Battery module

Abstract

To provide a battery module that can better maintain the cell stack. [Solution] The battery module 10 comprises a cell stack 12 having battery cells 18 and heat exchangers 20 stacked on the battery cells; a holding mechanism 17 having a pair of holding parts 35 that hold the cell stack by pressing both ends of the cell stack inward in the stacking direction, and a connecting member 38 that connects the pair of holding parts to each other; and a detachment prevention mechanism 60 provided on the heat exchanger that prevents the heat exchanger from detaching from the cell stack by contacting the connecting member.

Description

Technical Field

[0001] The present disclosure relates to a battery module.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2023-101130 discloses a battery module. The battery module includes a cell stack and a holding mechanism. The cell stack is formed by laminating battery cells and a heat exchanger. The holding mechanism holds the cell stack by applying a clamping load from both sides in the stacking direction of the cell stack. The holding mechanism prevents the movement of the battery cells and the heat exchanger.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a need for a technology that can hold the cell stack better.

[0005] The present disclosure aims to solve the above-described problems.

Means for Solving the Problems

[0006] A battery module according to an aspect of the present disclosure includes a cell stack having a battery cell and a heat exchanger laminated on the battery cell, a pair of holding portions that hold the cell stack by pressing both end portions of the cell stack in the stacking direction inward in the stacking direction, a holding mechanism having a connecting member that connects the pair of holding portions to each other, and a detachment prevention mechanism provided on the heat exchanger and preventing the heat exchanger from detaching from the cell stack by abutting against the connecting member.

Effects of the Invention

[0007] According to this disclosure, the cell laminate can be held securely. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view of a battery module according to an embodiment. [Figure 2] Figure 2 is an exploded perspective view of the cell stack. [Figure 3] Figure 3 is a cross-sectional view along the line III-III in Figure 1. [Figure 4] Figure 4A shows the detachment prevention mechanism provided in the first heat exchanger, and Figure 4B shows the detachment prevention mechanism provided in the second heat exchanger. [Figure 5] Figure 5A shows another example configuration of the detachment prevention mechanism provided in the first heat exchanger, and Figure 5B shows another example configuration of the detachment prevention mechanism provided in the second heat exchanger. [Figure 6] Figure 6 is a perspective view of the battery module according to the first modified example. [Figure 7] Figure 7 is a cross-sectional view along the line VII-VII in Figure 6. [Figure 8] Figure 8 is a cross-sectional view of a battery module according to the second modified example. [Figure 9] Figure 9 is a schematic diagram of an aircraft equipped with a battery module. [Modes for carrying out the invention]

[0009] When the cell stack is held only by the frictional force due to the pressing force applied by the holding mechanism, if a force exceeding the holding force due to friction acts on the cell stack, the heat exchanger will be displaced in a direction intersecting the stacking direction of the cell stack. To prevent this displacement, it is conceivable to increase the pressing force (tightening force) of the holding mechanism, but this requires increasing the rigidity of the battery cells and the heat exchanger. However, if the rigidity of the battery cells and the heat exchanger is increased, there is a concern that the tightening force acting on the battery cells will become excessive when the battery cells expand. According to the embodiment shown below, it is possible to hold the cell stack well.

[0010] As shown in Figure 9, the battery module 10 according to this embodiment is mounted on, for example, an aircraft 102 as a mobile unit 100. The aircraft 102 is, for example, an electric vertical take-off and landing aircraft (eVTOL). The aircraft 102 includes a fuselage 104, a plurality (e.g., four) of VTOL rotors 106, and a plurality (e.g., two) of cruise rotors 108.

[0011] The VTOL rotor 106 generates upward thrust relative to the aircraft 102. The cruise rotor 108 generates horizontal thrust relative to the aircraft 102. The battery module 10 is located inside the aircraft body 104. The battery module 10 supplies power to electric motors (not shown) that drive the VTOL rotor 106 and the cruise rotor 108, respectively. The mobile body 100 may be, for example, a vehicle, a ship, etc. Note that the battery module 10 is not limited to being mounted on the mobile body 100.

[0012] As shown in Figure 1, the battery module 10 comprises a cell stack 12 and a plurality of battery frames 16. In this embodiment, the plurality of battery frames 16 constitute a holding mechanism 17 that holds the cell stack 12.

[0013] As shown in FIG. 2, the cell stack 12 includes a plurality of battery cells 18 and a plurality of heat exchangers 20. A plurality of battery cells 18 arranged in the direction of arrow X form one cell row 19. In the present embodiment, four cell rows 19 are arranged in the direction of arrow Y. The number of cell rows 19 may be 3 or less, or 4 or more. In the battery module 10, only one cell row 19 may be provided.

