Power storage module, and power storage unit

Abstract

To provide a power storage module capable of being punctured when the pack expands without shorting the electrode stack and without any cost, and a power storage unit.SOLUTION: A power storage unit 1 and a power storage module 2 include: an energy storage device 10 that has a pack 11 made of laminated film and an electrode laminate 12 contained in the pack 11; a case 20 that holds the energy storage device 10; and a blade member 24 provided in the case 20 and serves to open a hole in the expanded portion of the pack 11 when the pack 11 is expanded. The portion of the pack 11 to be perforated by the blade member 24 is a portion where the electrode laminate 12 does not exist.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage module having an electricity storage device such as a lithium ion capacitor, and an electricity storage unit including the same. [Background technology]

[0002] In automobiles, electrical appliances, and the like, secondary batteries or capacitors are used as chargeable and dischargeable electricity storage devices. The electricity storage device is held in a case to form an electricity storage module. In addition, an electricity storage unit is formed by unitizing the electricity storage module and a circuit board.

[0003] In recent years, development of nonaqueous electrolytic electricity storage devices that can be charged and discharged by the movement of lithium ions between a positive electrode and a negative electrode has been progressing as electricity storage devices. Lithium ion batteries and lithium ion capacitors are known as electricity storage devices of this type. For example, lithium ion capacitors are used as backup power sources for electric power steering in automobiles.

[0004] A lithium ion battery or lithium ion capacitor includes an electrode laminate in which a positive electrode, a negative electrode, and a separator are laminated, and a pack (container) made of a laminate film that houses the electrode laminate.

[0005] In an electricity storage device with such a configuration, if the device is exposed to a high temperature environment or is overcharged, gas may be generated inside the pack. When gas is generated inside the pack, the internal pressure of the pack increases, causing the pack to expand. This may result in the pack exploding.

[0006] In view of this, a technique has been proposed in the past in which a metal frame with sharp metal protrusions is wrapped around the pack of an electricity storage device (Patent Document 1). With this configuration, when the pack expands, the protrusions can pierce the laminate film that constitutes the exterior body of the pack, creating holes in the pack. This allows gas inside the pack to escape when the pack expands, preventing the pack from exploding. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2012-74300 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the technology disclosed in Patent Document 1, when a hole is made in the pack with the protrusion, the protrusion may pierce the electrode laminate, causing a short circuit in the electrode laminate. In other words, there is a risk of a short circuit between the positive and negative electrodes constituting the electrode laminate. In particular, in Patent Document 1, since the protrusion is made of metal, if the protrusion pierces the electrode laminate, the electrode laminate will be short-circuited. In addition, in the technology disclosed in Patent Document 1, it is necessary to provide a metal frame in addition to the case that holds the electricity storage device, which is costly.

[0009] The present disclosure has been made to solve such problems, and aims to provide an energy storage module and an energy storage unit that can drill holes in the pack when the pack expands without shorting out the electrode stack and without incurring costs. [Means for solving the problem]

[0010] In order to achieve the above object, one aspect of the energy storage module according to the present disclosure comprises an energy storage device having a pack made of a laminate film and an electrode stack contained in the pack, a case for holding the energy storage device, and a blade member provided in the case for punching a hole in an expanding portion of the pack when the pack expands, wherein the portion of the pack through which a hole is punched by the blade member is a location where the electrode stack is not present.

[0011] Moreover, one aspect of an energy storage unit according to the present disclosure includes the above-mentioned energy storage module, a circuit board on which electronic components for controlling an energy storage device in the energy storage module are mounted, and a housing that houses the energy storage module and the circuit board. Effect of the Invention

[0012] The present disclosure allows the pack to be punctured when it expands without shorting out the electrode stack and without incurring costs. [Brief description of the drawings]

[0013] [Figure 1] 1 is a perspective view of an electricity storage unit according to an embodiment when viewed obliquely from above. FIG. [Diagram 2] 2 is a perspective view of the electricity storage unit according to the embodiment when viewed obliquely from below. FIG. [Diagram 3] 4 is an exploded perspective view of the electricity storage unit according to the embodiment with a second outer cover of the housing removed. FIG. [Figure 4] 11 is an exploded perspective view of the energy storage unit according to the embodiment when the energy storage module is removed from the second outer cover of the housing. FIG. [Diagram 5] FIG. 2 is an exploded perspective view of the electricity storage module according to the embodiment. [Figure 6] 2 is a cross-sectional view in a longitudinal direction of the electricity storage unit according to the embodiment. FIG. [Figure 7] 2 is a cross-sectional view in a short side direction of the electricity storage unit according to the embodiment. FIG. [Figure 8]1 is an external perspective view of an electricity storage device according to an embodiment; [Figure 9] 1 is a cross-sectional perspective view of an electricity storage device according to an embodiment. [Figure 10] FIG. 2 is a cross-sectional perspective view of the electricity storage unit according to the embodiment. [Figure 11] 10 is a plan view showing a positional relationship between blade members of a case and an electricity storage device in an electricity storage unit according to an embodiment. FIG. [Figure 12] 5 is a cross-sectional view in the longitudinal direction of the electricity storage unit when a first electricity storage device is expanded. FIG. [Figure 13] 5 is a cross-sectional view in the short side direction of the electricity storage unit when a first electricity storage device is expanded. FIG. [Figure 14] 10 is a cross-sectional view in the longitudinal direction of the electricity storage unit when the second electricity storage device is expanded. FIG. [Figure 15] 10 is a cross-sectional view in the short side direction of the electricity storage unit when a second electricity storage device is expanded. FIG. [Figure 16] 13 is a plan view showing the positional relationship between blade members of a case and an electricity storage device in an electricity storage unit according to Modification 1. FIG. [Figure 17] 13 is a plan view showing the positional relationship between blade members of a case and an electricity storage device in an electricity storage unit according to Modification 2. FIG. [Figure 18] 13 is a plan view showing the positional relationship between blade members of a case and an electricity storage device in an electricity storage unit according to Modification 3. FIG. [Figure 19] 13 is a plan view showing the positional relationship between blade members of a case and an electricity storage device in an electricity storage unit according to a fourth modified example. FIG. [Figure 20] FIG. 13 is a partially enlarged cross-sectional view of an electricity storage unit according to a fifth modified example. [Figure 21] FIG. 13 is a partially enlarged cross-sectional view of an electricity storage unit according to a sixth modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present disclosure. Therefore, the numerical values, components, the arrangement and connection of the components, the steps, and the order of the steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components that are not described in the independent claims will be described as optional components.

