Power storage module

Abstract

A power storage module (10) is provided with a plurality of power storage devices (20) and a case (30) that houses the plurality of power storage devices (20), the power storage devices (20) discharge internal gas toward one side in a first direction when an abnormality occurs, and a protection member (40) is provided on one side in the first direction of the power storage device (20) on one side in the first direction inside the case (30). A metal foam body (50) is provided on a surface of the protective member (40) facing the electricity storage device (20) in the first direction.

Description

Technical Field

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

[0002] In a power storage module, multiple power storage devices are housed in a housing. Each power storage device has an exhaust section that serves as a safety mechanism to vent internal gas in the event of an abnormality. For example, Patent Document 1 discloses a power storage module having a flame shield (protective member) that shields the exhaust gas when it is released from the exhaust section of the power storage device.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-169454 Summary of the Invention

[0006] The above-mentioned power storage module can ensure a certain degree of reliability. However, as power storage devices increase in capacity and output, the reliability of the power storage module needs to be further improved.

[0007] Therefore, an object of the present disclosure is to provide a power storage module capable of improving reliability.

[0008] The storage module disclosed herein comprises a plurality of storage devices and a housing for accommodating the plurality of storage devices, and is characterized in that the storage devices discharge internal gas toward one side in a first direction in the event of an abnormality, a protective member is provided on one side of the storage device in the first direction inside the housing, and a porous body having pores extending three-dimensionally is provided on a surface of the protective member in the first direction facing the storage device.

[0009] According to the power storage module of the present disclosure, reliability can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a perspective view showing a power storage module as an example of the embodiment.

[0011] Figure 2 Yes Figure 1 Schematic cross-sectional view of section AA.

[0012] Figure 3 It is a schematic cross-sectional view illustrating the flow of gas during an abnormality in the power storage device.

[0013] Figure 4 This is another example of a power storage module according to the embodiment. Figure 1 Schematic cross-sectional view of section AA. DETAILED DESCRIPTION

[0014] In the following description, specific shapes, materials, directions, numerical values, etc. are illustrative for easy understanding of the present disclosure and can be appropriately changed according to the application, purpose, specifications, etc.

[0015] [Electricity Storage Module]

[0016] use Figures 1 to 3 The power storage module 10 will be described.

[0017] The power storage module 10 is used, for example, as a power source for electric vehicles. However, the power storage device disclosed herein is not limited to power sources for electric vehicles. For example, it can also be used as a power source for motor-driven electric devices such as power tools, power-assisted bicycles, electric motorcycles, electric wheelchairs, electric tricycles, and electric scooters. Furthermore, the power storage device disclosed herein can also be used as a power source for various electrical devices used indoors and outdoors, such as cleaners, wireless devices, lighting devices, digital cameras, and video cameras.

[0018] like Figure 1 and Figure 2 As shown, the energy storage module 10 includes multiple energy storage devices 20 and a housing 30 that houses the multiple energy storage devices 20. In the event of an abnormality, the energy storage devices 20 discharge internal gas toward one side in the first direction (the longitudinal direction). A protective member 40 is provided on one side in the first direction of the energy storage device 20, which is located closest to the side in the first direction, within the housing 30. A metal foam 50, which is a porous body having three-dimensionally extending pores (through-holes), is provided on the other side in the first direction of the protective member 40. The metal foam 50 can improve the reliability of the energy storage module 10, as will be described in detail later.

[0019] [Electricity Storage Device]

[0020] The power storage device 20 is, for example, a cylindrical lithium-ion secondary battery having electrodes on both end faces in the first direction (the longitudinal direction). However, the power storage device of the present disclosure is not limited to the lithium-ion secondary battery of this embodiment and may also be another secondary battery such as a nickel-metal hydride battery, a nickel-cadmium battery, a lithium polymer battery, or a power storage device such as a capacitor. Furthermore, the power storage device of the present disclosure is not limited to the cylindrical shape of this embodiment and may also be a square shape.

