Power storage module

Abstract

To provide a power storage module which eases an impact applied to cylindrical power storage cells.SOLUTION: A power storage module 100 includes: a plurality of power storage cells (cylindrical power storage cells) 10; pillar parts 20 which are arranged so as to be surrounded by the power storage cells 10; and a case 30 which houses the power storage cells 10. The pillar parts 20 extend along a Z direction. A length L1 of the pillar part 20 in the Z direction (an axial direction) is larger than a length L2 of each of the power storage cells 10 in the Z direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an energy storage module. [Background technology]

[0002] Japanese Patent No. 4921629 (Patent Document 1) discloses a battery pack structure in which a plurality of cylindrical battery modules are arranged. Both axial ends of each of the plurality of battery modules are fixed by a battery holder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4921629 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned Patent Document 1, both axial ends of each of the multiple battery modules are fixed by the battery holder, so that any impact applied to the battery holder is directly transmitted to the battery modules. It is desirable to mitigate the impact on the battery modules (cylindrical storage cells).

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide an energy storage module capable of mitigating impact to cylindrical energy storage cells. [Means for solving the problem]

[0006] An energy storage module according to one aspect of the present disclosure includes a plurality of cylindrical energy storage cells arranged so that their axial directions are substantially parallel to one another, at least one pillar portion arranged so as to be surrounded by the plurality of cylindrical energy storage cells, and a case that houses the plurality of cylindrical energy storage cells. The pillar portion extends along the axial direction. The length of the pillar portion in the axial direction is greater than the length of each of the plurality of cylindrical energy storage cells in the axial direction.

[0007] In the energy storage module according to one aspect of the present disclosure, as described above, the length of the column portion in the axial direction is greater than the length of each of the plurality of cylindrical energy storage cells in the axial direction. This allows at least one of the ends of the cylindrical energy storage cells in the axial direction to be separated from the case. As a result, compared to a case in which both ends of the cylindrical energy storage cells in the axial direction are fixed by the case, it is possible to suppress the transmission of an impact applied to the case to the cylindrical energy storage cells. This makes it possible to mitigate the impact on the cylindrical energy storage cells.

[0008] In the energy storage module according to the above aspect, the column portion preferably has an internal flow path extending in the axial direction and through which a refrigerant flows, or a hollow portion filled with a fire extinguishing agent. By forming an internal flow path in the column portion, the cylindrical energy storage cells can be cooled by the refrigerant flowing through the internal flow path. Furthermore, by forming a hollow portion in the column portion, when an impact sufficient to deform the cylindrical energy storage cells is applied to the energy storage module, a fire extinguishing agent can be discharged from the hollow portion of the ruptured column portion.

[0009] The energy storage module according to the above aspect preferably further includes a cooler housed in the case for cooling the cylindrical energy storage cells. The cooler is configured to come into contact with one end of the column portion in the axial direction to cool the column portion from the one end. With this configuration, the cylindrical energy storage cells can be cooled by the cooler via the column portion.

[0010] The electric storage module according to the above aspect preferably further includes a heat-conducting member disposed between one end of the column portion in the axial direction and the case. The heat-conducting member has a higher thermal conductivity than each of the column portion and the case. With this configuration, the heat-conducting member can efficiently exchange heat between the column portion and the case. As a result, the column portion can be quickly cooled.

[0011] In the energy storage module according to the above aspect, the case preferably includes a wall portion provided on one end side of the column portion in the axial direction, and a plurality of fins arranged on the wall portion. The region in which the plurality of fins are formed is provided at a position overlapping with the column portion in the axial direction. With this configuration, the column portion can be easily cooled by air cooling using the plurality of fins.

