Battery case and method of manufacturing the battery case

Abstract

The present invention provides a battery case and a method for manufacturing the battery case. [Solution] The battery case includes at least two welded bottom plates, each of which has a fourth cavity for allowing a coolant to flow through. Each bottom plate includes a first side wall welded to an adjacent bottom plate, the first side wall having a predetermined width W2. The outermost bottom plate includes a second side wall spaced apart from the first side wall, the second side wall having a predetermined width W3, where 2W2 ≥ W3. The battery case of the present invention solves the problem of battery cases in the prior art, which are difficult to manufacture due to their complex structure.

Description

[Technical Field]

[0001] The present invention relates to the field of energy storage technology, and more particularly to a battery case and a method for manufacturing the battery case. [Background technology]

[0002] (Related Applications) This application claims priority to patent application serial number 202311395032.1, filed October 25, 2023, and patent application serial number 202322873372.2, filed October 25, 2023, the entire contents of which are incorporated herein by cross-reference.

[0003] Energy storage batteries are power storage components necessary for solar power generation systems, and their main function is to store power from the solar power generation system and supply power to loads when sunlight is insufficient, at night, or in an emergency. Energy storage batteries are usually installed inside a battery case, but battery cases in the prior art have a problem in that they are difficult to manufacture due to their complex structure. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of this, the present invention provides a battery case and a method for manufacturing the battery case, which are advantageous in solving the problem existing in battery cases in the prior art, that is, the high difficulty in manufacturing due to the high complexity of the structure of the battery case. [Means for solving the problem]

[0005] In a first aspect, the present invention provides a battery case comprising at least two welded bottom plates, each of which has a fourth cavity for a coolant to flow through, each of which includes a first side wall welded to an adjacent bottom plate, the first side wall having a predetermined width W2, and the outermost bottom plate including a second side wall spaced apart from the first side wall, the second side wall having a predetermined width W3, where 2W2≧W3.

[0006] The structural plate located at the bottom of the battery case is used to secure and support the batteries located inside the battery case, and this large-area structural plate is composed of at least two smaller bottom plates. Each bottom plate has a fourth cavity through which a coolant can flow. Specifically, the coolant located outside the battery case flows into the fourth cavity. Through thermal conduction, the coolant can absorb heat generated during operation of the batteries located in the bottom plate. The heat-absorbing coolant can then reflow outside the bottom plate. Circulating the coolant within the fourth cavity allows the batteries to operate within a normal temperature range and improves the battery's service life. As can be seen from the above, the bottom plate is not only used as part of the structural plate of the battery case to secure and support the batteries, but the fourth cavity located within the bottom plate may also be used to circulate the coolant to achieve heat dissipation. Compared to a case where a structural plate for fixing and supporting a battery is installed separately and a heat dissipation plate for heat dissipation is installed separately, the structure of the bottom plate and battery case of the present invention is less complex and the manufacturing difficulty of the bottom plate and battery case is also lower. Second, the bottom plate that comes into contact with the battery has an integrated heat dissipation function, forming a short heat conduction path, allowing battery heat to be quickly conducted to the coolant in the bottom plate, resulting in high heat dissipation efficiency. Because the bottom structural plate of a battery case has a large area, if a large-area structural plate were manufactured directly at once using conventional manufacturing processes, the structural strength and dimensional accuracy of the resulting structural plate would be relatively poor. On the other hand, the bottom structural plate of the battery case of the present invention is formed by welding at least two bottom plates with relatively small areas. By this arrangement, at least two bottom plates with relatively small areas may be manufactured first during the production process. The structural strength and dimensional accuracy of each bottom plate manufactured using conventional manufacturing processes are relatively high. The formed bottom plates may then be welded to form the bottom structural plate required for the battery case. The structural strength and dimensional accuracy of the resulting structural plate are also relatively high. This can better meet the actual usage needs. Here, each bottom plate includes a first side wall, and the first side wall of each bottom plate is welded to the first side wall of the adjacent bottom plate, i.e., the two welded first side walls form a connection structure for the two bottom plates. The welding method has the advantages of high strength and high connection reliability of the connection structure.The outermost base plate further includes a second side wall, which is configured to satisfy the shape, size, or structural strength of the base plate itself and is not intended for welding to another base plate. The first side wall has a predetermined width W2, and the second side wall has a predetermined width W3, where 2W2≧W3. Because the sum of the widths W2 of two adjacent first side walls is large, the width of the fusible connection area between the two adjacent base plates is large during the welding process. The width of the welded structure formed between the two adjacent base plates after welding is also large. This increases the structural strength of the welded structure between the two adjacent base plates, reducing the likelihood of structural problems such as cracks, breaks, or warping in the welded structure between the two adjacent base plates. This increases the operational reliability of the structural plate formed by welding at least two base plates.

[0007] Preferably, the relationship 7 mm≦W2≦10 mm or 3 mm≦W3≦8 mm is satisfied.

[0008] Preferably, the bottom plate further includes a second top wall and a second bottom wall, the second top wall being connected to the second bottom wall via the first side wall and the second side wall, the second top wall, the first side wall and the second bottom wall being at least part of a structure for surrounding and forming a fourth cavity, and the connection point of any one of the first side walls, on a side facing away from the adjacent first side wall, to the corresponding second top wall, includes a first chamfered portion, and / or the connection point of any one of the first side walls, on a side facing away from the adjacent first side wall, to the corresponding second bottom wall, includes a second chamfered portion.

[0009] Preferably, the first chamfered portion has a rounded chamfered structure, the first chamfered portion has a predetermined radius R1, and satisfies 1 mm≦R1≦3 mm, and / or the second chamfered portion has a rounded chamfered structure, the second chamfered portion has a predetermined radius R2, and satisfies 1 mm≦R2≦3 mm.

[0010] Preferably, the second top wall has a predetermined height H2 relative to the second bottom wall, which satisfies 5 mm≦H2≦8 mm.

[0011] Preferably, the bottom plate further includes a support portion located within the fourth cavity, and the second bottom wall is connected to the second top wall via the support portion.

[0012] Preferably, the support portion has a predetermined height H3 that satisfies 5 mm≦H3≦8 mm, and / or the support portion has a predetermined width W4 that satisfies 3 mm≦W4≦5 mm.

[0013] Preferably, the connection point between the support portion and the second top wall includes a third chamfered portion, and / or the connection point between the support portion and the second bottom wall includes a fourth chamfered portion.

[0014] Preferably, the third chamfered portion has a rounded chamfered structure, the third chamfered portion has a predetermined radius R3 and satisfies 1 mm≦R3≦3 mm, and / or the fourth chamfered portion has a rounded chamfered structure, the fourth chamfered portion has a predetermined radius R4 and satisfies 1 mm≦R4≦3 mm.

[0015] Preferably, the support portion has a plate-like structure, and the fourth cavity is partitioned by the support portion, thereby forming at least two parallel and communicating flow paths.

[0016] Preferably, the cross-sectional shape of the flow channel is rectangular, circular, semicircular, elliptical or hexagonal.

[0017] Preferably, the bottom plate further includes at least two separators positioned within the same flow path, the separators being parallel to the plate-shaped support, and each separator positioned within the same flow path being spaced apart along the flow direction of the flow path.

[0018] Preferably, the bottom plates are arranged so as to be distributed along the width or length direction of the battery case, the fourth cavities of the bottom plates are connected to each other, and one outermost bottom plate is provided with a liquid inlet port, and the other outermost bottom plate is provided with a liquid outlet port.

[0019] Preferably, the battery case further comprises a liquid inlet connecting pipe and a liquid outlet connecting pipe, the interior of the liquid inlet connecting pipe communicating with the liquid inlet port and the liquid inlet connecting pipe being hermetically connected to the bottom plate provided with the liquid inlet port, the interior of the liquid outlet connecting pipe communicating with the liquid outlet port and the liquid outlet connecting pipe being hermetically connected to the bottom plate provided with the liquid outlet port, and the liquid inlet connecting pipe and the liquid outlet connecting pipe being used to communicate with corresponding external flow ducts.

[0020] Preferably, the bottom plate is provided with a fifth opening communicating with the fourth cavity, and the battery case further includes a first closing member closing the fifth opening.

[0021] Preferably, the battery case further includes side plates, each bottom plate being distributed along the width direction or length direction of the battery case, the outermost bottom plate being integrally formed with or welded to the side plates, the side plates being provided with inwardly recessed slide grooves which are used for sliding engagement with the slide rails, and the side walls of the side plates which surround and form the slide grooves being provided with hanging holes which are drilled by hooks so that the side plates can be connected to the hooks.

