". In addition, one of the Y directions is referred to as the "Y− direction", and the opposite direction is referred to as the "Y+ direction".

[0044] As Figure 1 , Figure 2 shown, for example, the housing 80 has a box shape that is open upward, and houses two battery laminates Bs side by side in the X direction. The material of the housing 80 is metal or the like.

[0045] On the outer surface of the front wall of the housing 80 (the surface opposite to the battery laminate Bs side), as Figure 6 shown, a perforation 801 is formed, and the perforation 801 is used for inserting a pressing jig 601 (see Figure 18 etc.) constituted by a pressing rod to pressurize the battery laminate Bs via an end plate 95. At a position facing the perforation 801, a spacer 85 serving as a pressurizing member is provided, and the pressurizing member contacts a relatively thick convex portion of the end plate 95 described later to pressurize the battery laminate Bs.

[0046] At the position of the spacer 85 facing the perforation 801, a disk-shaped concave portion 851 that is recessed toward the battery laminate Bs side is formed. A pressure release valve (not shown) is provided in the perforation 801.

[0047] As Figure 2As shown in the figure, each battery laminate Bs includes a plurality of battery cells 70 and a plurality of separators 79. Each battery laminate Bs is formed in a state constrained by a constraining member 90, and constitutes a battery module 200. By disposing end plates 95 (refer to Figure 3 etc.) at the ends in the stacking direction of the battery module 200, a stacked cell ASSY (stacked cell assembly) is constituted.

[0048] Each battery cell 70 has a rectangular outer package that is elongated in the Y direction. Therefore, the "Y direction" can also be alternatively referred to as the "cell longitudinal direction". In each battery laminate Bs, the battery cells 70 are stacked in the X direction. Therefore, the "X direction" can also be alternatively referred to as the "stacking direction". The separator 79 is a plate-shaped member that extends in the Y direction and the up and down directions, and is disposed between two battery cells 70 juxtaposed in the X direction. The material of the separator 79 is resin or the like.

[0049] Between the battery laminate Bs on the Y− direction side and the housing 80, between two battery laminates Bs, and between the battery laminate Bs on the Y+ direction side and the housing 80, plate-shaped spacers 89 that extend in the X direction and the up and down directions are provided. The material of the spacers 89 is resin or the like.

[0050] Each battery cell 70 has a positive electrode p (refer to Figure 2 、 Figure 14 etc.) at one end in the Y direction on the upper surface of the outer package, and a negative electrode n (refer to Figure 14 etc.) at the other end in the Y direction on the upper surface of the outer package. Specifically, for a specified plurality of battery cells 70, the positive electrode p is disposed on the Y− direction side, and the negative electrode n is disposed on the Y+ direction side. On the other hand, for the other battery cells 70, the negative electrode n is disposed on the Y− direction side, and the positive electrode p is disposed on the Y+ direction side.

[0051] The electrodes p and n of the battery cells 70 adjacent to each other in the Y direction or the X direction are electrically connected by a conductive member (not shown). On the other hand, the positive electrode p of the battery cell 70 on the most positive side electrically is connected to the positive electrode P of the entire battery pack 100 by a conductive member (not shown). In addition, the negative electrode n of the battery cell 70 on the most negative side electrically is connected to the negative electrode N of the entire battery pack 100 by another conductive member (not shown). Based on the above, in the present embodiment, all the battery cells 70 in the battery pack 100 are connected in series.

[0052] As Figure 2As shown in the figure, each battery cell 70 has a safety valve 76 at the central part of the upper surface of the outer package, which can discharge the gas inside the battery cell 70. Specifically, the part of the upper surface of the outer package of each battery cell 70 that constitutes the safety valve 76 is configured to be weaker than other parts. Therefore, when the pressure inside the battery cell 70 rises, that is, when the pressure inside the outer package rises, the part of the outer package that constitutes the safety valve 76 is damaged first, and the pressure is released from here.

[0053] The flow channel member 60 is an insulating member such as resin, and is provided for each battery stack Bs. Each flow channel member 60 is provided on the upper surface of the corresponding battery stack Bs.