[0012] According to the present disclosure, it is possible to mitigate impacts on a plurality of cylindrical energy storage cells included in an energy storage module. [Brief description of the drawings]

[0013] [Figure 1] 1 is a plan view illustrating a configuration of an electricity storage module according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 11 is a cross-sectional view showing the configuration of an electricity storage module according to a second embodiment. [Figure 4] FIG. 11 is a cross-sectional view showing the configuration of an electricity storage module according to a third embodiment. [Diagram 5] FIG. 13 is a plan view showing the configuration of an electricity storage module according to a fourth embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. [Figure 7] FIG. 13 is a diagram showing the relationship between the thermal conductivity of the heat conduction member, and the thermal conductivity of the case and column portion according to the fourth embodiment. [Figure 8] FIG. 13 is a cross-sectional view showing the configuration of an electricity storage module according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference characters, and the description thereof will not be repeated.

[0015] [First embodiment] FIG. 1 is a plan view showing an overall configuration of an energy storage module 100 according to a first embodiment of the present disclosure. The energy storage module 100 includes a plurality of (eight in FIG. 1) energy storage cells 10, a plurality of (five in FIG. 1) column sections 20, a case 30, and a thermally conductive material 40. The numbers of the energy storage cells 10 and the column sections 20 are not limited to the above example. The energy storage module 100 is mounted on, for example, an electric vehicle. Note that the use of the energy storage module 100 is not limited to vehicle use. Note that FIG. 1 is a plan view of the energy storage module 100 with an upper lid 31, which will be described later, removed. The energy storage cell 10 is an example of a "cylindrical energy storage cell" of the present disclosure.

[0016] Each of the multiple storage cells 10 has a cylindrical shape. The multiple storage cells 10 are arranged in a lattice pattern. The multiple storage cells 10 are arranged such that their axial directions are substantially parallel to one another (for example, the angular deviation between the axial directions is within 1 degree). The axial direction is the Z direction shown in FIG. 1. The Z direction is, for example, a vertical direction, and the Z1 direction and the Z2 direction are upward and downward, respectively. The Z direction may be a direction other than the vertical direction (for example, a horizontal direction).

[0017] Each of the multiple pillar portions 20 is arranged so as to be surrounded by the multiple energy storage cells 10. Specifically, each of the multiple pillar portions 20 is provided in a gap S formed between three energy storage cells 10 arranged adjacent to one another. Each of the multiple pillar portions 20 has a cylindrical shape. Each of the multiple pillar portions 20 extends along the Z direction. That is, the axial direction of each of the multiple pillar portions 20 extends along the Z direction. Each of the multiple pillar portions 20 is formed of, for example, iron, aluminum, or the like.

[0018] When viewed along the Z direction, each of the multiple storage cells 10 has a diameter d1 (e.g., 46 mm). When viewed along the Z direction, each of the multiple column portions 20 has a diameter d2. The diameter d1 is larger than the diameter d2. For example, the diameter d1 may be four times or more the diameter d2.

[0019] The case 30 houses each of the multiple energy storage cells 10. The case 30 houses each of the multiple column portions 20. The case 30 is formed of, for example, iron or aluminum. Each of the multiple column portions 20 may be formed integrally with the case 30.

[0020] The case 30 is filled with a thermally conductive material 40 (for example, a thermally conductive resin mixed with a thermally conductive filler). The thermal conductivity of the thermally conductive material 40 is higher than the thermal conductivity of each of the case 30 and the column portions 20. The interior space of the case 30 except for the space occupied by the power storage cells 10 and the column portions 20 is filled with the thermally conductive material 40. This makes it possible to improve the efficiency of heat conduction between the power storage cells 10 and the column portions 20 (and the case 30) (ensuring a substantial contact area).

[0021] 2, the case 30 includes an upper cover 31, a bottom surface 32, and a side surface 33 (see FIG. 1) that connects the upper cover 31 and the bottom surface 32. The upper cover 31 of the case 30 may be attached to the Z2 side of the underbody 60 of the vehicle.

[0022] Here, in a conventional energy storage module, there is a problem in that an impact applied to the case is directly transmitted to the battery module. Therefore, the energy storage module of the present disclosure has the following configuration in order to reduce the impact to the energy storage cells.

