Inter-cell component unit, inter-cell component, battery unit

Abstract

The aim is to improve the balance between absorbing the expansion and contraction of multiple battery cells and protecting multiple battery cells from external forces. [Solution] The inter-cell member unit comprises a plurality of inter-cell members, each positioned between two adjacent battery cells in a cell stack, which comprises a plurality of battery cells arranged in one or more rows along a first direction on a predetermined plane. The inter-cell members extend along a second direction perpendicular to the first direction on the predetermined plane and protrude from the cell stack. The ends of the inter-cell members in the second direction abut or connect to a frame portion that is positioned on the outside of the cell stack in the second direction and extends along the first direction, or have a gap between them and the frame portion. The inter-cell members are provided with elastic beam portions that have elasticity that allows them to deform in accordance with the expansion and contraction of the battery cells in the first direction, and have higher strength than the frame portion in the second direction.

Description

Technical Field

[0001] The present disclosure relates to an inter-cell member unit, an inter-cell member, and a battery unit.

Background Art

[0002] Conventionally, a plurality of water-cooled plate assemblies each disposed between two adjacent battery cells in a predetermined direction in a cell stack, which is housed in a case together with a cell stack including a plurality of battery cells arranged in a plurality of rows along a predetermined direction, have been proposed (see Patent Document 1). Here, the water-cooled plate assembly includes a harmonica tube plate. An outer layer cooling passage and an inner layer cooling passage located inside the outer layer cooling passage are formed inside the harmonica tube plate, and the outer layer cooling passage and the inner layer cooling passage extend along the longitudinal direction of the harmonica tube plate (a direction orthogonal to the predetermined direction). One of the outer layer cooling passage and the inner layer cooling passage is a liquid-cooling cooling passage, and the other is filled with an elastic material. With such a configuration, the water-cooled plate assembly absorbs the expansion of the battery cells by the elastic material and cools the battery cells by a cooling medium flowing through the liquid-cooling cooling passage.

[0003] Furthermore, a reinforcing body has been proposed that is housed in a chamber formed by a lower case and an upper case together with a cell stack comprising multiple battery cells arranged in multiple rows along a predetermined direction, and is connected to the lower case and / or upper case (see Patent Document 2). Here, the reinforcing body comprises first and second members and first, second, and third beams. The first and second members are arranged on the outer side of one end of the cell stack in a predetermined direction, side by side in the width direction of the cell stack (a direction perpendicular to the predetermined direction). The first beam is arranged on the outer side of the other end of the cell stack in a predetermined direction and is formed to be approximately the same width as the cell stack. The second beam is arranged between two adjacent rows of the cell stack, extends along a predetermined direction, and is connected to the first member and the first beam. The third beam is arranged between two adjacent rows of the cell stack at a position different from the second beam, extends along a predetermined direction, and is connected to the second member and the first beam. Internal flow channels are formed in the first and second members and the first, second, and third beams, and a cooling channel for water cooling is formed by the communication of these internal flow channels in the first member, second beam, first beam, third beam, and second member. With this configuration, the reinforcing body improves the structural stability of the lower and upper cases and integrates the water cooling function into the reinforcing body. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Chinese Patent No. 114497826 Specification [Patent Document 2] Chinese Utility Model No. 216648494 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The water cooling plate assembly described in Patent Document 1 and the reinforcing body described in Patent Document 2 do not adequately achieve both the absorption of expansion and contraction of multiple battery cells and the protection of multiple battery cells from external forces outside the case, and there is a need to improve this balance.

[0006] The primary purpose of this disclosure is to improve the ability to both absorb the expansion and contraction of multiple battery cells and protect multiple battery cells from external forces. [Means for solving the problem]

[0007] This disclosure employs the following means to achieve the primary objectives described above.

[0008] The inter-cell member unit disclosed herein is A cell stack comprising a plurality of battery cells arranged in one or more rows along a first direction on a predetermined plane, wherein the cell stack comprises a plurality of inter-cell members each disposed between two adjacent battery cells in the first direction, The inter-cell member extends along a second direction perpendicular to the first direction on the predetermined plane and protrudes from the cell stack. The end of the intercell member in the second direction abuts against or connects to a frame portion located on the outside of the cell stack in the second direction and extending along the first direction, or has a gap between itself and the frame portion. The inter-cell member comprises an elastic beam portion that has elasticity that allows it to deform in accordance with the expansion and contraction of the battery cells in the first direction, and has higher strength in the second direction compared to the frame portion. This is the gist of it.