[0054] As Figure 2 , Figure 8 and so on, the single cell pressing plate 30 is an elongated plate-shaped member extending in the X direction, and is arranged parallel to the X direction at the central position and both ends in the Y direction on the upper surface of a pair of battery stacks Bs in the battery pack 100. The single cell pressing plate 30 sandwiches the upper part 92 of the restraining member 90 described later together with the cover 20 from above, thereby absorbing the unevenness in the height of the battery cells 70.

[0055] The material of the single cell pressing plate 30 is metal or the like. A flow channel forming portion (not shown) for the refrigerant to flow through is formed in the portion of the single cell pressing plate 30 located above the flow channel member 60. The cover 20, as Figure 8 and so on, is formed in a rectangular plate shape and covers the single cell pressing plate 30 from above. The material of the cover 20 is metal or the like. The cover 20 constitutes a water jacket for allowing the refrigerant to flow through the flow channel member 60.

[0056] The stacked single cell ASSY formed by arranging end plates 95 at both ends in the stacking direction (lateral direction as the horizontal direction) of the battery module 200 includes a battery stack Bs, a restraining member 90, and an end plate 95. The restraining member 90, as Figure 10 and so on, has a lower part 91 and an upper part 92. By means of the restraining member 90, the pressurized state of the battery cells 70 in the battery stack Bs is maintained. The lower part 91 has: a rectangular lower frame part 911 with an opening part 913 having a central opening; and side wall parts 912 standing up from a pair of long sides of the lower frame part 911; the lower part 91 restrains a plurality of battery cells 70 from the lower side of the battery stack Bs.

[0057] The lower frame part 911, as Figure 10 , Figure 11 , Figure 13As shown in the like, it constitutes a seamless ring-shaped frame surrounding the periphery of the lower end portion of the battery laminate Bs. With this configuration, the lower frame portion 911 is assembled and disposed so as to surround the periphery of the lower end portion of the battery laminate Bs. Thus, the lower frame portion 911 restricts the lower end portion of the battery laminate Bs in the stacking direction of the plurality of battery cells 70 in the battery laminate Bs.

[0058] The side wall portion 912 covers the vicinity of the upper end portion of the side surface portion from the lower end portion of the side surface portion of the battery laminate Bs in an opposing manner. At the upper end portion of the side wall portion 912, as Figure 15 shown in the like, a plurality of trapezoidal protrusions 916 project upward from the upper end edge of the side wall portion 912 and are located above the upper surface of the upper member 92. As Figure 14 shown in the like, the upper member 92 and the lower member 91 are joined at the side surface portion of the outer peripheral portion of the battery laminate Bs by fitting or bonding. By joining the upper member 92 and the lower member 91, the restraining member 90 has a shape in which the entire upper surface and the lower surface are open, and both end surfaces in the stacking direction of the battery laminate Bs are open. In addition, for the sake of convenience in explanation, in the Figure 15 figures other than the like, the protrusions 916 are omitted.

[0059] On the outer surface of the side wall portion 912, a plurality of trapezoidal convex portions 915 project in a direction away from the outer surface of the side wall portion 912. The convex portion 915 is configured to be pushed inward of the battery laminate Bs by the side wall portion 912 of the lower member 91 from the side, and thus is appropriately deformed. Thereby, it is configured to absorb the unevenness in the length in the cell longitudinal direction of the battery cell 70.

[0060] The upper member 92 has a rectangular upper frame portion 921, and the rectangular upper frame portion 921 has an opening portion 923 with a central opening; the upper member 92 restricts the plurality of battery cells 70 from above the battery laminate Bs. The upper frame portion 921, as Figure 10 、 Figure 12 shown in the like, constitutes a seamless ring-shaped frame surrounding the periphery of the upper end portion of the battery laminate Bs. With this configuration, the upper frame portion 921 is assembled and disposed so as to surround the periphery of the upper end portion of the battery laminate Bs. Thus, the upper frame portion 921 restricts the upper end portion of the battery laminate Bs in the stacking direction of the plurality of battery cells 70 in the battery laminate Bs.

