JP2018092726A - Power storage device - Google Patents

Power storage device Download PDF

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JP2018092726A
JP2018092726A JP2016232937A JP2016232937A JP2018092726A JP 2018092726 A JP2018092726 A JP 2018092726A JP 2016232937 A JP2016232937 A JP 2016232937A JP 2016232937 A JP2016232937 A JP 2016232937A JP 2018092726 A JP2018092726 A JP 2018092726A
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case
short side
terminal
bottom wall
lid member
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幹也 栗田
Mikiya Kurita
幹也 栗田
泰有 秋山
Yasunari Akiyama
泰有 秋山
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Toyota Industries Corp
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Toyota Industries 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

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  • Gas Exhaust Devices For Batteries (AREA)
  • Connection Of Batteries Or Terminals (AREA)
  • Electric Double-Layer Capacitors Or The Like (AREA)
  • Sealing Battery Cases Or Jackets (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device capable of breaking a pressure relief valve when inner pressure of a case reaches a release pressure and lowering the inner pressure of the case.SOLUTION: A secondary battery 10 includes a case 11. The case 11 includes a rectangular bottom wall 14b, a pair of long side walls 14c that stand from the long side edges of a pair of the bottom wall 14b, a short side wall 14d that stands from one short side edge of the bottom wall 14b, and a top plate 14e that faces the bottom wall 14b and is connected to the pair of long side walls 14c and the short side wall 14d, and an opening 14a is provided on the other short side edge of the bottom wall 14b. A pressure relief valve 23 is located on the short side wall 14d of the case 11.SELECTED DRAWING: Figure 1

Description

本発明は、圧力開放弁を備える蓄電装置に関する。   The present invention relates to a power storage device including a pressure release valve.

二次電池やキャパシタのような蓄電装置は再充電が可能であり、繰り返し使用することができるため電源として広く利用されている。また、電気自動車やハイブリッド自動車のように走行モータの電源として二次電池を使用する場合は、大電流充電や大電流放電及び大容量化が要求されるため、複数個の二次電池を有する電池モジュールが使用されている。   Power storage devices such as secondary batteries and capacitors are widely used as power sources because they can be recharged and can be used repeatedly. In addition, when a secondary battery is used as a power source for a traveling motor, such as an electric vehicle or a hybrid vehicle, a battery having a plurality of secondary batteries is required because large current charging, large current discharging and large capacity are required. Module is in use.

二次電池としては、直方体状のケースと、ケース内に収容された直方体状の電極組立体と、を備えるものが知られている。電極組立体は、複数の正極電極及び複数の負極電極がセパレータを介して交互に積層された積層型、又は一枚の長尺帯状の正極電極及び一枚の長尺帯状の負極電極が、長尺帯状のセパレータを介して捲回された捲回型がある。   As a secondary battery, a battery including a rectangular parallelepiped case and a rectangular parallelepiped electrode assembly accommodated in the case is known. The electrode assembly is a stacked type in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked via separators, or a single long strip-shaped positive electrode and a single long strip-shaped negative electrode. There is a wound type wound through a strip-shaped separator.

また、二次電池のケースは、ケース部材と、ケース部材の開口部を閉塞する蓋部材と、を備える。ケース部材は、矩形板状の底壁と、底壁の一対の長側縁から立設された一対の長側壁と、底壁の一対の短側縁から立設された短側壁と、を有する。二次電池のケースとしては、薄型直方体状のものが多く採用されている。また、二次電池は、正極電極に接続された正極の端子構造と、負極電極に接続された負極の端子構造を備える(例えば特許文献1参照)。   The case of the secondary battery includes a case member and a lid member that closes the opening of the case member. The case member includes a rectangular plate-shaped bottom wall, a pair of long side walls standing from a pair of long side edges of the bottom wall, and a short side wall standing from a pair of short side edges of the bottom wall. . As the case of the secondary battery, a thin rectangular parallelepiped shape is often adopted. The secondary battery includes a positive terminal structure connected to the positive electrode and a negative terminal structure connected to the negative electrode (see, for example, Patent Document 1).

図7に示すように、特許文献1の電池は、正極の端子構造として正極端子部材80を備え、負極の端子構造として負極端子部材100を備える。なお、正極端子部材80と負極端子部材100は形状が同じであるため、正極端子部材80について説明し、負極端子部材100の説明は省略する。   As shown in FIG. 7, the battery of Patent Document 1 includes a positive terminal member 80 as a positive terminal structure and a negative terminal member 100 as a negative terminal structure. Since the positive electrode terminal member 80 and the negative electrode terminal member 100 have the same shape, the positive electrode terminal member 80 will be described and the description of the negative electrode terminal member 100 will be omitted.

正極端子部材80は、電極体92に接合された正極内部端子81を備える。正極内部端子81は、ほぼ全体が電池ケース90内に配設され、一部が電池ケース90の封口蓋91を貫通して電池ケース90の外部に突出している。また、正極内部端子81は、端子接続部材としての正極外部端子84、インシュレータ82、及びガスケット83を封口蓋91にかしめている。このかしめにより、正極内部端子81は正極外部端子84に導通している。   The positive electrode terminal member 80 includes a positive electrode internal terminal 81 joined to the electrode body 92. The entire positive electrode internal terminal 81 is disposed inside the battery case 90, and a part of the positive electrode internal terminal 81 penetrates the sealing lid 91 of the battery case 90 and protrudes outside the battery case 90. In addition, the positive electrode internal terminal 81 has a positive electrode external terminal 84, an insulator 82, and a gasket 83 as terminal connecting members caulked to the sealing lid 91. By this caulking, the positive electrode internal terminal 81 is electrically connected to the positive electrode external terminal 84.

正極外部端子84はクランク形状であり、封口蓋91の外側に配置されている。正極外部端子84は、正極内部端子81のかしめによって固定される固定部84aと、外部接続端子としての正極締結ボルト85と接続する接続部84bと、固定部84aと接続部84bとを連結する連結部84cとを有する。正極締結ボルト85は、複数の電池をモジュール化する場合に、バスバーを締結するための部材である。   The positive electrode external terminal 84 has a crank shape and is disposed outside the sealing lid 91. The positive external terminal 84 is a connection that connects the fixed portion 84a fixed by caulking of the positive internal terminal 81, the connection portion 84b connected to the positive fastening bolt 85 as an external connection terminal, and the fixed portion 84a and the connection portion 84b. Part 84c. The positive electrode fastening bolt 85 is a member for fastening the bus bar when a plurality of batteries are modularized.

ガスケット83は、電気的絶縁性を有し、正極内部端子81と封口蓋91との間に介在し、両者を絶縁する。インシュレータ82は、電気的絶縁性を有し、正極外部端子84と封口蓋91との間に介在し、両者を絶縁する。   The gasket 83 has electrical insulation and is interposed between the positive electrode internal terminal 81 and the sealing lid 91 to insulate both. The insulator 82 has electrical insulation and is interposed between the positive external terminal 84 and the sealing lid 91 to insulate both.

また、特許文献1の電池は、封口蓋91の長手方向の中央部に圧力開放弁としての安全弁93を備える。安全弁93は、封口蓋91と一体的に形成されている。安全弁93は、電池ケース90の内圧が開放圧に達した際に開裂し、電池ケース90の内部のガスを外部に放出して電池ケース90の内圧を下げる。   Further, the battery of Patent Document 1 includes a safety valve 93 as a pressure release valve at the center in the longitudinal direction of the sealing lid 91. The safety valve 93 is formed integrally with the sealing lid 91. The safety valve 93 is cleaved when the internal pressure of the battery case 90 reaches the open pressure, and releases the gas inside the battery case 90 to the outside to lower the internal pressure of the battery case 90.

ところで、特許文献1の電池において、正極端子部材80及び負極端子部材100の一部は、電池ケース90内に配置されている。電池ケース90内において、電極体92の端面92aと、この端面92aに対向した封口蓋91の内面91aとの間には、正極端子部材80及び負極端子部材100の設置スペースを確保する必要がある。電池ケース90内の設置スペースは電池容量に寄与しないデッドスペースとなる。よって、設置スペースを減らすことで、電池ケース90内で電極体92を収容できる容積を増大させ、電池のエネルギ密度を大きくすることが可能になる。   By the way, in the battery of Patent Document 1, a part of the positive electrode terminal member 80 and the negative electrode terminal member 100 is disposed in the battery case 90. In the battery case 90, it is necessary to secure an installation space for the positive electrode terminal member 80 and the negative electrode terminal member 100 between the end surface 92a of the electrode body 92 and the inner surface 91a of the sealing lid 91 facing the end surface 92a. . The installation space in the battery case 90 is a dead space that does not contribute to the battery capacity. Therefore, by reducing the installation space, the volume that can accommodate the electrode body 92 in the battery case 90 can be increased, and the energy density of the battery can be increased.

その一方で、一般的に二次電池は、車両の床下に配置される場合が多く、二次電池の配置空間には上下方向(高さ)に制限がある場合がほとんどである。そこで、特許文献1の電池の上下方向の寸法(高さ)は変えず、電池ケース90内の設置スペースを減らすため、封口蓋91を、電池ケース90において面積の小さい壁部のある位置(図7では、左右の側壁)に配置することが考えられる。この場合は、封口蓋91を電池ケース90の側方に配置し、電気の授受を電池ケース90の側方から行う形態となる。   On the other hand, in general, the secondary battery is often arranged under the floor of the vehicle, and the arrangement space of the secondary battery is often limited in the vertical direction (height). Therefore, in order to reduce the installation space in the battery case 90 without changing the vertical dimension (height) of the battery of Patent Document 1, the position of the sealing lid 91 in the battery case 90 with a small wall portion (see FIG. 7, it can be considered to be arranged on the left and right side walls. In this case, the sealing lid 91 is disposed on the side of the battery case 90, and electricity is transferred from the side of the battery case 90.

特開2014−154291号公報JP 2014-154291 A

ところで、電池ケース90の内圧が開放圧に達した際に、安全弁93が適切に作動して電池ケース90の内部のガスを外部に放出して電池ケース90の内圧を下げるには、安全弁93は、発生ガス量に対して一定の開口面積を必要とする。しかし、封口蓋91を電池ケース90の側方に配置し、その封口蓋91に正極端子部材80及び負極端子部材100を配置すると、安全弁93の開口面積を十分に確保できなくなる。すると、安全弁93が適切に作動せず、安全弁93の開口面積を十分に確保できない結果、電池ケース90の内圧が開放圧以上に上がってしまい、電池ケース90及び封口蓋91が損傷を受ける虞がある。   By the way, when the internal pressure of the battery case 90 reaches the open pressure, the safety valve 93 is appropriately operated to release the gas inside the battery case 90 to the outside to lower the internal pressure of the battery case 90. A certain opening area is required for the amount of generated gas. However, if the sealing lid 91 is arranged on the side of the battery case 90 and the positive electrode terminal member 80 and the negative electrode terminal member 100 are arranged on the sealing lid 91, the opening area of the safety valve 93 cannot be secured sufficiently. As a result, the safety valve 93 does not operate properly, and the opening area of the safety valve 93 cannot be secured sufficiently. As a result, the internal pressure of the battery case 90 rises above the open pressure, and the battery case 90 and the sealing lid 91 may be damaged. is there.

