JP2018160398A - Method of manufacturing power storage element and power storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a power storage element in which positioning accuracy between members forming a case is high.SOLUTION: In a method for manufacturing a power storage element according to an embodiment of the present invention, in a state where a first case member, a second case member arranged in the outside of the first case member, and a retainer for determining a distance between the first case member and the second case member by interposing the first case member and the second case member are arranged in an injection molding mold, junction resin is injected into the injection molding mold to fill gaps among the first case member, the second case member and the retainer.SELECTED DRAWING: Figure 2

Description

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

  Generally, a power storage element is formed by enclosing an electrode body in a case and enclosing an electrolytic solution. When a case formed of a material having rigidity such as metal is used for the power storage element, the case is formed of a plurality of members, and is sealed by combining the plurality of members. Specifically, a sealed case is formed by joining a lid to a bottomed cylindrical main body.

  In such a power storage element, a resin is sometimes filled between a plurality of members such as between the main body and the lid body in order to ensure the sealing performance of the case (Japanese Patent Publication No. 2009-518789). In addition, the resin filled between the plurality of members as described above can also function to join the members.

  In some cases, the storage element may require positioning accuracy between a plurality of members constituting the case of the storage element, for example, when an external terminal is provided on the lid. However, when the resin for ensuring the sealing performance is interposed between the plurality of members constituting the case as described above, it is difficult to accurately determine the relative positions between the plurality of members.

Special table 2009-518789

  In view of the above problems, it is an object of the present invention to provide a method for manufacturing a power storage element and a power storage element with high positioning accuracy between members forming a case.

  In order to solve the above problems, a method for manufacturing a power storage device according to an aspect of the present invention includes a first case member, a second case member disposed outside the first case member, and the first case. With a retainer interposed between the member and the second case member and defining a distance between the first case member and the second case member disposed in the injection mold, a bonding resin is placed in the injection mold. It is a method for manufacturing a power storage element including filling and filling a gap between the first case member, the second case member, and the retainer.

  In addition, a power storage device according to another aspect of the present invention includes a first case member, a second case member disposed outside the first case member, and between the first case member and the second case member. A retainer for determining a distance between the first case member and the second case member, a lid plate for sealing an end of the second case member, the first case member, the second case member, and A case having a bonding resin that fills the gap between the retainers, and a power storage element accommodated in the case, wherein the retainer communicates the lid plate side and the opposite side of the lid plate side, and A connecting portion that is filled with a bonding resin, and on the lid plate side of the connecting portion, the bonding resin continuous from the connecting portion forms a seating surface that comes into contact with the cover plate, and the lid of the connecting portion Continuing from the crossing section on the opposite side of the plate side Serial bonding resin is a storage element that forms a seal in contact with both of said first case member and the second case member.

  The method for manufacturing a power storage element according to one aspect of the present invention and the power storage element according to another aspect of the present invention can position between the first case member and the second case member constituting the case with high accuracy. .

It is a typical front view showing an electrical storage element concerning one embodiment of the present invention. It is typical AA sectional view taken on the line of the electrical storage element of FIG. It is a typical perspective view which shows the retainer of the electrical storage element of FIG. FIG. 3 is a schematic cross-sectional view showing one manufacturing process of the electricity storage device of FIG. 1. It is typical sectional drawing of the electrical storage element which concerns on embodiment different from FIG. 1 of this invention. It is a typical perspective view which shows the retainer of the electrical storage element of FIG.

  A method for manufacturing a power storage device according to an aspect of the present invention includes a first case member, a second case member disposed outside the first case member, and the first case member and the second case member. In a state where the retainer that determines the interval between the first case member and the second case member is disposed in the injection mold, the bonding resin is injected into the injection mold, and the first case member is inserted. Filling the gap between the second case member and the retainer.

  In the method of manufacturing the electricity storage element, so-called insert molding is performed in which a first case member, a second case member, and a retainer are arranged in a mold and a bonding resin is injected. As a result, the positional relationship between the first case member and the second case member becomes accurate, and the first case member and the second case member can be connected in an airtight manner.

  It is preferable that the injection mold has a seat surface forming portion for forming a seat surface of a cover plate disposed inside the end portion of the second case member with the bonding resin. According to this configuration, the seating surface of the lid plate can be formed with high accuracy, so that the positioning accuracy of the lid plate can also be improved.