[0023] Specifically, in the first embodiment, the length L1 of each of the multiple column portions 20 in the Z direction is greater than the length L2 of each of the multiple energy storage cells 10 in the Z direction.

[0024] An end 21 on the Z1 side of each of the multiple pillars 20 contacts the top cover 31. An end 22 on the Z2 side of each of the multiple pillars 20 contacts the bottom surface 32. Thus, each of the multiple pillars 20 serves as a support for the case 30. The end 22 is an example of "one end" in the present disclosure.

[0025] Furthermore, compared to a case in which the pillars 20 are not provided, the distance between the support points that support the case 30 (in this embodiment, the contact points between the pillars 20 and the case 30) can be easily reduced. As a result, problems are unlikely to occur even if the rigidity (mechanical strength) of the case 30 itself is made relatively low. This allows the case 30 to be made lighter.

[0026] An end portion 11 on the Z1 side of each of the multiple storage cells 10 is spaced from the upper lid 31. An end portion 12 on the Z2 side of each of the multiple storage cells 10 is spaced from the bottom surface 32. A thermally conductive material 40 is filled between the storage cell 10 and each of the upper lid 31 and the bottom surface 32. The storage cell 10 may be placed (fixed) on the bottom surface 32, for example.

[0027] As described above, in the first embodiment, the length L1 of the pillar portion 20 in the Z direction is greater than the length L2 of the energy storage cell 10 in the Z direction. This allows the pillar portion 20 to support the case 30 (upper lid 31, bottom surface 32), thereby mitigating impact on the energy storage cell 10. For example, the pillar portion 20 prevents an impact from being transmitted to the energy storage cell 10 when a vehicle equipped with the energy storage module 100 is traveling on a rough road. In other words, the dimensional difference between the length L1 of the pillar portion 20 and the length L2 of the energy storage cell 10 can be used as a stroke when the energy storage cell 10 interferes with the road surface.

[0028] [Second embodiment] A second embodiment of the present disclosure will be described with reference to Fig. 3. In the second embodiment, an internal flow path 121 is formed in a pillar portion 120. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will not be repeated.

[0029] The energy storage module 200 according to the second embodiment includes a plurality of pillars 120 instead of the plurality of pillars 20 of the first embodiment.

[0030] Each of the multiple pillars 120 includes an internal flow path 121 extending in the Z direction. That is, each of the multiple pillars 120 has a cylindrical shape. A refrigerant (cooling liquid) flows through the internal flow path 121. In FIG. 3, the flow of the refrigerant is indicated by dashed arrows.

[0031] Moreover, the power storage module 200 includes an upper flow path 122 and a lower flow path 123. The upper flow path 122 is provided so as to extend, for example, in the X direction along the upper lid 31. The lower flow path 123 is provided so as to extend, for example, in the X direction along the bottom surface 32. Note that the directions in which the upper flow path 122 and the lower flow path 123 extend are not limited to the above example. Although not shown in the drawings, each of the upper flow path 122 and the lower flow path 123 may be introduced from the outside to the inside of the case 30 (led from the inside to the outside) through, for example, a side surface 33 (see FIG. 1) of the case 30.

[0032] In order to introduce the upper flow path 122 and the lower flow path 123 into the case 30, the power storage module 200 may be disposed inside the vehicle body.

[0033] 3 shows an example in which the energy storage cell 10 is separated from each of the upper flow path 122 and the lower flow path 123, but the present disclosure is not limited to this. The energy storage cell 10 may be in contact with one of the upper flow path 122 and the lower flow path 123.

[0034] The internal flow path 121 is in electrical communication with each of the upper flow path 122 and the lower flow path 123. As a result, in the example shown in Fig. 3, the refrigerant flows through the lower flow path 123, the internal flow path 121, and the upper flow path 122 in that order. Note that the flow direction of the refrigerant may be reversed.

[0035] Other configurations and effects are similar to those of the first embodiment, and therefore will not be described repeatedly.

