Energy storage modules and energy storage packs

Abstract

To provide an energy storage module with improved sealing performance between the gas discharge valve and the exhaust duct. [Solution] The energy storage module disclosed herein comprises a plurality of energy storage devices 100 arranged along the arrangement direction, a housing for housing the plurality of energy storage devices 100, gas discharge valves 17 provided on each of the plurality of energy storage devices 100, an exhaust duct 400 extending along the arrangement direction so as to cover the plurality of gas discharge valves 17 of the plurality of energy storage devices 100 and positioned on the outer surface of the plurality of energy storage devices 100, and a pressing member 450 for pressing the exhaust duct 400 toward the plurality of energy storage devices 100.

Description

Technical Field

[0001] The present invention relates to a power storage module and a power storage pack.

Background Art

[0002] Conventionally, as a power source for vehicle driving or the like, a power storage module including a plurality of power storage devices arranged in a predetermined arrangement direction has been used. For example, in Japanese Patent Application Laid-Open No. H22-086773 (Patent Document 1), each of the plurality of power storage devices has a gas discharge valve, and the power storage module further has an exhaust duct that extends along the arrangement direction so as to cover the gas discharge valves of the plurality of power storage devices and is adhesively fixed to the power storage devices.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, in power storage modules, the number of power storage devices has increased and the length in the arrangement direction has become longer. In addition, due to the increase in the capacity of individual power storage devices, the pressure of the gas discharged from the gas discharge valves has increased. Therefore, it is required to improve the sealing performance between the gas discharge valves of the power storage devices and the exhaust duct.

[0005] The present invention has been made in view of the above circumstances, and its main object is to provide a power storage module and a power storage pack with improved sealing performance between a gas discharge valve and an exhaust duct.

Means for Solving the Problems

[0006] The present invention discloses an energy storage module comprising: a plurality of energy storage devices arranged along the direction of arrangement; a housing for housing the plurality of energy storage devices; gas discharge valves provided on each of the plurality of energy storage devices; exhaust ducts extending along the direction of arrangement so as to cover the plurality of gas discharge valves of the plurality of energy storage devices and positioned on the outer surfaces of the plurality of energy storage devices; and a pressing member for pressing the exhaust ducts toward the energy storage devices.

[0007] By pressing the exhaust duct towards the energy storage device with a pressing member, the exhaust duct is less likely to separate from the gas discharge valve even if a large amount of gas is ejected from the gas discharge valve. Therefore, the sealing performance between the gas discharge valve and the exhaust duct can be relatively improved compared to the case without a pressing member. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic perspective view showing a battery storage pack according to one embodiment. [Figure 2] Figure 2 is a perspective view showing the cover body from Figure 1 with the cover removed. [Figure 3] Figure 3 is a schematic perspective view showing multiple energy storage modules as shown in Figure 2. [Figure 4] Figure 4 is a schematic perspective view of a single energy storage device. [Figure 5] Figure 5 is a cross-sectional view of the first energy storage module in Figure 3, using the VV line. [Figure 6] Figure 6 is a diagram equivalent to Figure 5, showing multiple second energy storage modules as shown in Figure 3. [Modes for carrying out the invention]

[0009] Hereinafter, preferred embodiments of the technology disclosed herein will be described with reference to the drawings as appropriate. Matters other than those specifically mentioned herein that are necessary for carrying out the technology disclosed herein (for example, the general configuration and manufacturing process of energy storage modules and energy storage packs that do not characterize the technology disclosed herein) can be understood as design matters of those skilled in the art based on the prior art. The technology disclosed herein can be carried out based on the content disclosed herein and common technical knowledge in the art.

[0010] In the following drawings, the symbols F, Rr, L, R, U, and D represent front, back, left, right, up, and down, respectively, and the symbols X, Y, and Z represent the first direction, the second direction perpendicular to the first direction, and the third direction perpendicular to both the first and second directions, respectively. The first direction X is the arrangement direction of the energy storage device 100, which will be described later. However, these are merely directions for the sake of explanation and do not limit the installation configuration of the energy storage module and energy storage pack in any way. Also, in the following drawings, the same symbols are used for members and parts that perform the same function, and redundant explanations may be omitted or simplified.

[0011] Figure 1 is a schematic perspective view of a power storage pack 800 according to one embodiment. As shown in Figure 1, the power storage pack 800 comprises a plurality of power storage modules 500 and a pack case 600 that houses the plurality of power storage modules 500. The power storage pack 800 of this embodiment further comprises an exhaust pipe 700. The exhaust pipe 700 extends from the inside to the outside of the pack case 600. One end 700e of the exhaust pipe 700 extends to the outside of the pack case 600.

[0012] The pack case 600 is an outer casing that houses multiple energy storage modules 500. The material of the pack case 600 can be the same as that conventionally used, and there are no particular restrictions. The pack case 600 is preferably made of metal, and more preferably of aluminum, aluminum alloy, iron, iron alloy, stainless steel, etc. In this case, the pack case 600 has a pack case body 610 having an opening 610h and a cover body 620 that covers the opening 610h. The pack case body 610 and the cover body 620 are fastened together and integrated by a plurality of fastening parts, for example (not shown). The pack case body 610 and the cover body 620 partition the internal space 600A of the pack case 600. Multiple energy storage modules 500 are housed in the internal space 600A.

