JP5734076B2 - Power storage device and power storage module - Google Patents

Description

  The present invention relates to a power storage device and a power storage module.

  A sealed storage cell having a structure in which an electrode stack including a positive electrode and a negative electrode is housed in an outer package together with an electrolyte and sealed is known.

  When a voltage outside the standard range is applied when using such a sealed storage cell, the electrolyte solvent reacts with the positive or negative active material, and as a result, gas may be generated in the sealed space. . In addition, even when the sealed storage cell is used under a high temperature condition outside the standard range, gas may be generated due to decomposition of the electrolyte salt or the like.

  In order to release the gas generated in this way and prevent the outer package from rupturing, a technique of providing a safety valve on the outer package is known. For example, in Patent Document 1, a member for discharging gas is provided between an assembled battery and an upper cover that covers the assembled battery, and gas is simply passed through a channel formed by covering the member with the upper cover. A technique for discharging in the battery stacking direction is disclosed. Patent Document 2 discloses a technique for discharging gas in the stacking direction of battery cells by assembling a discharge passage to a gas discharge port provided on a side surface of a cell case that houses battery cells.

JP 2002-151025 A JP 2006-236605 A

  The flow path for discharging the gas preferably has a large volume. When the volume of the flow path is small, the gas pressure increases in the flow path, and the gas may be released violently. In particular, since the gas released from the exterior body is high temperature, an electricity storage device having high safety is required.

  One of the objects according to some embodiments of the present invention is to provide an electricity storage device having high safety. Another object of some aspects of the present invention is to provide a power storage module having the power storage device.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
One aspect of the electricity storage device according to the present invention is:
A storage cell having a positive electrode, a negative electrode, and an outer package containing an electrolyte; and
A cell case sandwiching the storage cell;
Including
The exterior body has a main body part, and an outer peripheral part provided around the main body part,
The outer periphery is
A first portion sandwiched by the cell case;
A second part serving as a safety valve for releasing the gas in the exterior body;
Have
The cell case has a discharge channel for discharging the gas released from the second portion,
The discharge flow path extends along the outer peripheral portion.

[Application Example 2]
In application example 1,
The exterior body has a planar shape having a long side and a short side,
The discharge flow path may extend along the long side.

[Application Example 3]
In application example 1 or 2,
The cell case has a base and a lid,
The base has a placement portion for placing the first portion;
The lid is
A covering portion covering the body portion;
A protrusion formed around the covering portion and protruding toward the base;
Have
The first portion may be sandwiched between the placing portion and the protruding portion.

[Application Example 4]
In application example 3,
A recess may be formed in the placement portion along the second portion.

[Application Example 5]
In application example 4,
The base has a side wall provided around the mounting portion,
The lid has a bent portion provided on the outer periphery of the lid,
The side wall portion and the bent portion form the discharge flow path,
A communication portion that communicates with the recess and the discharge channel may be formed in the side wall portion.

[Application Example 6]
In any one of Application Examples 3 to 5,
In the mounting portion, an opening is formed,
The main body may be disposed in the opening.

[Application Example 7]
In any one of Application Examples 1 to 6,
A liquid absorbing member that absorbs the electrolytic solution discharged from the second portion may be provided in the discharge channel.

[Application Example 8]
In any one of Application Examples 1 to 7,
The storage cell may be a lithium ion capacitor.

[Application Example 9]
A plurality of power storage devices according to any one of Application Examples 1 to 8 are stacked,
The plurality of power storage devices may be electrically connected.

[Application Example 10]
In application example 9,
The storage cell is
A positive electrode terminal electrically connected to the positive electrode;
A negative electrode terminal electrically connected to the negative electrode,
An insulating cover portion surrounding the positive electrode terminal and the negative electrode terminal may be formed on the base.

  According to the electricity storage device of the present invention, the entire length of the discharge channel can be increased along the outer peripheral portion of the exterior body. Thereby, in the electrical storage device which concerns on this invention, the capacity | capacitance of an exhaust flow path can be enlarged easily compared with the form which provided the exhaust flow path along the thickness direction of an electrical storage cell, for example. Therefore, it can suppress that the pressure of the gas in a discharge flow path becomes high. Furthermore, high-temperature (for example, about 300 ° C.) gas can be efficiently cooled. Therefore, the electricity storage device according to the present invention can have high safety.

The disassembled perspective view which shows typically the electrical storage device which concerns on this embodiment. The perspective view which shows typically the electrical storage device which concerns on this embodiment. Sectional drawing which shows typically the electrical storage device which concerns on this embodiment. FIG. 3 is a cross-sectional perspective view schematically showing the electricity storage device according to the present embodiment. Sectional drawing which shows typically the electrical storage cell of the electrical storage device which concerns on this embodiment. The perspective view which shows typically the base | substrate of the electrical storage device which concerns on this embodiment. The figure which shows typically the cover body of the electrical storage device which concerns on this embodiment. Sectional drawing which shows typically the cover body of the electrical storage device which concerns on this embodiment. Sectional drawing which shows typically the cover body of the electrical storage device which concerns on this embodiment. Sectional drawing which shows typically the cover body of the electrical storage device which concerns on this embodiment. Sectional drawing which shows typically the cover body of the electrical storage device which concerns on this embodiment. Sectional drawing which shows typically the cover body of the electrical storage device which concerns on this embodiment. The cross-sectional perspective view which shows typically the electrical storage device which concerns on the modification of this embodiment. The disassembled perspective view which shows typically the electrical storage module which concerns on this embodiment. The figure which shows typically the electrical storage module which concerns on this embodiment. The perspective view which shows typically the electrical storage module which concerns on this embodiment. The perspective view which shows typically a part of electrical storage module which concerns on this embodiment.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

1. Power Storage Device First, a power storage device according to this embodiment will be described with reference to the drawings. FIG. 1 is an exploded perspective view schematically showing an electricity storage device 100 according to the present embodiment. FIG. 2 is a perspective view schematically showing the electricity storage device 100 according to this embodiment. 3 is a cross-sectional view taken along the line III-III in FIG. 2 (for example, a cross-sectional view in the YZ plane) schematically showing the electricity storage device 100 according to the present embodiment. FIG. 4 is a perspective view schematically showing the electricity storage device 100 according to the present embodiment, including a cross-sectional view taken along line IV-IV in FIG.

