Battery pack

Abstract

The housing (200) includes a main body (210) having a bottom surface and a bottom surface cover (230) facing the bottom surface of the main body (210) from an outer side, the main body (210) includes a rib (215) rising from the bottom surface of the main body (210) toward an inner side and a recess facing the bottom surface cover (230), the rib (215) extends in a first direction between the first laminated body (11) and the second laminated body (12), and a refrigerant passage (210A) is formed between the recess of the main body (210) and the bottom surface cover (230). The main body (210) and the bottom cover (230) are fastened to each other at a fastening part (260), and at least a part of the fastening part (260) is located directly below the rib (215).

Description

Technical Field

[0001] The present technology relates to a battery pack. Background Art

[0002] A battery pack having a refrigerant passage formed in a pack case for cooling the battery cells is known in the art. Japanese Patent Application Publication Nos. 2020-35554, 2023-124435, and 2023-124436 are cited as examples of the prior art. Summary of the invention

[0003] From the viewpoint of improving the sealing performance of the refrigerant passage while suppressing structural complexity, conventional battery packs still have room for improvement.

[0004] An object of the present technology is to provide a battery pack capable of improving the sealing performance of a refrigerant passage with a simple structure.

[0005] This technology provides the following battery packs.

[0006] [1] A battery pack, wherein the battery pack comprises: a first stack and a second stack, the first stack and the second stack respectively comprising a plurality of battery cells arranged in a first direction and arranged in a second direction orthogonal to the first direction; and a shell, the shell accommodating the first stack and the second stack, the shell comprising a main body having a bottom surface and a bottom cover facing the bottom surface of the main body from the outside, the main body having a rib rising from the bottom surface of the main body toward the inside and a recess facing the bottom cover, the rib extending in the first direction between the first stack and the second stack, a refrigerant passage being formed between the recess of the main body and the bottom cover, the main body and the bottom cover being fastened to each other at a fastening portion, and at least a portion of the fastening portion being located directly below the rib.

[0007] [2] The battery pack according to [1], wherein the main body is formed of a cast component.

[0008] [3] The battery pack described in [1] or [2], wherein the bottom cover is formed of a plate-like member.

[0009] [4] The battery pack described in [1] or [2], wherein the bottom cover has another recessed portion facing the recessed portion of the body.

[0010] [5] The battery pack according to any one of [1] to [4], wherein the refrigerant passage extending in the first direction is provided on both sides of the fastening portion in the second direction.

[0011] [6] The battery pack according to any one of [1] to [5], wherein at least a portion of the refrigerant passage is located directly below the first stack and the second stack.

[0012] [7] A battery pack as described in any one of [1] to [5], wherein an exhaust passage communicating with an internal space of the main body is formed between the bottom surface of the main body and the bottom surface cover.

[0013] The foregoing and other objects, features, configurations and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a three-dimensional diagram of the battery pack.

[0015] Figure 2 It is a three-dimensional diagram of the battery pack contained in the battery pack.

[0016] Figure 3 This is a perspective view of a battery cell included in a battery pack.

[0017] Figure 4 It is a bottom view of the shell body of the battery pack.

[0018] Figure 5 yes Figure 4 V-V section view in.

[0019] Figure 6 yes Figure 4 VI-VI section view in.

[0020] Figure 7 1 is a schematic diagram showing an example of arrangement of refrigerant passages.

[0021] Figure 8 This is a schematic diagram showing an example of arrangement of refrigerant passages (part 2).

[0022] Fig. 9 3 is a schematic diagram showing an example of arrangement of refrigerant passages. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the present technology will be described. In addition, the same reference numerals are given to the same or corresponding parts, and their description may not be repeated.

[0024] In addition, in the embodiments described below, when the number, amount, etc. are mentioned, unless otherwise specified, the scope of the present technology is not necessarily limited to the number, amount, etc. In addition, in the following embodiments, each component is not an essential component for the present technology unless otherwise specified. In addition, the present technology is not limited to a configuration that necessarily exerts all the effects mentioned in the embodiments.

[0025] In addition, in this specification, the descriptions such as “comprise”, “include”, and “have” are not limiting. That is, when a certain structure is included, other structures other than the structure may be included or not.

