Battery module and method for assembling battery module

Abstract

The problem to be solved by the present invention is to provide a battery module having a small number of components and capable of improving the energy efficiency of a battery by reducing the volume occupied by accessory components other than battery cells. In order to solve the problem, in a battery module 200 of the present invention, one end side member of a restraining member 90 is a frame member for restraining from the upper side of a plurality of battery cells 70 stacked in the lateral direction, and the other end side member is a frame member for restraining from the lower side of a plurality of battery cells 70 stacked in the lateral direction. The one-end-side member and the other-end-side member are joined at the outer peripheral portions of the plurality of stacked battery cells, and the restraining member 90 restrains the plurality of stacked battery cells 70 in the stacking direction.

Description

Technical Field

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

[0002] Conventionally, there have been known power storage modules formed by stacking a plurality of battery cells (see Patent Documents 1 to 4).

[0003] [Prior Art Documents]

[0004] (Patent Documents)

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2023-055487

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2021-009786

[0007] Patent Document 3: Japanese Patent Application Laid-Open No. 2022-055798

[0008] Patent Document 4: Japanese Patent Application Laid-Open No. 2023-060672 Summary of the Invention

[0009] [Problems to be Solved by the Invention]

[0010] In the above-mentioned power storage module or the like, the number of parts of the restraining member for restraining a plurality of battery cells is large, and thus it is required to reduce the number of parts and the occupied volume of accessory parts other than the battery cells.

[0011] An object of the present invention is to provide a battery module having a small number of parts and capable of reducing the occupied volume of accessory parts other than the battery cells, thereby improving the energy efficiency of the battery.

[0012] [Technical Means for Solving the Problems]

[0013] To achieve the above object, the present invention provides a battery module (e.g., the following "battery module 200"), comprising: a plurality of stacked battery cells (e.g., the following "battery cell 70"); and a restraining member (e.g., the following "restraining member 90") that restrains the stacked plurality of battery cells in the stacking direction thereof; and the restraining member is composed of a one-end-side member (e.g., the following "upper member 92") and a the other-end-side member (e.g., the following "lower member 91") to restrain the plurality of battery cells, the one-end-side member is a frame member for restraining from the upper side of the stacked plurality of battery cells in the lateral direction, the other-end-side member is a frame member for restraining from the lower side of the stacked plurality of battery cells in the lateral direction, the one-end-side member and the other-end-side member are joined at the outer peripheral portion of the stacked plurality of battery cells, and the restraining member restrains the stacked plurality of battery cells in the stacking direction.

[0014] In the above invention, it is preferable that the stacked plurality of battery cells are in a pressurized state. In addition, it is preferable that the one-end-side member and the other-end-side member are joined at the side surface portion of the outer peripheral portion of the stacked plurality of battery cells. It is preferable that the other-end-side member is located more outside than the one-end-side member and is joined to the one-end-side member.

[0015] In addition, it is preferable that the one-end-side member and the other-end-side member are joined by embedding or adhesion. It is preferable that the one-end-side member is configured to cover the upper end portions of the stacked plurality of battery cells in the lateral direction and is open with respect to the upper surface of the stacked plurality of battery cells in the lateral direction, and the other-end-side member is configured to cover the lower end portions of the stacked plurality of battery cells in the lateral direction and is open with respect to the lower surface of the stacked plurality of battery cells in the lateral direction.

[0016] In addition, it is preferable that the end portion of the restraining member that restrains the stacked plurality of battery cells in the stacking direction is open. It is preferable that the other-end-side member is configured to cover from the lower end portion to the side surface portion of the stacked plurality of battery cells in the lateral direction, and the upper end portion of the other-end-side member is located more above than the upper surface of the one-end-side member. It is preferable that the upper end portion of the other-end-side member has a protrusion portion (e.g., the following "protrusion portion 916") that is located more above than the upper surface of the one-end-side member.

[0017] In addition, the present invention provides an assembling method for a battery module, which is an assembling method of installing a restraining member (for example, the following "restraining member 90") on a plurality of stacked battery cells (for example, the following "battery cell 70"). The restraining member is composed of a one-end-side member (for example, the following "upper member 92") and a the other-end-side member (for example, the following "lower member 91"). The assembling method of the battery module includes the following steps: arranging the plurality of battery cells in a stacked state on an assembling jig (for example, the following "assembling jig 500"); using a pressing device (for example, the following "pressing jig 505") to press the plurality of battery cells that have been arranged in the stacking direction; when the plurality of battery cells are compressed to a specific distance by pressing, embedding the other-end-side member in such a way as to cover the plurality of stacked battery cells in the lateral direction from below; embedding the one-end-side member that covers the upper surface of the battery cells from the upper surface of the plurality of stacked battery cells in the lateral direction that have been pressed; and joining the one-end-side member and the other-end-side member that are embedded above and below the battery cells.