[0022] The side plates of the battery case of the present invention may be provided with inwardly recessed slide grooves, and the fixing device for accommodating the battery case may include slide rails, with the slide grooves slidingly engaging with the slide rails. This assembly method facilitates quick, sliding attachment of the battery case to the fixing device, resulting in high assembly efficiency. Of course, this assembly method also facilitates quick, sliding detachment of the battery case from the fixing device, resulting in high removal efficiency. The side plates of the battery case may further be provided with lifting holes. The lifting holes are drilled by hooks of a lifting device (e.g., a crane, overhead travelling vehicle, crane, etc.) to connect the side plates to the hooks. This allows the hooks of the lifting device to quickly move the battery case. For example, the hooks may move the battery case to a position where the slide grooves and the slide rails are aligned to slide-engage the slide grooves with the slide rails. Alternatively, the hooks may move the battery case from the fixing device to another position. Because the hanging holes are provided on the side walls surrounding the sliding grooves in the side panels, this arrangement results in a highly compact structure between the sliding grooves and the hanging holes. The size of the structure for installing the sliding grooves and hanging holes in the side panels is small, and under the condition that the size in other directions is the same, the volume of the side panels is small, and the space occupied by the battery cases in the fixing device is small. This allows more battery cases to be accommodated in the space of the fixing device, resulting in a high loading rate. Correspondingly, the weight of the side panels is light, and the energy consumption for transporting the battery cases is low.

[0023] Preferably, a slide groove is provided on the outer wall of the side plate that is provided along the height direction of the battery case, and a hanging hole is provided on the top wall of the side plate that surrounds and forms the slide groove.

[0024] Preferably, a first cavity is further provided at the top of the side plate, the first cavity being connected to the slide groove through the hanging hole, and the first cavity being used to accommodate at least a part of the hook.

[0025] Preferably, a second cavity is further provided on the side of the side plate away from the slide groove, and a first opening is provided in the side plate, the first opening is connected to the hanging hole, the second cavity is connected to the slide groove via the first opening, and the second cavity is connected to the first cavity via the first opening.

[0026] Preferably, a third cavity is further provided at the bottom of the side plate, a second opening is provided in the side plate, the second opening is connected to the first opening, the second opening is also connected to the slide groove, the third cavity is connected to the second cavity via the second opening, and the third cavity is connected to the slide groove via the second opening.

[0027] Preferably, a third opening is provided on the outer wall of the side plate, the third opening communicates with the second opening, and the third opening is used to retract from the outer arc surface of the bent portion of the hook.

[0028] Preferably, the side plate includes a U-shaped rib portion, which is partitioned to form a first cavity, a second cavity, a third cavity, and a slide groove, and the hanging hole, the first opening, and the second opening are provided in the U-shaped rib portion.

[0029] Preferably, a fourth opening is provided on the outer wall of the side plate, the fourth opening communicates with the hanging hole, and the fourth opening is used to retract from the inner arc surface of the bent portion of the hook.

[0030] Preferably, the slide groove has a predetermined width W1 that satisfies 10 mm≦W1≦15 mm, and / or the slide groove has a predetermined depth H1 that satisfies 8 mm≦H1≦12 mm.

[0031] A second aspect of the present invention provides a method for manufacturing a battery case, the method comprising the steps of: Step S1: manufacturing a side plate and a bottom plate to be connected to each other by an integral molding process; and step S2 of welding the at least two bottom plates together by a friction welding process. [Effects of the Invention]

[0032] The interconnected outermost bottom and side plates are manufactured using a one-piece molding process, which has the advantages of reducing the number of molds required, increasing production efficiency, and improving the structural strength and dimensional accuracy between the outermost bottom and side plates. The one-piece molding process may be a casting process, an extrusion process, or an injection molding process. The first side walls of at least two bottom plates are welded using a friction welding process. Specifically, the temperature of the first side walls of the bottom plates is increased by high-speed friction until at least a portion of the first side walls melts, and then the molten portions of the first side walls of the two bottom plates are welded together. After the first side walls are cooled, a welded structure is formed between the first side walls of the two bottom plates. Because this welding process does not require auxiliary welding using other materials, the material of the welded structure between the first side walls of the two bottom plates is the same as the material of the bottom plates, i.e., the structural strength of the welded structure between the first side walls of the two bottom plates is the same as the structural strength of the bottom plates, and the resulting structural plate located at the bottom of the battery case has high operational reliability. Here, the first side walls of the two bottom plates can be rubbed against each other at high speed until at least a portion of the first side walls of the two bottom plates melts, or the curved side walls of the high-speed rotating cylinder can be used to rub the first side walls of the two bottom plates simultaneously, and then the melted portions of the first side walls of the two bottom plates can be welded.

[0033] In order to more clearly explain the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings referred to in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without exerting any effort equivalent to the inventive step. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a schematic diagram of the three-dimensional structure of a battery case according to one specific embodiment of the present invention. [Figure 2] FIG. 2 is a structural exploded schematic diagram of the battery case in FIG. [Figure 3] FIG. 3 is a locally enlarged schematic view of part A in FIG. 2. [Figure 4] FIG. 2 is a structural schematic diagram of the bottom plate and side plate. [Figure 5] FIG. 5 is a locally enlarged schematic view of part B in FIG. [Figure 6] FIG. 2 is a structural schematic diagram of a specific embodiment of a hook. [Figure 7] 3 is a cross-sectional view of the bottom plate and the side plate in FIG. 2 along the CC direction. [Figure 8] FIG. 8 is a locally enlarged schematic view of a portion D in FIG. 7. [Figure 9] FIG. 9 is a structural schematic diagram of the U-shaped rib portion in FIG. 8. [Figure 10] FIG. 8 is a structural schematic diagram of part E in FIG. 7. [Figure 11] 3 is a cross-sectional view of the bottom plate, the first closing member, and the second closing member in FIG. 2 taken along the line FF. [Figure 12] This is a schematic diagram of the structure of the two bottom plates. [Figure 13] This is a schematic diagram of the structure of the three bottom plates. [Figure 14] FIG. 13 is a locally enlarged schematic view of a portion G in FIG. [Figure 15] FIG. 2 is a structural schematic diagram of a first closing member according to one specific embodiment; [Figure 16] 10A and 10B are structural schematic diagrams of another specific embodiment of the first blocking member. [Figure 17] FIG. 13 is a locally enlarged schematic view of part H in FIG. 12. [Figure 18] FIG. 4 is a structural schematic diagram of a specific embodiment of a second blocking member. [Figure 19] 2 is a flowchart of a method for manufacturing a battery case according to a specific embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0035] In order to better understand the solution of the present invention, the following detailed description of an embodiment of the present invention will be given with reference to the drawings.

[0036] It is apparent that the described embodiments are only some of the embodiments of the present invention, and not all of the embodiments, and all other embodiments that a person skilled in the art can obtain based on the embodiments of the present invention without any inventive effort fall within the scope of protection of the present invention.

[0037] The terms used in the embodiments of the present invention are for the purpose of describing particular embodiments only and are not intended to limit the present invention. The singular forms "a kind," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise.

[0038] It should be understood that the term "and / or" used in this specification is only a relational relationship that describes related objects, and indicates that three types of relationships may exist. For example, A and / or B can indicate three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the symbol " / " in this specification generally indicates that the related objects before and after are in an "or" relationship.

[0039] As shown in FIG. 1 , a first embodiment of the present invention provides a battery case 10. The battery case accommodates a battery (not shown) inside, and the battery case protects the battery. In practical application, the battery case may be accommodated in a fixed device such as a holder, box, or cabinet. As shown in FIG. 2 , the battery case 10 includes a side panel 1, a bottom panel 2, a front panel 3, a rear panel 4, and a top cover 5. Two side panels 1 are connected to the bottom panel 2, and the two side panels 1 are arranged facing each other. The front panel 3 is connected to the bottom panel 2, and the rear panel 4 is connected to the bottom panel 2, and the front panel 3 and the rear panel 4 are arranged facing each other. At least two of the side panels 1, the front panel 3, and the rear panel 4 are connected to the top cover 5, and the side panels 1, the bottom panel 2, the front panel 3, the rear panel 4, and the top cover 5 enclose and form a space for accommodating a battery. The rest of this specification will first introduce the structure of the side panel 1, and then the structure of the bottom panel 2. The directions X, Y and Z described in this specification are perpendicular to each other, and the dashed lines in the drawings of this application are structural boundaries.

