JP2019186021A - Power storage device and manufacturing method of power storage device - Google Patents

Abstract

To provide a power storage device capable of improving vibration resistance, and to provide a manufacturing method of a power storage device.SOLUTION: A power storage device 1 includes a cell stack including multiple power storage cells 7 laminated via a positive electrode collector plate 15 and a negative electrode collector plate 16 alternately, a positive electrode bus bar 4 extending in the lamination direction, and joined to the positive electrode collector plate 15, a negative electrode bus bar 5 extending in the lamination direction, and joined to the negative electrode collector plate 16, a cover member 6 extending in the lamination direction, and provided on the top face of a cell stack 2. Each of the multiple power storage cells 7 has multiple bipolar electrodes, and a holding member 9 for holding the multiple bipolar electrodes, the cover member 6 has a recess 61 for locking the holding member 9 in the width direction, and the holding member 9 has a protrusion 91 facing the recess 61 in the width direction.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a power storage device and a method for manufacturing the power storage device.

  As a conventional power storage device, for example, a battery unit described in Patent Document 1 is known. The battery unit described in Patent Document 1 includes a plurality of bipolar batteries and current collectors arranged on both sides of the bipolar battery so as to sandwich the bipolar batteries. The current collector disposed on one side of the bipolar battery functions as a positive electrode current collecting electrode and is electrically connected to a positive electrode connection conductor extending in the stacking direction of the bipolar battery. The current collector disposed on the other side of the bipolar battery functions as a negative electrode current collecting electrode, and is electrically connected to a negative electrode connection conductor extending in the stacking direction of the bipolar battery.

JP 2009-117105 A

  In the battery unit (power storage device) described in Patent Document 1, each connection conductor (bus bar) is connected to the current collector by welding or the like. When the power storage device is mounted on a vehicle or the like, a force may be applied to each power storage cell in a direction intersecting with the stacking direction of the bipolar batteries (power storage cells) due to vibration. For example, when the magnitude of the force applied to one storage cell is different from the magnitude of the force applied to another storage cell, a shear stress is applied to the junction between the bus bar and the current collector, and the current collector is removed from the bus bar. There is a risk of peeling.

  The objective of this invention is providing the electrical storage apparatus which can improve vibration resistance, and the manufacturing method of an electrical storage apparatus.

  A power storage device according to one aspect of the present invention includes a cell stack including a plurality of power storage cells stacked along a first direction alternately via a positive electrode current collector plate and a negative electrode current collector plate, and along the first direction. A positive electrode bus bar extending and bonded to the positive electrode current collector plate in the second direction intersecting the first direction, and a negative electrode bus bar extending along the first direction and bonded to the negative electrode current collector plate in the second direction And a cover member extending along the first direction and provided on the top surface in the second direction of the cell stack. Each of the plurality of power storage cells includes a plurality of electrodes stacked along the first direction and a holding member that holds the plurality of electrodes. The cover member has a locking portion for locking the holding member in a third direction intersecting the first direction and the second direction. The holding member has a locked portion that faces the locking portion in the third direction.

  In this power storage device, the locking portion of the cover member faces the locked portion of the holding member in the third direction. For this reason, even if force is applied to each power storage cell along the third direction due to vibration, the locked portion comes into contact with the locking portion, so that the movement of the holding member in the third direction locks the cover member. Regulated by the department. Thereby, it is suppressed that each electrical storage cell moves to a 3rd direction with respect to a cover member separately. That is, when the plurality of power storage cells are integrally moved in the third direction, the positive electrode current collecting plate and the negative electrode current collecting plate interposed between the power storage cells can be integrally moved in the third direction. Therefore, the shear stress applied along the third direction at the joint between the positive electrode bus bar and the positive electrode current collector plate can be reduced. Similarly, the shear stress applied along the third direction at the junction between the negative electrode bus bar and the negative electrode current collector plate can be reduced. As a result, the vibration resistance of the power storage device can be improved.

  The holding member may have a convex portion that protrudes toward the cover member along the second direction. The cover member may be provided with a recess that fits into the protrusion. The locking part may be a concave part, and the locked part may be a convex part. In this case, since the convex part of the holding member and the concave part of the cover member are fitted to each other, it is possible to more reliably suppress the movement of each storage cell in the third direction with respect to the cover member.

  The cover member may have a convex portion that protrudes toward the holding member along the second direction. The holding member may be provided with a concave portion that fits with the convex portion. The locking part may be a convex part, and the locked part may be a concave part. In this case, since the convex part of the cover member and the concave part of the holding member are fitted, it is possible to more reliably suppress the movement of each storage cell in the third direction with respect to the cover member.

  The cover member may be provided with a through hole that penetrates the cover member in the second direction. The holding member may protrude toward the cover member along the second direction, and may have a protrusion that is inserted through the through hole. The locking portion may be an inner peripheral surface that defines the through hole, and the locked portion may be a protruding portion. In this case, since the protruding portion of the holding member is inserted through the through hole of the cover member, the protruding portion can contact the inner peripheral surface of the through hole in the third direction. For this reason, the movement of the holding member in the third direction is restricted by the through hole of the cover member. Thereby, it can suppress more reliably that each electrical storage cell moves to a 3rd direction with respect to a cover member.

  The cover member may have an end surface in the third direction. The holding member may have a protruding portion that protrudes along the second direction and faces the end surface in the third direction. The locking part may be an end face, and the locked part may be a protruding part. In this case, the protrusion of the holding member abuts on the end surface of the cover member, so that the movement of the holding member in the third direction is restricted by the end surface of the cover member. Thereby, it can suppress more reliably that each electrical storage cell moves to a 3rd direction with respect to a cover member.