[0015] Note that each figure is a schematic diagram and is not necessarily a precise illustration. In addition, in each figure, substantially the same configuration is given the same reference numeral, and duplicated explanations are omitted or simplified. In addition, in this specification, the terms "upper" and "lower" do not necessarily refer to the upper direction (vertically upward) and the lower direction (vertically downward) in absolute spatial recognition.

[0016] (Embodiment) The energy storage unit 1 according to the embodiment will be described with reference to Figs. 1 to 9. Figs. 1 and 2 are perspective views of the energy storage unit 1 according to the embodiment. Fig. 1 shows the appearance of the energy storage unit 1 when viewed obliquely from above, and Fig. 2 shows the appearance of the energy storage unit 1 when viewed obliquely from below. Figs. 3 and 4 are exploded perspective views of the energy storage unit 1. Fig. 3 shows a state in which the second outer cover 50b of the housing 50 is removed, and Fig. 4 shows a state in which the energy storage module 2 is removed from the second outer cover 50b. Fig. 5 is an exploded perspective view of the energy storage module 2 according to the embodiment. Figs. 6 and 7 are cross-sectional views of the energy storage unit 1. Fig. 6 shows a cross-section when the energy storage unit 1 is cut along the longitudinal direction, and Fig. 7 shows a cross-section when the energy storage unit 1 is cut along the lateral direction. Fig. 8 is an external perspective view of the energy storage device 10 in the energy storage unit 1, and Fig. 9 is a cross-sectional perspective view of the energy storage device 10.

[0017] As shown in Figs. 1 to 7, the electricity storage unit 1 includes an electricity storage device 10, a case 20 that holds the electricity storage device 10, and an inner cover 30 that covers the electricity storage device 10. The electricity storage device 10, the case 20, and the inner cover 30 configure an electricity storage module 2. In other words, the electricity storage module 2 includes the electricity storage device 10, the case 20, and the inner cover 30. The case 20 and the inner cover 30 configure outer members of the electricity storage module 2. The electricity storage module 2 in this embodiment is a thin electricity storage module that has a substantially rectangular parallelepiped shape as a whole.

[0018] The power storage unit 1 includes the power storage module 2 and a circuit board 40 on which electronic components for controlling the power storage device 10 in the power storage module 2 are mounted. The power storage unit 1 is a unit formed by combining the power storage module 2 and the circuit board 40.

[0019] The energy storage unit 1 further includes a housing 50 that houses the energy storage module 2 and the circuit board 40. Specifically, the housing 50 houses the energy storage device 10, the case 20, the inner cover 30, and the circuit board 40. The housing 50 constitutes an outer casing member of the energy storage unit 1.

[0020] The electricity storage unit 1 in this embodiment is a thin electricity storage unit that has a generally rectangular parallelepiped shape as a whole. The electricity storage unit 1 configured in this manner is used, for example, as a power source for an automobile or the like. As one example, the electricity storage unit 1 is used as a backup power source for an electric power steering of an automobile.

[0021] In the present embodiment, the energy storage module 2 includes two energy storage devices 10. One of the two energy storage devices 10 is a first energy storage device 10a located on the circuit board 40 side, and the other of the two energy storage devices 10 is a second energy storage device 10b located on the opposite side to the circuit board 40 side. Specifically, the first energy storage device 10a is located on the lower side of the case 20, and the second energy storage device 10b is located on the upper side of the case 20. The first energy storage device 10a and the second energy storage device 10b are electrically connected by a bus bar 60. In the present embodiment, the first energy storage device 10a and the second energy storage device 10b are connected in series. Note that the first energy storage device 10a and the second energy storage device 10b are the same, but this is not limited thereto.

[0022] In addition, since the power storage module 2 includes two power storage devices 10, the power storage unit 1 includes two internal covers 30. Specifically, the power storage unit 1 includes, as the internal covers 30, a first internal cover 30a that covers the first power storage device 10a and a second internal cover 30b that covers the second power storage device 10b. The first internal cover 30a is a lower cover that covers the first power storage device 10a located on the lower side, and the second internal cover 30b is an upper cover that covers the second power storage device 10b located on the upper side.

[0023] The electricity storage device 10 is a device that can be charged and discharged. In the present embodiment, the electricity storage device 10 is a nonaqueous electrolytic electricity storage device that can be charged and discharged by the movement of lithium ions between a positive electrode and a negative electrode. Specifically, the electricity storage device 10 is a lithium ion capacitor (LIC).

[0024] As shown in FIGS. 8 and 9, an electricity storage device 10 has a pack 11 made of a laminate film, an electrode stack 12 contained in the pack 11, and a pair of terminals 13 extended from the pack 11.