  It is preferable that the retainer has a transition portion that communicates the seat surface forming portion side and the opposite side of the seat surface forming portion. According to this configuration, the bonding resin can accurately form the seating surface on one side of the retainer, and the first case member and the second case member can be bonded on the other side of the retainer. Both accuracy and airtightness can be improved.

  It is preferable that the transition part has a thickness of 0.1 mm or more and 1.0 mm or less smaller than a part other than the transition part. According to this configuration, the bonding resin can be sufficiently supplied to the seat surface forming portion side and the opposite side, and the first case member and the second case member can be bonded more reliably.

  It is preferable that the retainer has a first convex portion that comes into contact with an end surface of the second case member opposite to the seating surface of the lid plate. According to this configuration, since the relative position between the second case member and the retainer can be accurately determined, a space into which the bonding resin is injected is accurately ensured, and the first case member and the second case member are joined. Bonding with resin becomes more reliable.

  It is preferable that the retainer has a second convex portion that contacts the end surface of the first case member. Even with this configuration, the relative position between the first case member and the retainer can be accurately determined, so that a space into which the bonding resin is injected is accurately ensured, and the bonding resin between the first case member and the second case member is secured. The joining by becomes more reliable.

  The second case member preferably has an injection hole communicating with the gate of the injection mold. According to this configuration, it is easy to spread the bonding resin in the gap between the first case member and the second case member, and the bonding by the bonding resin between the first case member and the second case member is further ensured.

  It is preferable that the retainer has a through hole communicating with the injection hole. According to this configuration, it becomes easy to inject the bonding resin into the outside and the inside of the retainer, and the bonding between the first case member and the second case member by the bonding resin is further ensured.

  Preferably, the first case member and the second case member are cylindrical, and the bonding resin is injected over the entire circumference between the first case member and the second case member. According to this configuration, the sealing property of the case can be further improved.

  It is preferable that the cylindrical part of the first case member and the second case member have a rectangular cylindrical shape. According to this structure, the electrical storage element formed by laminating | stacking a positive electrode and a negative electrode can be accommodated efficiently.

  An electricity storage device according to another aspect of the present invention includes a first case member, a second case member disposed outside the first case member, and interposed between the first case member and the second case member. And a retainer for determining a distance between the first case member and the second case member, a lid plate for sealing an end of the second case member, the first case member, the second case member, and the retainer. And a storage element accommodated in the case, wherein the retainer communicates the lid plate side and the opposite side of the lid plate side, and the bonding resin. The connecting resin is formed on the lid plate side of the transition portion to form a seating surface on which the bonding resin continuous from the transition portion abuts the lid plate, and the transition plate has the lid plate side. On the opposite side to the above, Resin is a storage element storage element forming a seal in contact with both of said first case member and the second case member.

  The first case member, the second case member, and the retainer are placed in the mold and so-called insert molding is performed to inject the bonding resin, so that the positional relationship between the first case member and the second case member is accurate and the first case. A power storage element in which the member and the second case member are hermetically connected can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[First embodiment]
1 and 2 show a power storage device according to the first embodiment of the present invention. The power storage element includes a case 1 and a power storage element 2 accommodated in the case 1.

  The case 1 has a pair of parallel long side surfaces and a pair of short side surfaces that connect the pair of long side surfaces. In the following description, the axial direction of the case 1 is the X-axis direction, the direction perpendicular to the X-axis direction and the long side surface extends is the Y-axis direction, and the direction perpendicular to the X-axis direction and the Y-axis direction is the Z-axis. Sometimes called direction. FIG. 2 is a diagram in which the power storage element is cut along the XZ plane, showing a cut surface at the right side of the center at the center in the Y direction and a cut surface at a position at the left side of the center shifted from the center in the Y direction. .

〔Case〕
The case 1 includes a first case member 3 formed in a square tube shape, a pair of second case members 4 in a square tube shape disposed outside both ends of the first case member 3, and the first case member 3. And a pair of retainers 5 that are interposed between the second case member 4 and determine the distance between the first case member 3 and the second case member 4, and a pair of cover plates 6 that seal the ends of the second case member 4. And a bonding resin 7 filling a gap between the first case member 3, the second case member 4, the retainer 5, and the cover plate 6. The case 1 has a seat surface 8 formed by the bonding resin 7 on both sides in the X-axis direction, with which the lid plate 6 abuts.

