Battery cooler and battery unit

Abstract

To distribute the stress applied to the cooler when the battery cells expand. [Solution] A battery cooler positioned between two adjacent battery cells in a predetermined direction forms an internal space including a cooling channel and has an outer wall that can bend and deform in a predetermined direction. The outer wall has a first plate portion facing one battery cell and a second plate portion facing the other battery cell and facing the first plate portion across an internal space in a predetermined direction. The first plate portion and the second plate portion each have a first contact portion or a second contact portion that contacts the outer surface of the battery cell, and a first non-contact portion or a second non-contact portion that is continuous with the connection portion and forms a first gap or a second gap between itself and the battery cell that allows for the expansion and deformation of the battery cell, and is not in contact with the outer surface of the battery cell. Furthermore, the inner surface of the first non-contact portion of the first plate portion and the inner surface of the second non-contact portion of the second plate portion are not in contact with each other.

Description

Technical Field

[0001] The present invention relates to a cooler for a battery and a battery unit.

Background Art

[0002] Conventionally, a battery unit in which a plurality of battery cells are arranged side by side in a predetermined direction is known (see, for example, Patent Document 1). This battery unit includes a cooler disposed between two adjacent battery cells in a predetermined direction. The cooler has two plate portions that each extend in a planar shape, and the two plate portions are configured to face each other across an internal space in a predetermined direction. A cooling flow path through which a cooling fluid flows is formed in this internal space. According to the structure of this battery unit, it is possible to cool the battery cells by flowing the cooling fluid through the cooling flow path of the cooler.

[0003] In the above cooler, one of the two plate portions is in contact with the outer surface of the battery cell on one side in the predetermined direction, and the other plate portion is in contact with the outer surface of the battery cell on the other side in the predetermined direction. Each of these two plate portions is deformable by bending in the predetermined direction and can deform toward the internal space side in response to the expansion of the battery cell.

[0004] Further, the above cooler has an extension portion that extends in a predetermined direction in the internal space between the two plate portions. This extension portion is provided at both ends in the crossing direction that crosses the predetermined direction in which the two plate portions face each other. This extension portion has a function of suppressing the deformation of the plate portion against the input of vibration of the battery cell in the predetermined direction. And each plate portion is in contact with the outer surface of the corresponding battery cell over substantially the entire area in the crossing direction and is deformable by bending in the predetermined direction between the two extension portions.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, in the above-described cooler structure, the extended portion exists as a rigid body between the two plate portions. Therefore, when the battery cell expands, the stress associated with the expansion concentrates in the extended portion, and as a result, the extended portion may not be able to withstand the expansion force of the battery cell and undergo plastic deformation, or the reaction force restraint load from the cooler to the battery cell may become too high. If plastic deformation occurs in the extended portion, it becomes difficult for the plate portion to follow the shape as it flexes under repeated expansion and contraction of the battery cell. On the other hand, if the reaction force restraint load is too high, the battery cell may be damaged.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a battery cooler and battery unit that can make the cooler less susceptible to plastic deformation and less susceptible to damage to the battery cells by distributing the stress applied to the cooler when the battery cells expand. [Means for solving the problem]

[0008] One aspect of the present invention provides a battery cooler provided in a battery unit comprising two or more battery cells arranged side by side with a predetermined space between them in a predetermined direction, and a restraining member that restrains the relative movement of the battery cells in the predetermined direction, and which is provided in the predetermined space between two adjacent battery cells in the predetermined direction, having an outer wall that forms an internal space including a cooling channel through which a cooling fluid flows, and is flexible and deformable in the predetermined direction, the outer wall having a first plate portion facing one of the battery cells in the predetermined direction, and a second plate portion that faces the other battery cell in the predetermined direction and faces the first plate portion across the internal space in the predetermined direction The battery cooler comprises the following: the first plate portion has a first contact portion that contacts the outer surface of one of the battery cells, and a first non-contact portion that is continuous with the first contact portion, forms a first gap between itself and the one of the battery cells that allows for expansion and deformation of the one of the battery cells, and is not in contact with the outer surface of the one of the battery cells; and the second plate portion has a second contact portion that contacts the outer surface of the other of the battery cells, and a second non-contact portion that is continuous with the second contact portion, forms a second gap between itself and the other of the battery cells that allows for expansion and deformation of the other of the battery cells, and is not in contact with the outer surface of the other of the battery cells and is not in contact with the inner surface of the first non-contact portion.

