JP2015069962A - Power storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage element in which reduction in joint strength of an exterior can be suppressed.SOLUTION: This battery 100 (power storage element) includes an exterior 1 formed of a laminate film and including an upper surface part 10 and a lower surface part 11 which are substantially flat. The exterior 1 further includes: a sealing part A; and extension parts 16 and 17 extending from the sealing part A. In at least a part of the extension parts 16 and 17, a sealing part B1 is formed, respectively.

Description

  The present invention relates to a power storage element, and more particularly, to a power storage element including an exterior body made of a laminate film.

  2. Description of the Related Art Conventionally, an electricity storage element including an exterior body made of a laminate film is known (see, for example, Patent Document 1).

  Patent Document 1 discloses an upper exterior member and a lower exterior member (exterior body) made of a laminate material, a power generation element and an electrolyte disposed in a space formed by the upper exterior member and the lower exterior member, and a power generation element. And a terminal that is connected to the terminal and exposed to the outside from the end portions of the upper exterior member and the lower exterior member. In this thin battery, the upper exterior member and the lower exterior member are sealed by heat-sealing at the end portions.

JP 2006-324143 A

  However, as described above, in the thin battery of Patent Document 1, the upper exterior member and the lower exterior member are heat-sealed at the ends. Here, at the time of manufacturing a thin battery, if an electrolytic solution adheres to the end portion, thermal fusion tends to be incomplete. As a result, there is a problem that the bonding strength between the upper exterior member and the lower exterior member is likely to decrease.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a power storage device capable of suppressing a decrease in bonding strength of an exterior body. It is.

  An electricity storage element according to one aspect of the present invention includes a laminate film and includes an exterior body including a pair of substantially flat surface portions, and the exterior body includes a first sealing portion and an extension portion extending from the first sealing portion. The second sealing part is formed in at least a part of the extension part.

  In the electricity storage device according to one aspect of the present invention, the exterior body is provided with the first sealing portion and the second sealing portion formed on at least a part of the extension extending from the first sealing portion, Since the exterior body can be sealed not only in the first sealing portion but also in the second sealing portion formed in the extended portion extending from the first sealing portion, the bonding strength is reduced in the first sealing portion. Even in this case, the sealing of the exterior body can be maintained in the second sealing portion. Thereby, it can suppress that the joint strength of an exterior body falls.

  In the electricity storage device according to the above aspect, preferably further includes a sealing member having a fusion surface, and the extension portion includes a first extension portion extending from one surface portion, and a second extension portion extending from the other surface portion. The second sealing portion includes a surface of the first extension portion extending from the inner surface of the one surface portion and a surface of the second extension portion extending from the inner surface of the other surface portion, respectively. It is formed by being joined to the landing surface. If comprised in this way, compared with the case where the electrolyte solution adheres and the inner surfaces of the exterior body where the adhesive strength is likely to be reduced are joined together, the exterior body is a separate member, and the adhesive strength of the fusion surface is reduced Since the 2nd sealing part can be formed in an exterior body using the sealing member which is not, the joining state of the 2nd sealing part can be strengthened more. As a result, the exterior body can be sealed more reliably, so that the bonding strength of the exterior body can be improved.

  In this case, preferably, the first extension part and the second extension part are both folded back, and the sealing member is disposed so as to cover the folded back first extension part and second extension part. Yes. If comprised in this way, it will suppress that the 1st extension part and the 2nd extension part extend in the direction away from the 1st sealing part by turning up the 1st extension part and the 2nd extension part. Therefore, it can suppress that an electrical storage element becomes large in the direction which leaves | separates from a 1st sealing part. Moreover, since the sealing member is located outside the first extension portion and the second extension portion, the first extension portion and the second extension portion are covered by the sealing member that covers the first extension portion and the second extension portion. The boundary of the exterior body located between the extension portions can be protected. Thereby, the sealing by a sealing member can be made more reliable.

  In the configuration including the sealing member, preferably, a terminal further exposed to the outside from the first sealing portion in a state where the periphery is covered with the insulating member, and the sealing member includes the insulating member in the first sealing portion. It arrange | positions so that at least one part of the boundary with an exterior body may be covered from the outer side. If comprised in this way, since at least one part of the boundary of the insulating member and exterior body which joint strength tends to fall compared with the other boundary of a 1st sealing part can be covered with a sealing member from an outer side, sealing The sealing by the member can be further ensured.

  In the configuration including the terminal covered with the insulating member, the sealing member preferably further includes a slit into which the terminal is inserted, and the terminal is inserted into the slit. If comprised in this way, in the circumference | surroundings of the terminal inserted in the slit, the boundary of an insulating member and an exterior body and the boundary of exterior bodies can be easily covered from the outer side by a sealing member.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical storage element which can suppress that the joint strength of an exterior body falls as mentioned above can be obtained.