  The cover member may be provided between the positive electrode bus bar and the negative electrode bus bar. The cover member may be made of an insulating material. In this case, the possibility that the positive electrode bus bar and the negative electrode bus bar are short-circuited can be reduced.

  The cover member may have a first portion provided along the top surface in the second direction of the holding member and a second portion provided along the side surface in the third direction of the holding member. The locking part may be the second part. The locked portion may be a side surface. In this case, the movement of the holding member in the third direction is restricted by the second portion of the cover member by the side surface of the holding member coming into contact with the second portion of the cover member. Thereby, it can suppress more reliably that each electrical storage cell moves to a 3rd direction with respect to a cover member.

  A method of manufacturing a power storage device according to another aspect of the present invention includes a step of forming a cell stack by stacking a plurality of power storage cells along a first direction through alternately positive and negative current collector plates. And a step of arranging a pair of end plates at both ends in the first direction of the cell stack, and a cover member extending along the first direction on the top surface in the second direction intersecting the first direction of the cell stack Attaching the positive electrode bus bar and the negative electrode bus bar extending along the first direction, joining the positive electrode bus bar and the positive electrode current collector plate, and connecting the negative electrode bus bar and the negative electrode current collector plate Bonding. Each of the plurality of power storage cells includes a plurality of electrodes stacked along the first direction and a holding member that holds the plurality of electrodes. The cover member has a locking portion for locking the holding member in a third direction intersecting the first direction and the second direction. The holding member has a locked portion that faces the locking portion in the third direction. When the cover member is attached, the positions of the plurality of storage cells in the third direction are aligned by bringing the locking portion and the locked portion into contact with each other in the third direction.

  In the power storage device manufactured by this manufacturing method, the locking portion of the cover member faces the locked portion of the holding member in the third direction. For this reason, even if force is applied to each power storage cell along the third direction due to vibration, the locked portion comes into contact with the locking portion, so that the movement of the holding member in the third direction locks the cover member. Regulated by the department. Thereby, it is suppressed that each electrical storage cell moves to a 3rd direction with respect to a cover member separately. That is, when the plurality of power storage cells are integrally moved in the third direction, the positive electrode current collecting plate and the negative electrode current collecting plate interposed between the power storage cells can be integrally moved in the third direction. Therefore, the shear stress applied along the third direction at the joint between the positive electrode bus bar and the positive electrode current collector plate can be reduced. Similarly, the shear stress applied along the third direction at the junction between the negative electrode bus bar and the negative electrode current collector plate can be reduced. As a result, the vibration resistance of the power storage device can be improved.

  According to the present invention, the vibration resistance of the power storage device can be improved.

FIG. 1 is a schematic perspective view showing a power storage device according to an embodiment. FIG. 2 is a perspective view showing the electricity storage cell shown in FIG. 1 together with a positive electrode current collector plate and a negative electrode current collector plate. 3 is a cross-sectional view of the electricity storage cell shown in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 5 is a cross-sectional view taken along line VV in FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is a process diagram showing a method of manufacturing the power storage device shown in FIG. FIG. 8 is a cross-sectional view of the power storage device according to the first modification. FIG. 9 is a cross-sectional view of a power storage device according to a second modification. FIG. 10 is a cross-sectional view of a power storage device according to a third modification. FIG. 11 is a cross-sectional view of a power storage device according to a fourth modification.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and redundant descriptions are omitted. In the drawing, an XYZ orthogonal coordinate system is shown as necessary.

  FIG. 1 is a schematic perspective view showing a power storage device according to an embodiment. FIG. 2 is a perspective view showing the electricity storage cell shown in FIG. 1 together with a positive electrode current collector plate and a negative electrode current collector plate. 3 is a cross-sectional view of the electricity storage cell shown in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 5 is a cross-sectional view taken along line VV in FIG. The power storage device 1 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid cars, and electric cars. The power storage device 1 includes a cell stack 2, a pair of end plates 3, a positive electrode bus bar 4, a negative electrode bus bar 5, and a cover member 6.

  The cell stack 2 is configured by stacking a plurality of power storage cells 7. The cell stack 2 is an aggregate of about 100 storage cells 7, for example. In the following description, the stacking direction of the storage cells 7 is the X-axis direction (first direction), the width direction of the storage cells 7 is the Y-axis direction (third direction), and the height direction of the storage cells 7 is the Z-axis direction. (Second direction). In the following description, the stacking direction of the storage cells 7 is simply expressed as “stacking direction”, the width direction of the storage cells 7 is simply expressed as “width direction”, and the height direction of the storage cells 7 is simply expressed as “height direction”. .

  The storage cell 7 is a single battery having a flat, substantially rectangular parallelepiped shape. The storage cell 7 may be a secondary battery such as a nickel hydride secondary battery or a lithium ion secondary battery, or may be an electric double layer capacitor. The storage cell 7 may be an all-solid battery. In this embodiment, the case where the electrical storage cell 7 is a bipolar type lithium ion secondary battery is illustrated.

  As shown in FIGS. 2 and 3, the power storage cell 7 includes an electrode stack 8 and a holding member 9. The electrode laminate 8 has a structure in which a plurality of bipolar electrodes 10 (a plurality of electrodes) are laminated via a separator 11. The plurality of bipolar electrodes 10 are stacked along the stacking direction. The bipolar electrode 10 has a current collector 12, a positive electrode layer 13 formed on one surface of the current collector 12, and a negative electrode layer 14 formed on the other surface of the current collector 12. .