[0021] The energy storage device 20 includes: an electrode group, which is formed by winding a positive electrode and a negative electrode in a state of facing each other with a separator in between; an outer can, which houses the electrode group together with the electrolyte and has a barrel and a bottom that seals one end of the barrel; and a sealing member that seals the opening at the other end of the outer can. The sealing member is electrically connected to one electrode of the positive electrode and the negative electrode via a lead wire or the like. The outer can is electrically connected to the other electrode of the positive electrode and the negative electrode via a lead wire or the like. An electrically insulating gasket is sandwiched between the sealing member and the outer can. The energy storage device 20 includes a vent 21 at least at one end in the first direction (the length direction or the height direction of the energy storage device 20).

[0022] The exhaust portion 21 exhausts gas from the power storage device 20 to the outside when an abnormality occurs. Specifically, the power storage device 20 exhausts gas toward one side in the first direction when an abnormality occurs. However, the exhaust portion 21 may be formed at both ends of the power storage device 20 in the first direction. For example, the exhaust portion 21 may be an irreversible valve that opens by rupturing an engraving, or a reversible valve that further compresses an already compressed elastic member using gas pressure to create an exhaust path.

[0023] Furthermore, in this embodiment, all of the electrical storage devices 20 housed in the housing 30 are housed with their exhaust portions 21 facing one side in the first direction. However, the plurality of electrical storage devices disclosed herein are not limited to this embodiment; it is sufficient that the electrical storage devices 20 are housed with the exhaust portion 21 of at least one electrical storage device 20 facing one side in the first direction. Furthermore, the electrical storage module 10 may include a holder for arranging and holding the plurality of electrical storage devices 20, although this is not shown.

[0024] [case]

[0025] The housing 30 houses and protects the energy storage device 20. The housing 30 includes a main body 31 having a cylindrical shape with its longitudinal direction extending in the first direction, and lids 32 and 33 that seal both ends of the main body 31 in the longitudinal direction. Alternatively, the housing 30 may include an annular seal sandwiched between the opening of the main body 31 and the lids 32 and 33, thereby sealing both openings with a waterproof structure. Furthermore, while the housing 30 uses a pair of lids 32 and 33 to seal both openings of the main body 31, the main body 31 may also be a bottomed, cylindrical structure with only one end face open, with the lid 32 sealing the end face opening alone.

[0026] The main body 31 is formed of a metal such as aluminum, which has strength and excellent heat dissipation. The main body 31 is not limited to metal if it is made of a heat-resistant material, and can also be made of resin. The main body 31 is formed into a cylindrical shape with a roughly rectangular cross-section in the first direction and a square cylindrical shape with both ends open. In addition, in order to increase the strength, grooves or protrusions can also be formed in the main body 31 along the longitudinal direction. In addition, in order to insulate the metal main body 31, the surface of the main body 31 can also be covered with a laminated film, vinyl resin, etc.

[0027] Covers 32 and 33 are formed of hard plastic. However, the cover disclosed herein is not limited to the hard plastic of this embodiment and may also be made of metal. Cover 32 is provided with an exhaust port 34, which will be described in detail later. One of covers 32 and 33 may also be provided with a discharge connector for discharging power from power storage device 20 or a charge connector for charging power storage device 20.

[0028] The exhaust port 34 connects the interior of the housing 30 housing the electrical storage device 20 to the exterior, and discharges the gas exhausted from the electrical storage device 20 from the interior to the exterior. The exhaust port 34 is provided on one side in the first direction. However, the exhaust port disclosed herein is not limited to this embodiment and may be provided on the other side in the first direction, or on one or both sides in a direction orthogonal to the first direction. A porous body 35 is provided on both sides of the exhaust port 34 in the first direction. However, the porous body 35 may also be provided on only one or both sides of the exhaust port 34 in the first direction.

[0029] The porous body 35 may be, for example, a punched metal aluminum plate with numerous through-holes. Each porous body 35 can be secured to the lid 32 using screws and bolts. The porous body 35 prevents particles of the contents of the power storage device 20 contained in the gas from being released outside the housing 30 along with the gas. Furthermore, as the gas passes through the porous body 35, heat from the gas is transferred to the porous body 35, cooling the passing gas.