[0013] Figure 2 is a perspective view showing the state with the cover body 620 of Figure 1 removed. As shown in Figure 2, the multiple energy storage modules 500 are arranged in the internal space 600A of the pack case 600, here in the second direction Y. The number of energy storage modules 500 is multiple (specifically four). However, the number of energy storage modules 500 is not particularly limited and may be three or fewer, or one. In this embodiment, the multiple energy storage modules 500 include a first energy storage module 500A and a second energy storage module 500B.

[0014] The first energy storage module 500A is positioned at both ends of the second direction Y (the left and right ends in Figure 2). The second energy storage module 500B is positioned between the two first energy storage modules 500A in the second direction Y. The number of first energy storage modules 500A and second energy storage modules 500B is multiple (specifically two) in this embodiment. However, in other embodiments, the number of first energy storage modules 500A and / or second energy storage modules 500B may be one. Also, the number of first energy storage modules 500A and second energy storage modules 500B may differ from the number of second energy storage modules 500B.

[0015] The exhaust pipe 700 is connected to multiple exhaust ducts 400 provided in multiple energy storage modules 500, and constitutes a flow path for gas flowing out from the multiple exhaust ducts 400. In this case, the exhaust pipe 700 extends along the second direction Y, at the far end of the first direction X in Figure 2. The exhaust pipe 700 is attached to the pack case 600 (specifically the pack case body 610) by fixing members.

[0016] Figure 3 is a schematic perspective view showing multiple energy storage modules 500. Figure 3 also shows an exhaust pipe 700 to facilitate understanding of the positional relationships between components. Furthermore, in Figure 3, only the leftmost first energy storage module 500A is shown with the terminal covers 30c, 40c, exhaust duct 400, and bridging member 450 (described later) removed. The configuration of the energy storage modules 500 will be explained below using the first energy storage module 500A as an example. The second energy storage module 500B may be the same as the first energy storage module 500A, except that it has a different type of pressing member (specifically, a plate-shaped member 460 instead of the bridging member 450, described later).

[0017] As shown at the left end of Figure 3, the first energy storage module 500A of this embodiment comprises a plurality of energy storage devices 100 arranged along the array direction X, spacers 200 positioned between adjacent energy storage devices 100 in the array direction X, and a restraining mechanism 300 that restrains the plurality of energy storage devices 100 and the spacers 200 in the array direction X. Furthermore, as shown at the right end of Figure 3, the first energy storage module 500A of this embodiment further comprises terminal covers 30c, 40c, an exhaust duct 400, and a bridging member 450. However, the spacers 200 and the terminal covers 30c, 40c are not essential and may be partially or entirely omitted in other embodiments.

[0018] The restraint mechanism 300 integrally holds a plurality of power storage devices 100. The restraint mechanism 300 is configured to apply a prescribed restraint load to the plurality of power storage devices 100 in the arrangement direction X. Here, the restraint mechanism 300 is configured to apply a prescribed restraint load to the plurality of power storage devices 100 and the spacers 200 in the arrangement direction X. The restraint mechanism 300 has a housing space that houses the plurality of power storage devices 100 and the spacers 200, and a plurality of wall members that partition the housing space. The restraint mechanism 300 is an example of a "housing that houses a plurality of power storage devices".

[0019] As shown at the left end of FIG. 3, the restraint mechanism 300 here includes a pair of end plates 310, a pair of side plates 320, and a fastening portion 330. The pair of end plates 310 and the pair of side plates 320 are preferably made of metal. However, a part thereof may be made of resin. The pair of end plates 310 and / or the pair of side plates 320 are an example of a "pair of opposed wall members". Note that the configuration of the restraint mechanism 300 is not limited to this. The restraint mechanism 300 may include, for example, a restraint band or the like instead of or in addition to the side plates 320.

[0020] The pair of end plates 310 are respectively arranged at both ends of the first power storage module 500A in the arrangement direction X. The pair of end plates 310 are arranged to face each other in the arrangement direction X. The pair of end plates 310 sandwich the plurality of power storage devices 100 and the spacers 200 in the arrangement direction X. Fastening portions 330 (such as screws and bolts) are provided at the four corners of the end plates 310.

[0021] A pair of side plates 320 (also referred to as binding bars) connect a pair of end plates 310. The pair of side plates 320 are arranged opposite to each other in a second direction Y that intersects the arrangement direction X. The side plate 320 here has a main body portion 329, a first bent portion 321, and a second bent portion 322. The main body portion 329 is a flat plate portion that extends along the arrangement direction X on the sides (left and right in FIG. 3) of the plurality of power storage devices 100 and spreads in the XZ plane of FIG. 3. A plurality of openings are provided in the main body portion 329 along the arrangement direction X.

