JP6926712B2 - Power storage device - Google Patents

Description

The present invention relates to a power storage device including a power storage element having a discharge unit capable of discharging internal gas.

In a power storage device including one or more power storage elements, there is known a configuration for discharging exhaust gas from a gas discharge valve or the like included in each power storage element to the outside.

For example, in the battery pack disclosed in Patent Document 1, one exhaust gas passage to which the gas outlet of the cell case housed in each battery module is connected is formed under the battery module group, and further. The cooling passage is arranged so as to surround the exhaust gas passage. In this configuration, even if the gas discharged to the exhaust gas passage enters the cooling passage, the gas does not leak into the vehicle interior because the check valve is provided at the cooling air inlet, and the cooling air outlet is provided together with the cooling air. It can be guided to the outside of the passenger compartment through.

Japanese Unexamined Patent Publication No. 2006-185894

By arranging, for example, a tubular or box-shaped member at a position corresponding to the gas discharge valve of a plurality of power storage elements as in the above-mentioned conventional technique, the gas discharged from each power storage element is guided to a predetermined place. It is possible. However, when each of the plurality of power storage elements is in a state of discharging gas, it may expand due to an increase in the internal pressure, and as a result, a deviation from the normal position may occur. When such a situation occurs, the inventors of the present application may have a problem that, for example, in a power storage device including a plurality of power storage elements, gas from each power storage element is discharged to the outside by an unexpected route. I found.

The present invention has been made by the inventors of the present application paying new attention to the above problems, and is a power storage device including a power storage element having a discharge unit capable of discharging internal gas, and has improved safety. It is an object of the present invention to provide a power storage device.

In order to achieve the above object, the power storage device according to one aspect of the present invention includes a power storage element having a discharge surface provided with a discharge portion capable of discharging internal gas, and an exhaust path at a position facing the discharge portion. The path forming member comprises a side wall portion of the power storage element that abuts on a side surface connected to the peripheral edge of the exhaust surface.

According to this configuration, since the side wall portion of the path forming member is arranged so as to abut on the side surface of the power storage element, the relative positional deviation between the exhaust path and the discharge part of the power storage element is suppressed. Further, for example, the side wall portion suppresses the swelling of the power storage element. That is, the power storage device according to this embodiment mechanically suppresses the deviation of the gas exhaust path caused by the swelling while suppressing the swelling of the power storage element that occurs when the power storage element is in a state of discharging gas. It has a structure. Therefore, a power storage device with improved safety is realized.

Further, the power storage device according to one aspect of the present invention includes a plurality of the power storage elements arranged side by side in the first direction, and each of the plurality of the power storage elements accommodates an electrode body and the electrode body. The container is arranged so that the long side surface of the container faces the first direction and the short side surface of the container faces the second direction orthogonal to the first direction. It is assumed that the side wall portion faces the long side surface and the short side surface of the outermost power storage element among the plurality of the power storage elements, and is continuously formed from the long side surface to the short side surface. May be good.

According to this configuration, it is possible to prevent the exhaust path from being displaced from the position facing the discharge portion of the plurality of power storage elements. More specifically, the side wall portion of the path forming member abuts on the short side surface and the long side surface of the outermost power storage element, thereby restricting the movement of the path forming member in the first direction and the second direction. , The effect of suppressing the displacement of the exhaust path is improved. Further, for example, a power storage device including a number of power storage elements corresponding to a required output voltage or a power storage amount, and a power storage device with improved safety is realized.

Further, in the power storage device according to one aspect of the present invention, the path forming member is adhered between the path forming member and the discharge surface of the power storage element and arranged along the exhaust path. It may be fixed to the discharge surface by a material.

According to this configuration, the presence of the adhesive between the power storage element and the path forming member further suppresses the deviation of the exhaust path from the regular position. Further, since the adhesive material extends along the exhaust path, the airtightness of the exhaust path can be improved more reliably. As a result, for example, the possibility of gas leaking from an unexpected position in the middle of the exhaust path is reduced.

