JP2018006106A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent liquid leakage as a corner part of a case deforms when a power storage device is dropped without increasing the number of components.SOLUTION: A secondary battery (power storage device) 10 has a case 11 which has a case body 12 in a four-sided shape with an opening part and a lid body 13 closing the opening part, and an electrode assembly accommodated in the case 11. Then an electrode terminal (minus terminal 27) provided protruding from the lid body 13 is provided with an insulating plate (outer insulating member 21b) and a metal plate (terminal connection member 26) such that they are arranged between the electrode terminal and the lid body 13 with the insulating plate on the side of the lid body 13. The outer insulating member 21b is provided while an end face 21Ef corresponding to a longer-directional end of the lid body 13 is located outside at a position where it comes into contact with a virtual plane P1 at 45° to a corner part 11a extending in a shorter direction of the case 11.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power storage device, and more particularly to a power storage device characterized by a liquid leakage prevention structure.

  Conventionally, secondary batteries such as lithium ion secondary batteries have been installed in vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) as power storage devices for storing electric power used in electrical components. Yes. The secondary battery includes a case, an electrode assembly housed in the case, and two electrode terminals that protrude outside the case and have different polarities.

  As shown in FIG. 7A, as a battery (storage element), a pair of positive electrode terminal portion 20A and negative electrode terminal portion 20B includes connection pieces 30A and 30B and lower packings 40A and 40B, respectively. And the structure by which upper packing 50A, 50B, connection body 60A, 60B, and electrode part 63A, 63B was provided in the cover body 100 is disclosed (refer patent document 1). The pair of positive and negative electrode terminal portions 20A and 20B are attached to the lid 100 by rivets 10A and 10B. The pair of electrode terminal portions 20A and 20B have substantially the same configuration.

  Of the members constituting the electrode terminal portion 20 </ b> A on the positive electrode side, the connection piece 30 </ b> A and the lower packing 40 </ b> A are arranged on the inner side surface of the lid body 100. The connection piece 30A is formed by bending or punching the other end of the current collector 70A (the end opposite to the side connected to the positive electrode plate), As shown in FIG. 7B, the whole is formed in a plate shape of an isosceles trapezoid. The connecting piece 30A is formed to be vertically long, that is, larger in height than the lengths of the upper and lower bases, and the trapezoidal height direction (the left-right direction in FIG. 7B) is the longitudinal direction.

  A lower packing 40A is sandwiched between the connection piece 30A and the inner surface of the lid 100. The lower packing 40A is insulative, has heat resistance and corrosion resistance, and is formed of an elastic material so as to be in close contact with the lid 100 and prevent leakage of the electrolytic solution.

Republished WO2012-133785

  A secondary battery test includes a drop test in which a corner of the casing is dropped. When an impact is applied to the corner portion of the casing during the drop test and the corner portion is crushed, there is a problem in that the internal terminal is deformed and the sealing performance of the terminal seal portion is impaired to cause liquid leakage. In order to pass the drop test, it is necessary that even if the drop test is performed, the sealing performance of the terminal seal portion is not impaired and liquid leakage does not occur.

  The power storage device generally contains an electrode assembly and an electrolytic solution in a rectangular box-like case (housing), and it is necessary to reduce the space in order to increase the capacity per volume of the power storage device. . Some power storage devices include a current interrupt mechanism that interrupts current in response to an increase in internal pressure of the case. In the case of a power storage device including a current interruption mechanism, the space in the case is small, particularly on the negative electrode side where the current interruption mechanism is provided. Therefore, for example, as shown in FIG. 8, when the power storage device 200 falls from a corner side of the case to a hard surface 90 such as the ground and the corner portion is deformed, the corner portion on the side close to the current interruption mechanism In some cases, the sealing performance of the terminal seal portion is impaired, and liquid leakage may occur.

  Patent Document 1 aims to make it possible to securely maintain airtightness, and the upper packings 50A and 50B and the coupling bodies 60A and 60B are not concerned with protecting the corners of the container (case) when the battery is dropped. Not suggested.

  The present invention has been made in view of the above-described problems, and its purpose is to prevent the corner portion of the case from being deformed and causing liquid leakage when the power storage device falls without increasing the number of parts. It is an object of the present invention to provide a power storage device that can be used.

