Method for manufacturing power storage device, and power storage device

Abstract

The invention relates to a method for manufacturing a power storage device and a power storage device. A method for manufacturing a power storage device according to the present disclosure is a method for manufacturing a power storage device having a frame for accommodating an electrical device including a battery module, and a cooler fixed to the frame, the manufacturing method of the electricity storage device comprises the following steps: arranging an aluminum alloy heat insulation member between an aluminum alloy frame and an aluminum alloy cooler in a manner that the aluminum alloy heat insulation member does not overlap with the electric equipment when viewed from the vertical direction of the electricity storage device; and joining the frame and the cooler via a heat insulating member, and joining the frame, the heat insulating member, and the cooler by friction stir welding.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method for manufacturing an electrical storage device and an electrical storage device, for example, to a method for manufacturing an electrical storage device having a frame that houses a battery module and a cooler fixed to the frame, and an electrical storage device. BACKGROUND

[0002] An electrical storage device is equipped with a cooler, for example, in order to cool a battery module. For example, the electrical storage device of U.S. Patent Application Publication No. 2023 / 0100022 is configured such that a cooler is joined to a lower end portion of a frame that houses a battery module.

[0003] The present applicant has found the following problem. In the electrical storage device of U.S. Patent Application Publication No. 2023 / 0100022, since the cooler is directly joined to the frame, the cold energy of the cooler can escape to the frame. For example, it is sometimes not possible to cool a battery module and the like inside the electrical storage device well with the cooler. SUMMARY

[0004] The present disclosure was completed in view of such a problem, and aims to achieve a method for manufacturing an electrical storage device and an electrical storage device that can cool a battery module and the like inside the electrical storage device well with a cooler.

[0005] The method for manufacturing an electrical storage device of an aspect of the present disclosure is a method for manufacturing an electrical storage device having a frame that houses an electrical device including a battery module and a cooler fixed to the frame,

[0006] The method for manufacturing an electrical storage device includes the following steps:

[0007] arranging a heat insulating member made of an aluminum alloy between the frame made of an aluminum alloy and the cooler made of an aluminum alloy in such a manner as not to overlap the electrical device when viewed in a vertical direction of the electrical storage device; and

[0008] joining the frame and the cooler via the heat insulating member,

[0009] joining the frame, the heat insulating member, and the cooler by friction stir joining.

[0010] The electrical storage device of an aspect of the present disclosure has a frame that houses an electrical device including a battery module and a cooler fixed to the frame,

[0011] a heat insulating member is arranged between the frame and the cooler in such a manner as not to overlap the electrical device when viewed in a vertical direction of the electrical storage device.

[0012] In the power storage device described above, it is preferable that the frame be made of an aluminum alloy, and the thermal insulation member have a thermal conductivity lower than that of the aluminum alloy forming the frame.

[0013] In the power storage device described above, it is preferable that the thermal conductivity of the thermal insulation member be lower than that of an A6061 aluminum alloy.

[0014] In the power storage device described above, it is preferable that the frame include a frame portion having an open upper side and an open lower side, and the cooler cover the open lower side of the frame, the cooler and the frame forming a housing that accommodates the electrical device.

[0015] According to the present disclosure, it is possible to achieve a manufacturing method of a power storage device and a power storage device that can cool a battery module or the like inside the power storage device using a cooler. BRIEF DESCRIPTION OF DRAWINGS

[0016] Features, advantages, and technical and industrial significance of exemplary embodiments of the present application will be described below with reference to the accompanying drawings, wherein the same reference numerals in different drawings denote the same or similar components, and wherein:

[0017] Figure 1 is an exploded view of a power storage device of an embodiment, which is simplified.

[0018] Figure 2 is a partial cross-sectional view showing the positional relationship of a frame, a thermal insulation member, and a cooler of a housing in a power storage device of an embodiment.

[0019] Figure 3 is a partial cross-sectional view showing a case where an end portion of a frame on the Z-axis side is joined to a peripheral edge portion of a cooler via a thermal insulation member in a power storage device of an embodiment.

[0020] Figure 4 is a cross-sectional view showing the positional relationship of a frame and a cooler of a housing in a power storage device of a comparative example. DETAILED DESCRIPTION

[0021] Hereinafter, with reference to the drawings, a specific embodiment to which the present disclosure is applied will be described in detail. However, the present disclosure is not limited to the following embodiment. In addition, the following description and drawings are appropriately simplified in order to make the description clear.