[0036] [Third embodiment] A third embodiment of the present disclosure will be described with reference to Fig. 4. In the third embodiment, a cooler 50 is provided in a power storage module 300. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will not be repeated.

[0037] The energy storage module 300 according to the third embodiment includes a cooler 50 for cooling the multiple energy storage cells 10. The cooler 50 is housed in the case 30. The cooler 50 is disposed, for example, along the bottom surface 32. Note that the cooler 50 may include cooling fins (not shown) therein and may be configured to allow air to circulate therein.

[0038] The cooler 50 is in contact with the end 22 on the Z2 side of each of the multiple column parts 20. As a result, the cooler 50 cools each of the multiple column parts 20 from the end 22. The cooler 50 may be in contact with the end 21 on the Z1 side of each of the multiple column parts 20. A cooler in contact with the end 21 and a cooler in contact with the end 22 may be provided separately.

[0039] The end 21 on the Z1 side of each of the plurality of pillar portions 20 is in contact with the underbody 60. That is, the underbody 60 serves as an upper cover of the case.

[0040] Other configurations and effects are similar to those of the first embodiment, and therefore will not be described repeatedly.

[0041] [Fourth embodiment] A fourth embodiment of the present disclosure will be described with reference to Fig. 5 to Fig. 7. In the fourth embodiment, a plurality of fins 131 are provided on a case 130 of a power storage module 400. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will not be repeated.

[0042] As shown in FIG. 5, an electricity storage module 400 according to the fourth embodiment includes a case 130 instead of the case 30 of the first embodiment.

[0043] The case 130 includes an upper cover 31, a plurality of fins 131, and a bottom surface 132 (see FIG. 6 for both). The bottom surface 132 is provided on the end portion 22 side of each of the plurality of column portions 20. The bottom surface 132 is an example of a "wall portion" in the present disclosure.

[0044] 5, region R where multiple fins 131 are formed is indicated by a dashed line. Region R is provided at a position overlapping with each of the multiple (all) column portions 20 in the Z direction. Region R is formed such that the outer periphery of region R is aligned with the outer periphery of case 130. Note that FIG. 5 is a plan view of power storage module 400 with upper lid 31 removed.

[0045] 6, each of the multiple fins 131 is provided to protrude from the bottom surface 132 toward the Z2 side. Each of the multiple fins 131 may be formed integrally with the bottom surface 132. The X direction in which the multiple fins 131 are lined up is a direction perpendicular to the traveling direction of the vehicle (the left-right direction of the vehicle).

[0046] This allows for an air-cooling structure that utilizes outside air using a plurality of fins 131, thereby improving power efficiency during low load periods. Also, the power storage module 400 can be used as a natural heat dissipation module in bicycles and the like.

[0047] A heat conductive member 70 is provided between the end portion 21 of each of the plurality of column portions 20 and the upper lid 31. The heat conductive member 70 is sandwiched between the end portion 21 and the upper lid 31. In addition, a heat conductive member 70 is provided between the end portion 22 of each of the plurality of column portions 20 and the bottom surface 132. The heat conductive member 70 is sandwiched between the end portion 22 and the bottom surface 132. As a result, each of the plurality of column portions 20 and the case 130 (upper lid 31, bottom surface 132) are thermally connected via the heat conductive member 70.

[0048] 7, the thermal conductivity of the heat conducting member 70 is higher than the thermal conductivity of each of the column portion 20 and the case 130. The heat conducting member 70 is, for example, a heat conducting resin sheet containing a heat conducting filler. The heat conducting member 70 may be in a gel (paste) form instead of a sheet form. The heat conducting member 70 may have elasticity and insulating properties.

[0049] Other configurations and effects are similar to those of the first embodiment, and therefore will not be described repeatedly.

[0050] [Fifth embodiment] A fifth embodiment of the present disclosure will be described with reference to Fig. 8. In the fifth embodiment, a column portion 220 is filled with a fire extinguishing agent. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will not be repeated.