[0014] The plurality of battery cells 18 and the plurality of heat exchangers 20 are arranged (stacked) in the direction of arrow X. Hereinafter, the X direction is also referred to as the "stacking direction". Also, among the X direction, the direction toward the center of the battery module 10 is expressed as the "inner side in the stacking direction". Among the X direction, the direction away from the center of the battery module 10 is expressed as the "outer side in the stacking direction".

[0015] The battery cell 18 is a laminated battery. The battery cell 18 is formed in a rectangular plate shape. A plurality of terminal portions 22 project from one side of the battery cell 18 in the direction of arrow Z. The plurality of battery cells 18 are connected in series with each other via the terminal portions 22. Note that the terminal portions 22 are conceptually illustrated. Electric connection members (not shown) are joined to the plurality of terminal portions 22.

[0016] The plurality of heat exchangers 20 include a plurality of first heat exchangers 20a and a plurality of second heat exchangers 20b.

[0017] Each of the plurality of first heat exchangers 20a has a heat exchange plate 24 and a pair of headers 25.

[0018] The heat exchange plate 24 is a plate-like water jacket. The heat exchange plate 24 is made of a metal material such as aluminum or copper, for example. The heat exchange plate 24 extends in the direction of arrow Y. The pair of headers 25 are provided at both ends of the heat exchange plate 24. The pair of headers 25 are made of plastic, for example. The pair of headers 25 are a water supply / drain header 26 and a turn header 28.

[0019] Inside the heat exchange plate 24, a flow path through which cooling water circulates is formed. Although not shown in detail, this flow path has an outward flow path that flows cooling water from the water supply / drain header 26 toward the turn header 28, and a return flow path that flows cooling water from the turn header 28 toward the water supply / drain header 26.

[0020] The water supply / drain header 26 is one of a pair of headers 25 provided in the first heat exchanger 20a. The water supply / drain header 26 is provided at one end (Y1 direction side) in the longitudinal direction (arrow Y direction) of the heat exchange plate 24. The water supply / drain header 26 supplies and discharges cooling water to and from the heat exchange plate 24. The water supply / drain header 26 has a water supply port 30 and a drain port 32.

[0021] The water supply port 30 is provided at the upper part of the water supply / drain header 26. The water supply port 30 supplies cooling water to the outward flow path of the heat exchange plate 24. The water supply ports 30 of the first heat exchangers 20a adjacent to each other are connected to each other in a liquid-tight manner.

[0022] The drain port 32 discharges cooling water from the return flow path of the heat exchange plate 24. The drain port 32 is provided at the lower part of the water supply / drain header 26. The drain ports 32 of the first heat exchangers 20a adjacent to each other are connected to each other in a liquid-tight manner. Incidentally, contrary to the above-described configuration, the water supply port 30 may be provided at the lower part of the water supply / drain header 26, and the drain port 32 may be provided at the upper part of the water supply / drain header 26.

[0023] Although not shown in detail, the water supply ports 30 of the first heat exchangers 20a adjacent to each other are connected so as to be relatively movable in the X direction so that the expansion of the battery cell 18 in the X direction due to heat generation or deterioration of the battery cell 18 can be absorbed. Similarly, the drain ports 32 of the first heat exchangers 20a adjacent to each other are connected so as to be relatively movable in the X direction.

[0024] The turn header 28 is the other of a pair of headers 25 provided in the first heat exchanger 20a. The turn header 28 is located at the other end (Y2 direction side) in the longitudinal direction of the heat exchange plate 24. Therefore, the heat exchange plate 24 is positioned between the supply and drain header 26 and the turn header 28. The turn header 28 receives cooling water from the supply channel of the heat exchange plate 24 and directs the cooling water into the return channel of the heat exchange plate 24.

[0025] The second heat exchanger 20b, like the first heat exchanger 20a, has a heat exchange plate 24 and a pair of headers 25 (a water supply / drainage header 26 and a turn header 28). However, the orientation of the second heat exchanger 20b in the Y direction is different from that of the first heat exchanger 20a. For this reason, in the second heat exchanger 20b, the water supply / drainage header 26 is located on the Y2 direction side of the heat exchange plate 24, and the turn header 28 is located on the Y1 direction side of the heat exchange plate 24.

[0026] The first heat exchanger 20a and the second heat exchanger 20b are arranged alternately in the direction of arrow X. Therefore, one of the supply and drainage headers 26 of the first heat exchanger 20a and the second heat exchanger 20b and the other of the turn headers 28 of the first heat exchanger 20a and the second heat exchanger 20b are adjacent to each other in the stacking direction (X direction).

[0027] As shown in Figure 3, two battery cells 18 are stacked in the direction of arrow X between the adjacent first heat exchanger 20a and second heat exchanger 20b.

[0028] As shown in Figure 1, in this embodiment, four battery frames 16 are provided corresponding to four cell rows 19. The number of battery frames 16 may be three or less, or five or more, depending on the number of cell rows 19.