[0009] The inter-cell member unit of this disclosure, with the above-described configuration, can absorb the expansion and contraction of multiple battery cells through the elastic deformation of the elastic beam portion of the inter-cell member, and can also protect the multiple battery cells from the outside of the frame portion when an external force in a second direction is applied to the frame portion by the strength of the elastic beam portion (because the elastic beam portion is less likely to deform). In other words, it is possible to improve the balance between absorbing the expansion and contraction of multiple battery cells and protecting multiple battery cells from external forces. [Brief explanation of the drawing]

[0010] [Figure 1]This is a top-down perspective view of the battery unit of this disclosure. [Figure 2] This is a perspective view of Figure 1 with the top cover removed. [Figure 3] This is a perspective view of the battery unit from below. [Figure 4] This is a perspective view of Figure 3 with the bottom cover removed. [Figure 5] Figure 4 shows a perspective view with the case body and other components removed. [Figure 6] This is a perspective view of the cell stack. [Figure 7] This is a perspective view of the inter-cell component unit. [Figure 8] This is a perspective view of a portion of an inter-cell component unit. [Figure 9] Figure 8 is a side view from the right. [Figure 10] This is a side view of the intercellular member in a modified example. [Figure 11] This is a side view of the intercellular member in a modified example. [Figure 12] This is a side view of the intercellular member in a modified example. [Modes for carrying out the invention]

[0011] Embodiments for implementing the present disclosure will be described with reference to the drawings. FIG. 1 is an external perspective view of the battery unit 10 of the present disclosure from above. FIG. 2 is a perspective view of the state in which the upper cover 14 is removed from FIG. 1. FIG. 3 is an external perspective view of the battery unit 10 from below. FIG. 4 is a perspective view of the state in which the lower cover 15 is removed from FIG. 3. FIG. 5 is a perspective view of the state in which the case body 13 and the like are removed from FIG. 4. FIG. 6 is a perspective view of the cell stack 20. FIG. 7 is a perspective view of the inter-cell member unit 40. FIG. 8 is a partial perspective view of the inter-cell member unit 40. FIG. 9 is a side view from the right of FIG. 8. Note that the front-rear direction, left-right direction, and up-down direction of the battery unit 10 and the like are as shown in FIGS. 1 to 9. In the present disclosure, the front-rear direction corresponds to the "first direction", the left-right direction corresponds to the "second direction", and the plane extending along the front-rear direction and the left-right direction corresponds to the "predetermined plane". Hereinafter, the plane extending along the front-rear direction and the left-right direction may be referred to as the XY plane, the plane extending along the front-rear direction and the up-down direction may be referred to as the XZ plane, and the plane extending along the left-right direction and the up-down direction may be referred to as the YZ plane.

[0012] As shown in FIGS. 1 to 9, the battery unit 10 includes a case 12 and a cell stack unit 19 housed in the case 12. The cell stack unit 19 includes a cell stack 20, a restraint portion 30, and an inter-cell member unit 40.

[0013] As shown in FIGS. 1 to 5, the case 12 is generally in a substantially rectangular parallelepiped shape as a whole, and includes a case body 13, an upper cover 14, and a lower cover 15. The case body 13 is formed of, for example, an aluminum alloy or the like, and the upper cover 14 and the lower cover 15 are formed of, for example, a steel material (iron alloy) or the like.

[0014] The case body 13 is a short rectangular tube with openings at the upper and lower ends, and includes a front side wall portion 13a, a rear side wall portion 13b, a left side wall portion 13c, and a right side wall portion 13d. The upper cover 14 and the lower cover 15 are each plate-shaped. The upper cover 14 is fixed to the upper surface of the case body 13 using fastening members such as bolts, and closes the opening at the upper end of the case body 13. The lower cover 15 is fixed to the lower surface of the case body 13 using fastening members, and closes the opening at the lower end of the case body 13. The case body 13, the upper cover 14, and the lower cover 15 define a storage chamber 16 for housing the cell stack unit 19.

[0015] Mounting members 17, 18 are fixed to the lower end portions of the outer surfaces of the left side wall portion 13c and the right side wall portion 13d of the case body 13 using fastening members. The mounting members 17, 18 are formed of, for example, an aluminum alloy or the like, and are long rectangular tubes extending along the front-rear direction. The mounting members 17, 18 are fixed to, for example, the vehicle body of a vehicle using fastening members.

[0016] As shown in FIGS. 2, 4 to 6, the cell stack 20 includes a plurality of battery cells 21. Each battery cell 21 is configured as, for example, a lithium ion secondary battery or a nickel metal hydride secondary battery, and is substantially rectangular parallelepiped. The plurality of battery cells 21 are arranged in 4 columns (columns 22a to 22d in order from the left) along the front-rear direction on the XY plane. Note that it is not limited to 4 columns, and it may be 2 columns, 3 columns, or 5 or more columns.

[0017] Multiple battery cells 21 are connected in series as a whole. Specifically, two adjacent battery cells 21 in the front-to-back direction are electrically connected to each other via connection terminals 24 at the left or right end of their respective lower surfaces. As a result, multiple connection terminals 24 are arranged at intervals along the front-to-back direction at the left and right ends of each row 22a to 22d. The last two battery cells 21 of the left two rows 22a and 22b are electrically connected to each other via connection terminals 25 attached to the rear end plate 32 of the restraint section 30. The first two battery cells 21 of the central two rows 22b and 22c are electrically connected to each other via a connecting terminal 26. The last two battery cells 36 of the right two rows 22c and 22d are electrically connected to each other via a connecting terminal 27 attached to the rear end plate 32. The first two battery cells 21 of the left and right two rows 22a and 22d are made electrically connectable to the outside of the battery unit 10 via connection terminals (not shown). The connection relationships between the multiple battery cells 21 are not limited to these and can be designed as appropriate.

