JP6531470B2 - Power storage device - Google Patents

Description

  The present invention relates to a power storage device.

  2. Description of the Related Art In vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles), secondary batteries such as lithium ion batteries are mounted as power storage devices for storing power supplied to a motor serving as a prime mover. The secondary battery has an electrode assembly having a positive electrode and a negative electrode, a case accommodating the electrode assembly, and electrode terminals of the positive electrode and the negative electrode, and electrode terminals of each polarity and the electrode assembly It is electrically connected. A plurality of holding tapes for holding the electrode assembly in the stacking direction of the electrodes are attached to the electrode assembly in which the sheet-like positive electrode and the negative electrode are stacked (see, for example, Patent Document 1). In addition, some secondary batteries include an operating member that operates with gas generated in the case. Examples of this type of actuating member include a pressure release valve that releases the pressure in the case to the outside of the case when the pressure in the case exceeds the set pressure (see, for example, Patent Document 1).

JP-A-7-220753

  In the case of the secondary battery, for example, the pressure is increased by the gas generated from the electrolyte at the time of abnormality such as overcharge. And the actuating member mentioned above receives the pressure from the gas generated in the case, and operates. For this reason, it is preferable for the secondary battery to secure a gas flow path to the actuating member.

  This invention is made in view of such a situation, The objective is to provide the electrical storage apparatus which it is easy to distribute | circulate the gas generated from the electrode assembly in a case.

  An electricity storage device for solving the above problems comprises an electrode assembly in which electrodes of different polarities are alternately stacked in an insulated state, a case in which the electrode assembly and an electrolyte are contained, and the case. A pressure release valve which is positioned and operated by the gas generated in the case to release the pressure in the case to the outside of the case, and pasted from one surface to the other surface of the electrode assembly facing each other And the pressure release valve has a pressure receiving portion for receiving the pressure of the gas, and the holding tape is positioned so as to avoid an opposing portion facing the pressure receiving portion of the pressure release valve. ing.

  According to this, the gas generated in the case is not blocked by the holding tape and reaches the pressure release valve. For this reason, the pressure release valve receives the pressure necessary for operation and can operate well. Therefore, even when the holding tape is used to hold the electrode assembly, the gas can be easily circulated to the pressure release valve.

  In the power storage device, the pressure receiving portion may include a cleavage start point of the pressure release valve, and the opposite portion may include at least the cleavage start point. According to this, the pressure release valve can be cleaved from the cleavage origin, and the pressure in the case can be favorably released out of the case.

  The storage device includes a tab protruding from an end of each electrode of the electrode assembly, a conductive member electrically connected to the tab, and an electrode terminal electrically connected to the conductive member. The electrode terminal is partially exposed from a case wall on which the pressure release valve is located among case walls constituting the case, and the opposing portion is a tab of the electrode assembly from which the tab protrudes The holding tape may be located on a projecting surface and the tab projecting surface is located away from the facing portion. According to this, the holding force of the electrode assembly can be maintained by sticking the holding tape on the tab projecting surface.

  In the power storage device, the holding tape located on the tab projecting surface may be located directly below the electrode terminal. According to this, it is possible to suppress a short circuit between the electrode terminal and the electrode assembly by interposing the holding tape between the electrode terminal and the electrode assembly.

  In the above power storage device, a holding tape having a flow passage of the gas may be attached to the electrode assembly at a portion facing the pressure receiving portion. According to this, while securing the flow passage of gas by the holding tape, the affixing area is also ensured and the electrode assembly is well held.

In the power storage device, the flow passage may be a hole formed in the holding tape. According to this, the flow passage can be easily made.
In the above power storage device, a secondary battery can be mentioned as a preferable example of the power storage device.

  According to the present invention, the gas can be easily circulated to the actuating member.

