JP2019067577A - Power storage device and manufacturing method of power storage device - Google Patents

Power storage device and manufacturing method of power storage device Download PDF

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JP2019067577A
JP2019067577A JP2017190333A JP2017190333A JP2019067577A JP 2019067577 A JP2019067577 A JP 2019067577A JP 2017190333 A JP2017190333 A JP 2017190333A JP 2017190333 A JP2017190333 A JP 2017190333A JP 2019067577 A JP2019067577 A JP 2019067577A
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electrode
positive electrode
tab group
electrode tab
thickness direction
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幸男 播磨
Yukio Harima
幸男 播磨
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Panasonic Corp
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50Manufacturing or production processes characterised by the final manufactured product

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Abstract

To provide a power storage device capable of reducing the dead space in a case housing an electrode body, and the like.SOLUTION: A power storage device has an electrode body 12, an electrode tab group superposing multiple electrode tabs projecting from the marginal part of the electrode body 12, and a collector member for connection with the electrode tab group. The electrode tab group has a first positive electrode tab group 66 and a second positive electrode tab group 68 divided in the thickness direction of the electrode body 12, the first positive electrode tab group 66 and the second positive electrode tab group 68 have first and second bent parts (70a, 70b) bent inward of the electrode body 12 in the thickness direction, and first and second extensions (72a, 72b) extending from the first and second bent parts (70a, 70b) in the thickness direction of the electrode body 12, and the collector member has first and second positive electrode collector members (74, 76) connected with one end or the other end of the electrode tab in the first and second extensions (72a, 72b).SELECTED DRAWING: Figure 3

Description

本開示は、蓄電装置及び蓄電装置の製造方法に関する。   The present disclosure relates to a power storage device and a method of manufacturing the power storage device.

EV(Electric Vehicle)やPHV(Plug in Hybrid Vehicle)等の車両には、モータへの供給電力を蓄える蓄電装置として、リチウムイオン二次電池等の二次電池が搭載されている。   2. Description of the Related Art In vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles), secondary batteries such as lithium ion secondary batteries are mounted as power storage devices for storing power supplied to a motor.

例えば、蓄電装置は、電極体と、電極体の縁部から突出した複数の電極タブが重ねられた電極タブ群と、電極体との間で電気を授受する電極端子と、電極タブの重なり方向における電極タブ群に接続され、電極タブ群から前記電極端子へと導電させる集電部材と、を有する。   For example, in the power storage device, an electrode body, an electrode tab group in which a plurality of electrode tabs protruding from an edge of the electrode body are overlapped, an electrode terminal for transferring electricity between the electrode body, and an overlapping direction of the electrode tab And a current collecting member connected to the electrode tab group in and conducting from the electrode tab group to the electrode terminal.

特開2003−249423号公報JP 2003-249423 A

ところで、電極体の縁部から突出した複数の電極タブが重ねられた電極タブ群は、電極体と当該電極体を収容するケース内面との間の空間に配置される。この電極タブ群が配置される空間はデッドスペースとなるため、電極タブ群の配置状態によっては、デッドスペースが大きくなり、電池サイズやエネルギー密度等に影響を与える。   By the way, an electrode tab group in which a plurality of electrode tabs projecting from an edge of the electrode body is overlapped is disposed in a space between the electrode body and an inner surface of a case that accommodates the electrode body. Since the space in which the electrode tab group is disposed is a dead space, the dead space becomes large depending on the arrangement state of the electrode tab group, which affects the battery size, the energy density, and the like.

そこで、本開示の目的は、電極体等を収容するケース内のデッドスペースを削減することが可能な蓄電装置および当該蓄電装置の製造方法を提供することである。   Therefore, an object of the present disclosure is to provide a power storage device capable of reducing a dead space in a case for housing an electrode body or the like, and a method of manufacturing the power storage device.

本開示の一態様である蓄電装置は、電極体と、前記電極体の縁部から突出した複数の電極タブを重ねた電極タブ群と、前記電極体との間で電気を授受する電極端子と、前記電極タブ群に接続され、前記電極タブ群から前記電極端子へと導電させる集電部材と、を有する蓄電装置であって、前記電極タブ群は、前記電極体の厚み方向において分割された第1電極タブ群と第2電極タブ群とを有し、前記第1電極タブ群は、前記電極体の厚み方向内側に折り曲げられた第1折曲部と、前記第1折曲部から前記電極体の厚み方向に延在する第1延在部と、を有し、前記第2電極タブ群は、前記電極体の厚み方向内側に折り曲げられた第2折曲部と、前記第2折曲部から前記電極体の厚み方向に延在する第2延在部と、を有し、前記集電部材は、前記第1延在部における前記電極タブの重なり方向の一端又は他端に接続された第1集電部材と、前記第2延在部における前記電極タブの重なり方向の一端又は他端に接続された第2集電部材と、を有する。   An electricity storage device according to an aspect of the present disclosure includes an electrode body, an electrode tab group in which a plurality of electrode tabs protruding from an edge portion of the electrode body are overlapped, and an electrode terminal for transferring electricity between the electrode body and the electrode tab group. And a current collecting member connected to the electrode tab group and conducting electricity from the electrode tab group to the electrode terminal, wherein the electrode tab group is divided in the thickness direction of the electrode body. The first electrode tab group has a first electrode tab group and a second electrode tab group, and the first electrode tab group includes a first bent portion bent inward in a thickness direction of the electrode body and the first bent portion. A second extending portion extending in a thickness direction of the electrode body, and the second electrode tab group includes a second bending portion bent inward in a thickness direction of the electrode body, and the second bending portion And a second extending portion extending from the curved portion in the thickness direction of the electrode body, wherein the current collecting member A first current collecting member connected to one end or the other end of the electrode tab in the overlapping direction in the first extending portion, and a first current collecting member connected to the one end or the other end in the overlapping direction of the electrode tab in the second extending portion And 2 current collecting members.

本開示の一態様である蓄電装置の製造方法は、電極体の縁部から突出した複数の電極タブを、前記電極体の厚み方向に分割するようにそれぞれ重ねて第1電極タブ群及び第2電極タブ群を形成する第1工程と、前記電極タブの重なり方向における前記第1電極タブ群の一端又は他端に第1集電部材を接続し、前記電極タブの重なり方向における前記第2電極タブ群の一端又は他端に第2集電部材を接続する第2工程と、前記第1電極タブ群を前記電極体の厚み方向内側に折り曲げて、第1折曲部及び前記第1折曲部から前記電極体の厚み方向に延在する第1延在部を形成すると共に、前記第2電極タブ群を前記電極体の厚み方向内側に折り曲げて、第2折曲部及び前記第2折曲部から前記電極体の厚み方向に延在する第2延在部を形成する第3工程と、を有し、前記3工程では、前記第1集電部材が前記第1延在部に位置するように前記第1電極タブ群を折り曲げ、前記第2集電部材が前記第2延在部に位置するように前記第2電極タブ群を折り曲げる。   According to a method of manufacturing a power storage device, which is an aspect of the present disclosure, a plurality of electrode tabs protruding from an edge portion of an electrode body are respectively overlapped in a thickness direction of the electrode body so as to be divided. In the first step of forming an electrode tab group, a first current collecting member is connected to one end or the other end of the first electrode tab group in the overlapping direction of the electrode tabs, and the second electrode in the overlapping direction of the electrode tabs A second step of connecting a second current collecting member to one end or the other end of the tab group, and bending the first electrode tab group inward in a thickness direction of the electrode body to form a first bending portion and the first bending Forming a first extension portion extending in a thickness direction of the electrode body from a portion, and bending the second electrode tab group inward in a thickness direction of the electrode body to form a second bent portion and the second bent portion Forming a second extension portion extending from the curved portion in the thickness direction of the electrode body And in the three steps, the first electrode tab group is bent so that the first current collecting member is positioned at the first extension portion, and the second current collecting member is extended by the second extension. The second electrode tab group is bent so as to be located at the bottom.

本開示の一態様によれば、電極体等を収容するケース内のデッドスペースを削減することが可能となる。   According to one aspect of the present disclosure, it is possible to reduce the dead space in the case that accommodates the electrode body and the like.

本実施形態の一例である二次電池の構成要素を示す模式図である。It is a schematic diagram which shows the component of the secondary battery which is an example of this embodiment. 電極体の構成要素を示す分解模式斜視図である。It is a disassembled schematic perspective view which shows the component of an electrode body. 正極集電部材を正極タブ群に接続した電極体の模式図である。It is a schematic diagram of the electrode body which connected the positive electrode current collection member to the positive electrode tab group. 図3に示す電極体の製造方法の一例を説明するための図である。It is a figure for demonstrating an example of the manufacturing method of the electrode body shown in FIG. 正極集電部材を正極タブ群に接続した電極体の第1変形例を示す模式図である。It is a schematic diagram which shows the 1st modification of the electrode body which connected the positive electrode current collection member to the positive electrode tab group. 図5に示す電極体の製造方法の一例を説明するための図である。It is a figure for demonstrating an example of the manufacturing method of the electrode body shown in FIG. 正極集電部材を正極タブ群に接続した電極体の第2変形例を示す模式図である。It is a schematic diagram which shows the 2nd modification of the electrode body which connected the positive electrode current collection member to the positive electrode tab group. 図7に示す電極体の製造方法の一例を説明するための図である。It is a figure for demonstrating an example of the manufacturing method of the electrode body shown in FIG. 正極集電部材を正極タブ群に接続した電極体の第3変形例を示す模式図である。It is a schematic diagram which shows the 3rd modification of the electrode body which connected the positive electrode current collection member to the positive electrode tab group. 図9に示す電極体の製造方法の一例を説明するための図である。It is a figure for demonstrating an example of the manufacturing method of the electrode body shown in FIG.

以下、実施形態の一例について詳細に説明する。実施形態の説明で参照する図面は、模式的に記載されたものであり、図面に描画された構成要素の寸法比率などは、現物と異なる場合がある。   Hereinafter, an example of the embodiment will be described in detail. The drawings referred to in the description of the embodiments are schematically described, and the dimensional ratio of the component drawn in the drawings may be different from the actual one.

図1は、本実施形態の一例である二次電池の構成要素を示す模式図である。図1に示すように、蓄電装置としての二次電池10は、電極体12、電極体12の縁部から突出した正極タブ群14及び負極タブ群16、正極集電部材18及び負極集電部材20、正極端子22及び負極端子24、ケース26を備える。本実施形態の二次電池10はリチウムイオン電池であり、外郭が角型をなす角型電池である。   FIG. 1 is a schematic view showing components of a secondary battery which is an example of the present embodiment. As shown in FIG. 1, the secondary battery 10 as a power storage device includes an electrode body 12, a positive electrode tab group 14 and a negative electrode tab group 16 protruding from the edge of the electrode body 12, a positive electrode current collector 18 and a negative electrode current collector 20, the positive electrode terminal 22, the negative electrode terminal 24, and the case 26 are provided. The secondary battery 10 of the present embodiment is a lithium ion battery, and is a rectangular battery whose outer shell has a rectangular shape.