本発明の目的は、ケースの内圧が開放圧に達した際に圧力開放弁を開裂させてケースの内圧を下げることができる蓄電装置を提供することにある。   An object of the present invention is to provide a power storage device that can open a pressure release valve to lower the internal pressure of the case when the internal pressure of the case reaches the open pressure.

上記問題点を解決するための蓄電装置は、異なる極性の電極が互いに絶縁されて積層された電極組立体と、前記電極組立体を収容したケース部材、及び該ケース部材の開口部を閉塞する矩形状の蓋部材を有するケースと、前記蓋部材の内面と、該内面に対向した前記電極組立体の端面との間の設置スペースに配置され、かつ前記電極組立体と電気的に接続された各極性の導電部材と、前記設置スペースで前記各極性の導電部材と電気的にそれぞれ接続され、かつ前記蓋部材を貫通して前記ケースの外部に突出した各極性の引出端子と、前記ケースの外部に配置され、かつ前記各極性の引出端子とそれぞれ電気的に接続された各極性の端子接続部材と、前記ケース内の圧力が開放圧に達した場合に開裂し、前記ケース内の圧力を前記ケースの外部に開放させる圧力開放弁と、を備え、前記ケース部材は、矩形状の底壁と、該底壁の一対の長側縁から立設された一対の長側壁と、前記底壁の一方の短側縁から立設された短側壁と、前記底壁と対向し、一対の前記長側壁と前記短側壁とに接続された天板と、を有し、前記底壁の他方の短側縁側に前記開口部を備え、前記底壁と、前記一対の長側壁と、前記短側壁と、前記天板と、前記蓋部材とは、それぞれ前記ケースの壁部を形成し、前記圧力開放弁は、前記壁部のうちの前記短側壁に位置することを要旨とする。   A power storage device for solving the above problems includes an electrode assembly in which electrodes of different polarities are insulated from each other, a case member that accommodates the electrode assembly, and a rectangular that closes an opening of the case member. Each of which is disposed in an installation space between a case having a lid member having a shape, an inner surface of the lid member, and an end surface of the electrode assembly facing the inner surface, and electrically connected to the electrode assembly. A conductive member of polarity, a lead terminal of each polarity electrically connected to the conductive member of each polarity in the installation space and penetrating through the lid member and projecting to the outside of the case; and the outside of the case Each polarity terminal connecting member electrically connected to each of the lead terminals of each polarity, and when the pressure in the case reaches the release pressure, the pressure in the case is Outside the case The case member includes a rectangular bottom wall, a pair of long side walls erected from a pair of long side edges of the bottom wall, and one short side of the bottom wall. A short side wall erected from a side edge, and a top plate facing the bottom wall and connected to the pair of the long side wall and the short side wall, on the other short side edge side of the bottom wall The opening is provided, the bottom wall, the pair of long side walls, the short side wall, the top plate, and the lid member each form a wall portion of the case, and the pressure release valve is The gist is to be located on the short side wall of the wall portion.

これによれば、異なる蓄電装置との電気的な接続のために、端子接続部材にはバスバーが接続されるが、端子接続部材とバスバーの接続面での電気的な抵抗を低くするには接続面は可能な限り大きい方が好ましい。よって、蓋部材の外側に配置される端子接続部材は、蓋部材の外面を広く覆う状態となり、しかも、各極性毎にそれぞれ配置される。このような蓄電装置において、圧力開放弁を蓋部材ではなく短側壁に位置させた。短側壁には、端子接続部材は配置されていない。このため、圧力開放弁として必要な開口面積を確保でき、開放圧に達すると圧力開放弁が適切に作動して開裂し、圧力開放弁の開口面積を十分に確保できる。その結果、ケースの内圧を好適に下げ、ケースが損傷を受けることを抑制できる。   According to this, the bus bar is connected to the terminal connection member for electrical connection with different power storage devices, but connection is required to reduce the electrical resistance at the connection surface between the terminal connection member and the bus bar. The surface is preferably as large as possible. Therefore, the terminal connection member arranged outside the lid member covers the outer surface of the lid member widely, and is arranged for each polarity. In such a power storage device, the pressure release valve is positioned not on the lid member but on the short side wall. No terminal connection member is disposed on the short side wall. For this reason, an opening area required as a pressure release valve can be secured, and when the release pressure is reached, the pressure release valve is appropriately operated and cleaved, and a sufficient opening area of the pressure release valve can be secured. As a result, the internal pressure of the case can be suitably lowered and the case can be prevented from being damaged.

蓄電装置について、前記ケース部材は、絞り加工によって形成されていてもよい。
これによれば、ケース部材が絞り加工で形成されると、開口部に対向する短側壁の厚みが、その他の長側壁、底壁、及び天板と比較して厚くなる。このため、短側壁に形成された圧力開放弁の厚みを確保でき、圧力開放弁の厚み調整に幅を持たせることができる。また、圧力開放弁の厚みを確保して誤作動しにくいものとすることができる。
Regarding the power storage device, the case member may be formed by drawing.
According to this, when the case member is formed by drawing, the thickness of the short side wall facing the opening becomes thicker than the other long side walls, the bottom wall, and the top plate. For this reason, the thickness of the pressure release valve formed in the short side wall can be ensured, and the thickness adjustment of the pressure release valve can be widened. In addition, the thickness of the pressure release valve can be secured to prevent malfunction.

蓄電装置について、前記圧力開放弁は、該圧力開放弁の周縁の一部を構成する弧部と、互いに交差する2本の直線溝を含む交差溝と、該交差溝の端部に繋がるとともに前記弧部に沿う複数の弧状溝とを有し、前記交差溝に沿って延長し、かつ前記圧力開放弁の周縁と交差する2本の仮想直線を想定したとき、前記各仮想直線と前記圧力開放弁の周縁とによって囲まれた第2の領域と、前記各仮想直線と前記弧部とによって囲まれた第1の領域とが想定され、前記第1の領域の前記弧部に接する部分が前記第2の領域の前記弧部に接する部分よりも多くなるように前記第1及び第2の領域が構成され、前記第1の領域の面積が、前記第2の領域の面積よりも大きくてもよい。   Regarding the power storage device, the pressure release valve is connected to an arc portion that forms a part of the periphery of the pressure release valve, an intersecting groove that includes two linear grooves that intersect with each other, and an end of the intersecting groove and A plurality of arc-shaped grooves along the arc portion, extending along the intersecting groove, and assuming two virtual straight lines intersecting the peripheral edge of the pressure relief valve, the virtual lines and the pressure relief A second region surrounded by the peripheral edge of the valve and a first region surrounded by each imaginary straight line and the arc portion are assumed, and a portion in contact with the arc portion of the first region is the The first and second regions are configured to be larger than the portion of the second region that contacts the arc portion, and the area of the first region is larger than the area of the second region. Good.

これによれば、弧部に沿う弧状溝を有する場合に、弧部に接する部分が多い第1の領域の面積を弧部に接する部分が少ない第2の領域の面積よりも大きい面積としている。このため、第1の領域は、ケース内の圧力を受圧する面積が大きくなり、弧状溝の開裂が促進される。したがって、圧力開放弁の開口面積を大きくすることができ、ケース内の圧力を迅速に開放させることができる。   According to this, in the case of having an arc-shaped groove along the arc portion, the area of the first region having a large portion in contact with the arc portion is set to be larger than the area of the second region having a small portion in contact with the arc portion. For this reason, the area which receives the pressure in a case becomes large in the 1st field, and cleavage of an arc-like groove is promoted. Therefore, the opening area of the pressure release valve can be increased, and the pressure in the case can be quickly released.

前記蓄電装置は二次電池である。   The power storage device is a secondary battery.

本発明によれば、ケースの内圧が開放圧に達した際に圧力開放弁を開裂させてケースの内圧を下げることができる。   According to the present invention, when the internal pressure of the case reaches the open pressure, the internal pressure of the case can be lowered by opening the pressure release valve.

実施形態の二次電池を示す分解斜視図。The disassembled perspective view which shows the secondary battery of embodiment. 実施形態の二次電池の外観を示す斜視図。The perspective view which shows the external appearance of the secondary battery of embodiment. 負極端子構造を示す部分断面図。The fragmentary sectional view which shows a negative electrode terminal structure. 圧力開放弁の配置された短側壁側から示す部分斜視図。The partial perspective view shown from the short side wall side where the pressure release valve is arrange | positioned. 圧力開放弁を示す平面図。The top view which shows a pressure release valve. (a)は実施形態の二次電池を示す正面図、(b)は比較例の二次電池を示す正面図。(A) is a front view which shows the secondary battery of embodiment, (b) is a front view which shows the secondary battery of a comparative example. 背景技術を示す図。The figure which shows background art.

以下、蓄電装置を二次電池に具体化した一実施形態を図1〜図6にしたがって説明する。
図1又は図2に示すように、蓄電装置としての二次電池10はケース11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る。二次電池10は、ケース11内に収容された電極組立体12及び電解液(図示せず)を備える。ケース11は、四角箱状のケース部材14と、このケース部材14の開口部14aを閉塞する矩形平板状の蓋部材15とを有している。
Hereinafter, an embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIGS.
As shown in FIG. 1 or FIG. 2, the secondary battery 10 as the power storage device includes a case 11. The secondary battery 10 of the present embodiment is a lithium ion battery. The secondary battery 10 includes an electrode assembly 12 accommodated in a case 11 and an electrolytic solution (not shown). The case 11 includes a rectangular box-shaped case member 14 and a rectangular flat plate-shaped lid member 15 that closes the opening 14 a of the case member 14.

ケース部材14は、平らな金属板を図示しないプレス機でプレスする絞り加工、特に深絞り加工によって形成されており、継ぎ目のない有底筒状である。ケース部材14は、一枚の矩形板状の底壁14bと、底壁14bの一対の長側縁から立設された一対の長側壁14cと、底壁14bの一方の短側縁から立設された短側壁14dと、一対の長側壁14cと短側壁14dとに接続された天板14eと、を有する。   The case member 14 is formed by a drawing process for pressing a flat metal plate with a press machine (not shown), particularly a deep drawing process, and has a seamless bottomed cylindrical shape. The case member 14 is erected from one rectangular plate-shaped bottom wall 14b, a pair of long side walls 14c erected from a pair of long side edges of the bottom wall 14b, and one short side edge of the bottom wall 14b. A short side wall 14d, and a pair of long side walls 14c and a top plate 14e connected to the short side wall 14d.