[0040] As shown in Fig. 3, the side plate 1 is provided with an inwardly recessed slide groove 11, which slides into a slide rail (not shown). As shown in Figs. 4 and 5, a hanging hole 12 is provided in the side wall of the side plate 1 that surrounds and forms the slide groove 11, and the hanging hole 12 is drilled by a hook 20 shown in Fig. 6, thereby connecting the side plate 1 to the hook 20.

[0041] As shown in FIG. 3 , the side plate 1 of the battery case 10 may be provided with an inwardly recessed slide groove 11. The fixing device (not shown) for accommodating the battery case 10 may include a slide rail, and the slide groove 11 may be slidably fitted into the slide rail. This assembly method facilitates quick, sliding attachment of the battery case 10 to the fixing device, resulting in high assembly efficiency. Of course, this assembly method also facilitates quick, sliding detachment of the battery case 10 from the fixing device, resulting in high removal efficiency. As shown in FIGS. 4 and 5 , the side plate 1 of the battery case 10 is further provided with a lifting hole 12. The lifting hole 12 is drilled by a hook 20 (shown in FIG. 6 ) of a lifting device (e.g., a crane, overhead travelling vehicle, crane, etc.) to connect the side plate 1 to the hook 20. This allows the hook 20 of the lifting device to quickly move the battery case 10. For example, the hook 20 may move the battery case 10 to a position where the slide groove 11 and the slide rail are aligned so that the slide groove 11 and the slide rail slide into engagement with each other. Alternatively, the hook 20 may move the battery case 10 from the fixing device to another position. Because the hanging holes 12 are provided on the side walls of the side panel 1 to surround and form the slide groove 11, this arrangement results in a high degree of structural compactness between the slide groove 11 and the hanging holes 12. When the size (e.g., size along the X direction) of the structure for installing the slide groove 11 and the hanging holes 12 on the side panel 1 is small and the size along other directions (e.g., direction Z and direction Y) is the same, the volume of the side panel 1 is small, and the space occupied by the battery case 10 in the fixing device is small. Therefore, many battery cases 10 can be accommodated within the space of the fixing device, resulting in a high loading rate. Accordingly, the weight of the side panel 1 is light, and the energy consumption for transporting the battery case 10 is low.

[0042] Here, as shown in FIG. 4, the slide groove 11 may be provided along the length direction of the side plate 1 (direction parallel to the direction Y).

[0043] As shown in FIGS. 7 and 8, the cross section of the slide groove 11 perpendicular to the direction Y may have a rectangular or polygonal shape such as an isosceles trapezoid.

[0044] Furthermore, in the embodiment of the present invention, the shape and number of the hanging holes 12 are not limited.

[0045] Optionally, as shown in FIG. 8 , the slide groove 11 is provided on the outer wall 1a of the side panel 1, which is arranged along the height direction of the battery case 10 (parallel to the X direction). Correspondingly, the slide rail of the fixing device (not shown) is also provided on the side wall structure of the fixing device, which is arranged along the height direction of the fixing device (parallel to the X direction). This arrangement simplifies the structure for sliding the fixing device and the battery case 10. Because the outer wall 1a is part of the structure of the battery case 10 at a general viewing angle, the slide groove 11 is easily visible to the user, which makes it easy for the user to quickly and accurately slide the slide groove 11 into the slide rail. For the same reason, the hanging hole 12 is also easily visible to the user, which makes it easy for the user to quickly and accurately drill the hanging hole 12 with the hook 20. Therefore, the above structural arrangement can improve the assembly efficiency and accuracy of the battery case 10. The hanging hole 12 is provided in the top wall 111 of the side plate 1 to surround and form the slide groove 11, and the gravity of the battery case 10 makes it difficult for the hook 20 to come off the hanging hole 12, so the connection reliability between the battery case 10 and the hook 20 is high.

[0046] In another embodiment (not shown), the bottom wall of the side panel 1 may be provided with the slide groove 11 and the hanging hole 12. The contents described hereinafter in this specification will mainly be described taking as an example the slide groove 11 and the hanging hole 12 provided on the outer wall 1a of the side panel 1.

[0047] Optionally, as shown in FIG. 8, a first cavity 13 is further provided on the top 1b of the side panel 1, and the first cavity 13 communicates with the slide groove 11 via the hanging hole 12, and the first cavity 13 accommodates at least a portion of the hook 20.

[0048] A portion of the structure of the hook 20 shown in FIG. 6 may be moved into the first cavity 13 via the slide groove 11 and hanging hole 12 shown in FIG. 8 to connect the hook 20 to the side panel 1. This arrangement provides a large space for the structure accommodating the hook 20 within the side panel 1, multiple connection points for the hook 20 within the internal structure of the side panel 1, a large connection area for the hook 20 within the internal structure of the side panel 1, and the connection points for the hook 20 within the internal structure of the side panel 1 are located close to the inside of the side panel 1. Accordingly, the length or volume of the structure of the hook 20 located within the side panel 1 may be increased, the structural strength of the hook 20 is increased, and the connection reliability between the side panel 1 and the hook 20 is high. The installation of the first cavity 13 reduces the weight of the battery case 10 and reduces the energy consumption of transporting the battery case 10.

[0049] As shown in FIG. 8, the first cavity 13 may be provided along the length direction of the side plate 1 (a direction parallel to the Y direction).

[0050] As shown in FIG. 8, the cross section of the first cavity 13 perpendicular to the direction Y may have a polygonal shape such as a rectangle.

[0051] Optionally, as shown in FIG. 8, a second cavity 15 is further provided on the side of the side plate 1 away from the slide groove 11, and a first opening 14 is provided in the side plate 1, the first opening 14 is connected to the hanging hole 12, the second cavity 15 is connected to the slide groove 11 via the first opening 14, and the second cavity 15 is connected to the first cavity 13 via the first opening 14.

[0052] 6 may be located within the first opening 14 and second cavity 15 shown in FIG. 8. This arrangement provides more space within the side panel 1 to accommodate the partial structure of the hook 20, more locations within the internal structure of the side panel 1 for connection with the hook 20, and a larger area within the internal structure of the side panel 1 for connection with the hook 20. Accordingly, the length or volume of the structure of the hook 20 located within the side panel 1 increases, the structural strength of the hook 20 increases, and the connection reliability between the side panel 1 and the hook 20 increases. The provision of the second cavity 15 reduces the weight 1 of the battery case 10, and reduces the energy consumption of transporting the battery case 10.

[0053] As shown in FIG. 8, the second cavity 15 may be provided along the length direction of the side plate 1 (a direction parallel to the Y direction).

[0054] As shown in FIG. 8, the cross section of the second cavity 15 perpendicular to the direction Y may have a polygonal shape such as a rectangle.

[0055] Optionally, as shown in FIG. 8, a third cavity 17 is further provided in the bottom 1c of the side plate 1, and a second opening 16 is provided in the side plate 1, the second opening 16 is connected to the first opening 14, the second opening 16 is connected to the slide groove 11, the third cavity 17 is connected to the second cavity 15 via the second opening 16, and the third cavity 17 is connected to the slide groove 11 via the second opening 16.

[0056] 6 may be located within the second opening 16 and the third cavity 17 shown in FIG. 8. This arrangement provides more space within the side panel 1 to accommodate the partial structure of the hook 20, more locations within the internal structure of the side panel 1 for connection with the hook 20, and a larger area within the internal structure of the side panel 1 for connection with the hook 20. Accordingly, the length or volume of the structure of the hook 20 located within the side panel 1 increases, the structural strength of the hook 20 increases, and the connection reliability between the side panel 1 and the hook 20 increases. The provision of the third cavity 17 reduces the weight 1 of the battery case 10, and reduces the energy consumption of transporting the battery case 10.

[0057] As shown in FIG. 8, the third cavity 17 may be provided along the length direction of the side plate 1 (a direction parallel to the Y direction).

[0058] As shown in FIG. 8, the cross section of the third cavity 17 perpendicular to the direction Y may have a polygonal shape such as a rectangle.

[0059] Optionally, as shown in FIG. 8, a third opening 18 is provided in the outer wall 1a of the side panel 1, and the third opening 18 is connected to the second opening 16, and the third opening 18 is used to retreat from the outer arc surface 201 of the bent portion of the hook 20 shown in FIG. 6.

[0060] At least a portion of the outer curved surface 201 of the bent portion of the hook 20 shown in Fig. 6 can be moved into the slide groove 11 or other internal space of the side panel 1 via the third opening 18 shown in Fig. 8, thereby facilitating connection of a portion of the structure of the hook 20 to the internal structure of the side panel 1. The provision of the third opening 18 reduces the possibility of problems occurring when the hook 20 and the structure of the side panel 1 become stuck during connection, making it easier for users to quickly connect the hook 20 to the side panel 1.

