JP2013021347A - Electrochemical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrochemical device which can avoid defects such as increase in a resistance value caused by an arrangement position of a storage element being different from a desired position (a position determined in a design stage) and prevent deterioration of charge/discharge characteristics.SOLUTION: In an electrochemical device 10, three protruding parts 19a in all, protruding toward a lower surface of a first electrode sheet 13a of a storage element 13, are formed on an upper surface of a collecting film 19. A tip part of each protruding part 19a bites the lower surface of the first electrode sheet 13a of the storage element 13, by this bite an arrangement position of the storage element 13 in a closed recessed part 11a is determined.

Description

  The present invention relates to an electrochemical device enclosing a chargeable / dischargeable power storage element.

  For electronic devices such as mobile phones, laptop computers, video cameras, and digital cameras, surface mountable electrochemical devices such as electric double layer capacitors and lithium ion batteries are used as power sources suitable for memory backup applications. It has been.

  This electrochemical device generally includes an insulating case having a recess in the upper surface opening, a conductive lid in which the recess in the case is closed in a watertight and airtight manner, a chargeable / dischargeable storage element enclosed in the closed recess, and An electrolyte, a positive electrode terminal and a negative electrode terminal provided on the mounting surface of the case, a positive electrode wiring for electrically connecting the positive electrode terminal and the positive electrode side of the energy storage device, and the negative electrode terminal and the negative electrode side of the energy storage device And a negative electrode wiring for electrically connecting the two (refer to Patent Documents 1 and 2).

  In addition, when one pole side of the power storage element faces the bottom surface of the recess and the other pole side faces the inner surface of the lid, a current collector film is usually provided on the bottom surface of the recess, and the top surface of the current collector film The surface on the one electrode side of the electricity storage element is electrically connected to the surface of the electricity storage element via a conductive adhesive layer, and the surface on the other electrode side of the electricity storage element is electrically connected to the lower surface of the lid via another conductive adhesive layer. They are connected (see Patent Document 2).

  Incidentally, when one surface of the electricity storage element is electrically connected to the upper surface of the current collecting film via a conductive adhesive layer, and the other surface of the electricity storage element is connected to the lower surface of the lid via another conductive adhesive layer. When the pole side surface is electrically connected, that is, in the step of arranging the storage element, the one pole side surface is pressed against the uncured conductive adhesive applied to the upper surface of the current collector film to conduct the conductive operation. Before and after this, a method is adopted in which the other adhesive side surface is pressed against the uncured conductive adhesive applied to the lower surface of the lid to cure the conductive adhesive. Yes.

  However, since the uncured conductive adhesive has fluidity, in the process of pressing the one pole side surface or the other pole side surface against the conductive adhesive, the one pole side is substantially the same as the upper surface of the current collector film. There is a case where it is displaced in a parallel direction, or the other pole side is displaced in a direction substantially parallel to the lower surface of the lid. In addition, since the surfaces are bonded to each other through the conductive adhesive layer, when an impact is applied to the electrochemical devices before and after mounting and a displacement stress based on the impact acts on the interface of the conductive adhesive layer, the closed recess There is also a risk of causing a shift in the electric storage element arranged inside.

  If such a misalignment occurs, the location of the storage element in the closed recess will differ from the intended position (position determined by design), and charging and discharging will cause problems such as increased resistance due to the difference. There is a risk of deteriorating characteristics.

JP 2009-278068 A JP 2006-222221 A

  An object of the present invention is to provide an electric device capable of preventing deterioration of charge / discharge characteristics by avoiding problems such as an increase in resistance value caused by a difference in arrangement position of a storage element from an intended position (position determined by design). To provide chemical devices.

  In order to achieve the above object, an electrochemical device according to an aspect of the present invention includes a case having a recessed portion of an opening, a lid coupled to the opening side of the case and forming a closed portion between the recessed portion, A current collecting film provided on a bottom surface of the closed part; a chargeable / dischargeable power storage element enclosed in the closed part; and the current collector film and the power storage element disposed between the current collector film and the power storage element A first conductive adhesive layer that electrically connects the lid, and a second conductive adhesive layer that is disposed between the lid and the power storage element and that electrically connects the lid and the power storage element; It has a tip portion that bites into the power storage element, and includes at least one convex portion that is formed on at least one of the current collecting film and the lid and protrudes toward the power storage element.

