Energy storage module

Abstract

This invention provides an energy storage module that can mitigate the impact on cylindrical energy storage cells. [Solution] The energy storage module 100 comprises a plurality of energy storage cells 10 (cylindrical energy storage cells), a column portion 20 arranged to surround the plurality of energy storage cells 10, and a case 30 that houses the plurality of energy storage cells 10. The column portion 20 extends along the Z direction. The length L1 of the column portion in the Z direction (axial direction) is greater than the length L2 of each of the plurality of energy storage cells 10 in the Z direction.

Description

Technical Field

[0001] The present disclosure relates to a power storage module.

Background Art

[0002] Japanese Patent No. 4921629 (Patent Document 1) discloses a battery pack structure in which a plurality of cylindrical battery modules are arranged. Each of the plurality of battery modules has both axial ends fixed by a battery holder.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1 above, since both axial ends of each of the plurality of battery modules are fixed by a battery holder, an impact applied to the battery holder is directly transmitted to the battery module. It is desired to mitigate the impact on the battery module (cylindrical power storage cell).

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a power storage module capable of mitigating an impact on a cylindrical power storage cell.

Means for Solving the Problems

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

[0007] In an energy storage module according to one aspect of this disclosure, as described above, the length of the column in the axial direction is greater than the length of each of the multiple cylindrical energy storage cells in the axial direction. This allows at least one of the axial ends of the cylindrical energy storage cells to be separated from the case. As a result, compared to the case where both axial ends of the cylindrical energy storage cells are fixed by the case, the transmission of shocks applied to the case to the cylindrical energy storage cells can be suppressed. This reduces the impact on the cylindrical energy storage cells.

[0008] In the energy storage module relating to the first aspect described above, preferably, the column portion extends in the axial direction and has an internal flow path through which a refrigerant flows, or a cavity filled with a fire extinguishing agent. The formation of an internal flow path in the column portion allows the cylindrical energy storage cell to be cooled by the refrigerant flowing through the internal flow path. Furthermore, the formation of a cavity in the column portion allows the fire extinguishing agent to be discharged from the cavity of the ruptured column portion if the energy storage module is subjected to an impact strong enough to deform the cylindrical energy storage cell.

[0009] The energy storage module relating to the first aspect described above is preferably housed in a case and further comprises a cooler for cooling a plurality of cylindrical energy storage cells. The cooler is configured to cool the column portion from one end by contacting one end of the column portion in the axial direction. With this configuration, the cylindrical energy storage cells can be cooled by the cooler via the column portion.

[0010] The energy storage module relating to the first aspect described above preferably further comprises a heat conductive member positioned between one end of the column in the axial direction and the case. The thermal conductivity of the heat conductive member is higher than the thermal conductivity of the column and the case, respectively. With this configuration, the heat conductive member can efficiently facilitate heat exchange between the column and the case. As a result, the column can be cooled rapidly.

[0011] The energy storage module relating to the first aspect described above preferably includes a case comprising a wall portion provided on one end of the column portion in the axial direction, and a plurality of fins arranged on the wall portion. The region where the plurality of fins are formed is located in a position that overlaps 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. [Effects of the Invention]

[0012] According to this disclosure, it is possible to mitigate impacts to the multiple cylindrical energy storage cells provided in the energy storage module. [Brief explanation of the drawing]

[0013] [Figure 1] This is a plan view showing the configuration of the energy storage module according to the first embodiment. [Figure 2] This is a cross-sectional view along line II-II in Figure 1. [Figure 3] This is a cross-sectional view showing the configuration of a power storage module according to the second embodiment. [Figure 4] This is a cross-sectional view showing the configuration of a power storage module according to the third embodiment. [Figure 5] This is a plan view showing the configuration of the energy storage module according to the fourth embodiment. [Figure 6] This is a cross-sectional view along the line VI-VI in Figure 5. [Figure 7] This figure shows the relationship between the thermal conductivity of the heat-conducting member, the case, and the column portion according to the fourth embodiment. [Figure 8] This is a cross-sectional view showing the configuration of a power storage module according to the fifth embodiment. [Modes for carrying out the invention]

[0014] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

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

[0016] Each of the plurality of power storage cells 10 has a cylindrical shape. The plurality of power storage cells 10 are arranged in a lattice pattern. The plurality of power storage cells 10 are arranged such that their axial directions are substantially parallel to each other (for example, the deviation angle between the axial directions is within 1 degree). The above axial direction is the Z direction shown in FIG. 1. The Z direction is, for example, the vertical direction, and the Z1 direction and the Z2 direction are the upper and lower directions, respectively. Note that the Z direction may be other than the vertical direction (for example, the horizontal direction).

