JP5573319B2 - Power storage device and method for manufacturing power storage device - Google Patents

Description

  The present invention relates to a power storage device including a plurality of power generation elements and a method for manufacturing the power storage device.

  In the secondary battery described in Patent Document 1, a plurality of battery cases are arranged side by side in one direction, and the plurality of battery cases are integrally formed by welding. Each battery case accommodates a power generation element through an opening formed in the battery case, and the opening part of each battery case is sealed with a lid.

  In addition, a pair of end plates are disposed at both ends of the plurality of integrally configured battery cases, and a restraining band extending in the arrangement direction of the plurality of battery cases is connected to the pair of end plates. . By using the end plate and the restraining band, the restraining force is applied to the plurality of battery cases.

Japanese Patent Laid-Open No. 11-120963 (FIG. 2) JP 2002-008598 A JP 2007-103352 A JP 2001-023604 A JP 2003-164068 A

  As in Patent Document 1, in a structure that gives a restraining force to a rectangular battery case, in a plane orthogonal to the direction in which the restraining force is applied (in other words, the arrangement direction of a plurality of battery cases), The binding force acting on the power generation element in the battery case will vary. The variation in the binding force will be specifically described with reference to FIG.

  In FIG. 17, when the restraining force F is applied to the surface 101 of the rectangular battery case 100, the battery case 100 has surfaces 102 and 103 parallel to the direction in which the restraining force F acts. Although omitted in FIG. 17, the surfaces facing the surfaces 102 and 103 are also parallel to the direction in which the restraining force F acts.

  When the surfaces 102 and 103 are present in the battery case 100, a portion of the surface 101 connected to the surfaces 102 and 103 (for example, the corner portion P1) is not easily deformed. On the other hand, the part (for example, center part P2) away from the connection part with the surfaces 102 and 103 among the surfaces 101 is easily deformed. Therefore, even if a substantially uniform restraining force F is applied to the entire surface 101, the power generation elements housed in the battery case 100 receive different forces depending on the position of the surface 101. Thus, if the force acting on the power generation element varies according to the position in the surface 101, the charge / discharge reaction in the power generation element may also vary.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a power storage device that can suppress variation in the binding force acting on each power generation element depending on the position where the binding force acts in a structure that applies a binding force to a plurality of power generation elements. To provide an apparatus.

The first invention of the present application includes a plurality of power generation elements and a plurality of storage portions that respectively store the plurality of power generation elements, and the plurality of storage portions are arranged side by side in a predetermined arrangement direction (hereinafter simply referred to as an arrangement direction). And a case. The surface extending in the arrangement direction of each housing portion is formed in a shape that is convex toward the outside of the case, and the surfaces facing each other in the arrangement direction of each housing portion approach each other due to deformation by an external force. Is allowed to be displaced.

Among yield capacity portion, a surface facing the array direction can be in close contact with the power generating element housed in the housing portion.

When the case is made of metal, the surface extending in the arrangement direction of the housing portion is plastically deformed when receiving an external force, and the surfaces of the housing portion that are opposed to each other in the arrangement direction are displaced toward each other. Can do. In addition, it is possible to provide a restraining unit that applies a restraining force acting on the case in a direction sandwiching the case from both ends of the case in the arrangement direction.

The case is made of metal, and of the two power generation elements adjacent in the arrangement direction, the positive electrode tab attached to one power generation element and the negative electrode tab attached to the other power generation element are formed in the accommodating portion. The electrical storage device is electrically connected to the case and electrically connected to the positive electrode tab attached to one of the power generation elements. A negative electrode terminal fixed to the case, and an intermediate terminal fixed to the outer surface of the case. .

A second invention of the present application is a method for manufacturing a power storage device having a plurality of housing portions each housing a plurality of power generating elements, and including a case in which the plurality of housing portions are arranged in a predetermined arrangement direction. The step of accommodating each power generating element in each accommodating part of the case, and the binding force acting in the direction of sandwiching the case from both ends of the case in the arrangement direction is applied to the case to deform a part of each accommodating part Displacing the surfaces facing each other in the arrangement direction in the accommodating portions in a direction to bring them closer to each other. Here, a part of each accommodating portion is a surface that extends in the arrangement direction, and is a surface that is formed in a shape that is convex toward the outside of the case .