  According to the present invention, at least a tip portion of at least one convex portion formed on at least one of the current collector film and the lid bites into the electric storage element, and the arrangement of the electric storage element in the closed concave portion by the biting in Since the position can be determined, it is possible to avoid the deterioration of charge / discharge characteristics by avoiding problems such as an increase in resistance value caused by the disposition of the storage element being different from the intended position (position determined by design). Can do.

  The above object and other objects, structural features, and operational effects of the present invention will become apparent from the following description and the accompanying drawings.

It is an external appearance perspective view of the electrochemical device (1st Embodiment) to which this invention is applied. It is an expanded sectional view which follows the S11-S11 line | wire of the electrochemical device shown in FIG. It is an enlarged top view of the case shown in FIG. It is a figure for demonstrating the arrangement | positioning method of the electrical storage element shown in FIG. It is sectional drawing corresponding to FIG. 2 of the electrochemical device (2nd Embodiment) to which this invention is applied. It is sectional drawing corresponding to FIG. 2 of the electrochemical device (3rd Embodiment) to which this invention is applied.

[First Embodiment]
1 to 4 show an electrochemical device (first embodiment) to which the present invention is applied. The electrochemical device 10 shown in FIGS. 1 and 2 includes an insulating case 11, a conductive lid 12, a storage element 13, a positive electrode terminal 14, a negative electrode terminal 15, a positive electrode wiring 16, and a negative electrode wiring 17. The case 11 is provided with a positive terminal 14, a negative terminal 15, a positive wiring 16 and a negative wiring 17, and a coupling ring 18 and a current collecting film 19.

<Case configuration>
The case 11 is made of an insulating material such as alumina, and is formed in a rectangular parallelepiped shape having a predetermined length, width, and height. Further, the upper surface of the case 11 is formed with a concave portion 11a having an upper surface opening having a rectangular shape in top view and a predetermined depth. That is, the lower surface of the case 11 is used as a mounting surface. Further, at the four corners when the case 11 is viewed from above, cutouts 11b whose top view outlines form approximately ¼ circle are formed in the vertical direction. The case 11 is provided with a positive electrode terminal 14, a negative electrode terminal 15, a positive electrode wiring 16, and a negative electrode wiring 17, as well as a coupling ring 18 and a current collecting film 19.

  The positive electrode terminal 14 is made of a conductive material such as gold, and is formed to have an L-shaped cross section extending from the center to the lower surface of one end surface in the length direction of the case 11 and having a predetermined width. . The negative electrode terminal 15 is made of a conductive material such as gold, has an L-shaped cross section extending from the center of the other end surface in the length direction of the case 11 to the lower surface, and has substantially the same width as the positive electrode terminal 14. Is formed.

  Although not shown in the drawings, when the positive electrode terminal 14 and the negative electrode terminal 15 are not directly formed on the side surface and the lower surface of the case 11 due to the material of the case 11 or the like, the side surface is not obtained. In addition, an adhesion auxiliary layer (for example, a tungsten film and a nickel film arranged in order from the case side) is formed on the side surface and the lower surface of the case 11 in advance to increase the adhesion of the positive electrode terminal 14 and the negative electrode terminal 15 to the lower surface. It is good to leave.

  The positive electrode wiring 16 is made of a conductive material such as tungsten, and is formed inside the case 11 so as to reach the lower surface of the current collecting film 19 from the center of one end surface in the length direction of the case 11. Specifically, as shown in FIG. 3, the positive electrode wiring 16 includes a portion (not shown) having substantially the same width as the positive electrode terminal 14, a total of three strip portions 16 a extending inward from the portion, and each strip portion. A total of three columnar portions 16 b extending from the end of 16 a toward the current collecting film 19 are provided. The positions of the columnar portions 16b are different on the bottom surface of the concave portion 11a of the case 11, and the upper end of the substantially hemispherical shape of each columnar portion 16b protrudes above the bottom surface of the concave portion 11a. The portion of the positive electrode wiring 16 exposed from one end surface in the length direction of the case 11 is electrically connected to the side surface portion of the positive electrode terminal 14.

