JP2010027494A - Electricity storage device, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electricity storage device with a structure capable of simplifying manufacturing processes of the electricity storage device such as a lithium ion secondary battery and preventing deterioration of characteristics of the electricity storage device, and to provide a manufacturing method thereof. <P>SOLUTION: A positive electrode connection terminal 30 and a negative electrode connection terminal of the lithium ion secondary battery each include a first connection terminal member 31 and a second connection terminal member 32 arranged to sandwich an outer package 20 and respective ends of positive electrodes or negative electrodes. The first connection terminal member 31 includes: bar-shaped sections 311, 312; and a connection plate section 314 for connecting the bar-shaped sections 311, 312, which is integrally formed at one side ends of the bar-shaped sections 311, 312. The second connection terminal member 32 is arranged to face the connection plate section 314, and has through-holes 321, 322, respectively. The other ends of the bar-shaped sections 311, 312 are inserted into and engaged to through-holes 321, 322. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electricity storage device such as a lithium ion secondary battery, a lithium secondary battery, a polymer secondary battery, and an electric double layer capacitor, and a method for producing the same.

  2. Description of the Related Art Conventionally, for power storage devices such as lithium ion secondary batteries, there are increasing demands for downsizing, weight reduction, thickness reduction, shape flexibility, and the like with the expansion of various applications.

  Therefore, in order to meet such demands, a laminate film having a multilayer structure has been conventionally used to form a flexible exterior body that houses a power storage element. The laminate film is composed of an inner surface layer facing the electricity storage element, an intermediate layer, and an outer surface layer facing the outside. The inner surface layer is made of, for example, a thermoplastic resin excellent in electrolytic solution resistance and heat sealability, such as polyethylene and polypropylene. An intermediate | middle layer consists of metal foil excellent in flexibility and intensity | strength, such as aluminum foil, for example. An outer surface layer consists of insulating resin excellent in electrical insulation, such as a polyamide-type resin, for example.

  Sheet-like lithium ions that are lightweight, thin, flexible, and can be reduced in size and weight by encapsulating a sheet-like internal electrode pair and an electrolyte in an outer package made of such a laminate film An electrode lead structure for a secondary battery is proposed in, for example, Japanese Patent Application Laid-Open No. 2003-151529 (hereinafter referred to as Patent Document 1).

  8 is a perspective view showing the sheet-like lithium ion secondary battery disclosed in Patent Document 1, and FIG. 9 is a partial cross-sectional view taken along line IX-IX in FIG. Although FIG. 9 shows a cross section on the positive electrode lead side, the negative electrode lead side is structurally the same as the positive electrode lead side. Below, it demonstrates centering on the positive electrode lead side.

  As shown in FIGS. 8 and 9, in the sheet-like lithium ion secondary battery 1000, a flexible bag-like outer package 1020 made of a laminate film is composed of an inner surface layer 1021, an intermediate layer 1022, and an outer surface layer 1023. Composed. The bag-like outer package 1020 includes a sheet-like internal electrode pair 1011 formed by alternately laminating a plurality of sheet-like positive electrodes and a plurality of sheet-like negative electrodes via separators, and an electrolyte solution. In a sealed state.

  Inside the bag-like outer package 1020, a positive-side internal lead 1032 that connects each positive electrode of the internal electrode pair 1011 and a negative-side internal lead (1042, not shown) that connects each negative electrode of the internal electrode pair 1011. Z) and are arranged. The external lead 1030 on the positive electrode side is disposed outside the bag-shaped outer package 1020 corresponding to the internal lead 1032 on the positive electrode side with the bag-shaped outer package 1020 interposed therebetween, and the external lead 1040 on the negative electrode side is disposed on the bag-shaped outer package 1020. Is disposed outside the bag-like outer package 1020 corresponding to the internal lead (1042) on the negative electrode side.

  The rivets 1031 and 1041 are arranged to electrically connect the internal leads 1032 and (1042) and the external leads 1030 and 1040, respectively. Specifically, each of the rivets 1031 and 1041 penetrates the bag-like outer package 1020 in an airtight manner, and one end side thereof is connected to the internal leads 1032 and (1042) located inside the bag-like outer package 1020. The other end is connected to external leads 1030 and 1040 located outside the bag-like outer package 1020.

Between the inner leads 1032 and (1042) and the bag-shaped outer package 1020 and between the outer leads 1030 and 1040 and the bag-shaped outer package 1020, the bag-shaped outer package 1020 penetrates the rivets 1031 and 1041. Seal members 1051 and 1052 for sealing the holes are interposed. A heat seal portion 1024 is formed around the bag-like outer package 1020.
JP 2003-151529 A

  However, the sheet-like lithium ion secondary battery disclosed in Patent Document 1 may cause the following problems.

  First, the rivets 1031 and 1041 are inserted into the through holes of the internal leads 1032 and 1042, the bag-like outer package 1020, and the external leads 1030 and 1040, and the tips of the protruding rivets 1031 and 1041 are inserted. It is necessary to perform a process of tightening. Since a plurality of rivets 1031 and 1041 as connecting means are provided, it is necessary to position each of the rivets 1031 and 1041 each time the above-described process is performed.

  Further, since the internal leads 1032 and (1042) and the rivets 1031 and 1041 or the external leads 1030 and 1040 and the rivets 1031 and 1041 are separate members, the contact resistance between these members is large, and the battery characteristics deteriorate. May end up.

  Accordingly, an object of the present invention is to simplify the manufacturing process of a power storage device such as a lithium ion secondary battery in view of the problems of the conventional technology as described above, and to prevent deterioration of characteristics of the power storage device. It is providing the electrical storage device which has the structure which can do, and its manufacturing method.

