Energy storage module

Abstract

An energy storage module comprises a multitude of energy storage cells (cylindrical energy storage cells), a column-shaped section arranged to be surrounded by the energy storage cells, and a housing that contains the energy storage cells. The column-shaped section extends along a Z-direction. The length of the column-shaped section in the Z-direction (an axial direction) is greater than the length of each of the energy storage cells in the Z-direction.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The present invention relates to a power storage module. 2. Description of the state of the art

[0002] Japanese patent JP 4 921 629 B discloses a battery pack structure in which a plurality of cylindrical battery modules are arranged. Both axial ends of each battery module are secured by means of a battery holder. SUMMARY OF THE INVENTION

[0003] In the above-mentioned JP 4 921 629 B, both axial ends of each battery module are secured using the battery holder, so that any shock exerted on the battery holder is directly transmitted to the battery modules. It is desirable to mitigate the shock exerted on the battery modules (cylindrical power storage cells).

[0004] The present invention provides a power storage module capable of mitigating shocks applied to a cylindrical power storage cell.

[0005] One aspect of the present invention relates to a power storage module comprising a plurality of cylindrical power storage cells, at least one columnar portion, and a housing. The cylindrical power storage cells are arranged such that the axial directions of the cylindrical power storage cells are approximately parallel to each other. The columnar portion is arranged to be surrounded by the cylindrical power storage cells. The housing accommodates the cylindrical power storage cells. The columnar portion extends along the axial directions. The length of the columnar portion in the axial directions is greater than the length of each of the cylindrical power storage cells in the axial directions.

[0006] In the power storage module according to the aspect of the present invention as described above, the length of the columnar portion in the axial directions is greater than the length of each of the cylindrical power storage cells in the axial directions. Accordingly, at least one axial end portion of each cylindrical power storage cell can be separated from the case. Thereby, compared with a case in which both axial ends of each cylindrical power storage cell are fixed by the case, an impact applied to the case can be prevented from being transmitted to the cylindrical power storage cells. Accordingly, an impact applied to the cylindrical power storage cells can be mitigated.

[0007] In the power storage module according to the aspect of the present invention, an internal flow path extending in the axial directions and in which a coolant flows, or a cavity portion filled with a fire extinguishing agent, may be formed in the columnar portion. Since the internal flow path is formed in the columnar portion, the cylindrical power storage cells can be cooled by the coolant flowing through the internal flow path. Furthermore, since the cavity portion is formed in the columnar portion, the fire extinguishing agent can leak from the cavity portion of the columnar portion when the power storage module is subjected to an impact so strong that the cylindrical power storage cells are deformed.

[0008] The power storage module according to the aspect of the present invention may further include a cooler housed in the casing and configured to cool the cylindrical power storage cells. The cooler may be configured to cool the columnar portion from one end of the columnar portion in the axial directions by contacting the one end. With such a configuration, the cylindrical power storage cells can be cooled by the cooler through the columnar portion.

[0009] The power storage module according to the aspect of the present invention may further include a heat-conducting member disposed between one end of the columnar portion in the axial direction and the housing. The thermal conductivity of the heat-conducting member is higher than the thermal conductivities of the columnar portion and the housing. With such a configuration, heat exchange between the columnar portion and the housing can be efficiently performed by means of the heat-conducting member. As a result, the columnar portion can be quickly cooled.

[0010] In the power storage module according to the aspect of the present invention, the case may include a wall portion provided on a side where one end of the columnar portion is provided in the axial directions, and a plurality of ribs arranged on the wall portion.

[0011] A region where the ribs are formed is provided at a position where the region overlaps the columnar portion in the axial directions. With such a configuration, the columnar portion can be easily cooled by air cooling using the ribs.

[0012] According to the aspect of the present invention, it is possible to mitigate a shock applied to a plurality of cylindrical power storage cells provided in a power storage module. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The features and advantages as well as the technical and economic significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which like reference numerals designate like elements, in which: Fig. 1 is a plan view showing a configuration of a power storage module according to a first embodiment; Fig. 2 a cross-sectional view along a line II-II of Fig. 1; Fig. 3 is a cross-sectional view showing a configuration of a power storage module according to a second embodiment; Fig. 4 is a cross-sectional view showing a configuration of a power storage module according to a third embodiment; Fig. 5 is a plan view showing a configuration of a power storage module according to a fourth embodiment; Fig. 6 a cross-sectional view along a line VI-VI of Fig. 5; Fig. 7 is a diagram showing a relationship between the thermal conductivity of a heat-conducting member, a casing, and a columnar portion according to the fourth embodiment; and Fig. 8 is a cross-sectional view showing a configuration of a power storage module according to a fifth embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] Embodiments of the present invention will be described in detail below with reference to the drawings. It should be noted that in the drawings, like or corresponding parts are designated by the same reference numerals, and their descriptions will not be repeated. First embodiment

