JP2017228496A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device having an exterior body, having improved safety.SOLUTION: A power storage device 1 includes an exterior body 10. The exterior body 10 is provided with an exhaust part 50 that forms a passage 54 that communicates the inside and the outside of the exterior body 10. The exhaust part 50 has a moving member 60 that is movable at least in part while maintaining a state in which the exhaust part is disposed so as to close the passage 54 in the passage 54.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power storage device including an exterior body.

  2. Description of the Related Art Conventionally, there are power storage devices that include an exterior body, such as a power storage element that includes a container that stores an electrode body, and a power storage module that includes a housing that stores one or more power storage elements. In such a power storage device, a configuration for releasing gas generated inside the exterior body to the outside is known.

  For example, Patent Document 1 discloses an assembled battery that includes a plurality of unit cells and includes an exhaust duct that extends in the arrangement direction of the unit cells. This exhaust duct is provided with a gas inlet at a position corresponding to the gas discharge valve of each unit cell in the longitudinal direction, and a gas outlet is provided at an end in the longitudinal direction. One end of a connecting pipe is connected to the gas outlet, and a connector is connected to the other end of the connecting pipe. The connector penetrates the lid and projects to the outside of the outer case, and is connected to the downstream flow path.

  In addition, for example, in Patent Document 2, a can having an open end, an electrochemical material having two electrodes provided inside the can, and an electrochemical material leaking from the can by providing the open end of the can. And a dry battery provided with a moisture protection wall provided at the open end of the can to prevent external moisture from reaching the seal. The seal is provided with a relatively thin section that breaks open when the internal cell pressure becomes excessive.

JP 2014-72091 A Japanese translation of PCT publication No. 2002-530811

  As described in Patent Document 1, by providing a duct for connecting the inside and outside of the exterior body to the exterior body, gas generated inside the exterior body (gas released from the unit cell in Patent Document 1) is, for example, a human body. It is possible to guide to a position that does not affect the position. However, the gas flow path formed by the duct can also serve as a moisture ingress path from the outside to the inside of the exterior body. When moisture enters the interior of the exterior body, for example, dew condensation occurs inside the exterior body, and this can be a cause of defects such as a short circuit.

  In view of this, for example, a member such as a seal described in Patent Document 2 may be arranged in the duct so as to be in an open state when the pressure inside the exterior body becomes excessive. However, in this case, for example, due to fluctuations in the pressure difference between the inside and outside of the exterior body caused by fluctuations in the outside air temperature or outside pressure, or due to repetition of such fluctuations, the member breaks at times other than abnormal times. there is a possibility.

  In view of the above-described conventional problems, an object of the present invention is to provide a power storage device that includes an exterior body and that has improved safety.

  In order to achieve the above object, a power storage device according to one embodiment of the present invention is a power storage device including an exterior body, and the exterior body has a passage that communicates the inside and the outside of the exterior body. An exhaust portion is provided, and the exhaust portion includes a moving member that is movable at least partially while maintaining a state of being disposed so as to close the passage in the passage.

  According to this configuration, for example, due to an internal short circuit or the like, there is an abnormality in which a large amount of the electrolyte solution sealed in the outer package or the electrolyte solution sealed in the power storage element accommodated in the outer package is vaporized. When generated, gas generated by vaporization can be guided to the outside of the exterior body through the passage of the exhaust part. Thereby, the raise of the internal pressure of the exterior body at the time of abnormality is suppressed. Moreover, since the moving member is disposed so as to block the passage, inflow of moisture (water droplets, moisture, etc.) through the passage from the outside to the inside of the exterior body is suppressed. Furthermore, at least a part of the moving member is movable. That is, the moving member can operate so as to absorb a pressure difference between the inside and outside of the exterior body, for example, at normal times. For this reason, for example, the passage is not normally opened (destruction of the moving member or the like) due to the repetition of the fluctuation of the pressure difference. Thus, the power storage device according to this aspect is a power storage device with improved safety.

  In the power storage device according to one embodiment of the present invention, the moving member may be a liquid that blocks the passage.

  Thus, by adopting the liquid as the moving member, for example, the moving member can move smoothly in the passage while closing the passage. That is, the pressure difference is efficiently absorbed by the moving member while suppressing the inflow of moisture through the passage from the outside to the inside of the exterior body. Further, by selecting a highly viscous liquid as the moving member, leakage from the exhaust part of the moving member during normal times is suppressed. Moreover, the moisture inflow suppression effect (moisture-proof effect) by a moving member is improved by selecting the liquid containing an oil component as a moving member. Furthermore, by selecting a liquid with low volatility as the moving member, for example, the life of the moving member can be extended.

  In the power storage device according to one embodiment of the present invention, the passage may include a storage portion that stores the moving member with a trap structure.

  According to this configuration, the storage portion is formed by, for example, a portion in which the passage is folded upward from the downward direction (a portion that is raised after being lowered). An inflow suppressing effect can be obtained. In addition, by disposing the moving member in the storage unit, for example, when the power storage device is tilted, the moving member can be prevented from jumping out or leaking out from the exhaust unit.

  In the power storage device according to one embodiment of the present invention, the exhaust unit further includes a storage unit that forms a space in which the moving member can be stored. The storage unit includes the moving member of the passage. It may be connected to the passage at a position between the open position and the external opening of the passage.

  According to this configuration, the accommodating portion connected to the passage is disposed at a position before the outlet (opening portion) on the outer side of the passage as viewed from the moving member. Thereby, for example, the moving member that moves in the passage by the pressure of the gas generated inside the exterior body can be guided to the housing portion, and the gas can be guided to the outside of the exterior body. Therefore, for example, when a large amount of gas is generated inside the exterior body, the possibility that the moving member is discharged to the outside of the exterior body together with the gas is reduced. As a result, for example, the occurrence of problems caused by the moving member coming into contact with a heat source outside the exterior body is suppressed.