  The negative electrode wiring 17 is made of a conductive material such as tungsten, and a part of the negative electrode wiring 17 is formed inside the case 11 so as to reach the upper surface of the case 11 from the center of the other end surface in the length direction of the case 11, and the other part is the case. 11 are formed on the side surface and the upper surface. Specifically, as shown in FIG. 3, the negative electrode wiring 17 has a portion (not indicated by reference numeral) having substantially the same width as the negative electrode terminal 15 and positioned in the case 11, and extends outward from the portion and positioned in the case 11. A total of two strips 17a, a total of two strips 17b located on the inner surface of the two notches 11b of the case 11 continuously with each strip 17a, and a case continuous with each strip 17b 11 and a total of two fan-shaped portions 17c located on the upper surface of the head. Further, the portion of the negative electrode wiring 17 exposed from the other end surface in the length direction of the case 11 is electrically connected to the side surface portion of the negative electrode terminal 15, and each fan-shaped portion existing on the upper surface of the case 11 of the negative electrode wiring 17. 17 c is electrically connected to the lower surface of the coupling ring 18.

  The coupling ring 18 is made of a conductive material such as Kovar (iron-nickel-cobalt alloy), and is formed to have a rectangular shape with a top view outline slightly smaller than the top view outline of the case 11. Further, the top view outline of the inner hole 18 a of the coupling ring 18 substantially matches the top view outline of the recess 11 a of the case 11. Since the coupling ring 18 is coupled to the upper surface of the case 11 via a bonding material so that the inner hole 18a is aligned with the concave portion 11a, the inner hole 18a is substantially indented by cooperation with the concave portion 11a. Will be composed.

  Although not shown in the drawing, sufficient bonding force can be obtained even if the bonding ring 18 is directly bonded to the upper surface of the case 11 using a bonding material, for example, a brazing material such as a gold-copper alloy, due to the material of the case 11 or the like. Is not obtained, a bonding auxiliary layer (for example, a tungsten film and a nickel film sequentially arranged from the upper surface side in order) on the upper surface of the case 11 is previously provided on the upper surface of the case 11 to increase the bonding force of the bonding ring 18 to the upper surface. It is good to form. Further, when the coupling ring 18 is made of a material having low corrosion resistance to the electrolytic solution, a corrosion-resistant film for enhancing the corrosion resistance to the electrolytic solution (for example, a nickel film and a gold film arranged in order from the surface side, It is preferable to form a surface of the coupling ring 18 (at least the upper and lower surfaces and the inner surface of the inner hole 18a).

  The current collector film 19 is made of a conductive material such as aluminum, and is formed on the bottom surface of the recess 11a of the case 11 with a top view contour slightly smaller than the top view contour of the bottom surface. As described above, the upper end of each columnar portion 16b of the positive electrode wiring 16 is raised upward from the bottom surface of the recess 11a of the case 11, and the current collecting film 19 covers the upper end of each columnar portion 16b. As shown in FIG. 3 and FIG. 4, the upper surface of the current collecting film 19 has a substantially hemispherical convex portion 19a that protrudes along the protruding portion of each columnar portion 16b. (See (A)). Further, the current collecting film 19 formed on the bottom surface of the concave portion 11 a of the case 11 is electrically connected to the protruding portion of each columnar portion 16 b of the positive electrode wiring 16.

  Although illustration is omitted, even if the current collecting film 19 is formed on the bottom surface of the recess 11a of the case 11 due to the material of each columnar portion 16b of the positive electrode wiring 16, it is sufficient for the protruding portion of each columnar portion 16b. When electrical conduction cannot be obtained, a conductive auxiliary layer (for example, a nickel film and a gold film are arranged in this order from the surface side of the projecting portion) to enhance electrical conduction between the projecting portions of the columnar portions 16b and the current collector film 19. Etc.) may be formed in advance on the surface of the protruding portion.

