Manufacturing method of power storage device

Abstract

To provide a manufacturing method of a power storage device capable of suppressing cracks in a cooler that may occur when spreading a thermally conductive material placed between the bottom of a lower case and a cooler.SOLUTION: A manufacturing method of a power storage device includes: a placement step of placing a thermal conductive material between the bottom and a cooler so as to come into contact with each of the lower case including the bottom part with the outer surface and the cooler arranged facing the outer surface; and a suction step of, after the placement step, spreading the thermal conductive material by sucking the air in the space between the bottom, cooler and thermal conductive material using a suction device.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] An electric power storage device mounted on a vehicle has, for example, a housing case that houses an electric power storage module. Patent Document 1 discloses a battery case as an example of such a housing case.

[0003] For example, the battery case described in Patent Document 1 is a case body having a case bottom wall portion and a case side wall portion connected to the peripheral portion of the case bottom wall portion and defining, together with the case bottom wall portion, a battery storage portion for storing a battery module, the case bottom wall portion having an opening that connects the battery storage portion to the outside of the case body, a cooler arranged to face the outside of the case bottom wall portion, and an insulating sheet arranged between the cooler and the case bottom wall portion and covering the opening. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-168640 Summary of the Invention [Problem to be solved by the invention]

[0005] The cooler, which is arranged to face the outer surface of the bottom (case bottom wall) of the lower case (case main body) that constitutes the storage case (battery case), has the function of cooling the storage module (battery module) placed on the bottom.

[0006] The insulating sheet described in Patent Document 1 has thermal conductivity and can function as a thermal conductor for transferring heat from the power storage module to the cooler. It is desirable to thermally adhere the bottom of the lower case to the cooler via such a thermal conductor. The thermal conductor is expanded between the bottom of the lower case and the cooler, thereby improving the adhesion of the cooler to the bottom.

[0007] Therefore, for example, it is conceivable to arrange a thermally conductive material so that it abuts against the bottom of the lower case and the cooler, and then use a roller device to spread the thermally conductive material arranged between the bottom and the cooler. When using a roller device, the rollers of the roller device are rotated and moved to press the cooler toward the bottom from the side opposite to the side where the thermally conductive material is arranged, thereby spreading the thermally conductive material arranged between the bottom and the cooler. However, this method has a problem in that local stress concentration is likely to occur in the cooler due to uneven contact of the rollers caused by differences in the thickness of the thermally conductive material before spreading and the shape of the cooler, which may cause the cooler to crack.

[0008] The present disclosure has been made to solve such problems, and aims to provide a method for manufacturing an energy storage device that can suppress cracks in the cooler that may occur when spreading out the thermally conductive material arranged between the bottom of the lower case and the cooler. [Means for solving the problem]

[0009] A manufacturing method for an energy storage device according to one embodiment includes an arrangement step of arranging a thermally conductive material between a lower case including a bottom having an outer surface and a cooler arranged to face the outer surface so that the thermally conductive material abuts against each of the bottom and the cooler, and after the arrangement step, a suction step of using a suction device to suck air from the space between the bottom, the cooler, and the thermally conductive material, thereby expanding the thermally conductive material. [Effects of the Invention]

[0010] The present disclosure provides a manufacturing method for an energy storage device that can suppress cracks in the cooler that may occur when spreading out the thermally conductive material arranged between the bottom of the lower case and the cooler. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is an exploded perspective view illustrating an example of a power storage device. [Figure 2] 4 is a flowchart showing a method for manufacturing the electricity storage device according to the first embodiment. [Figure 3] FIG. 10 is a perspective view for explaining an arrangement step. [Figure 4] 10A and 10B are a perspective view and a partial cross-sectional view for explaining a suction step. [Figure 5] 10A and 10B are a perspective view and a partial cross-sectional view illustrating a pressing step in a manufacturing method for an electricity storage device according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Embodiment 1 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited to the following embodiments. Furthermore, for clarity of explanation, the following description and drawings have been simplified as appropriate. What is shown in the drawings is only a part of the whole, and in reality, many other configurations not shown are included. In the following description, the same or equivalent elements are given the same reference numerals, and redundant explanations will be omitted.