(A) is a perspective view which shows a secondary battery, (b) is the perspective view which expanded the pressure release valve. The disassembled perspective view of an electrode assembly. The disassembled perspective view of a secondary battery. (A) is a fragmentary sectional view which shows the inside of a secondary battery, (b) is an expanded sectional view of a pressure relief valve. The top view which shows the upper surface of an electrode assembly. The perspective view which shows another example of a holding | maintenance tape. The perspective view which shows another example of a holding | maintenance tape.

First Embodiment
Hereinafter, a first embodiment in which the power storage device is embodied in a secondary battery will be described according to FIGS. 1 to 5.

  As shown in FIG. 1A, a secondary battery 10 as a power storage device includes a case 11. The case 11 includes a bottomed box-like case main body 12 opened at one side, and a flat cover 13 that closes the opening of the case main body 12. The case body 12 and the lid 13 are joined by welding or the like.

  The case 11 has a rectangular box shape, and has a rectangular flat plate-like bottom wall 12a having a long side and a short side, and a plurality of side walls erected from four sides of the bottom wall 12a. The bottom wall 12 a faces the lid 13 that closes the opening of the case body 12. A plurality of side walls are provided on the short sides at the four sides of the bottom wall 12a, and are opposed to the two short side walls 12b and 12c, and two long sides on the four sides of the bottom wall 12a. It consists of 12d and 12e. The long side walls 12d and 12e have a larger area than the short side walls 12b and 12c. The secondary battery 10 of this embodiment is a square battery whose appearance is square. The bottom wall 12 a, the short side walls 12 b and 12 c, the long side walls 12 d and 12 e, and the lid 13 are case walls constituting the case 11.

  The case 11 of the secondary battery 10 contains an electrode assembly 14 and an electrolyte (not shown). The electrolyte contains a component that generates hydrogen gas when an abnormality such as overcharging of the secondary battery 10 occurs, specifically, when the potential of the positive electrode becomes excessively high. The secondary battery 10 also includes a positive electrode terminal 15 and a negative electrode terminal 16 as electrode terminals. The positive electrode terminal 15 and the negative electrode terminal 16 are fastened to the lid 13. Further, a part of the positive electrode terminal 15 and the negative electrode terminal 16 is positioned inside the case 11, and a part thereof protrudes outward from the case 11 (lid 13). In addition, the secondary battery 10 of this embodiment is a lithium ion battery, for example.

  As shown in FIG. 2, the electrode assembly 14 has a structure in which positive electrodes 21 and negative electrodes 22 as electrodes of different polarities are alternately stacked with the separators 23 interposed therebetween. A separator 23 insulates between the negative electrode 22 and the positive electrode 21. The direction in which the positive electrode 21, the negative electrode 22, and the separator 23 are stacked is referred to as the stacking direction of the electrode assembly 14.

  The positive electrode 21, the negative electrode 22, and the separator 23 are rectangular sheets having short sides and long sides. The positive electrode 21 includes a rectangular positive electrode metal foil (for example, aluminum foil) 21 a and a positive electrode active material layer 21 b on both sides of the positive electrode metal foil 21 a. The negative electrode 22 has a rectangular negative electrode metal foil (for example, copper foil) 22 a and a negative electrode active material layer 22 b on both sides of the negative electrode metal foil 22 a.

  The positive electrode 21 has a positive electrode tab 31 having a shape protruding from the end 21 c of the positive electrode 21. Similarly, the negative electrode 22 has a negative electrode tab 32 having a shape protruding from the end 22 c of the negative electrode 22. The positive electrode 21 and the negative electrode 22 are stacked such that the same polarity of the tabs 31 and 32 is arranged in a row.