  As shown in FIGS. 1 to 4, the electricity storage device 100 includes an electricity storage cell 10 and a cell case 30.

1.1. About a storage cell As a form of the storage cell 10, a lithium ion capacitor, a secondary battery, an electric double layer capacitor etc. can be illustrated. As shown in FIG. 1, the storage cell 10 can include an exterior body 12, a positive electrode terminal 20, and a negative electrode terminal 22.

  The exterior body 12 contains a positive electrode, a negative electrode, and an electrolytic solution. The shape of the outer package 12 is not particularly limited as long as it can accommodate the positive electrode, the negative electrode, and the electrolytic solution. For example, the outer package 12 is a laminate type in which two laminate films are bonded together. 3 and 4, for convenience, the positive electrode, the negative electrode, and the like housed in the exterior body 12 are omitted.

  As the laminate film, for example, a metal foil such as an aluminum foil or a copper foil sandwiched between synthetic resins such as polypropylene or nylon can be used. By using such a film-shaped exterior body 12, for example, compared with the case where a hard exterior body (metal can etc.) which consists of metals etc. is used, size reduction and weight reduction of the electrical storage cell 10 can be achieved. .

  As shown in FIG. 1, the exterior body 12 includes a main body portion 13 and an outer peripheral portion 14 provided around the main body portion 13. The main body 13 accommodates an electrode laminate including a positive electrode and a negative electrode. The thickness (length in the Z-axis direction) of the main body portion 13 is, for example, larger than the thickness of the outer peripheral portion 14 and is, for example, 1 mm or more and 10 mm or less. The exterior body 12 may be formed by thermocompression bonding two laminated films at the outer peripheral portion 14. The exterior body 12 has a rectangular shape in plan view (viewed from the Z-axis direction), and can include a long side 17 and a short side 18.

  The outer peripheral part 14 has the 1st part 15 clamped by the cell case 30, and the 2nd part 16 used as a safety valve. The first portion 15 can have a terminal clamping portion 15 a that sandwiches the terminals 20 and 22. The terminal clamping part 15a may be displaced in the Z-axis direction by the thickness of the terminals 20 and 22 with respect to the other part of the first part 15 (the first part 15 other than the terminal clamping part 15a). In the illustrated example, the terminal clamping portion 15 a is provided in a portion along the short side 18 of the outer peripheral portion 14.

  For example, the second portion 16 is provided in a portion along the long side 17 of the outer peripheral portion 14. In the illustrated example, the second portion 16 is provided at the center of the portion along the long side 17 of the outer peripheral portion 14. The second portion 16 is, for example, a portion in which the adhesion between two laminated films is lower than that of the first portion 15. Therefore, the second portion 16 is preferentially peeled prior to the first portion 15 when the pressure in the sealed space containing the positive electrode, the negative electrode, and the electrolytic solution reaches a predetermined value. Thereby, even if gas is generated in the exterior body 12, the electricity storage cell 10 can release the pressure by releasing the gas from the second portion 16. As a result, the exterior body 12 can be prevented from bursting.

  The positive electrode terminal 20 and the negative electrode terminal 22 are provided so as to extend from the exterior body 12. More specifically, the positive electrode terminal 20 and the negative electrode terminal 22 extend from the main body 13 through the outer peripheral portion 14 to the outside of the outer package 12 while maintaining the hermeticity of the outer package 12. The positive terminal 20 and the negative terminal 22 extend in opposite directions. Part of the terminals 20 and 22 is exposed from the lid 70.

  Although the shape of the positive electrode terminal 20 is not particularly limited, in the illustrated example, the positive electrode terminal 20 has a connection portion 20 a positioned above (in the + Z direction) the outer peripheral portion 14 of the exterior body 12. For example, when the electricity storage device 100 is stacked (see FIG. 14), the positive electrode terminal 20 can be easily connected to the negative electrode terminal 22 of the adjacent electricity storage device 100 by the connecting portion 20a. For example, a through hole 24 is provided in the connection portion 20a. By arranging the through hole 24 and the through hole 27 of the washer 26 so as to communicate with each other, and passing the screw 28 through the through holes 24 and 27, the positive terminal 20 is connected to the terminal fixing portion 46 of the base body 40 (see FIG. 3). Can be fixed to. When the electricity storage device 100 is stacked, the positive electrode terminal 20 may be fixed to the terminal fixing portion 46 by the washer 26 and the screw 28 in a state of being connected to the negative electrode terminal 22 of the upper adjacent electricity storage device 100.

  Although the shape of the negative electrode terminal 22 is not particularly limited, in the illustrated example, the negative electrode terminal 22 has a connection portion 22 a located below (−Z direction) the outer peripheral portion 14 of the exterior body 12. For example, when the electricity storage device 100 is stacked (see FIG. 14), the negative electrode terminal 22 can be easily connected to the positive electrode terminal 20 of the adjacent electricity storage device 100 by the connecting portion 22a. When the power storage device 100 is stacked, the negative electrode terminal 22 is connected to the positive electrode terminal 20 of the lower adjacent power storage device 100 and is fixed to the terminal fixing portion 46 (see FIG. 3) of the lower adjacent power storage device 100 by a washer and a screw. Reference) may be fixed.

  The positive terminal 20 is electrically connected to the positive electrode in the exterior body 12. The negative electrode terminal 22 is electrically connected to the negative electrode in the exterior body 12. Examples of the material of the positive electrode terminal 20 include aluminum. Examples of the material of the negative electrode terminal 22 include copper and nickel.