[0029] As shown in Figure 3, each of the multiple battery frames 16 constituting the holding mechanism 17 includes a pair of holding plates 34, a pair of pressure receiving plates 36, and four connecting members 38 (see Figure 1). The pair of holding plates 34 are located at the ends of the battery module 10 in the direction of arrow X.

[0030] In this embodiment, the pair of retaining plates 34 are a pair of retaining parts 35 that hold the cell laminate 12. The pair of retaining plates 34 are located outside the cell laminate 12 in the stacking direction. The pair of retaining plates 34 hold the cell laminate 12 by pressing both ends of the cell laminate 12 inward in the stacking direction.

[0031] More specifically, the holding plate 34 presses the cell laminate 12 in the stacking direction via the pressure receiving plate 36. The pressure receiving plate 36 is positioned between the holding plate 34 and the cell laminate 12.

[0032] The connecting member 38 connects the pair of retaining plates 34 to each other so that a clamping load (compressive load) is applied from the pair of retaining plates 34 to the cell stack 12. This suppresses the expansion of the battery cells 18.

[0033] The retaining plate 34 is made of, for example, a titanium alloy. However, the retaining plate 34 may also be made of a metal material other than a titanium alloy.

[0034] As shown in Figure 1, the retaining plate 34 is formed in an X shape when viewed from the thickness direction of the retaining plate 34 (direction of arrow X). The retaining plate 34 has a point-symmetric shape when viewed from the direction of arrow X. The retaining plate 34 includes a central plate portion 40 and four arm portions 42.

[0035] The central part 40 of the plate is a pressing part 41 that presses the cell stack 12 in the stacking direction via the pressure receiving plate 36. The central part 40 of the plate is located in the center of the holding plate 34.

[0036] The four arm sections 42 extend radially from the central section 40 of the plate. The four arm sections 42 are provided at equal intervals in the circumferential direction of the central section 40 of the plate. The arm sections 42 are leaf spring sections that elastically deform when a clamping load is applied to the cell laminate 12. Note that the number of arm sections 42 is not limited to four, but may be three or five or more.

[0037] An attachment portion 44 is provided at the end of the arm portion 42 in the extending direction. A connecting member 38 is connected to the attachment portion 44. As shown in Figure 3, the attachment portion 44 has an insertion hole 45 through which the bolt portion 48 of the connecting member 38 is inserted.

[0038] As shown in Figure 1, the mounting portion 44 is located outward from the cell stack 12 when viewed from the stacking direction of the battery cells 18 (arrow X direction). The mounting portion 44 does not overlap with the terminal portion 22 when viewed from the arrow X direction.

[0039] The pressure-receiving plate 36 is a pressing plate that evenly applies the clamping load acting from the holding plate 34 to the cell stack 12. The pressure-receiving plate 36 is formed in a rectangular shape. As shown in Figure 3, the first surface 36a of the pressure-receiving plate 36 facing the cell stack 12 is in surface contact with the end face of the cell stack 12. The second surface 36b of the pressure-receiving plate 36 facing the opposite direction from the cell stack 12 is in surface contact with the central part 40 of the holding plate 34. Note that the battery frame 16 does not necessarily have to have the pressure-receiving plate 36.

[0040] As shown in Figure 1, with the retaining plate 34 attached to the pressure receiving plate 36, the four arm portions 42 extend so as to overlap the four corners of the pressure receiving plate 36 when viewed from the direction of arrow X. As shown in Figure 3, with the retaining plate 34 attached to the pressure receiving plate 36, a gap is provided between the arm portions 42 and the corners of the pressure receiving plate 36. As shown in Figure 1, with the retaining plate 34 attached to the pressure receiving plate 36, the four mounting portions 44 are located outward from the pressure receiving plate 36 when viewed from the direction of arrow X.

[0041] The connecting member 38 is located outside the cell stack 12. The connecting member 38 is located inward in the Y direction from the pair of headers 25. As shown in Figure 3, the connecting member 38 includes a connecting shaft 46, two bolt portions 48, and two nuts 50.

[0042] The connecting shaft 46 extends along the stacking direction (X direction) of the battery cells 18. The connecting shaft 46 is made of a metal material such as stainless steel. As shown in Figures 4A and 4B, the cross-sectional shape of the connecting shaft 46 in a plane perpendicular to the axial direction of the connecting shaft 46 is circular. That is, the connecting shaft 46 is a cylindrical rod. Note that the cross-sectional shape of the connecting shaft 46 is not limited to a circle; for example, it may be elliptical, square, or the like.

[0043] As shown in Figure 3, the bolt portion 48 protrudes from the axial end face of the connecting shaft 46. The bolt portion 48 is inserted through the insertion hole 45 of the mounting portion 44. The nut 50 is screwed onto the bolt portion 48. The mounting portion 44 is located between the nut 50 and the connecting shaft 46.