  As shown in FIG.3 and FIG.4, the electrode assembly 14 of this embodiment is comprised by laminating | stacking the positive electrode 21, the negative electrode 22, and the separator 23, and is comprised by rectangular solid shape. The electrode assembly 14 has a first flat surface 14 a and a second flat surface 14 b opposite to the first flat surface 14 a at both ends in the stacking direction. On the first flat surface 14a and the second flat surface 14b, facing regions in which the positive electrode active material layer 21b and the negative electrode active material layer 22b face each other as viewed in the stacking direction are projected. The electrode assembly 14 further includes a tab-side end surface 14c as a tab protrusion surface on one of four surfaces surrounding the first flat surface 14a and the second flat surface 14b. The electrode assembly 14 has a bottom surface 14d on one of the four surfaces, and the bottom surface 14d faces the tab-side end surface 14c. In addition, the electrode assembly 14 includes side surfaces 14e and 14f on the remaining two surfaces of the four surfaces.

  Each surface of the electrode assembly 14 faces each case wall constituting the case 11 in a state where the electrode assembly 14 is accommodated in the case 11. Specifically, the first flat surface 14 a and the second flat surface 14 b face the long side walls 12 d and 12 e of the case body 12. The tab side end face 14 c faces the lid 13. The bottom surface 14 d faces the bottom wall 12 a of the case body 12. The side surfaces 14 e and 14 f face the short side walls 12 b and 12 c of the case main body 12.

  As shown in FIG. 3, each positive electrode tab 31 is folded back to the other in a state of being gathered to one side in the stacking direction of the electrode assembly 14. Similarly, each negative electrode tab 32 is folded back to the other in a state of being gathered to one side in the stacking direction of the electrode assembly 14. Each positive electrode tab 31 and each negative electrode tab 32 protrude from the tab side end surface 14 c of the electrode assembly 14 and protrude from the tab side end surface 14 c of the electrode assembly 14 toward the lid 13.

  As shown in FIGS. 3 and 4, the secondary battery 10 includes a positive electrode conductive member 40 as a conductive member for electrically connecting the positive electrode tab 31 and the positive electrode terminal 15. The positive electrode conductive member 40 is configured of a single metal plate (in the present embodiment, an aluminum plate). The aluminum plate is preferably in the form of a foil. The positive electrode conductive member 40 exists between the lid 13 of the case 11 and the electrode assembly 14 and is joined to both the positive electrode tab 31 and the positive electrode terminal 15.

  The positive electrode conductive member 40 includes a positive electrode first bonding portion 41 relatively disposed closer to the lid 13, and a positive electrode second bonding portion 42 disposed at a position closer to the electrode assembly 14 than the positive electrode first bonding portion 41. And a curved third positive electrode joint 43 connecting the first positive electrode joint 41 and the second positive electrode joint 42. In the positive electrode first bonding portion 41, each positive electrode tab 31 is welded to the surface (lower surface) opposed to the tab side end face 14c of the electrode assembly 14, and the positive electrode first bonding portion 41 and each positive electrode tab 31 are electrically It is connected. The positive electrode first joint portion 41 of the positive electrode conductive member 40 is a connection portion with the positive electrode tab 31.

  The positive electrode terminal 15 includes a prismatic positive electrode head 51, and a positive electrode shaft 52 that protrudes from the seat surface of the positive electrode head 51 and has a screw groove on the outer peripheral surface. The positive electrode shaft portion 52 protrudes out of the case 11 through a through hole 13 b in the lid 13. The positive electrode shaft 52 is inserted into the insulating O-ring 53. Further, the positive electrode shaft portion 52 is inserted into the flanged ring 54. The flanged ring 54 has a tubular shape that fits into the through hole 13 b.

  A nut 55 is screwed onto the positive electrode shaft 52 from above the flanged ring 54, and the positive electrode terminal 15 and the lid 13 are unitized. The flanged ring 54 is interposed between the positive electrode shaft 52 and the peripheral edge of the through hole 13 b of the lid 13 and between the nut 55 and the lid 13.

  The positive electrode head 51 is disposed in the case 11. The positive electrode second joint portion 42 of the positive electrode conductive member 40 is welded to the surface of the positive electrode head 51 on the side of the electrode assembly 14. Thereby, the positive electrode conductive member 40 and the positive electrode terminal 15 are electrically connected.