  Here, after the case is deformed, the lid that closes the plurality of accommodating portions can be fixed to the case. Moreover, electrolyte solution can be inject | poured into each said accommodating part using the opening part provided corresponding to each accommodating part among the lid | covers.

According to the present invention, a surface formed in a shape that extends in the arrangement direction and is convex toward the outside of the case among the respective accommodation portions is deformed, and is opposed in the arrangement direction among the respective accommodation portions. By displacing the surfaces in a direction approaching each other, a binding force can be applied to the power generation elements housed in the housing portions. Here, since the entire surfaces facing each other in the arrangement direction are easily displaced in a direction approaching each other, the restraining force applied to the power generation elements is prevented from varying according to the position in the surface facing in the arrangement direction. be able to.

It is an exploded view which shows the structure of the battery module which is Example 1 of this invention. 3 is a top view of a case in Embodiment 1. FIG. 2 is a longitudinal sectional view of a case in Embodiment 1. FIG. In Example 1, it is sectional drawing which shows the connection structure of a positive electrode terminal and a negative electrode terminal. In Example 1, it is a front view of a positive electrode terminal. In Example 1, it is a figure which shows the state which gave restraint force to the case which accommodated the electric power generation element. In Example 1, it is a figure explaining the deformation | transformation of the case by a restraint force. It is a figure which shows the structure which gives a restraining force to a case. It is a figure which shows the structure which gives a binding force to a case. 6 is a top view of a case in a modified example of Embodiment 1. FIG. FIG. 10 is a top view of a case in another modification example of the first embodiment. It is a longitudinal cross-sectional view of the battery module which is Example 2 of this invention. 6 is an external view of a battery module that is Embodiment 2. FIG. In Example 2, it is sectional drawing which shows the connection structure of a positive electrode terminal and a negative electrode terminal. 6 is a diagram illustrating a circuit configuration equivalent to a battery module that is Embodiment 2. FIG. It is a figure which shows the relationship between the electric potential of a positive electrode active material or a negative electrode active material, and the electric potential of the corrosion reaction of aluminum. It is a figure explaining the restraint force which acts on a battery case in the conventional structure.

  Examples of the present invention will be described below.

  A battery module (power storage device) that is Embodiment 1 of the present invention will be described. FIG. 1 is a diagram illustrating a configuration of a battery module according to the present embodiment. In FIG. 1, an X axis, a Y axis, and a Z axis are orthogonal to each other. In this embodiment, the Z axis is an axis corresponding to the vertical direction.

  The battery module 1 of the present embodiment has a case 10, and the case 10 has four accommodation spaces S for accommodating the power generation elements 20. Each accommodation space S is larger than the power generation element 20 so that the power generation element 20 can be inserted. Moreover, the accommodating part in this invention is comprised by the surface which forms each accommodation space S. FIG.

  The case 10 is made of a metal such as aluminum, and can be formed into the shape shown in FIG. 1 by, for example, impact molding. A lid 30 is fixed to the case 10, and the lid 30 closes a plurality of openings formed on the upper surface of the case 10 when fixed to the case 10.

  The lid 30 has an inlet 31 provided corresponding to each accommodation space S. The injection port 31 is used for injecting an electrolytic solution into the accommodation space S, and is filled with a lid (not shown) after the electrolytic solution is injected. The lid 30 has terminal through holes 32 and 33 for penetrating the positive terminal and the negative terminal of the battery module 1. The lid 30 can be formed of a metal such as aluminum, like the case 10.

  The four accommodation spaces S are arranged side by side in the X direction, and a partition portion 11 that forms a part of these accommodation spaces S is provided between two accommodation spaces S adjacent in the arrangement direction. Yes. The partition part 11 is formed with a tab connection port 11a. In the case 10, an insulating film is formed on the wall surface forming each accommodation space S, and the insulating film can be formed by, for example, anodizing.