  A power storage device that solves the above problem is a power storage device that includes a rectangular box-like case body having an opening, a case having a lid that closes the opening, and an electrode assembly housed in the case. is there. And the electrode terminal provided in a state protruding from the lid body is provided in a state where the insulating plate and the metal plate are disposed between the lid body in a state where the insulating plate is on the lid body side, The insulating plate is provided such that a portion corresponding to an end portion in the longitudinal direction of the lid body is located outside a position in contact with an imaginary plane forming 45 ° with a corner portion extending in a short direction of the case. It has been.

  When the power storage device falls from the lid side where the electrode terminals are provided, the impact is greatest when the lid falls at an angle of 45 ° with respect to a collision surface such as the ground or the floor. When the lid directly collides with the collision surface, the case is deformed by an impact applied to the corner of the lid, and the deformation of the sealing portion of the electrode terminal seal portion is impaired due to the deformation. Sometimes. However, in the power storage device of the present invention, since the insulating plate and the metal plate are provided in a state of being disposed between the insulating plate and the lid in a state where the insulating plate is on the lid side, the power storage device has dropped from the lid side In this case, the insulating plate collides with the collision surface. As a result, it is avoided that the case body side receives a large impact. Therefore, without increasing the number of parts, it is possible to prevent the case from being deformed and causing liquid leakage when the power storage device falls. Of course, not only the impact received from the collision surface when the power storage device falls, but even when other impact is applied to the corner of the case, it is avoided that the case lid receives a large impact due to the impact, The case can be sealed to prevent liquid leakage.

  The insulating plate may extend so as to be flush with the wall surface of the case body. Even if the insulating plate does not extend so as to be flush with the wall surface of the case body, the lid may drop at an angle of 45 ° to the collision surface such as the ground or floor, When an impact is applied, an impact force is prevented from being applied at an angle of 45 ° to the lid. However, in the configuration in which the insulating plate is provided so as to be flush with the wall surface of the case body, when the lid body falls at an angle smaller than 45 ° with respect to the collision surface, or other impact is applied to the corner portion of the case. Even when it is applied, it is avoided that the case lid is subjected to a large impact by first applying an impact force to the insulating plate.

  The metal plate is provided so as to be flush with the wall surface of the case body. According to this configuration, when an impact force is applied to the corner portion of the case, the impact force is borne not only by the insulating plate but also by the metal plate, so that the impact applied to the lid of the case by the impact force becomes weaker.

  According to the present invention, it is possible to prevent the corner portion of the case from being deformed and causing liquid leakage when the power storage device falls without increasing the number of components.

The schematic perspective view which shows the secondary battery of one Embodiment. The longitudinal cross-sectional view of the part of the electric current interruption mechanism of a secondary battery. (A) is a schematic perspective view explaining an effect | action, (b), (c) is a typical fragmentary sectional view explaining an effect | action. The schematic perspective view explaining an effect | action. (A), (b) is a fragmentary sectional view which shows the secondary battery of another embodiment. (A), (b) is a fragmentary sectional view which shows the secondary battery of another embodiment. (A) is sectional drawing which shows the electrode terminal part of the secondary battery of a prior art, (b) is a figure which shows the state by which the connection piece and the lower packing were attached to the cover body. The schematic perspective view which shows the state of a drop test.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, a secondary battery 10 as a power storage device includes a case 11, and the case 11 closes a rectangular box-shaped case body 12 and an opening 12a (shown in FIG. 2) of the case body 12. And a rectangular flat lid 13. An electrode assembly 14 is accommodated in the case 11. An outer insulating member 21 a as an insulating plate constituting the positive terminal structure 20 and an outer insulating member 21 b as an insulating plate constituting the negative terminal structure 22 are arranged on the outer surface of the lid 13. The outer insulating members 21a and 21b are made of a synthetic resin such as PE, PP, or PPS. In addition, the secondary battery 10 of this embodiment is a lithium ion battery.