深絞り加工の際、金属板において、プレス機でプレスされた部分に短側壁14dが形成され、プレスに伴い引き延ばされた部分に底壁14b、一対の長側壁14c、及び天板14eが形成される。このため、ケース部材14の開口部14aは、短側壁14dと対向する位置に形成される。また、短側壁14dの厚みは、引き延ばしによって形成された底壁14b、一対の長側壁14c、及び天板14eの厚みよりも厚い。   At the time of deep drawing, a short side wall 14d is formed in a portion of the metal plate that is pressed by a press, and a bottom wall 14b, a pair of long side walls 14c, and a top plate 14e are formed in a portion that is extended with the press. It is formed. For this reason, the opening part 14a of the case member 14 is formed in the position facing 14 d of short side walls. Further, the thickness of the short side wall 14d is larger than the thickness of the bottom wall 14b, the pair of long side walls 14c, and the top plate 14e formed by stretching.

なお、底壁14bと天板14eとは上下方向に対向する。よって、本実施形態において、底壁14bと天板14eとの対向方向は上下方向である。
ケース部材14の開口部14aは、底壁14bの他方の短側縁側に位置している。開口部14aは、ケース部材14の側方に開口しており、短側壁14dと対向した位置にある。ケース部材14の開口部14aは、蓋部材15によって閉塞されている。ケース11は、六つの壁部である底壁14b、一対の長側壁14c、短側壁14d、天板14e及び蓋部材15によって形成されている。
The bottom wall 14b and the top plate 14e face each other in the vertical direction. Therefore, in this embodiment, the opposing direction of the bottom wall 14b and the top plate 14e is the up-down direction.
The opening 14a of the case member 14 is located on the other short side edge side of the bottom wall 14b. The opening 14a opens to the side of the case member 14 and is in a position facing the short side wall 14d. The opening 14 a of the case member 14 is closed by the lid member 15. The case 11 is formed by a bottom wall 14b, which is six walls, a pair of long side walls 14c, a short side wall 14d, a top plate 14e, and a lid member 15.

底壁14b及び天板14eの長手方向への寸法は、短側壁14dの長手方向への寸法(高さ)より長い。また、底壁14b及び天板14eの短手方向への寸法は、短側壁14dの短手方向への寸法と同じである。よって、短側壁14dは、底壁14b及び天板14eより面積が小さく、ケース11の壁部のうち最も面積が小さい。   The dimension in the longitudinal direction of the bottom wall 14b and the top plate 14e is longer than the dimension (height) in the longitudinal direction of the short side wall 14d. Further, the dimension in the short direction of the bottom wall 14b and the top plate 14e is the same as the dimension in the short direction of the short side wall 14d. Therefore, the short side wall 14 d has a smaller area than the bottom wall 14 b and the top plate 14 e, and has the smallest area among the wall portions of the case 11.

蓋部材15は、ケース部材14の壁部のうち最も小さい面積の短側壁14dと対向した位置にある。したがって、蓋部材15は、短側壁14dと同様にケース11の壁部のうち最も面積の小さい壁部を構成している。   The lid member 15 is located at a position facing the short side wall 14 d having the smallest area among the wall portions of the case member 14. Therefore, the lid member 15 constitutes the wall portion having the smallest area among the wall portions of the case 11 like the short side wall 14d.

図1又は図4に示すように、二次電池10は、短側壁14dに位置する圧力開放弁23を備える。圧力開放弁23は、短側壁14dの長手方向(上下方向)及び短手方向(横方向)における中央部に配置されている。圧力開放弁23は、ケース11内にガスが発生した際、ケース11内の圧力が上昇し過ぎないように、ケース11内の圧力が所定の圧力である開放圧に達した場合に開裂し、ケース11の内外を連通させる。   As shown in FIG. 1 or FIG. 4, the secondary battery 10 includes a pressure release valve 23 located on the short side wall 14d. The pressure release valve 23 is arranged at the center in the longitudinal direction (vertical direction) and the lateral direction (lateral direction) of the short side wall 14d. The pressure release valve 23 is cleaved when the pressure in the case 11 reaches an opening pressure that is a predetermined pressure so that the pressure in the case 11 does not increase excessively when gas is generated in the case 11. The inside and outside of the case 11 are communicated.

圧力開放弁23は、ケース11の内圧が開放圧に達した際、適切に作動して一定の開口面積が確保できるように設計されている。圧力開放弁23の「一定の開口面積」とは、開裂した圧力開放弁23からケース11の内部のガスをケース11の外に放出してケース11の内圧を下げ、ケース11の内圧が開放圧以上になることを抑制できる開口面積である。また、圧力開放弁23の「一定の開口面積」とは、ケース11内での発生ガス量に対して予め決められた開口面積でもある。圧力開放弁23の開放圧は、ケース11自体やケース部材14と蓋部材15の接合部に亀裂や損傷を受けるなどが生じ得る前に開裂し得る圧力に設定されている。   The pressure release valve 23 is designed so that when the internal pressure of the case 11 reaches the release pressure, the pressure release valve 23 operates properly to ensure a certain opening area. The “constant opening area” of the pressure release valve 23 means that the gas inside the case 11 is released from the cleaved pressure release valve 23 to the outside of the case 11 to lower the internal pressure of the case 11, and the internal pressure of the case 11 It is an opening area which can suppress becoming above. Further, the “constant opening area” of the pressure release valve 23 is also an opening area determined in advance for the amount of gas generated in the case 11. The release pressure of the pressure release valve 23 is set to a pressure at which the case 11 itself or the joint between the case member 14 and the lid member 15 can be cracked before being cracked or damaged.

圧力開放弁23は、短側壁14dの板厚よりも薄い薄板状の弁体24を有する。弁体24は、短側壁14dの外面に凹設された凹部22の底に位置しており、短側壁14dと一体的に成形されている。   The pressure release valve 23 has a thin plate-like valve body 24 that is thinner than the plate thickness of the short side wall 14d. The valve body 24 is located at the bottom of the recess 22 provided in the outer surface of the short side wall 14d, and is formed integrally with the short side wall 14d.

図5に示すように、圧力開放弁23は、平行な2つの直線部26,27を弧部28,29で繋いだトラック形状の周縁を有する。なお、弁体24は、圧力開放弁23の周縁に繋がっており、圧力開放弁23と同様にトラック形状である。   As shown in FIG. 5, the pressure release valve 23 has a track-shaped periphery in which two parallel straight portions 26 and 27 are connected by arc portions 28 and 29. The valve body 24 is connected to the periphery of the pressure release valve 23 and has a track shape like the pressure release valve 23.

弧部28は、一方の端部が直線部26の一方の端部に繋がっているとともに、他方の端部が直線部27の一方の端部に繋がっている。弧部29は、一方の端部が直線部26の他方の端部に繋がっているとともに、他方の端部が直線部27の他方の端部に繋がっている。直線部26,27の一方の端部は、その全体を弧状とした弧部28で繋がっているとともに、直線部26,27の他方の端部は、その全体を弧状とした弧部29で繋がっている。圧力開放弁23において、直線部26,27の端部と弧部28,29の端部とが繋がる部位が、直線部26,27と弧部28,29の境界P1,P2,P3,P4となる。   The arc portion 28 has one end connected to one end of the straight portion 26 and the other end connected to one end of the straight portion 27. The arc portion 29 has one end connected to the other end of the straight portion 26 and the other end connected to the other end of the straight portion 27. One end of the straight portions 26 and 27 is connected by an arc portion 28 having an arc shape as a whole, and the other end of the straight portions 26 and 27 is connected by an arc portion 29 having an arc shape as a whole. ing. In the pressure release valve 23, the portion where the ends of the straight portions 26 and 27 and the ends of the arc portions 28 and 29 are connected is the boundary P1, P2, P3, P4 between the straight portions 26 and 27 and the arc portions 28 and 29. Become.

弁体24は、表面24aに複数の溝を有する。複数の溝は、隣り合う境界P1〜P4の位置を図5において二点鎖線で示す直線で結んだ四角形状の領域内に位置する交差溝30と、弧部28,29に沿う複数の弧状溝31,32と、からなる。交差溝30と弧状溝31,32は、何れもV字形溝である。   The valve body 24 has a plurality of grooves on the surface 24a. The plurality of grooves include a crossing groove 30 located in a rectangular region in which the positions of adjacent boundaries P1 to P4 are connected by a straight line indicated by a two-dot chain line in FIG. 5, and a plurality of arcuate grooves along the arc portions 28 and 29 31 and 32. The intersecting groove 30 and the arc-shaped grooves 31 and 32 are both V-shaped grooves.

交差溝30は、2本の直線溝30a,30bからなる。直線溝30aは、直線部26,27と弧部28,29の境界P1〜P4のうち、境界P1,P4を結ぶ仮想直線Y1上に位置している。一方、直線溝30bは、直線部26,27と弧部28,29の境界P1〜P4のうち、境界P2,P3を結ぶ仮想直線Y2上に位置している。仮想直線Y1,Y2は、交差溝30に沿って延長され、かつ圧力開放弁23の周縁に交差する。また、仮想直線Y1,Y2は、直線部26,27と弧部28,29の境界P1〜P4に位置する2本の直線である。そして、2本の直線溝30a,30bは、弁体24の中央で交差している。なお、境界P1,P4は仮想直線Y1と圧力開放弁23の周縁との交差点でもあり、境界P2,P3は仮想直線Y2と圧力開放弁23の周縁との交差点でもある。   The intersecting groove 30 is composed of two straight grooves 30a and 30b. The straight groove 30a is located on a virtual straight line Y1 connecting the boundaries P1 and P4 among the boundaries P1 to P4 between the straight portions 26 and 27 and the arc portions 28 and 29. On the other hand, the straight groove 30b is located on the virtual straight line Y2 connecting the boundaries P2 and P3 among the boundaries P1 to P4 between the straight portions 26 and 27 and the arc portions 28 and 29. The virtual straight lines Y1 and Y2 extend along the intersecting groove 30 and intersect the peripheral edge of the pressure release valve 23. The virtual straight lines Y1 and Y2 are two straight lines located at the boundaries P1 to P4 between the straight portions 26 and 27 and the arc portions 28 and 29. The two straight grooves 30 a and 30 b intersect at the center of the valve body 24. The boundaries P1 and P4 are also intersections between the virtual straight line Y1 and the periphery of the pressure release valve 23, and the boundaries P2 and P3 are also intersections between the virtual straight line Y2 and the periphery of the pressure release valve 23.

また、弁体24は、弧部28に沿う2本の弧状溝31を表面24aに有するとともに、弧部29に沿う2本の弧状溝32を表面24aに有する。2本の弧状溝31のうち、一方の弧状溝31は、直線溝30aにおいて境界P1側に位置する一方の端部に繋がっており、弧部28に沿って弧状に延在しているとともに、直線部26に沿って直線状に延在している。   Further, the valve body 24 has two arc-shaped grooves 31 along the arc portion 28 on the surface 24a, and has two arc-shaped grooves 32 along the arc portion 29 on the surface 24a. Of the two arc-shaped grooves 31, one arc-shaped groove 31 is connected to one end located on the boundary P <b> 1 side in the linear groove 30 a, and extends in an arc shape along the arc portion 28. It extends linearly along the straight portion 26.