[0022] The first bent portion 321 extends from both ends in the arrangement direction X of the main body portion 329 (the front end and the rear end in FIG. 3) respectively and is a portion bent toward the end plate 310 side. The first bent portion 321 spreads in the YZ plane of FIG. 3. The first bent portion 321 is fixed to the end plate 310 by a fastening portion 330 so that the restraint load is generally about 3 to 15 kN, preferably about 5 to 10 kN. Thereby, a restraint load is applied to the plurality of power storage devices 100 and the spacers 200 from the arrangement direction X.

[0023] The second bent portion 322 extends from one end in the third direction Z of the main body portion 329 (the upper end in FIG. 3) and is a portion bent toward the power storage device 100 side. The second bent portion 322 spreads in the XY plane of FIG. 3. A stud bolt 323 is provided on the second bent portion 322. In the present embodiment, a cross-linking member 450 described later is bridged over the second bent portion 322 via the stud bolt 323 (see also the first power storage module 500A at the right end of FIG. 3).

[0024] The spacer 200 is a component used to separate the multiple energy storage devices 100. The spacer 200 is preferably an insulating material. As shown at the left end of Figure 3, the spacer 200 is positioned between the multiple energy storage devices 100 in the arrangement direction X. That is, in the first energy storage module 500A, the energy storage devices 100 and the spacer 200 are arranged alternately in the arrangement direction X. However, the energy storage devices 100 and the spacer 200 do not necessarily have to be arranged alternately in the arrangement direction X. In other embodiments, other components (such as conventionally known thermal insulation materials) may be placed between the energy storage devices 100 and the spacer 200.

[0025] The spacer 200 has, in addition to a portion (insertion portion) positioned between the multiple energy storage devices 100, a pair of flange portions 210 that protrude from the insertion portion to the first surface side (upper surface side in Figure 3) of the multiple energy storage devices 100. The pair of flange portions 210 are provided on the first surface side of the multiple energy storage devices 100 between the electrode terminals (positive electrode terminal 30 and negative electrode terminal 40, see Figures 4 and 5) and the gas discharge valve 17. The pair of flange portions 210 sandwich the gas discharge valve 17 from the second direction Y. The flange portions 210 of the multiple energy storage devices 100 are aligned linearly along the arrangement direction X. The flange portions 210 of the multiple energy storage devices 100 are aligned substantially parallel to the second bent portion 322 of the side plate 320. An exhaust duct 400, described later, is attached to the flange portion 210 (see also the first energy storage module 500A at the far right of Figure 3).

[0026] Multiple energy storage devices 100 are arranged between a pair of end plates 310, as shown at the left end of Figure 3, along the alignment direction X (the thickness direction of the energy storage devices 100). The multiple energy storage devices 100 are integrated by a restraining mechanism 300 while aligned in the alignment direction X. The multiple energy storage devices 100 have the same shape and size. In this embodiment, even-numbered energy storage devices 100 in the alignment direction X are arranged rotated 180° (inverted) relative to odd-numbered energy storage devices 100 in the alignment direction X.

[0027] The energy storage device 100 is a device that can be repeatedly charged and discharged. In this specification, "energy storage device" is a concept that encompasses secondary batteries such as lithium-ion secondary batteries and nickel-metal hydride batteries, and capacitors such as lithium-ion capacitors, pseudocapacitive capacitors, and electric double-layer capacitors. Furthermore, the shape, size, number, etc., of the multiple energy storage devices 100 constituting the first energy storage module 500A can be changed as appropriate without being limited to the configuration shown in Figure 3.

[0028] Figure 4 is a perspective view of the energy storage device 100. As shown in Figure 4, the energy storage device 100 is a flattened prismatic shape. The energy storage device 100 is a prismatic secondary battery. The energy storage device 100 of this embodiment includes a battery case 10, a gas exhaust valve 17, a positive electrode terminal 30, a negative electrode terminal 40, and an electrode body and electrolyte (not shown). The electrode body has a positive electrode and a negative electrode. The electrolyte is typically a non-aqueous electrolyte containing a non-aqueous solvent and a supporting salt (electrolyte salt). The electrode body and electrolyte can be the same as in the conventional design and are not particularly limited. Therefore, a detailed explanation is omitted. The energy storage device 100 is here a non-aqueous electrolyte secondary battery, and more specifically, a lithium-ion secondary battery.

[0029] The battery case 10 is a container for housing the electrode body and electrolyte. As shown in Figure 4, the battery case 10 has a flattened rectangular parallelepiped (square) shape. The material of the battery case 10 can be the same as that used conventionally, and there are no particular restrictions. The battery case 10 is preferably made of metal, and more preferably of aluminum, aluminum alloy, iron, iron alloy, stainless steel, etc. In this case, the battery case 10 comprises a case body 12 having an opening and a sealing plate 14 (lid) that seals the opening.