  The current collector 12 is a sheet-like conductive member having a substantially rectangular shape. The current collector 12 is, for example, a metal foil or an alloy foil. Examples of the metal foil include copper foil, aluminum foil, titanium foil, and nickel foil. When the current collector 12 is a metal foil, an aluminum foil may be used as the current collector 12 from the viewpoint of securing mechanical strength. Examples of the alloy foil include a stainless steel foil or an alloy foil of the above metal. When the current collector 12 is a metal foil other than the alloy foil and the aluminum foil, the surface of the current collector 12 may be coated with aluminum.

  The positive electrode layer 13 includes a positive electrode active material and an electrolyte. The positive electrode active material is, for example, a composite oxide, metallic lithium or sulfur. The composition of the composite oxide includes, for example, at least one of manganese, titanium, nickel, cobalt, and aluminum and lithium. The electrolyte is, for example, a solid electrolyte, a solid polymer electrolyte, or a gel electrolyte. The solid electrolyte includes zirconia or β-alumina. The solid polymer electrolyte includes, for example, an alkylene oxide polymer compound such as polyethylene oxide (PEO) and polypropylene oxide (PPO), or a copolymer thereof. A gel electrolyte is an electrolyte that does not exhibit fluidity completely or exhibits fluidity almost completely. For example, the viscosity of the gel electrolyte at 20 ° C. is 0.1 Pa · S or more.

When the positive electrode layer 13 includes a solid polymer electrolyte, the positive electrode layer 13 is, for example, at least one of a supporting salt for increasing ionic conductivity, a conductive assistant for increasing electron conductivity, a viscosity adjusting solvent, and a polymerization initiator. Including The supporting salt is, for example, a lithium salt from the viewpoint of being easily soluble in the alkylene oxide polymer compound. The lithium salt is, for example, LiBF ₄ , LiPF ₆ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , or a mixture thereof. The conductive auxiliary agent is, for example, acetylene black, carbon black, or graphite. The viscosity adjusting solvent is, for example, N-methyl-2-pyrrolidone (NMP). Examples of the polymerization initiator include azobisisobutyronitrile (AIBN).

The negative electrode layer 14 includes a negative electrode active material and an electrolyte. Examples of the negative electrode active material include graphite, highly oriented graphite, mesocarbon microbeads, carbon such as hard carbon or soft carbon, alkali metals such as lithium or sodium, metal compounds, SiO _x (0.5 ≦ x ≦ 1.5 ) And the like, or boron-added carbon. The electrolyte of the negative electrode layer 14 is the same as the electrolyte contained in the positive electrode layer 13, for example.

  The separator 11 is a layered member that separates the bipolar electrodes 10 adjacent to each other, and has a substantially rectangular shape. The separator 11 is composed of an electrolyte contained in the positive electrode layer 13 and the negative electrode layer 14. The separator 11 may be a porous film that can be filled with an electrolyte. When the separator 11 is formed of a solid electrolyte, the separator 11 may have a substantially rectangular plate shape.

  Current collectors 12 are respectively provided at both ends of the electrode stack 8 in the stacking direction. Only the positive electrode layer 13 is formed on the current collector 12 positioned at one end of the electrode laminate 8 (the right end in FIG. 3), and this current collector 12 functions as the positive electrode terminal of the storage cell 7. . Only the negative electrode layer 14 is formed on the current collector 12 positioned at the other end of the electrode laminate 8 (the left end in FIG. 3). The current collector 12 functions as a negative electrode terminal of the storage cell 7. To do.

  The holding member 9 is a member that holds the electrode stack 8 (a plurality of bipolar electrodes 10). The holding member 9 has a rectangular frame shape surrounding both side surfaces, top surfaces, and bottom surfaces of the electrode laminate 8 in the width direction. The holding member 9 is made of, for example, a resin having insulating properties and heat resistance. Examples of the resin forming the holding member 9 include polyimide, polypropylene (PP), polyphenylene sulfide (PPS), and nylon 66 (PA66). The holding member 9 has a function of sealing the bipolar electrode 10 and preventing a short circuit between the bipolar electrodes 10.

  The plurality of power storage cells 7 are stacked via the positive electrode current collector plates 15 and the negative electrode current collector plates 16 alternately. The positive electrode current collector plate 15 and the negative electrode current collector plate 16 are metal plates having a rectangular shape substantially the same shape as the main surface of the storage cell 7. The main surface of the storage cell 7 is a pair of surfaces intersecting the stacking direction of the electrode stack 8, specifically, the outer surface of the current collector 12 positioned at both ends of the electrode stack 8 in the stacking direction. . The positive electrode current collector plate 15 and the negative electrode current collector plate 16 are made of, for example, the same metal material as that of the current collector 12. The positive electrode current collector plate 15 and the negative electrode current collector plate 16 are disposed so as to sandwich the storage cell 7 in the stacking direction. The positive electrode current collector plate 15 is in contact with the outer surface of the current collector 12 that functions as the positive electrode terminal of the storage cell 7. The negative electrode current collector plate 16 is in contact with the outer surface of the current collector 12 that functions as the negative electrode terminal of the storage cell 7.

  The positive electrode current collector plate 15 includes a main body portion 15a having a rectangular shape in plan view, and a positive electrode tab 15b integrated with the main body portion 15a. The main body portion 15a contacts the current collector 12 that functions as a positive electrode terminal. The positive electrode tab 15 b is joined to the positive electrode bus bar 4. The positive electrode tab 15b protrudes in the height direction with respect to the electrode laminate 8 on one side in the width direction. The tip of the positive electrode tab 15 b is bent outward from the storage cell 7. The bent portion of the positive electrode tab 15b of each positive electrode current collector plate 15 is aligned facing one side in the stacking direction. And the positive electrode bus-bar 4 is joined with the bending part of the positive electrode tab 15b of each positive electrode current collecting plate 15 by welding etc. (refer FIG. 4). The positive electrode current collector plate 15 and the positive electrode bus bar 4 are joined by a welded portion W1. In addition, the width | variety of the positive electrode tab 15b is smaller than the half of the width | variety of the positive electrode current collecting plate 15, and the width | variety of the positive electrode tab 15b of each positive electrode current collecting plate 15 is mutually equal.