[0044] When the nut 50 is tightened onto the bolt portion 48, the retaining plate 34 is pressed toward the pressure receiving plate 36. At this time, the four arm portions 42 (see Figure 1) undergo elastic deformation. The elastic force (spring force) of the four arm portions 42 is applied to the cell stack 12 as a tightening load via the pressure receiving plate 36. This tightening load is the holding force of the retaining plate 34 toward the cell stack 12. The battery frame 16 holds the cell stack 12 by the frictional force generated by the force with which the retaining plate 34 pushes the cell stack 12 toward the cell stack 12 toward the pressure receiving plate 36.

[0045] As shown in Figures 4A and 4B, the battery module 10 is further equipped with a detachment prevention mechanism 60. The detachment prevention mechanism 60 is a structure that prevents the heat exchanger 20 from falling off the cell stack 12 (see Figure 1). Figure 4A shows a first heat exchanger 20a equipped with the detachment prevention mechanism 60. Figure 4B shows a second heat exchanger 20b equipped with the detachment prevention mechanism 60.

[0046] As shown in Figures 4A and 4B, the detachment prevention mechanism 60 protrudes from the periphery of the heat exchanger 20 (first heat exchanger 20a, second heat exchanger 20b) in a direction perpendicular to the X direction. Specifically, as shown in Figure 2, the detachment prevention mechanism 60 protrudes from the periphery of the heat exchanger 20 in directions along the Y and Z directions.

[0047] The detachment prevention mechanisms 60 are provided at the four corners of the heat exchange plate 24. As described above, a water supply and drainage header 26 and a turn header 28 are provided at both ends of the heat exchange plate 24. Therefore, of the four detachment prevention mechanisms 60 (detachment prevention mechanisms 60a, 60b, 60c, 60d), two are provided at the top and bottom of the water supply and drainage header 26, respectively. Of the four detachment prevention mechanisms 60, the remaining two are provided at the top and bottom of the turn header 28, respectively. As described above, if the material of the header 25 (water supply and drainage header 26, turn header 28) is plastic, the detachment prevention mechanisms 60 are provided on the header 25 by integral molding.

[0048] As shown in Figures 4A and 4B, each of the four detachment prevention mechanisms 60 protrudes toward the connecting member 38 (connecting members 38a, 38b, 38c, 38d) adjacent to each of these detachment prevention mechanisms 60. More specifically, each of the four detachment prevention mechanisms 60 protrudes toward the connecting shaft 46 (connecting shafts 46a, 46b, 46c, 46d) of the connecting member 38 adjacent to each of these detachment prevention mechanisms 60. Note that when there is no displacement of the heat exchanger 20 in the direction perpendicular to the X direction, a gap exists between the connecting shaft 46 and the detachment prevention mechanism 60.

[0049] As shown in Figures 4A and 4B, in the heat exchanger 20, a detachment prevention mechanism 60a is provided at the top of the header 25 on the Y1 direction side (the water supply and drainage header 26 of the first heat exchanger 20a and the turn header 28 of the second heat exchanger 20b). The connecting shaft 46a is close to the top of the header 25 on the Y1 direction side. That is, the connecting shaft 46a is one of the connecting shafts 46 located on the Y1 direction side among a plurality of connecting shafts 46 located above the cell stack 12 (see Figure 1). The detachment prevention mechanism 60a protrudes from the top of the header 25 on the Y1 direction side toward the connecting shaft 46a.

[0050] As shown in Figures 4A and 4B, in the heat exchanger 20, a detachment prevention mechanism 60b is provided at the lower part of the header 25 on the Y1 direction side. The connecting shaft 46b is close to the lower part of the header 25 on the Y1 direction side. That is, the connecting shaft 46b is one of the connecting shafts 46 located below the cell stack 12, and is located on the Y1 direction side (see Figure 1). The detachment prevention mechanism 60b protrudes from the lower part of the header 25 on the Y1 direction side toward the connecting shaft 46b.

[0051] As shown in Figures 4A and 4B, in the heat exchanger 20, a detachment prevention mechanism 60c is provided at the top of the header 25 on the Y2 direction side (the turn header 28 of the first heat exchanger 20a and the water supply / drainage header 26 of the second heat exchanger 20b). The connecting shaft 46c is located close to the top of the header 25 on the Y2 direction side. That is, the connecting shaft 46c is one of the connecting shafts 46 located on the Y2 direction side among a plurality of connecting shafts 46 located above the cell stack 12 (see Figure 1). The detachment prevention mechanism 60c protrudes from the top of the header 25 on the Y2 direction side toward the connecting shaft 46c.