1 is a perspective view illustrating an overall configuration of a battery according to an embodiment of the present invention. It is the side view which showed the whole structure of the battery by one Embodiment of this invention. It is sectional drawing of the battery along the 500-500 line | wire of FIG. FIG. 5 is a cross-sectional view of the battery taken along line 510-510 in FIG. 1 is an exploded perspective view showing an overall configuration of a battery according to an embodiment of the present invention. It is a cross-sectional enlarged view of the positive electrode terminal vicinity of the battery by one Embodiment of this invention. It is a side view at the time of forming the sealing part A in the manufacturing method of the battery by one Embodiment of this invention. It is a side view at the time of forming sealing part B1 in the manufacturing method of the battery by one Embodiment of this invention. It is the side view which showed the structure of the terminal periphery of the battery by the 1st modification of one Embodiment of this invention. It is the side view which showed the structure of the terminal periphery of the battery by the 2nd modification of one Embodiment of this invention.

  First, a configuration of a battery 100 according to an embodiment of the present invention will be described with reference to FIGS. The battery 100 is an example of the “storage element” in the present invention.

  As shown in FIGS. 1 and 2, a battery 100 according to an embodiment of the present invention is a relatively large-capacity medium- or large-sized lithium ion battery having a discharge capacity of 10 Ah or more, and has a cylindrical shape made of a laminate film. An exterior body 1, a positive electrode terminal 2 and a negative electrode terminal 3 extending outward from the interior of the exterior body 1, and a pair of sealing members 4 made of the same laminate film as the exterior body 1 are provided. As shown in FIG. 2, a part of the positive electrode terminal 2 and a part of the negative electrode terminal 3, the power generation element 5, and an electrolyte solution (not shown) are accommodated in the cylindrical exterior body 1. The pair of sealing members 4 have a U-shaped bent shape, and are arranged so as to sandwich the end portion on the Y1 side and the end portion on the Y2 side in the longitudinal direction (Y direction) of the exterior body 1. Yes. Moreover, as shown in FIG. 3, the part including the joining location with the exterior body 1 among the positive electrode terminal 2 and the negative electrode terminal 3 is covered with the tab film 6 which has insulation and heat-fusion property. The positive electrode terminal 2 and the negative electrode terminal 3 are joined to the exterior body 1 through the tab film 6. The positive electrode terminal 2 and the negative electrode terminal 3 are examples of the “terminal” in the present invention, and the tab film 6 is an example of the “insulating member” in the present invention.

  In the battery 100 of the present embodiment, the structures of both end portions on the Y1 side and the Y2 side in the longitudinal direction (Y direction) are only differences regarding positive and negative polarities, and are structurally similar. For this reason, in the drawings, the same structure is denoted by the same reference numeral, and hereinafter, the structure on the positive electrode terminal 2 side (Y1 side) will be described, and the description on the negative electrode terminal 3 side (Y2 side) will be omitted unless necessary. To do.

  The laminate film constituting the exterior body 1 has a three-layer laminate structure in which a PE fusion layer 1a made of polyethylene, a metal layer 1b made of aluminum, and a PET protective layer 1c made of polyethylene terephthalate are laminated. Yes. Further, the laminate film constituting the sealing member 4 also has a three-layer laminate structure in which a PE fusion layer 4a, a metal layer 4b, and a PET protective layer 4c are laminated, as with the exterior body 1. . The PE fusion layers 1a and 4a both have a function of being melted by heat and joined (fused) to each other, and also have a function of insulating the metal layers 1b and 4b from the power generation element 5 and the like. Yes. In addition, the metal layers 1b and 4b have a function of suppressing entry of water from the outside. The PET protective layers 1c and 4c have functions of protecting and insulating the metal layers 1b and 4b.

  The exterior body 1 is formed in a flat cylindrical shape extending in the longitudinal direction (Y direction) as shown in FIG. 1 by bending one rectangular laminate film in half. Thereby, while the substantially flat upper surface part 10 is arrange | positioned at the one side (Z1 side) of the up-down direction (Z direction) of the cylindrical exterior body 1, the other side (Z2) of the up-down direction of the exterior body 1 is provided. The substantially flat lower surface portion 11 is disposed on the side. In addition, a side surface portion 12 that connects the upper surface portion 10 and the lower surface portion 11 is disposed on one side (X1 side) of the side portion extending in the longitudinal direction of the exterior body 1 and extends in the longitudinal direction of the exterior body 1. On the other side (X2 side) of the side part, a side surface joining part 13 joined (fused) in a state where the side end parts of the laminate film overlap each other is disposed.