  The negative electrode current collector plate 16 has a main body portion 16a having a rectangular shape in plan view, and a negative electrode tab 16b integrated with the main body portion 16a. The main body portion 16a contacts the current collector 12 functioning as a negative electrode terminal. The negative electrode tab 16 b is joined to the negative electrode bus bar 5. The negative electrode tab 16b protrudes in the height direction with respect to the electrode laminate 8 on the other side in the width direction. The negative electrode tab 16b protrudes on the same side as the positive electrode tab 15b in the height direction. The tip of the negative electrode tab 16 b is bent outward from the storage cell 7. The bending direction of the negative electrode tab 16b is opposite to the bending direction of the positive electrode tab 15b. The bent portion of the negative electrode tab 16b of each negative electrode current collector plate 16 is aligned facing the other side in the stacking direction. And the negative electrode bus-bar 5 is joined to the bending part of the negative electrode tab 16b of each negative electrode current collecting plate 16 by welding etc. (refer FIG. 5). The negative electrode current collector plate 16 and the negative electrode bus bar 5 are joined by a welded portion W2. The width of the negative electrode tab 16b is smaller than half the width of the negative electrode current collector plate 16, and the width of the negative electrode tab 16b of each negative electrode current collector plate 16 is equal to each other. The negative electrode tab 16b is separated from the positive electrode tab 15b in the width direction.

  The end plate 3 is a restraining member that regulates the displacement of the storage cell 7 in the stacking direction. The end plates 3 are arranged on both sides of the cell stack 2 in the stacking direction. The end plate 3 has an L shape in side view. The end plate 3 is made of, for example, a metal or an alloy. The end plates 3 are connected to each other by a cover member 6, and a restraining load along the stacking direction is applied to the cell stack 2 via the end plate 3. Each end plate 3 may be connected with fastening members, such as a volt | bolt and a nut. In this case, a binding load along the stacking direction is applied to the cell stack 2 via the end plate 3 by the tightening force of the fastening member.

  Insulation buffer members 17 are respectively disposed between the storage cells 7 and the end plates 3 positioned at both ends of the cell stack 2 in the stacking direction. The insulating buffer member 17 is a member having a function of absorbing expansion of the storage cell 7. The insulating buffer member 17 has, for example, a rectangular parallelepiped shape having the same area as the main surface of the storage cell 7 when viewed from the stacking direction. Examples of a material for forming the insulating buffer member 17 include PP, PPS, and PA66.

  Each of the positive electrode bus bar 4 and the negative electrode bus bar 5 extends along the stacking direction, as shown in FIG. The positive electrode bus bar 4 and the negative electrode bus bar 5 are arranged side by side in the width direction on the same side in the height direction with respect to the cell stack 2. Specifically, the positive electrode bus bar 4 is disposed on one side in the width direction on the top surface of the cell stack 2. The negative electrode bus bar 5 is arranged on the other side in the width direction on the top surface of the cell stack 2 so as to be separated from the positive electrode bus bar 4. The positive electrode bus bar 4 is joined to each positive electrode current collector plate 15 and is electrically connected to each positive electrode current collector plate 15. The negative electrode bus bar 5 is joined to each negative electrode current collector plate 16 and is electrically connected to each negative electrode current collector plate 16.

  The positive electrode bus bar 4 and the negative electrode bus bar 5 have a rectangular plate shape, for example. The forming material of the positive electrode bus bar 4 and the negative electrode bus bar 5 may be, for example, a metal such as copper, aluminum, titanium, or nickel, or may be stainless steel or an alloy of the above-described metals.

  An extraction terminal for connecting the cell stack 2 to an external device may be connected to one end in the longitudinal direction of the positive electrode bus bar 4. An extraction terminal for connecting the cell stack 2 to an external device may be connected to one end of the negative electrode bus bar 5 in the longitudinal direction.

  The cover member 6 is a member for defining a position in the height direction. The cover member 6 extends along the stacking direction. The cover member 6 is made of, for example, a metal or an alloy. The cover member 6 is disposed between the positive electrode bus bar 4 and the negative electrode bus bar 5 in a state of being separated from the positive electrode bus bar 4 and the negative electrode bus bar 5 on the top surface of the cell stack 2. The cover member 6 has a main body portion 6a extending in the stacking direction and a pair of claw portions 6b provided at both ends in the longitudinal direction of the main body portion 6a. The claw portion 6 b is fixed to the outer surface of the end plate 3 by the fastening member E. Thereby, the cover member 6 is locked to the cell stack 2, and a restraining load along the stacking direction is applied to the cell stack 2 via the pair of end plates 3. Note that the cover member 6 regulates the positional deviation of the storage cell 7 in the height direction and also regulates the positional deviation of the storage cell 7 in the width direction.

  Next, with reference to FIG. 6 further, the regulation of displacement of the storage cell 7 by the cover member 6 will be described. 6 is a sectional view taken along line VI-VI in FIG.

  As shown in FIG. 6, the holding member 9 includes a convex portion 91 that protrudes toward the cover member 6 along the height direction. The convex portion 91 is provided on the top surface 9 a of the holding member 9 and is located at the approximate center in the width direction. The convex portion 91 has a top surface 91a that intersects the height direction, and a side surface 91b and a side surface 91c that intersect the width direction.