[0061] On the upper surface of the long side of the upper member 92, as Figure 14 shown in the like, a plurality of trapezoidal convex portions 925 project upward. The convex portion 925 is configured to be pushed downward from above by the cell pressing plate 30 and the cover body 20, and thus is appropriately deformed. Thereby, the unevenness in the height of the battery cell 70 is absorbed.

[0062] The end plate 95 is assembled to the front surface in the stacking direction of the plurality of battery cells 70 assembled on the restraining member 90, that is, the end surface of the battery stack Bs in the same direction. Specifically, the end plate 95 is formed in a rectangular plate shape made of resin, as shown in, for example, Figure 16 etc., and is fixed between the lower frame portion 911 and the upper frame portion 921 of the upper member 92 and the lower member 91 (refer to Figure 10 etc.) and the battery stack Bs, and is also fixed between the front wall 813 of the housing 80 (refer to Figure 3 , Figure 6 etc.) and the battery stack Bs.

[0063] The peripheral portion of the end plate 95 is formed to be thinner. Therefore, the portion other than the peripheral portion has a convex-shaped portion 951 that is relatively thick compared to the peripheral portion, as shown in, for example, Figure 3 etc. In this relatively thick convex-shaped portion 951, the end surfaces of both ends of the restraining member 90 in the stacking direction of the battery stack Bs protrude from the opening along the stacking direction of the restraining member 90, as shown in, for example, Figure 3 etc. Thus, the convex-shaped portion 951 protrudes toward the spacer 85, which is a pressing member that presses the battery stack Bs, with respect to the restraining member 90. In addition, as shown in, for example, Figure 7 etc., in the vertical direction, the spacer 85 is larger in size than the end plate 95, and in the Y direction, the end plate 95 is larger in size than the spacer 85. Thus, the pressing surface of the spacer 85, that is, the convex-shaped portion 951, is larger than the end plate 95.

[0064] Next, the assembling method of the battery pack 100 having the above-described structure will be described. First, an overview (image) of the assembling method of the battery pack 100 will be described.

[0065] In the assembling method of the battery pack 100, first, as shown in, for example, Figure 9 etc., the battery module 200 in a state restrained by the restraining member 90 is assembled while the battery stack Bs is being pressed in the stacking direction of the battery cells 70 in the battery stack Bs. That is, as shown in, for example, Figure 9 , Figure 10 etc., for the upper member 92 and the lower member 91 that constitute the restraining member 90 (refer to Figure 3 etc.), the upper member 92 is assembled from above and the lower member 91 is assembled from below to the battery stack Bs in a state where it is pressed in the stacking direction of the battery cells 70. Then, the lower member 91 is suspended by being grasped by a grasping jig 507 (not shown) at the protrusion 916 (refer to Figure 15 etc.), inserted into the housing 80, and pushed into the housing 80 from above.

[0066] Regarding the specific assembly method of the battery pack 100, as follows. In the assembly method of the battery pack 100, first, using an assembly jig (not shown), assemble the battery module 200 as shown in Figures 11 to 15 . In the assembled battery module 200, on the outer surface of the end portion in the stacking direction of the battery stack Bs, the convex portion 951 of the end plate 95 is arranged in a state of protruding from the restraint member 90 as shown in Figure 3 、 Figure 16 .

[0067] Next, the process from assembling the battery module 200 to the housing 80 to completing the assembly of the battery pack 100 in the assembly method of the battery pack 100 will be described. First, for the battery module 200 provided with the end plate 95, hold the protrusion 916 (refer to Figure 15 ) of the held portion of the lower member 91 as the held portion by a holding jig (not shown), lift it up, insert it into the housing 80, and push it into the housing 80 from the upper side.

[0068] Then, as shown in Figure 18 、 Figure 19 , insert the pressing jig 601, which is a pressing member composed of a round bar or a square bar, into the perforation 801 of the housing 80. Then, bring the pressing jig 601 into contact with and abut against the relatively thick convex portion 951 of the end plate 95, press the end plate 95, thereby pressing the battery module 200 provided with the end plate 95 in the stacking direction of the battery cells 70, and forming a gap between the housing 80 and the end plate 95.