Further, the power storage device according to one aspect of the present invention further includes an exterior body for accommodating the power storage element, and the exterior body covers at least a part of the outer surface of the side wall portion of the path forming member. It may be fixed to the path forming member.

According to this configuration, the position of the path forming member with respect to the power storage element is also regulated by the exterior body. Therefore, for example, suppression of deviation from the regular position of the exhaust path is more ensured. Further, the exterior body functions as a member that suppresses the swelling of the power storage element via the side wall portion. Therefore, it is possible to obtain a power storage device with improved safety.

According to the present invention, it is possible to provide a power storage device including a power storage element having a discharge unit capable of discharging internal gas and having improved safety.

FIG. 1 is a perspective view showing the appearance of the power storage device according to the embodiment. FIG. 2 is an exploded perspective view showing each component when the power storage device according to the embodiment is disassembled. FIG. 3 is a perspective view showing the configuration of the inner lid according to the embodiment. FIG. 4 is a plan view showing an arrangement region of the adhesive material on the side of the plurality of power storage elements according to the embodiment. FIG. 5 is a perspective view showing the positional relationship between the inner lid and the plurality of power storage elements according to the embodiment. FIG. 6 is a cross-sectional view of the power storage device according to the embodiment. FIG. 7 is a perspective view showing the configuration of an inner lid provided with a plurality of convex portions on the side wall portion.

Hereinafter, a power storage device according to an embodiment of the present invention and a modified example thereof will be described with reference to the drawings. The embodiments and modifications thereof described below are all comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement positions of components, connection forms, etc. shown in the following embodiments and modifications thereof are examples, and are not intended to limit the present invention. Further, among the components in the following embodiments and modifications thereof, the components not described in the independent claims indicating the highest level concept are described as arbitrary components. Further, in each figure, the dimensions and the like are not exactly shown.

Further, in the following description and drawings, the arrangement direction of the power storage elements, the direction opposite to the long side surface of the container of the power storage element, or the thickness direction of the container is defined as the Y-axis direction. Further, the alignment direction of the electrode terminals in one power storage element or the opposite direction of the short side surface of the container of the power storage element is defined as the X-axis direction. Further, the direction in which the exterior body of the power storage device, the inner lid, and the outer lid are arranged, the direction in which the power storage element, the bus bar (connecting member), and the substrate are arranged, the direction in which the container body and the lid of the power storage element are arranged, or the vertical direction. Is defined as the Z-axis direction. These X-axis directions, Y-axis directions, and Z-axis directions are directions that intersect each other (hereinafter, orthogonal to each other in the embodiment). Depending on the mode of use, the Z-axis direction may not be the vertical direction, but for convenience of explanation, the Z-axis direction will be described below as the vertical direction. Further, in the following description, for example, the plus side in the X-axis direction indicates the arrow direction side of the X-axis, and the minus side in the X-axis direction indicates the side opposite to the plus side in the X-axis direction. The same applies to the Y-axis direction and the Z-axis direction.

(Embodiment)
[1. General description of power storage device 1]
First, with reference to FIGS. 1 and 2, a general description of the power storage device 1 according to the present embodiment will be given. FIG. 1 is a perspective view showing the appearance of the power storage device 1 according to the embodiment. FIG. 2 is an exploded perspective view showing each component when the power storage device 1 according to the embodiment is disassembled.

The power storage device 1 is a device capable of charging electricity from the outside and discharging electricity to the outside. For example, the power storage device 1 is a battery module used for power storage or power supply. Specifically, the power storage device 1 includes, for example, automobiles such as electric vehicles (EV), hybrid electric vehicles (HEV) or plug-in hybrid electric vehicles (PHEV), motorcycles, watercraft, snowmobiles, agricultural machinery, and construction. It is used as a battery for driving a moving body such as a machine or for starting an engine.

As shown in FIGS. 1 and 2, the power storage device 1 includes an exterior body 10 composed of an outer lid 11 and an exterior body body 12, a plurality of power storage elements 20, connecting members 30, and an inner lid 40 housed in the exterior body 10. And a substrate 50.