  An electricity storage device according to the present invention includes an exterior body that houses an electricity storage element, and a positive electrode connection terminal and a negative electrode connection terminal that are electrically connected to the positive electrode and the negative electrode of the electricity storage element, respectively. Each of the positive electrode connection terminal and the negative electrode connection terminal includes a first connection terminal member and a second connection terminal member that are disposed so as to sandwich the exterior body and the ends of each of the positive electrode and the negative electrode. The first connection terminal member includes a plurality of rod-shaped portions and a connecting portion that is integrally formed at one end of the plurality of rod-shaped portions and connects the plurality of rod-shaped portions. The second connection terminal member is disposed so as to face the coupling portion and has a plurality of through holes. The other end portions of the plurality of rod-shaped portions are inserted through and engaged with the plurality of through holes.

  In the electricity storage device of the present invention, since the first connection terminal member includes a connecting portion that is integrally formed at one end of the plurality of rod-shaped portions and connects the plurality of rod-shaped portions, the first connecting terminal member is connected by the connecting portion. It is possible to easily engage the other end portions of the plurality of rod-shaped portions simultaneously with each of the plurality of through holes of the second connection terminal member. Thereby, it is not necessary to position each of the plurality of bar-shaped members every time the step of caulking the tip of the bar-shaped member called a rivet as in the prior art, and the manufacturing process can be simplified.

  Further, since the plurality of rod-shaped portions and the coupling portion are integrally formed in the first connection terminal member, the contact resistance between the rod-shaped portion and the coupling portion is reduced, and the deterioration of the characteristics of the electricity storage device is prevented. be able to.

  In the electricity storage device of the present invention, the first connection terminal member preferably includes three or more rod-shaped portions.

  By comprising in this way, since each edge part and exterior body of a positive electrode and a negative electrode can be firmly clamped by the 1st and 2nd connection terminal member, with respect to the intense vibration etc. which are given from the outside It is possible to obtain an electrode lead structure that can withstand the same.

  In the electricity storage device of the present invention, the first connection terminal member has a through hole formed in the coupling portion, the second connection terminal member includes a rod-shaped portion formed integrally, It is preferable that the rod-shaped part of the connection terminal member is inserted into and engaged with the through hole of the first connection terminal member.

  By comprising in this way, engaging the some rod-shaped part of the 1st connecting terminal member with each of the some through-hole of the 2nd connecting terminal member, and the rod-like part of the 2nd connecting terminal member. It is easy to simultaneously engage with the through hole of the first connection terminal member. Thereby, it is not necessary to position each of the plurality of bar-shaped members every time a step of caulking the tip of the bar-shaped member called a rivet as in the prior art, and the manufacturing process can be simplified.

  In addition, since the first connecting terminal member has a plurality of rod-shaped portions and a connecting portion integrally formed, and the second connecting terminal member has a rod-shaped member integrally formed, the rod-shaped portion and The contact resistance can be reduced, and the deterioration of the characteristics of the electricity storage device can be prevented.

  A method of manufacturing an electricity storage device according to the present invention includes an exterior body that houses an electricity storage element, and an electricity storage device that includes a positive electrode connection terminal and a negative electrode connection terminal that are electrically connected to a positive electrode and a negative electrode of the electricity storage element, respectively. It is a manufacturing method. In the electricity storage device, each of the positive electrode connection terminal and the negative electrode connection terminal includes a first connection terminal member and a second connection terminal member. The first connection terminal member includes a plurality of rod-shaped portions and a connecting portion that is integrally formed at one end of the plurality of rod-shaped portions and connects the plurality of rod-shaped portions. The second connection terminal member is disposed so as to face the coupling portion and has a plurality of through holes.

  The method of manufacturing the electricity storage device configured as described above includes inserting the other end of the plurality of rod-shaped portions into each of the plurality of through-holes, and inserting the other end of the plurality of rod-shaped portions inserted and the plurality of through-holes. Are simultaneously engaged, and the exterior body and the end portions of the positive electrode and the negative electrode are sandwiched between the first connection terminal member and the second connection terminal member.

  In the method for manufacturing the electricity storage device of the present invention, by simultaneously engaging the other end of the plurality of rod-like portions connected by the connecting portion in the first connection terminal member with the through hole of the second connection terminal member. In addition, it is not necessary to position each of the plurality of bar-shaped members every time the step of caulking the tip of the bar-shaped member called a rivet as in the prior art, and the manufacturing process can be simplified.

  As described above, according to the present invention, it is possible to simplify the manufacturing process of the power storage device and to prevent the deterioration of the characteristics of the power storage device.

  Embodiments of an electricity storage device according to the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing a battery element of a lithium ion secondary battery which is one embodiment of the electricity storage device of the present invention, and FIG. 2 is a lithium ion secondary battery which is one embodiment of the electricity storage device of the present invention. 3 is a cross-sectional view taken along the line III-III of FIG. 2, FIG. 4 is a partial cross-sectional view taken along the line IV-IV of FIG. 2, and FIG. 3 is a partial cross-sectional view showing a cross section in the vicinity of a through hole formed in an end portion of an exterior body and a positive electrode current collector in FIG. 3, 4, and 5 show the cross section on the positive electrode side, but the negative electrode side is the same as the positive electrode side, and therefore, the following description will focus on the positive electrode side.

  With reference to FIGS. 1-5, the lithium ion secondary battery 1 which is one embodiment of the electrical storage device of this invention is demonstrated below.

  As shown in FIG. 1, in the battery element 10, a plurality of strip-shaped positive electrodes 11 and a plurality of strip-shaped negative electrodes 12 are alternately stacked via a plurality of strip-shaped separators 13. .

  Here, the positive electrode 11 is formed by laminating the positive electrode active material 112 on both surfaces of the positive electrode current collector 111. As an example, the positive electrode current collector 111 is made of aluminum, and the positive electrode active material 112 is made of lithium cobalt oxide composite oxide (LCO).

  On the other hand, the negative electrode 12 is formed by laminating a negative electrode active material 122 on both surfaces of a negative electrode current collector 121. As an example, the negative electrode current collector 121 is made of copper, and the negative electrode active material 122 is made of a carbon material.