<First case member>
The first case member 3 is a rectangular cylindrical body that constitutes the case 1. The first case member 3 is formed from a material having rigidity.

  Examples of the material of the first case member 3 include metals such as iron, aluminum, stainless steel, and nickel. Among them, aluminum having excellent formability is preferably used.

<Second case member>
The second case member 4 is disposed outside the end portion of the first case member 3 in a state of being electrically insulated from the first case member 3.

  The second case member 4 is a square cylindrical body that surrounds the outer periphery of the end portion of the first case member 3 with a certain interval. That is, the second case member 4 has a pair of parallel long side surfaces corresponding to the shape of the first case member 3 and a pair of parallel short side surfaces connecting the pair of long side surfaces. The second case member 4 is disposed so as to protrude from the first case member 3 to the X-axis direction outer side of the first case member 3 so as to surround the outer periphery of the lid plate 6.

  The material of the second case member 4 is preferably a metal of the same type as the lid plate 6 so that the lid plate 6 can be easily welded.

  The second case member 4 preferably has an injection hole 9 for injecting the bonding resin 7 into the gap with the first case member 3.

(Injection hole)
The injection hole 9 is preferably formed in the central portion (Y direction central portion) of the long side surface of the second case member 4 as viewed in the X-axis direction so as to facilitate the injection of the bonding resin 7.

<Retainer>
As shown in FIG. 3, the retainer 5 is a substantially square cylindrical or square frame spacer disposed between the first case member 3 and each second case member 4. The first case member 3 is held so as to have a constant interval.

  The retainer 5 connects the joining grooves 10 and 11 to the pair of joining grooves 10 and 11 formed over the entire circumference on the first case member 3 side and the second case member 4 side and filled with the joining resin 7. And two through holes 12 formed as described above. The connection grooves 10 and 11 are formed in the central portion of the retainer 5 in the X-axis direction. Further, the retainer 5 includes a crossing portion 13 extending in the X-axis direction so as to communicate the lid plate 6 side and the joining groove 10 on the second case member 4 side located on the opposite side of the lid plate 6, and the second case member 4. The first convex portion 14 that abuts on the end surface opposite to the cover plate 6 and the second convex portion 15 that abuts on the end surface of the first case member 3 are provided.

(Joining groove)
The retainer 5 is connected to the first case member 3 and the second case member 4 by filling the bonding grooves 10 and 11 with the bonding resin 7. The joining grooves 10 and 11 may be formed only in a part of the retainer in the circumferential direction, but are preferably formed over the entire circumference of the retainer 5. The bonding grooves 10 and 11 are formed over the entire circumference, and the bonding resin 7 is injected over the entire circumference between the first case member 3 and the second case member 4, thereby improving the airtightness.

  The average depth of the joining grooves 10 and 11 is preferably 0.1 mm or more and 0.5 mm or less. By setting the average depth of the bonding grooves 10 and 11 to be equal to or higher than the lower limit, the injection of the bonding resin 7 into the bonding grooves 10 and 11 can be ensured. In addition, by setting the average depth of the joining grooves 10 and 11 to be equal to or lower than the above upper limit, the thickness of the retainer 5 and thus the size of the electric storage element can be made relatively small.

  The average width of the joining grooves 10 and 11 is preferably 1.0 mm or more and 5.0 mm or less. By setting the average width of the joining grooves 10 and 11 to be equal to or greater than the above lower limit, the airtightness between the retainer 5, the first case member 3, and the second case member 4 can be further ensured. Moreover, the filling amount of the joining resin required can be reduced by making the average width | variety of the joining grooves 10 and 11 or less into the said upper limit.

(Through hole)
The through hole 12 is preferably formed to communicate with the injection hole 9 of the second case member 4 in order to facilitate filling of the bonding resin 7 into the bonding groove 11 on the first case member 1 side. That is, it is preferable that the through hole 12 and the injection hole 9 are formed so that at least a part thereof overlaps when viewed in the Z-axis direction.