[0013] Fig. 1 is an exploded perspective view showing an example of an electricity storage device. The electricity storage device 1 shown in Fig. 1 is mounted on an electric vehicle, such as a hybrid vehicle that can run using the power of at least one of a motor and an engine, or an electric vehicle that runs on driving force obtained from electrical energy. As shown in Fig. 1, the electricity storage device 1 has a plurality of electricity storage modules 10, a housing case 20, a cooler 30, a thermally conductive material 40, a share panel 50, and an inner thermally conductive layer 60.

[0014] Each of the plurality of power storage modules 10 includes a first power storage stack 11 and a second power storage stack 12. Each of the first power storage stack 11 and the second power storage stack 12 includes a plurality of power storage cells 13 stacked in a first direction (DR1 direction). Note that the first direction is, for example, parallel to the width direction of the vehicle when the power storage device 1 is mounted on the vehicle.

[0015] The storage cell 13 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The storage cell 13 has, for example, a rectangular shape. The storage cell 13 may use a liquid electrolyte or a solid electrolyte. The storage cell 13 may also be a unit capacitor configured to be able to store electricity.

[0016] The plurality of power storage modules 10 are arranged to be spaced apart in a second direction (DR2 direction) perpendicular to the first direction. The first power storage stack 11 and the second power storage stack 12 included in each power storage module 10 are arranged to be aligned in the second direction. Note that the second direction is, for example, parallel to the front-to-rear direction of the vehicle when the power storage device 1 is mounted on the vehicle.

[0017] The storage case 20 houses a plurality of power storage modules 10. The storage case 20 includes an upper case 21 and a lower case 22. The upper case 21 has a generally box-like shape that is open downward. The upper case 21 is made of a metal material. Alternatively, to reduce weight, the upper case 21 may be made of a resin material.

[0018] The lower case 22 has a generally box-like shape that opens upward. The lower case 22 is made of a metal material. The lower case 22 preferably has good thermal conductivity. The lower case 22 has a bottom 23 and sidewalls 24.

[0019] The bottom 23 is disposed below the plurality of energy storage modules 10. The plurality of energy storage modules 10 are placed on the bottom 23 via an inner thermally conductive layer 60. The bottom 23 has an inner surface 23a and an outer surface 23b that face each other. The inner surface 23a faces the plurality of energy storage modules 10. The outer surface 23b faces the cooler 30 via a thermally conductive material 40.

[0020] The bottom portion 23 is provided with a plurality of bracket portions 25 that protrude downward from the bottom portion 23. The plurality of bracket portions 25 are arranged so as to be spaced apart in the second direction. The plurality of bracket portions 25 are provided so as to fit into gaps between adjacent cooling portions 31. Each of the plurality of bracket portions 25 is provided so as to cover a portion of the bottom portion 23. The plurality of bracket portions 25 extend along the first direction.

[0021] The side wall portion 24 is an outer peripheral wall that extends in the vertical direction from the outer edge of the bottom portion 23. A flange portion provided along the outer periphery of the lower case 22 is fastened to a flange portion provided along the outer periphery of the upper case 21 by fastening means such as bolts.

[0022] The cooler 30 is a device for cooling the multiple power storage modules 10. A refrigerant flow path through which a refrigerant flows is provided inside the cooler 30. One end of the refrigerant flow path is connected to a refrigerant introduction section 61, and the other end is connected to a refrigerant discharge section 62. The refrigerant introduced into the refrigerant flow path from the refrigerant introduction section 61 cools the multiple power storage modules 10 and is discharged from the refrigerant discharge section 62.

[0023] The cooler 30 is disposed below the bottom 23. The cooler 30 is made of a metal material such as aluminum. The cooler 30 has a facing surface 30a and a non-facing surface 30b that face each other. The facing surface 30a is the surface of the cooler 30 that faces the bottom 23. The non-facing surface 30b is the surface of the cooler 30 opposite to the facing surface 30a.

[0024] The cooler 30 includes a plurality of cooling sections 31, a holding section 32, a front section 33, and a rear section 34. The plurality of cooling sections 31 are arranged to be spaced apart in the second direction. The plurality of cooling sections 31 are arranged at positions corresponding to the plurality of power storage modules 10. The plurality of cooling sections 31 are provided in accordance with the number of power storage modules 10. Each of the plurality of cooling sections 31 includes a first cooling section 31a and a second cooling section 31b.