<Lid configuration and coupling method>
The lid 12 is made of a conductive material such as Kovar (iron-nickel-cobalt alloy), preferably a clad material having a nickel film on the upper and lower surfaces of the Kovar base material, a clad material having a nickel film on the lower surface of the Kovar base material, These nickel films are made of a clad material obtained by changing the nickel film into a metal film such as platinum, silver, gold, or palladium, and are formed in a rectangular shape having a top view outline that substantially matches the top view outline of the coupling ring 18. In the drawing, the central portion of the lid 12 that is raised in a rectangular shape is shown as the lid 12, but a flat plate may be used as the lid 12.

  The lid 12 is configured so that the outer peripheral portion of the lower surface thereof is electrically connected to the upper surface of the coupling ring 18 after the electric storage element 13 is disposed inside the recess 11 a (including the inner hole 18 a of the coupling ring 18) of the case 11. As a result of the coupling, each recess 11a (including the inner hole 18a of the coupling ring 18) of the case 11 is closed in a watertight and airtight manner. Incidentally, for bonding the lid 12 to the coupling ring 18, a direct bonding method such as seam welding or laser welding can be used, or an indirect bonding method with a conductive bonding material can be used.

<Configuration and arrangement method of power storage element>
The power storage element 13 includes a rectangular first electrode sheet 13a, a rectangular second electrode sheet 13b, and a rectangular separate sheet 13c interposed between the electrode sheets 13a and 13b. Yes. The first electrode sheet 13a and the second electrode sheet 13b have a top view outline smaller than the top view outline of the recess 11a of the case 11, and the separate sheet 13c is slightly larger than the top view outlines of both the electrode sheets 13a and 13b. And the top view outline is slightly smaller than the top view outline of the recess 11 a of the case 11.

  The first electrode sheet 13a and the second electrode sheet 13b are made of an active material such as activated carbon or PAS (polyacenic semiconductor), and the separate sheet 13c is made of a porous sheet mainly made of glass fiber, cellulose fiber, plastic fiber, or the like. . Incidentally, the materials of the first electrode sheet 13 a and the second electrode sheet 13 b may be the same or different depending on the type of the electrochemical device 10.

  This power storage element 13 has a recess 11a (including the inner hole 18a of the coupling ring 18) closed by the lid 12 and an electrolyte solution (not shown) such as propylene carbonate (solvent) borofluoride triethylmethylammonium ( Etc.) with solute) added.

  When the polarity at the time of use is not fixed to the first electrode sheet 13a and the second electrode sheet 13b constituting the storage element 13, that is, the first electrode sheet 13a can be selectively used as one of a positive electrode and a negative electrode, and When the second electrode sheet 13b can be selectively used as the other of the positive electrode and the negative electrode, when the storage element 13 is disposed inside each recess 11a (including the inner hole 18a of the coupling ring 18) of the case 11, There is no need to worry about the insertion order.

  On the other hand, when the polarity at the time of use is predetermined in the 1st electrode sheet 13a and the 2nd electrode sheet 13b which comprise the electrical storage element 13, each recessed part 11a (including the inner hole 18a of the coupling ring 18) of the case 11 Pay attention to the order of insertion when the power storage element 13 is placed inside the. For example, when the polarity of the first electrode sheet 13 a is set to the positive electrode and the polarity of the second electrode sheet 13 b is set to the negative electrode, the first electrode sheet 13 a on the positive electrode side is the upper surface of the current collector film 19. And the second electrode sheet 13b on the negative electrode side faces the lower surface of the lid 12.

  Further, as shown in FIG. 2, the lower surface of the first electrode sheet 13a of the electricity storage element 13 is electrically connected to the upper surface of the current collecting film 19 through the conductive adhesive layer 20, and the upper surface of the second electrode sheet 13b. Is electrically connected to the lower surface of the lid 12 through the conductive adhesive layer 21. The conductive adhesive layers 20 and 21 are a cured product of a conductive adhesive, and the conductive adhesive is preferably a thermosetting adhesive containing conductive particles, for example, an epoxy containing graphite particles. A system adhesive can be used.