[0030] The case body 12 is in the shape of a bottomed rectangular tube. The case body 12 comprises a substantially rectangular bottom surface 12a having long sides and short sides, a pair of long sides 12b extending from a pair of long sides of the bottom surface 12a and facing each other, and a pair of short sides 12c extending from a pair of short sides of the bottom surface 12a and facing each other. The bottom surface 12a faces the opening of the case body 12. The long sides 12b are surfaces perpendicular to the arrangement direction X. The long sides 12b are surfaces that face (more specifically, abut) the spacer 200. In this specification, "substantially rectangular" is a term that includes not only a perfect rectangle, but also shapes such as those in which the corners connecting the long and short sides of a rectangle are rounded (R-shaped), or shapes with notches at the corners.

[0031] As can be seen from Figure 3, in the first energy storage module 500A, the multiple energy storage devices 100 are arranged so that their long sides 12b, which will be described later, face each other. In other words, the multiple energy storage devices 100 are arranged so that their long sides 12b are approximately parallel to each other.

[0032] As shown in Figure 4, the sealing plate 14 is substantially rectangular in plan view. The sealing plate 14 is a plate-shaped member that extends along the XY plane. The sealing plate 14 is attached to the case body 12 so as to close the opening. The sealing plate 14 faces the bottom surface 12a of the case body 12. The battery case 10 is integrated with the case body 12 by joining (preferably by welding) the sealing plate 14 to the periphery of the opening. The battery case 10 is airtightly sealed.

[0033] The sealing plate 14 is provided with an electrolyte injection hole 15, a gas discharge valve 17, a positive electrode terminal 30, and a negative electrode terminal 40. The electrolyte injection hole 15 is for injecting electrolyte into the battery case 10 after the sealing plate 14 has been assembled to the case body 12. After the electrolyte has been injected, the electrolyte injection hole 15 is sealed by a sealing member 16. In the second direction Y, the electrolyte injection hole 15 is located between the gas discharge valve 17 and the positive electrode terminal 30.

[0034] The gas discharge valve 17 is configured to rupture when gas is generated inside the battery case 10 and the internal pressure of the battery case 10 exceeds a predetermined value due to the generated gas. This allows the gas generated inside the battery case 10 to be discharged to the outside of the battery case 10. In this embodiment, the gas discharge valve 17 is provided on the sealing plate 14. The gas discharge valve 17 is provided on the same surface (first surface, top surface in Figure 4) as the positive electrode terminal 30 and / or negative electrode terminal 40. However, the position and shape of the gas discharge valve 17 can be changed as appropriate. In other embodiments, the gas discharge valve 17 may be provided on the case body 12 side (for example, the bottom surface 12a), or on a surface different from the positive electrode terminal 30 and / or negative electrode terminal 40.

[0035] In some embodiments, the gas discharge valve 17 is preferably located at a position that coincides with the center of the surface on which the gas discharge valve 17 is provided (here, the sealing plate 14). If the surface on which the gas discharge valve 17 is provided (here, the sealing plate 14) is substantially rectangular in shape, the gas discharge valve 17 is preferably located in the center of the longer side direction (the second direction Y in Figure 4). This reduces the uneven distribution of gas pressure when gas is discharged from the gas discharge valve 17.

[0036] As can be seen in Figure 3, in this embodiment, the gas discharge valves 17 of the multiple energy storage devices 100 are arranged in a straight line along the arrangement direction X. As will be described in more detail later, the multiple gas discharge valves 17 arranged in the arrangement direction X are each connected to the exhaust duct 400 (see also the first energy storage module 500A at the far right of Figure 3). Therefore, the gas discharged from the gas discharge valves 17 of the energy storage devices 100 flows into the exhaust duct 400.

[0037] As shown in Figure 4, the positive terminal 30 and the negative terminal 40 are located at both ends of the sealing plate 14 in the second direction Y. The positive terminal 30 and the negative terminal 40 are fixed to the sealing plate 14. The positive terminal 30 and the negative terminal 40 are located on the same surface as the gas exhaust valve 17 (first surface, top surface in Figure 4). In the second direction Y, the positive terminal 30 and the negative terminal 40 are positioned so as to sandwich the gas exhaust valve 17. In the second direction Y, the negative terminal 40 is located on the opposite side of the gas exhaust valve 17 from the positive terminal 30. The positive terminal 30 and the negative terminal 40 extend from the inside to the outside of the battery case 10. The positive terminal 30 is electrically connected to the positive electrode of the electrode body inside the case body 12. The negative terminal 40 is electrically connected to the negative electrode of the electrode body inside the case body 12. The positive terminal 30 and the negative terminal 40 are examples of "electrode terminals".

[0038] The positive terminal 30 and the negative terminal 40 are equipped with busbars that electrically connect multiple energy storage devices 100 to each other. In this embodiment, of two adjacent energy storage devices 100 in the array direction X, the positive terminal 30 of one energy storage device 100 and the negative terminal 40 of the other energy storage device 100 are electrically connected by a busbar. As a result, multiple energy storage devices 100 are electrically connected in series. However, the method of connecting multiple energy storage devices 100 is not limited to series; for example, they may be connected in parallel, multiple series, multiple parallel, etc.