また、2本の弧状溝32のうち、一方の弧状溝32は、直線溝30bにおいて境界P2側に位置する一方の端部に繋がっており、弧部29に沿って弧状に延在しているとともに、直線部26に沿って直線状に延在している。なお、2本の弧状溝31のうち、他方の弧状溝31は、直線溝30bにおいて境界P3側に位置する他方の端部に繋がっており、弧部28に沿って弧状に延在しているとともに、直線部27に沿って直線状に延在している。   Of the two arc-shaped grooves 32, one arc-shaped groove 32 is connected to one end located on the boundary P <b> 2 side in the linear groove 30 b, and extends in an arc shape along the arc portion 29. At the same time, it extends linearly along the straight portion 26. Of the two arc-shaped grooves 31, the other arc-shaped groove 31 is connected to the other end located on the boundary P3 side in the linear groove 30b, and extends in an arc shape along the arc portion 28. At the same time, it extends linearly along the straight portion 27.

また、2本の弧状溝32のうち、他方の弧状溝32は、直線溝30aにおいて境界P4側に位置する他方の端部に繋がっており、弧部29に沿って弧状に延在しているとともに、直線部27に沿って直線状に延在している。各弧状溝31,32は、弧部28,29の一部に沿って設けられている。弁体24は、直線溝30aに繋がる各1本の弧状溝31,32を有するとともに、直線溝30bに繋がる各1本の弧状溝31,32を有する。   Of the two arc-shaped grooves 32, the other arc-shaped groove 32 is connected to the other end located on the boundary P4 side in the linear groove 30a, and extends in an arc shape along the arc portion 29. At the same time, it extends linearly along the straight portion 27. Each arcuate groove 31, 32 is provided along a part of the arc portions 28, 29. The valve body 24 includes one arcuate groove 31 and 32 connected to the linear groove 30a and one arcuate groove 31 and 32 connected to the linear groove 30b.

弁体24の表面24aには、交差溝30に沿う仮想直線Y1,Y2を想定したとき、仮想直線Y1,Y2と圧力開放弁23の周縁によって囲まれる複数の領域S1,S2,S3,S4が想定される。領域S1は、直線溝30a,30bの交差点Xと境界P1との間に位置する仮想直線Y1の部分と、交差点Xと境界P2との間に位置する仮想直線Y2の部分と、直線部26と、によって区画される領域である。また、領域S2は、交差点Xと境界P3との間に位置する仮想直線Y2の部分と、交差点Xと境界P4との間に位置する仮想直線Y1の部分と、直線部27と、によって区画される領域である。領域S1と領域S2は、交差点Xを対称の中心として点対称である。   On the surface 24a of the valve body 24, when assuming virtual straight lines Y1 and Y2 along the intersecting grooves 30, a plurality of regions S1, S2, S3 and S4 surrounded by the virtual straight lines Y1 and Y2 and the periphery of the pressure release valve 23 are provided. is assumed. The region S1 includes a portion of the virtual straight line Y1 located between the intersection X and the boundary P1 of the straight grooves 30a and 30b, a portion of the virtual straight line Y2 located between the intersection X and the boundary P2, and a straight portion 26. , Is an area partitioned by. Further, the region S2 is partitioned by a portion of the virtual straight line Y2 located between the intersection X and the boundary P3, a portion of the virtual straight line Y1 located between the intersection X and the boundary P4, and the straight line portion 27. Area. The region S1 and the region S2 are point symmetric with the intersection X as the center of symmetry.

領域S3は、交差点Xと境界P1との間に位置する仮想直線Y1の部分と、交差点Xと境界P3との間に位置する仮想直線Y2の部分と、弧部28と、によって区画される領域である。また、領域S4は、交差点Xと境界P2との間に位置する仮想直線Y2の部分と、交差点Xと境界P4との間に位置する仮想直線Y1の部分と、弧部29と、によって区画される領域である。領域S3と領域S4は、交差点Xを対称の中心として点対称である。   The region S3 is a region defined by the portion of the virtual straight line Y1 located between the intersection X and the boundary P1, the portion of the virtual straight line Y2 located between the intersection X and the boundary P3, and the arc portion 28. It is. The region S4 is partitioned by a virtual straight line Y2 portion located between the intersection X and the boundary P2, a virtual straight line Y1 portion located between the intersection X and the boundary P4, and the arc portion 29. Area. The region S3 and the region S4 are point symmetric with the intersection X as the center of symmetry.

領域S1,S2は、仮想直線Y1,Y2が図5において二点鎖線で示す直線で結んだ四角形状の領域内に位置することで、直線部26,27のみに接する領域となる。一方、この実施形態において、領域S3,S4は、弧部28,29を含む領域であり、弧部28,29の全体に接する領域となる。そして、この実施形態において領域S1,S2は弧部28,29に接する部分が少ない第2の領域となり、領域S3,S4は弧部28,29に接する部分が多い第1の領域となる。そして、弁体24の表面24aに有する4つの領域S1〜S4の面積は、弧部28,29に接する部分が多い領域S3,S4の方が、弧部28,29に接する部分が少ない領域S1,S2に比較して大きい。   The regions S1 and S2 are regions that are in contact with only the straight portions 26 and 27 because the virtual straight lines Y1 and Y2 are located within a rectangular region connected by a straight line indicated by a two-dot chain line in FIG. On the other hand, in this embodiment, the regions S3 and S4 are regions including the arc portions 28 and 29 and are in contact with the entire arc portions 28 and 29. In this embodiment, the regions S1 and S2 are the second regions with few portions in contact with the arc portions 28 and 29, and the regions S3 and S4 are the first regions with many portions in contact with the arc portions 28 and 29. The area of the four regions S1 to S4 on the surface 24a of the valve body 24 is such that the regions S3 and S4 having more portions in contact with the arc portions 28 and 29 have less portions in contact with the arc portions 28 and 29. , Larger than S2.

図1又は図3に示すように、電極組立体12は、シート状の複数の正極電極21とシート状の複数の負極電極19とを備える。正極電極21と負極電極19とは異なる極性の電極である。詳細に図示しないが、正極電極21は、正極金属箔(本実施形態ではアルミニウム箔)と、その正極金属箔の両面に存在する正極活物質層とを有する。負極電極19は、負極金属箔(本実施形態では銅箔)と、その負極金属箔の両面に存在する負極活物質層とを有する。そして、電極組立体12は、複数の正極電極21と複数の負極電極19の間にこれらを絶縁する図示しないセパレータを介在させて層状とした積層型である。   As shown in FIG. 1 or FIG. 3, the electrode assembly 12 includes a plurality of sheet-like positive electrodes 21 and a plurality of sheet-like negative electrodes 19. The positive electrode 21 and the negative electrode 19 are electrodes having different polarities. Although not shown in detail, the positive electrode 21 has a positive metal foil (in this embodiment, an aluminum foil) and a positive electrode active material layer present on both surfaces of the positive metal foil. The negative electrode 19 has a negative electrode metal foil (copper foil in this embodiment) and a negative electrode active material layer present on both sides of the negative electrode metal foil. The electrode assembly 12 is a laminated type in which a plurality of positive electrodes 21 and a plurality of negative electrodes 19 are interposed between separators (not shown) to insulate them.

正極電極21は、正極電極21の一辺の一部から突出した形状のタブ21aを有する。負極電極19は、負極電極19の一辺の一部から突出した形状のタブ19aを有する。複数の正極のタブ21a、及び複数の負極のタブ19aは、正極電極21及び負極電極19が積層された状態で、正極のタブ21aと負極のタブ19aとが重ならない位置にそれぞれ設けられている。電極組立体12は、タブ19a,21aの突出したタブ側端面12aを有する。   The positive electrode 21 has a tab 21 a having a shape protruding from a part of one side of the positive electrode 21. The negative electrode 19 has a tab 19 a having a shape protruding from a part of one side of the negative electrode 19. The plurality of positive electrode tabs 21a and the plurality of negative electrode tabs 19a are provided at positions where the positive electrode tab 21a and the negative electrode tab 19a do not overlap with each other in a state where the positive electrode 21 and the negative electrode 19 are stacked. . The electrode assembly 12 has tab side end surfaces 12a from which the tabs 19a and 21a protrude.

ここで、蓋部材15において、ケース11の外側に臨む面を外面15c、ケース11の内側に臨む面を内面15dとすると、タブ側端面12aは、蓋部材15の内面15dに対向する電極組立体12の端面である。なお、蓋部材15において、外面15cと内面15dを最短距離で結ぶ方向を厚み方向とする。   Here, in the lid member 15, when the surface facing the outer side of the case 11 is an outer surface 15 c and the surface facing the inner side of the case 11 is an inner surface 15 d, the tab side end surface 12 a is an electrode assembly facing the inner surface 15 d of the lid member 15. 12 end faces. In the lid member 15, the direction connecting the outer surface 15c and the inner surface 15d with the shortest distance is the thickness direction.

二次電池10は、タブ側端面12aから蓋部材15に向けて突出した正極のタブ群36を有する。正極のタブ群36は、全ての正極のタブ21aを電極組立体12における積層方向の一端側に寄せ集め、積層して構成されている。二次電池10は、タブ側端面12aから蓋部材15に向けて突出した負極のタブ群36を有する。負極のタブ群36は、全ての負極のタブ19aを電極組立体12における積層方向の一端側に寄せ集め、積層して構成されている。   The secondary battery 10 includes a positive electrode tab group 36 that protrudes from the tab-side end surface 12 a toward the lid member 15. The positive electrode tab group 36 is configured by collecting and stacking all the positive electrode tabs 21 a on one end side in the stacking direction of the electrode assembly 12. The secondary battery 10 includes a negative electrode tab group 36 protruding toward the lid member 15 from the tab-side end surface 12a. The negative electrode tab group 36 is configured by gathering all negative electrode tabs 19 a together on one end side in the stacking direction of the electrode assembly 12 and stacking them.

正極のタブ群36には正極の導電部材51が接合されている。正極の導電部材51の長手方向一端側には正極のタブ群36が接合されている。正極の導電部材51の長手方向他端側には正極の引出端子60が接合されている。   A positive electrode conductive member 51 is joined to the positive electrode tab group 36. A positive electrode tab group 36 is joined to one end in the longitudinal direction of the positive electrode conductive member 51. A positive lead terminal 60 is joined to the other longitudinal end of the positive electrode conductive member 51.

負極のタブ群36には負極の導電部材51が接合されている。負極の導電部材51の長手方向一端側には負極のタブ群36が接合されている。負極の導電部材51の長手方向他端側には負極の引出端子60が接合されている。各導電部材51は、蓋部材15の内面15dと電極組立体12のタブ側端面12aとの間に配置されている。   A negative electrode conductive member 51 is joined to the negative electrode tab group 36. A negative electrode tab group 36 is joined to one end in the longitudinal direction of the negative electrode conductive member 51. A negative electrode lead terminal 60 is joined to the other end in the longitudinal direction of the negative electrode conductive member 51. Each conductive member 51 is disposed between the inner surface 15 d of the lid member 15 and the tab-side end surface 12 a of the electrode assembly 12.