[0026] In addition, in this specification, when geometrical terms and terms indicating position and direction relationships such as "parallel", "orthogonal", "oblique 45°", "coaxial", "along" and the like are used, these terms allow for manufacturing errors or slight variations. In this specification, when terms such as "upper side" and "lower side" are used to indicate relative positional relationships, these terms are used as terms indicating relative positional relationships in one state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, turning the entire mechanism upside down, etc.).

[0027] In this specification, the term "battery" is not limited to lithium-ion batteries, but may also include other batteries such as nickel-hydrogen batteries and sodium-ion batteries. In this specification, the positive electrode and the negative electrode are collectively referred to as "electrodes".

[0028] In this specification, "battery unit" is not limited to square structure, and may also include cylindrical, soft-pack, blade-shaped and other shaped units. "Battery unit" can be installed in hybrid electric vehicles (HEV: Hybrid Electric Vehicle), plug-in hybrid electric vehicles (PHEV: Plug-in Hybrid Electric Vehicle) and pure electric vehicles (BEV: Battery Electric Vehicle). However, the use of "battery unit" is not limited to vehicle use.

[0029] Figure 1 FIG. 1 is a perspective view of a battery pack according to the present embodiment. Figure 1 As shown, the battery pack 1 includes a case 200 . The battery pack 10 is accommodated in an internal space 200A (first space) of the case 200 .

[0030] exist Figure 1In the example, the battery pack 10 includes three battery packs 11, 12, and 13. The battery pack 11 (first stack), the battery pack 12 (second stack), and the battery pack 13 (third stack) include a plurality of battery cells arranged in the Y-axis direction (first direction), and are arranged in parallel with each other in the X-axis direction (second direction).

[0031] The housing 200 includes a main body 210, an upper cover 220, and a bottom cover 230. The main body 210, the upper cover 220, and the bottom cover 230 are fastened to each other at a plurality of fastening portions 240 each consisting of bolts or the like.

[0032] The internal space 200A of the housing 200 is formed by the main body 210 and the upper cover 220. A refrigerant passage 210A and an exhaust duct 210B (see FIG. 2 ) described below are formed between the bottom surface of the main body 210 and the bottom cover 230. Figure 4 , Figure 5 ).

[0033] like Figure 1 As shown, the housing 200 is provided with an opening 200B that allows the exhaust duct 210B to communicate with the outside of the housing 200, an inlet portion 200C through which the refrigerant enters the refrigerant passage 210A, and an outlet portion 200D through which the refrigerant exits the refrigerant passage 210A.

[0034] Figure 2 It is a perspective view of the battery pack 10 . Figure 2 The battery pack 10 shown includes battery cells 100 and insulating members 100A (cell spacers). The battery cells 100 and the insulating members 100A are alternately arranged along the Y-axis direction (first direction).

[0035] The battery cells 100 are rectangular battery cells, and a plurality of battery cells 100 are provided along the Y-axis direction. The plurality of battery cells 100 are electrically connected to each other via bus bars (not shown).

[0036] The insulating member 100A is provided between the plurality of battery cells 100. The insulating member 100A prevents unintended conduction of the adjacent battery cells 100. The insulating member 100A ensures electrical insulation of the adjacent battery cells 100.

[0037] By housing the battery pack 10 in the housing 20, a Figure 1 The battery pack 1 may be a structure in which the wall surface 22 of the housing 20 directly supports the stack of battery cells 100 and insulating members 100A (Cell-to-Pack structure, i.e., module-free structure), or a structure in which a battery module including a plurality of battery cells 100 and insulating members 100A is accommodated in the housing 20 (Cell-Module-Pack structure, i.e., conventional module structure).

[0038] Figure 3 is a perspective view showing the battery unit 100. Figure 3 As shown, the battery cell 100 has a square shape. The battery cell 100 has an electrode terminal 110 , a battery case 120 , and a gas discharge valve 130 .

[0039] The electrode terminal 110 is formed on the battery case 120. The electrode terminal 110 includes a positive terminal 111 and a negative terminal 112 arranged along the X-axis direction (second direction) orthogonal to the Y-axis direction (first direction). The positive terminal 111 and the negative terminal 112 are provided to be separated from each other in the X-axis direction.