  The average diameter of the through holes 12 is preferably 2.0 mm or greater and 3.0 mm or less. By making the average diameter of the through holes 12 within the above range, the bonding resin 7 can be more easily filled into the bonding grooves 11 on the first case member 1 side. The “average diameter” means the equivalent circle diameter.

(Transition part)
The crossover portion 13 is formed by partially reducing the thickness of the retainer 5. Moreover, the retainer 5 may have a plurality of transition portions 13, and each of the first case members 3 has the transition portions 13 on the outer sides of the pair of long side centers when viewed in the axial direction (viewed in the X-axis direction). Is preferred.

  In order to facilitate filling of the bonding resin 7, the crossover portion 13 has a through hole 12 and a second case member 4 on one end side of the crossover portion 13 as viewed in the normal direction of the surface of the retainer 5 on the second case member 4 side. The injection hole 9 is preferably formed so as to be located. By filling the joining resin 7 in the crossover portion 13, the joining resin 7 that fills the lid plate 6 side of the retainer 5 and forms the seating surface 8 and the lid plate 6 are in the joining grooves 10 and 11 on the opposite side. The bonding resin 7 to be filled can be integrally formed. Further, since the bonding resin 7 on the lid plate 6 side and the bonding resin 7 in the bonding grooves 10 and 11 are integrated, the airtightness between the first case member 3 and the second case member 4 and the first case are provided. The bonding strength between the member 3 and the second case member 4 and the bonding resin 7 is improved.

  As the average depth of the crossover portion 13 (the thickness of the portion other than the crossover portion 13 of the retainer 5, that is, the difference between the average distance between the first case member 3 and the second case member 4 and the thickness at the crossover portion 13) Is preferably 0.1 mm or more and 1.0 mm or less. By setting the average depth of the transition portion 13 to be equal to or higher than the lower limit, the injection of the bonding resin 7 into the transition portion 13 can be ensured. In addition, by setting the average depth of the crossover portion 13 to be equal to or less than the above upper limit, the thickness of the retainer 5 and thus the dimensional difference between the first case member 3 and the second case member 4 in the X-axis direction view can be reduced. it can.

  The average width of the transition portion 13 is preferably 10 mm or more and 20 mm or less. By setting the average width of the transition portion 13 to the above lower limit or more, the bonding resin 7 on both sides of the transition portion 13 can be more reliably connected. Moreover, the intensity | strength fall of the retainer 5 can be suppressed by making the average width of the transition part 13 below into the said upper limit.

(First convex part)
The first convex portion 14 abuts on the end portion of the second case member 4 on the side opposite to the cover plate 6 and determines the position of the second case member 4 in the X-axis direction. The first convex portion 14 is a convex portion that protrudes on the opposite side to the first case 3. In the present embodiment, the first convex portion 14 is formed over the entire circumference of the retainer 5. The first convex portion 14 may be formed on a part of the periphery of the retainer 5.

(Second convex part)
The second convex portion 15 is in contact with the end portion of the first case member 3 on the cover plate 6 side, and determines the position of the retainer 5 with respect to the first case member 3 in the X-axis direction. That is, the second protrusion 15 is a protrusion that protrudes toward the inside of the first case 3. In the present embodiment, the second convex portion 15 is formed over the entire circumference of the retainer 5. The second convex portion 15 may be formed on a part of the periphery of the retainer 5.

<Cover plate>
The cover plate 6 is disposed so as to contact the seat surface 8 formed by the bonding resin 7. The outer periphery of the cover plate 6 is airtightly welded to the second case member 4. As a result, the case 1 is sealed.

  The pair of lid plates 6 are connected to the positive electrode or the negative electrode of the power storage element 2 and are used as external terminals of the power storage element. For this reason, the cover plate 6 is formed of a conductive material, and is preferably formed of a metal that can be used for a positive or negative current collector to which the electricity storage element 2 is connected.

  Specifically, examples of the material of the one cover plate 6 connected to the positive electrode of the electricity storage element 2 include metals such as aluminum, titanium, tantalum, and stainless steel, or alloys thereof. Among these, aluminum and aluminum alloys are preferable from the balance of potential resistance, high conductivity and cost. Examples of aluminum or aluminum alloy include A1085P and A3003P defined in JIS-H4000 (2014).