  The power generation element 20 accommodated in each accommodation space S is an element that performs charge and discharge, and can be composed of a positive electrode element, a negative electrode element, and a separator disposed between the positive electrode element and the negative electrode element. Specifically, the power generation element 20 can be configured by configuring a stacked body in which a positive electrode element, a separator, and a negative electrode element are stacked in this order, and winding the stacked body. In the positive electrode element, a layer containing a positive electrode active material or the like is formed on the surface of the current collector. In the negative electrode element, a layer containing the negative electrode active material or the like is formed on the surface of the current collector. Is. The separator is impregnated with an electrolytic solution.

  At one end of the power generation element 20, a part 20a of the positive electrode element is exposed, and a positive electrode tab 21 is attached to the exposed part 20a. The positive electrode tab 21 can be formed of a metal such as aluminum. Further, a part 20b of the negative electrode element is exposed at the other end of the power generation element 20, and a negative electrode tab 22 is attached to the exposed part 20b. The negative electrode tab 22 can be formed of a metal such as copper. As the power generation element 20, a configuration used in a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be applied. An electric double layer capacitor may be used instead of the secondary battery.

  FIG. 2 is a diagram when the case 10 is viewed from above. As shown in FIG. 2, a plurality of bent portions 12 are provided on the side surface 10 a of the case 10. The side surface 10 a is a surface of the case 10 that extends in the arrangement direction (X direction) of the accommodation space S. Each bent portion 12 has a curvature in the XY plane, and is formed to be convex toward the outside of the case 10 (each storage space S). Each bent portion 12 is provided corresponding to each storage space S and constitutes a side surface of each storage space S.

  FIG. 3 is a cross-sectional view of the case 10 taken along the XZ plane. As shown in FIG. 3, a plurality of bent portions 13 are provided on the bottom surface 10 b of the case 10. The bottom surface 10b is a surface extending in the arrangement direction (X direction) of the accommodation space S. Each bent portion 13 has a curvature in the XZ plane, and is formed to be convex toward the outside of the case 10 (each storage space S). Each bent portion 13 is provided corresponding to each accommodation space S and constitutes the bottom surface of each accommodation space S.

  The four power generation elements 20 housed in the case 10 (four housing spaces S) are electrically connected in series. That is, of the two power generation elements 20 adjacent in the X direction, the positive electrode tab 21 in one power generation element 20 is connected to the negative electrode tab 22 in the other power generation element 20. Here, when the four power generation elements 20 are accommodated in the four accommodation spaces S, the two power generation elements 20 adjacent in the X direction are the positive electrode tab 21 of one power generation element 20 and the negative electrode tab 22 of the other power generation element 20. Are arranged adjacent to each other in the X direction.

  A connection structure of the positive electrode tab 21 and the negative electrode tab 22 will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a connection structure between the positive electrode tab 21 and the negative electrode tab 22. FIG. 5 is a front view of the positive electrode tab 21, and the positive electrode tab 21 and the negative electrode tab 22 connected to each other have the same shape.

  The positive electrode tab 21 has a protruding portion 21 a inserted into a tab connection port 11 a formed in the partition portion 11 of the case 10, and the protruding portion 21 a is separated from the tab connection port 11 a. Around the protrusion 21a, a groove 21b into which the O-ring 14 is incorporated is provided. The O-ring 14 is used for sealing between the positive electrode tab 21 and the partition portion 11.

  The negative electrode tab 22 has a protruding portion 22a that is inserted into the tab connection port 11a of the partition portion 11, and the protruding portion 22a is separated from the tab connection port 11a. The protruding portion 22a is bonded to the protruding portion 21a, and as a bonding method, for example, ultrasonic bonding can be used. Thereby, the two power generation elements 20 arranged side by side in the X direction are electrically connected in series. Around the protruding portion 22a, a groove portion 22b into which the O-ring 15 is incorporated is provided. The O-ring 15 is used for sealing between the negative electrode tab 22 and the partition portion 11.

  On the other hand, the positive electrode tab 21 of the power generation element 20 arranged at one end in the X direction (the innermost side in FIG. 1) is electrically and mechanically connected to a positive electrode terminal (not shown) fixed to the terminal through hole 32 of the lid 30. This positive electrode terminal becomes the positive electrode of the battery module 1. Further, the negative electrode tab 22 of the power generation element 20 arranged at the other end in the X direction (the frontmost side in FIG. 1) is electrically and mechanically connected to a negative electrode terminal (not shown) fixed to the terminal through hole 33 of the lid 30. This negative electrode terminal becomes the negative electrode of the battery module 1.