[0009] Furthermore, one aspect of the present invention is a battery unit comprising: two or more battery cells arranged side by side with a predetermined space between them in a predetermined direction; a cooler disposed in the predetermined space between two adjacent battery cells in the predetermined direction; and a restraining member that restrains the relative movement of the battery cells in the predetermined direction, wherein the cooler has an outer wall that forms an internal space including a cooling channel through which a cooling fluid flows and is flexible in the predetermined direction, and the outer wall has a first plate portion facing one of the battery cells in the predetermined direction, and a second plate portion that faces the other battery cell in the predetermined direction and faces the first plate portion across the internal space in the predetermined direction. The battery unit comprises the first plate portion having a first contact portion that contacts the outer surface of one of the battery cells, and a first non-contact portion that is continuous with the first contact portion, forms a first gap between itself and the one of the battery cells that allows for expansion and deformation of the one of the battery cells, and is not in contact with the outer surface of the one of the battery cells, and the second plate portion having a second contact portion that contacts the outer surface of the other of the battery cells, and a second non-contact portion that is continuous with the second contact portion, forms a second gap between itself and the other of the battery cells that allows for expansion and deformation of the other of the battery cells, and is not in contact with the outer surface of the other of the battery cells and is not in contact with the inner surface of the first non-contact portion.

[0010] These configurations allow for the distribution of stress applied to the cooler when the battery cells expand, thereby making the cooler less susceptible to plastic deformation and less likely to damage the battery cells. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing a battery unit according to one embodiment of the present invention. [Figure 2] This is a diagram showing the configuration of the cooler included in the battery unit of this embodiment. [Figure 3] This is a cross-sectional view of the cooler of this embodiment when cut along the line III-III shown in Figure 2. [Figure 4] This is an enlarged cross-sectional view of the main part of the cooler of this embodiment. [Figure 5] This is a diagram illustrating the function of the cooler in this embodiment. [Modes for carrying out the invention]

[0012] Specific embodiments of the battery unit and battery cooler according to the present invention will be described below with reference to Figures 1 to 5.

[0013] One embodiment of the battery unit 10, as shown in Figure 1, is a unit that functions, for example, as a traction battery for a vehicle. The vehicle on which the battery unit 10 is installed is an electric vehicle or a plug-in hybrid vehicle.

[0014] The battery unit 10 is, for example, a lithium-ion battery or a nickel-metal hydride battery. As shown in Figure 1, the battery unit 10 comprises a battery cell 20, a cooler 30, and a restraining member 60.

[0015] The battery cell 20 is a cell that makes up a battery. The battery cell 20 may be a single cell or part of a single cell that makes up a stacked battery. The battery cell 20 may be a cell that makes up a monopolar battery or a cell that makes up a bipolar battery. The battery cell 20 is a rechargeable battery that can be repeatedly charged and discharged. The battery cell 20 is formed, for example, in a prismatic shape.

[0016] The battery unit 10 is composed of two or more battery cells 20. That is, there are two or more battery cells 20 in the battery unit 10. The two or more battery cells 20 are arranged side by side with a predetermined space 21 between them in a predetermined direction X. The two or more battery cells 20 are electrically connected to each other in series or in parallel.

[0017] As shown in Figure 1, the battery cell 20 is restrained in a predetermined direction X by a restraining member 60. That is, the restraining member 60 is a member that restrains the relative movement of the battery cells 20 in the predetermined direction X. The restraining member 60 is composed of case members 61 and 62 that are formed in the shape of a plate or corner and extend in the predetermined direction X. The case members 61 and 62 are arranged to sandwich the battery cell 20 in the intersecting direction Y (specifically, the orthogonal direction) that intersects the predetermined direction X. The battery cell 20 is restrained by joining some of its surfaces (the top and bottom surfaces in Figure 1) to the case members 61 and 62 with an adhesive or the like.

[0018] The cooler 30 is a battery cooler that cools the battery cells 20. The cooler 30 suppresses the temperature rise of the battery cells 20 by circulating a cooling fluid and exchanging heat between the cooling fluid and the battery cells 20. As shown in Figure 2, the cooler 30 is a plate-shaped member having a cooling channel 31 through which the cooling fluid flows. The cooler 30 is placed in a predetermined space 21 between two adjacent battery cells 20 in a predetermined direction X. A cooler 30 is provided for each predetermined space 21 between two adjacent battery cells 20 in a predetermined direction X. It is preferable that each cooler 30 is restrained or fixed to the restraining member 60 or the battery cell 20 to prevent it from coming out of the predetermined space 21.