  Here, as shown in FIGS. 3 and 4, in the outer package 1 formed in a cylindrical shape, the PE fusion layer 1 a of the laminate film is on the inner surface 1 d (10 a and 11 a) side of the outer package 1 (the power generation element 5 is The PET protective layer 1c of the laminate film is disposed so as to be positioned on the outer surface 1e side of the exterior body 1. Further, as shown in FIG. 1, the positive electrode terminal 2 and the negative electrode terminal 3 are respectively extended in the longitudinal direction (Y direction) from the end portions (both ends in the Y direction) extending in the short direction (X direction) of the exterior body 1. Along the outside. The positive electrode terminal 2 and the negative electrode terminal 3 are both led out from the approximate center in the short direction of the outer package 1. The upper surface portion 10 and the lower surface portion 11 are examples of the “surface portion” in the present invention.

  As shown in FIG. 2, Y1 extends from the upper surface portion 10 to join and seal the end portion of the tubular exterior body 1 on one side (Y1 side) in the longitudinal direction (Y direction) of the exterior body 1. A sealing region 14 extending to the side and a sealing region 15 extending from the lower surface portion 11 to the Y1 side are formed. By joining the sealing region 14 and the sealing region 15, the end portion extending in the short direction of the exterior body 1 is sealed to form the sealing portion A. At this time, the surface 14a of the sealing region 14 on the side of the PE fusion layer 1a and the surface 15a of the sealing region 15 on the side of the PE fusion layer 1a are heat-sealed with each other in a state of facing each other. Are joined to each other. Here, as shown in FIGS. 3 and 4, the surface 14 a on the PE fusion layer 1 a side of the sealing region 14 is formed so as to extend from the inner surface 10 a of the upper surface portion 10, and the PE melting of the sealing region 15 is performed. The surface 15 a on the side of the wearing layer 1 a is formed so as to extend from the inner surface 11 a of the lower surface portion 11. Further, the central portion of the sealing portion A in the X direction is sealed with the positive electrode terminal 2 interposed therebetween. The detailed structure will be described later. Further, the sealing portion A is an example of the “first sealing portion” in the present invention.

  Here, in the present embodiment, as shown in FIG. 5, the exterior body 1 is formed with extensions 16 and 17 that further extend from the sealing regions 14 and 15, respectively. The extension portion 16 is folded along the sealing portion A in the direction toward the upper surface portion 10. Further, the extension portion 17 is folded along the sealing portion A in the direction toward the lower surface portion 11. As a result, the surface 16a (see FIG. 3) on the PE fusion layer 1a side of the extension 16 and the surface 17a (see FIG. 3) on the PE fusion layer 1a side of the extension 17 are respectively outside (upper and (Lower side). The surface 16a on the PE fusion layer 1a side of the extension portion 16 is formed so as to extend from the inner surface 10a of the upper surface portion 10 continuously to the surface 14a of the sealing region 14, and the PE melt of the extension portion 17 is also formed. The surface 17 a on the side of the wearing layer 1 a is formed so as to extend from the inner surface 11 a of the lower surface portion 11 continuously to the surface 15 a of the sealing region 15. The extension parts 16 and 17 are arranged so as to cover a sealing member 4 described later. The extensions 16 and 17 are examples of the “first extension” and the “second extension” in the present invention, respectively.

  As shown in FIGS. 1 and 2, the positive electrode terminal 2 is a flat metal part made of aluminum, and is exposed to the outside (Y1 side) from the sealing portion A on the Y1 side and the sealing member 4. The negative electrode terminal 3 is a flat metal part made of copper or copper plated with nickel, and is exposed to the outside (Y2 side) from the sealing portion A and the sealing member 4 on the Y2 side. In the positive electrode terminal 2, a part including a joint portion with the exterior body 1 is covered with the tab film 6, and the tab film 6 and the positive electrode terminal 2 are in close contact with each other. The tab film 6 is made of a resin (polypropylene (PP)) and has an insulating property, and suppresses conduction between the positive electrode terminal 2 and the outer package 1. Further, the tab film 6 also has a heat fusion property with the PE fusion bonding layer 1 a of the outer package 1. Thereby, the positive electrode terminal 2 and the sealing regions 14 and 15 of the exterior body 1 are joined via the tab film 6. The negative electrode terminal 2 has the same structure and will not be described.

  As shown in FIG. 6, both the plate-like positive electrode terminal 2 and the negative electrode terminal 3 have a thickness t1 in the Z direction and a width W1 in the X direction, and the Y direction (see FIG. 5). It is formed in a rectangular shape in an enlarged view seen from the above. Further, the outer peripheral portion of the tab film 6 is formed in a rectangular shape when viewed from the Y direction, and has a dimension t2 in the Z direction (terminal thickness direction) and a dimension W2 in the X direction (terminal width direction). have. In addition, the dimension t2 and W2 of the outer peripheral part of the tab film 6 are larger than the thickness t1 and the width W1 of the positive electrode terminal 2 and the negative electrode terminal 3, respectively.