[0018] In the above invention, it is preferable that the lower side portion of the assembling jig has an upward pushing jig (for example, the following "upward pushing jig 503") including a push pin (for example, the following "upper push pin 504") and a groove portion (for example, the following "groove 5031"). In the step of embedding the other-end-side member, the other-end-side member is arranged in the groove portion, and the upward pushing jig including the push pin is used to upwardly push the other-end-side member, so as to embed the plurality of stacked battery cells into the other-end-side member.

[0019] In addition, it is preferable that in the pressing step, the plurality of stacked battery cells are pressed from one side or both sides in the stacking direction.

[0020] In addition, it is preferable that in the step of embedding the one-end-side member, the one-end-side member is embedded from the upper side of the plurality of stacked battery cells after the other-end-side member is embedded below, or from the upper side of the plurality of stacked battery cells before the other-end-side member is embedded below. In addition, it is preferable that in the step of joining the one-end-side member and the other-end-side member, the one-end-side member and the other-end-side member are joined by fitting or welding. In addition, it is preferable that the one-end-side member and the other-end-side member respectively form a frame body, the frame body has an annular shape and fixes the plurality of battery cells. In addition, it is preferable that the other-end-side member has a grasped portion (for example, the following "protrusion 916"), which can be grasped when the plurality of stacked battery cells with the restraining member installed are received in the housing of the battery module.

[0021] (Effect of the invention)

[0022] According to the present invention, a battery module can be provided. The battery module has a small number of parts and can reduce the occupied volume of accessory parts other than battery cells, thereby improving the energy efficiency of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 FIG. is a perspective view showing a battery pack in the present embodiment.

[0024] Figure 2 FIG. is a top view showing a battery pack in the present embodiment.

[0025] Figure 3 is a sectional view along Figure 2 line A-A of

[0026] Figure 4 FIG. is a top view of an end portion in the stacking direction of a battery stack of a battery pack in the present embodiment.

[0027] Figure 5 FIG. is an enlarged perspective view of an end portion in the stacking direction of a battery stack of a battery pack in the present embodiment.

[0028] Figure 6 FIG. is a partially enlarged sectional view of an end portion in the stacking direction of a battery stack of a battery pack in the present embodiment.

[0029] Figure 7 FIG. is an exploded perspective view showing a battery pack in the present embodiment.

[0030] Figure 8 FIG. is a perspective view showing a battery module of a battery pack in the present embodiment.

[0031] Figure 9 FIG. is a view showing a state in which an upper member and a lower member are inserted into a battery module of the present embodiment from above and below the battery stack.

[0032] Figure 10 FIG. is a side view showing a battery module of the present embodiment.

[0033] Figure 11 is along Figure 10 line B-B of

[0034] Figure 12 is along Figure 10 line C-C of

[0035] Figure 13 FIG. is an enlarged perspective view showing a battery module of the present embodiment.

[0036] Figure 14 FIG. is a perspective view showing a state before a battery module of the present embodiment is inserted into a housing.

[0037] Figure 15 is a perspective view of an assembly jig for a battery laminate of a battery module in which a restraint member is embedded in the present embodiment.

[0038] Figure 16 is a view for explaining a case where a restraint member is embedded in a battery laminate of a battery module in the present embodiment in the assembly jig.

[0039] Figure 17 is a side sectional view showing a case where a lower member of a restraint member is embedded in a battery laminate of a battery module in the present embodiment.

[0040] Figure 18 is along Figure 17 sectional view taken along line D-D.

[0041] Figure 19 is a view for explaining a case where a lower member and an upper member of a restraint member are embedded in a pressurized battery laminate of a battery module in the present embodiment.

[0042] Figure 20 is a view for explaining a case where a restraint member is embedded in a battery laminate of the present embodiment.

[0043] Figure 21 is a view for explaining a case where a battery module in the present embodiment is inserted into a housing.

[0044] Figure 22 is a view for explaining a case where a battery module in the present embodiment is inserted into a housing.

[0045] Figure 23 is a perspective view showing a case where a lower member of a restraint member of a battery module in the present embodiment is inserted into a groove formed on the upper surface of a pusher jig.

[0046] Figure 24 is a perspective view showing a case where a battery laminate is disposed on a lower member of a restraint member of a battery module in the present embodiment inserted into a groove formed on the upper surface of a pusher jig.