[0052] As shown in Figures 4A and 4B, in the heat exchanger 20, a detachment prevention mechanism 60d is provided at the lower part of the header 25 on the Y2 direction side. The connecting shaft 46d is close to the lower part of the header 25 on the Y2 direction side. That is, the connecting shaft 46d is one of the connecting shafts 46 located below the cell stack 12, and is located on the Y2 direction side (see Figure 1). The detachment prevention mechanism 60d protrudes from the lower part of the header 25 on the Y2 direction side toward the connecting shaft 46d.

[0053] By providing the detachment prevention mechanism 60 on the heat exchanger 20 in this manner, when the heat exchanger 20 is displaced due to vibration or other shocks in a direction perpendicular to the X direction, the detachment prevention mechanism 60 will come into contact with the connecting shaft 46 facing the detachment prevention mechanism 60. The contact of the detachment prevention mechanism 60 with the connecting shaft 46 prevents the heat exchanger 20 from detaching from the cell stack 12.

[0054] Furthermore, the detachment prevention mechanism 60 is not limited to contacting the connecting shaft 46 when the heat exchanger 20 is misaligned. The detachment prevention mechanism 60 may also contact the connecting shaft 46 when the heat exchanger 20 is not misaligned.

[0055] Furthermore, the detachment prevention mechanism 60 is not limited to being provided at the four corners of the heat exchange plate 24. The detachment prevention mechanism 60 may be provided at two or three of the four corners of the heat exchange plate 24.

[0056] The detachment prevention mechanism 60 includes an engaging claw 62. The engaging claw 62 is provided at the protruding end (tip) of the detachment prevention mechanism 60. The engaging claw 62 is engageable with the connecting member 38. Specifically, the engaging claw 62 is formed in an arc shape so as to be engageable with the connecting shaft 46. This makes it easier for the engaging claw 62 to come into contact with the connecting shaft 46.

[0057] As shown in Figure 4A, the contact portion of the anti-detachment mechanism 60 that contacts the connecting shaft 46 is treated with a surface treatment to reduce the coefficient of friction. Specifically, the contact portion is provided with a low-friction material 64, which is a substance that reduces the coefficient of friction. More specifically, the contact surface 66 of the engaging claw 62 that contacts the connecting shaft 46 is provided with the low-friction material 64. Examples of low-friction material 64 include coatings such as fluororesins such as Teflon (registered trademark), polyacetal, and polyamide. The low-friction material 64 may also be a lubricant such as grease. This makes it easier for the first heat exchanger 20a and the second heat exchanger 20b to move relative to each other in the X direction when the battery cell 18 expands in the X direction due to heat generation or deterioration. In addition, it is possible to suppress wear of the anti-detachment mechanism 60 when it contacts the connecting shaft 46.

[0058] Figure 4A illustrates a case where a low-friction material 64 is provided on the contact surface 66 of the engaging claw 62 of the detachment prevention mechanism 60a. In this embodiment, the low-friction material 64 is also provided on the contact surface 66 of the engaging claw 62 of the other detachment prevention mechanisms 60b, 60c, and 60d.

[0059] As shown in Figures 5A and 5B, the detachment prevention mechanism 60 may have an insertion hole 68 through which the connecting shaft 46 is inserted, instead of the engaging claw 62 (see Figures 4A and 4B). The insertion hole 68 penetrates in the X direction at the protruding end of the detachment prevention mechanism 60. The inner diameter of the insertion hole 68 is larger than the outer diameter of the connecting shaft 46. As a result, when the heat exchanger 20 is displaced in a direction perpendicular to the X direction, the connecting shaft 46 comes into contact with the inner circumferential surface 69 of the insertion hole 68. By the connecting shaft 46 coming into contact with the inner circumferential surface 69 of the insertion hole 68, the heat exchanger 20 can be effectively prevented from detaching from the cell stack 12.

[0060] The inner circumferential surface 69 of the insertion hole 68 is a contact surface that abuts against the connecting shaft 46 of the detachment prevention mechanism 60. The inner circumferential surface 69 of the insertion hole 68 is subjected to a surface treatment to reduce the coefficient of friction. That is, a low-friction material 64 is provided on the inner circumferential surface 69 of the insertion hole 68.

[0061] Figure 5A illustrates a case where a low-friction material 64 is provided on the inner circumferential surface 69 of the insertion hole 68 of the detachment prevention mechanism 60a. In this embodiment, the low-friction material 64 is also provided on the inner circumferential surface 69 of the insertion holes 68 of the other detachment prevention mechanisms 60b, 60c, and 60d.

[0062] In this embodiment, detachment prevention mechanisms 60 may be provided at the four corners of the heat exchange plate 24. As described above, since the material of the heat exchange plate 24 is metal, the detachment prevention mechanisms 60 are provided at the four corners of the heat exchange plate 24 by welding.

[0063] This embodiment provides the following effects.