[0030] [Protective components]

[0031] The protective member 40 is disposed within the housing 30 on one side in the first direction of the electrical storage device 20, which is positioned closest to the side in the first direction. In other words, the protective member 40 is interposed between the electrical storage device 20 closest to the lid 32 and the porous body 35 in the first direction. The protective member 40 shields gas and flames exhausted from the electrical storage device 20, preventing them from being directly blown toward the porous body 35, as will be described in detail later. Furthermore, the gas exhausted from the electrical storage device 20 is directed around the protective member 40 and toward the exhaust port 34.

[0032] When viewed from the first direction, the protective member 40 is formed into a generally rectangular shape that covers the plurality of power storage devices 20 housed in the housing 30. The protective member 40 is formed, for example, into a plate shape with a thickness of 1 mm or less. The protective member 40 may be made of a material having a higher melting point than that of the porous body 35. For example, the protective member 40 may be made of iron, stainless steel, or ceramic. The protective member 40 may also be secured to the lid 32 together with the porous body 35 using screws and bolts that secure the porous body 35, via spacers that define the gap between the protective member 40 and the porous body 35.

[0033] In addition, the protective member 40 is made of a material having an opening ratio smaller than that of the metal foam 50 described later or having no through holes, thereby being able to block the gas that passes through the metal foam 50 and then attempts to pass through the protective member 40 , thereby improving the filter function of the metal foam 50 .

[0034] [Metal foam]

[0035] The metal foam 50, a porous body having three-dimensionally extending pores (through-holes), is provided on the surface of the protective member 40 facing the power storage device 20 in the first direction. In other words, the metal foam 50 is provided on the first-direction side of the power storage device 20, which is located within the housing 30 and is positioned closest to the first-direction side. The metal foam 50 acts as a filter to capture the contents of the power storage device 20 and cool the gas when the power storage device 20 discharges gas in the event of an abnormality, thereby absorbing the impact of the gas and improving reliability. This will be described in detail later.

[0036] The metal foam 50, which is a porous body having three-dimensionally extending holes (through holes), is a cell-shaped structure of metal (stainless steel in this embodiment) having a large number of small spaces formed by gas. However, the metal foam disclosed in the present invention is not limited to the stainless steel of this embodiment, and may also be aluminum, nickel or copper. In addition, the bubble ratio of the metal foam 50 is preferably 80% to 90%. In the metal foam 50, the bubbles may be independent of each other or connected to each other. The metal foam 50 may also be fixed to the protective member 40 by an adhesive. As a fixing method other than the adhesive, the metal foam 50 may be fixed to the protective member 40 by screws, or the metal foam 50 may be clamped together with the protective member 40 by screws or the like. In addition, if the foam is metal, the foam may be riveted to the protective member 40 for mechanical fixing. In addition, the foam may be mounted on the protective member 40 by welding. In addition, examples of the porous body include, in addition to the metal foam 50 , aggregates of metal particles aggregated with gaps between the particles.

[0037] The thickness of the metal foam 50 in the first direction is greater than the thickness of the protective member 40 in the first direction. As mentioned above, since the protective member 40 is less than 1 mm, the metal foam 50 can also be greater than 1 mm. Furthermore, the shape of the metal foam 50 when viewed from the first direction can be a rectangular shape that is substantially the same as the shape of the protective member 40 when viewed from the first direction. Furthermore, the metal foam 50 can be larger than the protective member 40. In this case, the metal foam 50 has a non-opposing portion that does not overlap with the protective member 40 in the first direction. Exhaust gas from the power storage device 20 can pass through the metal foam 50 and exit from this non-opposing portion toward the exhaust port 34. Compared to a metal foam 50 of the same size as the protective member 40, the distance it passes through the metal foam can be increased, making it easier for the metal foam 50 to cool the exhaust gas and capture solids and liquids contained in the exhaust gas.

[0038] like Figure 3 As shown, when an abnormality occurs in the electrical storage device 20, gas and flames are exhausted from the exhaust portion 21. The exhausted gas contains gas and particles from the contents of the electrical storage device 20. The gas exhausted from the electrical storage device 20 strikes the metal foam 50 and diffuses, reducing the shock wave generated by the exhaust. The metal foam 50 captures particles contained in the gas.