[0039] As can be seen from Figure 3, in this embodiment, the multiple positive terminals 30 and multiple negative terminals 40 of the multiple energy storage devices 100 are arranged linearly along the arrangement direction X. The electrode terminals (positive terminals 30 and negative terminals 40) and busbars are covered on the side away from the battery case 10 by terminal covers 30c and 40c. The terminal covers 30c and 40c extend along the arrangement direction X. The terminal covers 30c and 40c are preferably made of insulating material. The terminal covers 30c and 40c are made of resin, for example. The terminal covers 30c and 40c are attached here to the restraining mechanism 300 (housing). Specifically, one end of the terminal covers 30c and 40c in the second direction Y is attached to the second bent portion 322 of the side plate 320. However, in other embodiments, the terminal covers 30c and 40c may be attached, for example, to the flange portion 210 of the spacer 200, or to a pair of end plates 310.

[0040] The exhaust duct 400 is a component that constitutes the exhaust path for the gas discharged from the gas discharge valve 17 of the energy storage device 100 when the internal pressure of the battery case 10 exceeds a predetermined value. The exhaust duct 400 is configured to guide the gas discharged from the gas discharge valve 17 of the energy storage device 100 to the outside of the first energy storage module 500A. The exhaust duct 400 is preferably made of a heat-resistant material such as metal or ceramic.

[0041] The exhaust duct 400 is arranged on the outer surface of the multiple energy storage devices 100. In this embodiment, as shown in Figure 3, a gas discharge valve 17 is provided on the sealing plate 14 (upper surface in Figure 3), and the exhaust duct 400 is arranged above the energy storage devices 100. However, in other embodiments, if the gas discharge valve 17 is provided on the case body 12 side, the exhaust duct 400 may be arranged to the side of the energy storage devices 100 (left or right in Figure 3) or below.

[0042] The exhaust duct 400 extends along the arrangement direction X so as to cover the multiple gas exhaust valves 17 of the multiple energy storage devices 100. In some embodiments, the exhaust duct 400 is preferably provided along the terminal covers 30c, 40c, as shown at the right end of Figure 3. More preferably, the exhaust duct 400 is provided between the two terminal covers 30c, 40c in a second direction Y. In some embodiments, the exhaust duct 400 is preferably provided in a position that does not overlap with the electrode terminals (positive terminal 30 and negative terminal 40) of the energy storage devices 100 in a plan view. This makes it less likely for the exhaust duct 400 to interfere with the busbar and facilitates the electrical connection of the multiple energy storage devices 100 to each other.

[0043] The exhaust duct 400 of this embodiment has a hollow section 400A through which gas flows, extending along the arrangement direction X, a cylindrical wall plate 410 that partitions the hollow section 400A, a gas discharge hole HL provided at one end of the wall plate 410 in the arrangement direction X (the far end in Figure 3) and connected to the exhaust pipe 700, and a plurality of extensions 420 that extend outward (to the opposite side from the hollow section 400A) from both edges of the wall plate 410 in the second direction Y.

[0044] The hollow section 400A is not in communication with the inside of the energy storage device 100 when the internal pressure of the energy storage device 100 is below a predetermined value. On the other hand, the hollow section 400A is in communication with the inside of the energy storage device 100 when the internal pressure of the energy storage device 100 exceeds a predetermined value and the gas discharge valve 17 ruptures. As a result, the gas discharged from the gas discharge valve 17 flows into the hollow section 400A of the exhaust duct 400. The gas that flows into the hollow section 400A flows out from the gas discharge hole HL into the exhaust pipe 700. Then, it is discharged to the outside of the energy storage pack 800 from one end 700e of the exhaust pipe 700.

[0045] In this embodiment, the exhaust duct 400 is placed over the upper surface (sealing plate 14) of the energy storage devices 100 so as to cover the gas discharge valves 17 of the energy storage devices 100 after the energy storage devices 100 have been restrained and integrated by the restraining mechanism 300. The extension portion 420 is then mechanically fixed by being attached to the flange portion 210 of the spacer 200 by fastening portions or the like (see also Figure 5). In this embodiment, the exhaust duct 400 is attached to the spacer 200, but in other embodiments, the exhaust duct 400 may be attached to a member other than the spacer 200. The exhaust duct 400 may be attached, for example, to terminal covers 30c, 40c or to the restraining mechanism 300 (a pair of end plates 310, etc.). The exhaust duct 400 may also be adhesively fixed to the surface (first surface, upper surface in Figure 3) on which the gas discharge valves 17 of the energy storage devices 100 are provided.

[0046] Figure 5 is a cross-sectional view of the first energy storage module 500A in Figure 3 along the VV line. As shown in Figure 5, the wall plate 410 that partitions the hollow portion 400A of the exhaust duct 400 is rectangular in shape and has a bottom wall portion 410a facing the upper surface (sealing plate 14) of the energy storage device 100, an upper wall portion 410b facing the bottom wall portion 410a, and a side wall portion 410c connecting the bottom wall portion 410a and the upper wall portion 410b.