  The positive electrode collecting end portion 113 in which the end portions of the plurality of positive electrode current collectors 111 constituting the plurality of positive electrodes 11 are aggregated is electrically connected to a positive electrode connection terminal 30 described later, and the plurality of negative electrodes 12 are connected. The negative electrode collecting end portion 123 in which the end portions of the plurality of negative electrode current collectors 121 constituting the above are integrated is electrically connected to a negative electrode connecting terminal 40 described later.

  As shown in FIG. 2, the lithium ion secondary battery 1 which is an example of an electrical storage device is equipped with the exterior body 20 which accommodates the battery element 10 shown by FIG. 1 as an example of an electrical storage element. The lithium ion secondary battery 1 includes a positive electrode connection terminal 30 electrically connected to the positive electrode collecting end portion 113 of the battery element 10 and a negative electrode connection electrically connected to the negative electrode collecting end portion 123 of the battery element 10. And a terminal 40.

  As shown in FIGS. 3 and 4, the outer package 20 includes an inner surface layer 21 disposed on the inner surface side facing the battery element 10, an intermediate layer 22, and an outer surface layer 23 disposed on the outer surface side facing the outside. It is formed with a laminate film having a three-layer structure composed of For example, the inner surface layer 21 is made of polypropylene, which is a heat-sealable thermoplastic resin, and has a thickness of 30 to 120 μm. As an example, the intermediate layer 22 is made of an aluminum foil or an aluminum alloy foil, and has a thickness of 30 to 50 μm. As an example, the outer surface layer 23 is made of nylon (registered trademark) and has a thickness of 20 to 40 μm.

  The exterior body 20 is formed by superposing two upper and lower laminate films cup-shaped in a shape having a recess. In the four surroundings of the outer package 20, the inner surface layers 21 facing each other are heat-sealed (heat-welded) as shown in FIGS. Is formed. The battery element 10 is accommodated in the exterior body 20 formed as described above, and the exterior body 20 is sealed by a heat seal portion 24. The laminate film is lightweight and has excellent flexibility, and has an excellent blocking function and sealing property against moisture from the outside.

  As shown in FIGS. 2 and 3, the end of the heat seal portion 24 at a position close to the tip end portion of the positive electrode connection terminal 30, that is, the protruding end portion of the flat plate portion 320 of the second connection terminal member 32 described later. In order to prevent a short circuit due to contact between the positive electrode connection terminal 30 and the metallic intermediate layer 22 of the exterior body 20, the insulating tape 25 (for example, Kapton (registered trademark)) made of polyimide resin having heat resistance and electrical insulation is used. Trademark)). As shown in FIG. 2, the width of the insulating tape 25 is larger than the width dimension of the positive electrode connection terminal 30, that is, the dimension in the width direction of the flat plate portion 320. As shown in FIG. It is formed so as to cover in the direction. The insulating tape 25 thus formed prevents contact between the positive electrode connection terminal 30 and the intermediate layer 22 of the outer package 20.

  As shown in FIGS. 2 to 4, the positive electrode connection terminal 30 includes a first connection terminal member 31 and a second connection terminal member 32. The first connection terminal member 31 and the second connection terminal member 32 are arranged so as to sandwich the exterior body 20 and the positive electrode collecting end portion 113.

  The first connection terminal member 31 is formed integrally with the plurality of rod-shaped portions 311 and 312 and one end portions 311a and 312a of the plurality of rod-shaped portions 311 and 312 and connects the plurality of rod-shaped portions 311 and 312. And a connecting plate portion 314 which is an example of a connecting portion.

  On the other hand, the second connection terminal member 32 is disposed so as to face the connection plate portion 314 of the first connection terminal member 31, and includes a flat plate portion 320 facing the connection plate portion 314. At the end portion of the flat plate portion 320 on the side in contact with the outer surface of the exterior body 20, a plurality of other end portions 311 b and 312 b of the plurality of rod-like portions 311 and 312 of the first connection terminal member 31 can be inserted. Through holes 321 and 322 are formed. In addition, a through hole 324 is formed at the end of the flat plate portion 320 on the side not in contact with the outer surface of the exterior body 20 in order to connect the positive electrode connection terminal 30 to an external connection terminal, an assembled battery, or the like.

  The positive electrode connection terminal 30 is inserted into the through holes 321 and 322 of the second connection terminal member 32 through the rod-shaped portions 311 and 312 of the first connection terminal member 31, and the other ends of the inserted rod-shaped portions 311 and 312. By engaging the portions 311b and 312b with the through holes 321 and 322 by caulking, the first connection terminal member 31 and the second connection terminal member 32 connect the exterior body 20 and the positive electrode collecting end 113, respectively. It is comprised so that it may pinch.

  Here, when the other end portions 311b and 312b of the rod-shaped portions 311 and 312 are engaged with the through-holes 321 and 322 and are caulked, the distal end portion that protrudes outside the flat plate portion 320 is in the axial direction. By being crushed, it is formed in a flange shape, and its outer surface has irregularities.

  As shown in FIGS. 3 and 4, the rod-shaped portions 311 and 312 are pressed and compressed in the axial direction when they are caulked to increase their diameters. However, the diameters of the rod-like portions 311 and 312 positioned in the through holes 321 and 322 of the second connection terminal member 32 remain the same as those before being caulked. This is also affected by the difference in the materials of the first connecting terminal member 31 and the second connecting terminal member 32 and the materials of the first connecting terminal member 31 and the second connecting terminal member 32. The Accordingly, step portions 311c and 312c having different diameters are formed in the vicinity of the through holes 321 and 322 in the rod-like portions 311 and 312. By engaging the flat plate portion 320 of the second connection terminal member 32 with the step portions 311c and 312c, more reliable contact between the rod-like portions 311 and 312 and the flat plate portion 320 is achieved, and the contact resistance is reduced. You can plan.