[0019] The cooler 30 has an outer wall 32, as shown in Figure 2. The outer wall 32 is a wall member that extends in a plate-like shape. The outer wall 32 surrounds the cooling channel 31 and forms an internal space 33 that includes the cooling channel 31. The cooling channel 31 may be part of the entire internal space 33 or it may be all of it. The outer wall 32 is made of a metal material such as aluminum. The outer wall 32 is provided with an inlet and an outlet that connect to the cooling channel 31.

[0020] The outer wall 32 extends so as to include a surface containing two directions orthogonal to the predetermined direction X. The outer wall 32 has a predetermined thickness. This predetermined thickness is set, for example, within the range of 0.5 mm to 2.0 mm. The outer wall 32 is formed such that its thickness is substantially uniform over the entire area of the outer wall 32. The outer wall 32 is capable of flexurally deforming in the predetermined direction X in which the battery cells 20 are arranged side by side. However, it is preferable that the thickness of the outer wall 32 be as small as possible in order to disperse the stress applied from the outside (specifically, the battery cells 20).

[0021] As shown in FIG. 3, the outer wall 32 has a first plate portion 40 and a second plate portion 50.

[0022] The first plate portion 40 is a plate portion that faces one of the two battery cells 20 forming the predetermined space 21 in which the cooler 30 is arranged, in the predetermined direction X. The second plate portion 50 is a plate portion that faces the other of the two battery cells 20 forming the predetermined space 21 in which the cooler 30 is arranged, in the predetermined direction X. Hereinafter, for the sake of convenience, one of the battery cells 20 on one side (the left side in FIG. 3) with respect to a specific cooler 30 is referred to as the one-side battery cell 20L, and the other of the battery cells 20 on the other side (the right side in FIG. 3) with respect to that specific cooler 30 is referred to as the other-side battery cell 20R.

[0023] The first plate portion 40 and the second plate portion 50 are connected to each other and integrated with each other at both ends in the intersecting direction Y that intersects the predetermined direction X. The first plate portion 40 can contact the one-side battery cell 20L and elastically deform due to the pressing force accompanying the expansion of the one-side battery cell 20L. The second plate portion 50 can contact the other-side battery cell 20R and elastically deform due to the pressing force accompanying the expansion of the other-side battery cell 20R.

[0024] The first plate portion 40 and the second plate portion 50 face each other in a predetermined direction X, separated by an internal space 33. The first plate portion 40 and the second plate portion 50 are arranged so that they do not come into contact with each other even when one battery cell 20L and the other battery cell 20R are at their maximum expansion. In other words, the size of the internal space 33 between the first plate portion 40 and the second plate portion 50 is set so that the plate portions 40 and 50 do not come into contact with each other even when one battery cell 20L and the other battery cell 20R are at their maximum expansion.

[0025] The first plate portion 40 has a first contact portion 41 and a first non-contact portion 42. The first contact portion 41 is the portion that contacts the outer surface of the other battery cell 20R side of the one battery cell 20L. The first contact portion 41 is formed in a flat plate shape and extends parallel to the outer surface of the one battery cell 20L. The first contact portion 41 is located on the central side of the first plate portion 40 in the intersecting direction Y.

[0026] The first non-contact portion 42 is a part of the battery cell 20L that is not in contact with the outer surface of the other battery cell 20R. The first non-contact portion 42 is formed continuously with the first contact portion 41. The first non-contact portion 42 is formed such that the ratio of the length in the intersecting direction Y of the first plate portion 40 is 10% to 30% of the length of the entire first plate portion 40. The length in the intersecting direction Y of the first non-contact portion 42 (or, if the first non-contact portion 42 is provided in two separate locations as described later, the sum of the lengths of the two first non-contact portions 42) is set to, for example, 10 mm to 20 mm.