  In the secondary battery 10, an insulating first positive electrode insulating member 57 covering a portion of the positive electrode head 51, and an insulating second positive electrode insulating member 58 interposed between the positive electrode conductive member 40 and the electrode assembly 14. And have. The first positive electrode insulating member 57 restricts the contact between the lid 13 and the positive electrode head 51, and is attached to the positive electrode head 51 from the lid 13 side. The first positive electrode insulating member 57 covers a part of the seat surface and the outer peripheral surface of the positive electrode head 51. The second positive electrode insulating member 58 regulates the contact between the positive electrode conductive member 40 and the electrode assembly 14.

  As shown in FIGS. 3 and 4, the secondary battery 10 includes a negative electrode conductive member 60 as a conductive member for electrically connecting the negative electrode tab 32 and the negative electrode terminal 16. The negative electrode conductive member 60 is configured of a single metal plate (in the present embodiment, a copper plate). The copper plate is preferably in the form of a foil. The negative electrode conductive member 60 exists between the lid 13 of the case 11 and the electrode assembly 14.

  The negative electrode conductive member 60 has a negative electrode first bonding portion 61 disposed relatively closer to the lid 13. In addition, as shown in FIG. 4, the negative electrode conductive member 60 is disposed at a position closer to the electrode assembly 14 than the negative electrode first bonding portion 61, and the negative electrode first bonding portion 61 and the negative electrode. And a curved third negative electrode joint 63 connecting the second joint 62. Each negative electrode tab 32 is welded to the surface (lower surface) opposite to the tab side end face 14c of the electrode assembly 14 in the first negative electrode bonding portion 61, and the first negative electrode bonding portion 61 and each negative electrode tab 32 are electrically It is connected. The negative electrode first bonding portion 61 of the negative electrode conductive member 60 is a connection portion with the negative electrode tab 32.

  As shown in FIG. 3, the negative electrode terminal 16 includes a negative electrode head 71 having a prismatic shape, and a negative electrode shaft 72 that protrudes from the seat surface of the negative electrode head 71 and has screw grooves on the outer peripheral surface. The negative electrode shaft 72 projects out of the case 11 through the through hole 13 b in the lid 13. The negative electrode shaft portion 72 is inserted into the insulating O-ring 73. Further, the negative electrode shaft portion 72 is inserted through the insulating flanged ring 74. The flanged ring 74 has a tubular shape that fits into the through hole 13 b.

  A nut 75 is screwed onto the negative electrode shaft 72 from above the flanged ring 74, and the negative electrode terminal 16 and the lid 13 are unitized. The flanged ring 74 is interposed between the negative electrode shaft 72 and the peripheral edge of the through hole 13 b of the lid 13 and between the nut 75 and the lid 13.

  The secondary battery 10 includes a current blocking member 80 provided on the current passage of the negative electrode terminal 16 which is an electrode terminal of one polarity and the electrode assembly 14. The conductive member connected to the electrode terminal (negative electrode terminal 16) of one polarity is the negative electrode conductive member 60. The current blocking member 80 is operated by the gas generated in the case.

  The secondary battery 10 further includes a caulking member 88 that unites the insulating negative electrode insulating member 87 covering the seat surface and the outer peripheral surface of the negative electrode head 71, the negative electrode head 71, and the current blocking member 80. ing. The negative electrode insulating member 87 restricts the contact between the lid 13 and the negative electrode head 71, and is attached to the negative electrode head 71 from the lid 13 side.

  Further, as shown in FIGS. 1, 3 and 4 (a), a pressure release valve 90 is provided in the case 11 of the secondary battery 10. The pressure release valve 90 of this embodiment is located on the lid 13 of the case 11. The pressure release valve 90 has a thin plate-like valve body 91 thinner than the thickness of the lid 13. The valve body 91 is located at the bottom of each recess provided in the upper surface and the lower surface of the lid 13 and is integrally formed with the lid 13. Further, on the surface of the valve body 91, a cleavage groove 92 is provided. The cleavage groove 92 in this embodiment is a groove formed by intersecting two linear grooves in an “X” shape.