  In the first connection terminal member 31, in addition to the rod-shaped portions 311 and 312 and the connecting plate portion 314 being integrally formed in advance, the other end portions 311b and 312b to be caulked are also integrally formed. Therefore, for example, it is possible to more reliably prevent moisture from entering from the outside as compared to a fastening structure using bolts and nuts or an adhesive structure using resin or the like. Moreover, since the rod-shaped parts 311 and 312, the connecting plate part 314, and the other end parts 311 b and 312 b are integrally formed of the same material, thermal deformation due to a difference in thermal expansion coefficient can be prevented.

  Since the positive electrode connection terminal 30 is configured as described above, it has excellent sealing properties and conductivity.

  Further, the first connection terminal member 31 and the second connection terminal member 32 will be described more specifically.

  As shown in FIG. 3, the first connection terminal member 31 has a substantially U-shaped cross section, and is made of aluminum or an aluminum alloy that is the same material as the positive electrode current collector 111. The connecting plate portion 314 is formed in a relatively thick flat plate shape, and has a thickness of 0.3 to 3 mm, for example. The rod-like portions 311 and 312 have a circular cross section, and have a diameter of 2 to 8 mm, for example.

  On the other hand, the 2nd connection terminal member 32 is formed in flat form as a whole, consists of copper or a copper alloy, for example, is 0.3-3 mm in thickness. It is preferable that the second connection terminal member 32 be formed of copper or a copper alloy because contact resistance in use under a high voltage can be reduced.

  As shown in FIG. 2, the second connection terminal member 32 is parallel to the short direction of the battery element 10 and along the main plane of the exterior body 20 at one end in the longitudinal direction of the rectangular battery element 10. Are arranged. That is, the second connection terminal member 32 is not projected outside from the gap between the four heat seal portions 24 of the exterior body 20.

  As shown in FIG. 3, the dimension in the length direction of the first connection terminal member 31 is smaller than the dimension in the short direction of the battery element 10, that is, the dimension in the width direction. 1/2 to 1/5 of the dimension. As shown in FIG. 4, the dimension in the width direction of the first connection terminal member 31 is smaller than the dimension in the width direction of the second connection terminal member 32, for example, the width of the second connection terminal member 32. 1/2 to 1/5 of the dimension in the direction. As shown in FIG. 3, the thickness dimension of the connecting plate portion 314 of the first connection terminal member 31 is substantially the same as the thickness dimension of the flat plate portion 320 of the second connection terminal member 32. As shown in FIGS. 2 and 3, the dimension in the length direction of the second connection terminal member 32 is substantially the same as the dimension in the width direction of the battery element 10.

  In addition, the two rod-like portions 311 and 312 of the first connection terminal member 31 are arranged at the ends in the longitudinal direction of the battery element 10 and in the vicinity of the center in the lateral direction. By arranging the rod-shaped portions 311 and 312 near the center of the battery element 10 in the short direction, it becomes easy to caulk the rod-shaped portions 311 and 312 simultaneously with a jig (not shown). The interval between the two rod-like portions 311 and 312 is arbitrary, but is appropriately set so as to obtain sufficient mechanical strength that can withstand intense vibration.

  2 also has a structure similar to that of the positive electrode connection terminal 30 described above. As shown in FIG. 2, in the same manner as the positive electrode connection terminal 30, the negative electrode connection terminal 40 also has a first connection terminal member 42 on the side in contact with the outer surface of the exterior body 20. The other end portions 411b and 412b to which the connection terminal member 41 is caulked are disposed, and a through hole 424 is formed at the end portion of the second connection terminal member 42 on the side not contacting the outer surface of the exterior body 20. Yes. In the negative electrode connection terminal 40, both the first connection terminal member 41 and the second connection terminal member 42 are made of the same material as the negative electrode current collector 121 shown in FIG.

  As illustrated in FIG. 3, the annular space S surrounded by the rod-shaped portion 311, the flat plate portion 320, the exterior body 20, and the positive electrode collecting end portion 113 is filled with a seal member 50. An annular space surrounded by the rod-shaped portion 312, the flat plate portion 320, the exterior body 20, and the positive electrode collecting end portion 113 is also filled with the seal member 50. The seal member 50 is made of the same material as that of the inner surface layer 21 of the exterior body 20, for example, polypropylene, and has a ring shape. The sealing member 50 can improve the sealing performance and insulating properties around the rod-shaped portions 311 and 312.

  The lithium ion secondary battery 1 configured as described above can be summarized as follows. The exterior body 20 that houses the battery element 10 and the positive electrode connection electrically connected to each of the positive electrode 11 and the negative electrode 12 of the battery element 10. The terminal 30 and the negative electrode connection terminal 40 are provided. The positive connection terminal 30 and the negative connection terminal 40 are first connection terminal members disposed so as to sandwich the outer package 20 and the positive electrode collecting end 113 of the positive electrode 11 and the negative electrode collecting end 123 of the negative electrode 12, respectively. 31 and 41 and second connection terminal members 32 and 42. For example, on the positive electrode side, the first connection terminal member 31 is formed integrally with the plurality of rod-shaped portions 311, 312 and one end of the plurality of rod-shaped portions 311, 312, and the plurality of rod-shaped portions 311, And a connecting plate portion 314 for connecting 312. The second connection terminal member 32 is disposed so as to face the connecting plate portion 314 and has a plurality of through holes 321 and 322. The other end portions of the plurality of rod-shaped portions 311 and 312 are inserted into and engaged with the plurality of through holes 321 and 322, respectively.

  As described above, the first connection terminal member 31 includes the connecting plate portion 314 that is integrally formed at one end portion of the plurality of rod-shaped portions 311 and 312 and connects the plurality of rod-shaped portions 311 and 312. It is possible to easily engage the other end portions of the plurality of rod-shaped portions 311 and 312 connected by the plate portion 314 with the plurality of through holes 321 and 322 of the second connection terminal member 32 simultaneously. Thereby, it is not necessary to position each of the plurality of bar-shaped members every time the step of caulking the tip of the bar-shaped member called a rivet as in the prior art, and the manufacturing process can be simplified.