次に、正極端子構造16及び負極端子構造17を説明する。なお、正極端子構造16と負極端子構造17は概ね同じ構成であるため、共通の部材については、同じ部材番号を使用して説明する。また、図3には、負極端子構造17のみを図示する。   Next, the positive terminal structure 16 and the negative terminal structure 17 will be described. Since the positive electrode terminal structure 16 and the negative electrode terminal structure 17 have substantially the same configuration, common members will be described using the same member numbers. FIG. 3 shows only the negative electrode terminal structure 17.

図1又は図3に示すように、蓋部材15は、長手方向における両側に係止凸部18を備える。各係止凸部18は、外面15cから厚み方向に沿って突出した形状である。蓋部材15を外面15cから見て、係止凸部18は、蓋部材15の長手方向に長手が延びる突条形状である。各係止凸部18は、蓋部材15の短手方向の中央に位置する。蓋部材15は、長手方向における各係止凸部18より外側に挿通孔15eを備える。   As shown in FIG. 1 or FIG. 3, the lid member 15 includes locking projections 18 on both sides in the longitudinal direction. Each locking projection 18 has a shape protruding from the outer surface 15c along the thickness direction. When the lid member 15 is viewed from the outer surface 15 c, the locking projection 18 has a ridge shape that extends in the longitudinal direction of the lid member 15. Each locking projection 18 is located at the center in the short direction of the lid member 15. The lid member 15 includes an insertion hole 15e on the outer side of each locking projection 18 in the longitudinal direction.

正極端子構造16及び負極端子構造17は、蓋部材15の外面15cに配置された外側絶縁部材57を備える。外側絶縁部材57は、電気的絶縁性を有する合成樹脂製である。正極端子構造16において、外側絶縁部材57は、後述する正極の外部接続端子66及び端子接続部材44を蓋部材15から絶縁する。負極端子構造17において、外側絶縁部材57は、負極の外部接続端子66及び端子接続部材44を蓋部材15から絶縁する。   The positive terminal structure 16 and the negative terminal structure 17 include an outer insulating member 57 disposed on the outer surface 15 c of the lid member 15. The outer insulating member 57 is made of a synthetic resin having electrical insulation. In the positive electrode terminal structure 16, the outer insulating member 57 insulates a positive external connection terminal 66 and a terminal connection member 44 described later from the lid member 15. In the negative electrode terminal structure 17, the outer insulating member 57 insulates the negative external connection terminal 66 and the terminal connection member 44 from the lid member 15.

外側絶縁部材57は、蓋部材15の外面15cから見て矩形状である。外側絶縁部材57の長手は、蓋部材15の長手方向に沿い、外側絶縁部材57の短手は、蓋部材15の短手方向に沿う。外側絶縁部材57は、蓋部材15の外面15cに対峙する裏面57aと、裏面57aと平行な表面57cを有する。外側絶縁部材57において、裏面57aと表面57cを結ぶ方向を厚み方向とする。   The outer insulating member 57 has a rectangular shape when viewed from the outer surface 15 c of the lid member 15. The length of the outer insulating member 57 is along the longitudinal direction of the lid member 15, and the short side of the outer insulating member 57 is along the short direction of the lid member 15. The outer insulating member 57 has a back surface 57a that faces the outer surface 15c of the lid member 15, and a front surface 57c that is parallel to the back surface 57a. In the outer insulating member 57, the direction connecting the back surface 57a and the front surface 57c is the thickness direction.

外側絶縁部材57は、長手方向の一端寄りに、裏面57aから厚み方向に凹んだ回り止め凹部59を備える。回り止め凹部59は、蓋部材15の長手方向に長手が延びる細長状である。回り止め凹部59の開口形状は、蓋部材15を外面15cから見た係止凸部18の外形状と相似である。   The outer insulating member 57 includes a rotation stopper recess 59 that is recessed from the back surface 57a in the thickness direction near one end in the longitudinal direction. The anti-rotation recess 59 has an elongated shape that extends in the longitudinal direction of the lid member 15. The opening shape of the rotation preventing recess 59 is similar to the outer shape of the locking projection 18 when the lid member 15 is viewed from the outer surface 15c.

外側絶縁部材57は、回り止め凹部59に係止凸部18が挿入された状態で蓋部材15の外面15cに設置されている。回り止め凹部59の内側面は、係止凸部18の外側面に接触している。ここで、蓋部材15はケース部材14に固定されている。このため、係止凸部18の外側面に対する回り止め凹部59の内側面の当接により、外側絶縁部材57は、蓋部材15の外面15cに沿う方向への移動が規制されている。   The outer insulating member 57 is installed on the outer surface 15 c of the lid member 15 in a state where the locking protrusion 18 is inserted into the rotation stopper recess 59. The inner side surface of the rotation stopper recess 59 is in contact with the outer surface of the locking projection 18. Here, the lid member 15 is fixed to the case member 14. For this reason, the movement of the outer insulating member 57 in the direction along the outer surface 15c of the lid member 15 is restricted by the contact of the inner surface of the anti-rotation recess 59 with the outer surface of the locking projection 18.

外側絶縁部材57は、長手方向の他端寄りに挿通孔57dを備える。挿通孔57dは、蓋部材15の挿通孔15eと一致した位置にある。外側絶縁部材57は、縁から厚み方向へ四角枠状に突出した形状の係止リブ58を備える。   The outer insulating member 57 includes an insertion hole 57d near the other end in the longitudinal direction. The insertion hole 57d is at a position that coincides with the insertion hole 15e of the lid member 15. The outer insulating member 57 includes a locking rib 58 having a shape protruding from the edge in the thickness direction in a square frame shape.

正極端子構造16及び負極端子構造17は、蓋部材15の外側に配置された外部接続端子66を備える。外部接続端子66は蓋部材15の外側で、二次電池10同士を電気的に接続するバスバー69を締結可能とする。外部接続端子66は金属製である。   The positive terminal structure 16 and the negative terminal structure 17 include an external connection terminal 66 disposed outside the lid member 15. The external connection terminal 66 is capable of fastening a bus bar 69 that electrically connects the secondary batteries 10 to each other outside the lid member 15. The external connection terminal 66 is made of metal.

外部接続端子66は、円板状のボルト頭部67と、外部接続端子66の軸方向に沿ってボルト頭部67の一端面から突出した形状の軸部68とを備える。軸部68には、バスバー締結用のナット78が螺合可能である。ボルト頭部67は、軸部68より大径である。   The external connection terminal 66 includes a disk-shaped bolt head 67 and a shaft portion 68 having a shape protruding from one end surface of the bolt head 67 along the axial direction of the external connection terminal 66. A nut 78 for fastening the bus bar can be screwed onto the shaft portion 68. The bolt head 67 has a larger diameter than the shaft portion 68.

正極端子構造16及び負極端子構造17は、前述の引出端子60を備える。各極性の引出端子60は、それぞれ導電部材51と電気的に接続され、各導電部材51を介してタブ群36と電気的に接続されている。よって、引出端子60は電極組立体12と電気的に接続されている。引出端子60は、後述の端子接続部材44と電気的に接続される接続用軸部60aと、導電部材51と電気的に接続される基部60bとを軸方向に連続して備える。引出端子60は、基部60bを導電部材51に接合して導電部材51と一体化されている。   The positive terminal structure 16 and the negative terminal structure 17 include the above-described lead terminal 60. Each polarity lead terminal 60 is electrically connected to the conductive member 51, and is electrically connected to the tab group 36 via each conductive member 51. Therefore, the lead terminal 60 is electrically connected to the electrode assembly 12. The lead terminal 60 includes a connecting shaft portion 60 a that is electrically connected to a terminal connecting member 44 described later and a base portion 60 b that is electrically connected to the conductive member 51 in the axial direction. The lead terminal 60 is integrated with the conductive member 51 by joining the base 60 b to the conductive member 51.

正極端子構造16及び負極端子構造17は端子接続部材44を備える。端子接続部材44は、矩形状である。端子接続部材44は、外側絶縁部材57に臨む裏面44aと、ケース11の外側に臨む表面44bを有する。裏面44a及び表面44bは、平滑面である。端子接続部材44は、裏面44aと表面44bが平行な平板状である。端子接続部材44において裏面44aと表面44bを結ぶ方向を厚み方向とする。端子接続部材44は、長手方向及び短手方向に延びる直線部を備える形状である。   The positive terminal structure 16 and the negative terminal structure 17 include a terminal connection member 44. The terminal connection member 44 is rectangular. The terminal connection member 44 has a back surface 44 a that faces the outer insulating member 57 and a front surface 44 b that faces the outside of the case 11. The back surface 44a and the front surface 44b are smooth surfaces. The terminal connection member 44 has a flat plate shape in which the back surface 44a and the front surface 44b are parallel. A direction connecting the back surface 44a and the front surface 44b in the terminal connection member 44 is defined as a thickness direction. The terminal connection member 44 has a shape including a linear portion extending in the longitudinal direction and the short direction.

端子接続部材44は、長手方向の一端寄りに圧入孔47を備える。圧入孔47は、円形状である。圧入孔47には、ボルト頭部67が圧入されている。ボルト頭部67の圧入孔47への圧入により、外部接続端子66が端子接続部材44に回り止めされた状態で一体化されている。また、外部接続端子66と端子接続部材44は電気的に接続されている。   The terminal connection member 44 includes a press-fit hole 47 near one end in the longitudinal direction. The press-fit hole 47 has a circular shape. A bolt head 67 is press-fitted into the press-fitting hole 47. The external connection terminal 66 is integrated with the terminal connection member 44 being prevented from rotating by press-fitting the bolt head 67 into the press-fitting hole 47. Further, the external connection terminal 66 and the terminal connection member 44 are electrically connected.

端子接続部材44は、長手方向の他端寄りに挿通孔48を備える。挿通孔48は、端子接続部材44を厚み方向に貫通する。挿通孔48は円形状である。挿通孔48には、引出端子60の接続用軸部60aが挿通されている。接続用軸部60aは、後述の内側絶縁部材40の挿通孔40a、蓋部材15の挿通孔15e、外側絶縁部材57の挿通孔57d及び端子接続部材44の挿通孔48を貫通している。   The terminal connection member 44 includes an insertion hole 48 near the other end in the longitudinal direction. The insertion hole 48 penetrates the terminal connection member 44 in the thickness direction. The insertion hole 48 is circular. The connecting shaft portion 60 a of the lead terminal 60 is inserted through the insertion hole 48. The connecting shaft portion 60 a passes through an insertion hole 40 a of the inner insulating member 40 described later, an insertion hole 15 e of the lid member 15, an insertion hole 57 d of the outer insulating member 57, and an insertion hole 48 of the terminal connection member 44.