The exterior body 10 is a rectangular (box-shaped) container (module case) that constitutes the housing of the power storage device 1. That is, the exterior body 10 holds the plurality of power storage elements 20, the connecting member 30, the inner lid 40, the substrate 50, and the like at predetermined positions and protects them from impacts and the like.

Specifically, the exterior body 10 has an outer lid 11 constituting the lid body of the exterior body 10 and an exterior body main body 12 constituting the main body of the exterior body 10, and in the present embodiment, the outer body 10 has an outer lid 11. The inner lid 40 is arranged between the lid 11 and the exterior body main body 12.

The outer lid 11 is a flat rectangular member that closes the opening of the outer body body 12, and has an external terminal 13 on the positive electrode side and an external terminal 17 on the negative electrode side. The external terminals 13 and 17 are electrically connected to the power storage element 20, and the power storage device 1 charges electricity from the outside and discharges electricity to the outside through the external terminals 13 and 17. The exterior body body 12 is a bottomed rectangular tubular housing (housing) having an opening, and accommodates a power storage element 20 and the like.

The external terminals 13 and 17 are formed of, for example, a conductive member made of metal such as aluminum or an aluminum alloy. The other parts of the exterior body 10 are made of an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), polybutylene terephthalate (PBT), or ABS resin. Has been done. As a result, the exterior body 10 prevents the power storage element 20 and the like from coming into contact with an external metal member or the like.

The power storage element 20 is a secondary battery (cell battery) capable of charging electricity and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. .. The power storage element 20 has a flat rectangular parallelepiped shape (square shape), and in the present embodiment, four power storage elements 20 are arranged in the Y-axis direction. The shape of the power storage element 20 and the number of power storage elements 20 arranged are not limited. Further, the power storage element 20 is not limited to the non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery, a capacitor, and further charged by the user. It may be a primary battery that can use the stored electricity without using the above.

Specifically, the power storage element 20 includes a metal container 21 that houses an electrode body (also referred to as a power storage element or a power generation element) 25, and a pair of electrode terminals 22 and a pair of electrode terminals 22 are provided on the lid plate of the container 21. A discharge unit 27 arranged between the electrode terminals 22 is provided. That is, in the power storage element 20, the discharge surface 23, which is the surface on which the discharge portion 27 is provided, is formed by the upper surface of the lid plate of the container 21. The discharge unit 27 is, for example, a portion called a gas discharge valve, which is opened when the internal pressure rises due to vaporization of the electrolytic solution in the container 21, and is used as a safety mechanism for discharging the gas inside the container 21. It is provided in the element 20.

Further, two short side surfaces 24b and two long side surfaces 24a are connected to the peripheral edge of the discharge surface 23 of the container 21, and the container 21 has a square shape as a whole as described above. It can be expressed that the long side surface 24a is the side surface having the largest area in the container 21, and the short side surface 24b is the side surface having a smaller area than the long side surface 24a.

In the present embodiment, each of the plurality of power storage elements 20 is arranged so that the long side surface 24a of the container 21 faces the Y-axis direction and the short side surface 24b of the container 21 faces the X-axis direction. The Y-axis direction is an example of the first direction, and the X-axis direction is an example of the second direction. Further, the plurality of power storage elements 20 are arranged so that the electrode terminals 22 adjacent to each other in the arrangement direction (Y-axis direction) are opposite to each other.

In addition to the electrode body 25, a current collector (positive electrode current collector and negative electrode current collector) and the like are arranged inside the container 21, and an electrolytic solution (non-aqueous electrolyte) and the like are sealed therein. , Detailed description will be omitted.

The connecting member 30 is a rectangular plate-shaped member that electrically connects the electrode terminals 22 of the adjacent power storage elements 20 in a state of being arranged on the inner lid 40. The connecting member 30 is formed of, for example, a conductive member made of metal such as copper, a copper alloy, aluminum, or an aluminum alloy. The connecting member 30 and the electrode terminal 22 are joined by welding such as ultrasonic welding.