[0061] 5, the surface of the outer wall 1a of the side panel 1 that surrounds and forms the third opening 18 includes a first rounded chamfered structure 181, and the provision of the first rounded chamfered structure 181 can reduce the stress concentration in the structure that forms the third opening 18 in the side wall 1. Therefore, the possibility of cracking occurring in the structure that forms the third opening 18 in the side panel 1 is low.

[0062] Furthermore, in the embodiment of the present invention, the shape and area of ​​the third opening 18 are not limited.

[0063] Optionally, as shown in Fig. 8, the side panel 1 includes a U-shaped rib portion 1d, which divides the side panel 1 into a first cavity 13, a second cavity 15, a third cavity 17, and a slide groove 11. This arrangement reduces the weight of the side panel 1 and increases the structural strength of the side panel 1, reducing the possibility of structural problems such as bending deformation of the side panel 1. The hanging hole 12, the first opening 14, and the second opening 16 are provided in the U-shaped rib portion 1d, thereby forming an arrangement in which the slide groove 11, the hanging hole 12, the first cavity 13, the first opening 14, the second cavity 15, the second opening 16, and the third cavity 17 are connected to one another. In this way, some structures of the hook 20 can be positioned in the slide groove 11, the hanging hole 12, the first cavity 13, the first opening 14, the second cavity 15, the second opening 16, and the third cavity 17, respectively, thereby achieving the technical effect of improving the connection reliability between the side panel 1 and the hook 20 in the above content. This will not be described again here.

[0064] As shown in Figure 8, a portion of the first opening 14 is provided in a structure in the side panel 1 that is located between the first cavity 13 and the second cavity 15, and another portion of the first opening 14 is provided in a structure in the side panel 1 that is located between the second cavity 15 and the slide groove 11.

[0065] 9, the U-shaped rib portion 1d includes a first top wall 111, an inner wall 112, and a first bottom wall 113 for surrounding and forming the slide groove 11. The first top wall 111 separates the slide groove 11 from the first cavity 13, the inner wall 112 separates the slide groove 11 from the second cavity 15, and the first bottom wall 113 separates the slide groove 11 from the third cavity 17.

[0066] Optionally, as shown in FIG. 8, a fourth opening 19 is provided in the outer wall 1a of the side panel 1, and the fourth opening 19 is connected to the hanging hole 12, and the fourth opening 19 is used to retreat from the inner arc surface 202 of the bent portion of the hook 20 shown in FIG.

[0067] At least a portion of the inner curved surface 202 of the bent portion of the hook 20 shown in Fig. 6 can be moved into the slide groove 11 or other internal space of the side panel 1 via the fourth opening 19 shown in Fig. 8, thereby facilitating connection of a portion of the structure of the hook 20 to the internal structure of the side panel 1. The provision of the fourth opening 19 reduces the possibility of problems occurring when the hook 20 and the structure of the side panel 1 become stuck during connection, making it easier for users to quickly connect the hook 20 to the side panel 1.

[0068] 5, the surface of the outer wall 1a of the side panel 1 that surrounds and forms the fourth opening 19 includes a second rounded chamfered structure 191, and the provision of the second rounded chamfered structure 191 can reduce the stress concentration in the structure that forms the fourth opening 19 in the side wall 1. Therefore, the possibility of cracking occurring in the structure that forms the fourth opening 19 in the side panel 1 is low.

[0069] The number of the first openings 14, second openings 16, third openings 18, and fourth openings 19 is the same as the number of the hanging holes 12. That is, the first openings 14, second openings 16, third openings 18, and fourth openings 19 exist in correspondence with each hanging hole 12.

[0070] Optionally, as shown in Figure 8, the slide groove 11 has a predetermined width W1 (size along the direction X) that satisfies 10mm≦W1≦15mm, where W1 may be specifically 10mm, 11mm, 12mm, 13mm, 14mm, or 15mm.

[0071] As shown in Figure 8, when W1 is less than 10 mm, the width W1 of the slide groove 11 is small, and the width of the slide rail of the fixing device (not shown) is accordingly small, reducing the structural strength of the slide rail and resulting in low connection reliability between the battery case 10 and the fixing device. When the width W1 of the slide groove 11 is greater than 15 mm, the width W1 of the slide groove 11 is large, the height (size along direction X) of the side panel 1 is large, and the volume of the side panel 1 is large. As a result, a large amount of space in the fixing device is occupied by a single battery case 10, and the number of battery cases 10 that can be accommodated in the fixing device is reduced. In other words, the loading rate is low, the weight of the side panel 1 is heavy, and the energy consumption for transporting the battery cases 10 is high. Therefore, it is desirable that the width W1 of the slide groove 11 be 10 mm to 15 mm.

[0072] Optionally, as shown in FIG. 8, the slide groove 11 has a predetermined depth H1 (size along the direction Z), satisfying 8 mm≦H1≦12 mm, where H1 may be specifically 8 mm, 9 mm, 10 mm, 11 mm, or 12 mm.

[0073] As shown in Figure 8, when H1 is smaller than 8 mm, the depth H1 of the slide groove 11 is small, and there is little space in the slide groove 11 to accommodate the slide rail of the fixing device (not shown), making it easy for the slide rail to come out of the slide groove 11 and the sliding engagement between the slide groove 11 and the slide rail to become ineffective, i.e., the connection between the battery case 10 and the fixing device to become ineffective. When H2 is larger than 12 mm, the depth H1 of the slide groove 11 is large, reducing the structural strength of the side plate 1 and making it easy for structural problems such as deformation of the side plate 1 to occur. Therefore, it is desirable that the depth H1 of the slide groove 11 be 8 mm to 12 mm.

[0074] The following content of this specification will introduce the structure of the bottom plate 2.

[0075] As shown in FIG. 2 , a structural plate located at the bottom of the battery case 10 is used to secure and support a battery (not shown) located inside the battery case 10. This large-area structural plate is composed of at least two bottom plates 2 with smaller areas. As shown in FIGS. 10 and 11 , each bottom plate 2 has a fourth cavity 21a, which is used for circulating a coolant (not shown). Specifically, the coolant located outside the battery case 10 flows into the fourth cavity 21a. Through thermal conduction, the coolant can absorb heat generated during operation of a battery (not shown) located on the bottom plate 2. The coolant that has absorbed the heat can then reflow outside the bottom plate 2. Circulating the coolant back and forth within the fourth cavity 21a allows the battery to operate within a normal temperature range, improving the battery's service life. As can be seen from the above, the bottom plate 2 is used as part of the structural plate of the battery case 10 to secure and support the battery. The fourth cavity 21a formed within the bottom plate 2 can also be used to circulate coolant, thereby enabling the bottom plate 2 to achieve heat dissipation. The structure of the bottom plate 2 and battery case 10 according to the present invention is less complex and less difficult to manufacture than a separate structural plate for securing and supporting the battery and a separate heat dissipation plate for heat dissipation. Second, the bottom plate 2, which comes into contact with the battery, has an integrated heat dissipation function, forming a short heat conduction path. This allows battery heat to be quickly conducted to the coolant in the bottom plate 2, resulting in high heat dissipation efficiency. Because the bottom structural plate of the battery case 10 has a large area, if a large-area structural plate were manufactured directly at one time using conventional manufacturing processes, the structural strength and dimensional accuracy of the resulting structural plate would be relatively poor. On the other hand, the bottom structural plate of the battery case 10 according to the present invention is formed by welding at least two bottom plates 2 each having a relatively small area. Due to this arrangement, at least two bottom plates 2 with relatively small areas may be fabricated first during the production process. The structural strength and dimensional accuracy of each bottom plate 2 fabricated using the existing manufacturing process are relatively high. The fabricated bottom plates 2 may then be welded together to form the bottom plate structural plate required for the battery case 10. The structural strength and dimensional accuracy of the resulting structural plate are also relatively high.This can better meet actual usage needs. Each base plate 2 includes a first side wall 22a, and the first side wall 22a of each base plate 2 is welded to the first side wall 22a of the adjacent base plate 2. That is, the two welded first side walls 22a form a connection structure for the two base plates 2. The welding method has the advantages of high strength and high connection reliability. As shown in FIG. 8 , the outermost base plate 2 further includes a second side wall 22b, which is designed to satisfy the shape, size, or structural strength of the base plate 2 itself, and is not designed to be welded to another base plate 2. The first side wall 22a has a predetermined width W2 (size along the Z direction), and the second side wall 22b has a predetermined width W3 (size along the Z direction), where 2W2≧W3. With this setting, the sum of the widths W2 of the two adjacent first side walls 22a is large, so that during the welding process, the width of the meltable connection area between the two adjacent bottom plates 2 is large, the width of the welded structure formed between the two adjacent bottom plates 2 after welding is large, the structural strength of the welded structure between the two adjacent bottom plates 2 is high, and the welded structure between the two adjacent bottom plates 2 is unlikely to have structural problems such as cracks, breaks or bending, so that the operational reliability of the structural plate formed by welding at least two bottom plates 2 is high.