[0047] Figure 25 is a perspective view showing a case after a battery laminate is disposed on a lower member of a restraint member of a battery module in the present embodiment inserted into a groove formed on the upper surface of a pusher jig.

[0048] Figure 26 is a perspective view showing a case where a battery laminate disposed on a lower member of a restraint member of a battery module in the present embodiment is pressurized in the stacking direction of battery cells.

[0049] Figure 27It is a cross-sectional view showing a battery laminate which is a lower member of a restraining member of a battery module arranged in the present embodiment, when being pressed in the stacking direction of battery cells.

[0050] Figure 28 It is a perspective view showing a state where, in a battery laminate which is a lower member of a restraining member of a battery module arranged in the present embodiment, when being pressed in the stacking direction of battery cells, the lower member is inserted from the lower side and the upper member is inserted from the upper side.

[0051] Figure 29 It is a cross-sectional view showing a state where, in a battery laminate which is a lower member of a restraining member of a battery module arranged in the present embodiment, when being pressed in the stacking direction of battery cells, the lower member is inserted from the lower side and the upper member is inserted from the upper side.

[0052] Figure 30 It is a perspective view showing a state where, when the lower member and the upper member of the restraining member of the battery module in the present embodiment are inserted into the battery laminate, a pressing jig composed of a round bar is retracted from the battery laminate. Detailed Embodiment

[0053] Hereinafter, embodiments of the present invention will be described. As Figure 1 shown, the battery pack 100 includes a restraining member 90, a housing 80, two battery laminates Bs, a flow path member 60, a cell restraining plate 30, and a lid 20.

[0054] Hereinafter, as Figure 2 shown, two specific directions orthogonal to each other in a horizontal plane are referred to as the "X direction" and the "Y direction". In addition, one direction of the X direction is referred to as the "X - direction", and the opposite direction of the X direction is referred to as the "X + direction". In addition, one direction of the Y direction is referred to as the "Y - direction", and the opposite direction of the Y direction is referred to as the "Y + direction".

[0055] As Figure 1 , Figure 2 shown, 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.

[0056] As Figure 6 shown, on the outer surface of the front wall of the housing 80 (the surface opposite to the battery laminate Bs side), a through - hole 801 is formed as described below, and the through - hole 801 is for a pressing jig 505 composed of a pressing rod (refer to Figure 15The battery stack Bs is pressurized by inserting the end plate 95. A spacer 85 as a pressurizing member is provided at a position opposite to the through hole 801, and the spacer 85 as a pressurizing member contacts a relatively thick convex portion of the end plate 95 described below and pressurizes the battery stack Bs.

[0057] A disc-shaped recessed portion 851 that is recessed toward the battery stack Bs is formed at a position of the spacer 85 that faces the through hole 801. The through hole 801 is provided with a pressure release valve (not shown).

[0058] like Figure 2 As shown in FIG. 1 , each battery stack Bs includes a plurality of battery cells 70 and a plurality of separators 79. Each battery stack Bs is restrained by a restraining member 90 and constitutes a battery module 200. By arranging an end plate 95 (see FIG. 1 ) at the end of the battery module 200 in the stacking direction, Figure 3 etc.), and constitute a stacked monomer ASSY.

[0059] Each battery cell 70 has a rectangular outer package that is elongated in the Y direction. Therefore, the "Y direction" can also be referred to as the "cell length direction". In each battery stack Bs, the battery cells 70 are stacked in the X direction. Therefore, the "X direction" can also be referred to as the "stacking direction". The partition 79 is a plate-shaped member extending in the Y direction and in the up-down direction, and is arranged between each two battery cells 70 arranged in the X direction. The material of the partition 79 is resin or the like.

[0060] Plate-shaped spacers 89 extending in the X direction and in the vertical direction are provided between the battery stack Bs on the Y-direction side and the case 80, between the two battery stacks Bs, and between the battery stack Bs on the Y+direction side and the case 80. The spacers 89 are made of resin or the like.

[0061] Each battery cell 70 has a positive electrode p (see Figure 2 , Figure 13 etc.), and a negative electrode n is provided at the end of the other direction of the Y direction on the upper surface of the outer package (reference Figure 13 Specifically, for a certain plurality of battery cells 70, a positive electrode p is arranged on the Y- direction side and a negative electrode n is arranged on the Y+ direction side. On the other hand, for the other battery cells 70, a negative electrode n is arranged on the Y- direction side and a positive electrode p is arranged on the Y+ direction side.