[0025] The pack 11 is a container constituting the exterior body of the electricity storage device 10. In this embodiment, the pack 11 uses a metal laminate film made of aluminum as an exterior film, and is formed into a bag shape by overlapping this metal laminate film and sealing the outer periphery in a strip shape. Therefore, the pack 11 is a pouch having a sealing portion 11a formed in a strip shape along the outer periphery of the metal laminate film, and is hermetically sealed by this sealing portion 11a. In this embodiment, the pack 11 is hermetically sealed by heat welding the metal laminate film along the outer periphery of the pack 11. In other words, the sealing portion 11a is a heat-welded portion where the metal laminate film is heat-welded. This sealing by heat welding is performed in a state where the electrode stack 12 and a pair of terminals 13 are sandwiched between the front and back laminate films.

[0026] The shape of the pack 11 when viewed from above is rectangular. In other words, the shape of the metal laminate film constituting the exterior film of the pack 11 when viewed from above is rectangular. In this embodiment, the exterior film of the pack 11 is made of aluminum, but this is not limited thereto. The exterior film of the pack 11 may be made of a metal material other than aluminum.

[0027] The electrode laminate 12 stored in the pack 11 has a structure in which a positive electrode, a negative electrode, and a separator are laminated. Specifically, the electrode laminate 12 has a structure in which positive electrodes and negative electrodes, each formed into a sheet shape, are alternately stacked with a separator interposed therebetween. Since the electricity storage device 10 in this embodiment is a lithium ion capacitor, for example, the positive electrode has a structure in which a positive electrode material made of a carbon material such as activated carbon is formed on a positive electrode current collector, and the negative electrode has a structure in which a negative electrode material made of a material capable of absorbing and releasing lithium ions (for example, a carbon material such as graphite-based carbon) is formed on a negative electrode current collector.

[0028] Although not shown, the electricity storage device 10 further has an electrolyte. Specifically, the pack 11 containing the electrode stack 12 is filled with the electrolyte. Since the electricity storage device 10 in this embodiment is a lithium ion capacitor, the electrolyte contains, for example, a lithium compound that is an electrolyte and a solvent.

[0029] The pair of terminals 13 are extraction electrodes drawn out from the pack 11. The pair of terminals 13 are electrically connected to the electrode laminate 12. Specifically, one of the pair of terminals 13 is a positive electrode terminal electrically connected to the positive electrode of the electrode laminate 12, and the other of the pair of terminals 13 is a negative electrode terminal electrically connected to the negative electrode of the electrode laminate 12.

[0030] Further, the pair of terminals 13 function as external connection terminals for electrically connecting the power storage device 10 to other components. In the present embodiment, each of the pair of terminals 13 is electrically connected to an electronic component mounted on the circuit board 40 via a bus bar 60. Specifically, for each of the two power storage devices 10, the bus bar 60 is coupled to each of the pair of terminals 13. Then, the bus bars 60 connected to each of the pair of terminals 13 in the two power storage devices 10 are connected to each other so that the two power storage devices 10 are connected in series. The bus bars 60 connected to each of the pair of terminals 13 in each power storage device 10 are electrically connected to the wiring of the circuit board 40. The bus bars 60 are fixed to the circuit board 40 by screws 72.

[0031] The electricity storage device 10 is held in a case 20. The case 20 is a holder for holding the electricity storage device 10. Specifically, the case 20 has a storage section 21 that stores the electricity storage device 10 in order to hold the electricity storage device 10. The electricity storage device 10 stored in the storage section 21 is fixed to the case 20.

[0032] The storage section 21 is composed of a side wall 22 that surrounds the periphery of the electricity storage device 10, and a support section 23 that supports the electricity storage device 10. The side wall 22 and the support section 23 are formed in a concave shape (box shape) having a bottom.

[0033] The side wall 22 is located on a side of the pack 11 of the electricity storage device 10. The side wall 22 surrounding the pack 11 has a frame shape when viewed from above. In the present embodiment, the pack 11 of the electricity storage device 10 has a rectangular shape when viewed from above, and therefore the side wall 22 also has a rectangular frame shape when viewed from above. Specifically, the side wall 22 has a rectangular frame shape when viewed from above.

[0034] The rectangular frame-shaped side wall 22 abuts against three of the four side surfaces of the pack 11 when the pack 11 of the electricity storage device 10 expands or before the pack 11 expands. In the present embodiment, the portions of the side wall 22 corresponding to three of the four sides are provided close to the side surface of the pack 11 of the electricity storage device 10 arranged in the storage section 21 with a gap therebetween, and therefore are not in contact with the side surface of the pack 11 before the pack 11 expands, but abut against the three of the four side surfaces of the pack 11 when the pack 11 expands. On the other hand, the portion of the side wall 22 corresponding to one of the sides other than the three of the four sides is provided away from the side surface of the pack 11 compared to the portion corresponding to the three sides of the side wall 22, and does not abut against the pack 11 either before or after the pack 11 expands. Specifically, the portions of the two short sides of the side wall 22 that face the short side of the pack 11 from which the pair of terminals 13 are pulled out are spaced apart from the side surface of the short side of the pack 11, and the portions of the side wall 22 that correspond to the two long sides and the remaining short side are close to the side surface of the pack 11.

[0035] In this embodiment, the side wall 22 has a double structure of a rectangular frame-shaped outer wall 22b and a frame-shaped inner wall 22a provided inside the outer wall 22b. The distance between the outer wall 22b and the inner wall 22a is constant around the entire circumference of the side wall 22. Between the outer wall 22b and the inner wall 22a, a plurality of connecting walls 22c are provided, which are connected to the outer wall 22b and the inner wall 22a. The plurality of connecting walls 22c are erected on the outer wall 22b and the inner wall 22a, and are provided at equal intervals around the entire circumference of the side wall 22. By configuring the side wall 22 in this manner, the strength of the side wall 22 can be improved.