[0076] 12, when the structural plate of the bottom of the battery case 10 is composed of two bottom plates 2, each bottom plate 2 includes a first side wall 22a and a second side wall 22b spaced apart, the two first side walls 22a are welded together, and the second side wall 22b is not used for welding, and the fourth cavity 21a is located between the first side wall 22a and the second side wall 22b. As shown in FIG. 13, when the structural plate of the bottom of the battery case 10 is composed of at least three bottom plates 2, the at least three bottom plates 2 are arranged so as to be distributed along the width direction of the battery case 10 (a direction parallel to direction Z). The outermost bottom plate 2 may include a first side wall 22a and a second side wall 22b spaced apart, with a corresponding fourth cavity 21a located between the first side wall 22a and the second side wall 22b, and the bottom plate 2 located intermediate the two bottom plates 2 includes two first side walls 22a spaced apart, with the corresponding fourth cavity 21a located between the two first side walls 22a. The two first side walls 22a between two adjacent bottom plates 2 are welded, and the second side walls 22b are not used for welding.

[0077] In another embodiment (not shown), at least three bottom plates 2 are provided distributed along the length of the battery case 10 (parallel to the direction Y).

[0078] Optionally, as shown in Figure 8, the width W3 satisfies 3mm < W3 < 8mm, and specifically may be 3mm, 4mm, 5mm, 6mm, 7mm, or 8mm.

[0079] 8, when the width W3 of the second side wall 22b is less than 3 mm, the width of the second side wall 22b is too small, resulting in low structural strength and prone to structural problems such as cracks, breakage, or warping. When the width W3 of the second side wall 22b is greater than 10 mm, the width of the second side wall 22b is too large. Under conditions where the size of a single bottom plate 2 along the direction Z and the distance between the second side wall 22b and the first side wall 22a are limited, the size of the fourth cavity 21a along the direction Z is small, the amount of coolant that can be accommodated in the fourth cavity 21a is small, and heat dissipation efficiency is poor. Therefore, it is desirable that the width W2 of the first side wall 22a be 3 mm to 8 mm.

[0080] Alternatively, the width W2 satisfies 7 mm≦W2≦10 mm as shown in Fig. 10. Specifically, the width W2 may be 7 mm, 8 mm, 9 mm, or 10 mm.

[0081] 10, when the width W2 of the first side wall 22a is less than 7 mm, the width of a portion of the welded structure used to form the bottom plate 2 is too small, resulting in a reduced structural strength of the welded structure and the likelihood of structural problems such as cracks, breakage, and warping. When the width W2 of the first side wall 22a is greater than 10 mm, the width of the first side wall 22a is too large. Given the limited size of the single bottom plate 2 along the Z direction, the size of the fourth cavity 21a along the Z direction is small, reducing the amount of coolant that can be accommodated in the fourth cavity 21a and resulting in poor heat dissipation efficiency. Therefore, it is desirable for the width W2 of the first side wall 22a to be between 7 mm and 10 mm.

[0082] Optionally, as shown in Figure 10, the base plate 2 further includes a second top wall 23a and a second bottom wall 23b, where the second top wall 23a is connected to the second bottom wall 23b via the first side wall 22a and the second side wall 22b, and the second top wall 23a, the first side wall 22a, and the second bottom wall 23b are at least part of a structure for surrounding and forming the fourth cavity 21a. This configuration makes the base plate 2 structure less complex and easier to manufacture.

[0083] The structural plate at the bottom of the battery case 10 is composed of two bottom plates 2, each of which further includes a first side wall 22a and a second side wall 22b spaced apart from each other, and the second top wall 23a is connected to the second bottom wall 23b via the second side wall 22b. The second top wall 23a, the first side wall 22a, the second bottom wall 23b, and the second side wall 22b are structured to surround and form the fourth cavity 21a.

[0084] When the structural plates of the bottom of the battery case 10 are composed of at least three bottom plates 2, the outermost bottom plate 2 further includes a first side wall 22a and a second side wall 22b spaced apart, the second top wall 23a is connected to the second bottom wall 23b via the second side wall 22b, and the second top wall 23a, the first side wall 22a, the second bottom wall 23b, and the second side wall 22b are structured to surround and form the corresponding fourth cavity 21a. The bottom plate 2 located intermediate the two bottom plates 2 includes two first side walls 22a spaced apart, the second top wall 23a is connected to the second bottom wall 23b via the two first side walls 22a spaced apart, and the first side wall 22a, the second bottom wall 23b, and the two second side walls 22b are structured to surround and form the corresponding fourth cavity 21a.

[0085] The second top wall 23a secures and supports a battery (not shown). The battery case 10 may further include a thermally conductive adhesive disposed between the second top wall 23a and the battery. The second top wall 23a is connected to the battery via the thermally conductive adhesive, which can quickly conduct heat from the battery to the second top wall 23a.

[0086] The second top wall 23a may also be made of metal, which can improve heat conduction efficiency and quickly transfer heat to the coolant in the fourth cavity 21a.

[0087] The battery case may further include a heat absorption layer (not shown) located on the side of the second top wall 23a away from the second bottom wall 23b. The heat absorption layer may be made of a carbon-nitrogen co-permeable layer, a nitrogen-oxygen co-permeable layer, a carbon-oxygen co-permeable layer, or a carbon-nitrogen-oxygen co-permeable layer. For any of the above materials, at least a portion of the heat absorption layer may be black or a dark color close to black. Compared with other colors (such as stainless steel or the silver-white color of aluminum), a heat absorption layer with a black or dark color close to black appearance has a higher absorption efficiency for thermal radiation electromagnetic waves and can absorb a wider frequency range of thermal radiation electromagnetic waves. Therefore, the heat absorption layer can quickly and massively absorb thermal radiation electromagnetic waves generated during battery operation. That is, the heat absorption layer quickly absorbs heat from the battery using the principle of thermal radiation, and the second top wall 23a in contact with the heat absorption layer conducts the heat absorbed by the heat absorption layer to the coolant located in the fourth cavity 21a.

[0088] Optionally, as shown in FIG. 10, the connection point of any one of the first side walls 22a, on the side facing away from the adjacent first side wall 22a, to the corresponding second top wall 23a, includes a first chamfered portion 221. The provision of the first chamfered portion 221 can reduce the stress concentration at the connection point between the first side wall 22a and the second top wall 23a, thereby reducing the possibility of structural problems such as cracks, breaks, or deformation occurring at the connection point between the first side wall 22a and the second top wall 23a.

[0089] Optionally, as shown in FIG. 10, the connection point between the side of any first side wall 22a that is away from the adjacent first side wall 22a and the corresponding second bottom wall 23b includes a second chamfered portion 222. The provision of the second chamfered portion 222 can reduce the stress concentration at the connection point between the first side wall 22a and the second bottom wall 23b, thereby reducing the possibility of structural problems such as cracks, breaks, or deformation occurring at the connection point between the first side wall 22a and the second bottom wall 23b.

[0090] Optionally, as shown in Fig. 10, the first chamfered portion 221 has a rounded chamfer structure and has a predetermined radius R1, which satisfies 1 mm ≤ R1 ≤ 3 mm, and the radius R1 may be specifically 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0091] As shown in FIG. 10 , when the radius R1 is less than 1 mm, the radius R1 of the first chamfered portion 221 is small. This results in high stress concentration at the connection between the first side wall 22a and the second top wall 23a, which can lead to structural problems such as cracks, breakage, or deformation at the connection between the first side wall 22a and the second top wall 23a. Furthermore, while ensuring dimensional accuracy, it is difficult to manufacture a first chamfered portion 221 with a small radius R1. When the radius R1 is greater than 3 mm, the radius R1 of the first chamfered portion 221 is large, which increases the volume of the connection between the first side wall 22a and the second top wall 23a. Therefore, even if the volume of a single bottom plate 2 is constant, the volume of the fourth cavity 21a is small, which reduces the amount of coolant that can be accommodated in the fourth cavity 21a, resulting in poor heat dissipation efficiency. Therefore, it is desirable for the radius R1 to be between 1 mm and 3 mm.