  Further, in the first connection terminal member 31, since the plurality of rod-shaped portions 311, 312 and the connecting plate portion 314 are integrally formed, the contact resistance between the rod-shaped portions 311, 312 and the connecting plate portion 314 is reduced. And deterioration of the characteristic of the lithium ion secondary battery 1 which is an example of an electrical storage device can be prevented.

  In the first embodiment, the battery element 10 is composed of a strip-shaped positive electrode, a strip-shaped separator, and a stack of strip-shaped negative electrodes, that is, a so-called single-wafer stacked body. It may be configured by folding and interposing a strip-shaped positive electrode and a strip-shaped negative electrode alternately. Moreover, as a structure of the battery element, a winding type structure in which a long positive electrode, a long separator, and a long negative electrode are wound may be employed. For example, the ends of the positive and negative electrode current collectors are pulled out in opposite directions along the winding axis, and the positive electrode connecting terminal and the negative electrode connecting terminal as in the above embodiment are electrically connected to the drawn portion. Thus, the configuration of the present invention can be applied.

  In the first embodiment, the example in which the battery element 10 of the lithium ion secondary battery 1 is applied as the power storage element has been described. However, the battery element may be applied to battery elements such as a lithium secondary battery and a polymer secondary battery. You may apply to the electrical storage element used for electrical storage devices, such as a double layer capacitor, and an electrical storage element is not specifically limited.

  The separator 13 shown in FIG. 1 is not particularly limited, and a conventionally known separator can be used. In the present invention, the separator is not limited by its name, and a solid electrolyte or gel electrolyte having a function (role) as a separator may be used instead of the separator. Further, a separator containing an inorganic material such as alumina or zirconia may be used.

As the positive electrode active material 112, lithium manganate composite oxide (LMO) or lithium nickelate composite oxide (LNO) may be used in addition to lithium cobaltate composite oxide (LCO). Further, as the positive electrode active material 112, a ternary material such as LNMCO or a binary material such as LMNO, LMCO, and LNCO may be used. Further, the positive electrode active material 112 may be a mixture of these main materials. The positive electrode active material 112 may be an olivine-based material such as LiFePO ₄ .

  As the carbon material of the negative electrode active material 122, graphite, hard carbon, or the like is used. The negative electrode active material 122 may be a mixture of these main materials. The negative electrode active material 122 may be a ceramic or alloy material such as lithium titanate.

  In Embodiment 1 described above, a laminate film having a three-layer structure is used as the exterior body 20, but between the inner surface layer 21 and the intermediate layer 22 of the exterior body 20 and between the intermediate layer 22 and the outer surface layer 23. An adhesive layer may be interposed. Further, an inner surface layer 21 composed of a plurality of layers may be arranged inside the intermediate layer 22. An outer surface layer 23 composed of a plurality of layers may be disposed outside the intermediate layer 22. The intermediate layer 22 may have a multilayer structure. The material of the intermediate layer 22 may be any metal that has a barrier property against moisture and the like and is excellent in flexibility and strength, such as stainless steel, nickel or nickel alloy, copper or copper alloy, iron or iron alloy. Etc. The intermediate layer 22 may be formed in a foil shape or a thin plate shape in advance, or may be formed by a thin film or a plating layer.

  The inner surface layer 21 may be a thermoplastic resin excellent in electrolytic solution resistance and heat sealability, and may be a resin such as polyethylene, polystyrene, polyamide, or ionomer. The outer surface layer 23 may be an insulating resin excellent in electrical insulation, and may be a resin such as polyester (such as PET) or other polyamide.

  In the first embodiment, the two laminate films are overlapped, the heat seal portions 24 on the four sides are heat-sealed, and the two laminate films are sealed so that the battery element 10 is accommodated in the exterior body 20. However, as a method for sealing the laminate film, after the one laminate film is folded in two, the remaining three heat seal portions 24 around the periphery may be heat-welded. Moreover, after forming the laminated film of 1 sheet in a cylinder shape, you may heat-seal the heat seal part 24 of both sides. In addition, when forming in a cylinder shape, the position of the strip | belt-shaped heat seal part heat-welded previously can be set arbitrarily.

  The means for engaging the other end portions 311b and 312b of the rod-like portions 311 and 312 of the first connection terminal member 31 with the through holes 321 and 322 of the second connection terminal member 32 is not limited to the caulking, but screws Alternatively, means such as bolt and nut fastening, ultrasonic welding, laser welding, etc. may be employed.

  In the first embodiment, two rod-like portions 311 and 312 are provided on the positive electrode connection terminal 30 side, and two rod-like portions (411 and 412) (not shown) are provided on the negative electrode connection terminal 40 side. Is not particularly limited. However, when the lithium ion secondary battery 1 is used, for example, in an application involving intense vibrations, the number of rod-like portions is to prevent the rotation of the second connection terminal members 32 and 42 due to vibrations. It is preferable that there are at least two or more.

  In the first embodiment, the cross-sectional shape of the rod-like portions 311 and 312 is circular, but may be an ellipse or a polygon, for example. If the cross-sectional shape of the rod-shaped parts 311 and 312 is an ellipse or a polygon, it is effective to prevent the rotation of the second connection terminal members 32 and 42 due to vibration. The diameters of the rod-like portions 311 and 312 may not be the same.

  In order to flatten the unevenness on the outer surface of the other end portions 311b and 312b of the first connection terminal member 31, press working may be performed after caulking. Further, laser welding, resin coating, soldering, or the like may be applied to the outer surfaces of the other end portions 311b and 312b of the first connection terminal member 31.

  In order to prevent damage to the inner surface layer 21 of the exterior body 20, it is preferable to chamfer or curve the surface of the connection plate portion 314 of the first connection terminal member 31.

  As the shape of the second connection terminal member 32, a free shape can be adopted. In the first embodiment, the shape of the second connection terminal member 32 is a flat plate extending in the linear direction, but is not limited to a flat plate and is not in contact with the outer surface of the exterior body 20. 2, that is, the end on the side where the through-hole 324 shown in FIGS. 2 and 3 is formed is bent in a key shape, curved in an arc shape, or bifurcated. Good. Further, the dimension in the length direction, the dimension in the width direction, and the dimension in the thickness direction of the second connection terminal member 32 do not have to be uniform as shown in FIG. 3 and FIG. You may form a thin part and a thick part in one place.