  As shown in FIG. 3, the sealing regions 14 and 15 and the tab film 6 are joined to each other at the center in the X direction (see FIG. 1). At this time, the PE fusion layer 1a (see FIG. 3) in the sealing regions 14 and 15 and the resin on the outer peripheral surface of the tab film 6 are bonded to each other by thermal fusion. Moreover, as shown in FIG. 4, the sealing area | region 14 and the sealing area | region 15 are mutually joined in parts (refer FIG. 1) other than the center part of a X direction.

  Thus, the exterior body 1 is sealed over the entire X direction with the positive electrode terminal 2 sandwiched in the sealing portion A, and is sealed over a predetermined length in the Y direction. .

  A boundary C1 is formed between the tab film 6 and the exterior body 1 (sealing regions 14 and 15) joined together, and a boundary is formed between the sealing region 14 and the sealing region 15 joined together. C2 is formed. The boundary C1 is a portion where the PE fusion layer 1a of the outer package 1 and the resin of the tab film 6 are bonded by heat fusion, and the boundary C2 is the heat between the PE fusion layers 1a in the sealing regions 14 and 15. It is the part that is fused and joined. Here, when the electrolytic solution adheres to the sealing region 14 or 15 and the sealing portion A is not sufficiently joined, an opening may occur at the corresponding portion of the sealing portion A, and the electrolyte leaks. There is a risk of malfunctions.

  As shown in FIG. 5, the sealing member 4 is formed in a U shape as seen from the X direction by folding a single laminate film so that the main body side (power generation element 5 side) of the battery 100 is a valley. ing. At this time, as shown in FIGS. 3 and 4, the sealing member 4 has the PE fusion layer 4a located on the U-shaped valley side surface 4d and the PET protective layer 4c located on the mountain side surface 4e. It is formed as follows. The valley-side surface 4d on which the PE fusion layer 4a is disposed is an example of the “fusion surface” in the present invention.

  Further, as shown in FIG. 5, a slit 41 penetrating the sealing member 4 is formed in a bent portion at a substantially center of the sealing member 4. The slit 41 is formed in a rectangular shape when viewed from the Y direction, and is configured such that the positive electrode terminal 2 is inserted therein. As shown in FIG. 6, the slit 41 has a dimension t3 in the Z direction and a dimension W3 in the X direction. Here, the dimension t3 of the slit 41 is larger than the thickness t1 of the positive electrode terminal 2 and smaller than the dimension t2 of the outer peripheral portion of the tab film 6. The dimension W3 of the slit 41 is larger than the width W1 of the positive electrode terminal 2 and smaller than the dimension W2 of the outer peripheral portion of the tab film 6. As a result, the slit 41 is formed so that the positive electrode terminal 2 can be inserted, while the tab film 6 is not inserted.

  Moreover, in this embodiment, as shown in FIG. 2, the sealing member 4 is arrange | positioned at the exterior body 1 from the Y1 side so that the extended extensions 16 and 17 may be inserted | pinched. Thereby, the sealing member 4 on the Y1 side is arranged so as to cover the folded-back upper extension portion 16 from above (Z1 side) and to cover the folded-back lower extension portion 17 from below (Z1 side). ing. Further, the extension portion 16 and the sealing member 4 are joined to each other along the X direction, and the extension portion 17 and the sealing member 4 are joined to each other along the X direction, thereby forming the sealing portion B1. ing. At this time, as shown in FIG. 3 to FIG. 5, the PE fusion layer 4 a located on the inner surface 4 d of the sealing member 4 and the PE fusion layer 1 a on the surface 16 a of the extension 16 disposed so as to be exposed to the outside. The sealing member 4 and the extension portion 16 are joined to each other by heat-sealing with the two facing each other. Further, heat fusion is performed in a state where the PE fusion layer 4a located on the inner surface 4d of the sealing member 4 and the PE fusion layer 1a on the surface 17a of the extension portion 17 disposed so as to be exposed to the outside face each other. Thus, the sealing member 4 and the extension portion 17 are joined to each other. As described above, the exterior body 1 is also sealed over the entire length in the X direction and also over the predetermined length in the Y direction in the sealing portion B1. Further, the sealing portion B1 is continuously formed without being spaced from the sealing portion A. Thereby, it is possible to suppress the electrolyte from leaking from the gap between the sealing part A and the sealing part B1. The sealing portion B1 is an example of the “second sealing portion” in the present invention.