  Further, examples of the material of the other cover plate 6 connected to the negative electrode of the electricity storage element 2 include metals such as copper, nickel, stainless steel, nickel-plated steel, aluminum, and alloys thereof, and nickel having excellent strength. Plated steel is preferred.

  The average thickness of the cover plate 6 is a thickness that provides sufficient strength, and can be, for example, 0.3 mm or more and 1.0 mm or less, depending on the material.

<Bonding resin>
The bonding resin 7 is injected into the front-side bonding groove 10 from the injection hole 9 of the second case member 4, filled into the bonding groove 11 provided on the first case member 3 side through the through hole 12, and the crossover part 13. Then, it flows into the lid plate 6 side, and an end portion having a seating surface 8 is formed by a mold as will be described later.

  The bonding resin 7 may be any resin that can be injected into the gap between the first case member 3, the second case member 4, the retainer 5, and the cover plate 6 and can be cured after the injection, and may be a thermoplastic resin. It may be a thermosetting resin. Specific examples of the main component of the bonding resin 7 include polyphenylene sulfide and polypropylene.

[Storage element]
The power storage element 2 includes an electrode body 19 formed by laminating a positive electrode plate 16 and a negative electrode plate 17 via a separator 18, and a tab 20 extending from the positive electrode plate 16 and the negative electrode plate 17 and connected to the lid plate 6. . The electricity storage element 2 is enclosed in the case 1 together with the electrolyte.

(Positive electrode plate)
The positive electrode plate 16 includes a conductive foil-like or sheet-like positive electrode current collector and a positive electrode active material layer laminated on both surfaces of the positive electrode current collector.

  As a material of the positive electrode current collector of the positive electrode plate 16, a metal such as aluminum, copper, iron, nickel, or an alloy thereof is used. Among these, aluminum, an aluminum alloy, copper, and a copper alloy are preferable from the balance between high conductivity and cost, and aluminum and an aluminum alloy are more preferable. Moreover, as a shape of a positive electrode electrical power collector, foil, a vapor deposition film, etc. are mentioned, A foil is preferable from the surface of cost. That is, an aluminum foil is preferable as the positive electrode current collector.

  The positive electrode active material layer of the positive electrode plate 16 is a porous layer formed from a so-called mixture containing a positive electrode active material. Moreover, the composite material which forms a positive electrode active material layer contains arbitrary components, such as a electrically conductive agent, a binder (binder), a thickener, and a filler, as needed.

Examples of the positive electrode active material include composite oxides represented by Li _x MO _y (M represents at least one transition metal) (Li _x CoO ₂ , Li _x NiO ₂ , Li _x Mn ₂ O ₄ , Li _{x MnO 3, Li x Ni α Co} (1-α) O 2, Li x Ni α Mn β Co (1-α-β) O 2, Li x Ni α Mn (2-α) O 4 , etc.), Li _w A polyanion compound (LiFePO ₄ , LiMnPO ₄ , LiNiPO ₄ , LiCoPO ₄ ) represented by Me _x (XO _y ) _z (Me represents at least one transition metal, and X represents, for example, P, Si, B, V, etc.) Li ₃ V ₂ (PO ₄ ) ₃ , Li ₂ MnSiO ₄ , Li ₂ CoPO ₄ F, etc.). The elements or polyanions in these compounds may be partially substituted with other elements or anion species. In the positive electrode active material layer, one kind of these compounds may be used alone, or two or more kinds may be mixed and used. The crystal structure of the positive electrode active material is preferably a layered structure or a spinel structure.

(Negative electrode plate)
The negative electrode plate 17 includes a conductive foil-shaped or sheet-shaped negative electrode current collector, and a porous negative electrode active material layer laminated on both surfaces of the negative electrode current collector.

  The material of the negative electrode current collector of the negative electrode plate 17 is preferably copper or a copper alloy. Moreover, as a shape of a negative electrode collector, foil is preferable. That is, the negative electrode current collector of the negative electrode plate 17 is preferably a copper foil. Examples of the copper foil used as the negative electrode current collector include a rolled copper foil and an electrolytic copper foil.