  As shown in FIG. 1, the positive electrode terminal structure 20 has a positive electrode terminal 24 and a positive electrode lead terminal 25 as electrode terminals electrically connected by a terminal connecting member 23 as a metal plate, and has an outer insulation as an insulating plate. The member 21 a insulates the positive electrode terminal 24 and the positive electrode lead terminal 25 from the lid body 13. The terminal connection member 23 is made of aluminum.

  As shown in FIG. 1, the negative electrode terminal structure 22 has a negative electrode terminal 27 and a negative electrode lead terminal 28 as electrode terminals electrically connected by a terminal connection member 26 as a metal plate, and has an outer insulation as an insulating plate. The member 21b insulates the negative electrode terminal 27 and the negative electrode lead terminal 28 from the lid body 13. The positive electrode lead terminal 25 is electrically connected to the positive electrode tab group via the positive electrode conductive member, and the negative electrode lead terminal 28 is connected to the negative electrode tab group 19 (shown in FIG. 2) via the negative electrode conductive member 29 (shown in FIG. 2). Are electrically connected to each other. The terminal connection member 26 is made of copper.

  The electrode assembly 14 includes a plurality of sheet-like positive electrodes and a plurality of sheet-like negative electrodes, and the positive electrodes are present on both surfaces of the positive metal foil (in this embodiment, aluminum foil) and the positive metal foil. A positive electrode active material layer. The negative electrode has a negative electrode metal foil (copper foil in this embodiment) and a negative electrode active material layer present on both surfaces of the negative electrode metal foil. The electrode assembly 14 is a layered type in which a separator is provided between a plurality of positive electrodes and a plurality of negative electrodes to insulate them.

  As shown in FIG. 2, the secondary battery 10 includes a current interrupting mechanism 40 integrated with a negative electrode lead terminal 28 which is a negative electrode terminal. The current interrupting mechanism 40 is disposed inside the case 11, and when the internal pressure of the case 11 reaches a predetermined set pressure, the energization that electrically connects the electrode assembly 14 and the negative electrode lead terminal 28. Cut off the current in the path.

  As shown in FIG. 2, the negative electrode conductive member 29 has an electrode connection portion 29 a electrically connected to the negative electrode tab group 19 and a terminal connection portion 29 b electrically connected to the negative electrode lead terminal 28. The electrode connecting portion 29a is bent so as to be closer to the lid body 13 than the terminal connecting portion 29b.

  The current interruption mechanism 40 is located between the base portion 28a of the negative electrode lead terminal 28 and the terminal connection portion 29b of the negative electrode conductive member 29 as a conductive plate. Specifically, the negative electrode tab group 19 is joined with a negative electrode conductive member 29 for electrically connecting the electrode assembly 14 and the negative electrode terminal structure 22. In this embodiment, the base portion 28 a of the negative electrode lead terminal 28 is electrically connected to the negative electrode conductive member 29 via the current interruption mechanism 40, and the negative electrode conductive member 29 is electrically connected to the negative electrode tab group 19. Thus, an energization path between the electrode assembly 14 and the negative electrode extraction terminal 28 is configured. In other words, the current interrupt mechanism 40 constitutes a part of the energization path when not operating, and interrupts the energization path when operated under the pressure of the gas generated in the case 11.

  As shown in FIG. 2, the negative electrode lead terminal 28 which is an electrode terminal on the side where the current interrupt mechanism 40 is provided is supported by a holder 30. The holder 30 is made of an insulating material (in this embodiment, made of resin (made of PPS)), and is provided in a state of covering the outside of the base portion 28 a of the negative electrode lead terminal 28. More specifically, the holder 30 is substantially cylindrical and has a recess 30a that can accommodate the base portion 28a of the negative electrode lead terminal 28. The cylindrical portion 28b of the negative electrode lead terminal 28 is loosely inserted, and between the cylindrical portion 28b. A sealing member 31 is provided on the surface. A seal member 32 is provided between the holder 30 and the negative electrode conductive member 29.

  As shown in FIG. 2, the current interrupt mechanism 40 includes a contact plate 41 joined to the negative electrode conductive member 29 and the base portion 28 a of the negative electrode lead terminal 28. The contact plate 41 is made of a conductive material, and has a bowl shape that protrudes toward the electrode assembly 14. The contact plate 41 covers the concave portion of the base portion 28a from the electrode assembly 14 side. The outer peripheral portion of the contact plate 41 protruding from the recess of the base portion 28a and the end surface of the base portion 28a are fixed by welding.