[0092] In another embodiment (not shown), the first chamfer 221 may be a corner chamfer structure.

[0093] Optionally, as shown in Fig. 10, the second chamfered portion 222 has a rounded chamfer structure and has a predetermined radius R2 that satisfies 1 mm ≤ R2 ≤ 3 mm, where the radius R2 may be 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0094] As shown in FIG. 10 , when the radius R2 is less than 1 mm, the radius R2 of the second chamfered portion 222 is small. This results in high stress concentration at the connection between the first side wall 22a and the second bottom wall 23b, making the connection prone to cracks, breaks, deformation, and other structural problems. Furthermore, while ensuring dimensional accuracy, it is difficult to manufacture the second chamfered portion 222 with a small radius R2. When the radius R2 is greater than 3 mm, the radius R2 of the second chamfered portion 222 is large, and the volume of the connection between the first side wall 22a and the second bottom wall 23b is large. Therefore, under the condition that the volume of a single bottom plate 2 is constant, the volume of the fourth cavity 21a is small, the amount of coolant that can be accommodated in the fourth cavity 21a is small, and heat dissipation efficiency is poor. Therefore, it is desirable for the radius R2 to be between 1 mm and 3 mm.

[0095] In another embodiment (not shown), the second chamfer 222 may be a corner chamfer structure.

[0096] Optionally, as shown in Figure 10, the second top wall 23a has a predetermined height H2 relative to the second bottom wall 23b, which satisfies 5mm≦H2≦8mm, and the height H2 may be specifically 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, or 8mm.

[0097] 10, when the height H2 is less than 5 mm, the height of the fourth cavity 21a located between the second top wall 23a and the second bottom wall 23b is small, the amount of coolant that can be accommodated in the fourth cavity 21a is small, and heat dissipation efficiency is poor. When the height H2 is greater than 8 mm, the thickness of the bottom plate 2 is large, the weight of the battery case 10 is heavy, and the energy consumption for transporting the battery case 10 is large. Therefore, it is desirable that the height H2 be 5 mm to 8 mm.

[0098] Optionally, as shown in Fig. 10, the bottom plate 2 further includes a support 22c located within the fourth cavity 21a, and the second bottom wall 23b is connected to the second top wall 23a via the support 22c. This arrangement improves the structural strength of the bottom plate 2, reducing the likelihood of structural problems such as bending, cracking, or breakage occurring in the second top wall 23a and the second bottom wall 23b.

[0099] The support portion 22c may have a rod-like, column-like, plate-like, or disc-like shape. In the following description of this specification, the plate-like support portion 22c will be mainly described as an example. In the embodiments of the present invention, the number of the support portions 22c is not limited.

[0100] Optionally, as shown in Figure 10, the support portion 22c has a predetermined height H3 (size parallel to the direction X) that satisfies 5mm≦H3≦8mm, and the height H3 may be specifically 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, or 8mm.

[0101] 10, the height H2 of the second top wall 23a relative to the second bottom wall 23b is the same as the height H3 of the support portion 22c. The technical effects resulting from setting the numerical range of the height H3 include the technical effects resulting from setting the numerical range of the height H2 described above, and will not be described again here.

[0102] Optionally, as shown in Figure 10, the support portion 22c has a predetermined width W4 (size parallel to the direction Z) that satisfies 3 mm ≤ W4 ≤ 5 mm, and the width W4 may be specifically 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm.

[0103] 10, when the width W4 of the support portion 22c is smaller than 3 mm, the structural strength of the support portion 22c is low, the effect of the support portion 22c in improving the structural strength of the bottom plate 2 is weak, and structural problems such as bending, cracking, or breakage are likely to occur in the second top wall 23a and the second bottom wall 23b. When the width W4 of the support portion 22c is larger than 5 mm, the space occupied by the support portion 22c in the fourth cavity 21a is large, the amount of coolant that can be accommodated in the fourth cavity 21a is small, and heat dissipation efficiency is poor. Therefore, it is desirable that the width W4 of the support portion 22c be 3 mm to 5 mm.

[0104] Optionally, as shown in Fig. 10, the connection between support portion 22c and second top wall 23a includes a third chamfered portion 223. The provision of third chamfered portion 223 can reduce stress concentration at the connection between support portion 22c and second top wall 23a, thereby reducing the possibility of structural problems such as cracks, breaks, or deformation occurring at the connection between support portion 22c and second top wall 23a.

[0105] Optionally, as shown in Fig. 10, the connection portion between the support portion 22c and the second bottom wall 23b includes a fourth chamfered portion 224. The provision of the fourth chamfered portion 224 can reduce stress concentration at the connection portion between the support portion 22c and the second bottom wall 23b, thereby reducing the possibility of structural problems such as cracks, breaks, or deformation occurring at the connection portion between the support portion 22c and the second bottom wall 23b.

[0106] Optionally, as shown in Fig. 10, the third chamfered portion 223 has a rounded chamfer structure and has a predetermined radius R3 that satisfies 1 mm≦R3≦3 mm, where the radius R3 may be 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0107] As shown in Figure 10, when radius R3 is less than 1 mm, the radius R3 of the third chamfered portion 223 is small, resulting in high stress concentration at the connection between support portion 22c and second top wall 23a, and structural problems such as cracks, breakage, or deformation at the connection between support portion 22c and second top wall 23a. Furthermore, manufacturing a third chamfered portion 223 with a small radius R3 is difficult while ensuring dimensional accuracy. When radius R3 is greater than 3 mm, the radius R3 of the third chamfered portion 223 is large, resulting in a large volume at the connection between support portion 22c and second top wall 23a. Under the condition that the volume of a single bottom plate 2 is constant, the volume of fourth cavity 21a is small, the amount of coolant that can be accommodated in fourth cavity 21a is small, and heat dissipation efficiency is poor. Therefore, it is desirable for radius R3 to be between 1 mm and 3 mm.

[0108] In another embodiment (not shown), the third chamfer 223 is a corner chamfer structure.

[0109] Optionally, as shown in Fig. 10, the fourth chamfered portion 224 has a rounded chamfer structure and has a predetermined radius R4 that satisfies 1 mm ≤ R4 ≤ 3 mm, where the radius R4 may be 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0110] As shown in FIG. 10 , when radius R4 is less than 1 mm, the radius R4 of the fourth chamfered portion 224 is small, resulting in high stress concentration at the connection between support portion 22c and second bottom wall 23b, and structural problems such as cracks, breakage, or deformation at the connection between support portion 22c and second bottom wall 23b. Furthermore, manufacturing a fourth chamfered portion 224 with a small radius R4 is difficult while ensuring dimensional accuracy. When radius R4 is greater than 3 mm, the radius R4 of the fourth chamfered portion 224 is large, resulting in a large volume at the connection between support portion 22c and second bottom wall 23b. Therefore, under the condition that the volume of a single bottom plate 2 is constant, the volume of fourth cavity 21a is small, the amount of coolant that can be accommodated in fourth cavity 21a is small, and heat dissipation efficiency is poor. Therefore, it is desirable for radius R4 to be between 1 mm and 3 mm.

[0111] In another embodiment (not shown), the fourth chamfer 224 is a corner chamfer structure.

[0112] Optionally, as shown in FIG. 11, the support portion 22c has a plate-like structure, and the fourth cavity 21a is partitioned by the support portion 22c to form at least two parallel and communicating flow paths 211. This configuration allows the flow paths 211 to guide the coolant to flow regularly along the extension direction of the flow paths 211 (a direction parallel to the Y direction), improving the flow efficiency of the coolant. The flow paths 211 are then further used to divide the coolant into at least two flow paths, each of which absorbs heat from a corresponding portion of the bottom plate 2, and the difference in the efficiency of heat transfer between each portion of the bottom plate 2 to the coolant is small. Therefore, the configuration of the flow paths 211 allows for improved heat dissipation efficiency.

[0113] The greater the number of support portions 22c, the greater the number of flow channels 211 that are formed.

[0114] Optionally, the cross-sectional shape of the flow passage 211 is rectangular (as shown in FIG. 10), circular, semicircular, elliptical, or hexagonal, and any of the above cross-sectional shapes of the flow passage 211 can meet the demand for the flow of the coolant.

[0115] Optionally, as shown in FIG. 11, the bottom plate 2 further includes at least two separators 22d located within the same flow path 211, the separators 22d being parallel to the plate-shaped support portion 22c, and each separator 22d located within the same flow path 211 being spaced apart along the flow direction of the flow path 211 (a direction parallel to direction Y).