  In the power storage device according to one embodiment of the present invention, the passage may include a narrow portion in which an area of a cross section perpendicular to the axial direction of the passage is smaller than other portions.

  According to this configuration, an effect of suppressing the jumping or leakage of the moving member from the exhaust part can be obtained by the narrow part.

  In the power storage device according to one embodiment of the present invention, the narrow portion may be disposed in the vicinity of one of both ends of the passage.

  According to this configuration, since the narrow portion is disposed near the opening on the inner side or the outer side of the exterior body of the passage, the moving member can be narrowed in a relatively wide range in the axial direction of the passage. Can move without hindrance. That is, even when the pressure difference between the inside and outside of the exterior body at a normal time is relatively large, the pressure difference can be absorbed by the movement of the moving member.

  In the power storage device according to one embodiment of the present invention, the exhaust portion may include one or more plate portions that are erected on an inner wall that forms the passage.

  According to this structure, the exhaust part which has a labyrinth structure can be formed by arrange | positioning one or more board parts, for example to the inner wall of a simple straight pipe-shaped member. That is, a passage having a shape that suppresses the inflow of moisture from the outside to the inside of the exterior body and suppresses the jumping out or leakage of the moving member from the exhaust portion can be realized with a relatively simple structure.

  According to the present invention, a power storage device with improved safety can be provided.

It is a perspective view which shows the external appearance of the electrical storage apparatus which concerns on embodiment. It is a disassembled perspective view of the electrical storage apparatus which concerns on embodiment. It is sectional drawing which shows the structure of the exhaust part which concerns on embodiment. It is a figure which shows the state of an exhaust part in case the internal pressure of an exterior body is larger than an external pressure. It is a figure which shows the state of an exhaust part in case the external pressure of an exterior body is larger than an internal pressure. It is a figure which shows the state of the exhaust part at the time of discharge | releasing the gas inside an exterior body outside. It is sectional drawing which shows the structure of the exhaust part which concerns on the modification 1 of embodiment. It is sectional drawing which shows the structure of the exhaust part which concerns on the modification 2 of embodiment. It is sectional drawing which shows the structure of the exhaust part which concerns on the modification 3 of embodiment. It is a perspective view which shows the structure of the channel | path formation part which concerns on the modification 3 of embodiment. It is sectional drawing which shows the structure of the exhaust part formed by arrange | positioning a channel | path formation part on the outer side of an exterior body. It is sectional drawing which shows the structure of the exhaust part formed by the channel | path formation part being fitted by the through-hole of an exterior body.

  Hereinafter, a power storage device according to an embodiment of the present invention will be described with reference to the drawings. Note that each drawing is a diagram for explaining the power storage device according to the embodiment or its modification, and is not necessarily illustrated strictly.

  In addition, each of the embodiments and modifications described below is a specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of constituent elements, assembling methods, assembling orders, and the like shown in the following embodiments and modifications are merely examples, and are not intended to limit the present invention. . Further, among the constituent elements according to the following embodiments and modifications, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

(Embodiment)
First, a configuration outline of the power storage device 1 according to the embodiment will be described with reference to FIGS. 1 and 2.

FIG. 1 is a perspective view showing an external appearance of a power storage device 1 according to the embodiment. FIG. 2 is an exploded perspective view of power storage device 1 according to the embodiment.

  In these figures, the Z-axis direction is shown as the up-down direction, and the Z-axis direction will be described below as the up-down direction. However, depending on the mode of use, the Z-axis direction may not be up-down. That is, the Z-axis direction is not limited to being the vertical direction.

  The power storage device 1 is a device that can charge electricity from the outside and discharge electricity to the outside. For example, the power storage device 1 is a battery module used for power storage use, power supply use, and the like.

  As shown in these drawings, the power storage device 1 includes an exterior body 10. In the present embodiment, as shown in FIG. 2, four power storage elements 100 are accommodated in the exterior body 10. In addition, although other elements, such as a control board which monitors and controls the state of each electrical storage element 100, may be accommodated in the exterior body 10, illustration and description about these other elements are abbreviate | omitted.

  The outer package 10 is a rectangular (box-shaped) container (module case), and holds the contents such as the plurality of power storage elements 100 in a predetermined position and protects them from impacts and the like. The package 10 is formed of an insulating resin such as polycarbonate (PC) or polypropylene (PP).

  Specifically, the exterior body 10 includes a main body 12 that houses the power storage element 100 and a lid body 11 that is disposed so as to close the opening of the main body 12. The peripheral edge of the opening of the main body 12 and the peripheral edge of the lid 11 are joined so that airtightness is maintained by a technique such as thermal welding.

  The exterior body 10 is provided with an exhaust portion 50 that forms a passage that communicates the inside and the exterior of the exterior body 10. An opening 52 is formed on the side surface of the exterior body 10 (in this embodiment, the surface on the negative side in the Y-axis direction of the lid body 11). For example, gas is released from one or more power storage elements 100. In this case, the gas is discharged from the opening 52 of the exhaust unit 50 to the outside of the exterior body 10. Details of the exhaust unit 50 will be described later with reference to FIGS. 3 and 4.

  The lid 11 is a member that forms the upper surface 13 of the exterior body 10, and is provided with a positive external terminal 21 and a negative external terminal 22. The power storage device 1 charges electricity from the outside via the positive electrode external terminal 21 and the negative electrode external terminal 22, and discharges electricity to the outside.