  The negative electrode active material layer is formed in a layer form from a so-called composite material containing a negative electrode active material. Moreover, the composite material which forms a negative electrode active material layer is formed from the porous material containing arbitrary components, such as a electrically conductive agent, a binder (binder), a thickener, and a filler as needed. Moreover, the composite material which forms a negative electrode active material layer contains arbitrary components, such as a electrically conductive agent, a binder (binder), a thickener, and a filler as needed.

  As the negative electrode active material, a material capable of inserting and extracting lithium ions is preferably used. Specific examples of the negative electrode active material include metals such as lithium and lithium alloys, metal oxides, polyphosphate compounds, carbon materials such as graphite and amorphous carbon (easily graphitizable carbon or non-graphitizable carbon). Can be mentioned.

  Among the negative electrode active materials, Si, Si oxide, Sn, Sn oxide, or a combination thereof is used from the viewpoint of setting the discharge capacity per unit facing area between the positive electrode plate 16 and the negative electrode plate 17 to a suitable range. It is preferable to use Si oxide. Si and Sn can have a discharge capacity about three times that of graphite when they are made into oxides.

(separator)
The separator 18 is formed from a sheet-like or film-like material into which the electrolytic solution is infiltrated. As a material for forming the separator 18, for example, a woven fabric, a non-woven fabric, or the like can be used. Typically, a porous sheet-like or film-like resin is used. The separator 18 separates the positive electrode plate 16 and the negative electrode plate 17 and holds an electrolytic solution between the positive electrode plate 16 and the negative electrode plate 17.

  Examples of the main component of the separator 18 include polyolefins such as polyethylene (PE), polypropylene (PP), ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, and chlorinated polyethylene. Derivatives, polyolefins such as ethylene-propylene copolymers, and polyesters such as polyethylene terephthalate and copolymerized polyesters can be employed. Among these, as the main component of the separator 18, polyethylene and polypropylene excellent in electrolytic solution resistance, durability, and weldability are preferably used.

  The separator 18 preferably has a heat-resistant layer on both sides or one side (preferably the side facing the positive electrode plate 16). Thereby, damage to the separator 18 due to heat can be prevented, and a short circuit between the positive electrode plate 16 and the negative electrode plate 17 can be more reliably prevented.

  The heat-resistant layer of the separator 18 can include a large number of inorganic particles and a binder that connects the inorganic particles.

  As the main component of the inorganic particles, for example, oxides such as alumina, silica, zirconia, titania, magnesia, ceria, yttria, zinc oxide, iron oxide, nitrides such as silicon nitride, titanium nitride, boron nitride, silicon carbide, carbonate Calcium, aluminum sulfate, aluminum hydroxide, potassium titanate, talc, kaolin clay, kaolinite, halloysite, pyrophyllite, montmorillonite, sericite, mica, amicite, bentonite, asbestos, zeolite, calcium silicate, magnesium silicate Etc. Among these, alumina, silica and titania are particularly preferable as the main component of the inorganic particles of the heat-resistant layer.

<Tab>
The tab 20 is formed by extending the positive electrode current collector and the negative electrode current collector of the positive electrode plate 16 and the negative electrode plate 17 so as to protrude from the rectangular positive electrode active material layer lamination region and the negative electrode active material layer lamination region, respectively. be able to. The tab 20 extending from the positive electrode plate 16 and the tab 20 extending from the negative electrode plate 17 protrude to the opposite sides and are electrically and mechanically connected to the lid plate 6, respectively. These tabs 20 may be a bundle of a plurality of positive electrode current collectors extending from the plurality of positive electrode plates 16 or a plurality of negative electrode current collectors extending from the plurality of negative electrode plates 17.

<Electrolyte>
As the electrolyte enclosed in the case 1 together with the power storage element 2, known electrolyte solutions and solid electrolytes usually used for power storage elements can be used. Examples of the electrolytic solution include cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC), and butylene carbonate (BC), or chains such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC). A solution in which lithium hexafluorophosphate (LiPF ₆ ) or the like is dissolved in a solvent containing a carbonate can be used.