[0027] The first non-contact portion 42 is positioned and formed so that it does not come into contact with the outer surface of the one-side battery cell 20L even when the one-side battery cell 20L is at its maximum expansion. A first gap 43 is formed between the first non-contact portion 42 and the one-side battery cell 20L, which allows for the expansion deformation of the one-side battery cell 20L. The first gap 43 is set so that the first non-contact portion 42 and the one-side battery cell 20L do not come into contact with each other even when the one-side battery cell 20L is at its maximum expansion.

[0028] The first non-contact portion 42 is provided on both ends of the first plate portion 40 in the intersecting direction Y. The first non-contact portion 42 is provided in two locations on the first plate portion 40, separated in the intersecting direction Y. Hereinafter, the first non-contact portion 42 on one end side of the intersecting direction Y (upper side in Figures 1 and 3) will be referred to as the first non-contact portion 42U, and the first non-contact portion 42 on the other end side of the intersecting direction Y (lower side in Figures 1 and 3) will be referred to as the first non-contact portion 42D. The first non-contact portion 42U and the first non-contact portion 42D are arranged apart from each other in the intersecting direction Y, with the first contact portion 41 in between. The first non-contact portion 42U and the first non-contact portion 42D are arranged symmetrically with respect to the first contact portion 41.

[0029] The second plate portion 50 has a second contact portion 51 and a second non-contact portion 52. The second contact portion 51 is the portion that contacts the outer surface of the other battery cell 20R on the side of the one battery cell 20L. The second contact portion 51 is formed in a flat plate shape and extends parallel to the outer surface of the other battery cell 20R. The second contact portion 51 is located on the central side of the second plate portion 50 in the intersecting direction Y.

[0030] The second non-contact portion 52 is a part of the other battery cell 20R that is not in contact with the outer surface of the one battery cell 20L. The second non-contact portion 52 is formed continuously with the second contact portion 51. The second non-contact portion 52 is formed such that the ratio of the length in the intersecting direction Y of the second plate portion 50 is 10% to 30% of the length of the entire second plate portion 50. The length in the intersecting direction Y of the second non-contact portion 52 (or, if the second non-contact portion 52 is provided in two separate locations as described later, the sum of the lengths of the two second non-contact portions 52) is set to, for example, 10 mm to 20 mm.

[0031] The second non-contact portion 52 is positioned and formed so that it does not come into contact with the outer surface of the other battery cell 20R even when the other battery cell 20R is at its maximum expansion. A second gap 53 is formed between the second non-contact portion 52 and the other battery cell 20R, which allows for the expansion deformation of the other battery cell 20R. The second gap 53 is set so that the second non-contact portion 52 and the other battery cell 20R do not come into contact with each other even when the other battery cell 20R is at its maximum expansion.

[0032] The second non-contact portion 52 is provided on both ends of the second plate portion 50 in the intersecting direction Y. The second non-contact portion 52 is provided in two locations on the second plate portion 50, separated in the intersecting direction Y. Hereinafter, the second non-contact portion 52 on one end side of the intersecting direction Y (upper side in Figures 1 and 3) will be referred to as the one-end second non-contact portion 52U, and the second non-contact portion 52 on the other end side of the intersecting direction Y (lower side in Figures 1 and 3) will be referred to as the other-end second non-contact portion 52D. The one-end second non-contact portion 52U and the other-end second non-contact portion 52D are arranged apart from each other in the intersecting direction Y, with the second contact portion 51 in between. The one-end second non-contact portion 52U and the other-end second non-contact portion 52D are arranged symmetrically with respect to the second contact portion 51.

[0033] One end of the first non-contact portion 42U on one end of the first plate portion 40 in the intersecting direction Y and one end of the second non-contact portion 52U on one end of the second plate portion 50 in the intersecting direction Y are connected to each other and integrated. The first non-contact portion 42U on one end and the second non-contact portion 52U on one end are not connected to each other except at one end in the intersecting direction Y, and their inner surfaces face each other with a gap (size W in Figure 4) between them. One end of the first non-contact portion 42D on the other end of the first plate portion 40 in the intersecting direction Y and one end of the second non-contact portion 52D on the other end of the second plate portion 50 in the intersecting direction Y are connected to each other and integrated. The first non-contact portion 42D on the other end and the second non-contact portion 52D on the other end are not connected to each other except at the other end in the intersecting direction Y, and their inner surfaces face each other with a gap (size W in Figure 4) between them.