In this embodiment, three connecting members 30 are provided. Four power storage elements 20 are connected in series by these three connecting members 30. Further, of the electrode terminals 22 of the four power storage elements 20 connected in series, the positive electrode terminal, which is one of the two electrode terminals 22 to which the connecting member 30 is not connected, is an external terminal 13 via a bus bar (not shown). Is connected to. Further, the negative electrode terminal, which is the other of the two electrode terminals 22, is connected to the external terminal 17 via a bus bar (not shown). As a result, a state in which the four power storage elements 20, the three connecting members 30, and the bus bar are electrically connected in series is formed between the external terminals 13 and the external terminals 17 at both ends. The substrate 50 is connected in series between the four power storage elements 20 and the external terminal 13, for example.

In the present embodiment, the inner lid 40 is an electrical device that holds the substrate 50, the power storage element 20, the connecting member 30, wirings, etc. (not shown) in a state of being arranged above the plurality of power storage elements 20. Functions as a product tray. The inner lid 40 also functions as a member that regulates the upward movement of the plurality of power storage elements 20. Examples of the material of the inner lid 40 include insulating materials such as PC, PP, PE, PPS, PBT, and ABS resin.

In the present embodiment, the inner lid 40 also functions as a path forming member for forming an exhaust path. Specifically, the inner lid 40 has an exhaust path portion 41 that forms a space extending along the arrangement direction of the plurality of power storage elements 20 at a position facing the discharge units 27 of the plurality of power storage elements 20. doing. As shown in FIGS. 1 and 2, the end of the exhaust path portion 41 is connected to an exhaust port 49 exposed to the outside of the power storage device 1. The gas discharged from at least one of the plurality of power storage elements 20 passes through the exhaust path formed in the exhaust path portion 41 and is discharged to the outside of the power storage device 1 from the exhaust port 49. The structure of the exhaust path portion 41 and its surroundings will be described later with reference to FIGS. 3 to 6.

The substrate 50 is a control substrate that is placed on the inner lid 40 and fixed to the inner lid 40. Specifically, the substrate 50 has a control circuit (not shown), and acquires various information such as a charge state, a discharge state, a voltage value, a current value, and a temperature of a plurality of power storage elements 20. It controls the on / off of the relay and communicates with other devices.

[2. Structure related to exhaust path]
Next, the structure related to the exhaust path in the power storage device 1 according to the present embodiment will be described with reference to FIGS. 3 to 6.

FIG. 3 is a perspective view showing the configuration of the inner lid 40 according to the embodiment. In addition, in FIG. 3, the arrangement area of the adhesive 60 is represented by the area with dots. FIG. 4 is a plan view showing an arrangement region of the adhesive 60 on the side of the plurality of power storage elements 20 according to the embodiment. Specifically, in FIG. 4, the arrangement region of the adhesive 60 when the plurality of power storage elements 20 are viewed in a plan view (when viewed from the plus side in the Z-axis direction) is represented by a region with dots. ..

FIG. 5 is a perspective view showing the positional relationship between the inner lid 40 and the plurality of power storage elements 20 according to the embodiment. Specifically, FIG. 5 shows a perspective view of the power storage device 1 when the exterior body 10 and the inner lid 40 are cut in the YZ plane passing through the exhaust path portion 41 of the inner lid 40, and the substrate 50. The illustration is omitted.

FIG. 6 is a cross-sectional view of the power storage device 1 according to the embodiment. Specifically, FIG. 6 shows a cross-sectional view of the power storage device 1 when the power storage device 1 is cut in a YZ plane passing through the exhaust path portion 41 of the inner lid 40, and the illustration of the substrate 50 is omitted. Moreover, the cross section of the power storage element 20 is simply illustrated.