  In the present embodiment, the bus bar including the portion forming the positive external terminal 21 and the bus bar including the portion forming the negative external terminal 22 are integrally provided on the resin lid 11 by insert molding. ing. Thereby, the airtightness in the part which the two external terminals (21, 22) of the cover body 11 exposed is maintained.

  Here, in the present embodiment, the four power storage elements 100 are connected in series by the three bus bars 30 as shown in FIG. Although not shown in FIG. 2, one of the power storage elements 100 at both ends in series connection (the power storage element 100 on the most negative side in the Y-axis direction in FIG. 2) and the positive electrode external terminal 21 are electrically connected. Has been. Furthermore, the other of the power storage elements 100 at both ends (the power storage element 100 on the most positive side in the Y-axis direction in FIG. 2) and the negative electrode external terminal 22 are electrically connected.

  The power storage element 100 is a secondary battery (unit cell) that can charge and discharge electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. . The power storage element 100 includes a flat container 110 and a positive electrode terminal 120 and a negative electrode terminal 130 disposed in the container 110. In addition, the electrical storage element 100 is not limited to a nonaqueous electrolyte secondary battery, A secondary battery other than a nonaqueous electrolyte secondary battery may be sufficient, and a capacitor may be sufficient as it.

  In the electric storage element 100, inside the container 110, there are an electrode body 200, a positive electrode current collector that connects the electrode body 200 and the positive electrode terminal 120, and a negative electrode current collector that connects the electrode body 200 and the negative electrode terminal 130. Has been placed. In addition, a liquid such as an electrolytic solution is sealed inside the container 110. In FIG. 2, the electrode body 200 is conceptually represented by a rectangular parallelepiped drawn with a broken line, and the shape and size of the electrode body 200 are not limited to the shape and size shown in FIG. 2.

  The container 110 is composed of a rectangular container made of metal and having a bottom, and a metal lid plate that closes the opening of the container body. The container 110 has a structure that can seal the inside by housing the electrode body 200 and the like and then welding the lid plate and the container body.

  A gas discharge valve 170 is provided on the surface of the container 110 on which the electrode terminals (120, 130) are arranged. For example, as shown in FIG. 2, the plurality of power storage elements 100 are arranged such that the gas discharge valves 170 are arranged in the arrangement direction (Y-axis direction) of the plurality of power storage elements 100.

  The gas discharge valve 170 is opened when the internal pressure of the container 110 rises, and is provided in each power storage element 100 as a safety mechanism that discharges the gas inside the container 110. Note that not all of the plurality of power storage elements 100 included in the power storage device 1 include the gas discharge valve 170, and it is sufficient that at least one power storage element 100 includes the gas discharge valve 170.

  The electrode body 200 included in the power storage element 100 is, for example, a wound electrode body 200 formed by winding a layered arrangement so that a separator is sandwiched between a positive electrode and a negative electrode. In addition, the electrode body 200 is not limited to a winding type, For example, the electrode body 200 may be a stacked electrode body 200 in which flat plate plates are stacked.

  The positive electrode is an electrode plate in which a positive electrode active material layer is formed on the surface of a long strip-like conductive positive electrode current collector foil made of aluminum or an aluminum alloy. The negative electrode is an electrode plate in which a negative electrode active material layer is formed on the surface of a long strip-like conductive negative electrode current collector foil made of copper or a copper alloy. The separator is a microporous sheet.

  Note that as a material of the positive electrode, the negative electrode, and the separator used in the power storage element 100, known materials can be appropriately used as long as the performance of the power storage element 100 is not impaired. Further, the electrolyte solution (nonaqueous electrolyte) sealed in the container 110 is not particularly limited as long as it does not impair the performance of the power storage device 100, and various types can be selected.

  The positive electrode terminal 120 and the negative electrode terminal 130 lead out the electricity stored in the electrode body 200 accommodated in the container 110 to the external space of the power storage element 100, and also store the electricity in the electrode body 200 in order to store the electricity. It is a metal electrode terminal for introducing electricity into the internal space.

  In this embodiment, each of the positive terminal 120 and the negative terminal 130 is provided with a bolt for connecting to the bus bar, and the positive terminal 120 and the negative terminal 130 and the bus bar are fastened by the bolt and nut. Is done. In addition, each of the positive electrode terminal 120 and the negative electrode terminal 130 and the bus bar may be joined by welding such as laser welding.

  The electrical storage element 100 having the above configuration is disposed adjacent to the partition member 40 in the present embodiment. That is, the exterior body 10 is provided with a partition member 40 that partitions between two adjacent power storage elements 100 among the plurality of power storage elements 100. By this partition member 40, for example, position regulation of the power storage element 100 or electrical insulation between the containers 110 of the power storage element 100 is achieved.

  The partition member 40 is formed of an insulating resin such as PC or PP, but may be formed of any material as long as it is an insulating material. Moreover, the partition member 40 may be provided integrally with the main body 12 of the exterior body 10, or may be manufactured as a separate component from the main body 12 of the exterior body 10 and may be retrofitted to the main body 12.

  Next, the exhaust part 50 provided in the exterior body 10 of the power storage device 1 according to the present embodiment will be described with reference to FIGS.

  FIG. 3 is a cross-sectional view illustrating a configuration of the exhaust unit 50 according to the embodiment. Specifically, FIG. 3 shows a part of a section taken along the line III-III in FIG. 2 (a section in the YZ plane passing through the one-dot chain line). Also, the dotted line in FIG. 3 represents the axis of the passage 54 (virtual line along the fluid traveling direction when the fluid passes through the passage 54).