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

[0018] When viewed along the Z direction, each of the plurality of power storage cells 10 has a diameter d1 (for example, 46 mm). When viewed along the Z direction, each of the plurality of 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 plurality of power storage cells 10. The case 30 houses each of the plurality of column portions 20. The case 30 is formed of, for example, iron or aluminum. Note that each of the plurality of column portions 20 may be integrally formed with the case 30.

[0020] The case 30 is filled with a heat conductive material 40 (for example, a heat conductive resin containing a heat conductive filler). The thermal conductivity of the heat conductive material 40 is higher than the thermal conductivity of each of the case 30 and the column portion 20. The space in the inner space of the case 30 other than the space occupied by the power storage cell 10 and the column portion 20 is filled with the heat conductive material 40. Thereby, the efficiency of heat conduction (ensuring a substantial contact area) between the power storage cell 10 and the column portion 20 (and the case 30) can be improved.

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

[0022] Here, in the conventional power storage module, there was a problem that the impact applied to the case was directly transmitted to the battery module. Therefore, the power storage module of the present disclosure has the following configuration to mitigate the impact on the power storage cell.

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

[0024] The end portion 21 on the Z1 side of each of the plurality of column portions 20 is in contact with the upper lid 31. The end portion 22 on the Z2 side of each of the plurality of column portions 20 is in contact with the bottom surface 32. Therefore, each of the plurality of column portions 20 serves as a support column of the case 30. Note that the end portion 22 is an example of the "one end" of the present disclosure.

[0025] Furthermore, compared to the case without the column portion 20, the distance between the support points supporting the case 30 (in this embodiment, the contact points between the column portion 20 and the case 30) can be easily reduced. As a result, problems are less likely to occur even if the rigidity (mechanical strength) of the case 30 itself is relatively low. This makes it possible to reduce the weight of the case 30.

[0026] Each of the multiple energy storage cells 10 has a Z1 end 11 that is spaced apart from the top cover 31. Each of the multiple energy storage cells 10 has a Z2 end 12 that is spaced apart from the bottom surface 32. A thermal conductive material 40 is filled between the energy storage cells 10 and the top cover 31 and the bottom surface 32. The energy storage cells 10 may, for example, be placed (fixed) on the bottom surface 32.

[0027] As described above, in the first embodiment, the length L1 of the column portion 20 in the Z direction is greater than the length L2 of the energy storage cell 10 in the Z direction. As a result, the case 30 (top cover 31, bottom surface 32) is supported by the column portion 20, so that the impact on the energy storage cell 10 can be mitigated. For example, when a vehicle equipped with the energy storage module 100 is traveling on a rough road, the impact transmitted to the energy storage cell 10 is suppressed by the column portion 20. In other words, the dimensional difference between the length L1 of the column portion 20 and the length L2 of the energy storage cell 10 can be used as a stroke when the road surface is in contact with the road.

[0028] [Second Embodiment] A second embodiment of the present disclosure will be described with reference to Figure 3. In the second embodiment, an internal flow path 121 is formed in the column portion 120. Components identical to those in the first embodiment will be denoted by the same reference numerals as in the first embodiment, and will not be described repeatedly.

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

[0030] Each of the multiple columnar sections 120 includes an internal flow path 121 extending in the Z direction. That is, each of the multiple columnar sections 120 has a cylindrical shape. Coolant (refrigerant) flows through the internal flow path 121. In Figure 3, the flow of the coolant is represented by dashed arrows.