  A restraining force F is applied to the case 10 in which the power generation element 20 is accommodated in each accommodation space S, as shown in FIG. FIG. 6 is a view corresponding to FIG. 3 and a cross-sectional view of the case 10 in which the power generation element 20 is accommodated. The restraining force F is a force that sandwiches the case 10 in the arrangement direction (X direction) of the power generation elements 20.

  When a restraining force F is applied to the case 10, the bent portions 12 and 13 can be deformed (plastic deformation). That is, since each of the bent portions 12 and 13 has a region inclined with respect to the direction (X direction) in which the restraining force F acts, the bending portions 12 and 13 are easily deformed by receiving the restraining force F. For example, each bent portion 13 provided on the bottom surface 10b of the case 10 is deformed in the direction indicated by the arrow D1 in FIG.

  Focusing on each accommodation space S, as shown in FIG. 7, when a restraining force F is applied to each accommodation space S, the two partitioning portions 11 facing each other in the X direction are displaced in a direction approaching each other (direction of arrow D2). try to. Here, since the bottom surface of the accommodation space S is configured by the bent portion 13, the deformation of the bent portion 13 allows the two partition portions 11 to be displaced in a direction approaching each other. Further, a bent portion 12 is also provided on the side surface 10a of the case 10, and the bent portion 12 is also deformed to allow the two partition portions 11 to be displaced in a direction approaching each other.

  Thereby, the width (length in the X direction) W2 of the accommodation space S after applying the restraining force F becomes narrower than the width W1 of the accommodation space S before applying the restraining force F. In addition, in the accommodation space S located at both ends in the X direction, the partition wall 11 and the outer wall portion of the case 10 are displaced toward each other in the X direction, and the width of the accommodation space S is reduced.

  By reducing the width of the storage space S, the restraining force F can be applied to the power generation element 20 stored in the storage space S. In the present embodiment, since the bent portions 12 and 13 are provided for each accommodation space S, the restraining force F can be applied to the power generation element 20 accommodated in each accommodation space S.

  That is, the restraining force F can be applied to each of the four power generation elements 20 accommodated in the case 10 only by giving the restraining force F to the case 10. In addition, in this embodiment, by providing the bent portions 12 and 13, the entire surface of the partition portion 11 can be displaced in a direction approaching each other, and the restraining force F acting on the power generation element 20 is within the YZ plane. The variation can be suppressed. And by giving the substantially uniform restraining force F to each electric power generation element 20, it can suppress that variation arises in the charging / discharging reaction in the electric power generation element 20, and charging / discharging reaction is used using the whole electric power generation element 20. Can be performed efficiently.

  After applying the restraining force F to the case 10, the lid 30 is fixed to the upper surface of the case 10. As a method for fixing the lid 30, for example, welding can be used. And electrolyte solution is inject | poured from the inlet 31 of the lid | cover 30 with respect to each accommodation space S. FIG. After injecting the electrolytic solution, the injection port 31 is closed using a lid (not shown). Thereby, each accommodation space S will be in a sealed state. A valve for discharging the gas generated in the storage space S to the outside can be provided at the inlet 31.

  Next, a structure (restraining unit) that applies a restraining force F to the case 10 will be described with reference to FIGS. FIG. 8 shows a structure for applying a restraining force F to one battery module 1, and FIG. 9 shows a structure for giving a restraining force F to a plurality of battery modules 1.

  In the structure shown in FIG. 8, a pair of end plates 41, 42 are respectively arranged at both ends of the battery module 1, and a restraining band 43 extending in the X direction is connected to the pair of end plates 41, 42. . In the structure shown in FIG. 8, the restraining band 43 is disposed along the upper surface and the lower surface of the battery module 1. If the pair of end plates 41 and 42 are displaced in a direction approaching each other, the binding force F shown in FIGS. 6 and 7 can be applied to the battery module 1.