  Here, with respect to the method of disposing the power storage element 13, (1) the case where the first electrode sheet 13a, the second electrode sheet 13b, and the separate sheet 13c are not manufactured as an integral object, and (2) the first electrode sheet 13a The case where the second electrode sheet 13b and the separate sheet 13c are manufactured as an integrated body will be described as an example.

  In the case of (1), as shown in FIGS. 4 (A) and 4 (B), an uncured conductive adhesive 20 ′ is applied to the surface of the current collector film 19, and the conductive adhesion is performed. The lower surface of the first electrode sheet 13a is relatively pressed against and closely adhered to the agent 20 ′ to cure the conductive adhesive. Then, a separate sheet 13c is placed on the upper surface of the first electrode sheet 13a. Before and after this, the same uncured conductive adhesive as described above was applied to the lower surface of the lid 12, and the upper surface of the second electrode sheet 13b was relatively pressed against and adhered to the conductive adhesive. The adhesive is cured. Then, the outer peripheral portion of the lower surface of the lid 12 is overlaid on the upper surface of the coupling ring 18, and at the same time, the lower surface of the second electrode sheet 13b is overlaid on the upper surface of the separate sheet 13c. Then, the lid 12 is coupled to the coupling ring 18.

  In the case of (2), as shown in FIGS. 4 (A) and 4 (B), an uncured conductive adhesive 20 ′ is applied to the surface of the current collector film 19, and The lower surface of the first electrode sheet 13a of the monolith (electric storage element 13) is pressed against the adhesive 20 'to be brought into close contact therewith. Then, the same uncured conductive adhesive as described above is applied to the lower surface of the lid 12, and the conductive adhesive is pressed against the upper surface of the second electrode sheet 13b of the monolith (electric storage element 13) to be brought into close contact therewith. Curing of the conductive adhesive is performed individually or collectively (simultaneously). Then, the lid 12 is coupled to the coupling ring 18.

  In any of the arrangement methods, since the lower surface of the first electrode sheet 13a is pressed against the uncured conductive adhesive 20 ′, the pressing is performed as shown in FIGS. 2 and 4B. In the process, at least the tip of each convex portion 19a of the current collecting film 19 bites into the lower surface of the first electrode sheet 13a, and a total of three concave portions 13a1 corresponding to the biting are formed on the lower surface of the first electrode sheet 13a.

  Since the first electrode sheet 13a made of an active material such as activated carbon or PAS (polyacene semiconductor) is not so hard, for example, when the height H19a of the convex portion 19a shown in FIG. 4A is about 50 μm. If the pressing force in the pressing process is about 0.3 MPa, each convex portion 19a can be sufficiently bite into the lower surface of the first electrode sheet 13a. Of course, the depth D13a1 of the recess 13a1 shown in FIG. 4B can be changed by changing the amount of pressing in the pressing process.

  Further, the thickness T20 ′ of the uncured conductive adhesive 20 ′ shown in FIG. 4A before the pressing process is reduced to the thickness T20 shown in FIG. 4B after the pressing process. However, the thickness T20 after the pressing process can be adjusted by changing the pressing amount. That is, only the tip portion of each convex portion 19a bites into the lower surface of the first electrode sheet 13a, and a conductive adhesive layer having a predetermined thickness between the upper surface of the current collector film 19 and the lower surface of the first electrode sheet 13a. If a gap in which 20 is interposed is secured, a necessary and sufficient amount of the conductive adhesive layer 20 (conductive adhesive 20 ′) can be left in the gap.

  Incidentally, FIG. 2 and FIG. 4 (B) show that the surface of the convex portion 19a and the inner surface of the concave portion 13a1 are slightly separated from each other, but this is the difference between the surface of the convex portion 19a and the inner surface of the concave portion 13a1. This is because the conductive particles in the conductive adhesive 20 ′ are sandwiched between them. Of course, in the state where the conductive particles are not sandwiched between the surface (particularly the apex) of the convex part 19a and the inner surface (particularly the deepest part) of the concave part 13a1, the vertex of the convex part 19a and the deepest part of the concave part 13a1 are directly Can make contact.