  Further, as shown in FIG. 4B, the cleavage groove 92 is a groove having a V-shaped cross section. Thereby, the valve body 91 of the pressure release valve 90 further thins the position of the cleavage groove 92. For this reason, in the valve body 91, the pressure applied from the inside of the case 11 tends to be concentrated at the position of the cleavage groove 92, and in particular, at the intersection P where two linear grooves intersect (shown in FIG. 1B). The pressure applied from the inside of 11 is more likely to be concentrated. Then, the pressure release valve 90 receives the pressure from the gas generated in the case 11, and the pressure is released from the intersection P of the cleavage groove 92 when the pressure in the case 11 exceeds the set pressure. By this cleavage, the pressure in the case 11 is released to the outside of the case. The intersection P of the cleavage groove 92 is assumed as a cleavage origin which is a starting point when the valve body 91 starts cleavage, and the intersection P in this embodiment is located at the center of the valve body 91. Moreover, as shown to Fig.4 (a), the back surface of the valve body 91 of the pressure release valve 90 becomes the pressure receiving part S which receives the pressure from gas.

  Further, as shown in FIGS. 3 and 4A, a plurality of holding tapes t1, t2, t3, t4, t5, and t6 are attached to the electrode assembly 14. Each holding tape t <b> 1 to t <b> 6 holds the electrode assembly 14 in the stacking direction of the positive electrode 21 and the negative electrode 22. The holding tapes t1 and t2 are stuck to the first flat surface 14a, the tab side end surface 14c, and the second flat surface 14b. The holding tapes t1 and t2 are attached at predetermined intervals in the direction along the long sides of the first flat surface 14a and the second flat surface 14b. The direction along each long side of the first flat surface 14a and the second flat surface 14b coincides with the direction along the long side of the tab side end surface 14c. The holding tapes t3 and t4 are stuck to the first flat surface 14a, the side surface 14e, and the second flat surface 14b. The holding tapes t5 and t6 are stuck to the first flat surface 14a, the side surface 14f, and the second flat surface 14b. The holding tapes t3 to t6 are attached at predetermined intervals in the direction along the short sides of the first flat surface 14a and the second flat surface 14b. These holding tapes t1 to t6 are provided from one surface (first plane 14a) to the other surface (second plane 14b) opposite to each other in the electrode assembly 14.

  As shown in FIG. 5, in this embodiment, in the state where the electrode assembly 14 is accommodated in the case 11, the pressure receiving portion S of the pressure release valve 90 (valve body 91 The back side can be projected. In the secondary battery 10 of this embodiment, the pressure receiving portion S of the pressure release valve 90 is projected between the positive electrode tab 31 and the negative electrode tab 32. And in this embodiment, the tab side end surface 14c of the electrode assembly 14 is a surface having the facing portion M facing the pressure receiving portion S of the pressure release valve 90. The pressure receiving portion S and the facing portion M include the cleavage start point (intersection portion P) of the pressure release valve 90.

  In this embodiment, a portion (shown by dot hatching in FIG. 5) of the tab-side end surface 14c that avoids the facing portion M opposed to the pressure receiving portion S described above is a sticking position of the holding tapes t1 and t2. That is, among the holding tapes t1 to t6 attached to the electrode assembly 14, the holding tapes t1 and t2 located on the tab side end surface 14c are located avoiding the portion M facing the pressure receiving portion S of the pressure release valve 90. ing.