  In the structure shown in FIG. 9, a plurality of battery modules 1 are arranged side by side in the X direction, and a spacer 44 is arranged between two battery modules 1 arranged adjacent to each other. The spacer 44 has a protrusion 44 a, and a space can be formed on the surface of the battery module 1 by using the protrusion 44 a. This space portion can be used as a passage for allowing a heat exchange medium (gas or liquid) used for temperature adjustment of the battery module 1 to pass therethrough.

  In addition, a pair of end plates 41 and 42 are disposed at positions sandwiching the plurality of battery modules 1, and a restraining band 43 extending in the X direction is connected to the pair of end plates 41 and 42. In the structure shown in FIG. 9, the restraining band 43 is disposed along the upper and lower surfaces of the plurality of battery modules 1. When the pair of end plates are displaced in a direction approaching each other, the binding force F shown in FIGS. 6 and 7 can be applied to each battery module 1.

  The structure that applies the restraining force F to the case 10 is not limited to the structure illustrated in FIGS. 8 and 9, and the structure that allows the restraining force F illustrated in FIGS. 6 and 7 to act on the case 10. If it is. For example, the position where the restraint band 43 is arranged can be changed. On the other hand, the constraining structure shown in FIGS. 8 and 9 can be omitted. In other words, the restraining force F can be applied to the power generation elements 20 accommodated in the respective accommodation spaces S only by plastically deforming the case 10.

  In the present embodiment, four housing spaces S are provided for the case 10, but the present invention is not limited to this. That is, the number of the accommodation spaces S can be set as appropriate, and the present invention can be applied as long as the plurality of accommodation spaces S are arranged in one direction.

  Further, in this embodiment, the bent portions 12 and 13 having the shapes shown in FIGS. 2 and 3 are provided on the side surface 10a and the bottom surface 10b of the case 10, but the present invention is not limited to this. That is, it is only necessary that the side surface 10a and the bottom surface 10b of the case 10 are deformed to narrow the width of each storage space S. For example, the side surface 10a of the case 10 can be configured as shown in FIGS.

  FIG. 10 is a top view of a case 10 which is a modification of the present embodiment, and corresponds to FIG. Also in the configuration illustrated in FIG. 10, the side surface 10 a of the case 10 is provided with the bent portions 15 by the number of the accommodation spaces S, and each bent portion 15 is convex toward the outside of each accommodation space S. Is formed. Here, each bent portion 15 is composed of two planes 15a and 15b intersecting each other, and each plane 15a and 15b is inclined with respect to the X axis.

  FIG. 11 is a top view of a case 10 which is another modified example of the present embodiment, and corresponds to FIG. Also in the configuration shown in FIG. 11, the side surface 10 a of the case 10 is provided with the bent portions 16 by the number of the accommodation spaces S, and each bent portion 16 is convex toward the outside of each accommodation space S. Is formed. Here, each bending part 16 is comprised by the surface 16a inclined with respect to the X-axis, and the surface 16b orthogonal to the X-axis. The surface 16 b orthogonal to the X axis is formed integrally with the partition portion 11 of the case 10.

  10 and 11 show the structure on the side surface 10 a of the case 10, the same structure can be applied to the bottom surface 10 b of the case 10.

  Moreover, in the present Example, although the bending part 12 is formed so that it may become convex toward the outer side of the storage space S, it does not restrict to this. For example, the bent portion can be configured to be convex toward the inside of the accommodation space S. However, in this case, when the restraining force F is applied to the case 10, the bent portion is deformed toward the inside of the accommodation space S, so that it contacts the power generation element 20 accommodated in the accommodation space S. It is preferable not to do so.

  Furthermore, in this embodiment, the case 10 is made of metal, but it can also be made of other materials such as resin. Even when the case 10 is formed of resin, if the configuration described in the present embodiment is used, variation in the restraining force F in the YZ plane can be suppressed as compared with the conventional configuration shown in FIG. Can do.

  A battery module that is Embodiment 2 of the present invention will be described. FIG. 12 is a diagram illustrating the configuration of the battery module according to the present embodiment. In addition, about the member which has the same function as the member demonstrated in Example 1, the same code | symbol is used and detailed description is abbreviate | omitted.