[0031] The energy storage module 200 also includes an upper flow path 122 and a lower flow path 123. The upper flow path 122 is provided to extend, for example, in the X direction along the top cover 31. The lower flow path 123 is provided to extend, for example, in the X direction along the bottom surface 32. Note that the direction in which the upper flow path 122 and the lower flow path 123 extend is not limited to the above example. Although not shown in the illustration, the upper flow path 122 and the lower flow path 123 may also be introduced into the case 30 from the outside (or led out from the inside) through, for example, the side surface 33 of the case 30 (see Figure 1).

[0032] Furthermore, in order to introduce the upper flow path 122 and the lower flow path 123 into case 30, the energy storage module 200 may be located inside the vehicle body.

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

[0034] The internal flow path 121 is electrically connected to the upper flow path 122 and the lower flow path 123, respectively. As a result, in the example shown in Figure 3, the refrigerant flows in the order of lower flow path 123, internal flow path 121, and upper flow path 122. Note that the direction of refrigerant flow may be reversed.

[0035] Furthermore, the other configurations and effects are the same as those of the first embodiment described above, so no further explanation will be given.

[0036] [Third Embodiment] A third embodiment of the present disclosure will be described with reference to Figure 4. In the third embodiment, the energy storage module 300 is equipped with a cooler 50. Components identical to those in the first embodiment will be denoted by the same reference numerals as in the first embodiment, and will not be described repeatedly.

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

[0038] The cooler 50 is in contact with the Z2-side end 22 of each of the multiple column sections 20. This allows the cooler 50 to cool each of the multiple column sections 20 from the end 22. The cooler 50 may also be in contact with the Z1-side end 21 of each of the multiple column sections 20. Separate coolers may be provided for contacting the end 21 and for contacting the end 22.

[0039] Each of the Z1-side ends 21 of the multiple column sections 20 is in contact with the underbody 60. In other words, the underbody 60 acts as the top cover of the case.

[0040] Furthermore, the other configurations and effects are the same as those of the first embodiment described above, so no further explanation will be given.

[0041] [Fourth Embodiment] A fourth embodiment of this disclosure will be described with reference to Figures 5 to 7. In the fourth embodiment, a plurality of fins 131 are provided on the case 130 of the energy storage module 400. Components identical to those in the first embodiment will be denoted by the same reference numerals as in the first embodiment and will not be described repeatedly.

[0042] As shown in Figure 5, the energy 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 a top cover 31, a plurality of fins 131, and a bottom surface 132 (see Figure 6 for both). The bottom surface 132 is provided on the end 22 side of each of the plurality of column portions 20. The bottom surface 132 is an example of a "wall portion" in this disclosure.

[0044] In Figure 5, the region R where multiple fins 131 are formed is shown by a dashed line. Region R is located in a position that overlaps with each of the multiple (all) column portions 20 in the Z direction. Region R is formed so that its outer edge follows the outer edge of the case 130. Figure 5 is a plan view of the energy storage module 400 with the top cover 31 removed.

[0045] As shown in Figure 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 integrally formed with the bottom surface 132. The X direction in which the multiple fins 131 are aligned is perpendicular to the direction of travel of the vehicle (the left-right direction of the vehicle).

[0046] This allows for the creation of an air-cooling structure using multiple fins 131 and outside air, thereby improving energy efficiency at low loads. Furthermore, the energy storage module 400 can be used as a natural heat dissipation module in bicycles and other devices.

[0047] A heat conduction member 70 is provided between each end 21 of the multiple column sections 20 and the top cover 31. The heat conduction member 70 is sandwiched between the end 21 and the top cover 31. In addition, a heat conduction member 70 is provided between each end 22 of the multiple column sections 20 and the bottom surface 132. The heat conduction member 70 is sandwiched between the end 22 and the bottom surface 132. As a result, each of the multiple column sections 20 and the case 130 (top cover 31, bottom surface 132) are thermally connected via the heat conduction member 70.

[0048] As shown in Figure 7, the thermal conductivity of the heat conductive member 70 is higher than that of the column portion 20 and the case 130, respectively. The heat conductive member 70 is, for example, a heat conductive resin sheet containing a heat conductive filler. The heat conductive member 70 may also be in the form of a gel (paste) rather than a sheet. Furthermore, the heat conductive member 70 may have elasticity and insulating properties.