[0034] The first non-contact portion 42U at one end and the first non-contact portion 42D at the other end are each formed in an arc shape so as to be able to flex and deform in a predetermined direction X from the boundary point connected to the first contact portion 41 to the tip point in the intersecting direction Y. Similarly, the second non-contact portion 52U at one end and the second non-contact portion 52D at the other end are each formed in an arc shape so as to be able to flex and deform in a predetermined direction X from the boundary point connected to the second contact portion 51 to the tip point in the intersecting direction Y.

[0035] The first gap 43 and the second gap 53 described above are configured such that their size S changes smoothly according to the position in the intersecting direction Y. Specifically, the size S of the first gap 43 is set to gradually increase from zero from the boundary point between the first non-contact portion 42 and the first contact portion 41 to the tip point in the intersecting direction Y, then gradually decrease, and then gradually increase again. Similarly, the size S of the second gap 53 is set to gradually increase from zero from the boundary point between the second non-contact portion 52 and the second contact portion 51 to the tip point in the intersecting direction Y, then gradually decrease, and then gradually increase again.

[0036] The first non-contact portion 42U and the second non-contact portion 52U on one end are formed to curve and extend from the boundary point connected to the first contact portion 41 or the second contact portion 51 to the tip of one end in the intersecting direction Y, with the separation distance in a predetermined direction X changing sequentially from large to small to large, and are connected to each other at one end in the intersecting direction Y. Similarly, the first non-contact portion 42D and the second non-contact portion 52D on the other end are formed to curve and extend from the boundary point connected to the first contact portion 41 or the second contact portion 51 to the tip of the other end in the intersecting direction Y, with the separation distance in a predetermined direction X changing sequentially from large to small to large, and are connected to each other at the other end in the intersecting direction Y.

[0037] The cooler 30 has an elastic body 35. The elastic body 35 is a member that can be elastically deformed in a predetermined direction X. The elastic body 35 is made of a rubber material such as polyurethane. The elastic body 35 is arranged in the internal space 33 and is interposed between the inner surface of the first contact portion 41 facing the internal space 33 and the inner surface of the second contact portion 51 facing the internal space 33. The elastic body 35 is formed in the shape of a thin plate that extends in the predetermined direction X and in the depth direction Z which is perpendicular to both the predetermined direction X and the intersecting direction Y.

[0038] When the first plate portion 40 and the second plate portion 50 are pressed inward in a predetermined direction X toward the internal space 33 due to the expansion of the battery cell 20, the elastic body 35 contracts in the predetermined direction X, thereby applying a reaction force to the first plate portion 40 and the second plate portion 50. The elastic body 35 returns to its original state when the above-mentioned pressing force is removed.

[0039] The elastic bodies 35 are arranged at multiple locations (five locations in Figure 3) separated in the intersecting direction Y within the internal space 33. Elastic bodies 35 adjacent to each other in the intersecting direction Y are arranged at a predetermined distance apart so that cooling channels 31 through which cooling fluid flows are formed. The multiple elastic bodies 35 divide the internal space 33 into multiple spaces so that multiple cooling channels 31 (four in Figure 3) are formed. In other words, the cooling channels 31 are partitioned within the internal space 33 by the multiple elastic bodies 35. These multiple cooling channels 31 only need to be connected to each other at any point in the depth direction Z.

[0040] As shown in Figure 3, projections 41a are provided on the inner surface of the first contact portion 41. The projections 41a are provided at multiple locations separated in the intersecting direction Y. Similarly, projections 51a are provided on the inner surface of the second contact portion 51. The projections 51a are provided at multiple locations separated in the intersecting direction Y. Each projection 51a is positioned corresponding to the projections 41a described above. The projections 41a and 51a each protrude inward from the inner surface of the first contact portion 41 or the second contact portion 51 toward the internal space 33 in a predetermined direction X. The projections 41a and 51a each extend in the depth direction Z.

[0041] Each elastic body 35 is attached to a projection 41a of the first contact portion 41 and to a projection 51a of the second contact portion 51. Each elastic body 35 has grooves 35a and 35b. The grooves 35a and 35b are formed on the surface of the elastic body 35 that is exposed outward in a predetermined direction X. The groove 35a is formed corresponding to the projection 41a. The groove 35b is formed corresponding to the projection 51a. When assembling the cooler 30, the elastic bodies 35 are inserted into the internal space 33 from the outside in the depth direction Z such that the grooves 35a and 35b fit onto the projections 41a and 51a.