端子接続部材44は、裏面44aが外側絶縁部材57の表面57cに支持されているとともに、外側絶縁部材57によって蓋部材15から絶縁されている。端子接続部材44の側縁44fの外側には、係止リブ58が位置している。係止リブ58は、端子接続部材44の側縁44f全体を取り囲む位置にある。係止リブ58が端子接続部材44の表面44bより突出しないように、表面57cからの係止リブ58の突出寸法は、端子接続部材44の厚みより小さく設定されている。   The terminal connection member 44 is supported by the front surface 57 c of the outer insulating member 57 on the back surface 44 a and is insulated from the lid member 15 by the outer insulating member 57. A locking rib 58 is located outside the side edge 44 f of the terminal connection member 44. The locking rib 58 is in a position surrounding the entire side edge 44 f of the terminal connection member 44. The protruding dimension of the locking rib 58 from the surface 57 c is set smaller than the thickness of the terminal connection member 44 so that the locking rib 58 does not protrude from the surface 44 b of the terminal connection member 44.

正極端子構造16及び負極端子構造17は、シールリング65を有する。シールリング65には、引出端子60の接続用軸部60aが挿通されている。シールリング65は、引出端子60の基部60bに支持されている。また、正極端子構造16及び負極端子構造17は、接続用軸部60aが挿通された前述の内側絶縁部材40を有する。内側絶縁部材40は、四角板状である。   The positive terminal structure 16 and the negative terminal structure 17 have a seal ring 65. A shaft portion 60 a for connection of the lead terminal 60 is inserted through the seal ring 65. The seal ring 65 is supported by the base portion 60 b of the lead terminal 60. Moreover, the positive electrode terminal structure 16 and the negative electrode terminal structure 17 have the above-described inner insulating member 40 through which the connecting shaft portion 60a is inserted. The inner insulating member 40 has a square plate shape.

内側絶縁部材40の内側には、シールリング65が配置されている。内側絶縁部材40は基部60bを覆っている。内側絶縁部材40は、蓋部材15と引出端子60の接触を規制するとともに、蓋部材15と引出端子60とを絶縁する。   A seal ring 65 is disposed inside the inner insulating member 40. The inner insulating member 40 covers the base 60b. The inner insulating member 40 regulates contact between the lid member 15 and the extraction terminal 60 and insulates the lid member 15 and the extraction terminal 60 from each other.

端子接続部材44の挿通孔48を貫通した接続用軸部60aの先端部が軸方向にかしめられることにより、接続用軸部60aと基部60bによって、内側絶縁部材40、蓋部材15、外側絶縁部材57、及び端子接続部材44が挟持されている。この挟持により、引出端子60が蓋部材15に固定されている。シールリング65は、蓋部材15の内面15dのうち挿通孔15eの周囲に密接し、蓋部材15の挿通孔15eをシールしている。   The tip end portion of the connecting shaft portion 60a penetrating the insertion hole 48 of the terminal connecting member 44 is caulked in the axial direction, whereby the inner insulating member 40, the lid member 15, and the outer insulating member are connected by the connecting shaft portion 60a and the base portion 60b. 57 and the terminal connection member 44 are clamped. By this clamping, the lead terminal 60 is fixed to the lid member 15. The seal ring 65 is in close contact with the periphery of the insertion hole 15 e in the inner surface 15 d of the lid member 15 and seals the insertion hole 15 e of the lid member 15.

また、引出端子60の接続用軸部60aの先端部は、端子接続部材44の表面44bに係止するとともに、この係止によって各極性の引出端子60と端子接続部材44がそれぞれ電気的に接続されている。また、引出端子60の基部60bは、導電部材51に接触し、この接触によって、各極性の引出端子60と導電部材51がそれぞれ電気的に接続されている。   Further, the leading end of the connecting shaft portion 60a of the lead terminal 60 is locked to the surface 44b of the terminal connecting member 44, and the lead terminal 60 and the terminal connecting member 44 of each polarity are electrically connected by this locking. Has been. The base 60b of the lead terminal 60 contacts the conductive member 51, and the lead terminal 60 and the conductive member 51 of each polarity are electrically connected by this contact.

図6(a)に示すように、二次電池10において、底壁14bの長辺に沿う寸法を幅、底壁14bの短辺に沿う寸法を厚み、底壁14bと天板14eとを最短距離で結ぶ対向方向に延びる直線の寸法を高さとする。   6A, in the secondary battery 10, the dimension along the long side of the bottom wall 14b is the width, the dimension along the short side of the bottom wall 14b is the thickness, and the bottom wall 14b and the top plate 14e are shortest. The dimension of a straight line extending in the opposite direction connected by the distance is defined as the height.

二次電池10のケース11内において、蓋部材15の内面15dと、電極組立体12のタブ側端面12aとの間の幅方向への寸法を対向面間距離Mとする。また、二次電池10は、蓋部材15の内面15dと、タブ側端面12aと、一対の長側壁14cの内面と、底壁14bの内面と、天板14eの内面で画定された設置スペースDをケース11内に有する。設置スペースDは、正極端子構造16及び負極端子構造17、導電部材51、及びタブ群36を設置するための空間である。   In the case 11 of the secondary battery 10, the dimension in the width direction between the inner surface 15 d of the lid member 15 and the tab side end surface 12 a of the electrode assembly 12 is defined as a distance M between opposing surfaces. The secondary battery 10 has an installation space D defined by the inner surface 15d of the lid member 15, the tab-side end surface 12a, the inner surfaces of the pair of long side walls 14c, the inner surface of the bottom wall 14b, and the inner surface of the top plate 14e. In the case 11. The installation space D is a space for installing the positive electrode terminal structure 16 and the negative electrode terminal structure 17, the conductive member 51, and the tab group 36.

図6(b)に比較例の二次電池71を示す。比較例の二次電池71は、ケース72の幅、厚み及び高さが実施形態のケース11と同じである。比較例の二次電池71において、ケース72は、上方に開口部73aを有するケース本体73と、ケース本体73の開口部73aを閉塞する蓋部材74とを有する。蓋部材74は、実施形態のケース11における天板14eの位置に配置され、天板14eと同じ面積である。実施形態のケース11における天板14eは、その長手方向への寸法(幅)が蓋部材15の長手方向への寸法(高さ)より長く、天板14eの短手方向への寸法(厚み)が、蓋部材15の短手方向への寸法(厚み)と同じである。すなわち、天板14eは、蓋部材15よりも面積が小さい。よって、天板14eと同じ面積を有する比較例の蓋部材74は、実施形態の蓋部材15よりも面積が大きい。言い換えると、実施形態の蓋部材15は、比較例の蓋部材74よりも面積が小さい。   FIG. 6B shows a secondary battery 71 of a comparative example. The secondary battery 71 of the comparative example has the same width, thickness, and height of the case 72 as the case 11 of the embodiment. In the secondary battery 71 of the comparative example, the case 72 includes a case main body 73 having an opening 73 a on the upper side, and a lid member 74 that closes the opening 73 a of the case main body 73. The lid member 74 is disposed at the position of the top plate 14e in the case 11 of the embodiment, and has the same area as the top plate 14e. The dimension (width) in the longitudinal direction of the top plate 14e in the case 11 of the embodiment is longer than the dimension (height) in the longitudinal direction of the lid member 15, and the dimension (thickness) in the lateral direction of the top panel 14e. However, it is the same as the dimension (thickness) of the lid member 15 in the short direction. That is, the top plate 14 e has a smaller area than the lid member 15. Therefore, the lid member 74 of the comparative example having the same area as the top plate 14e has a larger area than the lid member 15 of the embodiment. In other words, the lid member 15 of the embodiment has a smaller area than the lid member 74 of the comparative example.

また、比較例の二次電池71は、蓋部材74の内面74aと、この内面74aに対向した電極組立体75のタブ側端面75aと、一対の長側壁72aと、一対の短側壁72bとで画定された設置スペースD1をケース72内に有する。設置スペースD1において、蓋部材74の内面74aと、電極組立体75のタブ側端面75aとを最短距離で結ぶ直線の長さを対向面間距離M1とする。   Further, the secondary battery 71 of the comparative example includes an inner surface 74a of the lid member 74, a tab side end surface 75a of the electrode assembly 75 facing the inner surface 74a, a pair of long side walls 72a, and a pair of short side walls 72b. The case 72 has a defined installation space D1. In the installation space D1, the length of a straight line connecting the inner surface 74a of the lid member 74 and the tab side end surface 75a of the electrode assembly 75 with the shortest distance is defined as a distance between opposing surfaces M1.

比較例の二次電池71の対向面間距離M1は、タブ群36、導電部材51の設置を考慮すると実施形態の二次電池10の対向面間距離Mと同じになる。上述したように、比較例の蓋部材74の面積は、実施形態の蓋部材15の面積より大きいことから、比較例の設置スペースD1は実施形態の設置スペースDより大きくなっている。すなわち、比較例のケース72内のデッドスペースは、実施形態のケース11内のデッドスペースより大きくなっている。言い換えると、実施形態のケース11内のデッドスペースは、比較例のケース72内のデッドスペースより小さくなっている。比較例のケース72と、実施形態のケース11とが同じ容積であることから、設置スペースの大小関係から実施形態のケース11は、電極組立体12を収容するための容積が比較例より大きい。その結果として、実施形態の二次電池10は、比較例の二次電池71よりも電極組立体12の体積を大きくでき、エネルギ密度が大きくなっている。   The distance M1 between the opposed surfaces of the secondary battery 71 of the comparative example is the same as the distance M between the opposed surfaces of the secondary battery 10 of the embodiment in consideration of the installation of the tab group 36 and the conductive member 51. As described above, since the area of the lid member 74 of the comparative example is larger than the area of the lid member 15 of the embodiment, the installation space D1 of the comparative example is larger than the installation space D of the embodiment. That is, the dead space in the case 72 of the comparative example is larger than the dead space in the case 11 of the embodiment. In other words, the dead space in the case 11 of the embodiment is smaller than the dead space in the case 72 of the comparative example. Since the case 72 of the comparative example and the case 11 of the embodiment have the same volume, the volume of the case 11 of the embodiment for accommodating the electrode assembly 12 is larger than that of the comparative example because of the size of the installation space. As a result, in the secondary battery 10 of the embodiment, the volume of the electrode assembly 12 can be made larger than that of the secondary battery 71 of the comparative example, and the energy density is increased.