<Effects obtained by electrochemical device (first embodiment)>
According to the electrochemical device, the following (Effect 1) to (Effect 3) can be obtained.

  (Effect 1) The tip portions of a total of three convex portions 19a formed on the upper surface of the current collector film 19 are biting into the lower surface of the first electrode sheet 13a of the power storage element 13, and the electric power stored in the closed concave portion 11a is caused by the biting. Since the arrangement position of the element 13 can be determined, it is possible to reliably prevent a positional deviation that may occur in the step of arranging the power storage element 13 or a positional deviation that may occur when an impact is applied to the electrochemical device 10 before and after mounting. As a result, it is possible to avoid problems such as an increase in resistance value caused by the disposition of the storage element 13 being different from the intended position (position determined by design) and to prevent deterioration of charge / discharge characteristics.

  (Effect 2) Since the number of the convex portions 19a formed on the upper surface of the current collecting film 19 is three and the positions of the respective convex portions 19a are different on the upper surface of the current collecting film 19, the storage element is obtained by three-point biting. It is possible to accurately prevent misalignment, specifically linear displacement, rotational displacement, and tilt displacement, that may occur in the step of disposing 13. Moreover, since the attitude | position of the electrical storage element 13 can be stabilized by three-point support, the position shift which may arise when the impact is applied to the electrochemical device 10 before and behind mounting can be prevented further reliably.

  (Effect 3) By having only the tip part of each convex part 19a bite into the lower surface of the first electrode sheet 13a, a conductive material having a predetermined thickness between the upper surface of the current collector film 19 and the lower surface of the first electrode sheet 13a. Since a gap in which the adhesive layer 20 is interposed can be secured, a necessary and sufficient amount of the conductive adhesive layer 20 (conductive adhesive 20 ′) can be left in the gap, whereby the conductive adhesive layer 20 (conductive) It is possible to reliably avoid the problem that the amount of the adhesive 20 ′) is insufficient and the area between the upper surface of the current collector film 19 and the lower surface of the first electrode sheet 13a is insufficiently bonded and insufficient in strength.

[Second Embodiment]
FIG. 5 shows an electrochemical device (second embodiment) to which the present invention is applied. The electrochemical device shown in FIG. 5 is different from the electrochemical device 10 described in the first embodiment.
A total of three convex portions 12 a that protrude downward from the lower surface are formed on the lower surface of the lid 12 at different positions on the lower surface of the lid 12. At least the tip portion of each convex portion 12 a is the power storage element 13. The second electrode sheet 13b bites into the upper surface of the second electrode sheet 13b, and a recess 13b1 corresponding to the bite is formed on the upper surface of the second electrode sheet 13b. Other configurations and the arrangement method of the electricity storage element 13 are the same as those of the electrochemical device 10 described in the above [first embodiment].

  Each convex portion 12a is formed by locally pressing the center portion of the lid 12, and each lower end has a substantially hemispherical shape.

  Since the second electrode sheet 13b made of an active material such as activated carbon or PAS (polyacene semiconductor) is not so hard, for example, when the height of the convex portion 12a is about 50 μm, the pressing force in the pressing process is If it is about 0.3 MPa, each convex part 12a can be made to fully bite into the upper surface of the 2nd electrode sheet 13b. Of course, the depth of the recess 13b1 can be changed by changing the amount of pressing in the pressing process.

  Although the thickness of the uncured conductive adhesive before the pressing process decreases after the pressing process, the thickness after the pressing process can be adjusted by changing the amount of pressing. That is, only the tip portion of each convex portion 12a bites into the upper surface of the second electrode sheet 13b, and the conductive adhesive layer 21 having a predetermined thickness is formed between the lower surface of the lid 12 and the upper surface of the second electrode sheet 13b. If the intervening gap is secured, a necessary and sufficient amount of the conductive adhesive layer 21 (conductive adhesive) can be left in the gap.