  In the illustrated example, the terminal extending in the + Y direction from the outer package 12 is the positive electrode terminal 20 and the terminal extending in the −Y direction from the outer package 12 is the negative electrode terminal 22. A terminal extending in the −Y direction from 12 may be a positive terminal, and a terminal extending in the + Y direction from the outer package 12 may be a negative terminal.

  Next, the internal structure of the electricity storage cell 10 of the electricity storage device 100 will be described. FIG. 5 is a cross-sectional view showing the storage cell 10, and is a cross-sectional view schematically showing the internal structure (of the outer package 12) of the storage cell 10. Below, the case where the electrical storage cell 10 is a lithium ion capacitor is demonstrated as an example.

  The electrical storage cell 10 can have the electrode laminated body 5 and the electrolyte solution (not shown) accommodated in the exterior body 12, as shown in FIG. In the illustrated example, the electrode laminate 5 and the electrolytic solution are accommodated in an exterior body 12 composed of a first laminate film 12a and a second laminate film 12b.

  The electrode laminate 5 is immersed in the electrolytic solution. The electrode laminate 5 includes a positive electrode 1, a negative electrode 2, a lithium electrode 3, and a separator 4. The positive electrode 1, the negative electrode 2, the lithium electrode 3, and the separator 4 have a sheet shape. In the illustrated example, the electrode laminate 5 is laminated in the order of the lithium electrode 3, the negative electrode 2, the positive electrode 1, the negative electrode 2, the positive electrode 1, the negative electrode 2, and the lithium electrode 3 from the first laminate film 12 a side. And a separator 4 between the electrode and the laminate film. In the electrode laminate 5, the positive electrode 1 and the negative electrode 2 are connected in parallel.

  The number of positive electrodes 1 and negative electrodes 2 is not particularly limited. Similarly, the number of lithium electrodes 3 and the installation location are not particularly limited. Moreover, the form of the electrode laminated body 5 is not limited to the example of illustration, For example, the positive electrode, the negative electrode, the lithium electrode, and the separator are laminated | stacked, a laminated sheet is formed, and this laminated sheet is wound and formed. But you can.

  The positive electrode 1 can include a positive electrode current collector 1a and a positive electrode active material layer 1b. As the positive electrode current collector 1a, a porous metal foil can be used. Examples of the material of the positive electrode current collector 1a include aluminum and stainless steel. The thickness of the positive electrode current collector 1a is, for example, 15 μm or more and 50 μm or less. The positive electrode current collector 1 a is connected to the positive electrode terminal 16 through the positive electrode lead 6. The material of the positive electrode lead 6 is, for example, the same as the material of the positive electrode current collector 1a.

  The positive electrode active material layer 1b is formed on the positive electrode current collector 1a. In the illustrated example, the positive electrode active material layer 1b is formed on both surfaces of the positive electrode current collector 1a, but may be formed only on one surface. The thickness of the positive electrode active material layer 1b is, for example, not less than 30 μm and not more than 90 μm.

The positive electrode active material layer 1b contains a positive electrode active material. The positive electrode active material is a material that can reversibly support anions such as hexafluorophosphate (PF ₆ ⁻ ) and tetrafluoroborate (BF ₄ ⁻ ). More specifically, examples of the positive electrode active material include activated carbon and a polyacene-based material (PAS) that is a heat-treated product of an aromatic condensation polymer.

  As a method for forming the positive electrode active material layer 1b, first, a positive electrode active material powder and a binder are dispersed in an aqueous medium or an organic solvent to prepare a slurry. You may mix electroconductive powder as needed. Next, the adjusted slurry is applied to the surface of the positive electrode current collector 1a and dried. Thus, the positive electrode active material layer 1b can be obtained.

  The negative electrode 2 can have a negative electrode current collector 2a and a negative electrode active material layer 2b. As the negative electrode current collector 2a, a porous metal foil can be used. Examples of the material of the negative electrode current collector 2a include copper, stainless steel, and nickel. The thickness of the negative electrode current collector 2a is, for example, 10 μm or more and 50 μm or less. The negative electrode current collector 2 a is connected to the negative electrode terminal 18 through the negative electrode lead 7. The material of the negative electrode lead 7 is the same as the material of the negative electrode current collector 2a, for example.

  The negative electrode active material layer 2b is formed on the negative electrode current collector 2a. In the illustrated example, the negative electrode active material layer 2b is formed on both surfaces of the negative electrode current collector 2a, but may be formed only on one surface. The thickness of the negative electrode active material layer 2b is, for example, 20 μm or more and 50 μm or less.

  The negative electrode active material layer 2b contains a negative electrode active material. The negative electrode active material is a material that can reversibly store lithium ions. More specifically, examples of the negative electrode active material include graphite (graphite), non-graphitizable carbon (hard carbon), and pulverized products thereof.

  As a method for forming the negative electrode active material layer 2b, first, a negative electrode active material powder and a binder are dispersed in an aqueous medium or an organic solvent to prepare a slurry. You may mix electroconductive powder as needed. Next, the adjusted slurry is applied to the surface of the negative electrode current collector 2a and dried. In this way, the negative electrode active material layer 2b can be obtained.

  The lithium electrode 3 includes a lithium electrode current collector 3a and a lithium foil 3b. As the lithium electrode current collector 3a, a porous metal foil can be used. Examples of the material of the lithium electrode current collector 3a include copper and stainless steel. The thickness of the lithium electrode current collector 3a is, for example, not less than 10 μm and not more than 200 μm.

  The lithium foil 3b is, for example, pressure bonded to one surface of the lithium electrode current collector 3a. The material of the lithium foil 3b is lithium. The lithium foil 3b can function as a lithium ion supply source. That is, when the lithium electrode current collector 3a and the negative electrode current collector 2a are connected via the negative electrode lead 7 and short-circuited, the lithium foil 3b can be dissolved in the electrolytic solution and become lithium ions. Then, the lithium ions are electrochemically doped into the negative electrode active material layer 2b (also referred to as “pre-dope”) via the electrolytic solution. As a result, the potential of the negative electrode 2 can be lowered. Thereby, an energy density can be enlarged. The thickness of the lithium foil 3b is, for example, 50 μm or more and 300 μm or less.