[0042] Furthermore, instead of attaching each elastic body 35 to the projection 41a of the first contact portion 41 and the projection 51a of the second contact portion 51 as described above, they may be attached to the inner surface of the first contact portion 41 and the inner surface of the second contact portion 51 using an adhesive or the like.

[0043] In the battery unit 10 described above, the cooler 30 is positioned in a predetermined space 21 between two adjacent battery cells 20 in a predetermined direction X. In this cooler 30, the outer wall 32 that forms the internal space 33 including the cooling channel 31 has a first plate portion 40 and a second plate portion 50 that face each other in a predetermined direction X. The first plate portion 40 and the second plate portion 50 each have a first contact portion 41 or a second contact portion 51 that is in contact with the outer surface of the battery cell 20, and a first non-contact portion 42 or a second non-contact portion 52 that is continuous with the first contact portion 41 or the second contact portion 51.

[0044] Unlike the first contact portion 41 and the second contact portion 51, the first non-contact portion 42 and the second non-contact portion 52 each form a first gap 43 or a second gap 53 between themselves and the battery cell 20 that allows for expansion and deformation of the battery cell 20, and are not in contact with the outer surface of the battery cell 20. Furthermore, the first non-contact portion 42 and the second non-contact portion 52 are connected to each other at both ends in the intersecting direction Y, but are not connected to each other at other points in the intersecting direction Y, and their inner surfaces face each other with a gap between them and are not in contact with each other.

[0045] In this configuration of the battery unit 10, each battery cell 20 is in contact with either the first contact portion 41 of the first plate portion 40 or the second contact portion 51 of the second plate portion 50, which form the outer wall 32 of the cooler 30. The outer wall 32 of the cooler 30 forms an internal space 33 including a cooling channel 31. When cooling fluid flows through the cooling channel 31, cold air is transmitted from the cooling fluid to the outer surface of the battery cell 20 through the outer wall 32 of the cooler 30. Therefore, when the battery cell 20 becomes hot due to charging or other reasons, the cooler 30 can cool the battery cell 20.

[0046] Furthermore, in the configuration of the battery unit 10, when the battery cell 20 expands outward in a predetermined direction X due to charging of the battery unit 10, the outer surface of the battery cell 20 presses the first contact portion 41 or the second contact portion 51 of the cooler 30 toward the internal space 33 in the predetermined direction X. When such pressing force acts on the first contact portion 41 or the second contact portion 51, the cooler 30 is sandwiched between the two battery cells 20 on both sides in the predetermined direction X, and the outer wall 32 deforms by bending in the predetermined direction X. As shown in Figure 5, this bending deformation of the outer wall 32 occurs such that the first contact portion 41 and the second contact portion 51 are in contact with the outer surface of the battery cell 20, while the first non-contact portion 42 and the second non-contact portion 52 do not come into contact with each other and do not come into contact with the outer surface of the battery cell 20, thereby absorbing the pressing force from the battery cell 20.

[0047] In this configuration, the cooler 30 does not exist as a rigid body between the two battery cells 20, so stress associated with the expansion of the battery cells 20 does not concentrate in the cooler 30, and the stress is distributed. Therefore, it is possible to suppress plastic deformation in the cooler 30 due to stress concentration, and thus ensure the shape-following ability of the outer wall 32 in the event of repeated expansion and contraction of the battery cells 20, and prevent the outer wall 32 from becoming difficult to follow the shape due to plastic deformation of the cooler 30. In addition, since the reaction force restraining load from the cooler 30 to the battery cells 20 during expansion can be kept low, the battery cells 20 can be made less susceptible to damage.

[0048] Therefore, according to this embodiment, the stress applied to the cooler 30 when the battery cell 20 expands can be distributed, thereby making the cooler 30 less susceptible to plastic deformation and less susceptible to damage to the battery cell 20.

[0049] Furthermore, in the configuration of the battery unit 10, the cooler 30 has an elastic body 35 interposed between the inner surface of the first plate portion 40 and the inner surface of the second plate portion 50 of the outer wall 32. The elastic body 35 can be elastically deformed in a predetermined direction X. With this configuration, when the outer wall 32 of the cooler 30 bends and deforms in a predetermined direction X due to the expansion of the battery cell 20, the elastic body 35 applies an elastic force as a reaction force from the cooler 30 to the battery cell 20 in opposition to the pressing force associated with the expansion of the battery cell 20, thereby preventing the cooler 30 from collapsing in opposition to the expansion of the battery cell 20.