[0015] Fig. 1 is a plan view showing an overall configuration of a power storage module 100 according to a first embodiment of the present invention. The power storage module 100 includes a plurality of (eight in Fig. 1) Power storage cells 10, a plurality of (five in Fig. 1) columnar sections or columnar sections 20, a housing 30, and a heat-conducting material 40. The number of power storage cells 10 and the number of columnar sections 20 are not limited to the examples described above. The power storage module 100 is installed, for example, in an electrified vehicle. It should be noted that the power storage module 100 may be used for a purpose other than use in a vehicle. It should be noted that Fig. 1 is a plan view of the power storage module 100 in a state after removal of a top cover 31 (which will be described later). Furthermore, the power storage cells 10 are examples of "cylindrical power storage cells" of the present invention.

[0016] Each of the power storage cells 10 has a cylindrical shape. The power storage cells 10 are arranged in a grid-like shape. The power storage cells 10 are arranged so that their axial directions are approximately parallel to each other (for example, an angular difference between the axial directions is equal to or less than 1 degree). Note that the axial directions described above are a Z direction, which is Fig. 1. Furthermore, the Z direction, for example, is a vertical direction, and a Z1 direction and a Z2 direction are an upward direction and a downward direction, respectively. The Z direction may be a direction other than the vertical direction (for example, a horizontal direction).

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

[0018] Viewed in the Z direction, each of the energy storage cells 10 has a diameter d1 (for example, 46 mm). Viewed in the Z direction, each of the columnar sections 20 has a diameter d2. The diameter d1 is larger than the diameter d2. For example, the diameter d1 can be equal to or larger than four times the diameter d2.

[0019] The housing 30 accommodates each of the power storage cells 10. The housing 30 accommodates each of the columnar sections 20. The housing 30 is made of iron or aluminum, for example. Note that each of the columnar sections 20 may be formed integrally with the housing 30.

[0020] The casing 30 is filled with the 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 conductivities of the casing 30 and each of the columnar portions 20. An interior of the casing 30 is filled with the thermally conductive material 40, except for a space occupied by the power storage cells 10 and the columnar portions 20. Accordingly, it is possible to improve the efficiency of heat conduction between the power storage cells 10 and the columnar portions 20 (and the casing 30) (it is possible to ensure the area of ​​substantial contact).

[0021] As in Fig. 2, the housing 30 comprises the upper cover 31, a bottom surface 32 and side surfaces 33 (see Fig. 1) that connect the upper cover 31 and the bottom surface 32. The upper cover 31 of the housing 30 can be attached to a Z2 side of an underbody 60 of a vehicle.

[0022] In the case of a prior art power storage module, there is a problem that a shock applied to a housing is directly transmitted to a battery module. Therefore, the power storage module of the present invention has a configuration as follows to mitigate the shock applied to the power storage cells.

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

[0024] An end portion 21 of each of the columnar portions 20 located on a Z1 side is in contact with the upper lid 31. An end portion 22 of each of the columnar portions 20 located on the Z2 side is in contact with the bottom surface 32. Therefore, each of the columnar portions 20 has a role as a pillar of the housing 30. Note that the end portion 22 is an example of the “one end” of the present invention.

[0025] Furthermore, it is easy to reduce the distances between the support points (in the present embodiment, the contact points between the columnar portions 20 and the housing 30) at which the housing 30 is supported, compared to a housing in which the columnar portions 20 are not provided. Consequently, problems are less likely to occur even if the rigidity (mechanical strength) of the housing 30 itself is relatively low. Accordingly, the weight of the housing 30 can be reduced.

[0026] An end portion 11 of each of the power storage cells 10, located on the Z1 side, is separated from the upper cover 31. An end portion 12 of each of the power storage cells 10, located on the Z2 side, is separated from the bottom surface 32. Gaps between the power storage cells 10, the upper cover 31, and the bottom surface 32 are filled with the thermally conductive material 40. Note that the power storage cells 10 can be mounted (attached), for example, to the bottom surface 32.

[0027] As described above, in the first embodiment, the length L1 of the columnar portions 20 in the Z direction is greater than the length L2 of the power storage cells 10 in the Z direction. As a result, the case 30 (the upper cover 31 and the bottom surface 32) is supported by the columnar portions 20, thereby mitigating impacts applied to the power storage cells 10. For example, the columnar portions 20 suppress the transmission of impacts to the power storage cells 10, which impacts are generated when the vehicle in which the power storage module 100 is installed travels on a rough road. In other words, a dimensional difference between the length L1 of the columnar portions 20 and the length L2 of the power storage cells 10 can be used as a stroke at the time of a road surface disturbance. Second embodiment

[0028] A second embodiment of the present invention will be described with reference to Fig. 3. In the second embodiment, internal flow paths 121 are formed in columnar sections 120. The same components as those of the first embodiment are denoted by the same reference numerals as in the first embodiment, and their description will not be repeated.