  As shown in FIGS. 1 to 3, the exterior body 10 is provided with an exhaust portion 50, and the exhaust portion 50 forms a passage 54 that communicates the inside and the exterior of the exterior body 10. Specifically, in the present embodiment, as shown in FIG. 3, a passage forming portion 51 is attached to the inner surface of the lid body 11. The passage forming portion 51 forms a passage 54 that communicates the internal space A and the external space B of the exterior body 10 together with the opening 52 formed in the lid body 11. In FIG. 3 and subsequent figures, an example of the basic shape of the passage 54 is shown, and specifications such as the shape, length, and width of the passage 54 are not limited to the specifications shown in FIG.

  The passage forming portion 51 is a member formed of an insulating resin such as PC or PP, for example, like the exterior body 10, and is fixed to the inner surface of the lid 11 by a technique such as adhesion, welding, or fastening. Yes. In the passage forming portion 51, a plurality of plate portions 56 extending in the vertical direction are disposed inside, so that a passage 54 meandering up and down is formed. That is, the exterior body 10 is provided with an exhaust portion 50 having a labyrinth structure.

  The passage forming part 51 has an opening 53 on the inner space A side, and the passage 54 is formed so as to connect the opening 53 on the inner space A side and the opening 52 on the outer space B side. ing. The shape of the cross section (cross section orthogonal to the axis) of the portion formed by the passage forming portion 51 of the passage 54 is not particularly limited, but is, for example, circular or substantially circular.

  The exhaust part 50 having such a structure includes a moving member 60 that can move at least partially in the passage 54 while maintaining a state of being disposed so as to close the passage 54. Specifically, at least a part of the moving member 60 moves in the passage 54 as the pressure in the internal space A or the external space B increases or decreases (that is, the pressure difference inside and outside the exterior body 10). . More specifically, at least a part of the moving member 60 moves in the passage 54, so that the passage 54 can be in an open state (a state in which fluid can pass).

  In the present embodiment, a liquid that closes the passage 54 is employed as the moving member 60. Specifically, a part of the passage 54 in the axial direction (a part of the passage 54 in the longitudinal direction) is blocked by the moving member 60 that is a liquid. That is, the passage 54 is in a liquid-sealed state at the normal time.

  As the liquid employed as the moving member 60, for example, a liquid having a predetermined viscosity including oil is employed. For example, hydraulic oil that is generally used as a power transmission medium in a hydraulic device is disposed as a moving member 60 in the exhaust unit 50. Examples of such hydraulic oil include flame retardant hydraulic oil such as phosphate ester hydraulic oil. Since such hydraulic oil has low volatility, for example, the life of the moving member 60 can be extended.

  The predetermined viscosity of the moving member 60 is, for example, that the moving member 60 can move in the passage 54 due to a differential pressure inside and outside the exterior body 10 in a normal state, and the power storage device 1 is tilted. In such a case, the viscosity of the moving member 60 is such that the moving member 60 does not flow out of the exhaust part 50 due to its own weight. Further, in determining the predetermined viscosity, a cross-sectional area of a cross section orthogonal to the axis of the passage 54 is also taken into consideration. Alternatively, after the predetermined viscosity is determined, the shaft of the passage 54 satisfies the above condition (the moving member 60 can move in the passage 54 and the moving member 60 does not flow out of the exhaust part 50 due to its own weight). The cross-sectional area of the cross section orthogonal to the cross section may be determined.

  Specifically, power storage device 1 according to the present embodiment can be used as, for example, a battery for starting a motorcycle. Therefore, the viscosity of the liquid that is the moving member 60 and the size and shape of the passage 54 may be determined so that the moving member 60 does not flow out of the exhaust part 50 when the motorcycle falls.

  In addition, since the moving member 60 may come into contact with the gas generated when the electrolytic solution of the electricity storage device 100 is vaporized, it has scientific resistance to, for example, an organic solvent contained in the electrolytic solution. Is preferred.

  Moreover, in this Embodiment, as shown in FIG. 3, the channel | path 54 which the exhaust part 50 has includes the storage part 55 which stores the moving member 60 by a trap structure. That is, the storage portion 55 is formed by a portion where the passage 54 is folded upward from the downward direction (the portion that is raised after being lowered). In a state where the moving member 60 is stored in the storage portion 55, the passage 54 is sealed by the moving member 60. In addition, the shape of the channel | path 54 which comprises the storage part 55 is not limited to the shape shown in FIG. 3, What is necessary is just the shape which can store the moving member 60, such as U shape or V shape. The storage unit 55 has a function of keeping the moving member 60 at a predetermined position in the passage 54 at the normal time. Thereby, for example, leakage from the exhaust part 50 of the moving member 60 at the normal time is suppressed.

  In the exhaust portion 50 configured as described above, the moving member 60 moves in the passage 54 in accordance with the fluctuation of the pressure difference between the inside and outside of the exterior body 10. This will be described with reference to FIGS.

  FIG. 4 is a diagram showing the state of the exhaust part 50 when the internal pressure of the exterior body 10 is larger than the external pressure, and FIG. 5 shows the state of the exhaust part 50 when the external pressure of the exterior body 10 is larger than the internal pressure. FIG.

  For example, when the internal pressure of the exterior body 10 becomes larger than the external pressure due to an increase in the temperature inside the exterior body 10 or a decrease in atmospheric pressure around the power storage device 1, the moving member 60 is The inside of the passage 54 is moved to the outside of the exterior body 10 (in the direction of the opening 52). Note that the rise and fall of the atmospheric pressure around the power storage device 1 occurs due to, for example, a change in weather at the place where the power storage device 1 is disposed, an altitude change during transportation of the power storage device 1, and the like.