  In the case 10 of the present embodiment, two accommodation spaces S are provided, and the power generation element 20 is accommodated in each accommodation space S. Further, similarly to the first embodiment, bent portions 12 and 13 are provided on the side surface 10a and the bottom surface 10b of the case 10. Further, the positive electrode tab 21 in one power generation element 20 and the negative electrode tab 22 in the other power generation element 20 are connected to each other via a tab connection port 11 a formed in the partition portion 11.

  As shown in FIG. 13, the negative electrode tab 22 in one power generation element 20 is electrically and mechanically connected to a negative electrode terminal 51 fixed to the lid 30. The positive electrode tab 21 in the other power generation element 20 is electrically and mechanically connected to a positive electrode terminal 52 fixed to the lid 30.

  The connection structure of the positive electrode tab 21 and the negative electrode tab 22 is substantially the same as the structure described in the first embodiment (see FIG. 4), but in this embodiment, as shown in FIG. 14, the positive electrode tab 21 and the negative electrode tab 22 are connected. Is in contact with the tab connection port 11 a of the partition 11. Specifically, the protruding portion 21a of the positive electrode tab 21 and the protruding portion 22a of the negative electrode tab 22 can be brought into contact with the tab connection port 11a by press fitting or the like. Thus, the positive electrode tab 21 and the negative electrode tab 22 are electrically connected to each other and also electrically connected to the case 10.

  An intermediate terminal 53 is fixed to the upper surface of the lid 30. Since the case 10 and the lid 30 are made of metal, if the intermediate terminal 53 is fixed to the lid 30, the intermediate terminal 53 is connected between the two power generation elements 20 that are electrically connected in series. Can do. FIG. 15 shows a circuit configuration equivalent to the battery module 1 of the present embodiment. In this embodiment, the intermediate terminal 53 is fixed to the upper surface of the lid 30, but the intermediate terminal 53 can also be fixed to the outer surface of the case 10.

  If the intermediate terminal 53 is provided, the voltage of each power generating element 20 can be measured. That is, in the circuit configuration shown in FIG. 15, the voltage between the intermediate terminal 53 and the negative terminal 51 is the voltage of the power generation element 20 located on the right side of FIG. 15, and the voltage between the intermediate terminal 53 and the positive terminal 52 is This is the voltage of the power generation element 20 located on the left side of FIG.

  Further, in the circuit configuration shown in FIG. 15, an equalization circuit can be connected to each power generation element 20 by using the intermediate terminal 53. The equalization circuit allows discharge of each power generation element 20 and equalizes voltages and the like in the plurality of power generation elements 20. Specifically, an equalization circuit can be connected to the intermediate terminal 53 and the positive terminal 52 and an equalization circuit can be connected to the intermediate terminal 53 and the negative terminal 51.

  In the battery module 1 of the present embodiment, as described with reference to FIG. 14, the positive electrode tab 21 and the negative electrode tab 22 are brought into contact with the case 10 (partition portion 11). Here, when the case 10 is made of aluminum and a negative electrode element of the power generation element 20 having a current collector formed with a carbon (negative electrode active material) layer is used, corrosion of the case 10 occurs. It becomes easy to do. This phenomenon will be described with reference to FIG.

FIG. 16 is a diagram showing the potentials of the positive electrode active material and the negative electrode active material in the power generation element 20, and is based on the potential of metallic lithium. Since the potential of the carbon negative electrode is lower than the potential of the corrosion reaction of aluminum, when carbon is used as the negative electrode active material, the case 10 made of aluminum is easily corroded. The corrosion reaction of aluminum is expressed as “Li ⁺ + Al + e ⁻ → LiAl”, and when LiAl is generated, the strength is greatly reduced.

  On the other hand, since lithium titanate is higher in potential than the corrosion reaction of aluminum, if lithium titanate is used as the negative electrode active material, the occurrence of the corrosion reaction of aluminum can be prevented. Further, when lithium titanate is used as the negative electrode active material, the current collector of the negative electrode element can be formed of aluminum. In this case, the current collector in the positive electrode element and the negative electrode element can be formed of aluminum, and the case 10 can be formed of aluminum.