  Further, the positive electrode terminal 2 is inserted into the slit 41 in a state where the sealing member 4 and the extension portions 16 and 17 are joined. At this time, the slit 41 is formed so that the tab film 6 is not inserted, so that the sealing member 4 around the slit 41 is in contact with the tab film 6. As a result, the sealing member 4 is disposed so as to cover the boundary C1 between the tab film 6 and the exterior body 1 from the outside (Y1 side), and is fused to the PE film 1a of the tab film 6 and the exterior body 1. It is worn. Further, the sealing member 4 is disposed so as to cover the boundary C <b> 2 between the sealing region 14 and the sealing region 15 from the outside, and is fused to the PE fusion layer 1 a of the exterior body 1. As a result, the sealing member 4 is fused in a state of being disposed so as to cover the entire sealing portion A from the outside.

  Next, with reference to FIG. 1, FIG. 3, FIG. 7 and FIG. 8, a method of manufacturing the battery 100 according to an embodiment of the present invention will be described.

  First, a rectangular laminate film having a three-layer laminate structure in which a PE fusion layer 1a, a metal layer 1b, and a PET protective layer 1c (see FIG. 3) are laminated is prepared. At this time, a laminate film having a length that can secure the extension portions 16 and 17 on both sides in the longitudinal direction (Y direction) when formed into a cylindrical shape (excessively long by L4 × 2 (= about 20 mm) described later). Prepare. Then, the laminate film is bent in half so that the PE fusion layer 1a becomes the inner surface and a pair of opposing side end portions (side portions) overlap. The laminated film is formed in a cylindrical shape by heat-sealing and heat-sealing the stacked side end portions, and the exterior body 1 extending in the longitudinal direction (Y direction) is created. In addition, the side edge part heat-sealed becomes the side surface junction part 13. FIG.

  Next, a power generation element 5 formed in a flat shape, and a positive electrode terminal 2 and a negative electrode terminal 3 in which a part including a joint portion with the exterior body 1 is covered with a tab film 6 are prepared. The positive electrode terminal 2 is connected to one end on the positive electrode side (Y1 side), and the negative electrode terminal 3 is connected to the other end on the negative electrode side (Y2 side). Then, the power generation element 5 to which the positive electrode terminal 2 and the negative electrode terminal 3 are connected is disposed inside the exterior body 1.

  Thereafter, as shown in FIG. 7, the sealing regions 14 and 15 and the portion covered with the tab film 6 of the positive electrode terminal 2 are overlapped at the position of the length L4 (about 10 mm) from the end portion on the Y1 side. Perform heat sealing. Thereby, the sealing area | region 14, the sealing area | region 15, and the tab film 6 are joined in the location where the positive electrode terminal 2 of the center part of a X direction is pinched | interposed into the exterior body 1. FIG. Moreover, the sealing area | region 14 and the sealing area | region 15 are joined in the location where the positive electrode terminal 2 is not pinched. In this way, the sealing portion A on the Y1 side of the exterior body 1 is formed, and the extending portions 16 and 17 further extending from the sealing portion A are formed. At this time, the location where the positive electrode terminal 2 in the center in the X direction is sandwiched by the outer package 1 needs to be sandwiched between the outer package 1 and the outer package 1 as a result. A step is formed. In the stepped portion C3 (see FIG. 6) formed in the exterior body 1, a gap is generated. As shown in FIG. 6, the gap is filled and sealed when the melted PE fusion layer 1 a flows in when the sealing portion A is formed, but the stepped portion C <b> 3 is compared with other sealing portions A. , The sealing tends to be insufficient.

  And the extension parts 16 and 17 are wash | cleaned with a predetermined chemical | medical agent as needed. Thereafter, the extensions 16 and 17 are bent at substantially right angles. At this time, in order to bend the extension portions 16 and 17 easily, cuts (not shown) are formed in the side portions 12 on both sides in the short direction (X direction) as much as necessary for bending.

  Next, a laminate film having a three-layer laminate structure in which a PE fusion layer 4a, a metal layer 4b, and a PET protective layer 4c (see FIG. 3) are laminated, and a slit 41 is formed at the center. A flat plate-like sealing member 4 is prepared. Then, in a state where the positive electrode terminal 2 is inserted into the slit 41, the inner surface 4d of the sealing member 4 is disposed so as to face the surface 16a of the extension portion 16 and the surface 17a of the extension portion 17 bent at a right angle.