  The lead-out direction of the second connection terminal member 32 of the positive electrode connection terminal 30 and the second connection terminal member 42 of the negative electrode connection terminal 40 is parallel to the short direction of the exterior body 20 and the same as in the first embodiment. For example, the second connection terminal member 32 and the second connection terminal member 42 may be pulled out in the longitudinal direction of the exterior body 20 (in the left-right direction in FIG. 2) in opposite directions. . In addition, the second connection terminal member 32 of the positive electrode connection terminal 30 and the second connection terminal member 42 of the negative electrode connection terminal 40 are not limited to those that pull out in the same direction as in the first embodiment. The connection terminal member 32 and the second connection terminal member 42 may be pulled out in opposite directions or in an asymmetric direction.

  In the first embodiment, the first connection terminal member 31 and the second connection terminal member 32 are formed of different materials, but may be formed of the same material. When the material of the second connection terminal member 32 is made of aluminum or an aluminum alloy like the material of the first connection terminal member 31, it is advantageous in terms of weight reduction.

  The material of the first connection terminal member 41 and the second connection terminal member 42 of the negative electrode connection terminal 40 is the same material as that of the negative electrode current collector 121, but may be a different material. Nickel plating or tin plating may be applied to the surface of the second connection terminal member 42.

  The longitudinal dimension of the first connection terminal member 31 and the second connection terminal member 32, the dimension in the width direction, the dimension in the thickness direction, and the magnitude relationship between these dimensions are not limited to the first embodiment, It can be set arbitrarily. For example, when the materials of the first connection terminal member 31 and the second connection terminal member 32 are different, the longitudinal dimension, the width dimension, or the thickness direction dimension is the same as that of the first connection terminal member 31. In some cases, it may be better to make the second connection terminal member 32 different, and these dimensions are appropriately set according to the allowable current of the material of the first connection terminal member 31 and the second connection terminal member 32. The

  The seal member 50 may be a thermoplastic resin excellent in electrolytic solution resistance and sealability, and may be a resin such as polyethylene, polystyrene, polyamide, nylon, or ionomer.

  Further, in the first embodiment, the seal member 50 previously formed in a ring shape is used. However, a liquid seal member may be injected around the rod-shaped portions 311 and 312.

  Further, the sealing member 50 may be an insulating resin as described above, but may be an elastic material such as natural rubber or synthetic rubber. Thereby, stress relaxation around the rod-like portions 311 and 312 can be achieved.

  In the first embodiment, the bush member is implanted around the rod-shaped portions 311 and 312 and the seal member 50 is formed so as to bite around the rod-shaped portions 311 and 312 when caulked. Good.

  Next, the manufacturing method of the lithium ion secondary battery 1 which is an example of the electrical storage device of this invention is demonstrated. Although the manufacturing method of a lithium ion secondary battery is not limited, For example, the lithium ion secondary battery 1 shown by FIGS. 1-4 can be manufactured in the following procedures. In addition, since the positive electrode side and the negative electrode side are the same in the manufacturing method, the description will focus on the positive electrode side.

  (1) First, as shown in FIG. 5, through holes 101, 102, 201, 202 corresponding to the predetermined positions of the positive electrode collector 113, the outer package 20, and the second connection terminal member 32, respectively. , 321 and 322 are formed.

  As shown in FIG. 3, a through hole 324 that can be connected to an external connection terminal or an assembled battery is formed at the tip of the second connection terminal member 32.

  Here, the through holes 101 and 102 of the positive electrode collecting end portion 113 and the through holes 321 and 322 of the second connection terminal member 32 have substantially the same diameter as the diameters of the rod-like portions 311 and 312 of the first connection terminal member 31. It forms so that it may have. On the other hand, the through holes 201 and 202 of the exterior body 20 are formed in advance larger than the diameters of the rod-like portions 311 and 312. Thereby, when the rod-shaped portions 311 and 312 are inserted, a space S is formed between the rod-shaped portions 311 and 312 and the exterior body 20 (particularly, the intermediate layer 22).

  (2) Next, the positive electrode collecting end portion 113 and the first connection terminal member 31 of the positive electrode connection terminal 30 are connected. Specifically, the rod-like portions 311 and 312 of the first connection terminal member 31 are inserted into the through holes 101 and 102 of the positive electrode collecting end portion 113, and the positive electrode collecting end portion 113 and the connecting plate portion 314 are used by a jig (not shown). And ultrasonic welding.

  (3) Then, the battery element 10 connected to the first connection terminal member 31 via the positive electrode collecting end portion 113 is accommodated in the upper and lower two exterior bodies 20 cup-shaped in a shape having a recess. .

  (4) Thereafter, the through holes 201, 202, 321, 322 of the exterior body 20 and the second connection terminal member 32 are aligned and inserted into the rod-like portions 311, 312 of the first connection terminal member 31. At this time, the seal member 50 is interposed between the through holes 201 and 202 of the exterior body 20 and the rod-like portions 311 and 312.

  (5) Further, the tip portions of the rod-shaped portions 311 and 312 are pressed against the protruding tip portions of the rod-shaped portions 311 and 312 with a jig (not shown) by a method such as hammering, hydraulic pressure, and pneumatic pressure and simultaneously crimped. Is crushed to form the other end portions 311b and 312b. Thereby, the sealing member 50 is filled in an airtight manner. Further, the caulking process electrically connects the first connection terminal member 31 and the second connection terminal member 32.

  (6) Next, the inner surface layers 21 are thermally welded at three sides around the exterior body 20 to form the heat seal portion 24.

  (7) And after injecting electrolyte solution from one opening part of the exterior body 20 which is not heat-sealed yet, the inner surface layers 21 are heat-welded in the one opening part, and a temporary heat seal part is formed. To do.