  Note that the lithium foil 3b is completely dissolved in the electrolytic solution by pre-doping, for example, but in the illustrated example, the electrolytic solution is omitted for convenience and the lithium foil 3b before being dissolved in the electrolytic solution is illustrated. .

As the electrolytic solution, an aprotic organic solvent electrolyte solution containing lithium salt as an electrolyte can be used. Examples of the aprotic organic solvent include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, acetonitrile, dimethoxyethane, tetrahydrofuran, dioxolane, methylene chloride, sulfolane and the like. These solvents may be used alone or in combination of two or more. Examples of the lithium salt include LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , Li (C ₂ F ₅ SO ₂ ) ₂ N, and the like.

  For the separator 4, a porous material having durability against the positive electrode active material, the negative electrode active material, and the electrolyte can be used. As the separator 4, a nonwoven fabric made of cellulose, rayon, cellulose / rayon, polyethylene, polypropylene, aramid resin, amideimide, polyphenylene sulfide, polyimide, or the like, a porous film, or the like can be used. The thickness of the separator 4 is 20 μm or more and 50 μm or less, for example. The separator can isolate between the positive electrode 1 and the negative electrode 2 or between the negative electrode 2 and the lithium electrode 3. Further, the separator 4 can infiltrate the electrolyte.

1.2. Cell Case The cell case 30 can hold the storage cell 10. The shape of the cell case 30 is not particularly limited as long as the storage cell 10 can be sandwiched. The cell case 30 can include a base body 40 and a lid body 70.

1.2.1. Substrate The material of the substrate 40 is not particularly limited, and is, for example, a resin such as plastic. Here, FIG. 6 is a perspective view schematically showing the base body 40, as viewed from a direction different from FIG.

  As shown in FIGS. 1 and 6, the base body 40 includes a placement portion 41 and a side wall portion 50 provided around the placement portion 41.

  The placement portion 41 can constitute the bottom portion of the base body 40. The placement portion 41 is formed along the first portion 15 of the exterior body 12, for example. As shown in FIGS. 3 and 4, the mounting portion 41 can mount the first portion 15.

  The mounting part 41 can have a terminal support part 42 as shown in FIGS. 1 and 6. The terminal support portion 42 is a portion having a smaller thickness than the other portion of the placement portion 41 (the placement portion 41 other than the terminal support portion 42). As shown in FIG. 3, the terminal support portion 42 can support the terminal holding portion 15 a of the exterior body 12.

  As shown in FIG. 3, for example, a stepped portion 46 is formed in the mounting portion 41. The step portion 46 can have a thickness larger than that of the placement portion 41. The step portion 46 may be provided adjacent to the terminal support portion 42 that supports the positive electrode terminal 20. The positive electrode terminal 20 can be fixed to the base body 40 by sandwiching the positive electrode terminal 20 between the stepped portion 46 and the washer 26 and fixing with the screw 28. The step portion 46 may be formed integrally with the placement portion 41.

  As shown in FIGS. 1 and 6, the mounting portion 41 is formed with a recess 43. The recessed part 43 is provided along the 2nd part 16 of the exterior body 12, for example. That is, the second portion 16 is disposed above the recess 43. Thereby, the second portion 16 can be separated from the base body 40. Therefore, when the gas is released from the second portion 16, it is possible to prevent the release of gas from being suppressed by the base body 40.

  For example, an opening 44 is formed in the mounting portion 41. The opening 44 penetrates the placement portion 41 in the thickness direction. The planar shape of the opening 44 is not particularly limited, but is rectangular in the illustrated example. As shown in FIGS. 3 and 4, the main body 13 of the exterior body 12 may be disposed in the opening 44. Thereby, when gas is generated in the exterior body 12, the main body 13 can swell, and the pressure in the exterior body 12 can be reduced accordingly. Furthermore, when the electricity storage device 100 is stacked, the main body 13 can be in contact with not only the lid 70 above the main body 13 but also the lid 70 of the adjacent energy storage cell 100 by swelling. That is, the main body 13 can be sandwiched between the lids 70 made of a metal with high heat dissipation. Thereby, the heat dissipation of the electrical storage cell 10 can be improved.

  As shown in FIGS. 1 and 6, the side wall portion 50 is provided around the placement portion 41. The side wall portion 50 extends in the Z-axis direction from the placement portion 41. In the illustrated example, the side wall 50 has two first side wall parts 51 a and 51 b along the long side 17 and two second side wall parts 52 a and 52 b along the short side 18. The first side wall portions 51a and 51b may be disposed to face each other. The second side wall portions 52a and 52b may be disposed to face each other.

  A first communication portion 53 that communicates with the recess 43 is formed in the first side wall portion 51a. The first communication part 53 penetrates the first side wall part 51a in the X-axis direction. Although the number of the 1st communication parts 53 is not specifically limited, In the example of illustration, two are provided. Although the shape of the 1st communication part 53 is not specifically limited, In the example of illustration, it is a rectangle. The first communication portion 53 can guide the gas to the discharge channel 32 (see FIG. 4) when the gas is released from the second portion 16.

  As shown in FIG. 6, a second communication portion 54 may be formed on the first side wall portion 51 a. The second communication part 54 penetrates the first side wall part 51a in the X-axis direction. In the illustrated example, two second communication portions 54 are provided, and the two first communication portions 53 are sandwiched therebetween. The first communication part 53 and the second communication part 54 may be arranged as an example. The second communication portion 54 is formed adjacent to the first portion 15 of the exterior body 12. The second communication portion 54 allows the gas released from the second portion 16 to flow into the discharge flow path 32 when the gas flows out in the vicinity of the first portion 15 sandwiched between the base body 40 and the lid body 70. Can lead.