[0050] Furthermore, in the configuration of the cooler 30, the elastic body 35 divides the internal space 33 into multiple cooling channels 31 through which the cooling fluid flows. The cooling channels 31 are partitioned by multiple elastic bodies 35 within the internal space 33. Therefore, the elastic body 35 can function as a means of generating a reaction force against the expansion of the battery cell 20, as well as as a partition plate that divides the cooling channels 31, thereby enabling effective utilization of the elastic body 35 and reducing costs.

[0051] In the above embodiment, the outer wall 32 of the cooler 30 is formed so that its thickness is substantially uniform throughout the entire surface of the outer wall 32 (for example, 0.5 mm to 2.0 mm). However, the present invention is not limited thereto, and the thickness of the outer wall 32 may be non-uniform throughout its entire surface. For example, the thickness of the first non-contact portion 42 of the outer wall 32 may be smaller than the thickness of the first contact portion 41, and the thickness of the second non-contact portion 52 may be smaller than the thickness of the second contact portion 51. With this modified configuration, the first contact portion 41 of the first plate portion 40 and the second contact portion 51 of the second plate portion 50 can be prevented from bending too much due to the pressing force accompanying the expansion of the battery cell 20, while the stress applied from the battery cell 20 can be distributed in the first non-contact portion 42 and the second non-contact portion 52.

[0052] Furthermore, in the above embodiment, in order to interpose the elastic body 35 of the cooler 30 between the first plate portion 40 and the second plate portion 50, protrusions 41a, 51a are provided on the inner surface of the first contact portion 41 and the inner surface of the second contact portion 51, respectively, and grooves 35a, 35b are provided on the elastic body 35. However, the present invention is not limited thereto, and when sufficient thickness can be secured for the first plate portion 40 and the second plate portion 50, grooves may be provided on the inner surface of the first contact portion 41 and the inner surface of the second contact portion 51, respectively, and protrusions may be provided on the elastic body 35.

[0053] Furthermore, the present invention is not limited to the embodiments and modifications described above, and various modifications can be made without departing from the spirit of the invention. In addition, this specification not only discloses the technical concept indicated by the reference relationships described in each claim at the time of filing, but also discloses a technical concept that appropriately combines the matters described in each claim. [Explanation of symbols]

[0054] 10: Battery unit, 20: Battery cell, 20L: One-side battery cell, 20R: Other-side battery cell, 21: Determined space, 30: Cooler (battery cooler), 31: Cooling channel, 32: Outer wall, 33: Internal space, 35: Elastic body, 35a, 35b: Groove, 40: First plate portion, 41: First contact portion, 41a: Protrusion, 42: First non-contact portion, 42U: First non-contact portion on one end, 42D: First non-contact portion on the other end, 43: First gap, 50: Second plate portion, 51: Second contact portion, 51a: Protrusion, 52: Second non-contact portion, 52U: Second non-contact portion on one end, 52D: Second non-contact portion on the other end, 53: Second gap, 60: Restraining member, X: Determined direction, Y: Intersecting direction, Z: Depth direction.

Claims

1. A battery cooler is provided in a battery unit comprising two or more battery cells arranged side by side with a predetermined space between them in a predetermined direction, and a restraining member that restrains the relative movement of the battery cells in the predetermined direction, and is positioned in the predetermined space between two adjacent battery cells in the predetermined direction, It has an outer wall that can be flexibly deformed in the predetermined direction, forming an internal space including a cooling channel through which a cooling fluid flows, The aforementioned exterior wall is One of the battery cells has a first plate portion facing it in the predetermined direction, The other battery cell is opposed to the first plate portion in the predetermined direction, and the second plate portion is opposed to the first plate portion across the internal space in the predetermined direction, It has, The first plate portion is, A first contact portion that contacts the outer surface of one of the battery cells, A first non-contact portion is provided which is continuous with the first contact portion and forms a first gap between it and the one battery cell that allows for expansion and deformation of the one battery cell, and which is not in contact with the outer surface of the one battery cell. It has, The second plate portion is, The other second contact portion that contacts the outer surface of the battery cell, The second non-contact portion is continuous with the second contact portion and forms a second gap between it and the other battery cell that allows for expansion and deformation of the other battery cell, and is not in contact with the outer surface of the other battery cell and is not in contact with the inner surface of the first non-contact portion, A battery cooler having the following features.