[0025] The first cooling section 31a is disposed below the bottom section 23 so as to sandwich the bottom section 23 between the first cooling section 31a and the first power storage stack 11. The first cooling section 31a extends along the first direction.

[0026] The second cooling section 31b is disposed below the bottom section 23 so as to sandwich the bottom section 23 between the second cooling section 31b and the second power storage stack 12. The second cooling section 31b extends along the first direction.

[0027] The holding portion 32 holds the multiple cooling portions 31. The holding portion 32 includes a first holding portion 32a and a second holding portion 32b. The first holding portion 32a extends along the second direction. The first holding portion 32a holds one end of the first cooling portion 31a and one end of the second cooling portion 31b in the first direction in each of the multiple cooling portions 31.

[0028] The second holding portion 32b is disposed at an interval from the first holding portion 32a in the first direction. The second holding portion 32b extends along the second direction. In each of the multiple cooling portions 31, the second holding portion 32b holds the other ends of the first cooling portion 31a and the second cooling portion 31b in the first direction.

[0029] The front portion 33 is located on one side of the cooler 30 in the second direction. The front portion 33 is provided to connect the first holding portion 32a and the second holding portion 32b on one side in the second direction. The front portion 33 is provided to protrude from one end of the first holding portion 32a and the second holding portion 32b in the second direction to one side in the second direction. The front portion 33 has a substantially C-shape. A refrigerant inlet portion 61 and a refrigerant outlet portion 62 are provided in the front portion 33.

[0030] The rear portion 34 is located on the other side of the cooler 30 in the second direction. The rear portion 34 is provided to connect the first holding portion 32a and the second holding portion 32b on the other side in the second direction. The rear portion 34 extends along the first direction.

[0031] The cooler 30 has a hole 30c surrounded by the first cooling section 31a, the second cooling section 31b, the first holding section 32a, and the second holding section 32b. The hole 30c penetrates the cooler 30 in its thickness direction. The cooler 30 has a plurality of holes 30c corresponding to the number of cooling sections 31. The plurality of holes 30c are arranged at positions corresponding to the plurality of spaces S (see FIG. 3). Each of the plurality of holes 30c is provided so as to communicate with the corresponding space S.

[0032] The thermally conductive material 40 is disposed between the outer surface 23b and the cooler 30. Specifically, the multiple power storage modules 10 are cooled by the cooler 30 via the thermally conductive material 40, the bottom 23, and the inner thermally conductive layer 60. The thermally conductive material 40 also functions as an adhesive layer that bonds the bottom 23 and the cooler 30 together. As the thermally conductive material 40, for example, an adhesive containing a silicone resin, an acrylic resin, a urethane resin, an epoxy resin, or the like can be used.

[0033] The shear panel 50 is disposed so as to cover the cooler 30 from below. The shear panel 50 protects the cooler 30 and also prevents the cooler 30 from being exposed to water. The shear panel 50 is made of a metal material.

[0034] The inner thermally conductive layer 60 is disposed between each power storage module 10 and the inner surface 23a. More specifically, the inner thermally conductive layer 60 is disposed between the first power storage stack 11 and the second power storage stack 12 included in each power storage module 10 and the inner surface 23a. The inner thermally conductive layer 60 also functions as an adhesive layer, and adhesively fixes each power storage module 10 to the bottom 23. The multiple power storage modules 10 are in thermal contact with the inner surface 23a via the inner thermally conductive layer 60.

[0035] The inner thermally conductive layer 60 is made of a thermally conductive resin material. For example, an adhesive containing a silicone resin, an acrylic resin, a urethane resin, or an epoxy resin can be used as the inner thermally conductive layer 60.

[0036] The above-described energy storage device 1 can be manufactured by a method for manufacturing the energy storage device 1 according to the first embodiment (hereinafter, may be referred to as "the present manufacturing method") shown in Figures 2 to 4. Figure 2 is a flowchart showing the method for manufacturing the energy storage device according to the first embodiment. As shown in Figure 2, the present manufacturing method includes a preparation step (step S1), a placement step (step S2), a suction step (step S3), and an attachment step (step S4).