[0069] Next, as shown in Figure 20 、 Figure 21 , temporarily insert the clamping jig 602, which is a clamping member, into the formed gap. Thus, the clamping jig 602 is arranged so as to be located around the pressing jig 601. Next, as shown in Figure 22 、 Figure 23 , pull out the pressing jig 601 from the perforation 801. Thus, a state in which the pressing of the battery module 200 is released is formed. At this time, due to the presence of the clamping jig 602, the pressing of the battery module 200 is maintained. Then, insert the spacer 85 into the gap maintained by the clamping jig 602.

[0070] Next, as shown in Figure 24 、 Figure 25 , insert the pressing jig 601 into the perforation 801 of the housing 80, bring the pressing jig 601 into contact with and abut against the spacer 85, and press the spacer 85. Then, pull out the clamping jig 602. Next, as shown in Figure 26 、 Figure 27As shown, the pressing jig 601 is retracted from the perforation 801 and pulled out. Thus, the spacer 85 is fixed in a state of being clamped between the housing 80 and the end plate 95. The above process is the process from assembling the battery module 200 to the housing 80 to completing the assembly of the battery pack 100 in the assembly method of the battery pack 100.

[0071] The effects brought about by the above-described embodiment are as follows.

[0072] In the present embodiment, the restraining member 90 of the battery module 200 constituting the battery pack 100 is composed of an upper member 92 and a lower member 91. The upper member 92 is a frame member for restraining from the upper side of a plurality of battery cells 70 laminated horizontally, and the lower member 91 is a frame member for restraining from the lower side of a plurality of battery cells 70 laminated horizontally. The restraining member 90 restrains the plurality of battery cells 70 laminated in the stacking direction.

[0073] Thus, it is possible to fix in a state where the plurality of battery cells 70 are compressed and restrained by the restraining member 90 which is a frame. Therefore, it is possible to reduce the occupied volume of accessory parts other than the battery cells 70 in the Intelligent Power Unit (IPU), improve the monomer filling rate, and extend the cruising range in a Battery Electric Vehicle (BEV). In particular, since the upper member 92 and the lower member 91 are composed of seamless frames assembled on the plurality of battery cells 70 laminated, it is possible to be reliably restrained by the restraining member 90.

[0074] In addition, in the present embodiment, the upper member 92 and the lower member 91 of the battery module 200 are joined at the side faces of the outer peripheral portions of the plurality of battery cells 70 laminated by being embedded or bonded. Thus, the lower member 91 can be made into a structure that is more located outside than the upper member 92 and joined to the upper member 92. Therefore, the lower member 91 can be used for purposes other than the restraint of the restraining member 90. For example, a structure having a protrusion 916 at the upper end of the lower member 91 can be made, and the battery module 200 can be carried by grasping the protrusion 916. In addition, the number of parts can be reduced by the upper and lower integration of the restraining member 90, thereby enabling cost reduction.

[0075] In the present embodiment, the upper member 92 is configured to cover the upper ends of a plurality of laterally stacked battery cells 70 and is open with respect to the upper surfaces of the plurality of laterally stacked battery cells 70. Further, the lower member 91 is configured to cover the lower ends of the plurality of laterally stacked battery cells and is open with respect to the lower surfaces of the plurality of laterally stacked battery cells. Further, the end portions of the constraining member 90 that constrains the stacked plurality of battery cells 70 in the stacking direction are open.

[0076] Thereby, a frame structure can be formed that covers and constrains the upper and lower ends of the entire battery stack Bs having the battery cells 70, so that when the reaction force caused by the compression of the battery cells 70 decreases, the movement of the constraining member 90 relative to the battery cells 70 of the battery stack Bs can be suppressed.

[0077] Further, in the present embodiment, in the step of pressurizing the battery stack Bs, the stacked plurality of battery cells 70 are pressurized from one side or both sides in the stacking direction. Thereby, the battery stack Bs can be appropriately pressurized from one side or both sides.