[0036] The support portion 23 is a plate-like portion formed in a plate shape, and has a support surface that supports a main surface of the pack 11 of the electricity storage device 10. The electricity storage device 10 is placed on the support surface of the support portion 23. Note that the support portion 23 and the pack 11 may be in contact with each other, but this is not limited thereto. For example, another sheet member may be inserted between the support portion 23 and the pack 11.

[0037] In this embodiment, the case 20 holds two power storage devices 10, the first power storage device 10a and the second power storage device 10b. Therefore, the case 20 has two storage sections 21. Specifically, the two storage sections 21 are provided on the top and bottom of the case 20. That is, one of the two storage sections 21 is provided on the bottom side of the case 20, and the other of the two storage sections 21 is provided on the top side of the case 20. Therefore, for the two power storage devices 10 held in the case 20, one of the power storage devices 10 (the first power storage device 10a) is disposed on the bottom side of the case 20, and the other of the power storage devices 10 (the second power storage device 10b) is disposed on the top side of the case 20. In this embodiment, the support section 23 in the two storage sections 21 is common, and the two power storage devices 10, the first power storage device 10a and the second power storage device 10b, are disposed above and below each other via the support section 23. In other words, the first electricity storage device 10a and the second electricity storage device 10b are arranged in the case 20 with the support portion 23 sandwiched between them.

[0038] The case 20 is made of an insulating resin material. In this embodiment, the case 20 is made of polybutylene terephthalate (PBT). The case 20 is a resin molded product integrally formed by injection molding. The insulating resin material constituting the case 20 is not limited to PBT.

[0039] As shown in Fig. 5 and Fig. 6, the case 20 is provided with a blade member 24 for making a hole in an expanded portion of the pack 11 of the electricity storage device 10 when the pack 11 expands. Therefore, the blade member 24 has a shape that allows it to break through the pack 11. Therefore, it is preferable that the blade member 24 has a sharp tip at the tip. As shown in Fig. 6, in this embodiment, the cross-sectional shape of the blade member 24 is a substantially triangular shape with an acute angle at the tip. As an example, the cross-sectional shape of the blade member 24 is a substantially isosceles triangle.

[0040] The blade member 24 is provided in the storage section 21 of the case 20. Specifically, the blade member 24 is provided in the support section 23 of the storage section 21. The blade member 24 is formed so as to protrude from the support surface of the support section 23.

[0041] The blade member 24 is provided at a position where it does not pierce the electrode laminate 12 of the electricity storage device 10 when the pack 11 of the electricity storage device 10 expands and a hole is made in the expanded portion of the pack 11. In other words, the portion of the pack 11 where a hole is made by the blade member 24 is a portion where the electrode laminate 12 of the electricity storage device 10 does not exist. In this embodiment, the portion of the pack 11 where a hole is made by the blade member 24 is a portion between a pair of terminals 13 on the outer periphery of the pack 11. Therefore, as shown in Figs. 6 and 11, the blade member 24 is provided at a position facing the portion between the pair of terminals 13 on the outer periphery of the pack 11. Fig. 11 is a plan view showing the positional relationship between the blade member 24 of the case 20 and the electricity storage device 10. In Fig. 11, the electricity storage device 10 is indicated by a dashed line.

[0042] Moreover, the blade member 24 is provided at a position corresponding to a side surface of one of the four sides of the side wall 22 other than the three sides that come into contact when the pack 11 is expanded. Specifically, the blade member 24 is provided at a position adjacent to one of the two short sides of the side wall 22.

[0043] In the present embodiment, since two electricity storage devices 10 are held in the case 20, two blade members 24 are provided in the case 20. That is, a blade member 24 is provided in each of the two storage sections 21. The two blade members 24 correspond one-to-one to the two electricity storage devices 10. Specifically, one of the two blade members 24 is provided for punching holes in the pack 11 of the first electricity storage device 10a, and the other of the two blade members 24 is provided for punching holes in the pack 11 of the second electricity storage device 10b. As shown in FIG. 6 and FIG. 10, the two blade members 24 are provided at positions that face each other vertically with the support section 23 in between.

[0044] The blade member 24 is made of an insulating material. Specifically, the blade member 24 is made of an insulating resin material. In the present embodiment, the blade member 24 is a part of the case 20. Therefore, the blade member 24 is formed integrally with the case 20.

[0045] The electricity storage device 10 placed in the case 20 is covered with the internal cover 30 and fixed to the case 20. Specifically, the sealed portion 11a of the pack 11 of the electricity storage device 10 is sandwiched between the side wall 22 of the case 20 and the internal cover 30, and the case 20 and the internal cover 30 are fixed with screws 71, thereby fixing the electricity storage device 10 to the case 20.

[0046] In the present embodiment, two electricity storage devices 10, a first electricity storage device 10a and a second electricity storage device 10b, are held in the case 20, and therefore a first inner cover 30a and a second inner cover 30b are used as the inner cover 30. In this case, the lower main surface of the first electricity storage device 10a is covered by the first inner cover 30a, and the upper main surface of the second electricity storage device 10b is covered by the second inner cover 30b.