  As shown in FIG. 4A, the holding tape t1 is attached close to the end of the tab side end face 14c so as to be located immediately below the positive electrode terminal 15. Similarly, as shown in FIG. 4A, the holding tape t2 is attached close to the end of the tab side end face 14c so as to be located immediately below the negative electrode terminal 16. The ends of the tab side end face 14c in the above description are portions located at corner portions where the tab side end face 14c intersects with the side face 14f and corner portions where the tab end face 14c intersects with the side face 14e. The holding tapes t1 and t2 have the same or substantially the same length (width) in the direction along the long side direction of the first flat surface 14a and the second flat surface 14b. The holding tapes t1 and t2 have the same or substantially the same length along the direction (direction orthogonal to the width) applied to the first flat surface 14a, the tab side end surface 14c, and the second flat surface 14b.

Next, the operation of the secondary battery 10 of this embodiment will be described.
In the secondary battery 10 provided with the pressure release valve 90, when gas is generated inside the case 11 at the time of abnormality, the internal pressure of the case 11 becomes high accordingly. At this time, the pressure in the case 11 is applied so as to expand the valve body 91 outward as the back surface of the valve body 91 thinner than the thickness of the lid 13 becomes the pressure receiving portion S. In addition, stress is generated in the cleavage groove 92 of the valve body 91 by the pressure applied from the inside of the case 11. The pressure release valve 90 is split when the pressure in the case 11 exceeds the set pressure, and the pressure in the case 11 is released to the outside.

  In the electrode assembly 14 of this embodiment, the holding tapes t1 and t2 are disposed on the tab-side end surface 14c so as to avoid the portion M facing the pressure receiving portion S. Thereby, the gas generated through the tab side end face 14c of the electrode assembly 14 is not disturbed by the holding tapes t1 and t2 as shown by the arrow Y in FIG. It will reach section S. That is, in the secondary battery 10 of this embodiment, the flow passage is provided such that the generated gas can easily reach the pressure receiving portion S of the pressure release valve 90 depending on the attachment position of the holding tapes t1 and t2.

Therefore, in this embodiment, the following effects can be obtained.
(1) Even when the holding tapes t1 to t6 holding the electrode assembly 14 are attached, the pressure release valve 90 receives the pressure necessary for operation because the gas flow passage is secured. It works well. This improves the operating performance.

  (2) The holding tapes t1 and t2 are attached by avoiding the opposing portion M of the pressure release valve 90 with the pressure receiving portion S. The pressure receiving portion S includes the cleavage start point (crossing point P) of the pressure release valve 90. For this reason, the pressure release valve 90 can be cleaved from the cleavage origin by pressure receiving the gas in the case 11 by the pressure receiving portion S, and the pressure in the case 11 can be favorably released to the outside of the case.

(3) The holding force of the electrode assembly 14 can be maintained by attaching the holding tapes t1 and t2 to the tab side end face 14c.
(4) In particular, the positioning of the holding tapes t1 and t2 at the end of the tab side end face 14c of the electrode assembly 14 enables the electrode assembly 14 to be held well. Thereby, the short circuit etc. of the electrode by the lamination shift of the electrode assembly 14 etc. can be avoided.

  (5) Further, by interposing the holding tapes t1 and t2 between the electrode terminal (positive electrode terminal 15, negative electrode terminal 16) and the electrode assembly 14, a short circuit between the electrode terminal and the electrode assembly 14 can be suppressed.

  (6) Since the holding tapes t1 and t2 are pasted so as to avoid the portion M facing the pressure receiving portion S of the pressure release valve 90, it is not necessary to apply special processing or the like to the holding tape itself. For this reason, the manufacturing process of the secondary battery 10 can be simplified.

Second Embodiment
Next, a second embodiment in which the storage device is embodied in a secondary battery will be described with reference to FIG. In the embodiments described below, the same components as those of the embodiments already described are denoted by the same reference numerals, and the overlapping description will be omitted or simplified.