[0062] The electrodes p and n of the battery cells 70 adjacent in the Y direction or the X direction are electrically connected to each other by a conductive member (not shown). On the other hand, the positive electrode p of the battery cell 70 that is electrically most positive is electrically 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 that is electrically most negative is electrically connected to the negative electrode N of the entire battery pack 100 by another conductive member (not shown). By the above, in the present embodiment, all the battery cells 70 in the battery pack 100 are connected in series.

[0063] As Figure 2 shown, each battery cell 70 has a safety valve 76 at the center of the upper surface of the outer package, and the safety valve 76 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. Thus, 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 first damaged, thereby reducing the pressure.

[0064] The flow path member 60 is a member made of an insulator such as resin, and is provided for each battery laminate Bs. Each flow path member 60 is provided on the upper surface of the battery laminate Bs corresponding to itself.

[0065] As Figure 2 、 Figure 7 shown, etc., the single cell restraint plate 30 is a long plate-shaped member extending in the X direction, and is arranged at the center position of the upper surface of a pair of battery laminates Bs in the battery pack 100 and at both ends in the Y direction in parallel with the X direction. The single cell restraint plate 30 absorbs the height deviation of the battery cell 70 by sandwiching and restraining the deviation of the following upper member 92 of the restraint member 90 together with the cover 20 from above.

[0066] The material of the single cell restraint plate 30 is metal or the like. In the part of the single cell restraint plate 30 located above the flow path member 60, a flow path forming portion (not shown) for the refrigerant to flow through is formed. As Figure 7 shown, etc., the cover 20 is formed in a rectangular plate shape and covers the single cell restraint 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 in the flow path member 60.

[0067] The stacked single cell ASSY is configured such that end plates 95 are arranged at the ends in the stacking direction (the horizontal lateral direction) of the battery module 200, and includes a battery laminate Bs, a restraint member 90, and end plates 95. As Figure 9As shown in [figures], the restraining member 90 has a lower member 91 and an upper member 92, and the restraining member 90 maintains the state in which the battery cells 70 in the battery stack Bs are pressurized. The lower member 91 has a rectangular lower frame portion 911 having an opening portion 913 with a central opening, and side wall portions 912 standing up from a pair of long sides of the lower frame portion 911 toward the upper side, and restrains a plurality of battery cells 70 from the lower side of the battery stack Bs.

[0068] As Figure 9 , Figure 10 , Figure 12 As shown in [figures], etc., the lower frame portion 911 forms a seamless annular frame surrounding the periphery of the lower end portion of the battery stack Bs. With this configuration, the lower frame portion 911 is embedded and arranged so as to surround the periphery of the lower end portion of the battery stack Bs, whereby the lower frame portion 911 restrains the lower end portion of the battery stack Bs in the stacking direction of the plurality of battery cells 70 in the battery stack Bs.

[0069] The side wall portions 912 face and cover from the lower end portion to the vicinity of the upper end portion of the side surface portion of the battery stack Bs. As Figure 14 shown, at the upper end portion of the side wall portion 912, a plurality of trapezoidal protrusion portions 916 protrude upward from the upper end edge of the side wall portion 912 and are located at positions protruding more upward than the upper surface of the upper member 92. As Figure 13 shown, the upper member 92 and the lower member 91 are joined by embedding or adhesion at the side surface portion of the outer peripheral portion of the battery stack Bs. By joining the upper member 92 and the lower member 91, the restraining member 90 has a shape in which the upper surface and the lower surface are entirely open, and the end surfaces at both ends in the stacking direction of the battery stack Bs are open. In addition, for ease of explanation, in Figure 14 figures other than [figure], the protrusion portions 916 are omitted.

[0070] On the outer surface of the side wall portion 912, a plurality of trapezoidal convex portions 915 protrude in a direction away from the outer surface of the side wall portion 912. The convex portions 915 are configured to be appropriately flattened by being squeezed from the side by the side wall portion 912 of the lower member 91 toward the inside of the battery stack Bs. Thus, it is configured to be able to absorb the length deviation in the monomer length direction of the battery cell 70.

[0071] The upper member 92 has a rectangular upper frame portion 921 and restrains a plurality of battery cells 70 from the upper side of the battery stack Bs, and the rectangular upper frame portion 921 has an opening portion 923 with a central opening. As Figure 9 , Figure 11As shown, the upper frame portion 921 forms a seamless annular frame surrounding the upper end portion of the battery laminate Bs. With this configuration, the upper frame portion 921 is embedded and disposed so as to surround the upper end portion of the battery laminate Bs for one week. 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.