[0078] Further, in the present embodiment, in the battery pack 100, an end plate 95 is provided on the outer surface of the stacked unit ASSY in the stacking direction of the plurality of battery cells 70, and the outer surface of the end plate 95 is in contact with a pressing jig 601 that is a pressing member and presses the stacked unit ASSY housed in the housing 80. The outer surface of the end plate 95 in contact with the pressing jig 601 has a convex-shaped portion 951 that is a convex-shaped portion facing the pressing jig 601.

[0079] Thereby, by pressing the convex-shaped portion 951, a compressive load generated by the pressing is applied to the entire surface of the end plate 95 on the side opposite to the convex-shaped portion 951 side in the stacking direction of the battery cells 70 of the battery stack Bs. Therefore, the stacked unit ASSY can be uniformly pressed by being pressurized integrally with the end plate 95. Further, when the stacked unit ASSY is uniformly pressed by pressurizing the convex-shaped portion 951 of the end plate 95, a limited range in the center of the battery cells 70 can be pressurized, and as described above, the stacked unit ASSY can be uniformly pressed. Further, since the convex-shaped portion 951 can be pressurized before being assembled to the housing 80 to compress the plurality of battery cells 70, the restrictions during mass production can be reduced.

[0080] In addition, in the present embodiment, the end plate 95 is assembled to the end surface in the stacking direction of the plurality of battery cells 70 assembled to the restraint member 90. Further, the end plate 95 is fixed between the upper frame portion 921 and the lower frame portion 911, which are the frame portions of the upper member 92 and the lower member 91, and the battery cell 70. Further, a portion 951, which is a convex-shaped portion of the end plate 95, protrudes toward the pusher jig 601, which is a pressing jig, with respect to the restraint member 90.

[0081] Thereby, by pressing the portion 951, which is a convex-shaped portion, toward the battery cell 70, the battery cells 70 of the battery stack Bs can be pressed comprehensively and evenly on the side of the end plate 95 opposite to the portion 951, which is a convex-shaped portion.

[0082] In addition, in the present embodiment, a perforation 801 is formed in the front wall 813 among the wall portions of the housing 80, which is a housing case, for inserting the pusher jig 601, which is a pressing jig, to press the plurality of battery cells 70 via the end plate 95. Thereby, the pusher jig 601 can be inserted through the perforation 801 to press the portion 951, which is a convex-shaped portion of the end plate 95, with the pusher jig 601.

[0083] In addition, in the present embodiment, a spacer 85 is disposed between the end plate 95 of the plurality of battery cells 70 in a pressurized state and the housing 80, which is a housing case. Thereby, after the portion 951, which is a convex-shaped portion of the end plate 95, is pressed with the pusher jig 601 and the pusher jig 601 is removed, the pressurized state of the battery cells 70 can be maintained.

[0084] In addition, in the present embodiment, the storage battery pack 100 has a spacer 85 that is disposed between the end plate 95 of the stacked unit ASSY, which has been pressed by the pusher jig 60, which is a pressing member, in the housing 80, and the housing 80, and is larger than the pressing surface of the end plate 95, that is, the portion 951, which is a convex-shaped portion, and smaller than the housing 80.

[0085] Thereby, by disposing the spacer 85 and the end plate 95 in the housing 80, uneven pressurization of the battery stack Bs in the stacking direction of the battery cells 70 in the housing 80 can be suppressed. Further, since the spacer 85 is smaller than the housing 80, a gap 83 can be formed in the width direction of the housing 80. As a result, when the battery cell 70 explodes, the pressure can be released to this gap.

[0086] In the present embodiment, in the method of assembling the battery pack 100, the following steps are included: a step of temporarily disposing a sandwiching jig 602 as a sandwiching member between a restraint member 90, which is a monomer ASSY housing (monomer assembly housing) that houses a plurality of battery monomers 70 laminated in the laminated monomer ASSY, and a housing 80, with the laminated monomer ASSY being in a state of being pressed by a pressing jig 601 as a pressing member within the housing 80; a step of forming a state where the pressure is released and disposing a spacer 85 between an end plate 95 and the housing 80; a step of pressing the laminated monomer ASSY including the spacer and pulling out the temporarily disposed sandwiching jig 602; and a step of retracting the pressing jig 601 from the housing 80 and fixing the spacer 85.