[0037] First, the preparation process includes a lower case preparation process for preparing the lower case 22 and a cooler preparation process for preparing the cooler 30. In the lower case preparation process, the lower case 22 is prepared, which includes a bottom 23 having an outer surface 23b. In the cooler preparation process, the cooler 30 is prepared, which includes at least one cooling section 31 and a holding section 32. Here, the at least one cooling section 31 includes a first cooling section 31a and a second cooling section 31b extending in a first direction and spaced apart from each other in a second direction perpendicular to the first direction. Furthermore, the holding section 32 includes a first holding section 32a and a second holding section 32b extending in the second direction and spaced apart from each other in the first direction, and which hold the at least one cooling section 31.

[0038] Next, the arrangement step will be described in detail with reference to Fig. 3. Fig. 3 is a perspective view for explaining the arrangement step. Fig. 3 shows the lower case 22, the thermally conductive material 40, and the cooler 30 as viewed from the bottom 23 side.

[0039] As shown in FIG. 3, the placement process is a process of placing a thermally conductive material 40 between the lower case 22 including a bottom 23 having an outer surface 23b and the cooler 30 so as to abut against each of the lower case 22 and the cooler 30 arranged opposite the outer surface 23b.

[0040] In the case of the thermally conductive material 40 having a spreadable property such as a liquid, gel, or putty state, in the disposing step, when disposing the thermally conductive material 40 between the bottom portion 23 and the cooler 30, it is preferable to dispose the lower case 22 so that the outer surface 23b faces upward as shown in the upper side of Fig. 3, and then apply the thermally conductive material 40 to the outer surface 23b as shown in the center of Fig. 3. At this time, the thermally conductive material 40 is applied to each of the outer surfaces 23b of the portions corresponding to the plurality of cooling portions 31, the portions corresponding to the holding portion 32, and the portions corresponding to the front portion 33.

[0041] In the case of the thermally conductive material 40 having a non-coatable form, such as a sheet, in the disposing step, when disposing the thermally conductive material 40 between the bottom portion 23 and the cooler 30, the lower case 22 may be disposed so that the outer surface 23b faces upward, as shown in the upper part of FIG. 3, and then the thermally conductive material 40 may be placed on the outer surface 23b, as shown in the center of FIG. 3. At this time, the thermally conductive material 40 is placed on each of the portions of the outer surface 23b corresponding to the plurality of cooling portions 31, the portions corresponding to the holding portion 32, and the portions corresponding to the front portion 33. In this way, by applying or placing the thermally conductive material 40 on the outer surface 23b, the thermally conductive material 40 is formed on the outer surface 23b.

[0042] 3, in the arrangement step, the cooler 30 is arranged above the bottom 23 so that the opposing surface 30a faces the outer surface 23b on which the thermally conductive material 40 is formed, and then the cooler 30 is moved toward the bottom 23. As a result, the thermally conductive material 40 is arranged between the bottom 23 and the cooler 30 so as to abut against both the lower case 22 including the bottom 23 having the outer surface 23b and the cooler 30 arranged to face the outer surface 23b.

[0043] Next, the suction step will be described in detail with reference to Fig. 4. Fig. 4 is a perspective view and a partial cross-sectional view for explaining the suction step. The upper perspective view of Fig. 4 shows the lower case 22 and the cooler 30 as viewed from the bottom 23 side. The lower partial cross-sectional view of Fig. 4 shows a cross section of the periphery of the cooling section 31 (first cooling section 31a and second cooling section 31b) indicated by the dashed line in the perspective view of Fig. 4 as viewed from the first direction.

[0044] As shown in FIG. 4, the suction process is a process in which, after the placement process, a suction device 70 is used to suction air from the space S between the bottom 23, the cooler 30, and the thermally conductive material 40, thereby expanding the thermally conductive material 40.

[0045] The suction device 70 has, for example, a vacuum pump (not shown) as a vacuum generating means for generating a vacuum, and a suction unit 71 capable of sealing the space S. The suction device 70 shown in Fig. 3 has a plurality of suction units 71 arranged at positions corresponding to the plurality of holes 30c. The plurality of suction units 71 are provided in accordance with the number of the plurality of holes 30c.