[0018] As shown in Figures 2, 4, and 5, the restraining portion 30 comprises a front end plate 31, a rear end plate 32, and a plurality of support portions 33. The front end plate 31, the rear end plate 32, and the plurality of support portions 33 are formed from, for example, an aluminum alloy.

[0019] The front end plate 31 is positioned in front of the cell stack 20 and is a rectangular parallelepiped that extends in the left-right and up-down directions. The rear end plate 32 is positioned behind the cell stack 20 and is a rectangular parallelepiped that extends in the left-right and up-down directions. Intercell members 41 of the intercell member unit 40 are positioned between two adjacent battery cells 21 in the front-rear direction in each row 22a to 22d, between the first battery cell 21 in each row 22a to 22d and the front end plate 31, and between the last battery cell 21 in each row 22a to 22d and the rear end plate 32. The lengths of the front end plate 31 and the rear end plate 32 in the left-right direction and the lengths of each intercell member 41 in the left-right direction are designed to be approximately the same, and they are designed to be slightly longer than the length of the cell stack 20 in the left-right direction. The front end plate 31 and the rear end plate 32 are fixed to the top cover 14 using fastening members. The upper surfaces of the multiple battery cells 21 and the upper surfaces of the multiple inter-cell members 41 are joined to the upper cover 14 using an adhesive or the like.

[0020] Each of the support portions 33 is positioned below the cell stack 20 and is a rectangular prism shape extending along the front-rear direction. The front ends of each of the support portions 33 are fixed to the lower surface of the front end plate 31 using fastening members, and the rear ends are fixed to the lower surface of the rear end plate 32 using fastening members. Each of the support portions 33 is in contact with the multiple connection terminals 34 in the left-right direction, or has a slight gap between itself and the multiple connection terminals 34. This restricts the left-right movement of the multiple battery cells 21.

[0021] As shown in Figures 2, 4, 5, and 7-9, the inter-cell member unit 40 comprises a plurality of inter-cell members 41 and a main flow path section 60. As described above, each inter-cell member 41 is positioned between two adjacent battery cells 21 in the front-to-back direction in each row 22a-22d, between the leading battery cell 21 of each row 22a-22d and the front end plate 31, and between the last battery cell 21 of each row 22a-22d and the rear end plate 32.

[0022] Each inter-cell member 41 comprises a housing section 42, first and second elastic beam sections 51 and 52, and a cap 54. The housing section 42 is made of a material having higher thermal conductivity than the first and second elastic beam sections 51 and 52, such as an aluminum alloy. The housing section 42 comprises a peripheral wall section 43 and a partition wall section 44. The peripheral wall section 43 is a long rectangular tube with a cross-section that is sufficiently long in the vertical direction compared to its length in the front-rear direction and extends along the left-right direction, and has a housing chamber 45 inside. The length of the peripheral wall section 43 in the left-right direction is designed to be slightly longer than the length of the cell stack 20 in the left-right direction. Multiple protrusions 48 are formed on the inner circumferential surfaces of the front and rear walls of the peripheral wall section 43 at intervals in the vertical direction. Each of the multiple protrusions 48 extends along the left-right direction.

[0023] The partition wall 44 extends along the left-right direction, connecting the center of the upper and lower walls of the peripheral wall 43 in the front-rear direction, and divides the storage chamber 45 into first and second storage chambers 46 and 47 arranged in the front-rear direction. Communication holes (not shown) are formed at the left-right ends of the partition wall 44. This allows the first storage chamber 46 and the second storage chamber 47 to communicate. The first and second storage chambers 46 and 47 are used as first and second branch flow paths for the cooling medium. The peripheral wall 43 and the partition wall 44 may be integrally molded, or they may be formed separately and joined by welding or the like.

[0024] The first and second elastic beam sections 51 and 52 are each made of a material having higher strength than the case body 13 and the housing section 42, such as steel (iron alloy). The first and second elastic beam sections 51 and 52 are each housed in the first and second housing chambers 46 and 47. The first and second elastic beam sections 51 and 52 each have a cross-section with a rounded "W" shape (constant shape) and extend linearly along the left-right direction. The first and second elastic beam sections 51 and 52 are arranged so that their ends and central parts in the vertical direction are close to each other, and they face each other in the front-rear direction. The contact points between the first and second elastic beam sections 51 and 52 and the projections 48 of the peripheral wall section 43 are joined by welding or the like. As a result, the vertical position of the first and second elastic beam sections 51 and 52 is fixed with respect to the first and second housing chambers 46 and 47. The lengths of the first and second elastic beam sections 51 and 52 in the left-right direction are designed to be approximately the same as the length of the peripheral wall section 43 in the left-right direction and slightly longer than the length of the cell stack 20 in the left-right direction. These first and second elastic beam sections 51 and 52 are elastically deformed by external forces in the front-rear direction and have high strength against external forces in the left-right direction.