[0047] The first and second electricity storage devices 10a and 10b are held between the first and second inner covers 30a and 30b and the case 20. Specifically, the sealed portion 11a of the pack 11 of the first electricity storage device 10a is sandwiched between the lower side wall 22 of the case 20 and the first inner cover 30a, and the sealed portion 11a of the pack 11 of the second electricity storage device 10b is sandwiched between the upper side wall 22 of the case 20 and the second inner cover 30b. In this state, the first inner cover 30a, the case 20, and the second inner cover 30b are fastened together with the screws 71, whereby the first and second electricity storage devices 10a and 10b can be held in the case 20.

[0048] This also makes it possible to obtain an electricity storage module 2 in which the two electricity storage devices 10 (the first electricity storage device 10a and the second electricity storage device 10b), the case 20, and the two inner covers 30 (the first inner cover 30a and the second inner cover 30b) are integrated together.

[0049] Each of the first inner cover 30a and the second inner cover 30b is provided with a locking claw 31 formed in a recess formed in the outer surface of the case 20. This allows the first inner cover 30a and the second inner cover 30b to be temporarily fixed to the case 20 before the first inner cover 30a and the second inner cover 30b are screwed to the case 20.

[0050] Since the electricity storage module 2 in the present embodiment is thin, the vertical gap between the electricity storage device 10 and the inner cover 30 or the vertical gap between the electricity storage device 10 and the case 20 is narrowed. Specifically, the lower first electricity storage device 10a supported by the first inner cover 30a has a narrow gap between it and the support portion 23 of the case 20. Also, the upper second electricity storage device 10b supported by the support portion 23 of the case 20 has a narrow gap between it and the second inner cover 30b.

[0051] In addition, in this embodiment, since the power storage unit 1 is also thin, the gap between the power storage module 2 and the circuit board 40 is also narrowed. Specifically, the gap between the first inner cover 30a covering the underside of the first power storage device 10a and the circuit board 40 is narrowed to bring the circuit board 40 and the first inner cover 30a into close proximity. As an example, the gap between the circuit board 40 and the first inner cover 30a is about 2 to 3 mm.

[0052] The first inner cover 30a and the second inner cover 30b are made of an insulating resin material. Each of the first inner cover 30a and the second inner cover 30b is a resin molded product integrally formed by injection molding. In this embodiment, the first inner cover 30a and the second inner cover 30b are made of different insulating resin materials. Specifically, the lower (circuit board 40 side) first inner cover 30a is made of polyphenylene sulfide (PPS), and the upper second inner cover 30b is made of PBT, similar to the case 20. In addition, the rigidity of the first inner cover 30a is higher than the rigidity of the second inner cover 30b. This makes it possible to suppress deformation of the first inner cover 30a even if stress is applied to the first inner cover 30a. The insulating resin material constituting the first inner cover 30a and the second inner cover 30b is not limited to the above. Furthermore, the first inner cover 30a and the second inner cover 30b may be made of the same insulating resin material.

[0053] The inner cover 30 and the circuit board 40 are covered by a housing 50. The housing 50 is an outer cover that covers the inner cover 30. In this embodiment, the housing 50 has a first outer cover 50a that covers the first inner cover 30a, and a second outer cover 50b that covers the second inner cover 30b. In other words, the first outer cover 50a is a lower cover that covers the first inner cover 30a located on the lower side, and the second outer cover 50b is an upper cover that covers the second inner cover 30b located on the upper side.

[0054] A circuit board 40, on which electronic components are mounted, is disposed on the first outer cover 50a located on the lower side. The circuit board 40 is supported by the first outer cover 50a. The electronic components mounted on the circuit board 40 control, for example, charging and discharging of the electricity storage device 10.

[0055] The first outer cover 50a and the second outer cover 50b are metal covers made of metal materials. Specifically, the first outer cover 50a and the second outer cover 50b are made of sheet metal, and are made of metal plates such as aluminum alloy plates or steel plates. Specifically, the first outer cover 50a and the second outer cover 50b are press-molded products formed into a substantially box-like shape by performing roll forming and / or press working on a single metal plate. In this embodiment, both the first outer cover 50a and the second outer cover 50b are made of aluminum alloy plates.

[0056] The first outer cover 50a and the second outer cover 50b are formed in a rectangular box shape. Therefore, the top view shape of each of the first outer cover 50a and the second outer cover 50b is rectangular. The first outer cover 50a and the second outer cover 50b are fixed to each other by screws 73. The screws 71 that fasten the first inner cover 30a, the case 20, and the second inner cover 30b together are screwed into the screw holes of the first outer cover 50a.

[0057] The first outer cover 50a is provided with a connection socket 90. The connection socket 90 is provided with connection pins electrically connected to the wiring of the circuit board 40. A connector having a conductive wire electrically connected to an external device is inserted into the connection socket 90. A bracket 100 for fixing the energy storage unit 1 to an external member is fixed to the back surface of the first outer cover 50a.

[0058] Next, the effects of the electricity storage unit 1 configured in this manner will be described with reference to Figs. 12 to 15. Figs. 12 and 13 are cross-sectional views of the electricity storage unit 1 when the lower electricity storage device 10 (first electricity storage device 10a) is expanded, and Figs. 14 and 15 are cross-sectional views of the electricity storage unit 1 when the upper electricity storage device 10 (second electricity storage device 10b) is expanded. Figs. 12 and 14 show cross sections of the electricity storage unit 1 cut along the longitudinal direction, and Figs. 13 and 15 show cross sections of the electricity storage unit 1 cut along the lateral direction.

[0059] When the electricity storage device 10 is exposed to a high temperature environment or is in an overcharged state, gas is generated within the pack 11 of the electricity storage device 10, causing the pack 11 to expand.