また、実施形態の蓋部材15は、比較例の蓋部材74より面積が小さい。このため、正極端子構造16及び負極端子構造17について、蓋部材15の長手方向への寸法は、比較例の正極端子構造76及び負極端子構造77における、蓋部材74の長手方向への寸法より小さい。ただし、異なる二次電池10同士をバスバーで接続した際の電気的な抵抗を低減するため、端子接続部材44は、可能な限り表面44bの面積を大きく確保できる大きさに設計されている。   Further, the lid member 15 of the embodiment has a smaller area than the lid member 74 of the comparative example. Therefore, with respect to the positive electrode terminal structure 16 and the negative electrode terminal structure 17, the dimension in the longitudinal direction of the lid member 15 is smaller than the dimension in the longitudinal direction of the lid member 74 in the positive electrode terminal structure 76 and the negative electrode terminal structure 77 of the comparative example. . However, in order to reduce the electrical resistance when different secondary batteries 10 are connected to each other by a bus bar, the terminal connection member 44 is designed to have a size that can ensure as large an area of the surface 44b as possible.

図3に示すように、バスバー69は、異なる二次電池10同士において、正極端子構造16の外部接続端子66と、負極端子構造17の外部接続端子66を貫通している。バスバー69を貫通した外部接続端子66の軸部68にはナット78が螺合され、バスバー69が端子接続部材44の表面44bに接触した状態で締結されている。端子接続部材44とバスバー69とが接触して形成された接続面により、各端子接続部材44とバスバー69とが電気的に接続され、異なる二次電池10同士が電気的に接続されている。   As shown in FIG. 3, the bus bar 69 passes through the external connection terminal 66 of the positive electrode terminal structure 16 and the external connection terminal 66 of the negative electrode terminal structure 17 in different secondary batteries 10. A nut 78 is screwed into the shaft portion 68 of the external connection terminal 66 penetrating the bus bar 69, and the bus bar 69 is fastened in contact with the surface 44 b of the terminal connection member 44. The terminal connection member 44 and the bus bar 69 are electrically connected by a connection surface formed by contact between the terminal connection member 44 and the bus bar 69, and different secondary batteries 10 are electrically connected to each other.

上記構成の二次電池10は、車両の床下に配置されている。床下において、二次電池10は、底壁14bが載置面上に載置され、天板14eがケース11の上部となる状態に配置される。すなわち、二次電池10は縦置きされる。車両の床下配置では、二次電池10の上側、すなわち天板14eの上側には車両の床があり、床によって二次電池10の高さ方向への移動が規制された状態にある。その一方で、車両の床下配置では、二次電池10の側方、すなわち短側壁14d及び蓋部材15の側方には、空きスペースがある場合が多い。   The secondary battery 10 having the above-described configuration is disposed under the floor of the vehicle. Under the floor, the secondary battery 10 is arranged such that the bottom wall 14 b is placed on the placement surface and the top plate 14 e is the upper part of the case 11. That is, the secondary battery 10 is placed vertically. In the under-floor arrangement of the vehicle, there is a vehicle floor on the upper side of the secondary battery 10, that is, on the top plate 14e, and the movement of the secondary battery 10 in the height direction is regulated by the floor. On the other hand, in the under-floor arrangement of the vehicle, there are often empty spaces on the side of the secondary battery 10, that is, on the sides of the short side wall 14 d and the lid member 15.

次に、二次電池10の作用を記載する。
二次電池10の蓋部材15には、正極端子構造16及び負極端子構造17が蓋部材15の外面15c全体に亘って配置されている。その一方で、圧力開放弁23は、蓋部材15ではなく短側壁14dに配置されている。
Next, the operation of the secondary battery 10 will be described.
On the lid member 15 of the secondary battery 10, the positive terminal structure 16 and the negative terminal structure 17 are disposed over the entire outer surface 15 c of the lid member 15. On the other hand, the pressure release valve 23 is disposed not on the lid member 15 but on the short side wall 14d.

上記実施形態によれば、以下のような効果を得ることができる。
(1)端子接続部材44を含む正極端子構造16及び負極端子構造17は、ケース11の壁部のうち面積の小さい壁部である蓋部材15に配置されている。バスバー69と端子接続部材44との接続面での電気的な抵抗を低くするため、端子接続部材44は表面44bの面積が可能な限り大きくなるように形成されている。このため、蓋部材15の外面15cを広く覆う状態で正極端子構造16及び負極端子構造17が配置されている。このような二次電池10において、圧力開放弁23を蓋部材15ではなく短側壁14dに配置した。短側壁14dには正極端子構造16及び負極端子構造17は配置されていないため、圧力開放弁23の大きさ、配置に制限はなく、ケース11の内圧が開放圧に達した際には圧力開放弁23に必要な開口面積を確保できる。その結果として、ケース11の内圧を下げ、ケース11が損傷を受けることを抑制できる。
According to the above embodiment, the following effects can be obtained.
(1) The positive electrode terminal structure 16 and the negative electrode terminal structure 17 including the terminal connection member 44 are disposed on the lid member 15 which is a wall portion having a small area among the wall portions of the case 11. In order to reduce the electrical resistance at the connection surface between the bus bar 69 and the terminal connection member 44, the terminal connection member 44 is formed so that the area of the surface 44b is as large as possible. For this reason, the positive electrode terminal structure 16 and the negative electrode terminal structure 17 are arrange | positioned in the state which covers the outer surface 15c of the cover member 15 widely. In such a secondary battery 10, the pressure release valve 23 is disposed not on the lid member 15 but on the short side wall 14 d. Since the positive terminal structure 16 and the negative terminal structure 17 are not arranged on the short side wall 14d, there is no limitation on the size and arrangement of the pressure release valve 23, and when the internal pressure of the case 11 reaches the release pressure, the pressure release is performed. An opening area necessary for the valve 23 can be secured. As a result, the internal pressure of the case 11 can be lowered and the case 11 can be prevented from being damaged.

また、ケース11内にガスが発生した際、ガスは、電極組立体12の積層方向の隙間から電極組立体12外へ噴出する。このため、ガスは、短側壁14dに向けて噴出しやすい。この短側壁14dに圧力開放弁23が位置しているため、圧力開放弁23が開裂しやすくなる。   Further, when gas is generated in the case 11, the gas is jetted out of the electrode assembly 12 through a gap in the stacking direction of the electrode assemblies 12. For this reason, the gas is likely to be ejected toward the short side wall 14d. Since the pressure release valve 23 is located on the short side wall 14d, the pressure release valve 23 is easily cleaved.

(2)高さ方向(底壁14bと天板14eの対向方向としての上下方向)への移動が規制された二次電池10において、蓋部材15の面積が小さくなるように、蓋部材15をケース11の側方に配置した。その結果、正極端子構造16及び負極端子構造17の設置によってケース11内に生じる設置スペースDを小さくし、ケース11内に収容できる電極組立体12の体積を大きくし、エネルギ密度を向上させることができる。   (2) In the secondary battery 10 in which movement in the height direction (up and down direction as the facing direction of the bottom wall 14b and the top plate 14e) is restricted, the lid member 15 is arranged so that the area of the lid member 15 is reduced. Arranged on the side of the case 11. As a result, the installation space D generated in the case 11 due to the installation of the positive terminal structure 16 and the negative terminal structure 17 can be reduced, the volume of the electrode assembly 12 that can be accommodated in the case 11 can be increased, and the energy density can be improved. it can.

(3)正極端子構造16及び負極端子構造17は、引出端子60と外部接続端子66とを端子接続部材44で接続する構造である。このため、正極端子構造16及び負極端子構造17は蓋部材15を広く覆う状態になる。よって、圧力開放弁23を短側壁14dに配置する構造は、正極端子構造16及び負極端子構造17を有する二次電池10に特に有用である。   (3) The positive terminal structure 16 and the negative terminal structure 17 are structures in which the lead terminal 60 and the external connection terminal 66 are connected by the terminal connection member 44. For this reason, the positive electrode terminal structure 16 and the negative electrode terminal structure 17 are in a state of widely covering the lid member 15. Therefore, the structure in which the pressure release valve 23 is disposed on the short side wall 14 d is particularly useful for the secondary battery 10 having the positive terminal structure 16 and the negative terminal structure 17.

(4)弧状溝31,32は、直線溝30a,30bに比較して開裂し難い。このため、弧部28,29に接する部分が多い領域S3,S4の面積を、弧部28,29に接する部分が少ない領域S1,S2の面積に比較して大きくすることで、領域S3,S4の受圧面積が大きくなる。したがって、圧力開放弁23の開口面積を大きくするために弧部28,29に沿う弧状溝31,32を有する圧力開放弁23であっても、弧状溝31,32の開裂が促進されることで領域S3,S4が外側に開き易くなる。その結果、圧力開放弁23の開きのバランスが良くなり、圧力開放弁23の開口面積を大きくすることができる。つまり、ケース11内の圧力を迅速に開放させることができる。   (4) The arc-shaped grooves 31 and 32 are harder to cleave than the straight grooves 30a and 30b. For this reason, by increasing the area of the regions S3 and S4 with many portions in contact with the arc portions 28 and 29 as compared with the areas of the regions S1 and S2 with few portions in contact with the arc portions 28 and 29, the regions S3 and S4. The pressure receiving area becomes large. Therefore, even in the pressure release valve 23 having the arc-shaped grooves 31 and 32 along the arc portions 28 and 29 in order to increase the opening area of the pressure release valve 23, the cleavage of the arc-shaped grooves 31 and 32 is promoted. The regions S3 and S4 are easily opened outward. As a result, the balance of the opening of the pressure release valve 23 is improved, and the opening area of the pressure release valve 23 can be increased. That is, the pressure in the case 11 can be quickly released.

(5)二次電池10の評価試験の一つに釘刺し試験がある。この釘刺し試験では、釘は長側壁14cの中央に刺される場合が多い。電極組立体12において、釘の刺さった部分は短絡が発生し、短絡に伴い発生した熱によって電解液が分解され、ガスが発生する。圧力開放弁23は、短絡の発生した場所の側方に位置するため、釘刺し試験時には、発生したガスを圧力開放弁23から効率良く外部に放出することができる。   (5) One of the evaluation tests of the secondary battery 10 is a nail penetration test. In this nail penetration test, the nail is often stuck in the center of the long side wall 14c. In the electrode assembly 12, a short-circuit occurs in the portion where the nail is pierced, and the electrolyte is decomposed by heat generated by the short-circuit, and gas is generated. Since the pressure release valve 23 is located to the side of the place where the short circuit has occurred, the generated gas can be efficiently discharged from the pressure release valve 23 to the outside during the nail penetration test.

(6)車両の床下配置では、短側壁14dの側方には空きスペースがある場合が多い。このため、圧力開放弁23の開裂が部品等によって妨げられることが抑制され、さらに、圧力開放弁23からのガス放出が妨げられることが抑制される。   (6) In the under-floor arrangement of the vehicle, there is often an empty space on the side of the short side wall 14d. For this reason, it is suppressed that the cleavage of the pressure release valve 23 is prevented by components or the like, and further, the prevention of gas release from the pressure release valve 23 is suppressed.