  A recess 61 is provided on the bottom surface 6 c of the cover member 6. The recess 61 is a groove extending along the stacking direction. The recess 61 extends, for example, from one claw portion 6b to the other claw portion 6b. The recess 61 is located at the approximate center of the cover member 6 in the width direction. The concave portion 61 has a shape that fits with the convex portion 91 of the holding member 9. The recess 61 has a bottom surface 61a that intersects the height direction and side surfaces 61b and 61c that intersect the width direction. In the power storage device 1, the convex portion 91 is fitted in the concave portion 61. That is, the side surface 91b is opposed to and in contact with the side surface 61b in the width direction. The side surface 91c faces and contacts the side surface 61c in the width direction.

  With this configuration, the holding member 9 is suppressed from moving in the width direction. That is, the concave portion 61 functions as a locking portion that locks the holding member 9 in the width direction, and the convex portion 91 functions as a locked portion that faces the concave portion 61 in the width direction. Thereby, since each electrical storage cell 7 is suppressed from moving in the width direction with respect to the cover member 6, the relative position of the electrical storage cell 7 with respect to the cover member 6 is defined in the width direction.

  As described above, in the power storage device 1, the concave portion 61 of the cover member 6 and the convex portion 91 of the holding member 9 are fitted. For this reason, even if force is applied to each storage cell 7 along the width direction by vibration, the side surface 91b of the convex portion 91 abuts on the side surface 61b of the concave portion 61 in the width direction, and the side surface 91c of the convex portion 91 is in the width direction. , The movement of the holding member 9 in the width direction is restricted by the concave portion 61 of the cover member 6. Thereby, it is suppressed that each electrical storage cell 7 moves to the width direction with respect to the cover member 6 separately. That is, since the plurality of power storage cells 7 move together in the width direction, the positive current collector plate 15 and the negative current collector plate 16 interposed between the power storage cells 7 can also move in the width direction. Thereby, the shearing stress applied along the width direction to the welded portion W1 between the positive electrode bus bar 4 and the positive electrode current collector plate 15 can be reduced. Similarly, the shear stress applied along the width direction to the welded portion W2 between the negative electrode bus bar 5 and the negative electrode current collector plate 16 can be reduced. As a result, the vibration resistance of the power storage device 1 can be improved.

  Note that the side surface 91b may be in contact with the side surface 61b in the width direction or may be separated. Similarly, the side surface 91c may be in contact with the side surface 61c in the width direction or may be separated. In any case, when the holding member 9 is about to move in the width direction, at least one of the side surface 91b and the side surface 91c abuts against the opposing side surface (the side surface 61b or the side surface 61c). Thereby, it is suppressed that the holding member 9 moves in the width direction.

  Next, with reference to FIG. 7, the manufacturing method of the electrical storage apparatus 1 is demonstrated. FIG. 7 is a process diagram showing a method of manufacturing the power storage device shown in FIG.

  As shown in FIG. 7, first, in step S01, the cell stack 2 is formed. Specifically, a plurality of power storage cells 7 are stacked along one direction with the positive electrode current collecting plate 15 and the negative electrode current collecting plate 16 being alternately arranged. Thereby, the cell stack 2 is formed.

  Subsequently, in step S02, a pair of end plates 3 are arranged. Specifically, a pair of end plates 3 are disposed on both ends of the cell stack 2 in the stacking direction via insulating buffer members 17.

  Subsequently, the cover member 6 is attached to the cell stack 2 in step S03. Specifically, the main body 6a of the cover member 6 is disposed on the top surface of the cell stack 2 along the stacking direction. At this time, the convex portions 91 of the holding members 9 are fitted into the concave portions 61 of the cover member 6. That is, the side surface 61b of the concave portion 61 and the side surface 91b of each convex portion 91 abut, and the side surface 61c of the concave portion 61 and the side surface 91c of each convex portion 91 abut. Thereby, the position in the width direction of the some electrical storage cell 7 is arrange | equalized. The claw portion 6b is fixed to the outer surface of the end plate 3 by the fastening member E. As a result, a binding load along the stacking direction is applied to the cell stack 2 via the pair of end plates 3.

  Subsequently, in step S04, the positive electrode bus bar 4 and the negative electrode bus bar 5 are arranged. Specifically, the positive electrode bus bar 4 and the negative electrode bus bar 5 are arranged on the top surface of the cell stack 2 so as to sandwich the cover member 6 in the width direction. More specifically, the positive electrode bus bar 4 is disposed on the top surface of the cell stack 2 so as to be in contact with each of the positive electrode tabs 15 b of the plurality of positive electrode current collector plates 15. Similarly, the negative electrode bus bar 5 is disposed on the top surface of the cell stack 2 so as to be in contact with each of the negative electrode tabs 16 b of the plurality of negative electrode current collector plates 16.

  Subsequently, in step S05, the positive electrode bus bar 4 and the positive electrode current collector plate 15 (positive electrode tab 15b) are joined by, for example, laser welding. Thereby, the welding part W1 which joins the positive electrode bus bar 4 and the positive electrode tab 15b is formed. Similarly, the negative electrode bus bar 5 and the negative electrode current collector plate 16 (negative electrode tab 16b) are joined by, for example, laser welding. As a result, a welded portion W2 that joins the negative electrode bus bar 5 and the negative electrode tab 16b is formed.

  Through the above steps, the power storage device 1 is manufactured.