[0040] The battery case 120 has a rectangular parallelepiped shape and forms the appearance of the battery cell 100. The battery case 120 includes a case body 120A that accommodates an electrode body and an electrolyte (not shown) and a sealing plate 120B that seals the opening of the case body 120A. The sealing plate 120B is joined to the case body 120A by welding.

[0041] The battery case 120 has an upper surface 121 , a lower surface 122 , a first side surface 123 , a second side surface 124 , and two third side surfaces 125 .

[0042] The upper surface 121 is a plane perpendicular to the Z-axis direction (third direction) (perpendicular to the Y-axis direction and the X-axis direction). The electrode terminal 110 is arranged on the upper surface 121. The lower surface 122 faces the upper surface 121 along the Z-axis direction.

[0043] Each of the first side surface 123 and the second side surface 124 is composed of a plane orthogonal to the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has the largest area among the multiple side surfaces of the battery case 120. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has a rectangular shape with the X-axis direction as the long side direction and the Z-axis direction as the short side direction when viewed in the Y-axis direction.

[0044] The plurality of battery cells 100 are stacked such that the first side surfaces 123 and the second side surfaces 124 face each other between the battery cells 100 and 100 adjacent to each other in the Y-axis direction. Thus, the positive terminals 111 and the negative terminals 112 are alternately arranged in the Y-axis direction of the stacked plurality of battery cells 100.

[0045] The gas discharge valve 130 is provided on the upper surface 121 . When the temperature of the battery cell 100 rises (thermal runaway) and the internal pressure of the battery case 120 becomes higher than a predetermined value due to the gas generated inside the battery case 120 , the gas discharge valve 130 discharges the gas to the outside of the battery case 120 .

[0046] Figure 4 is a bottom view of the main body 210 of the housing 200, Figure 5 yes Figure 4 V-V section view in.

[0047] like Figure 4 , Figure 5 As shown, a recessed portion facing the bottom cover 230 is formed in the main body 210 , and the recessed portion constitutes the refrigerant passage 210A and the exhaust duct 210B.

[0048] The main body 210 is a casting component made of a metal such as aluminum. The upper cover 220 and the bottom cover 230 are plate-shaped members made of a metal such as aluminum. However, the bottom cover 230 may be made of a casting component, and another concave portion facing the concave portion of the main body 210 may be provided, and the two concave portions facing each other may be combined to form the refrigerant passage 210A and the exhaust duct 210B.

[0049] The coolant passage 210A (third space) is formed between the bottom surface of the main body 210 and the bottom cover 230. The coolant passage 210A is formed to extend in the Y-axis direction directly below each of the battery packs 11, 12, and 13. Figure 4 In the example of FIG. 1 , the first portion 211A is formed directly below the battery pack 11, the second portion 212A is formed directly below the battery pack 12, and the third portion 213A is formed directly below the battery pack 13. The refrigerant flowing into the refrigerant passage 210A from the inlet portion 200C flows through the first portion 211A, then flows through the second portion 212A, and then flows through the third portion 213A, and then flows out from the outlet portion 200D to the outside of the housing 200. By making the refrigerant (e.g., water) flow directly below the battery packs 11, 12, and 13, the cooling of the battery unit 100 is promoted.

[0050] An exhaust duct 210B (second space) serving as an exhaust passage is formed between the bottom surface of the main body 210 and the bottom cover 230. The exhaust duct 210B is connected to the internal space 200A of the housing 200, and is also connected to the outside of the housing 200 through the opening 200B. A breathable breathing membrane 250 (membrane member) is provided in a manner that blocks the connecting portion between the internal space 200A of the housing 200 and the exhaust duct 210B. When the pressure of the internal space 200A does not exceed a predetermined pressure, the breathing membrane 250 allows air components to pass through while suppressing the intrusion of moisture into the internal space 200A. When the pressure of the internal space 200A exceeds a predetermined pressure (when the pressure rises abnormally), the breathing membrane 250 ruptures, and the connecting portion between the internal space 200A and the exhaust duct 210B is opened, thereby promoting the discharge of gas and the like from the internal space 200A.

[0051] The main body 210 and the bottom cover 230 are also fastened to each other at the fastening portion 260 provided between the first portion 211A and the second portion 212A and between the second portion 212A and the third portion 213A. In other words, the refrigerant passage 210A is provided on both sides of the fastening portion 260 in the X-axis direction so as to extend in the Y-axis direction.