  The negative electrode conductive member 29 has a concave portion 29 c formed on the surface opposite to the surface in contact with the annular seal member 32. The negative electrode conductive member 29 is formed with a small thickness at the portion that contacts the contact plate 41 by forming the recess 29c. Further, the negative electrode conductive member 29 is formed with a groove 29 d in a portion that contacts the contact plate 41.

  As shown in FIG. 2, the current interrupt mechanism 40 includes a deformable plate 42 that receives and deforms the internal pressure of the case 11. The deformation plate 42 is a diaphragm made of an elastic material, for example, a metal plate, and is disposed at a position closer to the electrode assembly 14 than the terminal connection portion 29b. The deformation plate 42 has a disk shape and covers the recess 29c from the electrode assembly 14 side. The outer peripheral portion of the deformation plate 42 and the terminal connection portion 29b are fixed by welding over the entire outer periphery of the deformation plate 42. The deformation plate 42 hermetically separates the inside of the case 11 from the outside of the case 11.

  The deformation plate 42 is convex from the lid 13 side to the electrode assembly 14 side (downward) in the normal state, and a portion facing the negative electrode welded portion P in the convex portion is directed to the lid 13. And a protruding protrusion 42a. The protrusion 42a faces the negative electrode welded portion P surrounded by the groove 29d.

  An insulating portion 43 that covers the terminal connection portion 29 b and the deformation plate 42 is provided on the electrode assembly 14 side from the terminal connection portion 29 b and the deformation plate 42 of the negative electrode conductive member 29. The insulating portion 43 is arranged so that the side opposite to the negative electrode tab group 19 is located near the inner surface of the case body 12.

  As shown in FIG. 2, the holder 30 and the negative electrode conductive member 29 are fixed outside the deformation plate 42. The holder 30 is fixed to the negative electrode conductive member 29 by caulking. For example, a plurality of holes are formed in the negative electrode conductive member 29, a protrusion 30b that can be fitted into the hole is formed in the holder 30, and the hole and the protrusion 30b are fitted and fixed. Caulking is performed by heat caulking. The negative electrode conductive member 29 is formed such that the end opposite to the electrode connection portion 29 a is the same distance from the inner surface of the case body 12 as the distance between the holder 30 and the inner surface of the case body 12.

  As shown in FIG. 1, the secondary battery 10 includes an outer insulating member 21 b serving as an insulating plate constituting the negative electrode terminal structure 22 and a terminal connecting member 26 serving as a metal plate serving as an insulating plate constituting the positive electrode terminal structure 20. The outer insulating member 21a and the terminal connecting member 23 as a metal plate are different in shape.

  More specifically, the outer insulating member 21a and the terminal connecting member 23 constituting the positive electrode terminal structure 20 are formed in a rectangular shape having a width shorter than the width of the lid body 13, and the end portion on the opposite negative electrode side is also formed on the lid body 13. It is formed so as to be located inside the end. On the other hand, the outer insulating member 21b and the terminal connecting member 26 constituting the negative electrode terminal structure 22 are formed to have the same width on the positive electrode side as that of the outer insulating member 21a and the terminal connecting member 23, and the width of the end portion on the opposite positive electrode side. It is the same as the width of the lid 13, and is formed in a T-shape in plan view in which the end on the side opposite to the positive electrode is located at the same position as the end of the lid 13.

  As shown in FIGS. 1 and 2, the negative electrode lead terminal 28 provided in a state of protruding from the lid 13 has an outer insulating member (insulating plate) 21b and a terminal connecting member (metal plate) 26, and the outer insulating member 21b. Is provided between the negative electrode lead-out terminal 28 and the lid body 13 in a state in which is on the lid body 13 side.