[Method for producing power storage element]
As shown in FIG. 4, the power storage element has the first case member 3, the second case member 4, and the retainer 5 disposed in the injection mold 100, and the bonding resin 7 is placed in the injection mold 100. It can be manufactured by a method including filling and filling a gap between the first case member 3, the second case member 4 and the retainer 5.

<Injection mold>
The injection mold 100 has a gate 101 that communicates with the injection hole 9 of the second case member 4 and a seating surface 8 that contacts the lid plate 6 disposed inside the end portion of the second case member 4 by a bonding resin 7. And a seat surface forming portion 102 to be formed.

  Using such an injection mold 100, the first case member 3, the second case member 4, and the retainer 5 are bonded by injecting the bonding resin 7 into the space left in the injection mold 100 and curing it. The resin 7 can be airtightly joined.

  By forming the seating surface 8 by the seating surface forming portion 102 of the injection mold 100, the seating surface 8 can be formed exactly perpendicular to the X-axis direction of the first case member 3, and the pair of lid plates 6 The degree of parallelism can be improved.

[Second Embodiment]
FIG. 5 shows an end portion of the energy storage device according to the second embodiment of the present invention. The power storage element includes a case 21 and a power storage element 2 accommodated in the case 21. The power storage element 2 in the power storage element of FIG. 5 can be the same as the power storage element 2 in the power storage element of FIG.

〔Case〕
The case 21 includes a first case member 3 formed in a square tube shape, a pair of square case-like second case members 4 disposed outside both ends of the first case member 3, and the first case member 3. And a pair of retainers 22 that are interposed between the second case member 4 and determine the distance between the first case member 3 and the second case member 4, and a pair of lid plates 6 that seal the ends of the second case member 4. And a bonding resin 7 filling a gap between the first case member 3, the second case member 4, the retainer 5, and the cover plate 6.

  The first case member 3, the second case member 4 and the cover plate 6 of the case 21 in the power storage element of FIG. 5 are the first case member 3, the second case member 4 and the cover plate 6 of the case 1 in the power storage element of FIG. And can be similar. Further, the bonding resin 7 in the electric storage element of FIG. 5 is bonded to the electric storage element in FIG. 1 except for the difference in shape due to the difference in shape of the retainer 22 in the electric storage element in FIG. 5 from the retainer 5 in the electric storage element in FIG. It can be the same as that of the resin 7.

<Retainer>
As shown in FIG. 6, the retainer 22 is a spacer having a substantially rectangular tube shape or a rectangular frame shape disposed between the first case member 3 and each second case member 4. The first case member 3 is held so as to have a constant interval.

  The retainer 22 is considerably shorter in the X-axis direction than the second case member 4, and does not exist on the opposite side of the cover plate 6 in the gap between the first case member 3 and the second case member 4. For this reason, the part opposite to the cover plate 6 in the gap between the first case member 3 and the second case member 4 is filled only with the bonding resin 7. The bonding resin 7 protrudes from the second case member 4 to the opposite side of the lid plate 6 and covers the end surface of the second case member 4.

  In addition, the retainer 22 contacts the crossing portion 23 extending over the entire X-axis direction so as to communicate the lid plate 6 side and the opposite side of the lid plate 6, and the end surface of the first case member 3 on the lid plate 6 side. And a convex portion 24 in contact therewith.

(Transition part)
The crossover part 23 is a part obtained by reducing the entire thickness of a part of the circumferential direction so as to leave only the convex part 24 overlapping the first case member 3 when viewed in the X-axis direction.

(Convex)
The convex portion 24 is in contact with the end portion of the first case member 3 on the cover plate 6 side, and determines the position of the retainer 22 in the X-axis direction with respect to the first case member 3.

[Other Embodiments]
The said embodiment does not limit the structure of this invention. Therefore, in the above-described embodiment, the components of each part of the above-described embodiment can be omitted, replaced, or added based on the description and common general knowledge of the present specification, and they are all interpreted as belonging to the scope of the present invention. Should.

  The power storage element is one in which the cover plate is not electrically connected to the power storage element, that is, the cover plate is not used as an external terminal or an electric circuit, and the cover plate is provided with an external terminal electrically connected to the power storage element. There may be.