[0022] First, the structure of the power storage device of the present embodiment will be described. Figure 1 is an exploded view of a power storage device of the present embodiment, which is simplified. Figure 2 is a partial cross-sectional view showing the positional relationship of a frame, a thermal insulation member, and a cooler of a housing in a power storage device of the present embodiment. Furthermore, in Figure 1In this simplified representation, the thermal insulation components are omitted.

[0023] In the following explanation, a three-dimensional (XYZ) coordinate system will be used for clarity. For example, the X-axis + side represents the front of the energy storage device, the X-axis - side represents the rear of the energy storage device, the Y-axis + side represents the left side of the energy storage device, the Y-axis - side represents the right side of the energy storage device, the Z-axis + side represents the top of the energy storage device, and the Z-axis - side represents the bottom of the energy storage device.

[0024] The energy storage device 1 is suitable, for example, for use as an energy storage device mounted in a vehicle, energy storage system, etc. Figure 1 and Figure 2 As shown, the energy storage device 1 includes, for example, a battery module 2, a cooler 3, a housing 4, and a heat insulation component 5.

[0025] Battery module 2 is formed, for example, by electrically connecting battery cells stacked along the Y-axis direction. Figure 1 As shown, the battery modules 2 are arranged at intervals along the X-axis. Furthermore, the battery modules 2 are not limited to lithium-ion batteries; they can also be nickel-metal hydride batteries, nickel-cadmium batteries, or all-solid-state batteries, etc.

[0026] For example, Figure 1 and Figure 2 As shown, the cooler 3 is generally flat and is configured to have a flow path inside for the refrigerant (e.g., coolant) to flow through. The cooler 3 can be formed, for example, by joining two plates together. The cooler 3 can be formed, for example, from A3003 aluminum alloy.

[0027] For example, Figure 1 As shown, the housing 4 includes an upper housing 4a and a lower housing 4b. The upper housing 4a covers, for example, the opening on the Z-axis+ side of the lower housing 4b. The lower housing 4b includes, for example, a frame 4c and a cooler 3.

[0028] For example, Figure 1 As shown, frame 4c has a frame portion capable of accommodating battery module 2, and can be formed, for example, from an aluminum alloy such as A6061 aluminum alloy. In this case, for example... Figure 2 As shown, frame 4c can be an extruded or die-cast part with a hollow rectangular shape.

[0029] This allows for a lighter energy storage device 1. The periphery of the upper housing 4a is fixed to the Z-axis+ side end of the frame 4c. The cooler 3 covers the open portion on the Z-axis-side of the frame 4c. The battery module 2 is housed inside this housing 4.

[0030] like Figure 2As shown, the heat insulation member 5 is disposed between the Z-axis end of the frame 4c and the periphery of the cooler 3. That is, the heat insulation member 5 is configured so as not to overlap with the battery module 2 when viewed from the Z-axis direction. The heat insulation member 5 can be formed, for example, from an aluminum alloy such as A380 aluminum alloy, which has a lower thermal conductivity than the aluminum alloy forming the housing 4.

[0031] The Z-axis end of the frame 4c is joined to the periphery of the cooler 3 via a heat-insulating member 5. This prevents the escape of cold energy from the cooler 3 to the frame 4c, and allows the cooler 3 to effectively cool the battery module 2.

[0032] Next, the process of manufacturing the energy storage device 1 of this embodiment will be described. Figure 3 This is a partial cross-sectional view showing the case where the Z-axis side end of the frame is joined to the periphery of the cooler via a heat insulation member in the energy storage device of this embodiment. First, as... Figure 3 As shown, a heat insulation member 5 is disposed between the Z-axis end of the frame 4c and the periphery of the cooler 3.

[0033] Next, as Figure 3 As shown, while rotating the tool 6, the probe 6a of the tool 6 is inserted into the periphery of the frame 4c, the heat insulation member 5, and the cooler 3. The Z-axis end of the frame 4c is frictionally stirred and joined to the periphery of the cooler 3 via the heat insulation member 5.

[0034] Next, the energy storage device 1 can be manufactured by housing the battery module 2 in the lower housing 4b formed by the frame 4c and the cooler 3 and covering the opening on the Z-axis+ side of the lower housing 4b with the upper housing 4a.

[0035] Here, Figure 4 This is a cross-sectional view showing the configuration relationship between the housing frame and the cooler in the comparative example energy storage device. The comparative example energy storage device uses A6061 aluminum alloy to form the frame 14c constituting the housing 14. The cooler 13 is formed using A3003 aluminum alloy, and the clamping member 15 is formed using A6061 aluminum alloy. The frame 14c's Z-axis side end is joined to the periphery of the cooler 13 via the clamping member 15.