[0060] 12 and 13, when the pack 11 of the lower first electricity storage device 10a expands, the pack 11 of the first electricity storage device 10a expands in all directions, but in this embodiment, the first electricity storage device 10a is disposed in a narrow space between the first inner cover 30a and the case 20. For this reason, the pack 11 of the first electricity storage device 10a expands toward the blade member 24 while being restricted by the first inner cover 30a and the case 20.

[0061] Specifically, the support portion 23 of the case 20 and the first inner cover 30a are present in the up-down direction of the first electricity storage device 10a, and the side wall 22 of the case 20 is present on the side of the first electricity storage device 10a. Therefore, when the pack 11 of the first electricity storage device 10a expands, the upper and lower parts of the pack 11 are pressed down by the first inner cover 30a and the support portion 23 of the case 20. That is, the expansion of the pack 11 of the first electricity storage device 10a in the up-down direction is restricted by the first inner cover 30a and the support portion 23 of the case 20. As a result, the pack 11 of the first electricity storage device 10a expands in the lateral direction (horizontal direction).

[0062] At this time, since the first electricity storage device 10a is surrounded by the side wall 22, when the pack 11 of the first electricity storage device 10a expands laterally, the outer peripheral portion of the pack 11 abuts against the side wall 22, so that the expansion in the lateral direction is also restricted.

[0063] In this case, in the present embodiment, the portion of the two short sides of the side wall 22 of the case 20 facing the short side on the terminal 13 side of the pack 11 is farther away from the side surface of the pack 11 than the portions corresponding to the two long sides and the other short sides of the side wall 22. Therefore, the pack 11 expanding in the lateral direction is restricted in its lateral expansion by having the outer peripheral portion corresponding to the short side opposite to the short side on the terminal 13 side and the two long sides abut against the side wall 22 before the outer peripheral portion corresponding to the short side on the terminal 13 side. In other words, the case 20 and the first inner cover 30a are structured such that the outer peripheral portion corresponding to the short side on the terminal 13 side of the pack 11 of the first electricity storage device 10a promotes expansion compared to other portions. As a result, the pack 11 of the first electricity storage device 10a expands toward the blade member 24 provided corresponding to the short side on the terminal 13 side of the pack 11.

[0064] Then, when the expanded portion of the pack 11 of the first electricity storage device 10a reaches the blade member 24, the blade member 24 pierces the expanded portion of the pack 11, and a hole is made in the pack 11. Specifically, due to a reaction force generated when the pack 11 pushes the blade member 24 due to the expansion, the tip of the blade member 24 breaks through the pack 11, and a hole is made in the pack 11. Since the first electricity storage device 10a is located on the lower side, the portion of the pack 11 of the first electricity storage device 10a where the hole is made by the blade member 24 is the upper surface of the pack 11. In this way, by making the portion where the hole is made by the blade member 24 the upper surface of the pack 11, it is possible to prevent the electrolyte in the pack 11 from flowing out, and it is possible to prevent secondary damage and the like.

[0065] In the present embodiment, since the power storage module 2 has a thin structure, the vertical gap between the first power storage device 10a and the case 20 is narrow. Furthermore, since the power storage unit 1 also has a thin structure, the gap between the power storage module 2 and the circuit board 40 is also narrow. Specifically, the gap between the first inner cover 30a covering the underside of the first power storage device 10a and the circuit board 40 is narrowed to bring the circuit board 40 and the first inner cover 30a into close proximity.

[0066] For this reason, when the pack 11 of the first electricity storage device 10a expands, the expanding pack 11 presses against the first inner cover 30a. As a result, as shown in Figs. 12 and 13, the first inner cover 30a is curved so as to be convex toward the circuit board 40 (lower side).

[0067] Next, a case where the pack 11 of the upper second electricity storage device 10b expands will be described with reference to FIGS.

[0068] As shown in Figs. 14 and 15, when the pack 11 of the second electricity storage device 10b expands, holes are made in the pack 11 of the second electricity storage device 10b by the blade members 24, similar to the pack 11 of the first electricity storage device 10a.

[0069] At this time, the pack 11 of the second electricity storage device 10b is disposed in the narrow space between the second inner cover 30b and the case 20, and therefore expands toward the blade member 24 while being restricted by the second inner cover 30b and the case 20, similar to the pack 11 of the first electricity storage device 10a.

[0070] Specifically, the support portion 23 of the case 20 and the second inner cover 30b are present in the up-down direction of the second electricity storage device 10b, and the side wall 22 of the case 20 is present on the side of the second electricity storage device 10b. Therefore, when the pack 11 of the second electricity storage device 10b expands, the upper and lower parts of the pack 11 are pressed down by the second inner cover 30b and the support portion 23 of the case 20. In other words, the expansion of the pack 11 of the second electricity storage device 10b in the up-down direction is restricted by the second inner cover 30b and the support portion 23 of the case 20. As a result, the pack 11 of the second electricity storage device 10b also expands in the lateral direction (horizontal direction).

[0071] At this time, since the second electricity storage device 10b is surrounded by the side wall 22, when the pack 11 of the second electricity storage device 10b expands laterally, the outer peripheral portion of the pack 11 abuts against the side wall 22, so that the expansion in the lateral direction is also restricted.

[0072] In this case, the upper side wall 22 of the case 20, like the lower side wall 22, has a portion of the two short sides facing the short side on the terminal 13 side of the pack 11 that is farther away from the side surface of the pack 11 than the portions corresponding to the two long sides and the other short sides of the side wall 22. Therefore, the pack 11 of the second electricity storage device 10b that expands in the lateral direction is restricted in its lateral expansion by having the outer peripheral portion corresponding to the short side opposite to the short side on the terminal 13 side and the two long sides abut against the side wall 22 before the outer peripheral portion corresponding to the short side on the terminal 13 side. In other words, the case 20 and the second inner cover 30b are structured such that the outer peripheral portion corresponding to the short side on the terminal 13 side of the pack 11 of the second electricity storage device 10b promotes expansion compared to other portions. As a result, the pack 11 of the second electricity storage device 10b expands toward the blade member 24 provided in correspondence with the short side on the terminal 13 side of the pack 11.