  As shown in FIG. 3B, the outer insulating member 21 b is an imaginary plane in which an end surface 21 Ef corresponding to the end in the longitudinal direction of the lid 13 forms 45 ° with the corner 11 a extending in the short direction of the case 11. It is provided so as to be located outside the position in contact with P1 (the lower side in FIG. 3B). In this embodiment, the end surface 21Ef of the outer insulating member 21b is provided so as to be flush with the outer surface 12b of the case body 12. Similarly, the terminal connection member 26 is also provided so that an end surface 26Ef corresponding to the end portion in the longitudinal direction of the lid body 13 is flush with the outer surface 12b of the case body 12. That is, the end surface 21Ef of the outer insulating member 21b and the end surface 26Ef of the terminal connection member 26 are provided so as to be flush with the wall surface of the case body 12.

Next, the operation of the secondary battery 10 configured as described above will be described.
Since the secondary battery 10 has the current interruption mechanism 40, when the electrode reaction proceeds abnormally and the pressure in the case 11 becomes equal to or higher than a preset pressure, the deformation plate 42 is deformed toward the lid body 13, The protrusion 42 a breaks the negative electrode welded portion P between the terminal connection portion 29 b and the contact plate 41. As a result, the electrical connection between the negative electrode lead terminal 28 and the negative electrode conductive member 29 is interrupted, and the current in the energization path is interrupted.

  As shown in FIG. 3A, when the secondary battery 10 falls from the side of the lid 13 provided with the electrode terminals, that is, the positive terminal 24 and the negative terminal 27, the lid 13 collides with the ground or the floor surface. The impact is greatest when dropped at an angle of 45 ° to the surface 90. As shown in FIG. 3C, when the lid 13 directly collides with the collision surface 90, the case 11 is deformed by an impact applied to the corner of the lid 13, that is, the corner 11 a of the case 11. Due to the deformation, the sealing performance of the seal portion of the electrode terminal may be impaired to the extent that liquid leakage occurs.

  However, in the secondary battery 10, the outer insulating member (insulating plate) 21 b and the terminal connecting member (metal plate) 26 are arranged between the lid body 13 with the outer insulating member 21 b on the lid body 13 side. Therefore, when the secondary battery 10 falls from the lid 13 side, the outer insulating member 21b collides with the collision surface 90. Therefore, as shown in FIG. 3C, unlike the case where the corner portion 11a of the case 11 directly collides with the collision surface 90, the impact when the secondary battery 10 collides with the collision surface 90 is affected by the outer insulating member 21b. Buffered.

  Therefore, as shown in FIG. 3A, even if the case 11 collides with the collision surface 90 at an angle of 45 °, which is the angle at which the impact received from the collision surface 90 is the largest, the case 11 directly receives the impact from the collision surface 90. Instead of receiving, after the impact is reduced by the terminal connecting member 26 and the outer insulating member 21b, as shown in FIG. 4, it collides with the collision surface 90 in a state close to falling from the side surface. As a result, the impact directly received by the case 11 from the collision surface 90 is reduced, and a large impact is avoided. Therefore, it is possible to prevent the corner portion 11a of the case 11 from being deformed and causing liquid leakage when the secondary battery 10 is dropped without increasing the number of parts. Of course, not only the impact received from the collision surface 90 when the secondary battery 10 is dropped, but also when another impact is applied to the corner 11a side of the case 11, the lid 13 of the case 11 is greatly impacted by the impact. Receiving is avoided, and the sealing property of the case 11 can be secured to prevent liquid leakage.

  Since the secondary battery 10 includes the current interruption mechanism 40 integrated with the negative electrode lead terminal 28 which is a negative electrode terminal, the space in the case 11 is small on the negative electrode side where the current interruption mechanism 40 is provided. Therefore, when the secondary battery 10 receives an impact from the corner 11a side of the case 11, if the impact is large, the case 11 is deformed by the impact applied to the corner 11a, and the deformation of the negative electrode lead terminal 28 is caused by the deformation. The sealing performance of the sealing member 31 may be impaired, and liquid leakage may occur. However, since the impact applied to the secondary battery 10 is alleviated by the terminal connection member 26 and the outer insulating member 21b, liquid leakage can be prevented even when a large impact is received from the corner 11a side of the case 11.