  Then, as shown in FIG. 8, heat sealing is performed so as to sandwich the sealing member 4 and the extension portion 16, and heat sealing is performed so as to sandwich the sealing member 4 and the extension portion 17. At this time, heat sealing is performed in a state where the vicinity of the tab film 6 is sandwiched by a jig (not shown). As a result, the PE fusion layer 1 a of the extension portion 16 and the PE fusion layer 4 a of the sealing member 4 are joined to form the sealing portion B 1 a in the exterior body 1. Further, the PE fusion layer 1 a of the extension portion 17 and the PE fusion layer 4 a of the sealing member 4 are joined to form the sealing portion B 1 b in the exterior body 1. The PE fusion layers 1a and 4a in the vicinity of the boundary C1 and in the vicinity of C2 are fused by the heat of bonding between the extension portion 16 and the sealing member 4 and the heat of bonding between the extension portion 17 and the sealing member 4. Thus, the sealing portion B1c is formed in the exterior body 1. Thereby, the sealing part B1 which consists of sealing part B1a, B1b, and B1c is continuously formed in the exterior body 1 without spacing apart from the sealing part A. Further, when the sealing member 4 around the slit 41 abuts against the tab film 6, the sealing member 4 has a boundary C1 between the tab film 6 and the exterior body 1 and a boundary C2 between the sealing regions 14 and 15 (see FIG. 4). ) Are covered from the outside (Y1 side). At this time, the step portion C3 (see FIG. 6) where the sealing tends to be insufficient is also fused in a state where the sealing member 4 is covered from the outside. Thereby, the sealing by the sealing member 4 is ensured.

  Then, the extension portion 16 and the sealing member 4 joined to the extension portion 16 are folded back along the sealing portion A in the direction toward the upper surface portion 10. Similarly, the extension part 17 and the sealing member 4 joined to the extension part 17 are folded back along the sealing part A in the direction toward the lower surface part 11. As a result, the sealing operation on the Y1 side of the exterior body 1 is completed.

  Then, after inject | pouring the electrolyte solution which is not shown in figure into the exterior body 1 from the Y2 side, the sealing operation similar to the Y1 side is also performed on the Y2 side. Thereby, the battery 100 shown in FIG. 1 is produced.

  In the present embodiment, as described above, the sealing regions 14 and 15 have the extension portions 16 and 17 further extending from the sealing portion A, respectively, and the sealing member 4 and the extension portion 16 are joined to each other, so that the sealing member 4 And the extension portion 17 are joined together to form the sealing portion B1. Thereby, since not only the sealing part A but also the sealing part B1 formed in the extension parts 16 and 17 extending from the sealing part A, the exterior body 1 can be sealed, so that the bonding strength is reduced in the sealing part A. Even if it is a case, the sealing of the exterior body 1 can be maintained in sealing part B1. As a result, since it can suppress that the joining strength of the exterior body 1 falls, it can suppress that electrolyte solution leaks out from the inside of the battery 100. FIG.

  In the present embodiment, since the sealing portion B1 is sealed after the sealing portion A is sealed, the extension portion 16 is sealed after the sealing portion A is sealed and before the sealing portion B1 is sealed. And 17 can be washed. As a result, even if foreign matter such as electrolyte solution adheres to the extension portions 16 and 17, the sealing portion B1 can be sealed with the foreign matter removed, so that the sealing of the sealing portion B1 is strengthened. Can do.

  In the present embodiment, the PE fusion layer 4a located on the inner surface 4d of the sealing member 4 and the PE fusion layer 1a on the surface 16a of the extension portion 16 disposed so as to be exposed to the outside face each other. The extension portion 16 and the sealing member 4 are joined to each other by heat-sealing. Further, the PE fusion layer 4a located on the inner surface 4d of the sealing member 4 and the PE fusion layer 1a on the surface 17a of the extension portion 17 disposed so as to be exposed to the outside are heat-sealed in a state of facing each other. By doing so, the extension part 17 and the sealing member 4 are joined to each other. As a result, the exterior body 1 is sealed at the sealing portion B1 in addition to the sealing portion A. Thereby, compared with the case where the inner surface 1d of the exterior body 1 which the electrolyte solution which is not shown in figure adheres and adhesive force falls easily is joined, the exterior body 1 is a different member, and PE fusion layer 4a of the inner surface 4d Since the sealing part B1 can be formed in the exterior body 1 using the sealing member 4 whose adhesive strength is not reduced, the bonding state of the sealing part B1 can be further strengthened. As a result, since the outer package 1 can be sealed more reliably, the bonding strength of the outer package 1 can be improved.

  In the present embodiment, the sealing member 4 is arranged so as to cover the folded upper extension 16 from above (Z1 side), and the folded lower extension 17 is arranged from below (Z1 side). Arrange to cover. Thus, by folding back the extension portions 16 and 17, the extension portions 16 and 17 can be prevented from extending in the longitudinal direction (Y direction) away from the sealing portion A, so that the battery 100 is separated from the sealing portion A in the longitudinal direction. It is possible to suppress an increase in the direction. Moreover, since the sealing member 4 can be joined in the wide area | region of the folded-back extension parts 16 and 17 by covering the extension parts 16 and 17 by which the sealing member 4 was folded back, the joint strength of sealing part B1 is made. It can be improved further. Furthermore, since the sealing member 4 is located outside the extension portions 16 and 17, the sealing member 4 causes the boundary C1 between the tab film 6 and the exterior body 1 positioned between the extension portion 16 and the extension portion 17 to be The boundary C2 between the exterior bodies 1 can be protected. Thereby, the sealing by the sealing member 4 can be made more reliable.