[0072] As Figure 13 shown, on the upper surface of the long side of the upper member 92, a plurality of trapezoidal convex portions 925 protrude upward. The convex portion 925 is configured to be appropriately flattened by being pressed from the upper side to the lower side by the single cell suppression plate 30 and the cover 20. Thus, the height deviation of the battery cell 70 is absorbed.

[0073] The end plate 95 is inserted into the front surface in the stacking direction of the plurality of battery cells 70, that is, the end surface of the battery laminate Bs in the same direction, and the plurality of battery cells 70 are inserted into the restraining member 90. Specifically, the end plate 95 is formed in a rectangular plate shape made of resin, 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 9 etc.) and the battery laminate Bs, and is fixed between the front wall of the housing 80 (refer to Figure 3 , Figure 6 etc.) and the battery laminate Bs.

[0074] The peripheral portion of the end plate 95 is formed to be thinner. Therefore, as Figure 3 shown, the portion other than the peripheral portion has a convex-shaped portion 951 that is relatively thick with respect to the peripheral portion. As Figure 3 etc. shown, the relatively thick convex-shaped portion 951 protrudes from the openings at the end surfaces of both ends of the restraining member 90 in the stacking direction of the battery laminate Bs, and protrudes from the restraining member 90 in the stacking direction. Thus, the convex-shaped portion 951 protrudes with respect to the restraining member 90 toward the spacer 85 that is a pressing member for pressing the battery laminate Bs.

[0075] Next, a method for assembling the battery pack 100 having the above configuration will be described. First, an outline (image) of the method for assembling the battery pack 100 will be described.

[0076] In the method for assembling the battery pack 100, first, as Figure 8 shown, in a state where the battery laminate Bs is pressed in the stacking direction of the battery cells 70 in the battery laminate Bs, the battery module 200 in a state of being restrained by the restraining member 90 is assembled. That is, as Figure 19 shown, the upper member 92 and the lower member 91 constituting the restraining member 90 are inserted into the battery laminate Bs in a state of being pressed in the stacking direction of the battery cells 70, as Figure 20As shown, for the upper member 92, it is inserted from the upper side, and for the lower member 91, it is inserted from the lower side. Then, as Figure 21 shown, the protrusion 916 of the lower member 91 is grasped and suspended by the grasping jig 507 and inserted into the housing 80, as Figure 22 shown, and stuffed into the housing 80 from the upper side.

[0077] The specific assembly method of the battery pack 100 is described as follows. In the assembly method of the battery pack 100, the assembly jig 500 shown in Figure 15 is used. The assembly jig 500 includes: a chassis 501, an abutment wall 502 or a round bar 502A that constitutes a pressing jig as a pressing device (refer to Figure 19 , Figures 26 - 30 ), an upward pushing jig 503, an upward push pin 504, and a pressing jig 505 that constitutes a pressing device and is made of a round bar.

[0078] In the assembly method of the battery pack 100, first, as Figure 23 shown, the lower frame portion 911 of the lower member 91 is set in the groove 5031 formed on the upper surface of the upward pushing jig 503. Secondly, as Figure 24 shown, the battery laminate Bs is inserted into the lower member 91 from the upper side of the lower member 91, and as Figure 25 shown, the battery laminate Bs is arranged at a position where it can be inserted into the lower member 91.

[0079] Next, as Figure 26 , Figure 27 shown, the battery laminate Bs is pressed from both sides in the stacking direction so as to be clamped by the pressing jig 505 and the round bar 502A in the stacking direction of the battery cells 70 of the battery laminate Bs. The pressing pressure at this time is 0.5 KN or more and 1.5 KN or less. This is because when the pressure is less than 0.5 KN, sufficient compression cannot be achieved, and once it exceeds 1.5 KN, the battery cells 70 constituting the battery laminate Bs will be damaged. In addition, when the abutment wall 502 that constitutes the pressing jig (refer to Figures 15 - 18 ) is used to replace the round bar 502A that constitutes the pressing jig (refer to Figure 19 , Figures 26 - 30 ), the battery laminate Bs is pressed from the side of the pressing jig 505.

[0080] Next, as Figure 28 , Figure 29 shown, when the battery laminate Bs is compressed to a specific distance by pressing, it is inserted into the lower member 91 in a manner that covers the plurality of battery cells 70 stacked in the horizontal direction as the lateral direction from the lower side. Specifically, as Figure 17 , Figure 18As shown, by raising the upward pushing jig 503 and the upward push pin 504, the lower member 91 is pushed upward to raise the lower member 91, and thus the lower member 91 is inserted into the battery laminate Bs from below.