[0025] Each cap 54 is formed from, for example, an aluminum alloy or steel (iron alloy). The cap 54 is a rectangular annular cross-section with a bottomed rectangular tube that is open at one end. Each cap 54 is attached to both ends of the corresponding peripheral wall portion 43 in the left-right direction, and the bottom of the cap 54 is fixed to the housing portion 42 and the first and second elastic beam portions 51, 52 in contact with each other by welding or the like. This closes both ends of the peripheral wall portion 43 (housing chamber 45) in the left-right direction. The thickness of the bottom of the cap 54 (length in the left-right direction) is designed to be stronger in the left-right direction compared to the left wall portion 13c and the right wall portion 13d of the case body 13. With caps 54 attached to both ends of the peripheral wall portion 43 in the left-right direction, the ends (caps 54) of the intercellular member 41 in the left-right direction may abut against the left wall portion 13c or the right wall portion 13d of the case body 13, or they may be joined to them by welding or the like, or there may be a slight gap between them.

[0026] Each inter-cell member 41 has two through holes (not shown) formed in its housing portion 42 (peripheral wall portion 43 and partition wall portion 44) and the first and second elastic beam portions 51 and 52, which are aligned vertically in the center in the left-right direction and penetrate in the front-rear direction.

[0027] The main flow path section 60 comprises a plurality of first and second pipe sections 61, 65, a plurality of first and second flexible sections 71, 72, and one supply pipe 73 and one discharge pipe 74, respectively. The first and second pipe sections 61, 65 each comprise a cylindrical section 62, 66, a flange section 63, 67, and a communication hole 64, 68. The cylindrical sections 62, 66 each have an annular cross-section and are cylindrical in shape, extending along the front-rear direction. The inside of the cylindrical sections 62, 66 is used as part of the main flow path for the cooling medium. The flange sections 63, 67 extend radially outward from the front of the center in the front-rear direction on the outer circumference of the cylindrical sections 62, 66. The first and second pipe sections 61 and 65 are inserted through two through holes formed in the corresponding housing section 42 (peripheral wall section 43 and partition wall section 44) and the first and second elastic beam sections 51 and 52, respectively, and are joined to the housing section 42 by welding or other means with the flange sections 63 and 67 in contact with the front surface of the housing section 42. The communication hole 64 is formed at a position where the inside of the first pipe section 61 and the first housing chamber 46 communicate when the first pipe section 61 is joined to the housing section 42. The communication hole 67 is formed at a position where the inside of the second pipe section 65 and the second housing chamber 47 communicate when the second pipe section 65 is joined to the housing section 42. Therefore, the inside of the first pipe section 61, the first housing chamber 46, the second housing chamber 47, and the inside of the second pipe section 65 communicate as a flow path for the cooling medium. The rear ends of the first and second pipe sections 61 and 65, which are joined to the rearmost inter-cell member 41 (housing section 42), are closed by, for example, a rear end plate 32.

[0028] The first and second flexible sections 71 and 72 are each formed from, for example, rubber or metal, and are bellows-shaped. One end of the first and second flexible sections 71 and 72 in the front-rear direction is joined by welding or the like to the first and second pipe sections 61 and 65, which are joined to the front housing section 42 of two adjacent housing sections 42 in the front-rear direction, and the other end is joined by welding or the like to the first and second pipe sections 61 and 65, which are joined to the rear housing section 42. By using the first flexible section 71 to connect the two first pipe sections 61, which are fixed to the two adjacent housing sections 42 in the front-rear direction, relative positional displacement of these two first pipe sections 61 in the left-right and up-down directions can be tolerated. Furthermore, by using the second flexible section 72 to connect two second pipe sections 65 that are fixed to two adjacent housing sections 42 in the front-rear direction, relative positional displacement of these two second pipe sections 65 in the left-right and up-down directions can be tolerated.

[0029] The supply pipe 73 and the discharge pipe 74 are each formed of, for example, an aluminum alloy, and are cylindrical with an annular cross-section extending along the front-to-back direction. The supply pipe 73 and the discharge pipe 74 are each inserted through through holes (not shown) formed in the front end plate 31 and joined by welding or the like to the first and second pipe sections 61 and 65, which are joined to the leading inter-cell member 41 (housing section 42), and to the front wall section 13a of the case body 13.

[0030] Multiple first and second pipe sections 61, 65 (cylindrical sections 62, 66), multiple first and second flexible sections 71, 72, the supply pipe 73, and the discharge pipe 74 are used as main flow paths for the cooling medium. With the above configuration, the cooling medium supplied into the supply pipe 73 is discharged to the outside via each first pipe section 61, each first flexible section 71, the housing section 42 (first housing chamber 46 and second housing chamber 47), each second pipe section 65, each second flexible section 72, and the discharge pipe 74. This allows multiple battery cells 21 to be cooled. Moreover, since the housing section 42 is formed of a material with high thermal conductivity, the multiple battery cells 21 can be cooled even more effectively.

[0031] In the battery unit 10 of this embodiment, the first and second elastic beams 51 and 52 of each inter-cell member 41 of the inter-cell member unit 40 each have a cross-section shaped like a "W" with rounded corners, extending linearly along the left-right direction and arranged to face each other in the front-rear direction. The second elastic beams 51 and 52 elastically deform from their initial state (the state in Figure 9) to a flat plate shape due to the force acting from the front-rear direction as the battery cells 21 on both sides expand in the front-rear direction. Furthermore, the second elastic beams 51 and 52 approach their initial state as the battery cells 21 contract after expansion. As a result, the expansion and contraction of the battery cells 21 can be absorbed by the deformation of the first and second elastic beams 51 and 52.