  Further, in the present embodiment, the sealing portion A can be protected from the external environment by covering the sealing portion A from the outside with the sealing member 4, and the sealing portion A can be reinforced by the sealing member 4.

  Moreover, in this embodiment, by arrange | positioning the sealing member 4 so that the boundary C1 of the tab film 6 and the exterior body 1 may be covered from the outer side, compared with the other boundary C2 of the sealing part A, joining strength falls. Since the boundary C1 between the easy tab film 6 and the exterior body 1 can be covered from the outside by the sealing member 4, the sealing by the sealing member 4 can be further ensured.

  Further, in the present embodiment, the positive electrode terminal 2 and the negative electrode terminal 3 are inserted into the slit 41 of the sealing member 4, so that the sealing member 4 has a tab around the positive electrode terminal 2 and the negative electrode terminal 3 inserted into the slit 41. The boundary C1 between the film 6 and the exterior body 1 and the boundary C2 between the sealing area 14 and the sealing area 15 (boundary between the exterior bodies 1) can be easily covered from the outside.

  Moreover, in this embodiment, while sealing the exterior body 1 over the whole X direction in the sealing part A, it seals over a predetermined length in the Y direction. Furthermore, the exterior body 1 is sealed over the entire length in the X direction at the sealing portion B1, and is sealed over a predetermined length in the Y direction. Thereby, in both of the sealing portions A and B1, the sealing can be performed over substantially the entire X direction, and the sealing can be performed for a predetermined length in the Y direction. The inside and outside of 1 can be shut off.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  In the said embodiment, although the example which formed sealing part B1 using the sealing member 4 was shown, this invention is not limited to this. In the present invention, the sealing member may not be used. For example, like the battery 200 of the first modification example of the present embodiment shown in FIG. 9, the extension portion 216 and the extension portion 217 of the exterior body 201 are joined in a state of facing each other without using a sealing member. The exterior body 201 may be sealed at the sealing portion B2. In this case, there is no need to fold back the extensions 216 and 217, so that the manufacturing process can be simplified. Furthermore, since it is not necessary to use a sealing member, the number of parts can be reduced. Moreover, it is preferable that the sealing part B2 is formed continuously without leaving a gap with the sealing part A. Thereby, it is possible to suppress the electrolyte from leaking from the gap between the sealing portion A and the sealing portion B2 (for example, the gap generated in the side surface bonding portion 13 of the laminate film). In addition, this sealing part B2 may be provided over the whole among X directions, and may be provided only in the location where a sealing tends to become inadequate. The extension portions 216 and 217 are examples of the “first extension portion” and the “second extension portion” of the present invention, respectively, and the sealing portion B2 is the “second sealing portion” of the present invention. It is an example. The battery 200 is an example of the “storage element” in the present invention.

  In the first modification, the joined extensions 216 and 217 may be folded back in any one of the Z directions. Thereby, it is possible to suppress an increase in size of the battery 200 in the longitudinal direction (Y direction).

  Moreover, in the said embodiment, although the extension parts 16 and 17 and the sealing member 4 were joined in the state folded up so that it might extend along the sealing part A, this invention showed this. Not limited to. In the present invention, the extension portion does not have to be folded back along the sealing portion A. For example, like the battery 300 of the second modified example of the present embodiment shown in FIG. 10, the extension portions 316 and 317 of the exterior body 301 may be configured not to be bent. The battery 300 is an example of the “power storage element” in the present invention, and the extensions 316 and 317 are examples of the “first extension” and the “second extension” in the present invention, respectively.

  Specifically, the extension portions 316 and 317 of the exterior body 301 are formed so as to extend in a direction away from the sealing portion A (Y1 direction), and the sealing member 304 is opposite to the exterior body 301. It is formed in a U shape having an opening on the side (Y1 side). At this time, the sealing member 304 is formed such that the U-shape is slightly collapsed in the vertical direction (Z direction). In this case, it is possible to suppress the battery 300 from increasing in the vertical direction (Z direction). Further, the extension portion 316 and the sealing member 304 are joined to each other, and the extension portion 317 and the sealing member 304 are joined to each other, whereby the exterior body 301 is sealed at the sealing portion B3. The sealing part B3 is an example of the “second sealing part” in the present invention.

  Moreover, although the example which provided the extension parts 16 and 17, respectively was shown in the said embodiment at the both sides of a longitudinal direction (Y direction), this invention is not limited to this. In the present invention, an extension may be provided only on the other side without providing an extension on one side in a predetermined direction (for example, the longitudinal direction).