According to this embodiment, the following effects can be obtained.
(1) A secondary battery (power storage device) 10 includes a rectangular box-like case body 12 having an opening 12a, a case 11 having a lid 13 that closes the opening 12a, and an electrode accommodated in the case 11. A power storage device including the assembly 14. And the electrode terminal (negative electrode terminal 27) provided in the state which protrudes from the cover body 13 is an insulation plate (outer insulation member 21b) and a metal plate (terminal connection member 26), and an insulation plate turns into the cover body 13 side. It is provided in the state arrange | positioned between the cover bodies 13 in the state. The outer insulating member 21b is positioned outside the position where the end surface 21Ef corresponding to the longitudinal end of the lid 13 is in contact with the imaginary plane P1 that forms 45 ° with the corner 11a extending in the short direction of the case 11. It is provided to do.

  According to this configuration, when the secondary battery 10 is dropped at an angle of 45 °, which is the angle at which the impact is greatest when the secondary battery 10 falls from the lid 13 side with respect to the collision surface 90 such as the ground surface or the floor surface, The insulating plate (outer insulating member 21b) collides with the collision surface 90. As a result, the lid 13 side of the case 11 is avoided from receiving a large impact. Therefore, it is possible to prevent the corner portion 11a of the case 11 from being deformed and causing liquid leakage when the secondary battery 10 is dropped without increasing the number of parts. Of course, not only the impact received from the collision surface 90 when the secondary battery 10 is dropped, but also when another impact is applied to the corner 11a side of the case 11, the lid 13 of the case 11 is greatly impacted by the impact. Receiving is avoided, and the sealing property of the case 11 can be secured to prevent liquid leakage.

  (2) The insulating plate (outer insulating member 21b) is provided so as to be flush with the wall surface of the case body 12. Even if the insulating plate is not provided so as to be flush with the wall surface of the case main body 12, the case where the lid 13 falls at an angle of 45 ° with respect to the collision surface 90 such as the ground surface or the floor surface or the case 11. When another impact is applied to the corner portion 11a, it is possible to prevent an impact force from being applied to the lid 13 at an angle of 45 °. However, in the configuration in which the insulating plate is provided so as to be flush with the wall surface of the case body 12, when the lid body 13 is dropped with respect to the collision surface 90 at an angle smaller than 45 °, or the corner portion 11 a of the case 11. Even when other impacts are applied to the cover 11, it is avoided that the cover 13 of the case 11 receives a large impact by first applying an impact force to the insulating plate.

  (3) The metal plate (terminal connection member 26) is provided so as to be flush with the wall surface of the case body 12. According to this configuration, when an impact force is applied to the corner portion 11a of the case 11, the impact force is supported not only by the insulating plate (outer insulating member 21b) but also by the metal plate (terminal connection member 26). The impact applied to the lid 13 of the case 11 becomes weaker.

  (4) The metal plate (terminal connection member 26) of the negative electrode terminal structure 22 is made of copper. Therefore, since the strength is higher than that of the metal plate (terminal connection member 23) of the positive electrode terminal structure 20 made of aluminum, it is difficult to be deformed by an impact, and the lid 13 of the case 11 is less likely to receive a large impact.

  (5) Since the secondary battery 10 includes the current interruption mechanism 40 integrated with the negative electrode lead terminal 28 which is an electrode terminal of the negative electrode, the space in the case 11 is on the negative electrode side where the current interruption mechanism 40 is provided. small. Therefore, when the secondary battery 10 receives a large impact from the corner 11 a side of the case 11, the clearance between the case body 12 and the holder 30 is small when the corner 11 a is closer to the current interrupt mechanism 40. For this reason, the holder 30 receives a force and the negative electrode lead terminal 28 is deformed, the sealing performance of the terminal seal portion is impaired, and liquid leakage may occur. However, since the impact applied from the corner 11a side of the case 11 is weakened by the insulating plate (outer insulating member 21b) and the metal plate (terminal connecting member 26), even if the current blocking mechanism 40 is provided, Sealing performance can be secured to prevent liquid leakage.