[0116] As shown in FIG. 11 , as the coolant flows through the flow path 211, multiple stacked flat flow layers are easily formed along the flow direction of the flow path 211. The flat flow layers in the coolant near the support 22c are likely to absorb heat from the support 22c, while the flat flow layers in the coolant near the second top wall 23a are likely to absorb heat from the second top wall 23a. However, the heat conduction efficiency between the flat flow layers is poor, making it difficult for heat to be transferred to the inner flat flow layers in the coolant, resulting in poor heat dissipation efficiency. However, by providing a gap between two adjacent separators 22d, the coolant is likely to form turbulence in the gap between the two adjacent separators 22d. The turbulence can break down the flat flow layers of the coolant and redistribute heat within the coolant. This means that heat from the outside of the coolant is more easily transferred to the inside of the coolant, thereby improving heat dissipation efficiency.

[0117] The height of the separator 22d may be smaller than the height H2 of the fourth cavity 21a or the height H3 of the support portion 22c. The separator 22d may be connected only to the second top wall 23a, or the separator 22d may be connected only to the second bottom wall 23b. The height of the separator 22d may be equal to the height H2 of the fourth cavity 21a or the height H3 of the support portion 22c. For example, the separator 22d is connected not only to the second top wall 23a but also to the second bottom wall 23b. The width of the separator 22d (size along the direction Z) is smaller than the width of the flow path 211 (size along the direction Z), and the ratio of the width of the separator 22d to the width of the flow path 211 is in the range of 1:10 to 2:10. The length of separator 22d (size along direction Y) is smaller than the length of support portion 22c (size along direction Y), and the ratio of the length of separator 22d to the length of support portion 22c is in the range of 1:20 to 2:20.

[0118] Furthermore, the position of separator 22d in flow path 211 along direction Z and along direction Y is not limited.

[0119] Optionally, as shown in FIG. 12 , the bottom plates 2 are arranged distributed along the width direction of the battery case 10 (a direction parallel to the Z direction). The fourth cavities 21a of the bottom plates 2 are connected to each other. One outermost bottom plate 2 is provided with a liquid inlet 24a, and the other outermost bottom plate 2 is provided with a liquid outlet 24b. With this arrangement, the coolant outside the bottom plates 2 can flow from the liquid inlet 24a of one outermost bottom plate 2 into the fourth cavity 21a of the corresponding bottom plate 2. The fourth cavities 21a of each bottom plate 2 are connected in sequence to form a single cooling path that guides the coolant to flow in one direction. The coolant may pass through each fourth cavities 21a in sequence, or the coolant may flow from the fourth cavity 21a of the other outermost bottom plate 2 to the outside of the bottom plate 2 via the corresponding liquid outlet 24b. With this arrangement, the coolant flows in one direction from the liquid inlet 24a to the liquid outlet 24b, making it easy to control the flow of the coolant.

[0120] 11 and 14, each bottom plate 2 is provided with a sixth opening 25b communicating with the fourth cavity 21a, and the sixth openings 25b of two adjacent welded bottom plates 2 communicate with each other. That is, the coolant located in the fourth cavity 21a of one bottom plate 2 can flow through the sixth opening 25b into the fourth cavity 21a of the other bottom plate 2. The second top wall 23a, the first side wall 22a, and the second bottom wall 23b surround and form the sixth opening 25b.

[0121] In another embodiment (not shown), the bottom plates 2 may be provided so as to be distributed along the length direction of the battery case 10 (the direction parallel to the direction Y).

[0122] Optionally, as shown in FIG. 2, the battery case 10 further includes an inlet connecting pipe 6, which communicates with the inlet port 24a shown in FIG. 12 and is used to communicate with a corresponding external flow guide pipe (not shown). With this arrangement, the coolant can flow from the external flow guide pipe through the inlet connecting pipe 6 and the inlet port 24a in this order into the fourth cavity 21a of the bottom plate 2. The inlet connecting pipe 6 is hermetically connected (for example, by welding or sealing with a sealant) to the bottom plate 2, which is provided with the inlet port 24a, thereby reducing the possibility of coolant leakage between the inlet connecting pipe 6 and the bottom plate 2.

[0123] Optionally, as shown in FIG. 2, the battery case 10 further includes an outlet connecting pipe 7, which communicates with the outlet port 24b shown in FIG. 12 and is used to communicate with a corresponding external guiding pipe (not shown). With this arrangement, the coolant can flow from the fourth cavity 21a of the bottom plate 2 into the corresponding external guiding pipe via the outlet port 24b and the outlet connecting pipe 7 in that order. The outlet connecting pipe 7 is hermetically connected (for example, by welding or sealing with a sealant) to the bottom plate 2, which is provided with the outlet port 24b, thereby reducing the possibility of coolant leakage between the outlet connecting pipe 7 and the bottom plate 2.

[0124] Optionally, as shown in Fig. 14, the bottom plate 2 may be provided with a fifth opening 25a communicating with the fourth cavity 21a. This arrangement facilitates the manufacturing of the bottom plate 2 having the fifth opening 25a and the fourth cavity 21a by an extrusion molding process. As shown in Figs. 15 and 16, the battery case 10 may further include a first closing member 8. The first closing member 8 is used to close the fifth opening 25a. The first closing member 8 has a blocking effect on the coolant located in the fourth cavity 21a, reducing the possibility of the coolant leaking out of the bottom plate 2 through the fifth opening 25a.

[0125] The first closing member 8 may be welded to the bottom plate 2 or may be adhered with a sealant.

[0126] Furthermore, a fifth opening 25a is provided on both ends of the bottom plate 2 along the direction X, and the battery case 10 includes two first closing members 8, each of which closes a corresponding fifth opening 25a.

[0127] 15 and 16, the first closing member 8 includes at least two protrusions 81 spaced apart along the direction Z, and the protrusions 81 perforate and close the fifth opening 25a. The height of the protrusions 81 along the direction X is the same as the height H2 of the fourth cavity 21a along the direction X.

[0128] As shown in Figures 15 and 16, a spacing space 82 is provided between every two protrusions 81. In the embodiment of the present invention, the number of protrusions 81 and spacing spaces 82 provided is not limited. Some spacing spaces 82 are fitted into the support portions 22c to connect some of the support portions 22c to some of the protrusions 81, and some spacing spaces 82 are fitted into the first side walls 22a to connect some of the first side walls 22a to some of the protrusions 81. This arrangement further improves the reliability of the connection between the first closing member 8 and the bottom plate 2. Furthermore, each first closing member 8 is connected to at least two bottom plates 2, further improving the structural strength of the structural plate consisting of at least two bottom plates 2.

[0129] Among the fifth openings 25a, there are some that communicate with the sixth openings 25b, and there are corresponding protrusions 81 that open the sixth openings 25b, but the sixth openings 25b are not blocked by the protrusions 81.

[0130] Optionally, as shown in FIG. 8 , the outermost bottom plate 2 may further include a third side wall 22e spaced apart from the second side wall 22b. That is, the second side wall 22b is located between the first side wall 22a and the third side wall 22e, and the second top wall 23a is connected to the second bottom wall 23b via the third side wall 22e. The second top wall 23a, the third side wall 22e, the second bottom wall 23b, and the second side wall 22b surround and form a fifth cavity 21b within the outermost bottom plate 2. This configuration reduces the weight of the outermost bottom plate 2, which in turn reduces the weight of the battery case 10 and the energy consumption required to transport the battery case 10.

[0131] Here, as shown in FIG. 11, the fifth cavity 21b is provided along the Y direction.

[0132] Optionally, as shown in FIG. 17, the outermost bottom plate 2 further includes a seventh opening 25c communicating with the fifth cavity 21b. As shown in FIG. 18, the battery case 10 may further include a second closing member 9. The second closing member 9 closes the seventh opening 25c, and accordingly, at least a portion of the second closing member 9 is located within the fifth cavity 21b. The outermost bottom plate 2 further includes a first through-hole 26 penetrating the second top wall 23a and the second bottom wall 23b. When the second closing member 9 does not close the seventh opening 25c, the first through-hole 26 can communicate with the fifth cavity 21b. The second closing member 9 further includes a second through-hole 91. When the second blocking member 9 blocks the seventh opening 25c and at least a portion of the second blocking member 9 is positioned within the fifth cavity 21b, the second through hole 91 communicates with the first through hole 26, thereby forming a hole that can serve a positioning or connecting role, and when the second blocking member 9 is connected to the bottom plate 2, it can serve to improve the structural strength of the portion of the bottom plate 2 where the first through hole 26 is provided.