As shown in FIGS. 3 to 6, in the power storage device 1 according to the present embodiment, the power storage element 20 provided with the discharge unit 27 capable of discharging the internal gas and the exhaust path at a position facing the discharge part 27. It includes an inner lid 40 that forms 41a. Specifically, as shown in FIG. 3, for example, the inner lid 40 has an exhaust path portion 41 which is a portion recessed upward at a position facing the discharge portion 27, and has an inner surface of the exhaust path portion 41. The exhaust path 41a is formed by the space between the storage element 20 and the power storage element 20. That is, when the gas is discharged from the discharge unit 27 of the power storage element 20, the gas passes through the exhaust path 41a and is discharged to the outside of the power storage device 1 from the exhaust port 49 arranged at the end of the exhaust path unit 41. NS.

More specifically, in the present embodiment, as shown in FIGS. 5 and 6, a plurality of power storage elements 20 are arranged in the Y-axis direction, and the discharge unit 27 of each power storage element 20 is also arranged in the Y-axis direction. Be done. The exhaust path portion 41 of the inner lid 40 is arranged at a position facing the discharge portions 27 arranged in this way. As a result, the exhaust path 41a is formed at a position facing the plurality of discharge portions 27.

Further, the inner lid 40 having a portion forming the exhaust path 41a further has a side wall portion that abuts on the side surface of the power storage element 20. In the present embodiment, as shown in FIGS. 5 and 6, the long side surface of the outermost (respectively positive side and negative side in the Y-axis direction) of the plurality of power storage elements 20 arranged in the Y-axis direction. The side wall portion 42 of the inner lid 40 is in contact with the 24a.

As described above, since the side wall portion 42 of the inner lid 40 is in contact with the long side surface 24a of the power storage element 20, the relative movement of the power storage element 20 and the inner lid 40 in the Y-axis direction is restricted. .. Further, the swelling or movement of the power storage element 20 is suppressed by the side wall portion 42.

Further, as shown in FIG. 3, for example, the inner lid 40 has two side wall portions 43 arranged to face each other in the X-axis direction in addition to the two side wall portions 42 arranged to face each other in the Y-axis direction. doing. Each of the two side wall portions 43 is arranged so as to connect the ends of the two side wall portions 42, whereby the outward spread (deformation) of the two side wall portions 42 is suppressed. That is, the side wall portion 43 functions as a member that suppresses the swelling of one or more power storage elements 20 via the side wall portion 42.

In the present embodiment, each of the two side wall portions 43 comes into contact with at least one short side surface 24b when arranged with respect to the plurality of power storage elements 20. For example, the side wall portion 42 is in contact with the long side surface 24a of the outermost power storage element 20 among the plurality of power storage elements 20, and the side wall portion 43 is in contact with the short side surface 24b of the power storage element 20. That is, the inner lid 40 forming the exhaust path 41a has a series of side wall portions (42 and 43) arranged so as to be hooked on the corners of the power storage element group composed of the plurality of power storage elements 20.

Further, in the present embodiment, there is not only the structural engagement as described above, but also a fixed relationship due to the interposition of the adhesive 60 between the power storage element 20 and the inner lid 40. Specifically, as shown in FIGS. 3 and 4, the adhesive 60 is arranged between the inner lid 40 and the discharge surface 23 of the power storage element 20 and in a region along the exhaust path 41a. .. Specifically, in the inner lid 40, the adhesive 60 is arranged so as to fill the space from the outside of the exhaust path portion 41 to the opening 45 in which the electrode terminals 22 of each power storage element 20 are arranged.

As a result, each of the plurality of power storage elements 20 and the inner lid 40 in the present embodiment are adhered to each other by the adhesive material 60, and in a plan view, strips are formed on both sides of the exhaust path 41a (both sides in the X-axis direction). The adhesive 60 will be present. That is, in the present embodiment, the adhesive 60 is arranged so as to suppress the displacement of the inner lid 40 with respect to the plurality of power storage elements 20 and to suppress the leakage of gas from the exhaust path 41a. At the time of assembling the power storage device 1, for example, in a state where the adhesive 60 is applied to the areas on both sides of the exhaust path portion 41 (the areas with dots in FIG. 3) in the inner lid 40. The lid 40 is attached to the plurality of power storage elements 20. After that, the adhesive material 60 is cured, so that the inner lid 40 is fixed to the plurality of power storage elements 20.