[0064] Even if the battery module 10 is subjected to an impact exceeding expectations, as shown in Figures 4A to 5B, the detachment prevention mechanism 60 contacts the connecting member 38, preventing the heat exchanger 20 from detaching from the cell stack 12 (see Figure 1). Furthermore, since there is no need to increase the clamping force by the holding mechanism 17, it is possible to prevent the clamping force acting on the battery cells 18 from becoming too large when the battery cells 18 expand due to heat generation or deterioration. Therefore, in this embodiment, the cell stack 12 can be held securely.

[0065] The detachment prevention mechanism 60 protrudes from the periphery of the heat exchanger 20 in a direction perpendicular to the X direction. As a result, even if the heat exchanger 20 is displaced in a direction perpendicular to the X direction, the detachment prevention mechanism 60 provided on the heat exchanger 20 will come into contact with the connecting member 38, thereby effectively preventing the heat exchanger 20 from detaching from the cell laminate 12.

[0066] As shown in Figures 4A and 4B, the detachment prevention mechanism 60 is equipped with an engaging claw 62 that can engage with the connecting shaft 46 of the connecting member 38. As a result, when the heat exchanger 20 is displaced in a direction perpendicular to the X direction, the engaging claw 62 engages with the connecting shaft 46. This makes it possible to more effectively prevent the heat exchanger 20 from detaching from the cell laminate 12 (see Figure 1).

[0067] As shown in Figures 5A and 5B, the detachment prevention mechanism 60 is provided with an insertion hole 68 through which the connecting shaft 46 of the connecting member 38 is inserted. As a result, when the heat exchanger 20 is displaced in a direction perpendicular to the X direction, the connecting shaft 46 comes into contact with the inner circumferential surface 69 of the insertion hole 68. This makes it possible to more effectively prevent the heat exchanger 20 from detaching from the cell laminate 12 (see Figure 1).

[0068] As shown in Figures 4A to 5B, the heat exchanger 20 has a rectangular heat exchange plate 24, and the detachment prevention mechanism 60 is provided at the four corners of the heat exchange plate 24. As a result, when the heat exchanger 20 is displaced in a direction perpendicular to the X direction, one of the detachment prevention mechanisms 60 will come into contact with the connecting shaft 46. This effectively prevents the heat exchanger 20 from detaching from the cell stack 12 (see Figure 1).

[0069] The detachment prevention mechanism 60 is provided on each of the pair of headers 25 located at both ends of the heat exchange plate 24. This prevents the heat exchanger 20 from detaching from the cell stack 12 without reducing the cooling performance of the battery cells 18 by the heat exchange plate 24.

[0070] The contact surface (contact surface 66, inner circumferential surface 69 of the insertion hole 68) of the detachment prevention mechanism 60, which is the surface that comes into contact with the connecting member 38, is treated with a surface treatment that reduces the coefficient of friction. This prevents the detachment prevention mechanism 60 from wearing down due to contact with the connecting member 38.

[0071] When there is no displacement of the heat exchanger 20 in the direction perpendicular to the X direction, a gap exists between the connecting shaft 46 and the detachment prevention mechanism 60. This makes it easier for the heat exchanger 20 to move relative to the X direction when the battery cell 18 expands in the X direction due to heat generation or deterioration. Also, when the heat exchanger 20 is displaced in the direction perpendicular to the X direction, the detachment prevention mechanism 60 easily comes into contact with the connecting shaft 46.

[0072] The battery module 10A according to the first modified example will be described with reference to Figures 6 and 7. The battery module 10A according to the first modified example comprises a cell stack 12 and a holding mechanism 17A.

[0073] The holding mechanism 17A comprises a plurality of battery frames 16 and a pair of holding parts 35A. In the first modified example, the holding mechanism 17A for holding the cell stack 12 is composed of a plurality of battery frames 16, a pair of holding parts 35A, and a plurality of connecting members 38. Each of the pair of holding parts 35A comprises a plurality of damper members 51 and a support member 56.

[0074] The cell laminate 12 is pressed inward in the stacking direction by a plurality of damper members 51 of a pair of holding portions 35A. Specifically, each of the plurality of damper members 51 of the pair of holding portions 35A presses the cell laminate 12 inward in the stacking direction via a holding plate 34 and a pressure receiving plate 36. For this reason, the holding plate 34 is positioned between the cell laminate 12 and the damper members 51.

[0075] The damper member 51 presses the retaining plate 34 toward the cell laminate 12. The damper member 51 has an elastic body 52 and a holder 54.

[0076] The elastic body 52 is the damper body. The elastic body 52 is made of a material that exhibits rubber elasticity. The elastic body 52 is made of rubber material or elastomer material. The elastic body 52 is in contact with the retaining plate 34. When viewed from the stacking direction, the elastic body 52 is circular in shape. However, when viewed from the stacking direction, the elastic body 52 may be elliptical or polygonal in shape.