[0087] Thereby, the spacer 85 for maintaining the laminated monomer ASSY in a pressed state can be assembled to the battery pack. As a result, fixation can be performed in a state where the plurality of battery monomers 70 are compressed and constrained by the restraint member 90 as a frame. Therefore, it is possible to reduce the occupied volume of accessory parts other than the battery monomers 70 in the Intelligent Power Unit (IPU), thereby improving the monomer filling rate and extending the cruising range in a Battery Electric Vehicle (BEV).

[0088] Furthermore, the present invention is not limited to the above-described embodiment, and variations, improvements, etc. within the scope where the object of the present invention can be achieved are included in the present invention.

[0089] For example, in the above-described embodiment, the pressing jig 601 presses the battery monomers 70 of the battery laminate Bs constituting the laminated monomer ASSY from one of the lamination directions thereof, but is not limited thereto. For example, the pressing jig may be formed of a round bar or a square bar, and one or a pair may be provided respectively, and the battery monomers of the battery laminate may be pressed from one or both of the lamination directions thereof. In addition, the restraint member may be configured to have a member that forms a pair of one end side and the other end side in a direction other than the up-down direction, for example, the left-right direction, instead of the lower member 91 and the upper member 92.

[0090] Reference Numerals

[0091] 70 Battery monomer

[0092] 80 Housing (accommodating housing)

[0093] 85 Spacer

[0094] 90 Restraint member (monomer ASSY housing)

[0095] 91 Lower part (the other end side part)

[0096] 92 Upper part (one end side part)

[0097] 95 End plate

[0098] 100 Battery pack

[0099] 200 Battery module

[0100] 601 Pressing jig (pressing part, round bar)

[0101] 602 Clamping jig

[0102] 801 Perforation

[0103] 913, 923 Opening

[0104] 916 Protrusion (part to be gripped)

[0105] 951 Convex-shaped part (convex-shaped portion)

Claims

1. A battery pack, comprising: a stacked cell assembly composed of a plurality of stacked battery cells; and a box-shaped housing with an upper opening; and the battery pack is formed by housing the aforementioned stacked cell assembly in the aforementioned housing, and an end plate is provided on the outer surface of the aforementioned stacked cell assembly in the stacking direction of the aforementioned plurality of battery cells, a perforation is formed in the side wall portion of the aforementioned housing for inserting a pressing member to press the aforementioned plurality of battery cells via the aforementioned end plate, the outer surface of the aforementioned end plate in contact with the aforementioned pressing member has a convex-shaped portion facing the aforementioned pressing member, and the battery pack has a spacer, and the spacer is disposed between the aforementioned end plate of the aforementioned stacked cell assembly in a state where the aforementioned stacked cell assembly is pressed by the aforementioned pressing member in the aforementioned housing and the aforementioned housing, and is larger than the pressing surface of the aforementioned end plate, that is, the aforementioned convex-shaped portion, and smaller than the aforementioned housing.

2. An assembling method of a battery pack, the battery pack being formed by housing a stacked cell assembly composed of a plurality of stacked battery cells and an end plate provided on the outer surface in the stacking direction of the aforementioned stacked cell assembly in a box-shaped housing with an upper opening, the assembling method of the battery pack having the following steps: a step of temporarily providing a sandwiching member between a cell assembly housing that houses the plurality of stacked battery cells in the aforementioned stacked cell assembly and the aforementioned housing in a state where the aforementioned stacked cell assembly is pressed by a pressing member in the aforementioned housing; a step of forming a state where the aforementioned pressing is released and providing a spacer between the aforementioned end plate and the aforementioned housing; a step of pressing the aforementioned stacked cell assembly including the aforementioned spacer and pulling out the temporarily provided aforementioned sandwiching member; and a step of retracting the aforementioned pressing member from the aforementioned housing to fix the aforementioned spacer.

3. The assembling method of a battery pack according to claim 2, wherein the aforementioned pressing member is composed of a square bar or a round bar independently provided on the left and right.

Images