[0032] Furthermore, the first and second elastic beam sections 51 and 52 extend linearly along the left-right direction, and their length in the left-right direction is designed to be longer than the length of the cell stack 20 in the left-right direction. Therefore, the first and second elastic beam sections 51 and 52 protrude from the cell stack 20 in the left-right direction. As a result, when an external force in the left-right direction acts on the left wall section 13c and right wall section 13d of the case body 13 from outside the case 12, even if the left wall section 13c and right wall section 13d deform, the deformation of the first and second elastic beam sections 51 and 52 is suppressed. As a result, the cell stack 20 (multiple battery cells 21) can be protected. Moreover, caps 54 having a bottom with higher strength than the left wall section 13c and right wall section 13d of the case body 13 are attached to both ends of the housing section 42 (peripheral wall section 43) in the left-right direction. This also suppresses deformation of the first and second elastic beam sections 51, 52 and the cap 54, thereby providing better protection for the cell stack 20 (multiple battery cells 21).

[0033] In other words, an inter-cell member unit 40 comprising multiple inter-cell members 41 can improve the balance between absorbing the expansion and contraction of multiple battery cells 21 and protecting the cell stack 20 (multiple battery cells 21) from external forces.

[0034] Furthermore, in the battery unit 10, the main flow path of the cooling medium is composed of multiple first and second pipe sections 61, 65 (cylindrical sections 62, 66), multiple first and second flexible sections 71, 72, a supply pipe 73, and a discharge pipe 74, and extends along the front-rear direction between the two central rows 22b, 22c of the cell stack 20. In addition, the first and second branch flow paths of the cooling medium are formed as first and second housing chambers 46, 47 within the housing section 42. Furthermore, the lengths of the housing section 42 and the first and second elastic beam sections 51, 52 in the left-right direction are approximately the same, and caps 54 are attached to both ends of the housing section 42 (peripheral wall section 43) in the left-right direction. Therefore, as described above, deformation of the first and second elastic beam sections 51, 52 and the caps 54 is suppressed, thereby protecting the main flow path and the first and second branch flow paths.

[0035] In the embodiment described above, as shown in Figure 9, the inter-cell member 41 is provided with a housing section 42, but is not limited to this. For example, as shown in Figure 10, the inter-cell member 141 may include first and second housing sections 142A, 142B, a heat insulating section 149, and first and second elastic beam sections 51, 52. The first and second housing sections 142A, 142B are each rectangular annular shapes with a cross-section that is sufficiently long in the vertical direction compared to the length in the front-to-back direction and extends along the left-to-right direction, and have first and second housing chambers 146, 147 inside. The first and second housing sections 142A, 142B have protrusions 148A, 148B similar to the protrusions 48 described above. The first and second elastic beam sections 51, 52 described above are housed in the first and second housing chambers 146, 147. The contact points between the first and second elastic beam sections 51 and 52 and the protrusions 148A and 148B are joined by welding or the like. The heat insulating section 149 is made of, for example, inorganic fiber, foamed plastic, or aerogel, and is plate-shaped. The heat insulating section 149 is positioned between the first and second housing sections 142A and 142B in the front-rear direction and is joined to the first and second housing sections 142A and 142B by welding or the like. By providing the heat insulating section 149 in the inter-cell member 141, it is possible to suppress the influence of heat on one of two adjacent battery cells 21 in the front-rear direction when that cell becomes hot.

[0036] In the inter-cell member 141, the first and second housing chambers 146 and 147 may be used as first and second branch flow paths for the cooling medium, similar to the first and second housing chambers 46 and 47 of the inter-cell member 41. In this case, for example, it may be as follows: The first and second housing chambers 146 and 147 are connected to each other at their ends in the left-right direction via a cylindrical portion or the like. Furthermore, first and second through-holes are formed in the first and second housing sections 141 and 142, the heat insulating section 149, and the first and second beam sections 151 and 152, penetrating in the front-rear direction. Then, first and second pipe sections similar to the first and second pipe sections 61 and 65 are inserted into the first and second through-holes, respectively, and the inside of the first pipe section, the first housing chamber 146 (first branch flow path), the second housing chamber 147 (second branch flow path), and the inside of the second pipe section are connected as flow paths for the cooling medium.