ケース26は、四角箱状の本体部28と矩形平板状の封口体30とから構成される。図1に示すように、封口体30の内面及び外面には絶縁部材32a,32bが設けられ、外面側に配置された絶縁部材32b上には金属基板34が設けられることが望ましい。   The case 26 is composed of a rectangular box-shaped main body 28 and a rectangular flat sealing member 30. As shown in FIG. 1, it is desirable that insulating members 32a and 32b be provided on the inner surface and the outer surface of the sealing body 30, and a metal substrate 34 be provided on the insulating member 32b disposed on the outer surface side.

正極端子22は、正極外部端子36と正極内部端子38とを有する。また、負極端子24は、負極外部端子40と負極内部端子42とを有する。   The positive electrode terminal 22 has a positive electrode external terminal 36 and a positive electrode internal terminal 38. Further, the negative electrode terminal 24 has a negative electrode external terminal 40 and a negative electrode internal terminal 42.

正極外部端子36及び負極外部端子40は、金属板44と、金属板44上に設けられたリベット部46とを有する。また、正極外部端子36及び負極外部端子40の金属板44は、例えば、封口体30の内面に設けられた絶縁部材32aに固定されている。正極外部端子36及び負極外部端子40の金属板44上に形成されたリベット部46はそれぞれ、絶縁部材32a、封口体30、絶縁部材32b、金属基板34を介して、ケース26の外部に露出している。   The positive electrode external terminal 36 and the negative electrode external terminal 40 have a metal plate 44 and a rivet portion 46 provided on the metal plate 44. The metal plate 44 of the positive electrode external terminal 36 and the negative electrode external terminal 40 is fixed to, for example, an insulating member 32 a provided on the inner surface of the sealing body 30. The rivet portions 46 formed on the metal plate 44 of the positive electrode external terminal 36 and the negative electrode external terminal 40 are exposed to the outside of the case 26 through the insulating member 32a, the sealing body 30, the insulating member 32b, and the metal substrate 34, respectively. ing.

正極内部端子38は、クランク形状であり、屈曲部分に対して長手方向の一方側の部位が正極集電部材18に接続され、屈曲部分に対して長手方向の他方側の部位が正極外部端子36の金属板44に接続されている。負極内部端子42も同様に、クランク形状であり、屈曲部分に対して長手方向の一方側の部位が負極集電部材20に接続され、屈曲部分に対して長手方向の他方側の部位が負極外部端子40の金属板44に接続されている。   The positive electrode internal terminal 38 has a crank shape, and a portion on one side in the longitudinal direction with respect to the bent portion is connected to the positive electrode current collector member 18 and a portion on the other side in the longitudinal direction with respect to the bent portion is the positive electrode external terminal 36 Is connected to the metal plate 44 of FIG. Similarly, the negative electrode internal terminal 42 is also crank-shaped, and a portion on one side in the longitudinal direction with respect to the bent portion is connected to the negative electrode current collector member 20, and a portion on the other side in the longitudinal direction with respect to the bent portion is the outside of the negative electrode It is connected to the metal plate 44 of the terminal 40.

図2は、電極体12の構成要素を示す分解模式斜視図である。図2に示すように、電極体12は、シート状の正極48と、シート状の負極50と、セパレータ52とを備える。正極48は、正極金属箔54(例えば、アルミニウム箔)と、その両面に正極活物質を含む正極活物質層56とを有する。負極50は、負極金属箔58(例えば、銅箔)と、その両面に負極活物質を含む負極活物質層60とを有する。電極体12は、正極48と負極50との間に、これらを絶縁するセパレータ52を介在させた積層構造であり、正極48と、負極50と、セパレータ52とからなる組が複数組設けられている。   FIG. 2 is an exploded schematic perspective view showing components of the electrode body 12. As shown in FIG. 2, the electrode body 12 includes a sheet-like positive electrode 48, a sheet-like negative electrode 50, and a separator 52. The positive electrode 48 has a positive electrode metal foil 54 (for example, an aluminum foil) and a positive electrode active material layer 56 containing a positive electrode active material on both sides thereof. The negative electrode 50 includes a negative electrode metal foil 58 (for example, a copper foil) and a negative electrode active material layer 60 including a negative electrode active material on both sides thereof. The electrode body 12 has a laminated structure in which a separator 52 for insulating these is interposed between the positive electrode 48 and the negative electrode 50, and a plurality of sets of the positive electrode 48, the negative electrode 50, and the separator 52 are provided. There is.

正極48は、正極金属箔54に正極活物質が塗布されていない領域からなる正極未塗工部を有している。そして、正極48の縁部の一部には、縁部から突出した形状の正極未塗工部からなる正極タブ62が形成されている。負極50は、負極金属箔58に負極活物質が塗布されていない領域からなる負極未塗工部を有している。そして、負極50の縁部の一部には、縁部から突出した形状の負極未塗工部からなる負極タブ64が形成されている。なお、正極タブ62及び負極タブ64は、正極48及び負極50が積層された状態で、正極タブ62と負極タブ64とが重ならない位置にそれぞれ設けられている。   The positive electrode 48 has a positive electrode uncoated portion including a region where the positive electrode active material is not applied to the positive electrode metal foil 54. Then, on a part of the edge of the positive electrode 48, a positive electrode tab 62 composed of a positive electrode uncoated portion having a shape protruding from the edge is formed. The negative electrode 50 has a negative electrode uncoated portion including a region where the negative electrode active material is not applied to the negative electrode metal foil 58. Then, on a part of the edge portion of the negative electrode 50, a negative electrode tab 64 formed of a negative electrode uncoated portion having a shape protruding from the edge portion is formed. The positive electrode tab 62 and the negative electrode tab 64 are respectively provided at positions where the positive electrode tab 62 and the negative electrode tab 64 do not overlap in a state where the positive electrode 48 and the negative electrode 50 are stacked.

正極48は、それぞれの正極タブ62が電極体12の積層方向に沿って列状に配置されるように積層されている。そして、複数の正極タブ62を重ねることで正極タブ群14が形成される。また、負極50は、それぞれの負極タブ64が電極体12の積層方向に沿って列状に配置されるように積層されている。そして、複数の負極タブ64を重ねることで負極タブ群16が形成される。   The positive electrodes 48 are stacked such that the respective positive electrode tabs 62 are arranged in a row along the stacking direction of the electrode body 12. Then, the plurality of positive electrode tabs 62 are stacked to form the positive electrode tab group 14. The negative electrodes 50 are stacked such that the negative tabs 64 are arranged in a row along the stacking direction of the electrode assembly 12. The plurality of negative electrode tabs 64 are stacked to form the negative electrode tab group 16.

図1に示す正極集電部材18の具体的構成は後述するが、正極集電部材18は、一方で正極タブ群14と接続し、他方で正極内部端子38と接続しており、これにより、正極タブ群14から正極端子22へと導電させ、さらには、電極体12と正極端子22とを電気的に接続させている。負極集電部材20も同様に、一方で、負極タブ群16と接続し、他方で負極内部端子42と接続しており、これにより、負極タブ群16から負極端子24へと導電させ、さらには、電極体12と負極端子24とを電気的に接続させている。なお、正極タブ群14及び負極タブ群16とケース26内面との絶縁は、封口体30の内面に設置された絶縁部材32aにより確保されている。   Although the specific configuration of the positive electrode current collecting member 18 shown in FIG. 1 will be described later, the positive electrode current collecting member 18 is connected to the positive electrode tab group 14 on one side and connected to the positive electrode internal terminal 38 on the other side. Conductivity is made from the positive electrode tab group 14 to the positive electrode terminal 22, and furthermore, the electrode assembly 12 and the positive electrode terminal 22 are electrically connected. Similarly, the negative electrode current collecting member 20 is also connected to the negative electrode tab group 16 on the one hand and to the negative electrode internal terminal 42 on the other side, thereby causing conduction from the negative electrode tab group 16 to the negative electrode terminal 24 and further The electrode assembly 12 and the negative electrode terminal 24 are electrically connected. The insulation between the positive electrode tab group 14 and the negative electrode tab group 16 and the inner surface of the case 26 is secured by an insulating member 32 a provided on the inner surface of the sealing body 30.

以下に、正極タブ群14と正極集電部材18との接合構造について、図3を用いて説明する。なお、負極タブ群16と負極集電部材20との接合構造は、正極側と同様であるのでその説明を省略する。   Below, the junction structure of the positive electrode tab group 14 and the positive electrode current collection member 18 is demonstrated using FIG. In addition, since the joining structure of the negative electrode tab group 16 and the negative electrode current collection member 20 is the same as that of the positive electrode side, the description is abbreviate | omitted.

図3は、正極集電部材を正極タブ群に接続した電極体の模式図であり、図3(A)は、当該電極体の模式斜視図であり、図3(B)は、当該電極体の模式上面図であり、図3(C)は、当該電極体の模式側断面図である。図3(C)では、正極集電部材において、後述するタブ接続片のみを示している。図3(A)及び(B)に示すように、正極タブ群14は、電極体12の積層方向(厚み方向)に分割された第1正極タブ群66及び第2正極タブ群68を有する。そして、図3(A)及び(C)に示すように、第1正極タブ群66は、一方の最も外側の正極タブ62(H3)が、他方の最も外側の正極タブ62(H1)に近接するように重ねられている。第2正極タブ群68は、一方の最も外側の正極タブ62(H4)が、他方の最も外側にある正極タブ62(H2)に近接するように重ねられている。   FIG. 3 is a schematic view of an electrode assembly in which a positive electrode current collecting member is connected to a positive electrode tab group, FIG. 3 (A) is a schematic perspective view of the electrode assembly, and FIG. 3 (B) is the electrode assembly FIG. 3C is a schematic side cross-sectional view of the electrode assembly. In FIG. 3C, in the positive electrode current collecting member, only tab connection pieces to be described later are shown. As shown in FIGS. 3A and 3B, the positive electrode tab group 14 has a first positive electrode tab group 66 and a second positive electrode tab group 68 which are divided in the stacking direction (thickness direction) of the electrode body 12. Then, as shown in FIGS. 3A and 3C, in the first positive electrode tab group 66, one outermost positive electrode tab 62 (H3) is in proximity to the other outermost positive electrode tab 62 (H1). It is piled up to do. The second positive electrode tab group 68 is stacked such that one outermost positive electrode tab 62 (H4) is adjacent to the other outermost positive electrode tab 62 (H2).