  For example, a cutout portion 55 is formed in the first side wall portions 51a and 51b. The cutout portion 55 penetrates the first side wall portions 51a and 51b in the X-axis direction, and further penetrates the placement portion 41 in the X-axis direction. The notch 55 is formed below the communication parts 53 and 54, for example. The notch portion 55 may be formed by notching the lower side of the first side wall portions 51 a and 51 b and the placement portion 41. Although the number of the notch parts 55 is not specifically limited, In the example of illustration, six each is provided in the 1st side wall parts 51a and 51b. The shape of the notch 55 is not particularly limited, but is a rectangle in the illustrated example. The cutout portion 55 formed in the first side wall portion 51a and the cutout portion 55 formed in the first side wall portion 51b may be disposed to face each other. The notch 55 can function as a vent formed between adjacent power storage devices 100, particularly when a plurality of power storage devices 100 are stacked (see FIG. 15). That is, the heat dissipation of the storage cell 10 can be improved by the notch 55.

  As shown in FIGS. 1 and 6, a hook 56 may be provided on the first side walls 51 a and 51 b. In the illustrated example, two hooks 56 are provided on the first side walls 51a and 51b, but the number thereof is not particularly limited. Although not shown, the hook 56 may be provided on the second side walls 52a and 52b. The hook 56 can be inserted into the opening 79 of the lid 70 and hooked on the lid 70. Thereby, the base 40 and the lid 70 can be connected. The shapes of the hook 56 and the opening 79 are not particularly limited as long as the base body 40 and the lid 70 can be connected.

  For example, a cover portion 57 is formed on the second side wall portion 52a. The cover part 57 is exposed from the lid body 70. The cover part 57 surrounds the positive electrode terminal 20, for example. The cover part 57 extends in the Z-axis direction from the second side wall part 52a. The cover part 57 has insulation. By the cover part 57, it can suppress that the positive electrode terminal 20 contacts a conductive member (not shown), for example, and short-circuits. Furthermore, when the power storage device 100 is stacked on the top and bottom, it becomes easy to stack. Although not shown, the cover portion 57 may surround the negative electrode terminal 22.

  The cover portion 57 may be formed as a member different from the base body 40, but is preferably formed integrally with the base body 40. Thereby, the number of parts of the electrical storage device 100 can be reduced, and a manufacturing man-hour can be reduced.

  For example, a notch 58 is formed in the second side wall 52b. The negative electrode terminal 22 can extend out of the cell case 30 through the notch 58. The negative electrode terminal 22 is connected to the positive electrode terminal 20 of the lower adjacent power storage device 100 when a plurality of the power storage devices 100 are stacked (see FIG. 14), and the cover portion 57 of the lower adjacent power storage device 100 is connected. It may be surrounded by.

  The base body 40 can have a stacking fixing portion 60. The stacking fixing portion 60 is exposed from the lid body 70. The stacking fixing part 60 is arranged at a corner of the side wall part 50. More specifically, the stacking fixing portion 60 is disposed at a connection portion between the first side wall portions 51a and 51b and the second side wall portions 52a and 52b. A through hole 61 penetrating in the Z-axis direction is formed in the stacking fixing portion 60. For example, when a plurality of power storage devices 100 are stacked (see FIG. 14), the plurality of power storage devices 100 can be fixed by passing screws through the through holes 61.

1.2.2. Regarding the lid body Examples of the material of the lid body 70 include metals such as aluminum, iron, and copper, and resins. However, considering the heat dissipation of the special electric cell 10, a metal is preferable. Here, FIG. 7 is a plan view schematically showing the lid 70. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG.

  The lid 70 can include a covering portion 71, a protruding portion 72, and a bent portion 74.

  The covering portion 71 can cover the main body portion 13 of the exterior body 12. The shape of the covering portion 71 is not particularly limited as long as it can cover the main body portion 13. For example, in plan view, the area of the covering portion 71 is equal to or larger than the area of the main body portion 13, but considering the downsizing of the power storage device 100, it is preferable that the area is the same as the area of the main body portion 13. The covering portion 71 may be in contact with the main body portion 13 or may be separated by a distance of about 1 mm.

  The protruding portion 72 is provided around the covering portion 71. The protruding portion 72 protrudes closer to the base body 40 (in the −Z direction) than the covering portion 71. The protrusion 72 is provided along the first portion 15 of the exterior body 12. As shown in FIGS. 3 and 4, the first portion 15 is sandwiched between the placing portion 41 and the protruding portion 72. That is, the placing portion 41 and the protruding portion 72 can be pressed with the first portion 15 interposed therebetween. Thereby, the cell case 30 can clamp the electrical storage cell 10.

  As shown in FIGS. 7 and 8, the lid 70 can have a small protrusion 73 having a smaller degree of protrusion than the protrusion 72 (the length in the Z-axis direction is small). The small protrusion 73 is provided along the second portion 16 of the exterior body 12. That is, the small protrusion 73 is provided above the second portion 16. Thereby, the second portion 16 can be separated from the lid 70. Therefore, when the gas is released from the second portion 16, it is possible to prevent the gas release from being suppressed by the lid body 70.

  Although not shown, the small protrusion 73 is not provided, and the portion located above the second portion 16 of the lid 70 may be a flat portion continuous with the covering portion 71. In the example shown in FIG. 4, the second portion 16 is separated from the base body 40 and the lid body 70, but the second portion 16 is not limited to suppress the release of gas. 70 may be in contact.

  The bent portion 74 is provided on the outer periphery of the lid body 70. For example, the bent portion 74 is provided along the long side 17 of the exterior body 12. As shown in FIG. 4, the bent portion 74 and the first side wall portion 51 a can form the discharge channel 32. The cross-sectional shape of the bent portion 74 is not particularly limited as long as the discharge channel 32 can be formed.

  In the illustrated example, the bent portion 74 includes a first flow path forming portion 74a having a height similar to that of the covering portion 71, a second flow path forming portion 74b disposed to face the first wall-shaped member 51a, A third flow path forming member 74c disposed opposite to the first flow path forming portion 74a. The first flow path forming portion 74a and the second flow path forming portion 74b may be orthogonal to each other. The 2nd flow path formation part 74b and the 3rd flow path formation part 74c may be orthogonally crossed. The third flow path forming part 74c and the first side wall part 51a may be separated from or in contact with each other. In consideration of downsizing of the electricity storage device 100, the length of the second flow path forming portion 74b in the Z-axis direction is preferably equal to or less than the length of the first wall member 51a in the Z-axis direction.