[0037] In the embodiment described above, as shown in Figure 9, the housing chamber 45 within the peripheral wall portion 43 of the housing portion 42 of the intercellular member 41 is partitioned by a partition wall portion 44 into a first housing chamber 46 and a second housing chamber 47 arranged in the front-rear direction, but the embodiment is not limited to this. For example, as shown in Figures 11 and 12, the housing chambers 245 and 345 within the peripheral wall portions 243 and 343 of the intercellular members 241 and 341 may be partitioned by partition walls 244 and 344 into a first housing chamber 246 and 346 and a second housing chamber 247 and 347, respectively, arranged in the vertical direction. Multiple protrusions 248 and 348 are formed on the inner circumferential surfaces of the front and rear walls of the peripheral walls 243 and 343, respectively, with spacing in the vertical direction and extending along the left-right direction. In Figure 11, the first and second elastic beam sections 251 and 252 are housed in the first and second housing chambers 246 and 247, and in Figure 12, the first and second elastic beam sections 351 and 352 are housed in the first and second housing chambers 346 and 347, but the model is not limited to these. Details of the first and second elastic beam sections 251 and 252 will be described later. For example, the first and second housing chambers 246 and 247 or the first and second housing chambers 346 and 347 may house components with a shape similar to the first and second elastic beam sections 51 and 52.

[0038] In the inter-cell member 241, the first and second housing chambers 246 and 247 may be used as first and second branch flow paths for the cooling medium, similar to the first and second housing chambers 46 and 47 of the inter-cell member 41. In this case, for example, it may be as follows: The first and second housing chambers 246 and 247 communicate with each other, for example, through communication holes formed at the left and right ends of the partition wall portion 244. In addition, first through holes penetrating in the front-rear direction are formed in the circumferential wall portion 243 and the first elastic beam portion 251, and second through holes penetrating in the front-rear direction are formed in the circumferential wall portion 244 and the second elastic beam portion 252. Then, first and second pipe portions similar to the first and second pipe portions 61 and 65 are inserted into the first and second through holes, respectively, and the inside of the first pipe portion, the first housing chamber 246 (first branch flow path), the second housing chamber 247 (second branch flow path), and the inside of the second pipe portion communicate as flow paths for the cooling medium. The same applies to the intercellular member 341.

[0039] In the embodiment described above, as shown in Figure 9, the first and second elastic beam sections 51 and 52 have a cross-section with a rounded "W" shape and extend linearly along the left-right direction, but are not limited to this. For example, as shown in Figure 11, the first and second elastic beam sections 251 and 252 may have a rectangular annular cross-section and extend linearly along the left-right direction. In this case, the first and second elastic beam sections 251 and 252 may be housed in the first and second housing chambers 146 and 147 as shown in Figure 11, or in the first and second housing chambers 46 and 47 as shown in Figure 9. The contact portions between the first and second elastic beam sections 251 and 252 and the projection 248 or projection 48 are joined by welding or the like. Also, as shown in Figure 12, the first and second elastic beam sections 351 and 352 may have a cross-section that is deformed from a rectangular annular shape so that the front wall and rear wall alternately move apart and closer together, and extend linearly along the left-right direction. In this case, the first and second elastic beam sections 351 and 352 may be housed in the first and second housing chambers 346 and 347 as shown in Figure 12, or in the first and second housing chambers 46 and 47 as shown in Figure 9. The contact portions between the first and second elastic beam sections 351 and 352 and the projection 348 or projection 48 are joined by welding or the like. The cross-sectional shape of the first and second elastic beam sections is not limited to these shapes, and any shape is acceptable as long as it has elasticity that allows it to deform in accordance with the expansion and contraction of the battery cell 21 in the front-rear direction.

[0040] In the embodiment described above, the two first and second pipe sections 61 and 65, respectively joined to two adjacent housing sections 42 in the front-rear direction in the main flow channel section 60, are connected to each other using the first and second flexible sections 71 and 72, respectively. However, the embodiment is not limited to this. For example, the two first and second pipe sections 61 and 65, respectively joined to two adjacent housing sections 42 in the front-rear direction, may be directly connected to each other.

[0041] In the embodiment described above, the first and second housing chambers 46 and 47 of the intercell member 41 are used as first and second branch flow paths through which the cooling medium flows, but they do not have to be used as first and second branch flow paths. In this case, the intercell member unit 40 does not have two through holes formed in the housing portion 42 (peripheral wall portion 43 and partition wall portion 44) and the first and second elastic beam portions 51 and 52 of the intercell member 41, and does not have a main flow path portion 60. If the intercell member unit 40 does not have a main flow path portion 60, the multiple battery cells 21 may be arranged in a single row. Also, the housing portion 42 of the intercell member 41 may have one housing chamber 45 without a partition wall portion 44. Furthermore, the intercell member 41 does not have a cap 54. In addition, the intercell member 41 does not have a housing portion 42. In this case, it is preferable that a portion of the first and second elastic beam sections 51 and 52 are joined to the battery cell 21 by welding or the like, thereby restricting the displacement of the first and second elastic beam sections 51 and 52.

[0042] In the embodiment described above, the cell stack unit 19, which comprises the cell stack 20, the restraining portion 30, and the inter-cell member unit 40, is housed in the housing chamber 16 of the case 12, but is not limited to this. For example, instead of the cell stack unit 19 being housed in the case 12, a frame portion extending in the front-rear direction may be arranged on the outside of the cell stack unit 19 in the left-right direction. In this case, the caps 54 of each inter-cell member 41 of the inter-cell member unit 40 may abut the frame portion, be joined to the frame portion by welding or the like, or have a slight gap between them and the frame portion. The frame portion may be a component of the battery unit together with the cell stack unit 19, for example, a component corresponding to the mounting members 17 and 18 described above. Alternatively, the frame portion may be a separate component from the battery unit comprising the cell stack unit 19 and part of the vehicle on which the battery unit is mounted, for example, a so-called rocker EA material.