[0051] The energy storage module 500 according to the fifth embodiment includes a plurality of pillars 220 instead of the plurality of pillars 20 of the first embodiment.

[0052] Each of the plurality of pillar portions 220 includes a hollow portion 221. The hollow portion 221 is formed so as to extend in the Z direction. That is, each of the plurality of pillar portions 220 has a cylindrical shape. The hollow portion 221 of each of the plurality of pillar portions 220 is filled with a fire extinguishing agent 80. As the fire extinguishing agent 80, for example, a gas-based fire extinguishing agent such as halon may be used. Note that, as the fire extinguishing agent 80, an agent other than a gas-based fire extinguishing agent (for example, a powder-based fire extinguishing agent, a water-based fire extinguishing agent, etc.) may be used.

[0053] Other configurations and effects are similar to those of the first embodiment, and therefore will not be described repeatedly.

[0054] In the third embodiment, an example has been described in which the underbody 60 serves as the upper cover of the case 30, but the present disclosure is not limited to this. The upper cover 31 may also be provided in the third embodiment. Also, in the first, fourth, and fifth embodiments, the underbody 60 may also serve as the upper cover of the case. Note that, in the second embodiment, the case may also be attached to the underbody 60, or the upper cover of the case may be the underbody 60.

[0055] In the above first to fifth embodiments, an example has been shown in which the case is filled with the thermally conductive material 40, but the present disclosure is not limited to this. The case may be filled with air instead of the thermally conductive material 40.

[0056] Although the above first to fifth embodiments have been described by way of example in which a plurality of pillars are provided, the present disclosure is not limited thereto, and only one pillar may be provided.

[0057] In the fourth embodiment, an example in which the heat conductive member 70 is provided has been described, but the present disclosure is not limited thereto. The heat conductive member 70 may not be provided, and each of the plurality of column portions 20 may be integrally formed with the bottom surface 132 and the plurality of fins 131.

[0058] In the fourth embodiment, an example in which the fins 131 are provided on the case 130 has been described, but the present disclosure is not limited to this, and the case of the fourth embodiment does not necessarily have to be provided with the fins 131. Furthermore, the fins 131 may be provided on each of the cases of the first, second, third, and fifth embodiments.

[0059] The configurations of the above-described embodiment and the above-described modified examples may be combined with each other.

[0060] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0061] 10 energy storage cell (cylindrical energy storage cell), 20, 120, 220 column portion, 22 end portion (one end), 30, 130 case, 50 cooler, 70 heat conductive member, 80 extinguishing agent, 100, 200, 300, 400, 500 energy storage module, 121 internal flow path, 131 fin, 132 bottom surface (wall portion), 221 hollow portion, R region, Z direction (axial direction).

Claims

1. A plurality of cylindrical storage cells arranged so that their axial directions are substantially parallel to each other; At least one pillar portion arranged to be surrounded by the plurality of cylindrical storage cells; a case that houses the plurality of cylindrical storage cells; The column portion extends along the axial direction, a length of the pillar portion in the axial direction is greater than a length of each of the plurality of cylindrical storage cells in the axial direction.

2. The electric storage module according to claim 1 , wherein the pillar portion extends in the axial direction and has an internal flow passage through which a coolant flows, or a hollow portion filled with a fire extinguishing agent.

3. a cooler housed in the case for cooling the cylindrical storage cells; The energy storage module according to claim 1 , wherein the cooler is configured to come into contact with one end of the column portion in the axial direction, thereby cooling the column portion from the one end.

4. a heat conductive member disposed between one end of the column portion in the axial direction and the case, The energy storage module according to claim 1 , wherein the thermal conductivity of the heat conducting member is higher than the thermal conductivity of each of the column portion and the case.

5. The case is A wall portion provided on one end side of the column portion in the axial direction; a plurality of fins disposed on the wall portion; The energy storage module according to any one of claims 1 to 4, wherein the region in which the plurality of fins are formed is provided at a position overlapping with the column portion in the axial direction.

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