[0046] The suction device 70 is configured to suck air from the plurality of spaces S as shown by the arrows in Fig. 4 when a vacuum pump connected to the plurality of suction units 71 is driven with the plurality of suction units 71 attached to the cooler 30. In this manner, the suction device 70 performs vacuum drawing to suck the air from the spaces S, thereby creating a vacuum in the spaces S. Therefore, according to this manufacturing method, the suction process can be performed in each of the plurality of manufacturing lines arranged in parallel, simply by providing the suction device 70 in the manufacturing line.

[0047] When the cooler 30 has holes 30c, the suction device 70 preferably sucks air from the space S through the holes 30c. By using the holes 30c for vacuuming with the suction device 70, the heat conductive material 40 can be spread using the suction device 70 without increasing the weight of the cooler 30, as compared to when the cooler 30 is provided with components for vacuuming.

[0048] When the plurality of spaces S are evacuated by the suction device 70, stress acts on the bottom 23 and the cooler 30 to bring them closer to each other, and the bottom 23 and the cooler 30 press the thermally conductive material 40 so that it is compressed in the thickness direction. In this way, the thermally conductive material 40 can be spread. The spread thermally conductive material 40 is formed over a wide area, and therefore the adhesion of the cooler 30 to the bottom 23 can be improved.

[0049] The thickness and degree of spread of the thermally conductive material 40 disposed between the bottom 23 and the cooler 30 can be controlled by adjusting at least one of the following conditions: the temperature of the thermally conductive material 40, the degree of vacuum in the sealed space S, the time for which the vacuum is maintained, and the air suction speed. Therefore, according to this manufacturing method in which the suction device 70 is used to spread the thermally conductive material 40, the thickness and degree of spread of the thermally conductive material 40 can be guaranteed by the above-mentioned conditions, regardless of the process capacity of the suction step. Note that the temperature of the thermally conductive material 40, the degree of vacuum, the time for which the vacuum is maintained, and the air suction speed can be set based on the physical properties of the thermally conductive material 40, such as its viscosity, so that the thermally conductive material 40 has a predetermined thickness and a predetermined degree of spread after the suction step.

[0050] Furthermore, the suction unit 71 preferably has a tip 72 including an adsorption surface 72a that is adsorbed to the non-opposing surface 30b. The adsorption surface 72a of such tip 72 is adsorbed to each of the non-opposing surfaces 30b of the first cooling unit 31a, the second cooling unit 31b, the first holding unit 32a, and the second holding unit 32b that surround the hole 30c. The adsorption surface 72a is adsorbed to the non-opposing surface 30b, thereby improving the adhesion of the suction unit 71 to the cooler 30, and therefore the suction unit 71 can efficiently suck in air from the sealed space S.

[0051] Furthermore, it is preferable that the tip 72 of the suction part 71 elastically deforms when the adsorption surface 72a is pressed against the non-opposing surface 30b. Such suction part 71 is a so-called suction cup, with at least the tip 72 made of resin. When drawing a vacuum, the adsorption surface 72a of the elastically deforming tip 72 of the suction part 71 descends while following the non-opposing surface 30b of the cooler 30, so that the thermally conductive material 40 can be spread to a predetermined thickness while suppressing the load applied from the suction part 71 to the cooler 30.

[0052] The attachment process includes a shear panel attachment process of attaching the shear panels 50 and an energy storage module attachment process of attaching the energy storage modules 10. In the shear panel attachment process, after the suction process, the shear panels 50 are attached to the bottom 23 so as to cover the coolers 30 attached to the lower case 22. In the energy storage module attachment process, the lower case 22 to which the shear panels 50 and coolers 30 are attached is inverted so that the inner surface 23a of the bottom 23 faces upward. Next, an inner thermally conductive layer 60 is provided on the inner surface 23a of the parts corresponding to each cooling section 31, and the energy storage module 10 is attached to the lower case 22 so as to sandwich the inner thermally conductive layer 60 between the bottom 23 and the energy storage module 10.

[0053] Through the steps described above, the electricity storage device 1 shown in FIG. 1 can be manufactured.