[0049] Furthermore, the other configurations and effects are the same as those of the first embodiment described above, so no further explanation will be given.

[0050] [Fifth Embodiment] A fifth embodiment of the present disclosure will be described with reference to Figure 8. In the fifth embodiment, the column portion 220 is filled with a fire extinguishing agent. Components identical to those in the first embodiment will be denoted by the same reference numerals as in the first embodiment, and will not be described repeatedly.

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

[0052] Each of the multiple columnar sections 220 includes a cavity 221. The cavity 221 is formed to extend in the Z direction. That is, each of the multiple columnar sections 220 has a cylindrical shape. The cavity 221 of each of the multiple columnar sections 220 is filled with a fire extinguishing agent 80. As the fire extinguishing agent 80, for example, a gaseous fire extinguishing agent such as halon may be used. However, the fire extinguishing agent 80 may also be something other than a gaseous fire extinguishing agent (for example, a powder-based fire extinguishing agent or a water-based fire extinguishing agent).

[0053] Furthermore, the other configurations and effects are the same as those of the first embodiment described above, so no further explanation will be given.

[0054] In the third embodiment described above, an example was shown in which the underbody 60 serves as the top cover of the case 30, but the disclosure is not limited thereto. In the third embodiment as well, a top cover 31 may be provided. Also, in the first, fourth, and fifth embodiments as well, the underbody 60 may serve as the top cover of the case. In the second embodiment as well, the case may be attached to the underbody 60, or the top cover of the case may be the underbody 60.

[0055] In the first to fifth embodiments described above, examples were shown in which the case is filled with a thermal conductive material 40, but the disclosure is not limited thereto. The case may be filled with air instead of the thermal conductive material 40.

[0056] The first to fifth embodiments described above show examples in which multiple column sections are provided, but the disclosure is not limited thereto. Only one column section may be provided.

[0057] In the fourth embodiment described above, an example in which a heat conductive member 70 is provided is shown, but the 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 described above, an example is shown in which the case 130 is provided with fins 131, but the disclosure is not limited thereto, and the case of the fourth embodiment may not be provided with fins 131. Also, each of the cases of the first, second, third, and fifth embodiments may be provided with fins 131.

[0059] Furthermore, the configurations of the above embodiments and each of the above modified examples may be combined with each other.

[0060] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0061] 10 Energy storage cell (cylindrical energy storage cell), 20, 120, 220 Column section, 22 End section (one end), 30, 130 Case, 50 Cooler, 70 Heat conductive member, 80 Fire extinguishing agent, 100, 200, 300, 400, 500 Energy storage module, 121 Internal flow path, 131 Fin, 132 Bottom surface (wall section), 221 Cavity section, R region, Z direction (axial direction).

Claims

1. Multiple cylindrical energy storage cells are arranged so that their axial directions are approximately parallel to each other, At least one columnar portion is arranged so as to surround the plurality of cylindrical energy storage cells, The system comprises a case for housing the plurality of cylindrical energy storage cells, The column portion extends along the axial direction, An energy storage module in which the length of the column in the axial direction is greater than the length of each of the plurality of cylindrical energy storage cells in the axial direction.

2. The energy storage module according to claim 1, wherein the column extends in the axial direction and has an internal flow path through which a refrigerant flows, or a cavity filled with a fire extinguishing agent.

3. The case is further equipped with a cooler for cooling the plurality of cylindrical energy storage cells, The energy storage module according to claim 1, wherein the cooler is configured to cool the column portion from one end by contacting the one end of the column portion in the axial direction.

4. The system further comprises a heat conductive member positioned 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 the column portion and the case, respectively.

5. The aforementioned case is, A wall portion provided on one end side of the column portion in the axial direction, The wall portion includes a plurality of fins arranged on the wall portion, The energy storage module according to any one of claims 1 to 4, wherein the region where the plurality of fins are formed is provided in a position that overlaps with the column portion in the axial direction.

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