2. The first contact portion is provided on the center side of the intersecting direction that intersects the predetermined direction in the first plate portion, The first non-contact portion is provided on both ends of the first plate portion in the intersecting direction and includes a one-end first non-contact portion that is continuous with respect to the first contact portion on one end in the intersecting direction, and a other-end first non-contact portion that is continuous with respect to the first contact portion on the other end in the intersecting direction. The second contact portion is provided on the center side in the intersecting direction of the second plate portion, The second non-contact portion is provided on both ends of the second plate portion in the intersecting direction and includes a one-end second non-contact portion that is continuous with respect to the second contact portion on one end in the intersecting direction, and a other-end second non-contact portion that is continuous with respect to the second contact portion on the other end in the intersecting direction. The one end of the first non-contact portion on one end side in the intersecting direction and the one end of the second non-contact portion on one end side in the intersecting direction are connected to each other. The battery cooler according to claim 1, wherein the other end in the intersecting direction of the first non-contact portion on the other end and the other end in the intersecting direction of the second non-contact portion on the other end are connected to each other.

3. The battery cooler according to claim 2, wherein the first non-contact portion on one end, the first non-contact portion on the other end, the second non-contact portion on one end, and the second non-contact portion on the other end are each formed in an arc shape so as to be able to flex and deform in the predetermined direction from the boundary portion connected to the first contact portion or the second contact portion to the tip portion in the intersecting direction.

4. The first non-contact portion on one end and the second non-contact portion on one end are formed to curve and extend from the boundary point connected to the first contact portion or the second contact portion to the tip point on one end in the intersecting direction, with the separation distance in the predetermined direction changing sequentially from large to small to large, and to connect with each other at one end in the intersecting direction. The battery cooler according to claim 2, wherein the first non-contact portion on the other end and the second non-contact portion on the other end are formed to curve and extend from a boundary point connected to the first contact portion or the second contact portion to the tip of the other end in the intersecting direction, with the separation distance in the predetermined direction changing sequentially from large to small to large, and are connected to each other at the other end in the intersecting direction.

5. A battery cooler according to claim 1, having an elastic body interposed between the inner surface of the first contact portion and the inner surface of the second contact portion, which can be elastically deformed in the predetermined direction.

6. The battery cooler according to claim 5, wherein the elastic body is arranged at multiple locations in the internal space that are separated in intersecting directions that intersect in the predetermined direction.

7. The battery cooler according to claim 6, wherein the cooling channel is partitioned by the plurality of elastic bodies in the internal space.

8. The battery cooler according to claim 5, wherein the elastic body is attached to projections that protrude in a predetermined direction from the inner surface of the first contact portion and the inner surface of the second contact portion, respectively.

9. The thickness of the first non-contact portion is smaller than the thickness of the first contact portion. A battery cooler according to any one of claims 1 to 8, wherein the thickness of the second non-contact portion is smaller than the thickness of the second contact portion.

10. A battery unit comprising: two or more battery cells arranged side by side with a predetermined space between them in a predetermined direction; a cooler positioned in the predetermined space between two adjacent battery cells in the predetermined direction; and a restraining member that restricts the relative movement of the battery cells in the predetermined direction, The cooler has an internal space including a cooling channel through which a cooling fluid flows, and an outer wall that can be flexibly deformed in the predetermined direction. The aforementioned exterior wall is One of the battery cells has a first plate portion facing it in the predetermined direction, The other battery cell is opposed to the first plate portion in the predetermined direction, and the second plate portion is opposed to the first plate portion across the internal space in the predetermined direction, It has, The first plate portion is, A first contact portion that contacts the outer surface of one of the battery cells, A first non-contact portion is provided which is continuous with the first contact portion and forms a first gap between it and the one battery cell that allows for expansion and deformation of the one battery cell, and which is not in contact with the outer surface of the one battery cell. It has, The second plate portion is, The other second contact portion that contacts the outer surface of the battery cell, The second non-contact portion is continuous with the second contact portion and forms a second gap between it and the other battery cell that allows for expansion and deformation of the other battery cell, and is not in contact with the outer surface of the other battery cell and is not in contact with the inner surface of the first non-contact portion, A battery unit having the following features.

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