[0052] Figure 6 yes Figure 4 The VI-VI section view in the figure. Figure 6 As shown, ribs 215 are provided that rise from the bottom surface of the body 210 toward the internal space 200A (inner side) of the case 200. The ribs 215 extend in the Y-axis direction (first direction) between the battery pack 11 (first stack) and the battery pack 12 (second stack).

[0053] exist Figure 6 The structure between the battery packs 11 and 12 is shown in FIG. 1 , and the same structure can be applied to the battery packs 12 and 13. In addition, the entirety of the battery packs 11, 12, and 13 in the Y-axis direction can be adopted. Figure 6 The structure of the rib 215 shown in the figure may also be adopted in a part of the Y-axis direction of the battery packs 11, 12, 13. Figure 6 The structure of the rib 215 is shown.

[0054] like Figure 6 As shown, the fastening portion 260 between the main body 210 of the housing 200 and the bottom cover 230 is located directly below the rib 215. The rib 215 functions as a partition between the battery packs 11 and 12 and as a part of the fastening portion 260. The base portion (near the bottom surface of the main body 210) of the rib 215 is widened to be wider than the tip portion in order to provide the fastening portion 260.

[0055] A refrigerant passage 210A is formed between the bottom surface of the main body 210 and the bottom cover 230. Since liquid passes through the refrigerant passage 210A, it is necessary to ensure water tightness (sealing) of the refrigerant passage 210A. On the other hand, it is also necessary to suppress the complexity of the structure of the housing 200 from the perspectives of reducing manufacturing costs and saving space when mounted on a vehicle.

[0056] In the battery pack 1 according to the present embodiment, as described above, as a fastening structure between the main body 210 of the housing 200 and the bottom cover 230, a fastening portion 260 is provided just below the rib 215 between the battery packs 11, 12, and 13 in addition to the fastening portion 240 provided along the outer circumference of the housing 200, thereby strengthening the fastening force between the two battery packs. As a result, the increase in the number of components can be suppressed, and the watertightness (sealing property) of the refrigerant passage 210A can be ensured.

[0057] Figures 7 to 9 It is a schematic diagram showing an example of arrangement of the refrigerant passage 210A. Figure 7 The configuration shown is similar to the above Figure 4 The example is equivalent to . Instead, Figure 8 As shown in FIG. 1 , the refrigerant passage 210A is set to face only one side of the Y-axis direction (such as Figure 7 The structure can also be as follows Fig. 9 As shown, the refrigerant passages 210A that reach directly below the battery packs 11, 12, and 13 are connected in parallel. Figures 7 to 9 The structure shown.

[0058] The embodiments of the present invention have been described above, but the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A battery pack, wherein: The battery pack has: a first laminate and a second laminate, each of which includes a plurality of battery cells arranged in a first direction and arranged in a second direction orthogonal to the first direction; and a housing that accommodates the first stack and the second stack, The housing includes a main body having a bottom surface and a bottom surface cover facing the bottom surface of the main body from the outside. The main body has a rib rising from the bottom surface of the main body toward the inner side and a recessed portion facing the bottom cover. The rib extends in the first direction between the first stack and the second stack. A refrigerant passage is formed between the recessed portion of the main body and the bottom cover. The main body and the bottom cover are fastened to each other at a fastening portion, and at least a portion of the fastening portion is located directly below the rib.

2. The battery pack according to claim 1, wherein: The main body is composed of a cast component.

3. The battery pack according to claim 1 or 2, wherein: The bottom cover is composed of a plate-shaped member.

4. The battery pack according to claim 1 or 2, wherein: The bottom cover has another recessed portion facing the recessed portion of the main body.

5. The battery pack according to claim 1 or 2, wherein: The refrigerant passage extending in the first direction is provided on both sides of the fastening portion in the second direction.

6. The battery pack according to claim 1 or 2, wherein: At least a portion of the refrigerant passage is located directly below the first stack and the second stack.

7. The battery pack according to claim 1 or 2, wherein: An exhaust passage communicating with an internal space of the main body is formed between the bottom surface of the main body and the bottom surface cover.

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