[0039] In addition, the gas entering the metal foam 50 is cooled by the metal foam 50 while flowing in the second direction (a direction perpendicular to the first direction and parallel to the protective component 40) inside the metal foam 50, and is cooled by the porous body 35 at the exhaust port 34. The porous body 35 captures particles that are not captured by the metal foam 50, and only the gas is discharged to the outside of the battery module 10.

[0040] In this case, it is preferable that at least a portion of the end surface of the metal foam 50 in the second direction is exposed from the protective member 40. This structure can promote the movement of exhaust gas in the second direction within the metal foam 50. Therefore, when the metal foam 50 is attached to the protective member 40, it is preferable that there is no fixed portion fixed to the protective member 40 on at least one of the multiple lines extending in the second direction. Even if a fixed portion is provided on any line, it is preferable that the position of the fixed portion is staggered in the second direction.

[0041] In recent years, in the storage module 10, as the capacity of the storage device 20 increases, the amount of gas discharged when the storage device 20 is abnormal has tended to increase. As the amount of gas discharged from the storage device 20 increases, the discharge time of the gas containing high-temperature particles becomes longer. As a result, for example, the protective component 40 is prone to high temperature and may be corroded and damaged (opened) by high-temperature particles. As a result, the gas not only directly touches the protective component 40 that directly receives the gas, but also directly touches the porous body 35 of the exhaust port 34. As a result, the porous body 35 of the exhaust port 34 may also melt or be penetrated in the same way, causing the exhaust gas to be released to the outside of the shell 30 while maintaining high temperature and momentum.

[0042] According to the storage battery module 10 of this embodiment, by providing the metal foam 50 on the other side of the first direction of the protective member 40, when the storage battery device 20 discharges gas in an abnormal situation, the metal foam 50 can act as a filter to capture high-temperature particles in the gas and cool the gas, thereby diffusing the impact of the gas and improving reliability.

[0043] More specifically, when the power storage device 20 discharges gas during an abnormality, the gas enters the interior of the metal foam 50, where more high-temperature particles and the like in the gas are captured. Furthermore, as described above, the gas that enters the metal foam 50 is blocked by the protective member 40 and flows around the protective member 40. This lengthens the flow path in the metal foam 50, allowing more high-temperature particles and the like in the gas to be captured within the metal foam 50.

[0044] Furthermore, when the power storage device 20 discharges gas during an abnormality, the gas enters the interior of the metal foam 50, where the high-temperature gas is cooled. Furthermore, as described above, the gas that has entered the metal foam 50 is blocked by the protective member 40 and flows around the protective member 40, extending the flow path in the metal foam 50 and improving the cooling effect of the high-temperature gas in the metal foam 50.

[0045] Furthermore, when the electricity storage device 20 discharges gas in an abnormal state, the gas enters and diffuses into the metal foam 50. This prevents the protective member 40 from being damaged by the shock wave of the gas discharge.

[0046] As described above, when the power storage device 20 discharges gas during an abnormality, the metal foam 50 acts as a filter, capturing high-temperature particles and the like in the gas and cooling the gas, thereby diffusing the impact of the gas. This allows the thickness of the protective member 40 to be reduced compared to conventional power storage modules that only include the protective member 40. Consequently, by reducing the thickness of the protective member 40 and providing the lightweight metal foam 50, the power storage module 10 can be made lighter than conventional power storage modules that only include the protective member 40.

[0047] [Another embodiment]

[0048] use Figure 4 Next, a power storage module 60 as another example of the embodiment will be described. Components identical to those of the power storage module 10 will be described using the same reference numerals, and descriptions of these components will be omitted.

[0049] In the battery module 60, a metal foam 70 is provided at the exhaust port 34 of the housing 30. In this embodiment, the metal foam 70 is sandwiched between the porous bodies 35 provided at the exhaust port 34. However, the present disclosure is not limited to this embodiment; a metal foam 70 may be provided instead of the porous body 35 on one side in the first direction. The metal foam 70 is made of the same material as the metal foam 50 described above. Furthermore, the shape of the metal foam 70, when viewed from the first direction, is preferably substantially the same as that of the exhaust port 34.