[0029] A power storage module 200 of the second embodiment includes a plurality of columnar portions 120 instead of the columnar portions 20 of the first embodiment.

[0030] Each of the columnar sections 120 includes the internal flow path 121 extending in the Z direction. That is, each of the columnar sections 120 has a cylindrical shape. A coolant (a liquid coolant) flows in the internal flow paths 121. Fig. 3 the flow of the coolant is represented by dashed arrows.

[0031] In addition, the power storage module 200 includes an upper flow path 122 and a lower flow path 123. The upper flow path 122 is provided to extend along the upper cover 31, for example, in an X direction. The lower flow path 123 is provided to extend along the bottom surface 32, for example, in the X direction. Note that the direction in which the upper flow path 122 and the lower flow path 123 each extend is not limited to the example described above. In addition, although not shown, each of the upper flow paths 122 and the lower flow paths 123 may be introduced from the outside of the housing 30 into the inside of the housing 30 (or removed from the inside of the housing 30 to the outside of the housing 30), for example, through the side surfaces 33 of the housing 30 (see Fig. 1).

[0032] It should be noted that the power storage module 200 may be arranged in a vehicle body to introduce both the upper flow path 122 and the lower flow path 123 into the housing 30.

[0033] In Fig. 3 shows an example in which the power storage cells 10 and each of the upper flow paths 122 and the lower flow paths 123 are separated from each other. However, the present invention is not limited to this. The power storage cells 10 may be in contact with any of the upper flow paths 122 and the lower flow paths 123.

[0034] The internal flow paths 121 are connected to each of the upper flow paths 122 and the lower flow paths 123. Accordingly, the fluid flows in the Fig. 3, the coolant flows through the lower flow path 123, the internal flow paths 121, and the upper flow path 122 in that order. Note that the direction in which the coolant flows can be reversed.

[0035] Since the other components and effects are the same as in the first embodiment, their description will not be repeated. Third embodiment

[0036] A third embodiment of the present invention 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 in the first embodiment are denoted by the same reference numerals as in the first embodiment, and their description will not be repeated.

[0037] The power storage module 300 of the third embodiment includes the cooler 50 for cooling the power storage cells 10. The cooler 50 is housed in the housing 30. The cooler 50 is arranged, for example, along the bottom surface 32. Note that the cooler 50 may include, for example, a cooling fin (not shown) and be configured to allow air to flow therein.

[0038] The cooler 50 contacts the end portion 22 of each of the columnar sections 20 located on the Z2 side. Accordingly, the cooler 50 cools each of the columnar sections 20 from the end portion 22. Note that the cooler 50 may contact the end portion 21 of each of the columnar sections 20 located on the Z1 side. A cooler in contact with the end portion 21 and a cooler in contact with the end portion 22 may be provided separately.

[0039] The end portion 21 of each of the columnar portions 20 located on the Z1 side is in contact with the underbody 60. That is, the underbody 60 functions as an upper housing cover.

[0040] Since the other components and effects are the same as in the first embodiment, their description will not be repeated. Fourth embodiment

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

[0042] As in Fig. 5, the power storage module 400 of the fourth embodiment includes the case 130 instead of the case 30 of the first embodiment.

[0043] The housing 130 comprises the upper cover 31, the ribs 131 and a bottom surface 132 (see Fig. 6). The bottom surface 132 is provided on a side where the end portion 22 of each of the columnar sections 20 is provided. The bottom surface 132 is an example of a "wall section" of the present invention.

[0044] In Fig. In Figure 5, a region R in which the ribs 131 are formed is shown by dashed lines. The region R is provided at a position where the region R overlaps with each of the columnar portions 20 in the Z direction. The region R is formed such that an outer peripheral edge of the region R extends along an outer peripheral edge of the housing 130. Fig. 5 is a plan view of the power storage module 400 in a state after removing the top cover 31.

[0045] As in Fig. As shown in Figure 6, each of the ribs 131 is provided to protrude from the bottom surface 132 toward the Z2 side. Each of the ribs 131 may be formed integrally with the bottom surface 132. Furthermore, the X direction in which the ribs 131 are arranged is a direction orthogonal to a direction in which the vehicle moves (a right-left direction of the vehicle).

[0046] Accordingly, it is possible to realize an air-cooling structure that utilizes outside air via the fins 131, thus improving the electric range at light loads. Furthermore, the power storage module 400 can be used as a natural heat dissipation module in a bicycle or the like.