[0036] At this point, the thickness of the clamping member 15 in the Z-axis direction is set to 10 mm, and the clamping member 15 is integrally formed with the frame 14c. Furthermore, the contact area between the frame 14c (i.e., the clamping member 15) and the cooler 13 is set to 1 m². 2 Additionally, the temperature of frame 14c is set to 30°C, and the temperature of cooler 13 is set to 10°C. In this case, the heat transfer from cooler 13 to frame 14c is 3.6 × 10⁻⁶. 5 W.

[0037] On the other hand, in this embodiment, the energy storage device 1 uses A6061 aluminum alloy to form the frame 4c constituting the housing 4. The cooler 3 is formed using A3003 aluminum alloy. The heat insulation member 5 is formed using A380 aluminum alloy. The frame 4c's Z-axis side end is joined to the periphery of the cooler 3 via the heat insulation member 5.

[0038] At this point, the thickness of the heat insulation component 5 in the Z-axis direction is set to 10mm. Furthermore, the contact area between the cooler 3 and the heat insulation component 5 is set to 1m². 2 Additionally, the temperature of frame 4c is set to 30°C, and the temperature of cooler 3 is set to 10°C. Under these conditions, the heat transfer from cooler 3 to frame 4c is 1.92 × 10⁻⁶. 5 W.

[0039] Thus, in the manufacturing method and the energy storage device 1 of this embodiment, a heat insulation member 5 is arranged between the frame 4c and the cooler 3 in such a way that it does not overlap with the battery module 2 when viewed from the Z-axis direction. That is, it is not a structure like that of a typical energy storage device, where the cold energy of the cooler is transferred to the battery module via the frame and the battery module is cooled. Therefore, the escape of cold energy from the cooler 3 to the frame 4c can be suppressed, and the battery module 2 can be effectively cooled by the cooler 3.

[0040] Furthermore, in the manufacturing method and the energy storage device 1 of this embodiment, when the frame 4c, the heat insulation member 5, and the cooler 3 are joined by friction stirring, they can be joined in one step, which can improve productivity. In addition, compared with the case where the frame 4c, the heat insulation member 5, and the cooler 3 are joined by a conventional welding method, the airtightness of the joint can be ensured.

[0041] Furthermore, in this embodiment, the frame 4c, cooler 3, and heat insulation component 5 are made of aluminum alloy. However, as long as the thermal conductivity of the heat insulation component 5 is lower than that of the frame 4c, the material of each component is not limited.

[0042] Furthermore, the frame 4c in this embodiment is an open structure on the Z-axis side, but it can also be a structure that is covered at the bottom. Additionally, the frame 4c can also be a structure in which the frame portion is reinforced using reinforcing members or the like.

[0043] Furthermore, the configuration of the heat insulation member 5 is not limited, as long as the heat insulation member 5 is configured between the frame 4c and the cooler 3 in such a way that it does not overlap with the electrical equipment containing the battery module 2 when viewed from the Z-axis direction.

[0044] In addition, in this embodiment, the battery module 2 is cooled by the cooler 3, but the object cooled by the cooler 3 may be, for example, a control device that controls the battery module 2, which is a representative example of electrical equipment.

[0045] This disclosure is not limited to the above-described embodiments, and appropriate changes can be made without departing from the spirit of the invention.

Claims

1. A method for manufacturing an energy storage device, the energy storage device comprising: a frame housing an electrical device including a battery module; and a cooler fixed to the frame, wherein, The manufacturing method of the energy storage device includes the following steps: An aluminum alloy thermal insulation member is positioned between the aluminum alloy frame and the aluminum alloy cooler in a manner that does not overlap with the electrical equipment when viewed from above or below the energy storage device; and The frame is joined to the cooler via the thermal insulation member. The frame, the insulation component, and the cooler are joined together by friction stirring.

2. An energy storage device, wherein, The energy storage device includes: a frame that houses electrical equipment including a battery module; and a cooler fixed to the frame. The thermal insulation component is arranged between the frame and the cooler in such a way that it does not overlap with the electrical equipment when viewed from the vertical direction of the energy storage device.

3. The energy storage device according to claim 2, wherein, The frame is made of aluminum alloy. The thermal insulation component has a lower thermal conductivity than the aluminum alloy forming the frame.

4. The energy storage device according to claim 3, wherein, The thermal conductivity of the insulation component is lower than that of A6061 aluminum alloy.

5. The energy storage device according to any one of claims 2 to 4, wherein, The frame has open frame portions on its upper and lower sides. The cooler covers the opening on the lower side of the frame. The cooler and the frame are used to form a housing for the electrical equipment.

Images