また、図3(A)及び(B)に示すように、第1正極タブ群66及び第2正極タブ群68は、電極体12の厚み方向において対向するように配置されている。そして、図3(C)に示すように、第1正極タブ群66は、電極体12の厚み方向内側に折り曲げられた第1折曲部70aと、第1折曲部70aから電極体12の厚み方向に延在する第1延在部72aとを有する。また、第2正極タブ群68は、電極体12の厚み方向内側に折り曲げられた第2折曲部70bと、第2折曲部70bから電極体12の厚み方向に延在する第2延在部72bとを有する。なお、電極体12の厚み方向内側とは、電極体12の厚み方向の一方から他方又は他方から一方に向う方向である。   Further, as shown in FIGS. 3A and 3B, the first positive electrode tab group 66 and the second positive electrode tab group 68 are arranged to face each other in the thickness direction of the electrode body 12. Then, as shown in FIG. 3C, the first positive electrode tab group 66 includes the first bent portion 70a bent inward in the thickness direction of the electrode body 12, and the first bent portion 70a to the electrode body 12. And a first extending portion 72a extending in the thickness direction. Further, the second positive electrode tab group 68 is a second bent portion 70 b bent inward in the thickness direction of the electrode body 12 and a second extension extending in the thickness direction of the electrode body 12 from the second bent portion 70 b. And a portion 72b. The inside in the thickness direction of the electrode body 12 is a direction from one side to the other side or one side from the other in the thickness direction of the electrode body 12.

また、図3(C)に示すように、第1折曲部70a及び第2折曲部70bは、第1延在部72aと第2延在部72bが互いに近づく方向に折り曲げられている。すなわち、第1折曲部70a及び第2折曲部70bは、電極体12の厚み方向の中央に向かって折り曲げられている。   Further, as shown in FIG. 3C, the first bent portion 70a and the second bent portion 70b are bent in the direction in which the first extending portion 72a and the second extending portion 72b approach each other. That is, the first bent portion 70 a and the second bent portion 70 b are bent toward the center of the electrode body 12 in the thickness direction.

図3(A)〜(C)に示すように、正極集電部材18は、第1正極集電部材74及び第2正極集電部材76を有する。第1正極集電部材74及び第2正極集電部材76は、前述したようにクランク形状であり、屈曲部分に対して長手方向の一方側の部位であるタブ接続片(78a,78b)と、屈曲部分に対して長手方向の他方側の部位である端子接続片(80a,80b)とを有する。第1正極集電部材74及び第2正極集電部材76の端子接続片80a,80bは、前述した正極内部端子38に接続されている。   As shown to FIG. 3 (A)-(C), the positive electrode current collection member 18 has the 1st positive electrode current collection member 74 and the 2nd positive electrode current collection member 76. As shown in FIG. The first positive electrode current collecting member 74 and the second positive electrode current collecting member 76 are crank-shaped as described above, and are tab connecting pieces (78a, 78b) which are portions on one side in the longitudinal direction with respect to the bent portion; It has the terminal connection piece (80a, 80b) which is a site | part of the other side of a longitudinal direction with respect to a bending part. The terminal connection pieces 80 a and 80 b of the first positive electrode current collecting member 74 and the second positive electrode current collecting member 76 are connected to the aforementioned positive electrode internal terminal 38.

また、図3(C)に示すように、第1正極集電部材74のタブ接続片78aは、第1正極タブ群66の第1延在部72aにおける電極タブの重なり方向の一端(すなわち、正極タブ62(H3))に接続されている。ここで、第1延在部72aにおける電極タブの重なり方向の一端は、第1折曲部70aの折り曲げ方向の内周側である。すなわち、第1正極集電部材74のタブ接続片78aは、第1折曲部70aの折り曲げ方向の内周側となる、第1延在部72aにおける電極タブの重なり方向の一端に接続されている。また、第2正極集電部材76のタブ接続片78bは、第2正極タブ群68の第2延在部72bにおける電極タブの重なり方向の一端(すなわち、正極タブ62(H4))に接続されている。ここで、第2延在部72bにおける電極タブの重なり方向の一端は、第2折曲部70bの折り曲げ方向の内周側である。すなわち、第2正極集電部材76のタブ接続片78bは、第2折曲部70bの折り曲げ方向の内周側となる、第2延在部72bにおける電極タブの重なり方向の一端に接続されている。なお、第1正極集電部材74のタブ接続片78aの一端は、第1折曲部70aの内周面に当接しており、第2正極集電部材76のタブ接続片78bの一端は、第2折曲部70bの内周面に当接している。   Further, as shown in FIG. 3C, the tab connection piece 78a of the first positive electrode current collecting member 74 is one end in the overlapping direction of the electrode tabs in the first extending portion 72a of the first positive electrode tab group 66 (ie, It is connected to the positive electrode tab 62 (H3). Here, one end in the overlapping direction of the electrode tabs in the first extending portion 72a is the inner peripheral side in the bending direction of the first bent portion 70a. That is, the tab connection piece 78a of the first positive electrode current collecting member 74 is connected to one end in the overlapping direction of the electrode tab in the first extending portion 72a, which is the inner peripheral side of the bending direction of the first bent portion 70a. There is. Further, the tab connection piece 78b of the second positive electrode current collection member 76 is connected to one end (that is, the positive electrode tab 62 (H4)) in the overlapping direction of the electrode tabs in the second extending portion 72b of the second positive electrode tab group 68. ing. Here, one end in the overlapping direction of the electrode tabs in the second extending portion 72b is the inner peripheral side in the bending direction of the second bent portion 70b. That is, the tab connection piece 78b of the second positive electrode current collecting member 76 is connected to one end in the overlapping direction of the electrode tabs in the second extending portion 72b, which is the inner peripheral side of the bending direction of the second bent portion 70b. There is. One end of the tab connection piece 78a of the first positive electrode current collecting member 74 is in contact with the inner peripheral surface of the first bent portion 70a, and one end of the tab connection piece 78b of the second positive electrode current collecting member 76 is It is in contact with the inner circumferential surface of the second bent portion 70b.

第1折曲部70aの折り曲げ方向の外周側となる、第1延在部72aにおける電極タブの重なり方向の他端(すなわち、正極タブ62(H1))は、図1に示す封口体30の内面に設けられた絶縁部材32aと向かい合う面となる。また、第2折曲部70bの折り曲げ方向の外周側となる、第2延在部72bにおける電極タブの重なり方向の他端(すなわち、正極タブ62(H2))は、図1に示す封口体30の内面に設けられた絶縁部材32aと向かい合う面となる。封口体30の内面に設けられた絶縁部材32aと第1延在部72a及び第2延在部72bにおける電極タブの重なり方向の他端とは接着剤等を介して固定されていることが望ましいが、単に物理的に接触しているだけでもよい。   The other end (i.e., the positive electrode tab 62 (H1)) of the first extending portion 72a in the overlapping direction of the electrode tabs on the outer peripheral side of the first bent portion 70a in the bending direction is the sealing member 30 shown in FIG. It becomes a surface facing the insulating member 32a provided on the inner surface. In addition, the other end (i.e., positive electrode tab 62 (H2)) in the overlapping direction of the electrode tabs in the second extending portion 72b, which is the outer peripheral side of the second bent portion 70b in the bending direction, is a sealing member shown in FIG. The surface 30 faces the insulating member 32 a provided on the inner surface of the surface 30. It is desirable that the insulating member 32a provided on the inner surface of the sealing body 30 and the other end in the overlapping direction of the electrode tabs in the first extending portion 72a and the second extending portion 72b be fixed via an adhesive or the like. However, they may simply be in physical contact.

以下に、本実施形態の二次電池10の製造方法の一例を説明する。   Below, an example of the manufacturing method of the secondary battery 10 of this embodiment is demonstrated.

図4は、図3に示す電極体の製造方法の一例を説明するための図である。図4(A)に示すように、正極、セパレータ、負極からなる組を複数積層した電極体12の縁部から突出した複数の電極タブを電極体12の厚み方向(積層方向)に分割し、一方の最も外側の正極タブ62(H3)を、他方の最も外側の正極タブ62(H1)に近接するように集め、また、一方の最も外側の正極タブ62(H4)を、他方の最も外側にある正極タブ62(H2)に近接するように集める。これにより、電極体12の厚み方向において分割された第1正極タブ群66及び第2正極タブ群68となる(第1工程)。次に、図4(B)に示すように、正極タブの重なり方向における第1正極タブ群66の一端側、すなわち正極タブ62(H3)に、第1正極集電部材74のタブ接続片78aを当接させ、超音波溶接機のホーン69とアンビル71で、第1正極タブ群66及びタブ接続片78aを挟み、所定の圧力を掛けて溶接する。これにより、第1正極タブ群66と第1正極集電部材74とを電気的に接続する。また、正極タブの重なり方向における第2正極タブ群68の一端側、すなわち正極タブ62(H4)に、第2正極集電部材76のタブ接続片78bを当接させ、超音波溶接機のホーン69とアンビル71で、第2正極タブ群68及びタブ接続片78bを挟み、所定の圧力を掛けて溶接する。これにより、第2正極タブ群68と第2正極集電部材76とを電気的に接続する(第2工程)。溶接は、超音波溶接機に限定されず、抵抗溶接機等でもよい。次に、図4(C)に示すように、第1正極集電部材74のタブ接続片78aの一端を起点として、電極体12の厚み方向内側に、正極タブ群14を折り曲げ、第1折曲部70a及び第1折曲部70aから電極体12の厚み方向に延在する第1延在部72aを形成する。また、第2正極集電部材76のタブ接続片78bの一端を起点として、電極体12の厚み方向内側に、第2正極タブ群68を折り曲げ、第2折曲部70b及び第2折曲部70bから電極体12の厚み方向(積層方向)に延在する第2延在部72bを形成する(第3工程)。なお、負極側の説明は省略するが、負極側も同様に、第1工程〜第3工程を行い、負極タブ群16に負極集電部材20を接続する。   FIG. 4 is a figure for demonstrating an example of the manufacturing method of the electrode body shown in FIG. As shown in FIG. 4A, a plurality of electrode tabs projecting from the edge of the electrode body 12 in which a plurality of combinations of positive electrodes, separators and negative electrodes are stacked are divided in the thickness direction (stacking direction) of the electrode body 12, One outermost positive electrode tab 62 (H3) is collected close to the other outermost positive electrode tab 62 (H1), and one outermost positive electrode tab 62 (H4) is connected to the other outermost side. Collect close to the positive electrode tab 62 (H2). As a result, the first positive electrode tab group 66 and the second positive electrode tab group 68 divided in the thickness direction of the electrode body 12 are obtained (first step). Next, as shown in FIG. 4B, the tab connection piece 78a of the first positive electrode current collecting member 74 is provided on one end side of the first positive electrode tab group 66 in the overlapping direction of the positive electrode tabs, ie, the positive electrode tab 62 (H3). The first positive electrode tab group 66 and the tab connection piece 78a are held between the horn 69 and the anvil 71 of an ultrasonic welder, and welding is performed by applying a predetermined pressure. Thereby, the 1st positive electrode tab group 66 and the 1st positive electrode current collection member 74 are electrically connected. Further, the tab connection piece 78b of the second positive electrode current collecting member 76 is brought into contact with one end side of the second positive electrode tab group 68 in the overlapping direction of the positive electrode tabs, that is, the positive electrode tab 62 (H4), and the horn of the ultrasonic welding machine The second positive electrode tab group 68 and the tab connection piece 78b are held by the blade 69 and the anvil 71, and welding is performed by applying a predetermined pressure. Thereby, the second positive electrode tab group 68 and the second positive electrode current collecting member 76 are electrically connected (second step). The welding is not limited to the ultrasonic welding machine, and may be a resistance welding machine or the like. Next, as shown in FIG. 4C, the positive electrode tab group 14 is bent inward in the thickness direction of the electrode body 12 with one end of the tab connection piece 78a of the first positive electrode current collecting member 74 as a starting point, A first extension portion 72a extending in the thickness direction of the electrode assembly 12 is formed from the curved portion 70a and the first bent portion 70a. The second positive electrode tab group 68 is bent inward in the thickness direction of the electrode body 12 starting from one end of the tab connection piece 78b of the second positive electrode current collecting member 76 to form the second bent portion 70b and the second bent portion A second extension portion 72b extending in the thickness direction (stacking direction) of the electrode assembly 12 is formed from 70b (third step). In addition, although the description of the negative electrode side is omitted, the negative electrode side collector electrode 20 is connected to the negative electrode tab group 16 by similarly performing the first to third steps on the negative electrode side.