  In the method for manufacturing the power storage device 1, when the cover member 6 is attached, the concave portions 61 of the cover member 6 and the convex portions 91 of the holding member 9 are fitted together so that the positions of the plurality of power storage cells 7 are aligned in the width direction. It is done. Thereby, the position of the some positive electrode current collection board 15 (positive electrode tab 15b) and the some negative electrode current collection board 16 (negative electrode tab 16b) is also aligned in the width direction. In this state, the positive electrode bus bar 4 is joined to each of the plurality of positive electrode current collector plates 15, and the negative electrode bus bar 5 is joined to each of the plurality of negative electrode current collector plates 16, so that each positive electrode with respect to the positive electrode bus bar 4 in the width direction. The displacement of the current collector plate 15 can be reduced, and the displacement of each negative electrode current collector plate 16 with respect to the negative electrode bus bar 5 can be reduced.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment.

  For example, in the above-described embodiment, one power storage device 1 includes one positive electrode bus bar 4 and one negative electrode bus bar 5, but is not particularly limited thereto. One power storage device 1 may include a plurality of positive electrode bus bars 4 and a plurality of negative electrode bus bars 5.

  In the above embodiment, the positive electrode bus bar 4 and the negative electrode bus bar 5 are arranged side by side in the width direction on the same side in the height direction with respect to the cell stack 2, but are not limited to this form. The positive electrode bus bar 4 may be disposed on one side in the height direction with respect to the cell stack 2, and the negative electrode bus bar 5 may be disposed on the other side in the height direction with respect to the cell stack 2.

  In the above embodiment, the positive electrode bus bar 4 and the positive electrode current collector plate 15 are joined by welding. However, other methods may be used. The same applies to the joining of the negative electrode bus bar 5 and the negative electrode current collector plate 16.

  The cover member 6 may be formed of an insulating material. Examples of the insulating material forming the cover member 6 include polyimide, PP, PPS, and PA66. In this case, the possibility that the positive electrode bus bar 4 and the negative electrode bus bar 5 are short-circuited can be reduced.

  The configuration for realizing the regulation of the displacement of the storage cell 7 in the width direction by the cover member 6 is not limited to the concave portion 61 and the convex portion 91 of the above embodiment. For example, the cover member 6 only needs to have a locking portion for locking the holding member 9 in the width direction, and the holding member 9 has a locked portion that faces the locking portion in the width direction. If you do. In other words, the locking part and the locked part only have to overlap when viewed from the width direction. Hereinafter, first to fourth modifications will be described.

(First modification)
FIG. 8 is a cross-sectional view of the power storage device according to the first modification. 8A is replaced with a configuration in which the cover member 6 is provided with the convex portion 62 instead of the configuration in which the cover member 6 is provided with the concave portion 61, and 9 is mainly different from the power storage device 1 in that a recess 92 is provided in the power storage device 9.

  The convex portion 62 is provided on the bottom surface 6c of the cover member 6, and protrudes from the bottom surface 6c toward the holding member 9 along the height direction. The convex part 62 is located in the approximate center of the cover member 6 in the width direction. The convex part 62 extends along the stacking direction. The convex part 62 extends from one claw part 6b to the other claw part 6b, for example. The convex part 62 has a top surface 62a that intersects the height direction and side surfaces 62b and 62c that intersect the width direction. The recess 92 is provided on the top surface 9 a of the holding member 9. The recess 92 penetrates the holding member 9 in the stacking direction. The recess 92 is located at the approximate center of the cover member 6 in the width direction. The concave portion 92 has a shape that fits with the convex portion 62 of the cover member 6. The recess 92 has a bottom surface 92a that intersects the height direction and side surfaces 92b and 92c that intersect the width direction. In the power storage device 1 </ b> A, the convex portion 62 fits into the concave portion 92. That is, the side surface 92b faces and contacts the side surface 62b in the width direction. The side surface 92c faces and contacts the side surface 62c in the width direction.

  With this configuration, even when force is applied to each storage cell 7 along the width direction due to vibration, the side surface 92b of the recess 92 abuts on the side surface 62b of the projection 62 in the width direction, and the side surface 92c of the recess 92 is in the width direction. , The holding member 9 is restrained from moving in the width direction. That is, the convex portion 62 functions as a locking portion that locks the holding member 9 in the width direction, and the concave portion 92 functions as a locked portion that faces the convex portion 62 in the width direction. Thereby, since each electrical storage cell 7 is suppressed from moving in the width direction with respect to the cover member 6, the relative position of the electrical storage cell 7 with respect to the cover member 6 is defined in the width direction.

  Also in power storage device 1A, the same effect as power storage device 1 is achieved. Note that the side surface 92b may be in contact with the side surface 62b in the width direction or may be separated. Similarly, the side surface 92c may be in contact with the side surface 62c in the width direction or may be separated. In any case, when the holding member 9 tries to move in the width direction, at least one of the side surface 92b and the side surface 92c abuts against the opposing side surface (the side surface 62b or the side surface 62c). Thereby, it is suppressed that the holding member 9 moves in the width direction.

(Second modification)
FIG. 9 is a cross-sectional view of a power storage device according to a second modification. The power storage device 1B shown in FIG. 9 is that the cover member 6 is provided with a through hole 63 instead of the recess 61, and the holding member 9 includes a protrusion 93 instead of the protrusion 91. Mainly different from 1. In this example, each holding member 9 includes two protrusions 93, and the cover member 6 is provided with two through holes 63 for each holding member 9.