[0047] A heat-conducting member 70 is provided between the end portion 21 and the upper cover 31 for each of the columnar sections 20. The heat-conducting member 70 is arranged between the end portion 21 and the upper cover 31. In addition, the heat-conducting member 70 is provided between the end portion 22 and the bottom surface 132 for each of the columnar sections 20. The heat-conducting member 70 is arranged between the end portion 22 and the bottom surface 132. Accordingly, each of the columnar sections 20 and the housing 130 (the upper cover 31 and the bottom surface 132) are thermally connected to each other by the heat-conducting member 70.

[0048] As in Fig. As shown in Figure 7, the thermal conductivity of the thermally conductive member 70 is higher than the thermal conductivities of each columnar portion 20 and the housing 130. The thermally conductive member 70 is, for example, a thermally conductive resin film into which a thermally conductive filler is mixed. In addition, the thermally conductive member 70 may have a gel-like form (a paste-like form) instead of a sheet-like form. In addition, the thermally conductive member 70 may have elasticity and insulation properties.

[0049] Since the other components and effects are the same as in the first embodiment, their description will not be repeated. Fifth embodiment

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

[0051] A power storage module 500 of the fifth embodiment includes a plurality of columnar portions 220 instead of the columnar portions 20 of the first embodiment.

[0052] Each of the columnar sections 220 includes a hollow section 221. The hollow section 221 is shaped to extend in the Z direction. That is, each of the columnar sections 220 has a cylindrical shape. The hollow section 221 of each of the columnar sections 220 is filled with a fire extinguishing agent 80. For example, a gaseous fire extinguishing agent such as halon can also be used as the fire extinguishing agent 80. Note that a fire extinguishing agent other than a gaseous fire extinguishing agent (for example, a powder fire extinguishing agent and a water-based fire extinguishing agent) can also be used as the fire extinguishing agent 80.

[0053] Since the other components and effects are the same as in the first embodiment, their description will not be repeated.

[0054] In the third embodiment described above, an example was described in which the lower case 60 functions as an upper cover of the housing 30. However, the present invention is not limited to this. The upper cover 31 may also be provided in the third embodiment. Furthermore, the lower case 60 may also play a role as the upper cover of the housing in the first, fourth, and fifth embodiments. Note that the housing may also be attached to the lower case 60 in the second embodiment, or the upper cover of the housing may be the lower case 60.

[0055] In the first to fifth embodiments described above, an example was described in which the housing is filled with the heat-conducting material 40. However, the present invention is not limited to this. The housing may be filled with air without being filled with the heat-conducting material 40.

[0056] In the first to fifth embodiments described above, an example in which a plurality of columnar sections are provided was described. However, the present invention is not limited to this. The number of columnar sections provided may be one.

[0057] In the fourth embodiment described above, an example in which the heat-conducting member 70 is provided was described. However, the present invention is not limited to this. The heat-conducting member 70 need not be provided, and each of the columnar portions 20 may be formed integrally with the bottom surface 132 and the ribs 131.

[0058] In the fourth embodiment described above, an example was described in which the housing 130 is provided with the ribs 131. However, the present invention is not limited to this. The housing of the fourth embodiment need not be provided with the ribs 131. Furthermore, the housing in any of the first, second, third, and fifth embodiments may be provided with the ribs 131.

[0059] The configurations in the above-described embodiments and the above-described modification examples can be combined with each other.

[0060] The embodiments disclosed herein should be considered in all respects as exemplary and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than by the description of the above-described embodiments, and is intended to include all changes within the spirit and scope of the claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 4 921 629 B [0002, 0003]

Claims

[1] Power storage module, comprising: a plurality of cylindrical power storage cells arranged such that axial directions of the cylindrical power storage cells are approximately parallel to each other; at least one columnar portion arranged to be surrounded by the cylindrical power storage cells; and a housing that houses the cylindrical power storage cells, wherein: the columnar portion extends along the axial directions; and a length of the columnar portion in the axial directions is greater than a length of each of the cylindrical power storage cells in the axial directions. [2] The power storage module according to claim 1, wherein an internal flow path extending in the axial directions and in which a coolant flows or a cavity portion filled with a fire extinguishing agent is formed in the columnar portion. [3] The power storage module according to claim 1, further comprising a cooler housed in the casing and configured to cool the cylindrical power storage cells, the cooler being configured to cool the columnar portion from one end of the columnar portion in the axial directions by being in contact with the one end. [4] The power storage module according to claim 1, further comprising a heat-conducting member disposed between one end of the columnar portion in the axial directions and the case, wherein the heat-conducting member has a heat conductivity higher than the heat conductivities of the columnar portion and the case. [5] Power storage module according to one of claims 1 to 4, wherein the housing comprises: a wall portion provided on a side where one end of the columnar portion is provided in the axial directions, and a plurality of ribs arranged on the wall portion, and a region in which the ribs are formed, which is provided at a position where the region overlaps the columnar portion in the axial directions.

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