また、第1正極集電部材74及び第2正極集電部材76の端子接続片(80a、80b)を、封口体30に設置された正極内部端子38に接続する等して、正極端子22との導電経路を形成する。また、負極側も同様に接続し、負極端子24との導電経路を形成する。そして、電極体12等をケース26の本体部28内に収容して、本体部28と封口体30とを密閉する。そして、封口体30に設けた注液口(不図示)から電解液を注入する。以上のようにして、蓄電装置を製造する。   In addition, the terminal connection pieces (80a, 80b) of the first positive electrode current collecting member 74 and the second positive electrode current collecting member 76 are connected to the positive electrode internal terminal 38 disposed on the sealing body 30, etc. Form a conductive path of Further, the negative electrode side is similarly connected to form a conductive path with the negative electrode terminal 24. Then, the electrode body 12 and the like are accommodated in the main body portion 28 of the case 26, and the main body portion 28 and the sealing body 30 are sealed. Then, the electrolytic solution is injected from a liquid injection port (not shown) provided in the sealing body 30. As described above, a power storage device is manufactured.

本実施形態の変形例を以下に説明する。   A modification of the present embodiment will be described below.

図5は、正極集電部材を正極タブ群に接続した電極体の第1変形例を示す模式図であり、図5(A)は、当該電極体の模式斜視図であり、図5(B)は、当該電極体の模式上面図であり、図5(C)は、当該電極体の模式側断面図である。図5(C)では、正極集電部材において、タブ接続片のみを示している。図5(A)〜(C)に示すように、第1正極集電部材74のタブ接続片78aは、第1折曲部70aの折り曲げ方向の外周側となる、第1延在部72aにおける電極タブの重なり方向の他端(すなわち、正極タブ62(H1))に接続されている。また、第2正極集電部材76のタブ接続片78bは、第2折曲部70bの折り曲げ方向の外周側となる、第2延在部72bにおける電極タブの重なり方向の他端(すなわち、正極タブ62(H2))に接続されている。なお、第1正極集電部材74のタブ接続片78aにおいて、第1延在部72aとの接続面と反対側の面は、封口体30の内面に設けられた絶縁部材32aと接着剤等を介して固定されていることが望ましいが、単に物理的に接触しているだけでもよい。また、第2正極集電部材76のタブ接続片78bにおいて、第2延在部72bとの接続面と反対側の面は、封口体30の内面に設けられた絶縁部材32aと接着剤等を介して固定されていることが望ましいが、単に物理的に接触しているだけでもよい。   FIG. 5 is a schematic view showing a first modified example of the electrode assembly in which the positive electrode current collecting member is connected to the positive electrode tab group, and FIG. 5 (A) is a schematic perspective view of the electrode assembly. Is a schematic top view of the electrode assembly, and FIG. 5 (C) is a schematic side sectional view of the electrode assembly. In FIG. 5 (C), only the tab connection piece is shown in the positive electrode current collection member. As shown to FIG. 5 (A)-(C), the tab connection piece 78a of the 1st positive electrode current collection member 74 becomes an outer peripheral side of the bending direction of the 1st bending part 70a, In the 1st extension part 72a The electrode tab is connected to the other end in the overlapping direction (i.e., the positive electrode tab 62 (H1)). Further, the tab connection piece 78b of the second positive electrode current collection member 76 is the other end in the overlapping direction of the electrode tabs in the second extending portion 72b (i.e., the positive electrode) on the outer peripheral side of the second bent portion 70b in the bending direction. It is connected to the tab 62 (H2). In the tab connection piece 78a of the first positive electrode current collecting member 74, the surface on the opposite side to the connection surface with the first extending portion 72a is the insulating member 32a provided on the inner surface of the sealing member 30, an adhesive, etc. Although it is desirable to be fixed through, it may be merely in physical contact. Further, in the tab connection piece 78b of the second positive electrode current collection member 76, the surface opposite to the connection surface with the second extending portion 72b has the insulating member 32a provided on the inner surface of the sealing body 30, an adhesive agent, and the like. Although it is desirable to be fixed through, it may be merely in physical contact.

図6は、図5に示す電極体の製造方法の一例を説明するための図である。図6(A)に示すように、正極、セパレータ、負極からなる組を複数積層した電極体12の縁部から突出した複数の電極タブを電極体12の厚み方向に分割し、一方の最も外側の正極タブ62(H3)を、他方の最も外側の正極タブ62(H1)に近接するように集め、また、一方の最も外側の正極タブ62(H4)を、他方の最も外側にある正極タブ62(H2)に近接するように集める。これにより、電極体12の厚み方向において分割された第1正極タブ群66及び第2正極タブ群68となる(第1工程)。次に、図6(B)に示すように、正極タブの重なり方向における第1正極タブ群66の他端側、すなわち正極タブ62(H1)に、第1正極集電部材74のタブ接続片78aを当接させ、超音波溶接機のホーン69とアンビル71で、第1正極タブ群66およびタブ接続片78aを挟み、所定の圧力を掛けて溶接する。これにより、第1正極タブ群66と第1正極集電部材74とを電気的に接続する。また、正極タブの重なり方向における第2正極タブ群68の他端側、すなわち正極タブ62(H2)に、第2正極集電部材76のタブ接続片78bを当接させ、超音波溶接機のホーン69とアンビル71で、第2正極タブ群68及びタブ接続片78bを挟み、所定の圧力を掛けて溶接する。これにより、第2正極タブ群68と第2正極集電部材76とを電気的に接続する(第2工程)。溶接は、超音波溶接機に限定されず、抵抗溶接機等でもよい。次に、図6(C)に示すように、第1正極集電部材74のタブ接続片78aより下側で、電極体12の厚み方向内側に、正極タブ群14を折り曲げる。これにより、第1折曲部70a及び第1折曲部70aから電極体12の厚み方向(積層方向)に延在する第1延在部72aを形成する。第1正極集電部材74のタブ接続片78aより下側で折り曲げているので、第1正極集電部材74のタブ接続片78aは、第1延在部72aに位置している。また、第2正極集電部材76のタブ接続片78bより下側で、電極体12の厚み方向内側に、第2正極タブ群68を折り曲げ、第2折曲部70b及び第2折曲部70bから電極体12の厚み方向(積層方向)に延在する第2延在部72bを形成する。第2正極集電部材76のタブ接続片78bより下側で折り曲げているので、第2正極集電部材76のタブ接続片78bは、第2延在部72bに位置している(第3工程)。なお、負極側の説明は省略するが、負極側も同様に、第1工程〜第3工程を行い、負極タブ群16に負極集電部材20を接続する。   FIG. 6 is a figure for demonstrating an example of the manufacturing method of the electrode body shown in FIG. As shown in FIG. 6A, a plurality of electrode tabs protruding from the edge of the electrode body 12 in which a plurality of pairs of positive electrode, separator and negative electrode are stacked are divided in the thickness direction of the electrode body 12 and one outermost side Of one positive electrode tab 62 (H3) close to the other outermost positive electrode tab 62 (H1), and one outermost positive electrode tab 62 (H4) at the other outermost positive electrode tab Gather close to 62 (H2). As a result, the first positive electrode tab group 66 and the second positive electrode tab group 68 divided in the thickness direction of the electrode body 12 are obtained (first step). Next, as shown in FIG. 6B, the tab connection piece of the first positive electrode current collecting member 74 on the other end side of the first positive electrode tab group 66 in the overlapping direction of the positive electrode tabs, ie, the positive electrode tab 62 (H1). The first positive electrode tab group 66 and the tab connection piece 78a are held between the horn 69 and the anvil 71 of the ultrasonic welder, and welding is performed by applying a predetermined pressure. Thereby, the 1st positive electrode tab group 66 and the 1st positive electrode current collection member 74 are electrically connected. Further, the tab connection piece 78b of the second positive electrode current collector 76 is brought into contact with the other end side of the second positive electrode tab group 68 in the overlapping direction of the positive electrode tabs, that is, the positive electrode tab 62 (H2). The second positive electrode tab group 68 and the tab connection piece 78b are held by the horn 69 and the anvil 71, and welding is performed by applying a predetermined pressure. Thereby, the second positive electrode tab group 68 and the second positive electrode current collecting member 76 are electrically connected (second step). The welding is not limited to the ultrasonic welding machine, and may be a resistance welding machine or the like. Next, as shown in FIG. 6C, the positive electrode tab group 14 is bent inward in the thickness direction of the electrode body 12 below the tab connection piece 78a of the first positive electrode current collecting member 74. Thus, the first extending portion 72a extending in the thickness direction (stacking direction) of the electrode body 12 from the first bent portion 70a and the first bent portion 70a is formed. Since it is bent below the tab connection piece 78a of the first positive electrode current collection member 74, the tab connection piece 78a of the first positive electrode current collection member 74 is located in the first extending portion 72a. Further, the second positive electrode tab group 68 is bent inward in the thickness direction of the electrode body 12 below the tab connection piece 78b of the second positive electrode current collecting member 76 to form a second bent portion 70b and a second bent portion 70b. The second extending portion 72 b is formed to extend in the thickness direction (stacking direction) of the electrode body 12. The tab connection piece 78b of the second positive electrode current collection member 76 is positioned at the second extension portion 72b because the second positive electrode current collection member 76 is bent below the tab connection piece 78b (third step ). In addition, although the description of the negative electrode side is omitted, the negative electrode side collector electrode 20 is connected to the negative electrode tab group 16 by similarly performing the first to third steps on the negative electrode side.