[0054] Here, problems with a manufacturing method for an electricity storage device according to a comparative example (hereinafter, may be referred to as a "manufacturing method according to a comparative example") will be described with reference to Fig. 5. Fig. 5 is a perspective view and a partial cross-sectional view for explaining the pressing step of the manufacturing method for an electricity storage device according to the comparative example. The upper perspective view of Fig. 5 shows the lower case 22 and the cooler 30 as viewed from the bottom 23 side. The lower partial cross-sectional view of Fig. 5 shows a cross section of the periphery of the cooling section 31 (first cooling section 31a and second cooling section 31b) indicated by the dashed line in the perspective view of Fig. 5, as viewed from a first direction.

[0055] The manufacturing method according to the comparative example includes the arrangement step shown in Fig. 3. After the arrangement step, the manufacturing method according to the comparative example includes a pressing step of pressing the cooler 30 toward the bottom 23 using a roller device 80 to spread the thermally conductive material 40, as shown in Fig. 5.

[0056] The roller device 80 includes a plurality of rollers 81 and a shaft portion (not shown) that rotatably supports the plurality of rollers 81. The plurality of rollers 81 are disposed at positions corresponding to the first cooling portion 31a and the second cooling portion 31b included in each cooling portion 31. In the pressing process, the rollers 81 are rotated and moved from one end side to the other end side of each cooling portion 31 (the first cooling portion 31a and the second cooling portion 31b) as indicated by the arrows in FIG. 5, thereby pressing the cooler 30 toward the bottom portion 23 from the non-facing surface 30b side. At this time, each roller 81 moves while rotating on the non-facing surface 30b of each of the first cooling portion 31a and the second cooling portion 31b. In this manner, the thermally conductive material 40 can be spread.

[0057] In such a pressing process, as shown within the dashed double-dashed line in Figure 5, localized stress concentration is likely to occur in the cooler 30 due to uneven contact of the roller 81 caused by differences in thickness of the thermally conductive material 40 before being pressed out and the shape of the cooler 30, which may result in the cooler 30 cracking.

[0058] In contrast, as explained using Figures 2 to 4, the present manufacturing method includes an arrangement step of arranging a thermally conductive material 40 between the lower case 22 including a bottom 23 having an outer surface 23b and the cooler 30 so that the thermally conductive material 40 abuts against each of the bottom 23 and the cooler 30 arranged opposite the outer surface 23b, and a suction step of, after the arrangement step, using a suction device 70 to suck air from the space S between the bottom 23, the cooler 30 and the thermally conductive material 40, thereby expanding the thermally conductive material 40.

[0059] According to this configuration, as shown in Fig. 4, by spreading out the thermally conductive material 40 arranged between the bottom 23 and the cooler 30, the thermally conductive material 40 is formed over a wide area, thereby improving the adhesion of the cooler 30 to the bottom 23. Furthermore, in this manufacturing method, the thermally conductive material 40 is spread out using a suction device 70 that sucks air from the space S, so that local stress concentration that may occur in the cooler 30 can be suppressed, as shown within the dashed dotted line in Fig. 4. Therefore, according to this manufacturing method, it is possible to suppress cracks in the cooler 30 that may occur when spreading out the thermally conductive material 40 arranged between the bottom 23 of the lower case 22 and the cooler 30.

[0060] Furthermore, in this manufacturing method, the cooler 30 has at least one cooling section 31 including a first cooling section 31a and a second cooling section 31b extending in a first direction and arranged at a distance from each other in a second direction perpendicular to the first direction, a holding section 32 extending in the second direction and including a first holding section 32a and a second holding section 32b arranged at a distance from each other in the first direction and holding the at least one cooling section 31, and a hole 30c surrounded by the first cooling section 31a, the second cooling section 31b, the first holding section 32a, and the second holding section 32b, and the suction device 70 sucks air from the space S through the hole 30c.

[0061] According to this configuration, the heat conductive material 40 can be spread out using the suction device 70 without increasing the weight of the cooler 30 or the like.

[0062] Furthermore, in this manufacturing method, the suction device 70 has a vacuum generating means for generating a vacuum and a suction part 71 capable of sealing the space S, and the suction part 71 has a tip part 72 including an adsorption surface 72a that adsorbs to the non-opposing surface 30b opposite to the opposing surface 30a that faces the bottom 23 of the cooler 30.

[0063] With this configuration, the suction device 70 can efficiently suck air from the sealed space S by the suction part 71.