  An assembled battery can be formed by connecting a plurality of the power storage elements with a conductive connection member (bus bar). The bus bar is preferably connected to the lid plate functioning as an external terminal by welding. When the bus bar and the cover plate are connected by welding, if the position accuracy of the cover plate is low, the distance between the bus bar and the cover plate becomes non-uniform, so that the welding becomes non-uniform and the weld quality may be lowered. If the welding quality is low, the welding strength is low and the electric resistance at the welded portion is high, which is not preferable. Therefore, it is preferable that the positional accuracy of the cover plate is high. According to the present invention, since the position of the lid plate can be determined with high accuracy, the accuracy of welding between the connecting member and the lid plate can be improved. Even when an external terminal is provided on the cover plate separately from the cover plate, the position accuracy of the external terminal is improved as a result of improving the position accuracy of the cover plate, so the welding quality with the bus bar is also improved. Can be made.

  In the power storage element, the first case member may be formed in a bottomed cylindrical shape, and the second case member and the cover plate may be provided only on the opening end side of the first case member.

  In the power storage element, the power storage element may be a stacked type or a wound type.

  In the power storage element, the bonding resin may be injected into a part of the circumference between the first case member and the second case member. In this case, it is preferable to have a seal member that ensures airtightness between the first case member and the second case member.

  The power storage element can be particularly suitably used as a power source for an automobile or the like.

DESCRIPTION OF SYMBOLS 1 Case 2 Power storage element 3 1st case member 4 2nd case member 5 Retainer 6 Cover plate 7 Bonding resin 8 Seat surface 9 Injection hole 10, 11 Joining groove 12 Through-hole 13 Transition part 14 First convex part 15 Second convex part 16 Positive electrode plate 17 Negative electrode plate 18 Separator 19 Electrode body 20 Tab 21 Case 22 Retainer 23 Crossing portion 24 Convex portion 100 Mold 101 Gate 102 Seat surface forming portion

Claims (11)

  A first case member, a second case member disposed outside the first case member, and the first case member and the second case member interposed between the first case member and the second case member. In a state where the retainer for determining the interval is arranged in the injection mold, a bonding resin is injected into the injection mold to fill the gap between the first case member, the second case member, and the retainer. A method for manufacturing a power storage element. The method for manufacturing a power storage element according to claim 1, wherein the injection mold includes a seating surface forming portion that forms a seating surface of a cover plate disposed inside an end portion of the second case member with the bonding resin. The method for manufacturing a power storage element according to claim 2, wherein the retainer has a crossing portion that communicates the seat surface forming portion side and the opposite side of the seat surface forming portion. The method for manufacturing a power storage element according to claim 3, wherein the transition part has a thickness of 0.1 mm or greater and 1.0 mm or less smaller than a part other than the transition part. 5. The method for manufacturing a power storage element according to claim 2, wherein the retainer has a first convex portion that comes into contact with an end surface of the second case member opposite to the seating surface of the lid plate. . The method for manufacturing a power storage element according to any one of claims 1 to 5, wherein the retainer has a second convex portion that comes into contact with an end face of the first case member. The method for manufacturing a power storage element according to any one of claims 1 to 6, wherein the second case member has an injection hole that communicates with a gate of the injection mold. The method for manufacturing a power storage element according to claim 7, wherein the retainer has a through hole communicating with the injection hole. The first case member and the second case member are cylindrical,
The method for manufacturing a power storage element according to any one of claims 1 to 8, wherein the bonding resin is injected over the entire circumference between the first case member and the second case member. The method for manufacturing a power storage element according to claim 9, wherein the first case member and the second case member have a rectangular tube shape. A first case member;
A second case member disposed outside the first case member;
A retainer that is interposed between the first case member and the second case member to determine a distance between the first case member and the second case member;
A lid plate for sealing the end of the second case member;
A case having a bonding resin that fills a gap between the first case member, the second case member, and the retainer;
A power storage element housed in the case,
The retainer has a transition portion that communicates the lid plate side and the opposite side of the lid plate side and is filled with the bonding resin;
On the lid plate side of the crossover portion, the bonding resin continuous from the crossover portion forms a seating surface that comes into contact with the lid plate,
The electricity storage element which forms the sealing part which the said joining resin continuous from the said transition part contact | abuts to both the said 1st case member and the said 2nd case member on the opposite side to the said cover plate side of the said transition part.

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