  When carbon is used as the negative electrode active material, a cell voltage of 3.6 [V] can be obtained. However, when lithium titanate is used as the negative electrode active material, the cell voltage is 2.2 [V]. On the other hand, the negative electrode active material is not limited to lithium titanate. If a material having a higher potential than the corrosion reaction of aluminum is selected as the negative electrode active material, the corrosion reaction of aluminum can be prevented.

  On the other hand, Patent Document 1 describes a structure that gives a binding force to a plurality of battery cases arranged side by side in one direction, and Patent Document 2 has a configuration in which uneven portions are provided on the side surface and bottom surface of a case. Is described. Here, the configurations described in Patent Documents 1 and 2 cannot be combined. That is, in the technique described in Patent Document 2, since the concave and convex portions are provided in order to widen the interval between two side walls facing each other in the case according to the expansion of the electrode, such a case is provided. It is impossible to combine a structure that prevents the deformation of the structure (the structure described in Patent Document 1).

DESCRIPTION OF SYMBOLS 1: Battery module (electric storage apparatus) 10: Case 10a: Side surface 10b: Bottom surface 11: Partition part 11a: Terminal connection port 12, 13: Bending part 14, 15: O-ring 20: Power generation element 20a: Positive electrode element 20b: Negative electrode element 21: Positive terminal 22: Negative terminal 30: Lid 31: Injection port 32, 33: Terminal through hole 41, 42: End plate (part of restraint unit)
43: Restraint band (part of restraint unit)
44: Spacer

Claims (8)

A plurality of power generation elements;
A plurality of housing portions each housing the plurality of power generating elements, and the plurality of housing portions arranged in a predetermined arrangement direction, and
The surface extending in the arrangement direction of the plurality of storage portions among the storage portions is formed in a shape that is entirely convex toward the outside of the case, and by deformation due to external force, A power storage device characterized by allowing displacement of opposing surfaces in an arrangement direction in a direction approaching each other. Among the receiving portion, a surface that faces in the arrangement direction, the power storage device according to claim 1, characterized in that closely to the power generating element housed in the housing portion. The case is made of metal,
The surface extending in the arrangement direction of the accommodating portion is plastically deformed when receiving an external force, and is displaced in a direction in which the opposing surfaces of the accommodating portion are brought closer to each other in the arrangement direction. The power storage device according to claim 1 or 2 . Power storage device according to either end of the case, in any one of claims 1 3, characterized in that it comprises a restraining unit that gives a constraining force acting in a direction to sandwich the case to the case in the arrangement direction. The case is made of metal,
Of the two power generation elements adjacent in the arrangement direction, a positive electrode tab attached to one of the power generation elements and a negative electrode tab attached to the other power generation element are openings formed in the housing portion. Is electrically and mechanically connected to the case, and is electrically connected to the case,
A positive electrode terminal electrically connected to a positive electrode tab attached to the one power generation element and fixed to the case;
A negative electrode terminal electrically connected to a negative electrode tab attached to the other power generation element, and fixed to the case;
Power storage device according to any one of the four claims 1, characterized in that it comprises a intermediate terminal secured to the outer surface of the case. A method of manufacturing a power storage device comprising a plurality of housing portions each housing a plurality of power generating elements, and comprising a case in which the plurality of housing portions are arranged in a predetermined arrangement direction,
Accommodating each of the power generation elements in each of the accommodating portions of the case;
By applying a restraining force acting in a direction sandwiching the case from both ends of the case in the arrangement direction, a part of each of the storage parts is deformed, and the arrangement direction of the storage parts. Displacing the opposing surfaces in a direction to approach each other, and
Wherein a portion of each housing portion, a surface extending in the arrangement direction, a manufacturing method of a power storage device across toward the outside of said case and said Rukoto is formed in a shape which is convex. The method for manufacturing a power storage device according to claim 6 , wherein after the case is deformed, a lid that closes the plurality of accommodating portions is fixed to the case. The method for manufacturing a power storage device according to claim 7 , wherein an electrolyte is injected into each of the housing portions using an opening provided corresponding to each of the housing portions of the lid.

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