  Note that the cross-sectional shape of the bent portion 74 is not limited to the above shape, and as shown in FIG. 10, the third flow path forming portion 74c extends obliquely upward from the second flow path forming portion 74b. It may be. Further, as shown in FIG. 11, the cross-sectional shape of the second flow path forming portion 74b may be an arc shape. As shown in FIG. 12, the cross-sectional shape of the second flow path forming portion 74b may be a bent shape. 10 to 12 are cross-sectional views schematically showing the lid according to the present embodiment, and correspond to FIG.

  As shown in FIG. 4, the cell case 30 has a discharge channel 32. The discharge flow path 32 extends along the outer peripheral portion 14 of the exterior body 12. More specifically, the discharge flow path 32 extends along the long side 17 of the exterior body 12. As described above, the discharge channel 32 is formed by the bent portion 74 and the first side wall portion 51a. The discharge flow path 32 can discharge the gas to the outside when the gas is discharged from the second portion 16 of the exterior body 12. More specifically, the gas released from the second portion 16 is introduced into the discharge flow path 32 through the first communication portion 53 and collides with the second flow path forming portion 74 b of the bent portion 74. The collided gas can be divided into a gas that travels in the + Y direction in the discharge flow channel 32 and a gas that travels in the -Y direction in the discharge flow channel 32. And, for example, through the gap formed between the discharge flow path 32 and the stacking fixing portion 60 or the gap formed between the third flow path forming portion 74c and the first side wall portion 51a, the outside Can be discharged.

  The lid body 70 may be formed, for example, by processing one plate-like member. Specific processing methods include press processing, mold processing, stereolithography, and machining. Thereby, the coating | coated part 71, the protrusion part 72, the bending part 74, etc. can be formed integrally. Therefore, the number of parts of the electricity storage device 100 can be reduced, and the number of manufacturing steps can be reduced.

1.3. Regarding Operational Effects, etc. According to the electricity storage device 100, the cell case 30 has the discharge flow path 32 for discharging the gas when the gas is released from the second portion 16 of the exterior body 12. The path 32 extends along the outer peripheral portion 14 of the exterior body 12. Therefore, in the electricity storage device 100, the entire length of the discharge channel 32 can be increased along the outer peripheral portion 14 of the exterior body 12. Thereby, in the electrical storage device 100, the capacity | capacitance of the discharge flow path 32 can be enlarged easily compared with the form which provided the discharge flow path along the thickness direction (Z-axis direction) of an electrical storage cell, for example. Therefore, it can suppress that the pressure of the gas in the discharge flow path 32 becomes high. Furthermore, high-temperature (for example, about 300 ° C.) gas can be efficiently cooled. Therefore, the electricity storage device 100 can have high safety.

  According to the electricity storage device 100, the discharge flow path 32 can extend along the long side 17 of the exterior body 12. Therefore, the electrical storage device 100 can lengthen the full length of the discharge flow path 32 compared with the form which has the discharge flow path along the short side of an exterior body.

  According to the electricity storage device 100, the first portion 15 of the exterior body 12 can be sandwiched between the mounting portion 41 of the base body 40 and the protruding portion 72 of the lid body 70. Therefore, the storage cell 10 can be stably held by the base body 40 and the lid body 70. Furthermore, a recess 43 can be formed in the mounting portion 41 along the second portion 16 of the exterior body 12. Therefore, when the gas is released from the second portion 16, it is possible to prevent the release of gas from being suppressed by the base body 40.

  According to the electricity storage device 100, the discharge channel 32 can be formed by the side wall portion 51 a of the base body 40 and the bent portion 74 of the lid body 70. Therefore, since no new member is required to form the discharge flow path 32, the number of components of the power storage device 100 can be reduced, and the number of manufacturing steps can be reduced. Furthermore, the power storage device 100 can be made compact, and the energy density can be improved.

  According to the electricity storage device 100, the opening portion 44 is formed in the mounting portion 41, and the main body portion 13 of the exterior body 12 can be disposed in the opening portion 44. Thereby, when gas is generated in the exterior body 12, the main body 13 can swell, and the pressure in the exterior body 12 can be reduced accordingly.

  In addition, the electrical storage device 100 can be applied to, for example, in-vehicle applications such as an automatic transporter, an automobile, and a forklift, and stationary applications such as a power generation apparatus and a wind power generation apparatus.

2. Next, a power storage device according to a modification of the present embodiment will be described with reference to the drawings. FIG. 13 is a cross-sectional view schematically showing an electricity storage device 200 according to a modification of the present embodiment, and corresponds to FIG. Hereinafter, in the power storage device 200 according to the modification of the present embodiment, members having the same functions as those of the constituent members of the power storage device 100 according to the present embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the electricity storage device 200, as shown in FIG. 13, a liquid absorption 34 is provided in the discharge channel 32. The liquid absorption 34 can absorb the discharged electrolytic solution when the electrolytic solution in the outer package 12 is released from the second portion 16 as the gas is released. Thereby, it can suppress that the discharged | emitted electrolyte solution flows out outside, and an electric corrosion etc. generate | occur | produce. The absorber 34 may be provided only at a position adjacent to the communication portion 53 (see FIG. 4), or may be provided by filling the entire discharge channel 32.

  The absorber 34 can be made of a material that can absorb the electrolytic solution and does not hinder the flow of gas. More specifically, examples of the material of the absorbent body 34 include absorbent cotton, sponge, urethane foam, asbestos, and non-woven fabric.

  According to the electricity storage device 200, it is possible to suppress the occurrence of electrolytic corrosion or the like by the liquid absorption 34. Therefore, the electricity storage device 200 can have high reliability.