図7は、正極集電部材を正極タブ群に接続した電極体の第2変形例を示す模式図であり、図7(A)は、当該電極体の模式斜視図であり、図7(B)は、当該電極体の模式上面図であり、図7(C)は、当該電極体の模式側断面図である。図7(C)では、正極集電部材において、タブ接続片のみを示している。図7(A)及び(B)に示すように、電極体12の厚み方向に分割された第1正極タブ群66及び第2正極タブ群68は、電極体12の厚み方向において非対向となるように、電極体12の厚み方向に対して直交する方向(電極体12の幅方向)に位置ずれした状態で配置されている。すなわち、第1正極タブ群66は、第2正極タブ群68から電極体12の幅方向に離間した位置で、電極体12の積層方向に沿って列状に配置された複数の正極タブから構成され、図7(C)に示すように、当該複数の正極タブのうち一方の最も外側の正極タブ62(H3)が、他方の最も外側の正極タブ62(H1)に近接するように重ねられている。また、第2正極タブ群68は、第1正極タブ群66から電極体12の幅方向に離間した位置で、電極体12の積層方向に沿って列状に配置された複数の正極タブから構成され、図7(C)に示すように、当該複数の正極タブのうち一方の最も外側の正極タブ62(H4)が、他方の最も外側にある正極タブ62(H2)に近接するように重ねられている。   FIG. 7 is a schematic view showing a second modified example of the electrode assembly in which the positive electrode current collecting member is connected to the positive electrode tab group, and FIG. 7 (A) is a schematic perspective view of the electrode assembly. 7 is a schematic top view of the electrode assembly, and FIG. 7 (C) is a schematic side sectional view of the electrode assembly. FIG. 7C shows only tab connection pieces in the positive electrode current collector. As shown in FIGS. 7A and 7B, the first positive electrode tab group 66 and the second positive electrode tab group 68 divided in the thickness direction of the electrode body 12 do not face each other in the thickness direction of the electrode body 12. As described above, the electrodes 12 are disposed in a position shifted in the direction (the width direction of the electrode body 12) orthogonal to the thickness direction of the electrode body 12. That is, the first positive electrode tab group 66 is configured by a plurality of positive electrode tabs arranged in a row along the stacking direction of the electrode body 12 at a position separated from the second positive electrode tab group 68 in the width direction of the electrode body 12 And as shown in FIG. 7C, the outermost positive electrode tab 62 (H3) of one of the plurality of positive electrode tabs is overlapped so as to be close to the other outermost positive electrode tab 62 (H1). ing. Further, the second positive electrode tab group 68 is configured of a plurality of positive electrode tabs arranged in a row along the stacking direction of the electrode body 12 at a position separated from the first positive electrode tab group 66 in the width direction of the electrode body 12 7C, the outermost positive electrode tab 62 (H4) of one of the plurality of positive electrode tabs is overlapped so as to be close to the other outermost positive electrode tab 62 (H2). It is done.

図7(C)に示すように、第1正極タブ群66の第1折曲部70a及び第2正極タブ群68の第2折曲部70bは、電極体12の厚み方向の内側であって、第1延在部72aと第2延在部72bが互いに近づく方向に折り曲げられている。すなわち、第1折曲部70a及び第2折曲部70bは、電極体12の積層方向(厚み方向)の中央に向かって折り曲げられている。   As shown in FIG. 7C, the first bent portion 70a of the first positive electrode tab group 66 and the second bent portion 70b of the second positive electrode tab group 68 are inside of the electrode body 12 in the thickness direction. The first extending portion 72a and the second extending portion 72b are bent in directions approaching each other. That is, the first bent portion 70 a and the second bent portion 70 b are bent toward the center in the stacking direction (thickness direction) of the electrode body 12.

図7(C)に示すように、第1正極集電部材74のタブ接続片78aは、第1折曲部70aの折り曲げ方向の内周側となる、第1延在部72aにおける電極タブの重なり方向の一端(すなわち、正極タブ62(H3))に接続されている。また、第2正極集電部材76のタブ接続片78bは、第2折曲部70bの折り曲げ方向の内周側となる、第2延在部72bにおける電極タブの重なり方向の一端(すなわち、正極タブ62(H4))に接続されている。   As shown in FIG. 7C, the tab connection piece 78a of the first positive electrode current collecting member 74 is an inner peripheral side of the first bent portion 70a in the bending direction of the electrode tab in the first extending portion 72a. It is connected to one end in the overlapping direction (that is, the positive electrode tab 62 (H3)). In addition, the tab connection piece 78b of the second positive electrode current collection member 76 is one end in the overlapping direction of the electrode tabs in the second extending portion 72b (ie, the positive electrode) on the inner peripheral side of the bending direction of the second bent portion 70b. It is connected to the tab 62 (H4).

図での説明は省略するが、第1正極集電部材74のタブ接続片78aは、第1折曲部70aの折り曲げ方向の外周側となる、第1延在部72aにおける電極タブの重なり方向の他端(すなわち、正極タブ62(H1))に接続されていてもよい。また、第2正極集電部材76のタブ接続片78bは、第2折曲部70bの折り曲げ方向の外周側となる、第2延在部72bにおける電極タブの重なり方向の他端(すなわち、正極タブ62(H2))に接続されていてもよい。   Although the description in the drawings is omitted, the tab connecting piece 78a of the first positive electrode current collecting member 74 is the outer peripheral side of the first bent portion 70a in the bending direction, and the overlapping direction of the electrode tabs in the first extending portion 72a May be connected to the other end (i.e., the positive electrode tab 62 (H1)). Further, the tab connection piece 78b of the second positive electrode current collection member 76 is the other end in the overlapping direction of the electrode tabs in the second extending portion 72b (i.e., the positive electrode) on the outer peripheral side of the second bent portion 70b in the bending direction. It may be connected to the tab 62 (H2)).

図8は、図7に示す電極体の製造方法の一例を説明するための図である。図8(A)に示すように、正極、セパレータ、負極からなる組を複数積層した電極体12の縁部から突出した複数の電極タブの一方の最も外側の正極タブ62(H3)を、他方の最も外側の正極タブ62(H1)に近接するように集め、また、上記複数の電極タブとは電極体12の幅方向において離間した位置にある複数の電極タブの一方の最も外側の正極タブ62(H4)を、他方の最も外側にある正極タブ62(H2)に近接するように集める。これにより、電極体12の厚み方向において分割され、且つ非対向となるように配置された第1正極タブ群66及び第2正極タブ群68となる(第1工程)。次に、図8(B)に示すように、正極タブの重なり方向における第1正極タブ群66の一端側、すなわち正極タブ62(H3)に、第1正極集電部材74のタブ接続片78aを当接させ、超音波溶接機のホーン69とアンビル71で、第1正極タブ群66及びタブ接続片78aを挟み、所定の圧力を掛けて溶接する。これにより、第1正極タブ群66と第1正極集電部材74とを電気的に接続する。また、正極タブの重なり方向における第2正極タブ群68の一端側、すなわち正極タブ62(H4)に、第2正極集電部材76のタブ接続片78bを当接させ、超音波溶接機のホーン69とアンビル71で、第2正極タブ群68及びタブ接続片78bを挟み、所定の圧力を掛けて溶接する。これにより、第2正極タブ群68と第2正極集電部材76とを電気的に接続する(第2工程)。溶接は、超音波溶接機に限定されず、抵抗溶接機等でもよい。次に、図8(C)に示すように、第1正極集電部材74のタブ接続片78aの一端を起点として、電極体12の厚み方向内側に、第1正極タブ群66を折り曲げ、第1折曲部70a及び第1折曲部70aから電極体12の厚み方向に延在する第1延在部72aを形成する。また、第2正極集電部材76のタブ接続片78bの一端を起点として、電極体12の厚み方向内側に、第2正極タブ群68を折り曲げ、第2折曲部70b及び第2折曲部70bから電極体12の厚み方向に延在する第2延在部72bを形成する(第3工程)。なお、負極側の説明は省略するが、負極側も同様に、第1工程〜第3工程を行い、負極タブ群16に負極集電部材20を接続する。   FIG. 8 is a figure for demonstrating an example of the manufacturing method of the electrode body shown in FIG. As shown in FIG. 8A, one of the outermost positive electrode tabs 62 (H3) of the plurality of electrode tabs protruding from the edge of the electrode body 12 in which a plurality of combinations of positive electrodes, separators and negative electrodes are stacked, Of the outermost electrode tabs 62 (H1), and the outermost electrode tabs of one of the plurality of electrode tabs spaced apart in the width direction of the electrode assembly 12 from the plurality of electrode tabs. 62 (H4) is collected close to the other outermost positive electrode tab 62 (H2). As a result, the first positive electrode tab group 66 and the second positive electrode tab group 68 which are divided in the thickness direction of the electrode body 12 and arranged so as not to face each other are formed (first step). Next, as shown in FIG. 8B, a tab connection piece 78a of the first positive electrode current collecting member 74 is provided on one end side of the first positive electrode tab group 66 in the overlapping direction of the positive electrode tabs, that is, the positive electrode tab 62 (H3). The first positive electrode tab group 66 and the tab connection piece 78a are held between the horn 69 and the anvil 71 of an ultrasonic welder, and welding is performed by applying a predetermined pressure. Thereby, the 1st positive electrode tab group 66 and the 1st positive electrode current collection member 74 are electrically connected. Further, the tab connection piece 78b of the second positive electrode current collecting member 76 is brought into contact with one end side of the second positive electrode tab group 68 in the overlapping direction of the positive electrode tabs, that is, the positive electrode tab 62 (H4), and the horn of the ultrasonic welding machine The second positive electrode tab group 68 and the tab connection piece 78b are held by the blade 69 and the anvil 71, and welding is performed by applying a predetermined pressure. Thereby, the second positive electrode tab group 68 and the second positive electrode current collecting member 76 are electrically connected (second step). The welding is not limited to the ultrasonic welding machine, and may be a resistance welding machine or the like. Next, as shown in FIG. 8C, the first positive electrode tab group 66 is bent inward in the thickness direction of the electrode body 12 with one end of the tab connection piece 78a of the first positive electrode current collecting member 74 as a starting point. A first extending portion 72a extending in the thickness direction of the electrode body 12 is formed from the first bent portion 70a and the first bent portion 70a. The second positive electrode tab group 68 is bent inward in the thickness direction of the electrode body 12 starting from one end of the tab connection piece 78b of the second positive electrode current collecting member 76 to form the second bent portion 70b and the second bent portion A second extension portion 72b extending in the thickness direction of the electrode assembly 12 from 70b is formed (third step). In addition, although the description of the negative electrode side is omitted, the negative electrode side collector electrode 20 is connected to the negative electrode tab group 16 by similarly performing the first to third steps on the negative electrode side.