[0050] According to the electricity storage module 10 of this embodiment, the metal foam 70 can reliably capture high-temperature particles and the like in the gas that are not captured by the metal foam 50, thereby preventing the high-temperature particles and the like in the gas from being discharged to the outside of the electricity storage module 10. Furthermore, the cooling effect of the gas passing through the exhaust port 34 can be enhanced.

[0051] In addition, the present disclosure will be further described using the following embodiments.

[0052] Structure 1: A storage module comprising a plurality of storage devices and a housing for housing the plurality of storage devices, wherein the storage devices discharge internal gas toward one side in a first direction in the event of an abnormality, a protective member is provided on one side of the storage devices in the first direction within the housing, and a porous body having three-dimensionally extending pores is provided on the other side of the protective member in the first direction.

[0053] Configuration 2: The electricity storage module according to Configuration 1, wherein a thickness of the porous body in the first direction is greater than a thickness of the protection member in the first direction.

[0054] Structure 3: The electricity storage module according to Structure 1 or 2, wherein a shape of the porous body as viewed from the first direction is substantially the same as a shape of the protection member as viewed from the first direction.

[0055] Structure 4: The power storage module according to any one of Structures 1 to 3, wherein the protection member has an aperture ratio smaller than that of the porous body or has no through-holes.

[0056] Structure 5: The power storage module according to any one of Structures 1 to 4, wherein an end surface of the porous body is exposed from the protective member in a second direction perpendicular to the first direction.

[0057] Structure 6: The power storage module according to any one of Structures 1 to 5, wherein the porous body has a portion extending from the protective member in a second direction perpendicular to the first direction.

[0058] Structure 7: A storage module according to any one of Structures 1 to 6, wherein the porous body is a first foam body, the shell has an exhaust port, which connects the internal space of the shell that accommodates the storage device with the outside and is used to discharge gas discharged from the storage device from the internal space to the outside, and a second foam body is provided at the exhaust port.

[0059] In addition, the present disclosure is not limited to the above-described embodiment and its modified examples, and it goes without saying that various changes and improvements can be made within the scope of the matters described in the claims of the present application.

[0060] Description of Reference Numerals

[0061] 10. Energy storage module; 20. Energy storage device; 21. Exhaust portion; 30. Housing; 31. Main body; 32. Cover; 33. Cover; 34. Exhaust port; 35. Porous body; 40. Protective member; 50. Metal foam (porous body or first foam); 60. Energy storage module; 70. Metal foam (second foam).

Claims

1. A power storage module comprising a plurality of power storage devices and a housing for accommodating the plurality of power storage devices, wherein: The power storage device discharges internal gas toward one side in a first direction when an abnormality occurs. A protection member is provided on one side of the power storage device in the first direction inside the housing. A porous body having three-dimensionally extending pores is provided on a surface of the protection member facing the power storage device in the first direction.

2. The power storage module according to claim 1, wherein The thickness of the porous body in the first direction is greater than the thickness of the protection member in the first direction.

3. The power storage module according to claim 1 or 2, wherein: The shape of the porous body when viewed from the first direction is substantially the same as the shape of the protection member when viewed from the first direction.

4. The power storage module according to any one of claims 1 to 3, wherein The protection member has an opening ratio smaller than that of the porous body or has no through-holes.

5. The power storage module according to any one of claims 1 to 4, wherein In a second direction perpendicular to the first direction, an end surface of the porous body is exposed from the protective member.

6. The power storage module according to any one of claims 1 to 5, wherein: The porous body has a portion extending from the protection member in a second direction perpendicular to the first direction.

7. The power storage module according to any one of claims 1 to 6, wherein: The porous body is a first foamed body, The housing has an exhaust port that connects the interior of the housing with the outside and is used to discharge gas exhausted from the power storage device to the outside. A second foam is provided at the exhaust port.

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