  (8) Finally, initial charging is performed, a part of the heat seal portion 24 is cut, the gas is removed from the cut portion, and then a part of the cut heat seal portion 24 is thermally welded again and vacuum suction is performed. And seal the whole.

  (9) The lithium ion secondary battery 1 which is an example of the electrical storage device of this invention is manufactured as mentioned above.

  Therefore, in the method for manufacturing the lithium ion secondary battery 1 which is an example of the electricity storage device of the present invention, for example, on the positive electrode side, the other end portions of the plurality of rod-like portions 311 and 312 in the first connection terminal member 31 are The second connection terminal member 32 is inserted into each of the plurality of through holes 321 and 322, and the other end of the inserted plurality of rod-like parts 311 and 312 and the plurality of through holes 321 and 322 are simultaneously engaged. The exterior body 20 and the positive electrode collecting end portion 113 are sandwiched between the first connection terminal member 31 and the second connection terminal member 32.

  Accordingly, the other end portions of the plurality of rod-like portions 311 and 312 connected by the connecting plate portion 314 in the first connection terminal member 31 are simultaneously engaged with the through holes 321 and 322 of the second connection terminal member 32. Thus, it is not necessary to position each of the plurality of bar-shaped members every time a step of caulking the tip of the bar-shaped member called a rivet as in the prior art, and the manufacturing process can be simplified.

  Specifically, the lithium ion secondary battery 1 of the present invention can be manufactured by manufacturing the lithium ion secondary battery 1 which is an example of the electricity storage device of the present invention using each component of the following specifications. Verified.

(A) Battery element 10 (dimension of laminate): 300 mm (dimension in the longitudinal direction) × 120 mm (dimension in the width direction) × 5 mm (T dimension)
(B) Positive electrode active material 112: Lithium cobaltate (c) Negative electrode active material 122: Carbon material (d) Separator 13: Polyolefin separator (e) First connection terminal members 31 and 41
(E-1) Connecting plate part 314 (414): 30 mm (dimension in the longitudinal direction) x 15 mm (dimension in the width direction) x 1.5 mm (dimension in the thickness direction), (e-2) rod-like part 311, 312 (411, 412): diameter 6 mmφ × height 15 mm (size before caulking), made of aluminum or copper, diameter 8 mm at the other end, distance between rod-shaped parts 311, 312 25 mm
(F) Second connection terminal members 32 and 42
(F-1) Flat plate portion 320 (420): 100 mm (dimension in the longitudinal direction) × 15 mm (dimension in the width direction) × 1.5 mm (dimension in the thickness direction), made of aluminum or copper (f-2) through-hole 321 322 (421, 422): Diameter 6mmφ
(G) Exterior body 20: 320 mm (longitudinal dimension) × 135 mm (width dimension) × 7 mm (thickness dimension)
(G-1) Aluminum laminate film (inner layer 21: polypropylene having a thickness of 80 μm, intermediate layer 22: aluminum foil having a thickness of 40 μm, outer layer 23: nylon having a thickness of 25 μm)
(G-2) Diameter of through-holes 201 and 202: 8 mm
(H) Electrolytic solution: 1 mol / L of LiPF ₆ dissolved as a salt in ethylene carbonate (EC) and diethyl carbonate (DEC) (i) Production method: Follow the production method described above.

  Under the above conditions, a lithium ion secondary battery having a battery capacity of 10 Ah and a voltage of 4.2 V was fabricated as the lithium ion secondary battery 1 of the first embodiment.

(Embodiment 2)
FIG. 6 is a cross-sectional view of the lithium ion secondary battery according to another embodiment of the present invention, viewed from the direction along the line III-III in FIG. It is a fragmentary sectional view which shows the cross section of the made through-hole vicinity.

  In the first embodiment shown in FIG. 3, the first connecting terminal member 31 is provided with two rod-like portions 311 and 312, whereas in the second embodiment shown in FIG. 6, the first connecting terminal member 31 has the first connecting terminal member 31. Three rod-like portions 311, 312, and 313 are provided. Other configurations of the second embodiment are the same as those of the first embodiment.

  As described above, the first connecting terminal member 31 is configured to include three or more rod-shaped portions, whereby the positive electrode collecting end portion 113 and the negative electrode collecting end portion 123 and the exterior body 20 are respectively connected to the first and second. Since the connection terminal members 31 and 32 can be firmly clamped, it is possible to obtain an electrode lead structure that can withstand severe vibrations given from the outside.

(Embodiment 3)
FIG. 7 is a cross-sectional view of the lithium ion secondary battery according to another embodiment of the present invention as seen from the direction along the line III-III in FIG. 2, and is formed at the ends of the outer package and the positive electrode current collector. It is a fragmentary sectional view which shows the cross section of the made through-hole vicinity.

  In the first embodiment shown in FIG. 3, the first connecting terminal member 31 is provided with two rod-like portions 311 and 312, whereas in the third embodiment shown in FIG. Two rod-like portions 311 and 313 are provided, and one rod-like portion 325 is provided on the second connection terminal member 32. Other configurations of the third embodiment are the same as those of the first embodiment.

  The first embodiment is shown as an example in which at least one rod-like portion and at least one through hole are provided in each of the first connection terminal member 31 and the second connection terminal member 32. Each of the one connection terminal member 31 and the second connection terminal member 32 may be provided with one rod-like portion and one through hole.

  In the third embodiment shown in FIG. 7, the first connection terminal member 31 has a through-hole 315 formed in the connecting plate portion 314, and the second connection terminal member 32 is an integrally formed rod-shaped portion. 325, the rod-shaped portion 325 of the second connection terminal member 32 is inserted into and engaged with the through hole 315 of the first connection terminal member 31. With this configuration, the plurality of rod-like portions 311 and 313 of the first connection terminal member 31 are engaged with the plurality of through holes 321 and 322 of the second connection terminal member 32 respectively. It is easily possible to simultaneously engage the rod-like portion 325 of the connection terminal member 32 with the through hole 315 of the first connection terminal member 31. Thereby, it is not necessary to position each of the plurality of bar-shaped members every time the step of caulking the tip of the bar-shaped member called a rivet as in the prior art, and the manufacturing process can be simplified.