[0073] Then, when the expanding portion of the pack 11 of the second electricity storage device 10b reaches the blade member 24, similar to the pack 11 of the first electricity storage device 10a, the blade member 24 pierces the expanding portion of the pack 11 and makes a hole in the pack 11. Note that since the second electricity storage device 10b is located on the upper side, the portion of the pack 11 of the second electricity storage device 10b where the hole is made by the blade member 24 is the lower surface of the pack 11.

[0074] In this manner, according to the electricity storage unit 1 of the present embodiment, when the pack 11 of the electricity storage device 10 expands, the blade members 24 can pierce the expanded portion of the pack 11 and make a hole in the pack 11.

[0075] At this time, in the energy storage unit 1 and energy storage module 2 of this embodiment, the blade member 24 is provided on the case 20, and the portion (expanded portion) in the pack 11 of the energy storage device 10 where a hole is made by the blade member 24 is a portion where the electrode stack 12 of the energy storage device 10 is not present.

[0076] In this way, the portion of the pack 11 of the electricity storage device 10 where the hole is made by the blade member 24 is a portion where the electrode stack 12 of the electricity storage device 10 is not present, so that when the pack 11 of the electricity storage device 10 expands and a hole is made in the pack 11 by the blade member 24, the electrode stack 12, which is the internal structure of the electricity storage device 10, is not scratched by the blade member 24. In other words, the blade member 24 does not come into contact with the electrode stack 12 even after making a hole in the expanded pack 11. This makes it possible to prevent the blade member 24 from piercing the electrode stack 12 and causing a short circuit in the electrode stack 12. Moreover, because the blade member 24 is provided in the case 20, explosion-proof measures for the electricity storage device 10 can be implemented at low cost.

[0077] As described above, according to the electricity storage unit 1 and the electricity storage module 2 of the present embodiment, when the pack 11 of the electricity storage device 10 expands, holes can be opened in the pack 11 of the electricity storage device 10 to allow gas inside the pack 11 to escape without shorting the electrode stack 12 of the electricity storage device 10 and without incurring costs. This makes it possible to prevent the pack 11 from expanding and bursting.

[0078] In the above embodiment, the case where only the pack 11 of the lower first electricity storage device 10a expands (FIGS. 12 and 13) and the case where only the pack 11 of the upper second electricity storage device 10b expands (FIGS. 14 and 15) have been described separately, but there are also cases where the pack 11 of the first electricity storage device 10a and the pack 11 of the second electricity storage device 10b expand at the same time.

[0079] Furthermore, in the energy storage unit 1 and energy storage module 2 of this embodiment, the pack 11 of the energy storage device 10 has a rectangular shape when viewed from above, the case 20 has side walls 22 that abut against the side surfaces of three of the four sides of the pack 11 when the pack 11 expands, and the blade member 24 is provided at a position corresponding to the side surface of one of the four sides of the pack 11 other than the three sides.

[0080] With this configuration, when the pack 11 of the electricity storage device 10 expands, the lateral expansion of the pack 11 is restricted by the side wall 22 of the case 20. Specifically, the side wall 22 of the case 20 allows the pack 11 to expand toward the blade member 24 provided at a position corresponding to the side surface of one of the four sides of the pack 11 other than three sides. In other words, the side wall 22 of the case 20 functions as a guide portion that guides the pack 11 to expand toward the blade member 24. As a result, the pack 11 of the electricity storage device 10 can be expanded at a targeted position and pressed strongly against the blade member 24, so that even if the blade member 24 is made of resin rather than metal, a hole can be effectively made in the pack 11.

[0081] Furthermore, in the electricity storage unit 1 and the electricity storage module 2 according to the present embodiment, an inner cover 30 is provided that comes into contact with one main surface of the pack 11 of the electricity storage device 10 when the pack 11 expands, and the case 20 supports the other main surface of the pack 11. In other words, the pack 11 is disposed between the inner cover 30 and the case 20.

[0082] With this configuration, when the pack 11 of the electricity storage device 10 expands, the expansion of the pack 11 in the vertical direction is restricted by the case 20 and the internal cover 30. Specifically, the expansion of the pack 11 in the vertical direction is suppressed by the support portion 23 of the case 20 and the internal cover 30, and the pack 11 can be encouraged to expand in the lateral direction. This allows the pack 11 to expand toward the blade member 24 arranged on the side of the pack 11. In other words, the support portion 23 of the case 20 and the internal cover 30 function as a guide portion that guides the pack 11 to expand toward the blade member 24. This allows the pack 11 of the electricity storage device 10 to expand at a targeted position and be strongly pressed against the blade member 24, so that even if the blade member 24 is made of resin rather than metal, a hole can be effectively made in the pack 11.

[0083] Furthermore, in the energy storage unit 1 and energy storage module 2 of this embodiment, the pack 11 of the energy storage device 10 is hermetically sealed by heat-sealing a laminate film along the outer peripheral edge of the pack 11, and the portion of the pack 11 that is perforated by the blade member 24 is the location between a pair of terminals pulled out from the pack 11.

[0084] The electrode laminate 12 is not present between the pair of terminals 13 in the pack 11. Therefore, by opening a hole with the blade member 24 at the location between the pair of terminals 13 in the pack 11, it is possible to prevent the blade member 24 from piercing the electrode laminate 12 when a hole is opened by the blade member 24 in the expanded pack 11.