図9は、正極集電部材を正極タブ群に接続した電極体の第3変形例を示す模式図であり、図9(A)は、当該電極体の模式斜視図であり、図9(B)は、当該電極体の模式上面図であり、図9(C)は、当該電極体の模式側断面図である。図9(C)では、正極集電部材において、タブ接続片のみを示している。図9(A)及び(B)に示すように、電極体12の厚み方向に分割された第1正極タブ群66及び第2正極タブ群68は、電極体12の厚み方向において非対向となるように、電極体12の厚み方向に対して直交する方向(電極体12の幅方向)に位置ずれした状態で配置されている。すなわち、第1正極タブ群66は、第2正極タブ群68から電極体12の幅方向に離間した位置で、電極体12の積層方向に沿って列状に配置された複数の正極タブから構成され、図9(C)に示すように、当該複数の正極タブのうち一方の最も外側の正極タブ62(H3)が、他方の最も外側の正極タブ62(H1)に近接するように重ねられている。また、第2正極タブ群68は、第1正極タブ群66から電極体12の幅方向に離間した位置で、電極体12の積層方向に沿って列状に配置された複数の正極タブから構成され、図9(C)に示すように、当該複数の正極タブのうち一方の最も外側の正極タブ62(H2)が、他方の最も外側にある正極タブ62(H4)に近接するように重ねられている。   FIG. 9 is a schematic view showing a third modified example of the electrode assembly in which the positive electrode current collecting member is connected to the positive electrode tab group, and FIG. 9 (A) is a schematic perspective view of the electrode assembly. Fig. 9 is a schematic top view of the electrode assembly, and Fig. 9 (C) is a schematic side sectional view of the electrode assembly. In FIG. 9C, only the tab connection pieces are shown in the positive electrode current collecting member. As shown in FIGS. 9A and 9B, the first positive electrode tab group 66 and the second positive electrode tab group 68 divided in the thickness direction of the electrode body 12 do not face each other in the thickness direction of the electrode body 12. As described above, the electrodes 12 are disposed in a position shifted in the direction (the width direction of the electrode body 12) orthogonal to the thickness direction of the electrode body 12. That is, the first positive electrode tab group 66 is configured by a plurality of positive electrode tabs arranged in a row along the stacking direction of the electrode body 12 at a position separated from the second positive electrode tab group 68 in the width direction of the electrode body 12 9C, the outermost positive electrode tab 62 (H3) of one of the plurality of positive electrode tabs is overlapped so as to be close to the other outermost positive electrode tab 62 (H1). ing. Further, the second positive electrode tab group 68 is configured of a plurality of positive electrode tabs arranged in a row along the stacking direction of the electrode body 12 at a position separated from the first positive electrode tab group 66 in the width direction of the electrode body 12 And as shown in FIG. 9C, the outermost positive electrode tab 62 (H2) of one of the plurality of positive electrode tabs overlaps the other outermost positive electrode tab 62 (H4). It is done.

図9(A)及び(C)に示すように、第1正極タブ群66の第1折曲部70a及び第2正極タブ群68の第2折曲部70bは、電極体12の厚み方向内側であって、第1延在部72aと第2延在部72bが同じ方向に延在するように折り曲げられている。すなわち、第1折曲部70a及び第2折曲部70bは、電極体12の積層方向(厚み方向)の一方から他方に向ってそれぞれ折り曲げられている。   As shown in FIGS. 9A and 9C, the first bent portion 70a of the first positive electrode tab group 66 and the second bent portion 70b of the second positive electrode tab group 68 are formed on the inner side in the thickness direction of the electrode body 12. The first extension 72a and the second extension 72b are bent so as to extend in the same direction. That is, the first bending portion 70 a and the second bending portion 70 b are respectively bent from one side to the other side in the stacking direction (thickness direction) of the electrode body 12.

図9(C)に示すように、第1正極集電部材74のタブ接続片78aは、第1折曲部70aの折り曲げ方向の内周側となる、第1延在部72aにおける電極タブの重なり方向の一端(すなわち、正極タブ62(H3))に接続されている。また、第2正極集電部材76のタブ接続片78bは、第2折曲部70bの折り曲げ方向の内周側となる、第2延在部72bにおける電極タブの重なり方向の一端(すなわち、正極タブ62(H2))に接続されている。   As shown in FIG. 9C, the tab connection piece 78a of the first positive electrode current collecting member 74 is an inner peripheral side of the first bent portion 70a in the bending direction of the electrode tab in the first extending portion 72a. It is connected to one end in the overlapping direction (that is, the positive electrode tab 62 (H3)). In addition, the tab connection piece 78b of the second positive electrode current collection member 76 is one end in the overlapping direction of the electrode tabs in the second extending portion 72b (ie, the positive electrode) on the inner peripheral side of the bending direction of the second bent portion 70b. It is connected to the tab 62 (H2).

図での説明は省略するが、第1正極集電部材74のタブ接続片78aは、第1折曲部70aの折り曲げ方向の外周側となる、第1延在部72aにおける電極タブの重なり方向の他端(すなわち、正極タブ62(H1))に接続されていてもよい。また、第2正極集電部材76のタブ接続片78bは、第2折曲部70bの折り曲げ方向の外周側となる、第2延在部72bにおける電極タブの重なり方向の他端(すなわち、正極タブ62(H4))に接続されていてもよい。   Although the description in the drawings is omitted, the tab connecting piece 78a of the first positive electrode current collecting member 74 is the outer peripheral side of the first bent portion 70a in the bending direction, and the overlapping direction of the electrode tabs in the first extending portion 72a May be connected to the other end (i.e., the positive electrode tab 62 (H1)). Further, the tab connection piece 78b of the second positive electrode current collection member 76 is the other end in the overlapping direction of the electrode tabs in the second extending portion 72b (i.e., the positive electrode) on the outer peripheral side of the second bent portion 70b in the bending direction. It may be connected to the tab 62 (H4)).

図10は、図9に示す電極体の製造方法の一例を説明するための図である。図10(A)に示すように、正極、セパレータ、負極からなる組を複数積層した電極体12の縁部から突出した複数の電極タブの一方の最も外側の正極タブ62(H3)を、他方の最も外側の正極タブ62(H1)に近接するように集め、また、上記複数の電極タブとは電極体12の幅方向において離間した位置にある複数の電極タブの一方の最も外側の正極タブ62(H2)を、他方の最も外側にある正極48タブ(H4)に近接するように集める。これにより、電極体12の厚み方向において分割され、且つ非対向となるように配置された第1正極タブ群66及び第2正極タブ群68となる(第1工程)。次に、図10(B)に示すように、正極タブの重なり方向における第1正極タブ群66の一端側、すなわち正極タブ62(H3)に、第1正極集電部材74のタブ接続片78aを当接させ、超音波溶接機のホーン69とアンビル71で、第1正極タブ群66及びタブ接続片78aを挟み、所定の圧力を掛けて溶接する。これにより、第1正極タブ群66と第1正極集電部材74とを電気的に接続する。また、正極タブの重なり方向における第2正極タブ群68の一端側、すなわち正極タブ62(H4)に、第2正極集電部材76のタブ接続片78bを当接させ、超音波溶接機のホーン69とアンビル71で、第2正極タブ群68及びタブ接続片78bを挟み、所定の圧力を掛けて溶接する。これにより、第2正極タブ群68と第2正極集電部材76とを電気的に接続する(第2工程)。溶接は、超音波溶接機に限定されず、抵抗溶接機等でもよい。次に、図10(C)に示すように、第1正極集電部材74のタブ接続片78aの一端を起点として、電極体12の厚み方向内側に、第1正極タブ群66を折り曲げ、第1折曲部70a及び第1折曲部70aから電極体12の厚み方向(積層方向)に延在する第1延在部72aを形成する。また、第2正極集電部材76のタブ接続片78bの一端を起点として、電極体12の厚み方向内側に、第2正極タブ群68を折り曲げ、第2折曲部70b及び第2折曲部70bから電極体12の厚み方向(積層方向)に延在する第2延在部72bを形成する(第3工程)。なお、負極側の説明は省略するが、負極側も同様に、第1工程〜第3工程を行い、負極タブ群16に負極集電部材20を接続する。   FIG. 10 is a diagram for explaining an example of a method of manufacturing the electrode body shown in FIG. As shown in FIG. 10A, one of the outermost positive electrode tabs 62 (H3) of the plurality of electrode tabs protruding from the edge of the electrode body 12 in which a plurality of pairs of positive electrodes, separators and negative electrodes are stacked, Of the outermost electrode tabs 62 (H1), and the outermost electrode tabs of one of the plurality of electrode tabs spaced apart in the width direction of the electrode assembly 12 from the plurality of electrode tabs. 62 (H2) is collected close to the other outermost positive electrode 48 tab (H4). As a result, the first positive electrode tab group 66 and the second positive electrode tab group 68 which are divided in the thickness direction of the electrode body 12 and arranged so as not to face each other are formed (first step). Next, as shown in FIG. 10B, the tab connection piece 78a of the first positive electrode current collecting member 74 is provided on one end side of the first positive electrode tab group 66 in the overlapping direction of the positive electrode tabs, that is, the positive electrode tab 62 (H3). The first positive electrode tab group 66 and the tab connection piece 78a are held between the horn 69 and the anvil 71 of an ultrasonic welder, and welding is performed by applying a predetermined pressure. Thereby, the 1st positive electrode tab group 66 and the 1st positive electrode current collection member 74 are electrically connected. Further, the tab connection piece 78b of the second positive electrode current collecting member 76 is brought into contact with one end side of the second positive electrode tab group 68 in the overlapping direction of the positive electrode tabs, that is, the positive electrode tab 62 (H4), and the horn of the ultrasonic welding machine The second positive electrode tab group 68 and the tab connection piece 78b are held by the blade 69 and the anvil 71, and welding is performed by applying a predetermined pressure. Thereby, the second positive electrode tab group 68 and the second positive electrode current collecting member 76 are electrically connected (second step). The welding is not limited to the ultrasonic welding machine, and may be a resistance welding machine or the like. Next, as shown in FIG. 10C, the first positive electrode tab group 66 is bent inward in the thickness direction of the electrode body 12 with one end of the tab connection piece 78a of the first positive electrode current collecting member 74 as a starting point. A first extension portion 72a extending in the thickness direction (stacking direction) of the electrode body 12 is formed from the first bent portion 70a and the first bent portion 70a. The second positive electrode tab group 68 is bent inward in the thickness direction of the electrode body 12 starting from one end of the tab connection piece 78b of the second positive electrode current collecting member 76 to form the second bent portion 70b and the second bent portion A second extension portion 72b extending in the thickness direction (stacking direction) of the electrode assembly 12 is formed from 70b (third step). In addition, although the description of the negative electrode side is omitted, the negative electrode side collector electrode 20 is connected to the negative electrode tab group 16 by similarly performing the first to third steps on the negative electrode side.