[0081] Next, as Figure 28 shown, from the upper side of the plurality of battery cells 70 laminated in the horizontal direction as the lateral direction and being pressed, the upper member 92 covering the upper surface of the battery cells 70 is inserted. Specifically, as Figure 28 , Figure 29 shown, the upper member 92 is inserted from the upper side of the battery laminate Bs in such a manner as to surround the peripheral portion of the upper part of the battery laminate Bs in a circle around the upper side of the pressed battery laminate Bs.

[0082] And, the upper member 92 and the lower member 91 inserted above and below the battery laminate Bs are joined at the side surface portion of the outer peripheral portion of the battery laminate Bs by insertion or adhesion. And, as Figure 30 shown, the pressing jig 505 and the round bar 502A that are pressed in such a manner as to sandwich the battery laminate Bs are separated from each other. The above process is the process up to the completion of the assembly of the battery module 200 in the assembly method of the battery pack 100. In addition, on the outer surface of the end portion in the stacking direction of the battery laminate Bs, the end plate 95 is arranged in a state where the thicker portion of itself protrudes from the restraining member 90. After that, the battery module 200 is inserted into the housing 80, and the assembly of the battery pack 100 is completed.

[0083] The effects of using the above embodiment are as follows.

[0084] In the present embodiment, the restraining member 90 of the battery module 200 constituting the battery pack 100 is composed of the upper member 92 and the lower member 91. The upper member 92 is a frame member for restraining from the upper part side of the plurality of battery cells 70 laminated in the lateral direction, and the lower member 91 is a frame member for restraining from the lower part side of the plurality of battery cells 70 laminated in the lateral direction. The restraining member 90 restrains the plurality of battery cells 70 laminated in the stacking direction.

[0085] Thereby, it is possible to fix in a state of being restrained by the restraining member 90 as a frame body while compressing the plurality of battery cells 70. Therefore, it is possible to reduce the occupied volume of the accessory parts other than the battery cells 70 in the Intelligent Power Unit (IPU), thereby improving the monomer filling rate and being able to extend the cruising range of a Battery Electric Vehicle (BEV). In particular, since the upper member 92 and the lower member 91 are composed of a seamless frame body inserted into the plurality of laminated battery cells 70, it is possible to reliably restrain by the restraining member 90.

[0086] In addition, in the present embodiment, the upper member 92 and the lower member 91 of the battery module 200 are joined by being embedded or adhered to the side surfaces of the outer peripheries of the plurality of stacked battery cells 70. Thus, the lower member 91 can be configured to be located more outward than the upper member 92 and joined to the upper member 92. Therefore, it can be used for purposes other than using the lower member 91 as the restraining member 90 for restraint. For example, in a configuration where the upper end portion of the lower member 91 has a protrusion 916, the protrusion 916 can be grasped to carry the battery module 200 or the like. In addition, by the vertically integrated structure of the restraining member 90, the number of parts can be reduced, and thus cost reduction can be achieved.

[0087] In the present embodiment, the upper member 92 is configured to cover the upper end portions of the plurality of battery cells 70 stacked in the lateral direction and is open with respect to the upper surfaces of the plurality of battery cells 70 stacked in the lateral direction. In addition, the lower member 91 is configured to cover the lower end portions of the plurality of battery cells stacked in the lateral direction and is open with respect to the lower surfaces of the plurality of battery cells stacked in the lateral direction. In addition, the end portions of the restraining member 90 that restrain the stacked plurality of battery cells 70 are open in the stacking direction.

[0088] Thereby, it can be set as a frame structure that covers the upper and lower end portions of the entire battery stack Bs having the battery cells 70 and restrains them. When the reaction force decreases due to the compression of the battery cells 70, it is possible to suppress the movement of the restraining member 90 relative to the battery cells 70 of the battery stack Bs.

[0089] In the present embodiment, the method for assembling the battery module 200 includes the following steps: arranging a plurality of battery cells 70 in a stacked state in an assembly jig 500; pressurizing the arranged plurality of battery cells 70 in the stacking direction by using a pressurizing jig 505 as a pressurizing device; when the plurality of battery cells 70 are compressed to a specific distance by pressurization, embedding the lower member 91 so as to cover the plurality of battery cells 70 stacked in the horizontal direction as the lateral direction from below; embedding the upper member 92 that covers the upper surfaces of the battery cells 70 from the upper surfaces of the plurality of battery cells 70 stacked in the lateral direction that have been pressurized; and joining the upper member 92 and the lower member 91 embedded above and below the battery cells 70.