[0047] The bottom wall portion 410a is provided to cover the gas discharge valves 17 of the multiple energy storage devices 100 and their peripheral edges. In the second direction Y, the bottom wall portion 410a is longer than the gas discharge valves 17. The bottom wall portion 410a is provided with gas inlets 410h at positions opposite to the gas discharge valves 17 of the multiple energy storage devices 100. The gas inlets 410h are through holes.

[0048] The upper wall portion 410b is the surface away from the energy storage device 100. The bridging member 450, which will be described later, is in contact with the upper wall portion 410b. The upper wall portion 410b is pressed down from above by the bridging member 450. As a result, the exhaust duct 400 is pressed against the side of the energy storage device 100, specifically the surface (first surface) on which the gas discharge valve 17 is located. One end of the side wall portion 410c (the lower end in Figure 5) extends further toward the energy storage device 100 (towards the sealing plate 14) than the bottom wall portion 410a. A sealing member 430 is fitted between the portion of the side wall portion 410c that extends from the bottom wall portion 410a, that is, between the bottom wall portion 410a and the energy storage device 100.

[0049] The sealing member 430 is positioned between the first surface (sealing plate 14) of the energy storage device 100 and the bottom wall portion 410a of the exhaust duct 400. By interposing the sealing member 430, the sealing performance between the energy storage device 100 and the exhaust duct 400 can be improved. However, the sealing member 430 is not essential and can be omitted in other embodiments. The sealing member 430 is made of an elastic material such as resin or rubber. The sealing member 430 is, for example, a porous sponge. The sealing member 430 has through holes at positions facing the gas discharge valve 17 of the energy storage device 100 and the gas inlet 410h of the bottom wall portion 410a. The sealing member 430 is pressed towards the first surface (sealing plate 14) of the energy storage device 100 when the extension portion 420 is attached to the flange portion 210 of the spacer 200. As a result, the sealing member 430 is compressed in the thickness direction (third direction Z) between the first surface of the energy storage device 100 and the bottom wall portion 410a of the exhaust duct 400. The space between the first surface of the energy storage device 100 (specifically, the peripheral edge of the gas discharge valve 17) and the exhaust duct 400 is airtightly sealed.

[0050] In some embodiments, it is preferable that the exhaust duct 400 protrudes further away from the energy storage device 100 than the terminal covers 30c, 40c. In this embodiment, as shown in Figure 5, it is preferable that the side of the exhaust duct 400 away from the energy storage device 100 (here, the upper wall portion 410b) is further away from the energy storage device 100 than the outer surface of the terminal covers 30c, 40c (here, it is above). This allows the bridging member 450 to efficiently press the exhaust duct 400, making it easier to press the exhaust duct 400 firmly towards the energy storage device 100.

[0051] The bridging member 450 is a member that presses the exhaust duct 400 against the energy storage device 100 side (the lower side in Figure 5). The bridging member 450 is in contact with the upper wall portion 410b of the exhaust duct 400. In the first energy storage module 500A, the bridging member 450 is an example of a "pressing member that presses the exhaust duct against the energy storage device side". The bridging member 450 is preferably made of a highly rigid material such as metal or ceramic. This makes it easier to strongly press the exhaust duct 400. As shown in Figure 5, the bridging member 450 has a roughly U-shaped cross-section. This allows it to exhibit spring properties, making it easier to stably press the exhaust duct 400 even if vibrations are applied to the first energy storage module 500A. In this case, the bridging member 450 is made of a metal plate and is a "stay" having holes 450h at both ends in the second direction Y. The bridging member 450 extends in the second direction Y (the direction intersecting the arrangement direction X) here.

[0052] In this embodiment, the bridging member 450 is mechanically fixed to the restraint mechanism 300 (housing). Specifically, the restraint mechanism 300 (housing) has a pair of side plates 320 (a pair of wall members) extending along the arrangement direction X, and the bridging member 450 is fixed by inserting stud bolts 323 of the side plates 320 through holes 450h provided at both ends in the second direction Y, and fasteners (nuts, etc.) not shown. As a result, the bridging member 450 is spanned between the pair of side plates 320 (a pair of wall members). In other words, the bridging member 450 is spanned in a direction intersecting the arrangement direction X. However, in other embodiments, the bridging member 450 may be a member extending in the arrangement direction X and spanned between a pair of end plates 310. In other words, the bridging member 450 may be spanned in the arrangement direction X.

[0053] As shown in Figure 3, in this embodiment, there are multiple (specifically three) bridging members 450. The multiple bridging members 450 are arranged at predetermined intervals in the arrangement direction X. The multiple bridging members 450 are arranged at equal intervals in the arrangement direction X. This makes it easier to evenly press the upper wall portion 410b of the exhaust duct 400 in the planar direction. In this embodiment, the multiple bridging members 450 have the same configuration (e.g., structure, shape, size). However, in other embodiments, the multiple bridging members 450 may differ from each other in configuration (e.g., at least one of structure, shape, or size). Also, in other embodiments, there may be only one bridging member 450.