(7)複数の二次電池10を電気的に接続して電池モジュールとした場合は、隣り合う二次電池10同士は、長側壁14cが対向する状態となる。圧力開放弁23が長側壁14cに位置していると、圧力開放弁23に対向する他の二次電池10の長側壁14cによって圧力開放弁23の開裂が妨げられる虞がある。これに対し、本実施形態では、短側壁14dに圧力開放弁23が位置している。そして、短側壁14dの側方には空きスペースがある場合が多いため、圧力開放弁23の開裂が部品等によって妨げられることが抑制され、さらに、圧力開放弁23からのガス放出が妨げられることが抑制される。   (7) When a plurality of secondary batteries 10 are electrically connected to form a battery module, adjacent secondary batteries 10 are in a state where the long side walls 14c face each other. If the pressure release valve 23 is positioned on the long side wall 14 c, the long side wall 14 c of the other secondary battery 10 facing the pressure release valve 23 may prevent the pressure release valve 23 from being cleaved. On the other hand, in this embodiment, the pressure release valve 23 is located in the short side wall 14d. And since there is often an empty space on the side of the short side wall 14d, it is suppressed that the pressure release valve 23 is prevented from being cleaved by parts and the like, and further, the gas release from the pressure release valve 23 is prevented. Is suppressed.

なお、上記実施形態は以下のように変更してもよい。
○ 圧力開放弁23の形状は、弧部28,29に接する部分が多い領域S3,S4の面積が、弧部28,29に接する部分が少ない領域S1,S2の面積に比較して大きくなれば、境界P1,P2,P3,P4の位置を変更したり、弧状溝31,32の長さを変更したりしてもよい。
In addition, you may change the said embodiment as follows.
○ The shape of the pressure release valve 23 should be larger if the area of the regions S3 and S4 with many portions in contact with the arc portions 28 and 29 is larger than the area of the regions S1 and S2 with less portions in contact with the arc portions 28 and 29. The positions of the boundaries P1, P2, P3, and P4 may be changed, or the lengths of the arc-shaped grooves 31 and 32 may be changed.

○ 交差溝30を、X字状に代えて、Y字状に変更してもよい。
○ 弁体24において溝は、表面24aと平行な裏面に設けてもよい。
○ ケース部材14は、絞り加工以外の方法で形成されてもよい。
The cross groove 30 may be changed to a Y shape instead of an X shape.
(Circle) in the valve body 24, you may provide a groove | channel in the back surface parallel to the surface 24a.
The case member 14 may be formed by a method other than drawing.

○ 短側壁14dにおける圧力開放弁23の位置は適宜変更してもよい。
○ 車両の床下において、二次電池10は、一方の長側壁14cが載置面上に載置されてもよい。すなわち、二次電池10は平置きされてもよい。この場合、ケース11の天板14eは、実施形態のようにケース11の上部ではなく、側部に配置されることとなる。
The position of the pressure release valve 23 on the short side wall 14d may be changed as appropriate.
O Under the floor of a vehicle, as for the secondary battery 10, one long side wall 14c may be mounted on a mounting surface. That is, the secondary battery 10 may be placed flat. In this case, the top plate 14e of the case 11 is arranged not on the top of the case 11 but on the side as in the embodiment.

○ 電極組立体12は積層型でなく、捲回型であってもよい。
○ 蓄電装置は、例えばキャパシタなど、二次電池以外の蓄電装置にも適用可能である。
The electrode assembly 12 may be a wound type instead of a laminated type.
The power storage device can also be applied to power storage devices other than secondary batteries, such as capacitors.

○ 正極電極21及び負極電極19は、金属箔の片面に活物質層が存在する構造でもよい。
○ 二次電池10は、リチウムイオン二次電池でもよいし、他の二次電池であってもよい。要は、正極用の活物質と負極用の活物質との間をイオンが移動するとともに電荷の授受を行うものであればよい。
The positive electrode 21 and the negative electrode 19 may have a structure in which an active material layer is present on one side of a metal foil.
The secondary battery 10 may be a lithium ion secondary battery or another secondary battery. In short, any ion may be used as long as ions move between the active material for the positive electrode and the active material for the negative electrode and charge is transferred.

次に、上記実施形態及び別例から把握できる技術的思想を以下に追記する。
(1)前記圧力開放弁は、前記底壁と前記天板の対向方向における中央部に配置されている蓄電装置。
Next, a technical idea that can be grasped from the above embodiment and another example will be added below.
(1) The power release device, wherein the pressure release valve is disposed at a central portion in a facing direction of the bottom wall and the top plate.

D…設置スペース、Y1,Y2…仮想直線、S1〜S4…領域、10…蓄電装置としての二次電池、11…ケース、12…電極組立体、12a…端面としてのタブ側端面、14…ケース部材、14a…開口部、14b…底壁、14c…長側壁、14d…短側壁、14e…天板、15…蓋部材、15d…内面、19…電極としての負極電極、21…電極としての正極電極、23…圧力開放弁、28,29…弧部、30…交差溝、30a,30b…直線溝、31,32…弧状溝、44…端子接続部材、51…導電部材、60…引出端子、66…外部接続端子。   D ... Installation space, Y1, Y2 ... Virtual straight line, S1 to S4 ... Area, 10 ... Secondary battery as power storage device, 11 ... Case, 12 ... Electrode assembly, 12a ... Tab side end face as end face, 14 ... Case 14a ... long wall, 14d ... short side wall, 14e ... top plate, 15 ... lid member, 15d ... inner surface, 19 ... negative electrode as an electrode, 21 ... positive electrode as an electrode Electrode, 23 ... Pressure release valve, 28, 29 ... Arc part, 30 ... Cross groove, 30a, 30b ... Linear groove, 31, 32 ... Arc-shaped groove, 44 ... Terminal connection member, 51 ... Conductive member, 60 ... Lead terminal, 66: External connection terminal.

Claims (4)

異なる極性の電極が互いに絶縁されて積層された電極組立体と、
前記電極組立体を収容したケース部材、及び該ケース部材の開口部を閉塞する矩形状の蓋部材を有するケースと、
前記蓋部材の内面と、該内面に対向した前記電極組立体の端面との間の設置スペースに配置され、かつ前記電極組立体と電気的に接続された各極性の導電部材と、
前記設置スペースで前記各極性の導電部材と電気的にそれぞれ接続され、かつ前記蓋部材を貫通して前記ケースの外部に突出した各極性の引出端子と、
前記ケースの外部に配置され、かつ前記各極性の引出端子とそれぞれ電気的に接続された各極性の端子接続部材と、
前記ケース内の圧力が開放圧に達した場合に開裂し、前記ケース内の圧力を前記ケースの外部に開放させる圧力開放弁と、を備え、
前記ケース部材は、矩形状の底壁と、該底壁の一対の長側縁から立設された一対の長側壁と、前記底壁の一方の短側縁から立設された短側壁と、前記底壁と対向し、一対の前記長側壁と前記短側壁とに接続された天板と、を有し、前記底壁の他方の短側縁側に前記開口部を備え、
前記底壁と、前記一対の長側壁と、前記短側壁と、前記天板と、前記蓋部材とは、それぞれ前記ケースの壁部を形成し、
前記圧力開放弁は、前記壁部のうちの前記短側壁に位置することを特徴とする蓄電装置。
An electrode assembly in which electrodes of different polarities are laminated and insulated from each other;
A case member containing the electrode assembly, and a case having a rectangular lid member for closing an opening of the case member;
A conductive member of each polarity disposed in an installation space between the inner surface of the lid member and an end surface of the electrode assembly facing the inner surface, and electrically connected to the electrode assembly;
A lead terminal of each polarity electrically connected to the conductive member of each polarity in the installation space and penetrating the lid member and projecting to the outside of the case;
A terminal connection member of each polarity disposed outside the case and electrically connected to the lead terminal of each polarity;
A pressure release valve that cleaves when the pressure in the case reaches an open pressure, and releases the pressure in the case to the outside of the case; and
The case member includes a rectangular bottom wall, a pair of long side walls erected from a pair of long side edges of the bottom wall, and a short side wall erected from one short side edge of the bottom wall; A top plate facing the bottom wall and connected to a pair of the long side wall and the short side wall, and having the opening on the other short side edge side of the bottom wall,
The bottom wall, the pair of long side walls, the short side wall, the top plate, and the lid member each form a wall portion of the case,
The power storage device, wherein the pressure release valve is located on the short side wall of the wall portion.
前記ケース部材は、絞り加工によって形成されている請求項1に記載の蓄電装置。   The power storage device according to claim 1, wherein the case member is formed by drawing. 前記圧力開放弁は、該圧力開放弁の周縁の一部を構成する弧部と、互いに交差する2本の直線溝を含む交差溝と、該交差溝の端部に繋がるとともに前記弧部に沿う複数の弧状溝とを有し、前記交差溝に沿って延長し、かつ前記圧力開放弁の周縁と交差する2本の仮想直線を想定したとき、前記各仮想直線と前記圧力開放弁の周縁とによって囲まれた第2の領域と、前記各仮想直線と前記弧部とによって囲まれた第1の領域とが想定され、前記第1の領域の前記弧部に接する部分が前記第2の領域の前記弧部に接する部分よりも多くなるように前記第1及び第2の領域が構成され、前記第1の領域の面積が、前記第2の領域の面積よりも大きい請求項1又は請求項2に記載の蓄電装置。   The pressure relief valve is connected to an arc portion constituting a part of the peripheral edge of the pressure relief valve, an intersecting groove including two linear grooves intersecting each other, an end portion of the intersecting groove and along the arc portion A plurality of arcuate grooves, extending along the intersecting grooves, and assuming two virtual straight lines intersecting the peripheral edge of the pressure relief valve, the virtual straight lines and the peripheral edge of the pressure relief valve; A first region surrounded by each virtual straight line and the arc portion, and a portion of the first region in contact with the arc portion is assumed to be the second region. The first and second regions are configured so as to be larger than a portion in contact with the arc portion, and the area of the first region is larger than the area of the second region. 2. The power storage device according to 2. 前記蓄電装置は二次電池である請求項1〜請求項3のうちいずれか一項に記載の蓄電装置。   The power storage device according to any one of claims 1 to 3, wherein the power storage device is a secondary battery.
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Cited By (6)

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JP2019003881A (en) * 2017-06-19 2019-01-10 リチウム エナジー アンド パワー ゲゼルシャフト ミット ベシュレンクテル ハフッング ウント コンパニー コマンディトゲゼルシャフトLithium Energy and Power GmbH & Co. KG Power storage element and power storage module
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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019003881A (en) * 2017-06-19 2019-01-10 リチウム エナジー アンド パワー ゲゼルシャフト ミット ベシュレンクテル ハフッング ウント コンパニー コマンディトゲゼルシャフトLithium Energy and Power GmbH & Co. KG Power storage element and power storage module
WO2021208969A1 (en) * 2020-04-16 2021-10-21 宁波吉利汽车研究开发有限公司 Power battery pack and vehicle
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CN117525774A (en) * 2024-01-08 2024-02-06 深圳海辰储能科技有限公司 Energy storage device and electric equipment
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