[0090] More specifically, for example, the lower side of the assembly jig 500 has an upper push jig 503 including an upper pusher 504 as a pusher, and a groove 5031 as a groove portion. In the process of inserting the lower member 91, the lower member 91 is set in the groove 5031, and the lower member 91 is pushed upward by the upper push jig 503 including the upper pusher 504, so that a plurality of stacked battery cells 70 are inserted into the lower member 91. Thus, the battery stack Bs composed of the stacked battery cells 70 can be fixed to the restraint member 90 without picking up the battery stack Bs. Therefore, a battery module 200 with good mountability can be manufactured.

[0091] In addition, in the present embodiment, in the process of pressurizing the battery cell 70, a plurality of stacked battery cells 70 are fixed to the assembly jig 500, and are pressurized and compressed by the pressurizing jig 505 with a pressure of 0.5 KN or more and 1.5 KN or less. Thus, the overall length of the battery stack Bs composed of a plurality of stacked battery cells 70 can be appropriately compressed to a specific distance (specific length).

[0092] In addition, in the present embodiment, in the process of pressurizing the battery stack Bs, a plurality of stacked battery cells 70 are pressurized from one side or both sides in the stacking direction. Thus, the battery stack Bs can be appropriately pressurized from one side or both sides.

[0093] In addition, in the present embodiment, in the process of inserting the lower member 91, the lower member 91 is raised from the lower side of the assembly jig 500 and inserted from the lower side of a plurality of stacked battery cells 70. More specifically, in the process of inserting the lower member 91, the lower member 91 is raised by the pusher 504 of the assembly jig 500. Thus, a configuration can be adopted in which the lower member 91 is raised without lowering the battery stack Bs, so that the configuration of the assembly jig 500 can be prevented from becoming complicated.

[0094] In addition, in the present embodiment, in the process of inserting the upper member 92, the upper member 92 is inserted from the upper side of a plurality of stacked battery cells 70 into which the lower member 91 is inserted from the lower side. Thus, the configuration of the assembly jig 500 can be prevented from becoming complicated, and the assembly jig 500 can be used to insert the upper member 92 from the upper side without raising the battery stack Bs.

[0095] In addition, in the present embodiment, in the process of joining the upper member 92 and the lower member 91, the upper member 92 and the lower member 91 are joined by fitting or welding. Thus, the number of parts can be reduced by the upper and lower integral structure of the restraint member 90, and cost reduction can be achieved.

[0096] In addition, in the present embodiment, in the battery pack 100, on the outer surface of the stacked monomer ASSY in the stacking direction of the plurality of battery cells 70, there is an end plate 95. The outer surface of the end plate 95 contacts a pressing jig 505 which is a pressing device for pressing the stacked monomer ASSY. The outer surface of the end plate 95 in contact with the pressing jig 505 has a convex-shaped portion 951 which is a convex-shaped portion facing the pressing jig 505.

[0097] Thereby, by pushing the convex-shaped portion 951, a compressive load generated by 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, by pressing integrally with the end plate 95, the stacked monomer ASSY can be uniformly pushed. In addition, by pressing the convex-shaped portion 951 of the end plate 95, when the stacked monomer ASSY is uniformly pushed, a limited range in the center of the battery cell 70 is pressed. As described above, the stacked monomer ASSY can be uniformly pushed. In addition, since the convex-shaped portion 951 can be pressed before being inserted into the housing 80, thereby compressing the plurality of battery cells 70, the restrictions during mass production can be reduced.

[0098] In addition, in the present embodiment, the end plate 95 is inserted into the end surfaces in the stacking direction of the plurality of battery cells 70, and the plurality of battery cells 70 are inserted into the restraining member 90. And 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. And the convex-shaped portion 951 which is the convex-shaped portion of the end plate 95 protrudes toward the pressing jig 505 which is a pressing member with respect to the restraining member 90.

[0099] Thereby, by pressing the convex-shaped portion 951 toward the battery cell 70, the battery cells 70 of the battery stack Bs can be uniformly pressed on the entire surface on the side of the end plate 95 opposite to the convex-shaped portion 951.

[0100] In addition, the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the scope capable of achieving the object of the present invention are included in the present invention.

[0101] For example, the restraining member may be configured to have a member in which one end side and the other end side are paired 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.

[0102] In addition, in the process of inserting the upper member 92, the upper member 92 may be inserted from the upper side of the plurality of stacked battery cells before inserting the lower member 91 from the lower side, instead of inserting the upper member 92 from the upper side of the plurality of stacked battery cells after inserting the lower member 91 from the lower side.