  The through hole 63 is a through hole that penetrates the cover member 6 in the height direction. The two through holes 63 corresponding to one holding member 9 are spaced apart in the width direction of the cover member 6. The protrusion 93 is provided on the top surface 9 a of the holding member 9 and protrudes from the top surface 9 a toward the cover member 6 along the height direction. The two protrusions 93 are spaced apart from each other in the width direction of the holding member 9. The protruding portion 93 has a shape that can be inserted into the through hole 63. The protrusion part 93 is exhibiting the column shape, for example. The protrusion 93 has an outer peripheral surface 93a. In the power storage device 1 </ b> B, the protruding portion 93 is inserted through the through hole 63, and the outer peripheral surface 93 a faces the inner peripheral surface 63 a that defines the through hole 63 over the entire periphery.

  With this configuration, even if force is applied to each storage cell 7 along the width direction due to vibration, the outer peripheral surface 93a of the projecting portion 93 contacts the inner peripheral surface 63a of the through hole 63 in the width direction. However, movement in the width direction is suppressed. That is, the through hole 63 functions as a locking portion that locks the holding member 9 in the width direction, and the protruding portion 93 functions as a locked portion that faces the inner peripheral surface 63a of the through hole 63 in the width direction. . Thereby, since each electrical storage cell 7 is suppressed from moving in the width direction with respect to the cover member 6, the relative position of the electrical storage cell 7 with respect to the cover member 6 is defined in the width direction.

  Also in power storage device 1B, the same effect as power storage device 1 is achieved. In addition, the number of the protrusion parts 93 with which each holding member 9 is provided is not restricted to two. Similarly, the number of through holes 63 provided in the cover member 6 per one holding member 9 is not limited to two. Moreover, the outer peripheral surface 93a of the protrusion part 93 may be in contact with the inner peripheral surface 63a of the through hole 63 or may be separated. In any case, when the holding member 9 tries to move in the width direction, the outer peripheral surface 93a contacts the inner peripheral surface 63a, so that the holding member 9 is suppressed from moving in the width direction.

(Third Modification)
FIG. 10 is a cross-sectional view of a power storage device according to a third modification. The power storage device 1C shown in FIG. 10 is different from the power storage device 1 in that the cover member 6 is not provided with a recess 61 and the holding member 9 includes a pair of protrusions 94 instead of the protrusions 91. Is different.

  The cover member 6 has a pair of end faces 6d in the width direction. The end surface 6d extends from one claw portion 6b to the other claw portion 6b. The pair of projecting portions 94 are provided on the top surface 9a of the holding member 9, and project from the top surface 9a along the height direction. The pair of projecting portions 94 are spaced apart so as to sandwich the cover member 6 in the width direction. The protrusion 94 has a side surface 94a that intersects the width direction. In the power storage device 1C, the pair of projecting portions 94 sandwich the cover member 6 in the width direction. The side surface 94a faces the end surface 6d in the width direction.

  With this configuration, even if force is applied to each storage cell 7 along the width direction due to vibration, the side surface 94a of the protruding portion 94 abuts against the end surface 6d in the width direction, so that the holding member 9 moves in the width direction. It is suppressed. That is, the end surface 6d functions as a locking portion that locks the holding member 9 in the width direction, and the protruding portion 94 functions as a locked portion that faces the end surface 6d in the width direction. Thereby, since each electrical storage cell 7 is suppressed from moving in the width direction with respect to the cover member 6, the relative position of the electrical storage cell 7 with respect to the cover member 6 is defined in the width direction.

  The same effect as that of the power storage device 1 can be obtained in the power storage device 1C. Further, in the power storage device 1 </ b> C, when the cover member 6 is made of a conductive material such as metal, a protruding portion is provided between the positive electrode bus bar 4 and the cover member 6 and between the negative electrode bus bar 5 and the cover member 6. By interposing 94, the possibility that the positive electrode bus bar 4 and the negative electrode bus bar 5 are short-circuited via the cover member 6 can be reduced. Note that either one of the pair of protrusions 94 may be omitted. Further, the side surface 94a of the protruding portion 94 may be in contact with the end surface 6d of the cover member 6 or may be separated. In any case, when the holding member 9 tries to move in the width direction, the side surface 94a comes into contact with the end face 6d, so that the holding member 9 is prevented from moving in the width direction.

(Fourth modification)
FIG. 11 is a cross-sectional view of a power storage device according to a fourth modification. The power storage device 1D shown in FIG. 11 is mainly different from the power storage device 1 in that the cover member 6A and the cover member 6B are provided instead of the cover member 6 and the holding member 9 is not provided with the convex portion 91. .

  Each of the cover member 6A and the cover member 6B is mainly different from the cover member 6 in the shape and the arrangement position. 6 A of cover members are arrange | positioned in the end part of the cell stack 2 in the width direction in the state spaced apart from the positive electrode bus bar 4. As shown in FIG. 6 A of cover members have the main-body part 64 extended in the lamination direction, and a pair of nail | claw part (not shown) provided in the both ends of the longitudinal direction of the main-body part 64, respectively. The main body 64 has an L shape when viewed from the stacking direction. The main body portion 64 includes a first portion 64a provided along the top surface 9a of the holding member 9 and a second portion 64b provided along the side surface 9b of the holding member 9 in the width direction.

  The cover member 6 </ b> B is disposed at the other end of the cell stack 2 in the width direction while being separated from the negative electrode bus bar 5. The cover member 6B includes a main body portion 65 extending in the stacking direction, and a pair of claw portions (not shown) provided at both ends of the main body portion 65 in the longitudinal direction. The main body 65 has an L shape when viewed from the stacking direction. The main body 65 has a first portion 65a provided along the top surface 9a of the holding member 9 and a second portion 65b provided along the side surface 9c of the holding member 9 in the width direction. The side surface 9c is a surface opposite to the side surface 9b.