  Specifically, as the pressure difference Pd1 inside and outside the exterior body 10 increases (Pd1 = internal pressure−external pressure> 0), the pressure difference Pd1 causes the moving member 60 to move toward the opening 52 on the outside of the exterior body 10. Acting as a pushing (or pulling) force, the movement of the moving member 60 in the passage 54 starts. Thereafter, the moving member 60 moves in the direction of the opening 52, whereby the volume of the internal space A of the exterior body 10 increases by a volume corresponding to the moving distance of the moving member 60 in the passage 54. Thereby, the internal pressure of the exterior body 10 falls, and the internal and external pressures of the exterior body 10 are substantially balanced. As a result, the moving member 60 stops at, for example, the position shown in FIG. Even in this case, the state in which the moving member 60 blocks the passage 54 is maintained.

  For example, when the external pressure of the exterior body 10 becomes larger than the internal pressure due to, for example, an increase in temperature or pressure around the power storage device 1, the moving member 60 moves inside the passage 54 in the exterior body 10. Move to the inside (in the direction of the opening 53).

  Specifically, as the pressure difference Pd2 inside and outside the exterior body 10 increases (Pd2 = external pressure−internal pressure> 0), the pressure difference Pd2 causes the moving member 60 to move toward the opening 53 on the inside of the exterior body 10. Acting as a pushing (or pulling) force, the movement of the moving member 60 in the passage 54 starts. Thereafter, the moving member 60 moves in the direction of the opening 53, whereby the volume of the internal space A of the exterior body 10 decreases by a volume corresponding to the moving distance of the moving member 60 in the passage 54. Thereby, the internal pressure of the exterior body 10 increases, and the pressure inside and outside the exterior body 10 is substantially balanced. As a result, the moving member 60 stops at the position shown in FIG. 5, for example. Even in this case, the state in which the moving member 60 blocks the passage 54 is maintained.

  4 and 5, the entire moving member 60 is moving, but only a part of the moving member 60 moves in the axial direction of the passage 54, that is, the axial direction of the passage 54 of the moving member 60. It is possible to absorb the pressure difference between the inside and outside of the exterior body 10 by extending and contracting the length of the outer casing 10. That is, in the present embodiment, the moving member 60 is a liquid such as hydraulic oil. Therefore, even if the moving member 60 does not move as a whole, a part of the moving member 60 can move (length can be expanded and contracted) while maintaining the state where the passage 54 is closed.

  As described above, when the pressure difference between the inside and outside of the exterior body 10 fluctuates due to a change in the environment around the power storage device 1 or heat generation when the power storage device 1 is used, the pressure inside and outside the exterior body 10 is changed. The moving member 60 moves in the passage 54 so as to keep the passage 54 closed. Thereby, for example, the exterior body 10 including the exhaust part 50 is unlikely to have a problem such as destruction or deterioration due to fluctuations in the pressure difference between the inside and outside of the exterior body 10 or repeated fluctuations.

  Further, when the gas discharge valve 170 of one or more power storage elements 100 accommodated in the exterior body 10 is opened and the gas is exhausted for some reason, the internal pressure of the exterior body 10 rapidly increases, A state in which the increase of the internal pressure cannot be absorbed only by the movement of the moving member 60 in the passage 54 occurs. In this case, the gas inside the exterior body 10 is released to the outside of the exterior body 10 through the exhaust part 50.

  FIG. 6 is a diagram illustrating a state of the exhaust unit 50 when the gas inside the exterior body 10 is released to the outside.

  In the power storage device 1, when a large amount of gas is generated inside the exterior body 10 due to, for example, opening of the gas discharge valve 170 of one or more power storage elements 100, the moving member 60 in the passage 54 becomes the internal pressure of the exterior body 10. It is pushed and moves in the direction of the opening 52 on the outside of the exterior body 10.

  Here, the exhaust part 50 according to the present embodiment has a housing part 57 that forms a space in which the moving member 60 can be housed. The accommodating portion 57 is connected to the passage 54 at a position between the storage portion 55 and the opening portion 52. Therefore, the moving member 60 that has moved toward the opening 52 is directed toward the accommodating portion 57 located below the opening 52 as shown in FIG. 6 before reaching the opening 52. As a result, the moving member 60 is accommodated in the accommodating portion 57. Further, when the moving member 60 escapes to the accommodating portion 57 (disengages from the passage 54), the passage 54 is opened, and as a result, the gas inside the exterior body 10 is released from the opening 52 to the outside of the exterior body 10. Is done. Thereby, the rise in the internal pressure of the exterior body 10 is suppressed, and for example, the possibility of destruction of the exterior body 10 due to an excessive internal pressure of the exterior body 10 is reduced.

  As described above, power storage device 1 according to the present embodiment includes exterior body 10. The exterior body 10 is provided with an exhaust portion 50 that forms a passage 54 that communicates the interior and exterior of the exterior body 10. The exhaust unit 50 includes a moving member 60 that can move at least partially in the passage 54 while maintaining a state of being disposed so as to close the passage 54.

  According to this configuration, for example, when an abnormality occurs such that the gas is discharged from the gas discharge valve 170 of the power storage element 100, the gas is guided to the outside of the exterior body 10 through the passage 54 of the exhaust unit 50. be able to. Thereby, the raise of the internal pressure of the exterior body 10 at the time of abnormality is suppressed. Further, since the moving member 60 is disposed so as to block the passage 54, the inflow of moisture (water droplets, moisture, etc.) from the outside to the inside of the exterior body 10 through the passage 54 is suppressed. Furthermore, at least a part of the moving member 60 is movable. That is, the moving member 60 can operate so as to absorb, for example, a pressure difference between the inside and outside of the exterior body 10 at a normal time. Therefore, for example, it is difficult for a component such as the moving member 60 to be broken or broken due to repeated fluctuations in the pressure difference. Thereby, for example, due to environmental changes during normal times, the possibility of the passage 54 being in an open state is reduced. Thus, power storage device 1 according to the present embodiment is power storage device 1 with improved safety.