[0133] Optionally, as shown in FIG. 4, the outermost bottom plate 2 is integrally connected or welded to the side plate 1.

[0134] When the outermost bottom plate 2 and the side plate 1 are integrally molded (for example, integrally molded using a casting process, an extrusion molding process, or an injection molding process), there are advantages in reducing the number of molds to be manufactured, increasing production efficiency, and improving the structural strength and dimensional accuracy between the outermost bottom plate 2 and the side plate 1.

[0135] A second aspect of the present invention provides a method for manufacturing a battery case, as shown in Fig. 19. As shown in Fig. 2, the manufactured battery case 10 includes two side plates 1 and at least two bottom plates 2, each of which is distributed along the width direction of the battery case 10 (parallel to direction Z), and the outermost bottom plate 2 is connected to the corresponding side plate 1. The method for manufacturing a battery case according to the present invention includes steps S1 and S2. In step S1, the side plate 1 and the bottom plate 2 are manufactured by an integral molding process. In step S2, at least two bottom plates 2 are welded together by a friction welding process. The outermost bottom plate 2 and side plate 1 connected to each other as shown in Figure 4 are manufactured by an integral molding process, which has the advantages of reducing the number of molds to be manufactured, improving production efficiency, and improving the structural strength and dimensional accuracy between the outermost bottom plate 2 and side plate 1. The integral molding process may be a casting process, an extrusion molding process, or an injection molding process.

[0136] 10 shows that the first side walls 22a of at least two bottom plates 2 are welded by a friction welding process. Specifically, the temperature of the first side walls 22a of the bottom plates 2 is increased by high-speed friction until at least a portion of the first side walls 22a melts. The melted portions of the first side walls 22a of the two bottom plates 2 are then welded together. After the first side walls 22a are cooled, a welded structure is formed between the first side walls 22a of the two bottom plates 2. Because this welding process does not require auxiliary welding using other materials, the material of the welded structure between the first side walls 22a of the two bottom plates 2 is the same as the material of the bottom plates 2. This means that the structural strength of the welded structure between the first side walls 22a of the two bottom plates 2 is the same as that of the bottom plates 2. This results in high operational reliability for the resulting structural plate located at the bottom of the battery case 10.

[0137] Here, the first side walls 22a of the two bottom plates 2 can be rubbed against each other at high speed until at least a portion of the first side walls 22a of the two bottom plates 2 melts, or the curved side walls of a high-speed rotating cylinder can be used to rub the first side walls 22a of the two bottom plates 2 simultaneously, and the melted portions of the first side walls 22a of the two bottom plates 2 can be welded. [Explanation of symbols]

[0138] 10 Battery case 1 Side Panel 1a Outer wall 1b top 1c bottom 1d U-shaped rib 11 Slide groove 111 1st top wall 112 Inner wall 113 First Bottom Wall 12 Hanging hole 13 First cavity 14 First opening 15 Second cavity 16 Second opening 17 Third cavity 18 Third Opening 181 First rounded chamfer structure 19 4th Opening 191 Second rounded chamfer structure 2 Bottom plate 21a 4th cavity 211 Channel 21b 5th cavity 22a 1st side wall 221 First chamfer 222 Second chamfer 22b 2nd side wall 22c Support part 223 Third chamfer 224 4th chamfer 22d Separator 22e 3rd side wall 23a 2nd top wall 23b 2nd bottom wall 24a Liquid inlet 24b Liquid outlet 25a 5th opening 25b 6th opening 25c 7th opening 26 First through hole 3 Front panel 4 Rear plate 5 Top lid 6 Inlet connection pipe 7 Outlet connection pipe 8 First blocking member 81 Protrusion 82 Spacing 9 Second blocking member 91 Second through hole 20 Hook 201 Bend part outer arc surface 202 Inner arc surface of bending part

Claims

1. A battery case, The battery case (10) comprises at least two welded bottom plates (2), each of which has a fourth cavity (21a) for allowing a coolant to flow therethrough, each of which has a first side wall (22a) welded to an adjacent bottom plate (2), and the outermost bottom plate (2) comprises a second side wall (22b) spaced apart from the first side wall (22a); the battery case (10) further comprises side plates (1), each of which is arranged so as to be distributed along the width direction or length direction of the battery case (10), and the outermost bottom plate (2) and the side plate (1) are of an integral structure.

2. The battery case according to claim 1, characterized in that the side plate (1) is provided with an inwardly recessed slide groove (11), which is used for sliding engagement with a slide rail, and the side wall of the side plate (1) that surrounds and forms the slide groove (11) is provided with a hanging hole (12), which is drilled by the hook (20) so that the side plate (1) is connected to the hook (20).

3. The battery case according to claim 2, characterized in that the slide groove (11) is provided in an outer wall (1a) of the side plate (1) that is provided along the height direction of the battery case (10), and the hanging hole (12) is provided in a top wall (111) of the side plate (1) that surrounds and forms the slide groove (11).

4. The battery case according to claim 3, characterized in that a first cavity (13) is further provided on the top (1b) of the side plate (1), the first cavity (13) is connected to the slide groove (11) via the hanging hole (12), and the first cavity (13) is used to accommodate at least a portion of the hook (20).

5. The battery case of claim 4, characterized in that a second cavity (15) is further provided on the side of the side plate (1) away from the slide groove (11), a first opening (14) is provided in the side plate (1), the first opening (14) is connected to the hanging hole (12), the second cavity (15) is connected to the slide groove (11) via the first opening (14), and the second cavity (15) is connected to the first cavity (13) via the first opening (14).

6. The battery case of claim 5, further comprising: a third cavity (17) in the bottom (1c) of the side plate (1); a second opening (16) in the side plate (1); the second opening (16) communicating with the first opening (14); the second opening (16) also communicating with the slide groove (11); the third cavity (17) communicating with the second cavity (15) via the second opening (16); and the third cavity (17) communicating with the slide groove (11) via the second opening (16).

7. The battery case according to claim 6, characterized in that a third opening (18) is provided in the outer wall (1a) of the side plate (1), the third opening (18) is connected to the second opening (16), and the third opening (18) is used to escape from the outer arc surface (201) of the bent portion of the hook (20).

8. The battery case according to claim 6, characterized in that the side plate (1) includes a U-shaped rib portion (1d), which is partitioned to form the first cavity (13), the second cavity (15), the third cavity (17), and the slide groove (11), and the hanging hole (12), the first opening (14), and the second opening (16) are provided in the U-shaped rib portion (1d).

9. The battery case according to claim 3, characterized in that a fourth opening (19) is provided in the outer wall (1a) of the side plate (1), the fourth opening (19) is connected to the hanging hole (12), and the fourth opening (19) is used to retract from the inner arc surface (202) of the bent portion of the hook (20).

10. The battery case according to claim 2, characterized in that the slide groove (11) has a predetermined width W1 that satisfies 10 mm≦W1≦15 mm, and / or the slide groove (11) has a predetermined depth H1 that satisfies 8 mm≦H1≦12 mm.

11. The bottom plates (2) are provided so as to be distributed along the width direction or length direction of the battery case (10), the fourth cavities (21 a) of the bottom plates (2) are connected to each other, one of the outermost bottom plates (2) is provided with a liquid inlet (24 a), and the other outermost bottom plate (2) is provided with a liquid outlet (24 b), The battery case (10) further includes a liquid inlet connecting pipe (6) and a liquid outlet connecting pipe (7), the interior of the liquid inlet connecting pipe (6) is in communication with the liquid inlet port (24a), and the liquid inlet connecting pipe (6) is hermetically connected to the bottom plate (2) on which the liquid inlet port (24a) is provided; The inside of the liquid outflow connection pipe (7) is in communication with the liquid outflow port (24b), and the liquid outflow connection pipe (7) is sealed and connected to the bottom plate (2) on which the liquid outflow port (24b) is provided, 2. The battery case according to claim 1, wherein the inlet connecting pipe (6) and the outlet connecting pipe (7) are used to communicate with corresponding external flow ducts.

12. The battery case according to claim 1, characterized in that the bottom plate (2) is provided with a fifth opening (25a) communicating with the fourth cavity (21a), and the battery case (10) further includes a first closing member (8) closing the fifth opening (25a).

13. A method for manufacturing a battery case, comprising: The battery case (10) is a battery case according to any one of claims 1 to 12, The manufacturing method includes: manufacturing the side plate (1) and the bottom plate (2) connected to each other by an integral molding process; and welding at least two of said bottom plates (2) together by a friction welding process.

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