  As shown in FIG. 6, in this embodiment, holding tapes t7 having different shapes are attached in place of the holding tapes t1 and t2 of the first embodiment. The holding tape t <b> 7 is attached to the tab-side end surface 14 c of the electrode assembly 14 between the positive electrode tab 31 and the negative electrode tab 32. The holding tape t7 is stuck to the first flat surface 14a, the tab side end surface 14c, and the second flat surface 14b so as to be located immediately below the pressure release valve 90. And the hole 95 used as the flow path of gas is perforate | pierced by the holding tape t7 of this embodiment. The hole 95 has the same shape or almost the same shape as the contour of the pressure release valve 90, and is bored in a portion M facing the pressure receiving portion S of the pressure release valve 90.

Next, the operation of the secondary battery 10 of this embodiment will be described.
In this embodiment, a hole 95 is bored in the portion M of the pressure release valve 90 facing the pressure receiving portion S in the holding tape t7. As a result, the generated gas reaches the pressure receiving portion S of the pressure release valve 90 without being disturbed by the holding tape t7. That is, in the secondary battery 10 of this embodiment, a flow passage is provided so that the generated gas can easily reach the pressure receiving portion S of the pressure release valve 90 by the holding tape t7.

Therefore, in this embodiment, in addition to the effects (1) to (5) of the first embodiment, the following effects can be obtained.
(7) A gas flow passage is formed in the holding tape t7 so that the gas flows to the pressure receiving portion S of the pressure release valve 90. Therefore, with the holding tape t7, it is possible to secure the pasting area while securing the gas flow passage. Therefore, the operation performance of the pressure release valve 90 can be improved, and the electrode assembly 14 can be well held by the holding tape t7. And, in this embodiment, since the holes 95 are formed as a gas flow passage in the single holding tape t7, the flow passage can be easily formed.

The present embodiment may be modified as follows.
As shown in FIG. 7, instead of the holding tape t7 in the second embodiment, the first holding tape t8a and the second holding tape t8b may be connected and attached. Each of the first holding tape t8a and the second holding tape t8b has a laterally open cutout 96. Then, the first holding tape t8a and the second holding tape t8b are connected and attached to form a hole 95a corresponding to the hole 95 of the holding tape t7. The hole 95 a has the same shape or almost the same shape as the contour of the pressure release valve 90, and is located at a portion M of the pressure release valve 90 facing the pressure receiving portion S. Even with this configuration, the same effects as those of the second embodiment can be obtained.

  In the first embodiment, the arrangement of the holding tapes t1 and t2 on the tab-side end surface 14c may be changed as long as the portion M facing the pressure receiving portion S is avoided. For example, the holding tape t1 may be positioned closer to the positive electrode tab 31, and the holding tape t2 may be positioned closer to the negative electrode tab 32. In the first embodiment, the holding tapes t1 and t2 may not be attached if the electrode assembly 14 can be held by the holding tapes t3 to t6.

  In addition to the holding tapes t1 and t2 of the first embodiment, the holding tape t7 of the second embodiment or the first holding tape t8a and the second holding tape t8b of FIG. 7 may be attached.

The arrangement (including the number of pieces) of the holding tapes t3 to t6 on the side surfaces 14e and 14f in the electrode assembly 14 may be changed. Also, a holding tape may be attached to the bottom surface 14d.
In the electrode assembly 14, the opposing portion M of the pressure release valve 90 with the pressure receiving portion S may be present on a surface different from the tab end surface 14c.

The secondary battery 10 may have only the pressure release valve 90.
○ In the first embodiment, as shown in FIG. 5, the holding tape is attached at a position avoiding the entire pressure release valve 90, but the holding tape is at least the cleavage start point (intersection P) of the pressure release valve 90. You may avoid and stick. For example, bonding may be performed avoiding directly below the cleavage groove 92, or as in the case of the cleavage groove 92 of the first embodiment, bonding may be performed avoiding the intersection P if it is a cross groove.

  The positive electrode terminal 15 may be an electrode terminal of one polarity in which the current blocking member 80 is provided. At this time, the conductive member connected to the positive electrode terminal 15 which is an electrode terminal of one polarity is the positive electrode conductive member 40.