  In the present embodiment, the moving member 60 is a liquid that blocks the passage 54. By employing a liquid as the moving member 60, for example, the moving member 60 can move smoothly in the passage 54 while closing the passage 54. In other words, the pressure difference between the inside and outside of the exterior body 10 is efficiently absorbed by the moving member 60 while suppressing the inflow of moisture into the exterior body 10 through the passage 54. Further, by selecting a highly viscous liquid as the moving member 60, leakage from the exhaust part 50 of the moving member 60 during normal operation is suppressed. Further, by selecting a liquid containing oil as the moving member 60, the moisture inflow suppressing effect (moisture-proofing effect) by the moving member 60 is improved. Furthermore, by selecting a low-volatile liquid as the moving member 60, for example, the life of the moving member 60 can be extended.

  Moreover, in this Embodiment, the channel | path 54 contains the storage part 55 which stores the moving member 60 by a trap structure. That is, the reservoir 55 is formed by, for example, a portion where the passage 54 is folded upward from the downward direction, so that the effect of suppressing the inflow of moisture into the exterior body 10 by the shape of the passage 54 itself can be obtained. Further, by disposing the moving member 60 in the storage unit 55, for example, jumping out or leakage of the moving member 60 from the exhaust unit 50 when the power storage device 1 is tilted can be suppressed.

  Further, the exhaust part 50 according to the present embodiment further includes a storage part 57 that forms a space in which the moving member 60 can be stored. The accommodating portion 57 is connected to the passage 54 at a position between the position where the moving member 60 of the passage 54 is disposed (the storage portion 55 in this embodiment) and the opening 52 on the outside of the passage 54. Yes.

  That is, the accommodating portion 57 connected to the passage 54 is disposed at a position in front of the outlet (opening portion 52) on the outside of the passage 54 when viewed from the moving member 60. Thereby, for example, the moving member 60 that moves in the passage 54 by the pressure of the gas generated inside the exterior body 10 can be guided to the housing portion 57, and the gas can be guided outside the exterior body 10. Therefore, for example, when a large amount of gas is generated inside the exterior body 10, the possibility that the moving member 60 is discharged to the outside of the exterior body 10 together with the gas is reduced. As a result, for example, the occurrence of problems caused by the moving member 60 coming into contact with a heat source outside the exterior body 10 is suppressed.

  Here, the power storage device 1 may include an exhaust unit having a configuration different from that of the exhaust unit 50 illustrated in FIGS. 3 to 6. Therefore, in the following, a modified example related to the exhaust unit 50 according to the embodiment will be described focusing on differences from the above embodiment.

(Modification 1)
FIG. 7 is a cross-sectional view illustrating a configuration of an exhaust unit 50a according to the first modification of the embodiment. As shown in FIG. 7, the exterior body 10 is provided with an exhaust part 50a. The exhaust part 50 a is configured by attaching a passage forming part 51 a to the inner surface of the lid body 11, and has a passage 54 that communicates the inside and the outside of the exterior body 10. In this structure, the exhaust part 50a according to this modification is common to the exhaust part 50 according to the above embodiment.

  The passage 54 included in the exhaust portion 50a according to the present modification includes a narrow portion 59 in which the cross-sectional area perpendicular to the axial direction of the passage 54 is smaller than that of the other portions. That is, the narrow portion 59 is provided as a component that hinders the movement of the object in the passage 54.

  Thereby, for example, an effect of suppressing jumping out or leakage from the exhaust part 50a of the moving member 60 is obtained. More specifically, in the present modification, the narrow portion 59 is disposed in the vicinity of the opening 53 of the passage 54. Thereby, the jumping out or leakage of the moving member 60 into the exterior body 10 is suppressed.

  Note that the narrow portion 59 may be disposed in the vicinity of the opening 52 of the passage 54. That is, since the narrow portion 59 is disposed in the vicinity of either one of both ends of the passage 54, the moving member 60 is inhibited by the narrow portion 59 in a relatively wide range in the axial direction of the passage 54. You can move without That is, even when the pressure difference between the inside and outside of the exterior body 10 in a normal state is relatively large, the pressure difference can be absorbed by the movement of the moving member 60, and the movement by the narrow portion 59. The effect of suppressing the protrusion or leakage of the member 60 is obtained.

(Modification 2)
FIG. 8 is a cross-sectional view illustrating a configuration of an exhaust unit 50b according to the second modification of the embodiment. As shown in FIG. 8, the exterior body 10 is provided with an exhaust portion 50 b, and the exhaust portion 50 b is configured by attaching a passage forming portion 51 b to the inner surface of the lid body 11. Further, the exhaust part 50 b has a passage 54 that communicates the inside and the outside of the exterior body 10, and a housing part 57 is connected near the opening 52 of the passage 54. In this structure, the exhaust part 50b according to this modification is common to the exhaust part 50 according to the above embodiment. The exhaust part 50b according to the present modification is characterized in that the accommodating part 57a is disposed on the inner side of the exterior body 10.

  That is, the exhaust part 50b according to the present modification has a housing part 57a that forms a space in which the moving member 60 can be housed, and the housing part 57a is located at a position where the moving member 60 is disposed in the passage 54 (this modified example). In the position between the storage portion 55) and the opening 53 on the inner side of the passage 54, the passage 54 is connected.