[0077] The elastic body 52 is in contact with the central portion 40 of the retaining plate 34. The holder 54 holds the elastic body 52. ​​The holder 54 is made of a material that is more rigid than the elastic body 52. ​​The holder 54 is, for example, made of metal.

[0078] Multiple damper members 51 are arranged at intervals from each other in the Y direction. Specifically, the multiple damper members 51 are each positioned so as to overlap with multiple cell rows 19 when viewed from the stacking direction. Since there are four cell rows 19 arranged in the Y direction, in the first modified example, there are also four damper members 51 arranged in the Y direction.

[0079] Each of the pair of support members 56 supports a plurality of damper members 51. Each of the pair of support members 56 has an opposing surface 560 that faces the retaining plate 34. The damper members 51 are fixed to the opposing surface 560. Therefore, the damper members 51 are positioned between the retaining plate 34 and the support members 56. Although not shown in detail, the plurality of damper members 51 are fixed to the pair of support members 56 by appropriate fixing parts (bolts, etc.). Each of the pair of support members 56 is fixed to the floor 110 of the object on which the battery module 10A is installed (for example, the mobile body 100 shown in Figure 9).

[0080] The first modification produces the following effects:

[0081] As shown in Figures 6 and 7, each of the pair of holding parts 35A has a damper member 51 that presses the cell stack 12 in the X direction and a support member 56 that supports the damper member 51. As a result, the holding mechanism 17A having the damper member 51 presses the cell stack 12 inward in the stacking direction, thereby increasing the resonance frequency of the cell stack 12 in the stacking direction. Therefore, resonance of the cell stack 12 due to external vibrations is suppressed, and the cell stack 12 can be protected. Furthermore, since the support member 56 supports the damper member 51, in addition to the tightening load from the pair of holding plates 34, a tightening load from the damper member 51 supported by the support member 56 can be applied to the cell stack 12. Therefore, the resonance frequency of the cell stack 12 can be effectively increased.

[0082] Each of the pair of retaining parts 35A has an elastically deformable retaining plate 34. The retaining plate 34 is positioned between the cell laminate 12 and the damper member 51. The damper member 51 presses the retaining plate 34 toward the cell laminate 12. As a result, the damper member 51 and the retaining plate 34 apply a clamping load to the cell laminate 12, thereby effectively increasing the resonant frequency of the cell laminate 12.

[0083] The retaining plate 34 has a central portion 40 (pressing portion 41) and a plurality of arm portions 42 that extend radially from the central portion 40 in a direction perpendicular to the X direction. The damper member 51 presses the central portion 40 of the plate toward the cell laminate 12. This reduces the effect of vibrations in the arm portions 42 of the retaining plate 34, thereby effectively increasing the resonant frequency of the cell laminate 12.

[0084] The battery module 10B according to the second modified example will be described with reference to Figure 8. The battery module 10B according to the second modified example comprises a cell stack 12 and a holding mechanism 17B. The holding mechanism 17B comprises a plurality of battery frames 16 and a pair of holding parts 35B.

[0085] The holding mechanism 17B does not have a holding plate 34 (see Figure 6). Multiple connecting members 38 are connected to support members 56 of a pair of holding parts 35B. Damper members 51, each supported by the pair of support members 56, apply a tightening load to the cell laminate 12 via the pressure receiving plate 36. In this case, the desired tightening load can be adjusted by adjusting the tightness of the nuts 50 on the bolts 48. Alternatively, the multiple connecting members 38 may be fixed to the pair of support members 56 in a position that cannot be adjusted, and instead, the support members 56 may be fixed to the floor 110 in a position that can be adjusted.

[0086] The following additional information is disclosed regarding the above embodiments.

[0087] (Note 1) The battery modules (10, 10A, 10B) of the present disclosure include: a cell stack (12) having battery cells (18) and heat exchangers (20) stacked on the battery cells; a holding mechanism (17, 17A, 17B) having a pair of holding parts (35, 35A, 35B) that hold the cell stack by pressing both ends of the cell stack inward in the stacking direction (X) of the cell stack, and a connecting member (38) that connects the pair of holding parts to each other; and a detachment prevention mechanism (60) provided on the heat exchanger that prevents the heat exchanger from detaching from the cell stack by contacting the connecting member.

[0088] (Note 2) In the battery module described in Appendix 1, the detachment prevention mechanism may protrude from the peripheral edge of the heat exchanger in a direction (Y, Z) perpendicular to the stacking direction.

[0089] (Note 3) In the battery module described in Appendix 2, the detachment prevention mechanism may include an engaging claw (62) that can engage with the connecting member.

[0090] (Note 4) In the battery module described in Appendix 2, the detachment prevention mechanism may be provided with an insertion hole (68) through which the connecting member is inserted.