Further, as shown in FIGS. 5 and 6, the inner lid 40 is arranged in a state of being engaged with the exterior body 10 which is vertically divided and arranged. For example, as shown in FIG. 6, the exterior body body 12 is fixed to the inner lid 40 in a state of covering a part of the outer surface 42a of the side wall portion 42 of the inner lid 40. Specifically, in the present embodiment, the side wall 12a in the arrangement direction (Y-axis direction) of the plurality of power storage elements 20 in the exterior body body 12 covers a part of the outer surface 42a of the side wall portion 42. The exterior body body 12 and the inner lid 40 are joined. That is, the movement and deformation of the side wall portion 42 of the inner lid 40 is regulated by the side wall 12a of the exterior body body 12.

The method of connecting (joining) the exterior body body 12 and the inner lid 40 is not particularly limited, but for example, the exterior body body 12 and the inner lid 40 are joined by heat welding. Similarly, heat welding is used for joining the outer lid 11 and the inner lid 40.

As described above, a part of the exterior body 10 exists on the outside of the side wall portion 42 that abuts on the power storage element 20. Therefore, for example, the outer body 10 regulates the misalignment of the inner lid 40, and suppresses the swelling of one or more power storage elements 20.

[3. Explanation of effect]
As described above, in the power storage device 1 according to the present embodiment, the power storage element 20 having a discharge surface 23 provided with a discharge unit 27 capable of discharging the internal gas, and an exhaust path at a position facing the discharge unit 27. It is provided with an inner lid 40 which is a path forming member forming 41a. The inner lid 40 has a side wall portion 42 that abuts on the side surface (long side surface 24a in this embodiment) of the power storage element 20 that is connected to the peripheral edge of the discharge surface 23.

As described above, in the present embodiment, the side wall portion 42 of the inner lid 40 is arranged so as to abut on the long side surface 24a of the power storage element 20. That is, the inner lid 40 forming the exhaust path 41a has a structure in which it engages with the power storage element 20 in a direction parallel to the discharge surface 23 of the power storage element 20. As a result, the displacement of the exhaust path 41a (the exhaust path portion 41 of the inner lid 40) with respect to the discharge portion 27 of the power storage element 20 is suppressed. Further, for example, the side wall portion 42 suppresses the swelling of the power storage element 20. That is, the power storage device 1 according to the present embodiment suppresses the swelling of the power storage element 20 that occurs when the power storage element 20 is in a state of discharging gas, and at the same time, shifts in the gas exhaust path 41a due to the swelling. Has a structure that mechanically suppresses. Therefore, the power storage device 1 with improved safety is realized.

Further, in the present embodiment, the power storage device 1 includes a plurality of power storage elements 20 arranged side by side in the first direction (Y-axis direction). Each of the plurality of power storage elements 20 has an electrode body 25 and a container 21 in which the electrode body 25 is housed, and the long side surface 24a of the container 21 is directed in the first direction (Y-axis direction). The short side surface 24b of the container 21 is arranged in a second direction (X-axis direction) orthogonal to the direction (Y-axis direction). In this configuration, the side wall portion 42 faces the long side surface 24a of the outermost power storage element 20 among the plurality of power storage elements 20, and the side wall portion 43 faces the short side surface 24b of the outermost power storage element 20. .. Further, the side wall portion 42 and the side wall portion 43 are continuously formed from the long side surface 24a to the short side surface 24b.