  Thereby, for example, when the pressure difference Pd2 between the inside and outside of the exterior body 10 (Pd2 = external pressure−internal pressure> 0) becomes extremely large, the exterior body of the travel member 60 is released by letting the travel member 60 escape to the accommodating portion 57a. Leakage into the interior of 10 is suppressed.

  Thereby, for example, the occurrence of problems such as a short circuit due to the moving member 60 being a liquid having a predetermined viscosity coming into contact with the conductive member inside the exterior body 10 is suppressed.

(Modification 3)
FIG. 9 is a cross-sectional view illustrating a configuration of an exhaust unit 150 according to Modification 3 of the embodiment. FIG. 10 is a perspective view showing a configuration of a passage forming portion 151 according to Modification 3 of the embodiment. In addition, in FIG. 10, the structure inside the channel | path formation part 151 is represented by the broken line, and the moving member 60 is represented by the dot.

  As shown in FIG. 9, the exterior body 10 is provided with an exhaust portion 150, and the exhaust portion 150 is configured by attaching a passage forming portion 151 to the inner surface of the lid body 11. Further, the exhaust part 150 has a passage 154 that communicates the inside and the outside of the exterior body 10. The passage 154 has a storage portion 155 that stores the moving member 60 by a trap structure.

  The exhaust unit 150 has the above-described configuration, so that, for example, the gas exhausted from the gas exhaust valve 170 of the power storage element 100 is externally disposed through the passage 154 of the exhaust unit 150, as in the exhaust unit 50 according to the above-described embodiment. It can be guided outside the body 10. Further, since the moving member 60 can move so as to absorb the pressure difference between the inside and outside of the exterior body 10, for example, the moving member 60 and the like are broken or broken due to repeated fluctuation of the pressure difference. It is hard to happen.

  Here, in the exhaust portion 150 according to the present modification, a plurality of plate portions 156 erected on the inner wall 158 forming the passage 154 between the outer opening portion 152 and the inner opening portion 153 are provided. Have. Specifically, in the cross section shown in FIG. 9, the passage forming portion 151 includes two plate portions 156 erected on the lower inner wall 158 and three plate portions 156 erected on the upper inner wall 158. Thus, a passage 154 having more folded portions than the passage 54 according to the above embodiment is formed. That is, in the exhaust part 150, a passage 154 having five turning points is formed by the five plate parts 156 arranged in a posture intersecting with a straight line connecting the opening part 152 and the opening part 153.

  Thus, the channel | path formation part 151 is the structure where the some board part 156 was arrange | positioned in the inner wall 158 of a straight pipe-shaped member. In other words, the passage 154 is formed with a relatively simple structure that suppresses the inflow of moisture from the outside to the inside of the exterior body 10 and also prevents the moving member 60 from jumping out or leaking from the exhaust portion 150. Has been.

  In the exhaust unit 150 according to this modification, for example, when gas is discharged from the gas discharge valve 170 of the power storage element 100 inside the exterior body 10, the moving member 60 is discharged to the outside of the exterior body 10 together with the gas. Is done. However, even in this case, the possibility of the moving member 60 coming into contact with an element outside the exterior body 10 is reduced by, for example, arranging a container that receives the travel member 60 discharged outside the exterior body 10. Can be made.

  In the present modification, the exhaust unit 150 includes the five plate portions 156. However, the exhaust unit 150 may include at least one plate unit 156. For example, in the case where there is one plate portion 156 erected downward from the inner wall 158 on the upper side of the passage forming portion 151, the passage 154 having only one folding portion in the vertical direction is formed. In this case, the passage 154 can be liquid-sealed by the moving member 60 by accommodating the moving member 60 that is, for example, a liquid having a predetermined viscosity in the passage 154.

  Further, in FIG. 9, the exhaust part 150 is formed so as to be entirely inside the exterior body 10, but the exhaust part 150 is formed so that part or all of the exhaust part 150 protrudes from the exterior body 10. Also good.

  FIG. 11 is a cross-sectional view showing a configuration of the exhaust part 150 formed by arranging the passage forming part 151 outside the exterior body 10, and FIG. 12 is a through-hole of the exterior body 10 in the passage forming part 151. It is sectional drawing which shows the structure of the exhaust part 150 formed by being fitted by 10a.

  In the exhaust part 150 shown in FIG. 11, the passage forming part 151 is fixed to the side surface of the lid 11, and the opening 153 inside the exterior body 10 of the passage 154 is formed by the hole formed in the lid 11. Has been. Even when the exhaust part 150 is configured in this way, the functions as the exhaust part 150 such as the above-described function of suppressing the inflow of moisture and the like by the moving member 60 are not lost. Moreover, since the exhaust part 150 is provided in the exterior body 10 without consuming the internal space A of the exterior body 10, it is possible to use the internal space A of the exterior body 10 more efficiently, for example, to increase the storage capacity. it can. Further, for example, the straight tubular passage forming portion 151 can be used as a connection portion (connector) with a pipe for guiding the gas discharged from the exhaust portion 150 to a predetermined position.

  The exhaust part 150 shown in FIG. 12 is configured by fitting a passage forming part 151 into a through hole 10 a provided on the side wall of the lid 11. In addition, an opening 152 on the outer side of the exterior body 10 and an opening 153 on the inner side of the exterior body 10 are formed by holes at both ends of the passage forming portion 151. Even when the exhaust unit 150 is configured in this way, the functions as the exhaust unit 150 such as the function of suppressing the inflow of moisture and the like by the moving member 60 are not lost. Further, a part of the exhaust unit 150 is disposed inside the exterior body 10 and a part is disposed outside the exterior body 10. Therefore, for example, the passage forming portion 151 exposed to the outside can be used as a connector with an external pipe while suppressing consumption of the internal space A by the exhaust portion 150.