以上説明した、本実施形態によれば以下の効果を得ることが可能である。以下に述べる電極は正極及び負極の両方を指しており、例えば、電極タブ群と言えば、正極タブ群及び負極タブ群を指している。   According to the embodiment described above, the following effects can be obtained. The electrodes described below refer to both the positive electrode and the negative electrode, and, for example, the term “electrode tab group” refers to the positive electrode tab group and the negative electrode tab group.

本実施形態では、電極タブ群が電極体の厚み方向において分割された第1電極タブ群及び第2電極タブ群で構成され、第1電極タブ群及び第2電極タブ群が、電極体の厚み方向内側に折り曲げられている。これにより、集電部材を内側に折り曲げる構成のため電極タブ群が配置されるケース内のデッドスペースが削減される。さらに、電極体の厚み方向において分割していない電極タブ群を電極体の厚み方向内側に折り曲げた場合と比較して、電極タブ群の厚みが薄くなるため、電極タブ群が配置されるケース内のデッドスペースが削減される。また、電極タブ群の厚みが薄くなるため、集電部材との電気的な接続を低エネルギーで行うことが可能となり、接続時に金属異物の発生等が抑制される。   In the present embodiment, the electrode tab group is composed of the first electrode tab group and the second electrode tab group divided in the thickness direction of the electrode body, and the first electrode tab group and the second electrode tab group have the thickness of the electrode body. It is bent inward. Thereby, the dead space in the case where the electrode tab group is disposed is reduced because the current collection member is bent inward. Furthermore, since the thickness of the electrode tab group becomes thinner compared to the case where the electrode tab group not divided in the thickness direction of the electrode body is bent inward in the thickness direction of the electrode body, in the case where the electrode tab group is arranged Dead space is reduced. In addition, since the thickness of the electrode tab group is reduced, electrical connection with the current collection member can be performed with low energy, and generation of metallic foreign matter and the like can be suppressed at the time of connection.

図3に示すような、電極集電部材が、折曲部の折り曲げ方向の内周側となる、延在部における電極タブの重なり方向の一端に接続されている方が、図5に示すような、電極集電部材が、折曲部の折り曲げ方向の外周側となる、延在部における電極タブの重なり方向の他端に接続される場合と比較して、電極タブ群の延びが抑制されるため、電極体の移動が抑えられる。これにより、電極体がケース内面と接触することが抑えられるため、電極体を構成する電極の折れ曲り、電極を構成する活物質の脱落による電池性能の低下が抑制される。   As shown in FIG. 5, the electrode current collecting member as shown in FIG. 3 is connected to one end in the overlapping direction of the electrode tabs in the extending portion which is the inner peripheral side of the bending direction in the bending direction as shown in FIG. 5. The extension of the electrode tab group is suppressed as compared with the case where the electrode current collecting member is connected to the other end of the extension portion in the overlapping direction of the electrode tabs on the outer peripheral side of the bending portion in the bending direction. Therefore, the movement of the electrode body can be suppressed. As a result, the contact of the electrode body with the inner surface of the case is suppressed, so that deterioration of the battery performance due to bending of the electrode constituting the electrode body and dropping of the active material constituting the electrode is suppressed.

一般的に、電極体の厚み方向に分割された第1及び第2電極タブ群の延在部が重なっていると、重なった部分が厚くなりデッドスペースとなり易い。ここで、図3及び5に示すように、電極体の積層方向に分割された第1電極タブ群及び第2電極タブ群が、電極体の厚み方向において対向するように配置されている場合、各電極タブ群が電極体の縁部近くで折り曲げられると、各電極タブ群の延在部が互いに重なる場合ある。一方、図7及び図9に示すように、電極体の厚み方向に分割された第1電極タブ群及び第2電極タブ群が、電極体の厚み方向において非対向となるように配置されている場合、各電極タブ群が電極体の縁部近くで折り曲げられても、各電極タブ群の延在部が互いに重なることがない。したがって、図7及び図9に示すように、電極体の厚み方向に分割された第1電極タブ群及び第2電極タブ群が、電極体の厚み方向において非対向となるように配置されている方が、電極タブ群の高さを低くすることができるため、電極タブ群が配置されるケース内のデッドスペースがより削減される。   In general, when the extension portions of the first and second electrode tab groups divided in the thickness direction of the electrode body overlap, the overlapping portion becomes thick and tends to be a dead space. Here, as shown in FIGS. 3 and 5, when the first electrode tab group and the second electrode tab group divided in the stacking direction of the electrode assembly are arranged to face each other in the thickness direction of the electrode assembly, When the electrode tab groups are folded near the edge of the electrode body, the extensions of the electrode tab groups may overlap each other. On the other hand, as shown in FIGS. 7 and 9, the first electrode tab group and the second electrode tab group divided in the thickness direction of the electrode body are arranged so as not to face each other in the thickness direction of the electrode body. In the case where the electrode tab groups are bent near the edge of the electrode body, the extensions of the electrode tab groups do not overlap with each other. Therefore, as shown in FIGS. 7 and 9, the first electrode tab group and the second electrode tab group divided in the thickness direction of the electrode body are arranged so as not to face each other in the thickness direction of the electrode body. Since the height of the electrode tabs can be reduced, the dead space in the case in which the electrode tabs are arranged is further reduced.

図7及び図9に示すように、電極体の厚み方向に分割され、非対向となるように配置される第1電極タブ群及び第2電極タブ群を形成する場合、例えば、電極タブが電極の幅方向において異なる位置にある2つの電極を用意する必要がある。一方、図3及び5に示すように、電極体の厚み方向に分割され、電極体の厚み方向において対向するように配置される第1電極タブ群及び第2電極タブ群を形成する場合、電極タブが形成された1つの電極を用意すればよい。したがって、図3及び5に示すように、電極体の厚み方向に分割され、電極体の厚み方向において対向するように配置される第1電極タブ群及び第2電極タブ群の方が、例えば、二次電池の作製が容易となる。   As shown in FIGS. 7 and 9, when forming the first electrode tab group and the second electrode tab group which are divided in the thickness direction of the electrode body and arranged so as not to face each other, for example, the electrode tabs are electrodes It is necessary to prepare two electrodes at different positions in the width direction of. On the other hand, as shown in FIGS. 3 and 5, when forming the first electrode tab group and the second electrode tab group which are divided in the thickness direction of the electrode body and arranged to face each other in the thickness direction of the electrode body, It suffices to prepare one electrode having a tab formed thereon. Therefore, as shown in FIGS. 3 and 5, the first electrode tab group and the second electrode tab group which are divided in the thickness direction of the electrode body and arranged to face each other in the thickness direction of the electrode body are, for example, The fabrication of the secondary battery is facilitated.

実施形態は、上記に限定されるものではなく、本開示の効果を損なわない範囲において変形することが可能である。   Embodiments are not limited to the above, and may be modified as long as the effects of the present disclosure are not impaired.

例えば、蓄電装置は、リチウムイオン電池に限定されるものではなく、ニッケル水素電池等の他の種類の電池でもよいし、電気二重層キャパシタ等のようなキャパシタやその他の蓄電素子でもよい。また、例えば、電極体は積層型に限定されるものではなく、巻回型の電極体であってもよい。   For example, the storage device is not limited to a lithium ion battery, and may be another type of battery such as a nickel hydrogen battery, a capacitor such as an electric double layer capacitor, or another storage device. Also, for example, the electrode body is not limited to the laminated type, and may be a wound type electrode body.

正極タブ及び負極タブは、正極未塗工部及び負極未塗工部からなるものに限定されるものではなく、例えば、それぞれの電極に溶接した金属箔を正極タブ及び負極タブとしてもよい。   The positive electrode tab and the negative electrode tab are not limited to those composed of the positive electrode uncoated part and the negative electrode uncoated part, and for example, metal foils welded to the respective electrodes may be used as the positive electrode tab and the negative electrode tab.

正極集電部材の形状は、クランク形状に限定されるものではなく、正極タブ群から正極端子へと導電させることができる形状であればどのような形状であってもよい。負極集電部材も同様である。   The shape of the positive electrode current collection member is not limited to the crank shape, and may be any shape as long as it can be made conductive from the positive electrode tab group to the positive electrode terminal. The same applies to the negative electrode current collector.

第1正極タブ群の第1延在部と第1正極集電部材との接続、及び第2正極タブ群の第2延在部と第2正極集電部材との接続は、超音波溶接や抵抗溶接に限定されるものではなく、例えば、レーザー溶接等でもよい。第1正極集電部材及び第2正極集電部材は、第1延在部及び第2延在部における正極タブの厚み方向の一端又は他端側であればどこに溶接されてもよいが、特に、折り曲げられた全ての正極タブが重なる延在部の一端又は他端に溶接されることが好ましい。負極タブ群と負極集電部材との接続も同様である。   The connection between the first extending portion of the first positive electrode tab group and the first positive electrode current collecting member, and the connection between the second extending portion of the second positive electrode tab group and the second positive electrode current collecting member are ultrasonic welding or The invention is not limited to resistance welding, and may be, for example, laser welding. The first positive current collecting member and the second positive current collecting member may be welded anywhere as long as one end or the other end side in the thickness direction of the positive electrode tab in the first extending portion and the second extending portion Preferably, all the bent positive electrode tabs are welded to one end or the other end of the overlapping extension. The connection between the negative electrode tab group and the negative electrode current collector is the same.

第1正極タブ群の第1延在部及び第2正極タブ群の第2延在部は、電極体の厚み方向に平行に延在していてもよいし、電極体の厚み方向に対して傾斜するように延在していてもよい。電極体の厚み方向に対する第1延在部及び第2延在部の傾斜角度は例えば、0°〜10°以下が好ましく、0°〜2°以下がより好ましい。負極タブ群の延在部も同様である。   The first extending portion of the first positive electrode tab group and the second extending portion of the second positive electrode tab group may extend in parallel with the thickness direction of the electrode body, or in the thickness direction of the electrode body It may extend to be inclined. The inclination angle of the first extending portion and the second extending portion with respect to the thickness direction of the electrode body is, for example, preferably 0 ° to 10 ° or less, and more preferably 0 ° to 2 ° or less. The same applies to the extension of the negative electrode tab group.