  In the first connection terminal member 31, a plurality of rod-shaped portions 311, 313 and a connecting plate portion 314 are integrally formed, and in the second connection terminal member 32, a rod-shaped portion 325 is integrally formed. Therefore, the contact resistance with the rod-shaped parts 311, 313, and 325 can be reduced, and the deterioration of the characteristics of the lithium ion secondary battery 1 can be prevented.

  Further, each of the positive electrode collecting end portion 113 and the negative electrode collecting end portion 123 and the exterior body 20 can be more firmly held by the first and second connection terminal members 31 and 32, and intense vibrations given from the outside, etc. It is possible to obtain an electrode lead structure that can withstand the above. In the third embodiment, as compared with the second embodiment, the number of through holes formed in the second connection terminal member 32 on the outer surface side is smaller, so that the sealing performance can be made higher than that in the second embodiment. .

  It should be considered that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above embodiments but by the scope of the claims, and is intended to include all modifications and variations within the meaning and scope equivalent to the scope of the claims.

  The electricity storage device of the present invention is suitable for devices that are used in applications involving severe vibration, such as automobiles and motorcycles. That is, as disclosed in the conventional example of Patent Document 1, a structure in which the connection terminal protrudes from the heat-sealed heat-sealed portion of the exterior body, in other words, the exterior body is chemically bonded to each other, thereby connecting In the structure in which the terminal is sandwiched, the battery element and the connection terminal vibrate vigorously due to vigorous vibration from the outside, and the sealing performance of the heat seal portion may be deteriorated. On the other hand, in the electricity storage device of the present invention, the first connection terminal member and the second connection terminal member of the connection terminal are mechanically and electrically joined, and the first connection terminal member and the second connection terminal Since the exterior body is sandwiched between the connection terminal members, the exterior body is firmly held against strong external vibrations while maintaining a high sealing performance and high insulation with a simple configuration. Sex can also be maintained. Therefore, the electricity storage device of the present invention is suitable for being used at a high voltage of 100 V or higher, for example, 500 to 1000 V.

It is sectional drawing which shows the battery element of the lithium ion secondary battery which is one embodiment of the electrical storage device of this invention. It is a top view which shows the lithium ion secondary battery which is one embodiment of the electrical storage device of this invention. It is sectional drawing seen from the direction along the III-III line of FIG. It is the fragmentary sectional view seen from the direction along the IV-IV line of FIG. It is a fragmentary sectional view which shows the cross section of the through-hole vicinity formed in the edge part of an exterior body and a positive electrode collector in FIG. In the lithium ion secondary battery according to another embodiment of the present invention, a through hole formed in the end portion of the outer package and the positive electrode current collector in a cross section seen from the direction along line III-III in FIG. It is a fragmentary sectional view which shows the cross section of the vicinity. In the lithium ion secondary battery according to yet another embodiment of the present invention, a through hole formed in the end portion of the outer package and the positive electrode current collector in a cross section viewed from the direction along line III-III in FIG. It is a fragmentary sectional view which shows the cross section of the vicinity. It is a perspective view which shows the conventional sheet-like lithium ion secondary battery. It is a fragmentary sectional view in the IX-IX line of FIG.

Explanation of symbols

1: lithium ion secondary battery, 10: battery element, 11: positive electrode, 12: negative electrode, 20: exterior body, 30: positive electrode connection terminal, 40: negative electrode connection terminal, 31, 41: first connection terminal member, 32 , 42: second connection terminal member, 113: positive electrode collecting end, 123: negative electrode collecting end, 311, 312, 313, 325: rod-shaped portion, 314: connecting plate portion, 320: flat plate portion, 315, 321, 322: A through hole.

Claims (4)

An electricity storage device comprising: an exterior body that houses a power storage element; and a positive electrode connection terminal and a negative electrode connection terminal that are electrically connected to the positive electrode and the negative electrode of the power storage element, respectively.
The positive electrode connection terminal and the negative electrode connection terminal respectively include a first connection terminal member and a second connection terminal member arranged so as to sandwich the exterior body and the respective ends of the positive electrode and the negative electrode. Including
The first connection terminal member includes a plurality of rod-shaped portions, and a connecting portion that is integrally formed with one end portion of the plurality of rod-shaped portions and connects the plurality of rod-shaped portions;
The second connection terminal member is disposed so as to face the coupling portion, and has a plurality of through holes,
The electric storage device, wherein the other end portions of the plurality of rod-shaped portions are inserted and engaged with the respective through holes.   The power storage device according to claim 1, wherein the first connection terminal member includes three or more of the rod-shaped portions. The first connection terminal member has a through hole formed in the coupling portion,
The second connection terminal member includes an integrally formed rod-shaped portion,
The power storage device according to claim 1 or 2, wherein a rod-like portion of the second connection terminal member is inserted into and engaged with a through hole of the first connection terminal member. A method of manufacturing an electricity storage device comprising: an exterior body that houses an electricity storage element; and a positive electrode connection terminal and a negative electrode connection terminal electrically connected to each of a positive electrode and a negative electrode of the electricity storage element,
The positive connection terminal and the negative connection terminal each include a first connection terminal member and a second connection terminal member,
The first connection terminal member includes a plurality of rod-shaped portions, and a connecting portion that is integrally formed with one end portion of the plurality of rod-shaped portions and connects the plurality of rod-shaped portions;
The second connection terminal member is disposed so as to face the coupling portion, and has a plurality of through holes,
The other end portions of the plurality of rod-shaped portions are inserted into the plurality of through holes, and the other end portions of the inserted plurality of rod-shaped portions and the plurality of through holes are simultaneously engaged, A method for manufacturing an electricity storage device, wherein the exterior body and each end of the positive electrode and the negative electrode are sandwiched between a connection terminal member and a second connection terminal member.

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