[0054] Figure 6 is a diagram corresponding to Figure 5 showing multiple second energy storage modules 500B. As shown in Figure 6, the multiple second energy storage modules 500B are arranged symmetrically in the second direction Y. The positions of the terminal covers 30c and 40c are reversed between the first second energy storage module 500B and the second second energy storage module 500B. The second energy storage module 500B has a plate-shaped member 460 instead of the bridging member 450 described above. In the second energy storage module 500B, the plate-shaped member 460 is an example of a "pressing member that presses the exhaust duct toward the energy storage device."

[0055] The plate-shaped member 460 is preferably made of metal, for example. In this embodiment, the plate-shaped member 460 is a single member that serves as both the pressing member for the first second energy storage module 500B and the pressing member for the second second energy storage module 500B. This reduces the number of parts, thereby lowering processing time and costs. However, in other embodiments, there may be multiple plate-shaped members 460, one for the first second energy storage module 500B and one for the second second energy storage module 500B.

[0056] The plate-shaped member 460 of this embodiment has a flat base portion 469 that extends along the surface (sealing plate 14) on which the gas discharge valve 17 of the energy storage device 100 is provided, a protruding portion 460p provided on the base portion 469, and a support portion 460s that supports the base portion 469. The support portion 460s is fixed to the stud bolts 323 of the side plate 320. The base portion 469 is arranged to cover a plurality of second energy storage modules 500B. In a plan view, the base portion 469 covers the entire plurality of second energy storage modules 500B. In some embodiments, other members, such as the control unit of the energy storage module 500, may be placed on the upper surface of the base portion 469 (the surface away from the energy storage device 100). This saves space and makes it easier to press the exhaust duct 400 firmly against the energy storage device 100 by utilizing the load of the placed member.

[0057] The protruding portion 460p protrudes toward the energy storage device 100 side (the lower side in Figure 6) and is the part (pressing portion) that presses the exhaust duct 400 toward the energy storage device 100 side. The protruding portion 460p is in contact with the exhaust duct 400 (specifically the upper wall portion 410b). Here, the protruding portion 460p is provided integrally with the base portion 469. That is, the protruding portion 460p is a part of the base portion 469 that has been deformed toward the energy storage device 100 side. However, in other embodiments, the protruding portion 460p may be a separate component from the base portion 469. Here, the protruding portion 460p has a roughly V-shaped cross-section. However, the cross-sectional shape of the protruding portion 460p can also be, for example, roughly U-shaped or roughly U-shaped. The number of protruding portions 460p here is the same as the number of second energy storage modules 500B (specifically the number of exhaust ducts 400). In other words, there are multiple (specifically two) in this case.

[0058] As can be seen from Figure 3, in this embodiment, the multiple protrusions 460p each extend linearly along the arrangement direction X. The multiple protrusions 460p each extend along the exhaust duct 400. However, the protrusions 460p may have shapes other than linear. The protrusions 460p may be composed of multiple parts scattered along the arrangement direction X, for example. Alternatively, the plate-shaped member 460 may not have protrusions 460p and may be configured to directly press against the exhaust duct 400 with the base portion 469.

[0059] As described above, in the technology disclosed herein, the exhaust duct 400 is pressed towards the energy storage device 100 by a pressing member (bridge member 450 or plate-shaped member 460). As a result, even if a large amount of gas is ejected from the gas discharge valve 17 of the energy storage device 100, the exhaust duct 400 is less likely to separate from the gas discharge valve 17. Therefore, a sealed state between the gas discharge valve 17 and the exhaust duct 400 can be suitably maintained.

[0060] Furthermore, from the perspective of improving the sealing performance between the gas discharge valve 17 and the exhaust duct 400, it is conceivable to mechanically fix the exhaust duct 400 at numerous points using, for example, numerous fasteners (screws, etc.). However, if too many fasteners are used, there are concerns about increased costs due to the increased number of parts, and decreased workability and productivity due to increased processing time. In this regard, by using the technology disclosed herein (the pressing member described above), the number of fasteners (screws, etc.) used to attach the exhaust duct 400 can be reduced, and consequently, processing time can also be reduced. Therefore, it becomes easier to balance sealing performance and productivity at a high level. It also becomes easier to achieve cost reduction.

[0061] The energy storage module 500 and energy storage pack 800 disclosed herein can be used for various applications, but are particularly suitable for use as a power source (driving power supply) for motors mounted on vehicles such as passenger cars and trucks. The type of vehicle is not particularly limited, but examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs).

[0062] Although preferred embodiments of the present invention have been described above, these embodiments are merely examples. The present invention can be implemented in various other forms. The present invention can be implemented based on the contents disclosed herein and common technical knowledge in the art. The technologies described in the claims include various modifications and changes to the embodiments illustrated above.