According to this configuration, the exhaust path 41a is suppressed from being displaced from the position facing the discharge unit 27 of the plurality of power storage elements 20. More specifically, the side wall portions 42 and 43 of the inner lid 40 come into contact with the long side surface 24a and the short side surface 24b of the outermost power storage element 20, so that the inner lid 40 moves in the X-axis direction and the Y-axis direction. Is regulated. As a result, the effect of suppressing the displacement of the exhaust path 41a is improved. Further, in the above configuration, since the number of power storage elements 20 is not particularly limited, for example, the power storage device 1 including the number of power storage elements 20 according to the required output voltage or the amount of power storage has improved safety. The power storage device 1 is realized.

Further, in the present embodiment, the inner lid 40 is provided between the inner lid 40 and the discharge surface 23 of the power storage element 20, and the discharge surface 23 is provided by the adhesive 60 arranged along the exhaust path 41a. It is fixed to.

In this way, by interposing the adhesive 60 between the power storage element 20 and the inner lid 40, the deviation of the exhaust path 41a from the regular position is further suppressed. Further, in the present embodiment, since the adhesive 60 extends along the exhaust path 41a so as to cross the plurality of power storage elements 20, the airtightness of the exhaust path 41a can be improved more reliably. As a result, for example, the possibility of gas leaking from an unexpected position in the middle of the exhaust path 41a is reduced.

Further, in the present embodiment, the power storage device 1 includes an exterior body 10 that houses the power storage element 20. The exterior body 10 is fixed to the inner lid 40 in a state of covering at least a part of the outer surface 42a of the side wall portion 42 of the inner lid 40.

According to this configuration, the position of the inner lid 40 with respect to the power storage element 20 is also regulated by the exterior body 10. Therefore, for example, the suppression of the deviation of the exhaust path 41a from the regular position is further ensured. Further, the exterior body 10 functions as a member for suppressing the swelling of the power storage element 20 via the side wall portion 42. Therefore, it is possible to obtain the power storage device 1 with improved safety.

(Other embodiments)
Although the power storage device according to the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. That is, it should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

For example, in the present embodiment, each of the side wall portions 42 and 43 is in contact with the power storage element 20, but for example, the side wall portion 43 does not have to be in contact with the power storage element 20.

Specifically, in the power storage element 20, when the internal pressure of the container 21 rises due to the vaporization of the electrolytic solution inside, the long side surface 24a of the container 21 tends to swell. Therefore, when focusing on suppressing the swelling of the plurality of power storage elements 20 (see, for example, FIG. 2) arranged in the Y-axis direction, each of the long side surfaces 24a at both ends in the Y-axis direction is on the opposite side wall portion 42. It is effective to make contact. From this point of view, the side wall portion 43 facing the short side surface 24b of the plurality of power storage elements 20 does not have to come into contact with the short side surface 24b of the power storage element 20. Even in this case, since the side wall portion 43 is a member that connects the two side wall portions 42 (a member that restrains the spread), it indirectly contributes to suppressing the swelling of one or more power storage elements 20. be able to.

Further, for example, the inner surface of the side wall portion 42 and the long side surface 24a of the power storage element 20 are not completely flat, or the power storage element 20 is arranged in a posture in which the long side surface 24a is not parallel to the side wall portion 42. It is also possible that the side wall portion 42 and the power storage element 20 cannot come into contact with each other in a wide range due to such reasons.

Therefore, a plurality of convex portions (ribs) for contacting the long side surface 24a of the power storage element 20 at a plurality of locations may be provided on the inner surface of the side wall portion 42. FIG. 7 is a perspective view showing the configuration of the inner lid 40 in which a plurality of convex portions 48 are provided on the side wall portion 42.

For example, as shown in FIG. 7, a plurality of convex portions 48 are arranged side by side in the longitudinal direction (X-axis direction) on the side wall portion 42. In this case, for example, the inner lid 40 made of resin is covered with a plurality of power storage elements 20 with elastic deformation, and as a result, each of the plurality of convex portions 48 of the side wall portion 42 is a point or a line, and the side wall portion. It comes into contact with the long side surface 24a of the power storage element 20 adjacent to 42. Thereby, for example, the suppression of the misalignment of the inner lid 40 in the Y-axis direction is further ensured. Further, the effect of suppressing the swelling of the power storage element 20 by the side wall portion 42 is more reliably exhibited.