  Moreover, although the example which made the structure of Y1 side and Y2 side the same was shown in the said embodiment, this invention is not limited to this. In the present invention, the structures on the Y1 side and the Y2 side may be different. For example, the Y1 side may have the configuration of the above-described embodiment (a configuration in which the Y1 side is folded and covered with a sealing member), and the Y2 side may have the configuration of the first modified example (a configuration that does not bend). In this case, since no sealing member is required on the Y2 side, the number of parts can be reduced.

  Moreover, in the said embodiment, although the example which has arrange | positioned the sealing member 4 so that the whole sealing part A (1st sealing part) might be covered from the outer side was shown, this invention is not limited to this. In the present invention, the sealing member may be arranged so as to cover only a part of the first sealing portion from the outside. At this time, it is preferable to arrange the sealing member so as to cover a portion near the injection hole for injecting the electrolytic solution or a portion where the sealing tends to be insufficient such as a boundary between the tab film and the sealing region from the outside.

  Moreover, in the said embodiment, although the positive electrode terminal 2 and the negative electrode terminal 3 were each derived | led-out from the edge part by the side of Y1 of the exterior body 1, and the edge part by the side of Y2, the present invention is not limited to this. . In the present invention, both the positive electrode terminal and the negative electrode terminal may be led out from one end of the exterior body. In that case, it is preferable to arrange the sealing member so as to cover both terminals.

  Moreover, in the said embodiment, although the example which each provided the sealing part and the extension part in the both ends of the longitudinal direction (Y direction) of the exterior body 1 was shown, this invention is not limited to this. In this invention, you may provide a sealing part and an extension part in the edge part of the transversal direction of an exterior body.

  Moreover, in the said embodiment, although the example which formed the laminate film in the cylinder shape was shown by bending the rectangular-shaped laminate film and heat-seal | fusing a side edge part, this invention is not limited to this. In the present invention, a tubular laminate film may be used. In this case, it is possible to omit the step of processing the rectangular laminate film into a cylindrical shape. In addition, since a gap cannot be formed at the side end portion of the tubular laminate film, the electrolyte does not leak from the side end portion. For this reason, when the tube-shaped laminate film is used in the first modified example, it is not necessary to continuously form the sealing portion B2 without being spaced from the sealing portion A.

  Moreover, in the said embodiment, while sealing part B1 provided in the extension parts 16 and 17 is sealed over the whole X direction, it seals over a predetermined length in the Y direction (the extension part 16 and Although an example in which a part of 17 is sealed) is shown, the present invention is not limited to this. In the present invention, for example, the sealing portion B1 may be sealed over substantially the entire X direction and substantially the entire Y direction. That is, the entire extension portions 16 and 17 may be sealed. Thereby, it is possible to make a sealing more reliable.

  Moreover, although the example which applies the electrical storage element of this invention to the lithium ion battery which is 1 type of a non-aqueous electrolyte battery was shown in the said embodiment, this invention is not limited to this. The power storage device of the present invention may be applied to, for example, a non-aqueous electrolyte battery other than a lithium ion battery, or may be applied to an aqueous electrolyte battery such as a nickel metal hydride battery.

1, 201, 301 exterior 1d, 10a, 11a inner surface 2 positive terminal (terminal)
3 Negative terminal (terminal)
4,304 Sealing member 4d Valley side surface (fused surface)
6 Tab film (insulating material)
10 Top surface (surface)
11 Lower surface (surface)
16, 216, 316 Extension (first extension)
16a Surface 17, 217, 317 Extension (second extension)
17a Surface 41 Slit 100, 200, 300 Battery (electric storage element)
A sealing part (first sealing part)
B1, B2, B3 Sealing part (second sealing part)

Claims (5)

It is made of a laminate film, and includes an exterior body including a pair of substantially flat surface portions,
The exterior body further includes a first sealing portion and an extension extending from the first sealing portion,
The electrical storage element in which the 2nd sealing part is formed in at least one part of the said extension part. A sealing member having a fusion surface;
The extension includes a first extension extending from one of the surface portions and a second extension extending from the other surface portion,
In the second sealing portion, the surface of the first extension portion extending from the inner surface of the one surface portion and the surface of the second extension portion extending from the inner surface of the other surface portion are respectively the sealing member. The electrical storage element according to claim 1, wherein the electrical storage element is formed by being bonded to the fusion surface. The first extension and the second extension are both folded back,
The power storage element according to claim 2, wherein the sealing member is disposed so as to cover the first extension portion and the second extension portion that are folded back. In a state where the periphery is covered with an insulating member, the terminal further includes a terminal exposed to the outside from the first sealing portion,
The power storage element according to claim 2 or 3, wherein the sealing member is disposed so as to cover at least a part of a boundary between the insulating member and the exterior body in the first sealing portion from the outside.   The power storage element according to claim 4, wherein the sealing member further includes a slit into which the terminal is inserted, and the terminal is inserted into the slit.

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