[0103] Reference numeral

[0104] 70 Battery cell

[0105] 80 Housing (accommodating housing)

[0106] 85 Spacer

[0107] 90 Restraining member (cell ASSY housing)

[0108] 91 Lower member (other end side member)

[0109] 92 Upper member (one end side member)

[0110] 95 End plate

[0111] 100 Battery pack

[0112] 200 Battery module

[0113] 500 Assembly jig

[0114] 504 Upper push pin

[0115] 505 Pressing jig (pressing device)

[0116] 801 Through hole

[0117] 913, 923 Opening

[0118] 916 Protrusion (grasped portion)

[0119] 951 Convex-shaped portion (convex-shaped part)

Claims

1. A battery module, comprising: Multiple battery cells stacked in layers; and, a restraining member for restraining the stacked plurality of battery cells along a stacking direction of the plurality of battery cells; and The restraining member is composed of a first end member and a second end member to restrain the plurality of battery cells. The one end side member is a frame member for restraining the plurality of battery cells stacked in the lateral direction from the upper side. The other end side member is a frame member for restraining the plurality of stacked battery cells from the lower side in the lateral direction. The one end side member and the other end side member are joined at the outer periphery of the plurality of stacked battery cells. The restraining member restrains the stacked plurality of battery cells in a stacking direction.

2. The battery module according to claim 1, wherein: The stacked plurality of battery cells are in a pressurized state.

3. The battery module according to claim 1, wherein: The one end side member and the other end side member are joined to side surfaces of outer peripheral portions of the plurality of stacked battery cells.

4. The battery module according to claim 3, wherein: The other end side member is located outside the one end side member and is joined to the one end side member.

5. The battery module according to claim 1, wherein: The one end side member and the other end side member are joined by fitting or bonding.

6. The battery module according to claim 1, wherein: The one-end side member is configured to cover the upper end portions of the plurality of battery cells stacked in the lateral direction and is open to the upper surface of the plurality of battery cells stacked in the lateral direction. The other end side member is configured to cover lower end portions of the plurality of battery cells stacked in the lateral direction, and is open with respect to lower surfaces of the plurality of battery cells stacked in the lateral direction.

7. The battery module according to claim 1, wherein: The restraining member restraining the stacked plurality of battery cells has an opening at its end in the stacking direction.

8. The battery module according to claim 1, wherein: The other end side member is configured to cover the lower ends of the plurality of stacked battery cells in the lateral direction to the side surfaces, and the upper end of the other end side member is located above the upper surface of the one end side member.

9. The battery module according to claim 8, wherein: The other end side member has a protrusion at an upper end portion thereof, and the protrusion is located above an upper surface of the one end side member.

10. A battery module assembly method, comprising installing a restraining member on a plurality of stacked battery cells, wherein the restraining member is composed of a first end member and a second end member, and the battery module assembly method comprises the following steps: placing the plurality of battery cells in a stacked state on an assembly jig; Using a pressurizing device to pressurize the plurality of battery cells that have been arranged in the above-mentioned manner in a stacking direction; When the plurality of battery cells are compressed to a specific distance by applying pressure, the other end side member is embedded in a manner covering the plurality of battery cells stacked in the lateral direction from the bottom side; embedding the one-end side member covering the upper surface of the battery cell from the upper surface of the plurality of battery cells stacked in the lateral direction which are pressurized; and, The one end side member into which the upper and lower parts of the battery cell are inserted is joined to the other end side member.

11. The method for assembling a battery module according to claim 10, wherein: The lower side of the assembly jig has an upward push jig including a push pin and a groove. In the step of inserting the other end side member, the other end side member is placed in the groove, and the other end side member is pushed up by the push-up jig including the push pin, so that the stacked plurality of battery cells are inserted into the other end side member.

12. The method for assembling a battery module according to claim 10, wherein: In the pressurizing step, the plurality of stacked battery cells are pressurized from one side or both sides in the stacking direction.

13. The method for assembling a battery module according to claim 11, wherein: In the step of inserting the one end side member, the one end side member is inserted from the upper side of the plurality of stacked battery cells after the other end side member is inserted from the lower side, or from the upper side of the plurality of stacked battery cells before the other end side member is inserted from the lower side.

14. The method for assembling a battery module according to claim 10, wherein: In the step of joining the one end side member and the other end side member, the one end side member and the other end side member are joined by fitting or welding.

15. The method for assembling a battery module according to claim 10, wherein: The one end side member and the other end side member respectively constitute a frame body having an annular shape and fixing the plurality of battery cells.

16. The method for assembling a battery module according to claim 10, wherein: The other end side member has a grasped portion that can be grasped when the stacked plurality of battery cells to which the restraint member is attached are housed in a case of a battery module.

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