[0085] (Modification) Although the technology of the present disclosure has been described above based on the embodiments, the present disclosure is not limited to the above-described embodiments.

[0086] For example, in the electricity storage unit 1 in the above embodiment, the blade member 24 is provided at a position facing a portion between a pair of terminals 13 on a short side of the outer periphery of the pack 11 of the electricity storage device 10, but this is not limited thereto. Specifically, as in the electricity storage unit 1A shown in Fig. 16, the blade member 24 may be provided at a position facing a corner of the outer periphery of the pack 11 of the electricity storage device 10. Alternatively, as in the electricity storage unit 1B shown in Fig. 17, the blade member 24 may be provided at a position facing a long side of the outer periphery of the pack 11 of the electricity storage device 10, or as in the electricity storage unit 1C shown in Fig. 18, the blade member 24 may be provided at a position facing a short side of the outer periphery of the pack 11 of the electricity storage device 10 opposite to the short side on the terminal 13 side.

[0087] In the energy storage unit 1 in the above embodiment, one blade member 24 is provided for one energy storage device 10, but this is not limited to the above. For example, like an energy storage unit 1D shown in Fig. 19, a plurality of blade members 24 (three in Fig. 19) may be provided for one energy storage device 10.

[0088] In the electricity storage unit 1 in the above embodiment, the cross-sectional shape of the blade member 24 is a substantially isosceles triangle, but is not limited thereto. For example, as in the electricity storage unit 1E shown in FIG. 20, the cross-sectional shape of the blade member 24E of the case 20E may be a right-angled triangle. In this case, the blade member 24E may be formed in the case 20E such that the right-angled portion faces the electricity storage device 10. As in the electricity storage unit 1F shown in FIG. 21, a sharp protrusion 24b protruding toward the electricity storage device 10 may be provided at the tip of the blade member 24F of the case 20F. This allows the protrusion 24b of the blade member 24F to easily break through the expanded pack 11, compared to a blade member 24 not provided with the protrusion 24b.

[0089] In the above embodiment, the power storage device 10 is a lithium ion capacitor, but is not limited to this. The power storage device 10 may be a capacitor other than a lithium ion capacitor. The power storage device 10 is not limited to a capacitor, but may be a secondary battery such as a lithium ion secondary battery.

[0090] In the above embodiment, the power storage unit 1 has two power storage devices 10, but this is not limited thereto. The power storage unit 1 may have one power storage device 10, or may have more than two power storage devices 10.

[0091] In the above embodiment, the power storage unit 1 is used in an automobile, but the present invention is not limited to this. For example, the power storage unit 1 can be applied to electric appliances and the like.

[0092] In addition, the present disclosure also includes forms obtained by applying various modifications to the above-mentioned embodiments that a person skilled in the art may conceive, and forms realized by arbitrarily combining the components and functions in the embodiments within the scope of the present disclosure. In addition, the present disclosure also includes any combination of two or more claims from among the multiple claims described in the claims at the time of filing of this application, within the scope of technical compatibility. For example, when a cited-form claim described in the claims at the time of filing of this application is made into a multiple claim or multiple multiple claim so as to cite all of the higher claims within the scope of technical compatibility, the present disclosure also includes a combination of all claims included in the multiple claim or multiple multiple claim. [Industrial Applicability]

[0093] The technology disclosed herein can be widely used in various products such as automobiles or electrical appliances. [Explanation of symbols]

[0094] 1, 1A, 1B, 1C, 1D, 1E, 1F Energy storage unit 2. Energy storage module 10. Energy storage devices 10a First power storage device 10b Second power storage device 11 Pack 11a Sealing part 12 Electrode laminate 13 Terminals 20, 20E, 20F Case 21 Storage area 22 Side wall 22a Inner wall 22b Outer wall 22c Connecting wall 23 Support part 24, 24E, 24F Blade material 24b protrusion 30 Inner cover 30a First inner cover 30b Second inner cover 31 Locking claw 40 Circuit Board 50 Case 50a First outer cover 50b Second outer cover 60 Busbar 71, 72, 73 Screws 90 Connection Socket 100 Bracket

Claims

1. an electricity storage device having a pack made of a laminate film and an electrode laminate contained in the pack; A case for holding the power storage device; and a blade member provided in the case for opening a hole in an expanded portion of the pack when the pack is expanded; The portion of the pack where the hole is opened by the blade member is a portion where the electrode stack is not present. Energy storage module.

2. The pack has a rectangular shape when viewed from above, the case has side walls that abut against three of the four sides of the pack when the pack is inflated or before the pack is inflated; The blade member is provided at a position corresponding to a side surface of one of the four sides other than the three sides. The energy storage module according to claim 1 .

3. Further, a cover is provided that abuts against one main surface of the pack when the pack is inflated or before the pack is inflated, The case supports the other main surface of the pack. The power storage module according to claim 2 .

4. The pack is hermetically sealed by heat sealing the laminate film along the outer periphery of the pack, the power storage device has a pair of terminals extending from the pack; The portion of the pack where the hole is opened by the blade member is a portion between the pair of terminals. The storage module according to any one of claims 1 to 3.

5. The portion of the pack that is perforated by the blade member is an upper surface of the pack. The storage module according to any one of claims 1 to 3.

6. The power storage device is a lithium ion capacitor. The storage module according to any one of claims 1 to 3.

7. The energy storage module according to any one of claims 1 to 3, a circuit board on which electronic components for controlling the power storage device in the power storage module are mounted; a housing that houses the power storage module and the circuit board, Energy storage unit.

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