[0043] In the above-described embodiment, the form of the battery unit 10 was explained, but it may also be the form of an inter-cell member unit 40 used in the battery unit 10, or the form of an inter-cell member 41 used in the inter-cell member unit 40.

[0044] Furthermore, the correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem is merely an example to specifically explain the form in which the embodiment implements the invention described in the section on means for solving the problem, and does not limit the elements of the invention described in the section on means for solving the problem. In other words, the interpretation of the invention described in the section on means for solving the problem should be based on the description in that section, and the embodiment is merely one specific example of the invention described in the section on means for solving the problem.

[0045] Although the embodiments for implementing this disclosure have been described above, this disclosure is not limited in any way to these embodiments, and can of course be implemented in various forms without departing from the gist of this disclosure.

[0046] [Note] [1] The intercell member unit of the present disclosure comprises a plurality of intercell members, each disposed between two adjacent battery cells in a cell stack having a plurality of battery cells arranged in one or more rows along a first direction on a predetermined plane, wherein the intercell members extend along a second direction perpendicular to the first direction on the predetermined plane and protrude from the cell stack, and the end of the intercell member in the second direction abuts against or connects to a frame portion disposed on the outside of the cell stack in the second direction and extending along the first direction, or has a gap between itself and the frame portion, and the intercell member comprises an elastic beam portion that has elasticity that can be deformed in accordance with the expansion and contraction of the battery cells in the first direction and has higher strength than the frame portion in the second direction.

[0047] The inter-cell member unit of this disclosure, with the above-described configuration, can absorb the expansion and contraction of multiple battery cells through the elastic deformation of the elastic beam portion of the inter-cell member, and can also protect the multiple battery cells from the outside of the frame portion when an external force in a second direction is applied to the frame portion by the strength of the elastic beam portion (because the elastic beam portion is less likely to deform). In other words, it is possible to improve the balance between absorbing the expansion and contraction of multiple battery cells and protecting multiple battery cells from external forces.

[0048] [2] In the intercellular member unit of the present disclosure (the intercellular member unit described in [1] above), the elastic beam portion may have a constant cross-sectional shape and extend linearly along the second direction. This makes it possible to increase the strength of the elastic beam portion in the second direction.

[0049] [3] In the intercellular member unit of the present disclosure (the intercellular member unit described in [1] or [2] above), the elastic beam portion may be formed of a material with higher strength than the frame portion.

[0050] [4] In the intercellular member unit of the present disclosure (the intercellular member unit described in any one of [1] to [3] above), the intercellular member further comprises a housing portion having a housing chamber extending along the second direction, and the elastic beam portion may be housed in the housing chamber.

[0051] [5] In this case (the inter-cell member unit described in [4] above), the unit further comprises a main flow channel section having first and second main flow channels for a cooling medium extending along the first direction between two adjacent rows of the plurality of rows, wherein the housing chamber is divided into first and second housing chambers, the two elastic beam sections are housed in the first and second housing chambers respectively, the first housing chamber communicates with the first main flow channel, the second housing chamber communicates with the second main flow channel and the first housing chamber, and the first and second housing chambers may be used as first and second branch flow channels for the cooling medium. With this configuration, the cooling medium can be circulated from the first main flow channel through the first housing chamber and the second housing chamber to the second main flow channel to cool a plurality of battery cells.

[0052] [6] In this case (the inter-cell member unit described in [5] above), the elastic beam portion and the housing portion have first and second through holes that penetrate in the first direction, and the main flow channel portion may further include a first communication portion having a first communication hole that connects the first main flow channel and the first branch flow channel when inserted through the first through hole, and a second communication portion having a second communication hole that connects the second main flow channel and the second branch flow channel when inserted through the second through hole.

[0053] [7] In this case (the inter-cell member unit described in [6] above), two adjacent first connecting portions in the first direction may be connected using a first flexible portion, and two adjacent second connecting portions in the first direction may be connected using a second flexible portion. This allows for relative misalignment of the two adjacent first and second connecting portions in the first direction.

[0054] [8] In an inter-cell member unit of the present disclosure (an inter-cell member unit as described in any one of [5] to [7] above), the first and second housing chambers are used as first and second branch flow paths for a cooling medium, the housing portion may have higher thermal conductivity than the elastic beam portion, and the elastic beam portion may have higher strength in the second direction than the housing portion. This allows for better cooling of multiple battery cells.

[0055] [9] An intercell member unit of the present disclosure (an intercell member unit as described in any one of [4] to [8] above) comprising a housing portion having a housing chamber extending along a second direction, further comprising a cap attached to the end of the housing portion in the second direction, wherein the cap may have higher strength in the second direction than the frame portion. This provides better protection for multiple battery cells when an external force in the second direction acts on the frame portion from the outside.