  The current blocking member 80 may not be integrated with the electrode terminal. For example, the current path may be located between the negative electrode first joint portion 61 and the negative electrode second joint portion 62 to form a current path, and the current path may be interrupted by receiving the pressure of the gas.

The specific configuration of the current interrupting member 80 may be changed.
The specific configuration of the pressure release valve 90 may be changed. For example, the shape of the valve body 91 or the shape of the cleavage groove 92 may be changed.

The specific configuration of the electrode assembly 14 may be changed. For example, the shapes of the positive electrode 21, the negative electrode 22, and the separator 23 may be changed. For example, it may be square in front view.
An insulating cover may be attached to cover the negative electrode first bonding portion 61 of the negative electrode conductive member 60 and the positive electrode first bonding portion 41 of the positive electrode conductive member 40. The insulating cover is located in the case 11 and between the upper surfaces of the negative electrode first bonding portion 61 and the positive electrode first bonding portion 41 and the back surface of the lid 13. The insulating cover is preferably located so as to avoid the opposing portion M of the pressure release valve 90 with the pressure receiving portion S. For example, a hole serving as a gas flow passage is bored in the opposing portion M with the pressure receiving portion S It may be done.

The secondary battery 10 is also applicable to a secondary battery having an electrolyte containing a component that generates a gas other than hydrogen gas (for example, methane gas, carbon dioxide, carbon monoxide, etc.) at the time of abnormality.
The embodiment is also applicable to power storage devices other than secondary batteries, such as capacitors.

The secondary battery 10 may be a stationary battery for use in a house or the like as well as for a vehicle.
The present invention is not limited to the laminated secondary battery 10, and may be applied to a wound secondary battery in which a strip-shaped positive electrode and a strip-shaped negative electrode are wound and layered.

  DESCRIPTION OF SYMBOLS 10 secondary battery as an electrical storage apparatus 11 case 14 electrode assembly 14c tab side end surface as a surface of an electrode assembly 15 positive electrode terminal as an electrode terminal 16 negative electrode terminal as an electrode terminal 31: positive electrode tab 32: negative electrode tab 40: positive electrode conductive member as a conductive member 60: negative electrode conductive member as a conductive member 90: pressure release valve 95, 95a hole: S pressure receiving portion M: Opposite portion, t1 to t7, t8a, t8b ... holding tape.

Claims (6)

An electrode assembly in which electrodes of different polarities are alternately stacked, and are alternately stacked;
The electrode assembly and a case containing an electrolyte;
A pressure release valve located in the case and operated by gas generated in the case to release the pressure in the case to the outside of the case;
And a holding tape attached from one surface to the other surface of the electrode assembly.
The pressure release valve has a pressure receiving portion for receiving the pressure of the gas,
The holding tape is located so as to avoid an opposing portion facing the pressure receiving portion of the pressure release valve ,
The pressure receiving portion includes a cleavage start point of the pressure release valve,
A storage device in which the pressure receiving portion can be projected to a portion of the electrode assembly facing the pressure receiving portion . Tabs projecting from the ends of each electrode of the electrode assembly;
A conductive member electrically connected to the tab;
An electrode terminal electrically connected to the conductive member;
Among the case walls constituting the case, the electrode terminal is partially exposed from the case wall where the pressure release valve is located,
The opposing portion is on a tab projecting surface of the electrode assembly from which the tab projects,
The power storage device according to claim 1, wherein the holding tape is located on the tab protruding surface so as to avoid the facing portion. The power storage device according to claim 2 , wherein the holding tape located on the tab projecting surface is located directly below the electrode terminal. The power storage device according to any one of claims 1 to 3 , wherein a holding tape having a flow path of the gas is attached to a portion facing the pressure receiving portion on the electrode assembly. The power storage device according to claim 4 , wherein the flow path is a hole formed in the holding tape. The power storage device according to any one of claims 1 to 5 , wherein the power storage device is a secondary battery.