[0063] <First Modification> In the above-described embodiment, a bridging member 450 (in the case of the first energy storage module 500A) or a plate-shaped member 460 (in the case of the second energy storage module 500B) was used as the pressing member. However, it is not limited to this. In the modification, the cover body 620 of the pack case 600 described above may also serve as the pressing member. In this case, the cover body 620 may have a portion (pressing portion) that protrudes toward the energy storage device 100 side, such as the protruding portion 460p of the plate-shaped member 460, and presses the exhaust duct 400 toward the energy storage device 100 side. Since the cover body 620 also serves as the pressing member, there is no need to prepare a separate pressing member, which makes it possible to further improve productivity and reduce costs.

[0064] <Second Modification> In the above-described embodiment, the case body 12 was a bottomed rectangular tube with an opening at only one end. Also, there was one sealing plate 14. However, it is not limited to this. In the modified battery case, the case body may be a rectangular tube with openings at both ends. In this case, there may be two sealing plates. Also, the gas discharge valve 17 may be provided on one of the sealing plates, for example, or on the case body.

[0065] As described above, specific embodiments of the technology disclosed herein include those described in the following sections. Item 1: A power storage module comprising: a plurality of power storage devices arranged along the direction of arrangement; a housing for housing the plurality of power storage devices; gas discharge valves provided on each of the plurality of power storage devices; exhaust ducts extending along the direction of arrangement so as to cover the plurality of gas discharge valves of the plurality of power storage devices and positioned on the outer surface of the plurality of power storage devices; and a pressing member for pressing the exhaust ducts toward the power storage devices. Item 2: The energy storage module according to Item 1, wherein the housing is composed of a restraining mechanism that restrains a plurality of the energy storage devices in the direction of the arrangement. Item 3: The energy storage module according to item 1 or 2, wherein the pressing member is mechanically fixed to the housing. Item 4: The energy storage module according to any one of items 1 to 3, wherein the housing has a pair of wall members arranged opposite each other, and the pressing member is composed of a bridging member spanning across the pair of wall members. Item 5: The energy storage module according to Item 4, wherein the pair of wall members are a pair of side plates extending along the arrangement direction, and the bridging member spans in a direction intersecting the arrangement direction. Item 6: The energy storage module according to any one of items 1 to 3, wherein the pressing member is composed of a plate-shaped member that extends along the surface on which the gas discharge valves of the plurality of energy storage devices are provided. Item 7: The energy storage module according to any one of items 1 to 6, wherein each of the multiple energy storage devices has an electrode terminal on the surface on which the gas exhaust valve is provided, and further comprises a terminal cover extending along the arrangement direction so as to cover the multiple electrode terminals, and the exhaust duct protrudes on the side further away from the energy storage devices than the terminal cover. Item 8: A power storage pack comprising a plurality of power storage modules as described in Item 1 or 2, and a pack case for housing the plurality of power storage modules, wherein the pack case comprises a pack case body having an opening and a cover body covering the opening, the cover body also serving as the pressing member. [Explanation of symbols]

[0066] 14 Sealing plate 17 Gas discharge valve 30c, 40c terminal cover 100 Energy Storage Devices 200 Spacer 300 Restraint mechanism (housing) 310 End plate (wall component) 320 Side Plate (Wall Component) 400 Exhaust Duct 450 Bridge-linking member (pressing member) 460 Plate-shaped member (pressing member) 500 Energy Storage Modules 500A First Energy Storage Module 500B Second Energy Storage Module 600 pack case 620 Cover body (pressing member) 700 exhaust pipe 800 Battery Storage Pack X-axis orientation

Claims

1. Multiple energy storage devices arranged along the direction of the arrangement, A housing for housing multiple of the aforementioned energy storage devices, Each of the multiple energy storage devices is provided with a gas discharge valve, An exhaust duct extending along the arrangement direction so as to cover the gas exhaust valves of the plurality of energy storage devices and positioned on the outer surface of the plurality of energy storage devices, A pressing member that presses the exhaust duct against the energy storage device, A battery storage module equipped with the following features.

2. The housing is composed of a restraining mechanism that restrains a plurality of the energy storage devices in the direction of the arrangement. The energy storage module according to claim 1.

3. The pressing member is mechanically fixed to the housing. The energy storage module according to claim 1.

4. The housing has a pair of wall members arranged opposite each other, The pressing member is composed of a bridging member that spans across the pair of wall members. The energy storage module according to claim 3.

5. The pair of wall members are a pair of side plates extending along the direction of arrangement, The aforementioned bridging member is spanned in a direction intersecting the aforementioned arrangement direction. The energy storage module according to claim 4.

6. The pressing member is composed of a plate-shaped member that extends along the surface on which the gas discharge valves of the plurality of energy storage devices are provided. The energy storage module according to claim 3.

7. Each of the multiple energy storage devices is provided with electrode terminals on the surface where the gas discharge valve is located. The device further comprises a terminal cover extending along the arrangement direction so as to cover a plurality of the electrode terminals, The exhaust duct protrudes from the terminal cover on the side further away from the energy storage device. The energy storage module according to claim 1.

8. A plurality of energy storage modules according to claim 1, A pack case for housing the aforementioned multiple energy storage modules, Equipped with, The pack case comprises a pack case body having an opening and a cover body covering the opening. The cover body also serves as the pressing member. Energy storage pack.

Images