Further, as shown in FIG. 7, a plurality of convex portions 48 may be arranged side by side in the longitudinal direction (Y-axis direction) on the side wall portion 43. As a result, the side wall portion 43 can be reliably brought into contact with the short side surfaces 24b of the plurality of power storage elements 20. Thereby, for example, the suppression of the displacement of the inner lid 40 in the X-axis direction is further ensured.

Further, although resins such as PC and PP have been exemplified as the material of the inner lid 40, the entire inner lid 40 may not be formed of the resin. For example, the exhaust path portion 41, which is a portion of the inner lid 40 that forms the exhaust path 41a, may be made of a metal member. As a result, the resistance of the inner lid 40 to the heat and pressure of the gas discharged from the power storage element 20 is improved, and as a result, the exhaust path 41a is initially set until, for example, the discharge of the gas from the power storage element 20 is completed. Increased likelihood of being maintained as designed.

Further, the entire inner lid 40 may be made of metal, and in this case, an insulating material such as PC or PP may be arranged at a place where insulation is required.

Further, in the above embodiment, the power storage device 1 includes the outer body 10 and the inner lid 40, but the inner lid 40 may be treated as a part of the outer body 10. That is, the inner lid 40 is a part of a member that covers one or more power storage elements 20 from the outside, and from this viewpoint, it can be said that the inner lid 40 is a part of the exterior body 10.

Further, in the above embodiment, the connecting member 30 and the electrode terminal 22 are joined by welding. However, the connecting member 30 and the electrode terminal 22 may be joined by another method. For example, the connecting member 30 and the electrode terminal 22 may be joined by a method such as caulking with rivets or screwing.

In addition, the number and shape of the power storage elements 20 included in the power storage device 1 do not have to be the number and shape described in the above embodiment. For example, the number of power storage elements 20 may be 1 to 3 or 5 or more, and the shape of the power storage elements 20 may be, for example, a columnar shape.

Further, a form constructed by arbitrarily combining the components included in the above-described embodiment and its modifications is also included in the scope of the present invention.

The present invention can be applied to a power storage device including a power storage element such as a lithium ion secondary battery.

1 Power storage device 10 Exterior body 11 Outer lid 12 Exterior body body 12a Side wall 13 External terminal 17 External terminal 20 Power storage element 21 Container 22 Electrode terminal 23 Discharge surface 24a Long side surface 24b Short side surface 25 Electrode body 27 Discharge part 30 Connection member 40 Inner lid (Path forming member)
41 Exhaust path 41a Exhaust path 42, 43 Side wall 42a Outer surface 45 Opening 48 Convex 49 Exhaust port 50 Board 60 Adhesive

Claims (3)

A power storage element having a discharge surface provided with a discharge unit capable of discharging internal gas,
A path forming member for forming an exhaust path at a position facing the discharge portion is provided.
The path forming member has a side wall portion of the power storage element that abuts on a side surface connected to the peripheral edge of the discharge surface.
Further, an exterior body for accommodating the power storage element is provided.
The exterior body is fixed to the path forming member with the side wall portion of the path forming member sandwiched between the side wall of the exterior body and the side surface of the power storage element.
Power storage device. A plurality of the power storage elements arranged side by side in the first direction are provided.
Each of the plurality of power storage elements
It has an electrode body and a container in which the electrode body is housed.
The container is arranged so that the long side surface of the container faces the first direction and the short side surface of the container faces the second direction orthogonal to the first direction.
The side wall portion faces the long side surface and the short side surface of the outermost power storage element among the plurality of power storage elements, and is formed continuously from the long side surface to the short side surface.
Claim 1 Symbol placement of the power storage device. The path forming member is between the path forming member and the discharging surface of the power storage element.
Moreover, it is fixed to the exhaust surface by the adhesive material arranged along the exhaust path.
The power storage device according to claim 1 or 2.

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