  In addition, it is applied also to said exhaust part 50, 50a, and 50b that the one part or all part of the exhaust part 150 may be protruded and provided from the exterior body 10. FIG.

(Other embodiments)
Heretofore, the power storage device according to the present invention has been described based on the embodiment and the modifications thereof. However, the present invention is not limited to the above-described embodiment and its modifications. As long as it does not deviate from the gist of the present invention, various modifications conceived by those skilled in the art may be applied to the above-described embodiment or its modifications, or a form constructed by combining a plurality of the constituent elements described above. Included within the scope of the invention.

  For example, in the above-described embodiment, the passage 54 of the exhaust unit 50 has a bent shape in the YZ plane in the drawings such as FIG. 3, but the exhaust unit 50 has a three-dimensional passage 54. It may be. For example, the passage 54 may be bent in the YZ plane and may be bent in the XY plane. That is, the shape of the passage 54 may be more complicated. Thereby, for example, the effect of suppressing the inflow of moisture through the passage 54 from the outside to the inside of the exterior body 10 is increased. Moreover, since the full length of the channel | path 54 can be made longer, for example, the movable range of the moving member 60 in the normal time is expanded. As a result, even when the pressure difference between the inside and outside of the exterior body 10 at a normal time is relatively large, the pressure difference can be absorbed by the movement of the moving member 60.

  Further, for example, in the above embodiment, the exhaust part 50 is provided in the exterior body 10 that houses one or more power storage elements 100 therein, but the exhaust part 50 may be provided in a container of the power storage element. Good. That is, the exhaust part 50, 50a, 50b, or 150 may be provided in a container that is an exterior body that covers the electrode body, the electrolytic solution, and the like in the power storage element. That is, the “power storage device including an exterior body provided with an exhaust section such as the exhaust section 50” can also be realized as a power storage element including a container as the exterior body.

  In this case, in normal times, the exhaust part is in a state of maintaining airtightness in the container, and when an abnormality occurs such that the evaporation of the electrolyte proceeds rapidly, the gas generated by the vaporization is discharged to the exhaust part. It can be discharged to the outside of the electricity storage element via That is, in the electricity storage element, the exhaust part can exhibit the same effect as the gas discharge valve, and problems such as destruction due to fluctuations in the internal and external pressures of the container of the electricity storage element hardly occur.

  In addition, the moving member 60 included in the exhaust unit 50 or the like is a liquid having a predetermined viscosity. However, the moving member of the exhaust part may be solid or powder. Moreover, the moving member 60 may be formed of a combination of at least two of liquid, solid, and powder.

  For example, when the cross-sectional shape of the passage included in the exhaust portion is a circle, the moving member is a sphere that can be disposed so as to close the passage, and has a size that can move in the passage. May be adopted. In this case, for example, unlike the case where the moving member is a liquid, it is not necessary to consider that the moving member volatilizes.

  Further, when the exhaust part releases the gas inside the outer package 10 to the outside, the entire moving member does not need to move. For example, the passage may be opened by contracting (partly moving) a moving member that closes the passage that connects the inside and the outside of the exterior body 10. In other words, for example, the exhaust part absorbs the pressure difference between the inside and outside of the exterior body 10 by expansion and contraction of the moving member having elasticity, and, at the time of abnormality, the exhaust member contracts, A path (passage) for releasing the internal gas to the outside may be formed.

  Further, for example, when the moving member 60 moves into the accommodating portion 57 (see FIG. 3) by discharging the gas through the exhaust portion 50, for example, the moving member is moved from the accommodating portion 57 by a tool such as a dropper. 60 may be sucked out once and injected into the reservoir 55 (see FIG. 3). Thereby, the exterior body 10 which has escaped destruction due to the gas being discharged from the exhaust part 50 can be reused.

  The present invention can be applied to a power storage element or a power storage device including a plurality of power storage elements.

DESCRIPTION OF SYMBOLS 1 Power storage device 10 Exterior body 10a Through-hole 11 Lid body 12 Main body 13 Upper surface 21 Positive electrode external terminal 22 Negative electrode external terminal 30 Bus bar 40 Partition member 50, 50a, 50b, 150 Exhaust part 51, 51a, 51b, 151 Passage formation part 52, 53, 152, 153 Opening 54, 154 Passage 55, 155 Reserving part 56, 156 Plate part 57, 57a Housing part 59 Narrow part 60 Moving member 100 Power storage element 110 Container 120 Positive electrode terminal 130 Negative electrode terminal 158 Inner wall 170 Gas exhaust valve 200 electrode body

Claims (7)

A power storage device including an exterior body,
The exterior body is provided with an exhaust portion that forms a passage that communicates the interior and exterior of the exterior body,
The exhaust unit includes a moving member in which at least a part of the exhaust unit is movable while maintaining a state where the exhaust unit is disposed so as to close the passage in the passage. The power storage device according to claim 1, wherein the moving member is a liquid that blocks the passage. The power storage device according to claim 1, wherein the passage includes a storage unit that stores the moving member by a trap structure. The exhaust part further includes a storage part that forms a space in which the moving member can be stored.
The said accommodating part is connected with the said channel | path in the position between the position where the said moving member of the said channel | path is arrange | positioned, and the opening part of the said exterior side of the said channel | path. The power storage device described in 1. The power storage device according to claim 1, wherein the passage includes a narrow portion in which an area of a cross section perpendicular to the axial direction of the passage is smaller than other portions. The power storage device according to claim 5, wherein the narrow portion is disposed in the vicinity of one of both ends of the passage. The power storage device according to any one of claims 1 to 6, wherein the exhaust unit includes one or more plate units provided on an inner wall that forms the passage.

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