第1正極タブ群及び第2正極タブ群は、電極体の積層方向(厚み方向)の一端から他端までの範囲内に位置する正極タブの全枚数のうち、均等の枚数の正極タブをそれぞれ有していてもよいし、異なる枚数の正極タブをそれぞれ有していてもよい。負極タブ群も同様である。   The first positive electrode tab group and the second positive electrode tab group each have an equal number of positive electrode tabs out of the total number of positive electrode tabs located in the range from one end to the other end in the stacking direction (thickness direction) of the electrode assembly. You may have, and you may each have a different number of positive electrode tabs. The same applies to the negative electrode tab group.

第1正極タブ群と第2正極タブ群の対向配置は、電極体の積層方向から見て、第1正極電極タブ群と第2正極タブ群とが完全に重なっている場合に限定されるものではなく、少なくとも一部が重なっていればよい。また、第1正極タブ群と第2正極タブ群の非対向配置は、電極体の積層方向から見て、第1正極タブ群と第2正極タブ群が重なっていなければよく、電極体の幅方向に離間する距離は特に制限されるものではない。負極タブ群も同様である。   The facing arrangement of the first positive electrode tab group and the second positive electrode tab group is limited to the case where the first positive electrode tab group and the second positive electrode tab group completely overlap with each other when viewed from the stacking direction of the electrode assembly. Rather, it is sufficient if at least part of them overlap. In the non-opposing arrangement of the first positive electrode tab group and the second positive electrode tab group, it is preferable that the first positive electrode tab group and the second positive electrode tab group do not overlap when viewed from the stacking direction of the electrode body, and the width of the electrode body The distance separating in the direction is not particularly limited. The same applies to the negative electrode tab group.

電極体の積層方向に分割され、電極体の厚み方向において対向するように配置されている第1電極タブ群及び第2電極タブ群において、第1電極タブ群の第1延在部と第2電極タブ群の第2延在部とが重ならないように隙間を設けることが望ましいが、第1電極タブ群の第1延在部と第2電極タブ群の第2延在部とが重なっていてもよい。   In the first electrode tab group and the second electrode tab group which are divided in the stacking direction of the electrode body and arranged to face each other in the thickness direction of the electrode body, the first extension portion and the second extension portion of the first electrode tab group It is desirable to provide a gap so that the second extension of the electrode tab group does not overlap, but the first extension of the first electrode tab group and the second extension of the second electrode tab group overlap. May be

第1正極タブ群及び第2正極タブ群の2つの正極タブ群に限定されるものではなく、電極体の厚み方向に分割された3つ以上の正極タブ群であってもよい。負極タブ群も同様である。   The present invention is not limited to the two positive electrode tab groups of the first positive electrode tab group and the second positive electrode tab group, and may be three or more positive electrode tab groups divided in the thickness direction of the electrode body. The same applies to the negative electrode tab group.

10 二次電池、12 電極体、14 正極タブ群、16 負極タブ群、18 正極集電部材、20 負極集電部材、22 正極端子、24 負極端子、26 ケース、28 本体部、30 封口体、32a,32b 絶縁部材、34 金属基板、36 正極外部端子、38 正極内部端子、40 負極外部端子、42 負極内部端子、44 金属板、46 リベット部、48 正極、50 負極、52 セパレータ、54 正極金属箔、56正極活物質層、58 負極金属箔、60 負極活物質層、62 正極タブ、64 負極タブ、66 第1正極タブ群、68 第2正極タブ群、69 ホーン、70a 第1折曲部、70b 第2折曲部、71 アンビル、72a 第1延在部、72b 第2延在部、74 第1正極集電部材、76 第2正極集電部材、78a,78b タブ接続片、80a,80b 端子接続片。   DESCRIPTION OF SYMBOLS 10 Secondary battery, 12 electrode body, 14 positive electrode tab group, 16 negative electrode tab group, 18 positive electrode current collection member, 20 negative electrode current collection member, 22 positive electrode terminal, 24 negative electrode terminal, 26 cases, 28 body parts, 30 sealing members, 32a, 32b insulating members, 34 metal substrates, 36 positive external terminals, 38 positive internal terminals, 40 negative external terminals, 42 negative internal terminals, 44 metal plates, 46 rivets, 48 positive electrodes, 50 negative electrodes, 52 separators, 54 positive metal Foil, 56 positive electrode active material layer, 58 negative electrode metal foil, 60 negative electrode active material layer, 62 positive electrode tab, 64 negative electrode tab, 66 first positive electrode tab group, 68 second positive electrode tab group, 69 horn, 70a first bent portion , 70b second bent portion, 71 anvil, 72a first extending portion, 72b second extending portion, 74 first positive electrode current collecting member, 76 second positive electrode current collecting member, 78a 78b tab connection piece, 80a, 80b terminal connection piece.

Claims (6)

電極体と、
前記電極体の縁部から突出した複数の電極タブを重ねた電極タブ群と、
前記電極体との間で電気を授受する電極端子と、
前記電極タブ群に接続され、前記電極タブ群から前記電極端子へと導電させる集電部材と、を有する蓄電装置であって、
前記電極タブ群は、前記電極体の厚み方向において分割された第1電極タブ群と第2電極タブ群とを有し、
前記第1電極タブ群は、前記電極体の厚み方向内側に折り曲げられた第1折曲部と、前記第1折曲部から前記電極体の厚み方向に延在する第1延在部と、を有し、
前記第2電極タブ群は、前記電極体の厚み方向内側に折り曲げられた第2折曲部と、前記第2折曲部から前記電極体の厚み方向に延在する第2延在部と、を有し、
前記集電部材は、前記第1延在部における前記電極タブの重なり方向の一端又は他端に接続された第1集電部材と、前記第2延在部における前記電極タブの重なり方向の一端又は他端に接続された第2集電部材と、を有する、蓄電装置。
Electrode body,
An electrode tab group in which a plurality of electrode tabs projecting from an edge of the electrode body are overlapped;
An electrode terminal for exchanging electricity with the electrode body;
And a current collecting member connected to the electrode tab group to conduct electricity from the electrode tab group to the electrode terminal,
The electrode tab group has a first electrode tab group and a second electrode tab group divided in the thickness direction of the electrode body,
The first electrode tab group includes a first bent portion bent inward in a thickness direction of the electrode body, and a first extension portion extending in the thickness direction of the electrode body from the first bent portion. Have
The second electrode tab group includes a second bent portion bent inward in a thickness direction of the electrode body, and a second extension portion extending in the thickness direction of the electrode body from the second bent portion. Have
The current collecting member is a first current collecting member connected to one end or the other end of the first extending portion in the overlapping direction of the electrode tabs, and one end of the electrode tab in the second extending portion in the overlapping direction Or a second current collecting member connected to the other end.
前記第1延在部の前記一端は、前記第1折曲部の折り曲げ方向の内周側であり、前記第1集電部材は前記第1延在部の前記一端に接続され、
前記第2延在部の前記一端は、前記第2折曲部の折り曲げ方向の内周側であり、前記第2集電部材は前記第1延在部の前記一端に接続されている、請求項1に記載の蓄電装置。
The one end of the first extending portion is an inner peripheral side in the bending direction of the first bent portion, and the first current collecting member is connected to the one end of the first extending portion.
The one end of the second extending portion is an inner peripheral side in the bending direction of the second bent portion, and the second current collecting member is connected to the one end of the first extending portion. The power storage device according to Item 1.
前記第1電極タブ群と前記第2電極タブ群は、前記電極体の厚み方向において対向するように配置されており、
前記第1折曲部及び前記第2折曲部は、前記第1延在部と前記第2延在部が互いに近づく方向に折り曲げられている、請求項1又は2に記載の蓄電装置。
The first electrode tab group and the second electrode tab group are disposed to face each other in the thickness direction of the electrode body,
The power storage device according to claim 1, wherein the first bending portion and the second bending portion are bent in a direction in which the first extension portion and the second extension portion approach each other.
前記第1電極タブ群と前記第2電極タブ群は、前記電極体の厚み方向において非対向となるように配置されており、
前記第1折曲部及び前記第2折曲部は、前記第1延在部と前記第2延在部が互いに近づく方向に折り曲げられている、請求項1又は2に記載の蓄電装置。
The first electrode tab group and the second electrode tab group are disposed so as not to face each other in the thickness direction of the electrode body,
The power storage device according to claim 1, wherein the first bending portion and the second bending portion are bent in a direction in which the first extension portion and the second extension portion approach each other.
前記第1電極タブ群と前記第2電極タブ群は、前記電極体の厚み方向において非対向となるように配置されており、
前記第1折曲部及び前記第2前記折曲部は、前記第1延在部と前記第2延在部が同じ方向に延在するように折り曲げられている、請求項1又は2に記載の蓄電装置。
The first electrode tab group and the second electrode tab group are disposed so as not to face each other in the thickness direction of the electrode body,
The said 1st bending part and the said 2nd said said bending part are bend | folded so that the said 1st extension part and the said 2nd extension part may extend in the same direction. Power storage device.
電極体の縁部から突出した複数の電極タブを、前記電極体の厚み方向に分割するようにそれぞれ重ねて第1電極タブ群及び第2電極タブ群を形成する第1工程と、
前記電極タブの重なり方向における前記第1電極タブ群の一端又は他端に第1集電部材を接続し、前記電極タブの重なり方向における前記第2電極タブ群の一端又は他端に第2集電部材を接続する第2工程と、
前記第1電極タブ群を前記電極体の厚み方向内側に折り曲げて、第1折曲部及び前記第1折曲部から前記電極体の厚み方向に延在する第1延在部を形成すると共に、前記第2電極タブ群を前記電極体の厚み方向内側に折り曲げて、第2折曲部及び前記第2折曲部から前記電極体の厚み方向に延在する第2延在部を形成する第3工程と、を有し、
前記3工程では、前記第1集電部材が前記第1延在部に位置するように前記第1電極タブ群を折り曲げ、前記第2集電部材が前記第2延在部に位置するように前記第2電極タブ群を折り曲げる、蓄電装置の製造方法。
A first step of forming a first electrode tab group and a second electrode tab group by respectively overlapping a plurality of electrode tabs projecting from an edge of the electrode body so as to be divided in a thickness direction of the electrode body;
A first current collecting member is connected to one end or the other end of the first electrode tab group in the overlapping direction of the electrode tabs, and a second current collecting member is connected to the one end or the other end of the second electrode tab group in the overlapping direction of the electrode tabs A second step of connecting the electrical members;
The first electrode tab group is bent inward in the thickness direction of the electrode body to form a first bent portion and a first extension portion extending from the first bent portion in the thickness direction of the electrode body. Forming a second extension portion extending in a thickness direction of the electrode body from a second bent portion and the second bent portion by bending the second electrode tab group inward in a thickness direction of the electrode body; And a third step,
In the three steps, the first electrode tab group is bent so that the first current collecting member is positioned at the first extending portion, and the second current collecting member is positioned at the second extending portion. The manufacturing method of the electrical storage apparatus which bend | folds the said 2nd electrode tab group.
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