[0091] (Note 5) In the battery module described in any one of the appendices 2 to 4, the heat exchanger has a rectangular heat exchange plate (24), and the detachment prevention mechanism may be provided at the four corners of the heat exchange plate.

[0092] (Note 6) In the battery module described in Appendix 5, the detachment prevention mechanism may be provided in a pair of headers (25) located at both ends of the heat exchange plate.

[0093] (Note 7) In the battery module described in any one of the appendices 1 to 6, the portion of the detachment prevention mechanism that comes into contact with the connecting member may be subjected to a surface treatment to reduce the coefficient of friction.

[0094] (Note 8) In the battery module described in any one of the appendices 1 to 7, when the heat exchanger is not displaced in a direction intersecting the stacking direction, a gap exists between the connecting member and the detachment prevention mechanism, and the detachment prevention mechanism may come into contact with the connecting member as the heat exchanger is displaced in a direction intersecting the stacking direction.

[0095] (Note 9) In the battery module described in any one of the appendices 1 to 8, each of the pair of holding parts may have a damper member (51) that presses the cell stack in the stacking direction and a support member (56) that supports the damper member.

[0096] (Note 10) In the battery module described in Appendix 9, each of the pair of retaining parts further comprises an elastically deformable retaining plate (34), the retaining plate being positioned between the cell stack and the damper member, and the damper member pressing the retaining plate toward the cell stack.

[0097] (Note 11) In the battery module described in Appendix 10, the retaining plate has a pressing portion (41) and a plurality of arm portions (42) extending radially from the pressing portion in a direction perpendicular to the stacking direction, and the damper member may press the pressing portion toward the cell stack.

[0098] (Note 12) In the battery module described in Appendix 11, the pair of support members may be connected to each other by the connecting member.

[0099] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the spirit of this disclosure derived from the claims and their equivalents. Furthermore, these embodiments can be implemented in combination. For example, the order of operations and processes in the embodiments described above are shown as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above. [Explanation of Symbols]

[0100] 10, 10A, 10B… Battery Modules 12… Cell stack 17, 17A, 17B...holding mechanism 18…Battery cell 20...Heat exchanger 35, 35A, 35B...holding part 38…Connecting member 60... Detachment prevention mechanism

Claims

1. A cell stack comprising a battery cell and a heat exchanger stacked on the battery cell, A holding mechanism comprising: a pair of holding parts that hold the cell stack by pressing both ends of the cell stack inward in the stacking direction; and a connecting member that connects the pair of holding parts to each other; A detachment prevention mechanism is provided in the heat exchanger and prevents the heat exchanger from detaching from the cell laminate by contacting the connecting member, A battery module equipped with the following features.

2. In the battery module according to claim 1, The detachment prevention mechanism is a battery module that protrudes from the periphery of the heat exchanger in a direction perpendicular to the stacking direction.

3. In the battery module according to claim 2, The detachment prevention mechanism is a battery module equipped with an engaging claw that can engage with the connecting member.

4. In the battery module according to claim 2, The battery module is provided with an insertion hole through which the connecting member is inserted in the aforementioned detachment prevention mechanism.

5. In the battery module according to any one of claims 2 to 4, The heat exchanger has rectangular heat exchange plates, The aforementioned detachment prevention mechanism is a battery module provided at the four corners of the heat exchange plate.

6. In the battery module according to claim 5, The detachment prevention mechanism is provided in a battery module, each of which is located in a pair of headers provided at both ends of the heat exchange plate.

7. In the battery module according to any one of claims 1 to 4, A battery module in which the portion of the detachment prevention mechanism that comes into contact with the connecting member is subjected to a surface treatment to reduce the coefficient of friction.

8. In the battery module according to any one of claims 1 to 4, When no displacement of the heat exchanger occurs in a direction intersecting the stacking direction, a gap exists between the connecting member and the detachment prevention mechanism. A battery module in which the heat exchanger is displaced in a direction intersecting the stacking direction, causing the detachment prevention mechanism to come into contact with the connecting member.

9. In the battery module according to any one of claims 1 to 4, A battery module in which each of the pair of holding portions has a damper member that presses the cell stack in the stacking direction and a support member that supports the damper member.

10. In the battery module according to claim 9, Each of the pair of retaining parts further comprises an elastically deformable retaining plate, The retaining plate is positioned between the cell laminate and the damper member. The damper member presses the retaining plate toward the cell stack in the battery module.

11. In the battery module according to claim 10, The retaining plate has a pressing portion and a plurality of arm portions extending radially from the pressing portion in a direction perpendicular to the stacking direction, The damper member is a battery module that presses the pressing portion toward the cell stack.

12. In the battery module according to claim 11, A battery module in which a pair of support members are connected to each other by a connecting member.

Images