The embodiment is not limited to the above embodiment, and may be embodied as follows, for example.
The insulating plate (outer insulating member 21b) does not have to be provided so as to be flush with the wall surface of the case body 12, and the end surface 21Ef corresponding to the end in the longitudinal direction of the lid body 13 What is necessary is just to be provided so that it may be located in the outer side rather than the position which contact | connects with the corner | angular part 11a extended in a transversal direction and the virtual plane P1 which forms 45 degrees. For example, as shown in FIG. 5A, the outer insulating member 21b and the terminal connecting member 26 are retracted inward from the outer surface 12b without the end surface 21Ef and the end surface 26Ef being flush with the outer surface 12b of the case body 12. You may provide in a state.

  5B, the end surface 21Ef of the outer insulating member 21b is provided flush with the outer surface 12b of the case body 12, and the end surface 26Ef of the terminal connection member 26 is retracted from the end surface 21Ef of the outer insulating member 21b. It may be provided in a state.

  The end surface 21Ef of the outer insulating member 21b and the end surface 26Ef of the terminal connecting member 26 are provided in a state of being retracted from the outer surface 12b of the case body 12, and the end surface 26Ef of the terminal connecting member 26 is retracted from the end surface 21Ef of the outer insulating member 21b. It may be provided in a state.

  As shown in FIG. 6A, the outer insulating member 21b may be provided in a bent shape so that the end portion protrudes from the outer surface 12b of the case body 12 and the protruding portion is in contact with the outer surface 12b. .

As shown in FIG. 6B, the outer insulating member 21 b may be provided in a shape in which the end portion protrudes from the outer surface 12 b of the case main body 12.
○ When the holder 30 and the conductive plate (the negative electrode conductive member 29) are fixed by caulking, the caulking need not be heat caulking.

○ Fixing of the holder 30 and the conductive plate (the negative electrode conductive member 29) is not limited to caulking. For example, it may be fixed with an adhesive.
The electrode assembly 14 is not limited to the laminated type, and may be a wound type including a long strip-shaped positive electrode, a long strip-shaped separator, and a long strip-shaped negative electrode.

  The secondary battery 10 may be a secondary battery that does not have the current interruption mechanism 40. In the case of the secondary battery 10 that does not have the current interruption mechanism 40, the probability that the corner portion of the case is deformed when the secondary battery 10 is dropped is the same between the negative electrode side and the positive electrode side. In this case, the electrode terminals on the negative electrode side and the positive electrode side are provided in a state where the insulating plate and the metal plate are disposed between the lid body and the insulating plate on the lid body side. And each insulating plate is located outside the position where the end surface corresponding to the end portion in the longitudinal direction of the lid body is in contact with the imaginary plane forming 45 ° with the corner portion extending in the short direction of the case. Is provided.

The power storage device may be a power storage device other than the secondary battery 10 such as a capacitor.
The positive electrode and the negative electrode 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 secondary battery other than the lithium ion secondary battery.
The following technical idea (invention) can be understood from the embodiment.
(1) In the invention according to any one of claims 1 to 3, the power storage device has a current interruption mechanism, and the electrode terminal is a negative electrode terminal.

  (2) In the invention according to any one of claims 1 to 3, the electrode terminals are a positive electrode terminal and a negative electrode terminal.

  P1 ... virtual plane, 10 ... secondary battery as a power storage device, 11 ... case, 11a ... corner, 12 ... case body, 12a ... opening, 12b ... outer surface as wall surface of case body, 13 ... lid, 14 ... an electrode assembly, 21b ... an outer insulating member as an insulating plate, 21Ef ... an end face, 26 ... a terminal connecting member as a metal plate, 26Ef ... an end face, 27 ... a negative terminal as an electrode terminal.

Claims (3)

A power storage device having a square box-like case body having an opening, a case having a lid that closes the opening, and an electrode assembly housed in the case,
The electrode terminal provided in a state protruding from the lid body is provided in a state where the insulating plate and the metal plate are disposed between the lid body and the insulating plate on the lid body side,
The insulating plate is provided such that an end surface corresponding to an end portion in the longitudinal direction of the lid body is positioned outside a position where the end surface is in contact with a corner plane extending in a short direction of the case and forming a 45 ° virtual plane. A power storage device.   The power storage device according to claim 1, wherein the end surface of the insulating plate is provided so as to be flush with a wall surface of the case body.   The power storage device according to claim 1, wherein the metal plate is provided so as to be flush with a wall surface of the case main body.

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