[0056]

[10] In the inter-cell member unit of the present disclosure (the inter-cell member unit described in any one of [1] to [9] above), the inter-cell member may further include a heat insulating portion disposed between two elastic beam portions arranged side by side in the first direction. This makes it possible to suppress the effect of heat on one of two adjacent battery cells in the first direction when that cell becomes hot.

[0057]

[11] The intercell member of this disclosure is intended to be used in an intercell member unit described in any one of [1] to

[10] above. This provides effects similar to those of the intercell member unit described above, such as improving the ability to both absorb the expansion and contraction of multiple battery cells and protect multiple battery cells from external forces.

[0058]

[12] The first battery unit of the present disclosure comprises the inter-cell member unit described in any one of [1] to

[10] above, the cell stack, and the frame portion. This provides effects similar to those of the inter-cell member unit described above, such as improving the ability to both absorb the expansion and contraction of multiple battery cells and protect multiple battery cells from external forces.

[0059]

[13] The second battery unit of the present disclosure is a battery unit comprising the inter-cell member unit described in any one of [1] to

[10] above and the cell stack, and is mounted on a vehicle having the frame portion. This provides effects similar to those of the inter-cell member unit described above, for example, an improved balance between absorbing the expansion and contraction of multiple battery cells and protecting multiple battery cells from external forces. [Explanation of Symbols]

[0060] 10 Battery unit, 13 Case body, 20 Cell stack, 21 Battery cell, 40 Inter-cell member unit, 41, 141, 241, 341 Inter-cell members, 42, 242, 342 Housing section, 43, 243, 343 Peripheral wall section, 44, 244, 344 Partition wall section, 45, 245, 345 Housing chamber, 46, 146, 246, 346 First housing chamber, 47, 147, 247, 347 Second housing chamber, 51, 251, 351 First elastic beam section, 52, 252, 352 Second elastic beam section, 54 Cap, 60 Main flow path section, 61 First pipe section, 65 Second pipe section, 71 First flexible section, 72 Second flexible section, 142A First housing section, 143B Second housing section.

Claims

1. A cell stack comprising a plurality of battery cells arranged in one or more rows along a first direction on a predetermined plane, wherein the cell stack comprises a plurality of inter-cell members each disposed between two adjacent battery cells in the first direction, The inter-cell member extends along a second direction perpendicular to the first direction on the predetermined plane and protrudes from the cell stack. The end of the intercell member in the second direction is in contact with or connected to a frame portion that is located on the outside of the cell stack in the second direction and extends along the first direction, or has a gap between it and the frame portion. The inter-cell member comprises an elastic beam portion that has elasticity that allows it to deform in accordance with the expansion and contraction of the battery cells in the first direction, and has higher strength in the second direction compared to the frame portion. Intercellular component unit.

2. The intercellular member unit according to claim 1, The elastic beam portion has a constant cross-sectional shape and extends linearly along the second direction. Intercellular component unit.

3. An intercellular member unit according to claim 1 or 2, The elastic beam portion is formed from a material with higher strength than the frame portion. Intercellular component unit.

4. The intercellular member unit according to claim 1, The intercellular member further comprises a housing section having a housing chamber extending along the second direction, The elastic beam section is housed in the housing chamber. Intercellular component unit.

5. The intercellular member unit according to claim 4, The main channel section further comprises a first and second main channel for a cooling medium that extends along the first direction between two adjacent rows of the plurality of rows, The aforementioned containment chamber is divided into a first and a second containment chamber. The two elastic beam sections are housed in the first and second housing chambers, respectively. The first containment chamber is in communication with the first main flow path, The second containment chamber is in communication with the second main flow path and the first containment chamber. The first and second containment chambers are used as the first and second branch flow paths of the cooling medium. Intercellular component unit.

6. The intercellular member unit according to claim 5, The elastic beam portion and the housing portion are formed with first and second through holes that penetrate in the first direction. The main flow channel section further comprises a first communication section having a first communication hole that connects the first main flow channel and the first branch flow channel when inserted through the first through hole, and a second communication section having a second communication hole that connects the second main flow channel and the second branch flow channel when inserted through the second through hole. Intercellular component unit.

7. The intercellular member unit according to claim 6, Two adjacent first communication portions in the first direction are connected using a first flexible portion. Two adjacent second communication portions in the first direction are connected using a second flexible portion. Intercellular component unit.

8. The intercellular member unit according to claim 5, The housing portion has higher thermal conductivity than the elastic beam portion. The elastic beam portion has higher strength in the second direction compared to the housing portion. Intercellular component unit.

9. The intercellular member unit according to claim 4, The intercellular member further comprises a cap attached to the end of the housing portion in the second direction, The cap has higher strength in the second direction compared to the frame portion. Intercellular component unit.

10. The intercellular member unit according to claim 1, The intercellular member further comprises a heat insulating portion disposed between two of the elastic beam portions arranged side by side in the first direction. Intercellular component unit.

11. An intercellular member used in the intercellular member unit according to claim 1.

12. A battery unit comprising the inter-cell member unit according to claim 1, the cell stack, and the frame portion.

13. A battery unit comprising the inter-cell member unit according to claim 1 and the cell stack, The aforementioned frame section is mounted on a vehicle, Battery unit.

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