3. Next, the power storage module according to this embodiment will be described with reference to the drawings. FIG. 14 is an exploded perspective view schematically showing the power storage module 300 according to the present embodiment. FIG. 15 is a diagram schematically illustrating the power storage module 300 according to the present embodiment, as viewed from the direction of the arrow XV in FIG.

  The power storage module 300 includes the power storage device according to the present invention. Below, the electrical storage module 300 which has the electrical storage device 100 is demonstrated as an electrical storage device which concerns on this invention.

  As shown in FIGS. 14 and 15, the power storage module 300 includes a plurality of power storage devices 100, a base member 310, a control board housing member 320, a cover member 330, a positive electrode module terminal 340, and a negative electrode module terminal. 350. For the sake of convenience, the control board housing member 320, the cover member 330, and the positive module terminal 340 are not shown in FIG. For convenience, FIG. 14 illustrates a state in which the number of power storage devices 100 is one less than that in FIG. 15.

  The plurality of power storage devices 100 are stacked along the Z-axis direction. The number of power storage devices 100 is not particularly limited, and can be changed as appropriate according to the application of the power storage module 300.

  As shown in FIG. 14, the plurality of power storage devices 100 are alternately stacked while being rotated 180 ° about the Z axis. That is, in plan view, when one power storage device 100 among the adjacent power storage devices 100 is rotated by 180 ° about the Z axis, the other power storage device 100 can overlap.

  The plurality of power storage devices 100 are electrically connected. More specifically, the plurality of power storage devices 100 are connected in series. That is, in the adjacent power storage device 100, the positive electrode terminal 20 of one power storage device 100 and the negative electrode terminal 22 of the other power storage device 100 are connected. The connected positive electrode terminal 20 and negative electrode terminal 22 are surrounded by a cover portion 57. Thereby, it can suppress that the terminals 20 and 22 contact a conductive member (not shown) and short-circuit, for example.

  As illustrated in FIG. 15, a notch portion 55 formed in the base portion 40 is disposed between the adjacent power storage devices 100. The notch 55 penetrates in the X-axis direction. The notch 55 can function as a vent hole and can improve the heat dissipation of the power storage module 300.

  Base member 310 is disposed below stacked power storage devices 100. The base member 310 can include a support portion 312 and a fixing portion 314. The support unit 312 can support the stacked power storage devices 100. More specifically, the support portion 312 includes a flat surface 313 and can stably support the power storage device 100 on the flat surface 313. The fixing portion 314 is provided around the support portion 312. A through-hole 315 is formed in the fixing portion 314, and the power storage module 300 can be fixed to a desired member (not shown) by passing a screw or the like (not shown) through the through-hole 315. Examples of the material of the base member 310 include aluminum, stainless steel, iron, and nickel-plated metal (for example, copper).

  The control board housing member 320 is provided on the stacked power storage device 100. Examples of the material of the control board housing member 320 include a resin such as plastic. On the lower side of the control board housing member 320, for example, a notch 322 is formed. The notch 322 penetrates in the X-axis direction. The shape and number of the notches 322 are not particularly limited. The notch 322 can function as a vent and can improve heat dissipation of the power storage module 300.

  A control board (not shown) is housed in the control board housing member 320. A control unit (not shown) made of an IC or the like is mounted on the control board. The control unit can detect the output voltage of the power storage cell 10 of each power storage device 100 and determine whether the output voltage is normal. The control unit may include a mechanism for recovering the output voltage when it is determined that the output voltage of the storage cell 10 is not normal.

  Here, FIG. 16 is a perspective view schematically showing the power storage module 300, as viewed from a direction different from FIG. For convenience, in FIG. 16, illustration of the control board housing member 320, the cover member 330, and the positive module terminal 340 is omitted. For convenience, FIG. 16 illustrates a state in which the number of power storage devices 100 is one less than that in FIG.

  The control unit is electrically connected to the terminals 20 and 22 via, for example, a connector 324 shown in FIG. More specifically, the connector 324 is joined to the connector terminal portion 326 exposed from the base body 40 (from the cell case 30). For example, the connector terminal portion 326 is formed integrally with a washer 26 (see FIG. 1) used when the terminals 20 and 22 are fixed.

  Here, FIG. 17 is a perspective view schematically showing the washer 26 in which the connector terminal portion 326 is integrally formed, and is a view seen from a direction different from FIG. The connector terminal portion 326 is connected to the end portion 26 a of the plate washer 26. The shape of the connector terminal 326 is not particularly limited as long as it can be connected to the connector 324.

  Since the connector terminal portion 326 is formed integrally with the washer 26, a new member is not required to form the connector terminal portion. Therefore, the number of parts of the power storage module 300 can be reduced. In FIG. 16, for convenience, the connector terminal portion 326 in a state before the connector 324 is joined is also illustrated.

  As shown in FIG. 15, the cover member 330 is formed on the control board housing member 320. The shape of the cover member 330 is not particularly limited as long as the stacked power storage devices 100 can be sandwiched together with the base member 310. Examples of the material of the cover member 330 include those listed as the materials of the base member 310 described above.

  In the cover member 330, the control board housing member 320, and the base member 310, for example, a through hole (not shown) penetrating in the Z-axis direction is formed. The through holes and the through holes 61 formed in the stacking fixing member 60 of the electricity storage device 100 are arranged so as to communicate with each other, and as shown in FIG. it can. Accordingly, the stacked power storage device 100 and control board housing member 320 can be sandwiched between the cover member 330 and the base member 310.

  The positive electrode module terminal 340 is electrically connected to, for example, the positive electrode terminal 20 of the power storage device 100 disposed at the uppermost position among the stacked power storage devices 100. The shape of the positive module terminal 340 is not particularly limited. Examples of the material of the positive electrode module terminal 340 include copper, aluminum, and metals obtained by performing nickel plating or gold plating on these. The positive module terminal 340 can be a positive electrode as the power storage module 300.