[0064] Furthermore, in this manufacturing method, the tip end 72 of the suction part 71 is elastically deformed by pressing the adsorption surface 72a against the non-opposing surface 30b.

[0065] With this configuration, when drawing a vacuum, the suction part 71 descends while the suction surface 72a of the elastically deforming tip part 72 follows the non-opposing surface 30b of the cooler 30, so that the thermally conductive material 40 can be expanded to a predetermined thickness while suppressing the load applied to the cooler 30 from the suction part 71. Therefore, it is possible to suppress cracks in the cooler 30 that may occur when the thermally conductive material 40 arranged between the bottom part 23 of the lower case 22 and the cooler 30 is expanded.

[0066] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present disclosure. For example, in the above-described embodiment, a vacuum pump is used as the vacuum generating means of the suction device 70, but this is not limited to this. As the vacuum generating means, various pumps that generate vacuum other than a vacuum pump, a vacuum ejector, a vacuum chamber (also called a vacuum reservoir tank or vacuum buffer tank, etc.), etc. can be used.

[0067] Furthermore, in the above embodiment, when forming the thermally conductive material 40, the case where the thermally conductive material 40 is applied or placed on the outer surface 23b of the bottom portion 23 has been described as an example, but the present invention is not limited to this, and the thermally conductive material 40 may be applied or placed on the cooler 30. When applying or placing the thermally conductive material 40 on the cooler 30, the thermally conductive material 40 is applied or placed on the opposing surfaces 30a of each of the plurality of cooling portions 31, the holding portion 32, and the front portion 33.

[0068] Furthermore, in the above embodiment, the cooler 30 is described as being provided with a plurality of cooling sections 31 including the first cooling section 31a and the second cooling section 31b. However, the number of cooling sections 31 provided in the cooler 30 may be one. When there is one cooling section 31, one hole 30c is formed in the cooler 30. When the suction device 70 suctions air from the space S through the hole 30c, the cooler 30 only needs to have at least one cooling section 31 and thus at least one hole 30c. Note that when the cooler 30 is provided with components for vacuuming by the suction device 70, the cooler 30 does not need to have the hole 30c. [Explanation of symbols]

[0069] 1 Energy storage device 10 Energy storage module 11 First storage stack 12 Second storage stack 13 Storage cell 20 Storage case 21 Upper case 22 Lower case 23 Bottom 23a Inner surface 23b Outer surface 24 Side wall portion 25 Bracket portion 30 Cooler 30a Opposing surface 30b Non-opposing surface 30c Hole 31 Cooling section 31a First cooling section 31b Second cooling section 32 Holding part 32a First holding part 32b Second holding part 33 Front section 34 Rear section 40 Thermal Conductive Material 50 Share Panel 60 inner heat conduction layer 61 refrigerant inlet 62 refrigerant outlet 70 Suction device 71 Suction section 72 Tip section 72a Suction surface 80 Roller device 81 Roller S space

Claims

1. a disposing step of disposing a thermally conductive material between a lower case including a bottom having an outer surface and a cooler disposed so as to face the outer surface, the thermally conductive material being in contact with the bottom and the cooler; a suction step of using a suction device to suction air in spaces between the bottom, the cooler, and the thermally conductive material, thereby spreading the thermally conductive material; A method for manufacturing an electricity storage device having the above structure.

2. The cooler is at least one cooling unit including a first cooling unit and a second cooling unit extending in a first direction and spaced apart from each other in a second direction perpendicular to the first direction; a holding portion including a first holding portion and a second holding portion extending in the second direction and spaced apart from each other in the first direction, the first holding portion and the second holding portion holding the at least one cooling portion; a hole surrounded by the first cooling portion, the second cooling portion, the first holding portion, and the second holding portion, The suction device is The method for manufacturing an electricity storage device according to claim 1 , wherein the air in the space is sucked through the hole.

3. The suction device is a vacuum generating means for generating a vacuum; a suction part capable of sealing the space, The suction unit is The method for manufacturing an electricity storage device according to claim 1 , wherein the cooler has a tip portion including an adsorption surface that adsorbs to a non-facing surface on the opposite side to a facing surface that faces the bottom.

4. The suction unit is The tip portion is elastically deformed by pressing the adsorption surface against the non-opposing surface. The method for manufacturing the electricity storage device according to claim 3 .

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