  Incidentally, FIG. 5 shows that the surface of the convex portion 12a and the inner surface of the concave portion 13b1 are slightly separated, but this is a conductive adhesive between the surface of the convex portion 12a and the inner surface of the concave portion 13b1. This is because the conductive particles inside are sandwiched. Of course, in the state where the conductive particles are not sandwiched between the surface (particularly the apex) of the convex part 12a and the inner surface (particularly the deepest part) of the concave part 13b1, the vertex of the convex part 12a and the deepest part of the concave part 13b1 are directly Can make contact.

<Effects obtained by electrochemical device (second embodiment)>
According to the electrochemical device, in addition to (Effect 1) to (Effect 3) described in [First Embodiment], the following (Effect 4) to (Effect 6) can be obtained synergistically. .

  (Effect 4) The tip portions of a total of three convex portions 12a formed on the lower surface of the lid 12 bite into the upper surface of the second electrode sheet 13b of the electric storage element 13, and the electric storage element 13 in the closed concave portion 11a by the bite. Therefore, it is possible to reliably prevent misalignment that may occur in the step of disposing the storage element 13 or misalignment that may occur when an impact is applied to the electrochemical device before and after mounting. It is possible to prevent the deterioration of the charge / discharge characteristics by avoiding problems such as an increase in resistance value caused by the disposition of the storage element 13 being different from the intended position (position determined by design).

  (Effect 5) Since the number of the convex portions 12a formed on the lower surface of the lid 12 is three and the positions of the convex portions 12a are different on the lower surface of the lid 12, the power storage element 13 is arranged by three-point biting. It is possible to accurately prevent misalignment that can occur in the process, specifically, linear displacement, rotational displacement, and tilt displacement. Moreover, since the attitude | position of the electrical storage element 13 can be stabilized by three-point support, the position shift which may arise when an impact is added to the electrochemical device before and behind mounting can be prevented further reliably.

  (Effect 6) A conductive adhesive layer having a predetermined thickness between the lower surface of the lid 12 and the upper surface of the second electrode sheet 13b by causing only the tip portion of each convex portion 12a to bite into the upper surface of the second electrode sheet 13b. Since the gap where 21 is interposed can be secured, a necessary and sufficient amount of the conductive adhesive layer 21 (conductive adhesive) can be left in the gap, and thus the conductive adhesive layer 21 (conductive adhesive) It is possible to surely avoid the problem that the amount is insufficient and the bonding between the lower surface of the lid 12 and the upper surface of the second electrode sheet 13b causes insufficient area or insufficient strength.

[Third Embodiment]
FIG. 6 shows an electrochemical device (third embodiment) to which the present invention is applied. The electrochemical device shown in FIG. 6 is different from the electrochemical device 10 described in the first embodiment.
A point where each of the columnar portions 16 ′ of the positive electrode wiring 16 does not protrude upward from the bottom surface of the concave portion 11a. A point where no convex portion is formed on the upper surface of the current collecting film 19 other,
A total of three convex portions 12 a that protrude downward from the lower surface are formed on the lower surface of the lid 12 at different positions on the lower surface of the lid 12. At least the tip portion of each convex portion 12 a is the power storage element 13. The second electrode sheet 13b bites into the upper surface of the second electrode sheet 13b, and a recess 13b1 corresponding to the bite is formed on the upper surface of the second electrode sheet 13b. Other configurations and the arrangement method of the electricity storage element 13 are the same as those of the electrochemical device 10 described in the above [first embodiment]. Further, since the latter two differences are as described in the above [Second Embodiment], description thereof is omitted here.

<Effects obtained by electrochemical device (third embodiment)>
According to the electrochemical device, (Effect 4) to (Effect 6) described in the [Second Embodiment] can be obtained.

[Other Embodiments]
(1) In the [first embodiment] and the [second embodiment], the total number of the convex portions 19a formed on the upper surface of the current collector film 19 is three. The same effect as (Effect 1) to (Effect 3) can be obtained even if the total number of the projections is four or more, and (Effect 1) and (Effect 3) even if the number of the convex portions 19a is two or one. ). Moreover, although the hemispherical thing was shown as the convex part 19a, the shape of this convex part 19a is good also as shapes other than hemispherical shape, for example, cylindrical shape, a cone shape, etc.