  The negative electrode module terminal 350 is electrically connected to, for example, the negative electrode terminal 22 of the electricity storage device 100 arranged at the lowermost position among the stacked electricity storage devices 100. The shape of the negative electrode module terminal 350 is not particularly limited. Examples of the material of the negative electrode module terminal 350 include copper, aluminum, and metals obtained by performing nickel plating or gold plating on these. The negative electrode module terminal 350 can be a negative electrode as the power storage module 300.

  Note that, depending on the size of the negative electrode module terminal 350, the negative electrode module terminal 350 is electrically connected to, for example, the negative electrode terminal 22 of the electricity storage device 100 disposed at the second lower position among the stacked electricity storage devices 100. May be. In this case, instead of the power storage device 100 disposed at the lowermost position, a cell case 30 that does not sandwich the power storage cell 10 may be disposed.

  In the illustrated example, the module terminal arranged at the upper side is the module terminal for positive electrode 340 and the module terminal arranged at the lower side is module terminal for negative electrode 350, but the module terminal arranged at the lower side is the module for positive electrode. It is good also as a terminal and it is good also considering the module terminal arrange | positioned upward as a module terminal for negative electrodes.

  The power storage module 300 according to the present embodiment has, for example, the following characteristics.

  According to the power storage module 300, a plurality of power storage devices 100 can be connected in series. Therefore, high energy can be achieved.

  According to the power storage module 300, the connected positive electrode terminal 20 and negative electrode terminal 22 can be surrounded by the cover portion 57 provided on the base body 40. Thereby, it can suppress that the terminals 20 and 22 contact a conductive member (not shown) and short-circuit, for example.

  According to the power storage module 300, the connector 324 electrically connected to the control unit can be joined to the connector terminal unit 326 formed integrally with the washer 26. Thereby, since a new member for forming the connector terminal portion is not required, the number of components of the power storage module 300 can be reduced. Therefore, the number of manufacturing steps can be reduced.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. The present invention can be appropriately combined with the above-described embodiments and modifications. Further, the present invention includes, for example, a configuration substantially the same as the configuration described in the embodiment (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

1 positive electrode, 1a positive electrode current collector, 1b positive electrode active material layer, 2 negative electrode, 2a negative electrode current collector,
2b negative electrode active material layer, 3 lithium electrode, 3a lithium electrode current collector, 3b lithium foil,
4 separator, 5 electrode laminate, 6 positive electrode lead, 7 negative electrode lead, 10 storage cell,
12 exterior body, 12a 1st laminate film, 12b 2nd laminate film,
13 body part, 14 outer peripheral part, 15 1st part, 16 2nd part, 17 long side,
18 short side, 20 positive terminal, 20a connection part, 22 negative terminal, 22a connection part,
24 through holes, 26 washers, 26a end, 27 through holes, 28 screws,
30 cell case, 32 discharge flow path, 34 liquid absorption, 40 base, 41 mounting portion,
42 terminal support part, 43 recessed part, 44 opening part, 46 terminal fixing part, 50 side wall part,
51a 1st side wall part, 51b 1st side wall part, 52a 2nd side wall part, 52b 2nd side wall part,
53 1st communication part, 54 2nd communication part, 55 Notch part, 56 Hook part,
57 cover part, 58 notch part, 60 fixing part for lamination, 61 through-hole, 70 lid,
71 Covering portion, 72 protruding portion, 73 small protruding portion, 74 bent portion,
74a 1st flow path formation part, 74b 2nd flow path formation part, 74c 3rd flow path formation part,
79 opening, 100 power storage device, 200 power storage device,
300 power storage module, 310 base member, 312 support part, 313 flat surface,
314 fixing part, 315 through hole, 320 control board housing member, 322 notch part,
324 connector, 326 connector terminal, 330 cover member,
340 module terminal for positive electrode, 350 module terminal for negative electrode, 360 screw

Claims (10)

A storage cell having a positive electrode, a negative electrode, and an outer package containing an electrolyte; and
A cell case sandwiching the storage cell;
Including
The exterior body has a main body part, and an outer peripheral part provided around the main body part,
The outer periphery is
A first portion sandwiched by the cell case;
A second part serving as a safety valve for releasing the gas in the exterior body;
Have
The cell case has a discharge channel for discharging the gas released from the second portion,
The electric discharge device, wherein the discharge channel extends along the outer peripheral portion. In claim 1,
The exterior body has a planar shape having a long side and a short side,
The electric discharge device, wherein the discharge channel extends along the long side. In claim 1 or 2,
The cell case has a base and a lid,
The base has a placement portion for placing the first portion;
The lid is
A covering portion covering the body portion;
A protrusion formed around the covering portion and protruding toward the base;
Have
The power storage device, wherein the first portion is sandwiched between the mounting portion and the protruding portion. In claim 3,
The electrical storage device in which the recessed part is formed in the said mounting part along the said 2nd part. In claim 4,
The base has a side wall provided around the mounting portion,
The lid has a bent portion provided on the outer periphery of the lid,
The side wall portion and the bent portion form the discharge flow path,
The electrical storage device in which the communication part which connects the said recessed part and the said discharge flow path is formed in the said side wall part. In any one of Claims 3 thru | or 5,
In the mounting portion, an opening is formed,
The main body is an electricity storage device disposed in the opening. In any one of Claims 1 thru | or 6,
The electricity storage device, wherein a liquid absorbing member that absorbs the electrolytic solution discharged from the second portion is provided in the discharge channel. In any one of Claims 1 thru | or 7,
The electricity storage device, wherein the electricity storage cell is a lithium ion capacitor. The electrical storage device according to any one of claims 1 to 8, wherein a plurality of the electrical storage devices are stacked,
The power storage module, wherein the plurality of power storage devices are electrically connected. In claim 9,
The storage cell is
A positive electrode terminal electrically connected to the positive electrode;
A negative electrode terminal electrically connected to the negative electrode,
The electrical storage module in which the said base is formed with the insulating cover part surrounding the said positive electrode terminal and the said negative electrode terminal.

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