  When the claw portion of the cover member 6A is fixed to the outer surface of the end plate 3 by the fastening member, the first portion 64a contacts the top surface 9a and the second portion 64b contacts the side surface 9b. When the claw portion of the cover member 6B is fixed to the outer surface of the end plate 3 by the fastening member, the first portion 65a contacts the top surface 9a, and the second portion 65b contacts the side surface 9c. That is, the position of the top surface 9a of each holding member 9 is defined by the first portion 64a and the first portion 65a. The position of the side surface 9b of each holding member 9 is defined by the second portion 64b, and the position of the side surface 9c of each holding member 9 is defined by the second portion 65b.

  Thereby, it is suppressed that the holding member 9 moves not only in the height direction but also in the width direction. That is, the second portion 64b functions as a locking portion that locks the holding member 9 in the width direction, and the side surface 9b functions as a locked portion that faces the second portion 64b in the width direction. Similarly, the second portion 65b functions as a locking portion that locks the holding member 9 in the width direction, and the side surface 9c functions as a locked portion that faces the second portion 65b in the width direction. Therefore, since each power storage cell 7 is suppressed from moving in the width direction with respect to the cover member 6, the relative position of the power storage cell 7 with respect to the cover member 6 is defined in the width direction.

  Also in power storage device 1D, the same effect as power storage device 1 is achieved. One of the cover member 6A and the cover member 6B may be omitted. Further, the side surface 9b may be in contact with the second portion 64b or may be separated. Similarly, the side surface 9c may be in contact with the second portion 65b or may be separated. In any case, when the holding member 9 tries to move in the width direction, at least one of the side surface 9b and the side surface 9c comes into contact with the opposing second portion (the second portion 64b or the second portion 65b). The movement of the member 9 in the width direction is suppressed.

  DESCRIPTION OF SYMBOLS 1,1A, 1B, 1C, 1D ... Power storage device, 2 ... Cell stack, 3 ... End plate, 4 ... Positive electrode bus bar, 5 ... Negative electrode bus bar, 6, 6A, 6B ... Cover member, 6d ... End surface (locking part) , 7 ... Electric storage cell, 9 ... Holding member, 9a ... Top surface, 9b, 9c ... Side surface (locked portion), 10 ... Bipolar electrode, 15 ... Positive current collector, 16 ... Negative current collector, 61 ... Recess (Locking part), 62 ... convex part (locking part), 63 ... through hole (locking part), 64a, 65a ... first part, 64b, 65b ... second part (locking part), 91 ... convex Part (locked part), 92 ... recessed part (locked part), 93 ... projecting part (locked part), 94 ... projecting part (locked part), W1 ... welded part, W2 ... welded part.

Claims (8)

A cell stack including a plurality of power storage cells stacked along the first direction alternately through a positive electrode current collector plate and a negative electrode current collector plate;
A positive electrode bus bar extending along the first direction and joined to the positive electrode current collector plate in a second direction intersecting the first direction;
A negative electrode bus bar extending along the first direction and joined to the negative electrode current collector plate in the second direction;
A cover member extending along the first direction and provided on a top surface of the cell stack in the second direction;
With
Each of the plurality of power storage cells includes a plurality of electrodes stacked along the first direction, and a holding member that holds the plurality of electrodes.
The cover member has a locking portion for locking the holding member in a third direction intersecting the first direction and the second direction,
The holding member includes a locked portion that faces the locking portion in the third direction. The holding member has a convex portion protruding toward the cover member along the second direction,
The cover member is provided with a concave portion that fits with the convex portion,
The locking portion is the concave portion,
The power storage device according to claim 1, wherein the locked portion is the convex portion. The cover member has a convex portion protruding toward the holding member along the second direction,
The holding member is provided with a concave portion that fits the convex portion,
The locking portion is the convex portion,
The power storage device according to claim 1, wherein the locked portion is the recess. The cover member is provided with a through-hole penetrating the cover member in the second direction,
The holding member has a protruding portion that protrudes toward the cover member along the second direction and is inserted through the through hole.
The locking portion is an inner peripheral surface that defines the through hole,
The power storage device according to claim 1, wherein the locked portion is the protruding portion. The cover member has an end surface in the third direction,
The holding member protrudes along the second direction and has a protruding portion facing the end surface in the third direction;
The locking portion is the end surface,
The power storage device according to claim 1, wherein the locked portion is the protruding portion. The cover member is provided between the positive electrode bus bar and the negative electrode bus bar,
The power storage device according to any one of claims 1 to 5, wherein the cover member is made of an insulating material. The cover member includes a first portion provided along a top surface of the holding member in the second direction, and a second portion provided along a side surface of the holding member in the third direction,
The locking portion is the second portion;
The power storage device according to claim 1, wherein the locked portion is the side surface. Forming a cell stack by laminating a plurality of storage cells along a first direction alternately through a positive electrode current collector plate and a negative electrode current collector plate;
Disposing a pair of end plates at both ends in the first direction of the cell stack;
Attaching a cover member extending along the first direction to a top surface in a second direction intersecting the first direction of the cell stack;
Disposing a positive electrode bus bar and a negative electrode bus bar extending along the first direction on the top surface;
Joining the positive electrode bus bar and the positive electrode current collector plate, and joining the negative electrode bus bar and the negative electrode current collector plate;
With
Each of the plurality of power storage cells includes a plurality of electrodes stacked along the first direction, and a holding member that holds the plurality of electrodes.
The cover member has a locking portion for locking the holding member in a third direction intersecting the first direction and the second direction,
The holding member has a locked portion that faces the locking portion in the third direction;
When attaching the cover member, the positions of the plurality of power storage cells in the third direction are aligned by bringing the locking portion and the locked portion into contact with each other in the third direction. Production method.

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