  (2) In the above [Second Embodiment] and [Third Embodiment], the total number of the convex portions 12a formed on the lower surface of the lid 12 has been described, but the number of the convex portions 12a is described. Even if the total number is four or more, the same effects as (Effect 4) to (Effect 6) can be obtained, and even if the number of the convex portions 12a is two or one (Effect 4) and The same effect can be obtained. Moreover, although the hemispherical thing was shown as the convex part 12a, the shape of this convex part 12a is good also as shapes other than hemispherical shape, for example, cylindrical shape, a cone shape, etc.

  (3) In the above [first embodiment] and [second embodiment], the convex portion 19a is formed on the upper surface of the current collecting film 19 by using the upper end protruding portion of each columnar portion 16b of the positive electrode wiring 16. As shown in the third embodiment, each columnar portion 16 ′ of the positive electrode wiring 16 has a tip that does not protrude upward from the bottom surface of the recess 11a as in the third embodiment. If a substitute is formed on the bottom surface of the concave portion 11a, the convex portion 19a can be formed on the upper surface of the current collecting film 19 using the substitute. Of course, instead of using such a substitute, a locally raised portion may be formed on the current collecting film 19 itself, and this may be used as the convex portion 19a, or a convex portion on the upper surface of the current collecting film 19 may be used. A substitute may be retrofitted and used as the convex portion 19a.

  (4) In the [Second Embodiment] and [Third Embodiment], the convex portion 12a is integrally formed by locally pressing the central portion of the lid 12, but this is the case. Without performing a pressing process, a substitute for the convex portion may be retrofitted to the lower surface of the lid 12 and used as the convex portion 12a.

  The present invention can be widely applied to various electrochemical devices using chargeable / dischargeable storage elements, such as electric double layer capacitors, lithium ion capacitors, redox capacitors, lithium ion batteries, and the like. Can achieve the purpose described in

  DESCRIPTION OF SYMBOLS 10 ... Electrochemical device, 11 ... Case, 11a ... Recessed part, 12 ... Lid, 12a ... Convex part, 13 ... Power storage element, 13a ... 1st electrode sheet, 13a1 ... Recessed part, 13b ... 2nd electrode sheet, 13b1 ... Recessed part, 19 ... current collecting film, 19a ... convex portion.

Claims (7)

A case having a recess in the opening;
A lid that is coupled to the opening side of the case and forms a closed portion with the recess;
A current collector film provided on the bottom surface of the closed portion;
A chargeable / dischargeable energy storage device enclosed in the closed portion,
A first conductive adhesive layer disposed between the current collector film and the power storage element and electrically connecting the current collector film and the power storage element;
A second conductive adhesive layer disposed between the lid and the power storage element and electrically connecting the lid and the power storage element;
An electrochemical device having a tip portion that bites into the power storage element, and comprising at least one convex portion formed on at least one of the current collector film and the lid and protruding toward the power storage element. The electrochemical device according to claim 1,
The electrochemical device, wherein the convex portion is formed on the current collecting film, and at least a tip portion of the convex portion bites into the power storage element. The electrochemical device according to claim 2,
The number of the convex portions is three or more, and the position of each convex portion is different on the current collecting film. The electrochemical device according to claim 2 or 3,
The convex portion bites only the tip portion of the convex portion into the electric storage element so that a gap is interposed between the current collecting film and the electric storage element with the first conductive adhesive layer having a predetermined thickness. Electrochemical device. The electrochemical device according to any one of claims 1 to 4,
The electrochemical device, wherein the convex portion is formed on the lid, and at least a tip portion of the convex portion bites into the power storage element. The electrochemical device according to claim 5,
The number of the convex portions is three or more, and the positions of the convex portions are different on the lid. The electrochemical device according to claim 5 or 6,
The convex portion bites only the tip portion of the convex portion into the electric storage element so as to secure a gap in which the second conductive adhesive layer having a predetermined thickness is interposed between the lid and the electric storage element. Electrochemical device.

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